Monday 13 Feb 2017, Dr Marc Molinari, Solent Uni : Non-destructive testing of railway wheel sets
16 people, 1.5 hours
This came from a study part funded by the RSSB , Rail Safety Standards Board. Funded by the rail industry and the govt, to ensure we can enjoy
A map of the Swansea area and a place called Oystermouth? and the
Mumbles. In 1804 a huge need for transporting coal,
iron ore , limestone from the sources onto canals and Swansea dealt
with all that and shipped northwards and eastwards.
In the Mumbles they did not have a road to Swansea but they had all
those materials. The first railway was established to transport that.
A carriage on wheels on rails pulled by horse, the oldest railway.
Q: no it wasn't Tyneforth ? had railways about 100
years before that, horsedrawn on wooden rails . You can still see
the Causeway Arch ? railway bridge, the oldest railway viaduct in
the world. For transporting coal from the mines down to the Tyne .
The Oystermouth Tramrail ? Company built this one, length about 5.5
miles. A few years after being built, the company asked for
permission to transport passengers as well, because there was no road.
The govt approved it. 48 years later the rails were changed from
1290 mm to 1.4m wide gauge. Ultimately 1.4m became the standard
for most of the other railways. In 1877 steampower replaced horses.
Just before 1904 they tried to use a battery powered , accumulator
car. Batteries back then , very rudimentary, jars with liquid
and metal. Very unsuccessful, the trams would not move .
100 years later we now have battery powered cars. 1928
electrification came about . Eventually a road was built,
revenue went down .
Things developed nationally, the rail network of 1963.
Then Beeching , loss of the small goods transport branch
lines. If a railway was not yused it was removed, removed
some that were used. The density of the network changed a lot.
The current Network Rail network high density in SE and the
Liverpool area and Manchester , Glasgow and Edinburgh.
Today there is 16,000km of rail track. Also lots of
private tracks , tourist trains etc. Looking after the
main etwork takes a lot of time testing it. Trains that
check the rail quality , driving along the tracks every day.
Also additional transit systems like london Underground and tram
networks. In 1994 UK was connected to Europe by the
Brittain has one of the densest networks in the world, just looking at
Europe , Britain has 20% of all Europe rail journeys.
That is about 65 billion km passenger journeys per year,
a massive figure.
Railways today, a comfortable smooth ride, lots of us use it. It is
often overcrowded in terms of people and timetables. Few slots
to put additional trains on the network. Its fairly safe , few
accidents considering the billions of miles travelled , probably the
safest form of transport.
So maintainence and looking at the wheels. A maintainence shed
with up to 12 trains at the same time being serviced.
It includes regular servicing, need emptying out of toilets,
oil checks. Contacts between rail and wheel , the wheels , brakes
, the under carriage for missing parts etc. A lot of activity .
Considering just the wheels. Every carriage has 2 boggies
each boggie has 2 wheel sets , 4 wheels , so 8 wheels per
carriage. A low estimate of weight 8 tons per carriage for modern
light weight ones, Siemens 700 series . So 1 ton per wheel bu tthe contact area is about
the size of a 2p coin. The whole weight of a carriage is on a contact
area about the size of a DVD. 8 tons is on the low side, much more for
goods trains. A commuter carriage overloaded with 100 people
may double that weight. The materials of carriages is very light
nowadays. There are heavy things like air conditioning in there .
Q: Take a classic 47 series diesel locomotive that was 114 tons
on 2 boggies , so contact stress on a loco was very high.
You could make diamonds at that pressure.
These contact poins are 1 of the safety critical points because if
something goes wrong there, it could derail the train.
With ongoing impact on public perception of rail travel
and the bottom line of finance of rail operation.
The wheels are made of steel it is the geometry that needs to
be looked at, is any of the profile lost. It is a special profile, they
are constructed to. The profile changes with use , wear and tear.
Ultimately they wear to the point the geometry goes below
the safe limit or it needs to be reprofiled.
There could be surface defects and also subsurface defects , inside the
metal. It could be delamination of steel inside, cracks developing from
the inside to the outside. Also the axle needs inspection.
Typically the wheels are pressed , high pressure and hot , pressed
on to the axle. 1 wheel is about 200Kg, 2 wheels 400k plus
axle similar to 600kg. With brake discs on it can easily be 1 ton .
Its not just 1 type of wheel, some have brake pads inside the
wheel like a car , also ones with track brakes that sit on the
outside . Track brakes used to be more common , brake blocks pulled
against the wheel rim. Siemens trains are going back to tread brakes
because they clean the wheel while its turning and braking so
a nice shiney surface.
Audience: mention of the 1:20 profile on the rim. Steering round corners and
stopping of hunting. In the old days there was no planned stiffness for the
bogie. So you had a wheel set that ran in horn guides. As it went
round a corner , there was nothing to control it until it hit the
horn box and then it was infinitely stiff.
When it wears, you go to a steeper profile , so when you go round a
curve , it wants to steer more and oversteers, corrects, oversteers and knocking noise.
Requires keeping the rim profile to 1 in 20, which means lathe turning
the wheels quite frequently , 100,000 miles, to keep the stability in the
vehicle. Later on they brought in planned stiffness , many components
are now rubberised , so you can go farther down the steeper profile .
The profile nowadays is called a worn profile, P8, P1 was the original
1 in 20. P8 means you don't turn off so much when reprofiling the
wheel. With lots of rubber, vertical , lateral and yaw dampers,
you manage the frequencies that a wheelset could pick up on
going around corners.
A lot of science going into all that, the tread profile and the angle
of the flange. Get the wrong angle on a flange , then you climb
and derail. You can get roll-up on a flange, a toe radius buildup
which can then pick-up on points and derail there.
Thats what we found when we did our research. Tight margins and
limits on those factors.
NDT - means you don't damage something. If want to inspect
internal material, you could break it and then know what was inside.
ND means a method that does not require breaking anything.
You can determine internal crystal structure without any damage.
An early example was the wheel-tapper, an engineer with a long
handle hammer , tapped the wheel, listened to it and based on the
ringing sound he cou,ld hear, healthy wheel or a crack somewhere.
They were very skilled people with very good hearing.
Frequency of inspection, Southern and GTR they have mileage
intervals, but there are also timeage intervals. After 60,000 to
80,000 miles they inspect bogie and train body . Every 32 to 36,000
miles a wheelset examination, measurement and gauge.
Compared to cars, longer interval. In comparison French TGV
trains , a daily automated railside inspection of the underside
and pantographs. Every 5 to 6 days or 4,500 km there is a ?
inspection. Every 18 days, traction motors, boggies are maintained
at the depot. A huge turnover required, building into the
overall running costs of trains. Channel tunnel trains also get weekly
inspections or about 5000km.
Manual measurements are common . The geometry of the rim,
a slide-rule arrangement that tells you the flange height and
thickness, if they get thin, the train could derail at
points. The Swallow gauge? , for looking at the toe radius
on the flange. A magnetic one, clamps on for measuring the tread height
at the centre. Once they go below a certain value, with tight tolerances in mm,
the wheel must be reprofiled on a massive lathe. Train drives into place,
the rail is replaced by the lathe that automatically removes , the norm
is 1.5cm of steel removed. Both sides at the same time. If one side damaged then
both sides have to be turned to match. The other pair of wheels can be
different dimensions but not co-axial wheels.
The lathe rotates the wheels, the carriage goes onto the lathe , the track
drops away,to allow the wheels to be rotated and machined down.
It takes about 45 mins to an hour. This metal removal can be repeated for 4 or 5 times . They come with about 8cm that can be removed , at the
end there must be aminimum of 1.5 cm remaining. Below that
and the whole set of 2 wheels and axle is remelted down for new wheels.
There is a hole in the wheel disc, inject oil at very high pressure
and the wheel comes of the axle, replacement wheels are pressed
on to the axle. GTR they don't do that , they send them off for recycling.
On the same axle , both wheels must bw the same diameter or they
would always be going round corners on straight rails.
Q: Is the train slower after taking a cm or 2 off the diameters?
T%he wheels turn a bit faster and the motors can cope with that.
Also the boggie dips down a bit but the carriage remains horizontal.
Q:Its a different motor driving each axle?
Not all of them, it varies, the 165 class, all wheels are driven ,
using a hydraulic transmission , then all wheel diameters must be very
much the same . For HST trains all 8 cars are undriven, each power
car has 8 driven wheels.
Where you have a driven set, you need to have the friction between
driven wheel and the rail. So what if there is ice on it, or really smooth, say brand new wheel and brand new rail, there is wheel spin. for that situation
there is a sand dispenser on the driven wheels. A tube near it, the
driver presses abutton and sand is squirted out.
On the other hand, this also damages the wheels and track, so always a
balance, get you get the train started .
Similarly with leaves on the line. Leaves sometimes block the wheels
, gets into track brakes. If the wheel does not spin for
some reason , it slides, once it slides , it gets a flat, rubbing steel
There are a ot of condition monitoring systems in use. How do you
measure the profile of a wheel. Do it manually when in a depot
but can you do this while its in service. A number of companies
have come up with systems that can measure trains while running past.
Using a laser projection and a camera, up to about 17mph currently.
So a log is taken for that train at that time , has an issue and should
be removed for further action.
Hand held devices that let engineers measure the profile .
Another system next to the rails with 8 cameras . These days you can have
accelerometrs in hand-held devices , as in mobile phones,
and you know the position and attitude of the device when recording the
laser scan lines , while moving the device.
The olympus system , in a depot , the train is still . The system clamps onto the rail , lifts up the wheel hydraulically . The wheel is turned by the device
and the internals of the wheel is measured by ultrasound, after
squirting on water as a contact material. Measures the reflection
and absortion . Othere systems sit in the rail itself. So a matter of mounting
sensors in the rail to measure the wheel via the firm contact point
between rail and wheel. An electromagnetic field that measures surface
and for a thin layer also interior structure. This has been done experimentally
but whether the right material can be found for the sensor holding
rail replacement section, to hold the whole weight of the train
and small contact surface , without getting damaged in multiple useage.
What are we looking for. Rolling Contact Fatigue, using steel on
steel and rolling one of them , you get slight misshaping of the steel.
That results in small cracks across the tread, less than 1mm in
width, up to about 2cm long. If that is detected then the train must come out of service and be reprofiled.
Wheel-flats, often happens ith leaves on the line. To detect this, they use a
wheel impact load detector. A piece of rail, the train goes over, and if the
wheel does not turn smoothly, a clatter noise, and the detector picks up
those impact noises. If it gets really bad you end up with a
red-hot glowing piece of wheel.
Another defect is hollow tread, the 1 in 20 slope of the tread , hollowing
means the train has to come ou tof service. A difference of 2mm
from true profile, the train has to be taken out.
Cracks from failed material or from heating, very fine cracks.
Fine surface cracks develop into bigger cracks, if detected ,
the train must not even be moved, must be skated into a depot.
Flaking happens a lot, cause by corrossion and also by sand use.
Must be reprofiled if detected.
Flange defects, toe-radius build-up , where metal is pushed up
against the flange and builds up. Often goes along with thinning
of the flange. With thinning, at points the wheel does not slot in
easily , dangerous situation.
Q: When you say pushed is that almost a liquid steel state?
Over time , working metal , by pushing hard enough , then it
Ultrasound , sending an acoustic wave into material.
Magnetic particle inspection where a liquid with dissolved ferro-magnetic
particles within. Apply it to the surface and apply magnetism or electric
current, and there is a small crack, the magnetic field is not
continuous in the material , the ferro-material will accumulate
in the crack and you see a black line, contrast between no crack
and crack area. Its messy, has t o be cleaned up after.
Ultrasound, used wit a gel for coupling the sound into
the material. Can be used without contact gel using an
electromagnetic acoustic transducer.
Eddy currents, electromagnetic currents in the surface.
Radio frequency impedance - smooth material givves no
reaction to applied field , but little cracks can act as
little antennas giving secondary fields at different
frequencies . Then the interpretion of what these measurements
mean in terms of damage or in terms of geometry.
Trying to reconstruct how and where these anomalies are coming from.
Do it properly and you can image 3D properties within the material ,
much like baby-scaner images.
Standard ultrasound uses a coupling gel, messy. Electromagnetic
acoustic transducer uses a magnet staic or electromagnet
and a coil underneath. By pulsing the coil , induces eddyy-currents
in the material, that then creates a force on electrodes ,
Lorentz force, causing an ultrasonic wave inside the material
as standard. Does not require direct contact and gel.
Disadvantage is the signal to noise ratio is difficult to
handle due to the small signals to detect.
We are looking at ways of automating condition
and measurement systems. Engineers working in this industry, having built
up many years of experience , are getting rarer with retirement.
not enough engineers coming through to make up that loss .
At the uni , whenever we have graduates coming out they
immediately get jobs. There are about 80,000 graduates
needed annually that are missing in this and other similar industries
just for the UK. Some say up to 130, 000 engineers short.
If you are an engineering student these days, you can pick where
you want to go after your studies.
Cost saving is always a factor , turning round trains quickly.
You want to make maintainance intervals as long as possible without
losing QC on the wheels. This checking process is time concerning , with
a number of people going around individual wheels.
If that could be automated , 4 to 6 trains a day, the
annual savings would be about 75,000 GBP.
Consistent measuring accuracy is a factor, doing this manually,
shown up in a number of reports, the reading repeatability is very
low, different measurements on different days for the same
person , and differnt people measuring differently.
An automatic checking process should be mor e objective
taking out personal judgement on where a gauge is fitted etc.
If you can capture all that data, the more data you have
and analyse, defects and their detection in future.
Loads of different ways of perhaps automating this.
Roll along a 90cm wheel , you need a length of about 3m.
If in a depot the speed is max 5mph , about 3m/s.
So 1 second to record the detail of the whole circumference.
We CAD analysed different sensor systems and attachement
arrangements . Many depots have inspection pits under the
track. With an inspection pit its easier to attach or install
something that is automated to rise up and do the
inspection. We'ce done 3D acoustic analysis of how waves
travel tthrough the material, reconstructing o nthe inside what
we could see from the outside, extracting the interior picture
is quite a challenging process.
A curious early experiment with a bike wheel. Capturing a rotating
bike wheel , at speed , stitching the pics together for 1 long image.
80,400 pixels x 1920 pixels.
With captured data its always possible to return to it.
Our latest staff member Baxter , a robot type used in industry
in an open-sourc erobotic environment and OS. This one has
6 axes on each arm, with grabbers and sensors and can go
There is a huge amount of software out there , all written in Python.
To me what was amazing with this project was to see the scale
of engineering that goes with railway systems, the things you don't
see as a passenger. The quality of just maintaining wheels is
Is it just the UK where goods trains and passenger trains are
entirely separate, or is this universal, why not clip a goods wagon or 2 on the
back of a passenger train?
Passenger trains have to observe a very strict time scheduling, goods delayed
for an hour is no great problem.
Freight trains are heavier and on some lines have speed restrictions .
I'm surprised we are still using 200 yearold technology, same gauge,
steel wheels on steel rails. Any new wheel technology around?
Standards have changed. Over the last few years the grade of steel
has changed, the wheel profile has changed, P8 now, previously
P1 and P9. The grading at manufacturing of the steel is very
closely defined now. All wheels ,now, after manufacture are
ultrasonoic tested before going into service.
I was thinking rubber tyred wheels perhaps?
There was a big accident in south Germany , due to failure of
a rubber wheel. Base steel wheel, rubber on the outside and then over that
a steel tyre. Used for damping the vibrations from travelling fast
, one of those rubber sections perished or something and the steel rim
came off . Steel wheels ar ecrude but reliable, you can take material
off them and still a solid steel wheel.
There is also steel wheels with a steel tyre on them, so the tyre can
be reprofiled or replaced when worn or recut too low.
There is only a small number of wheelset types allowed, its mainly
down to the grain size of the steel..
I beleive for scheduled mainainence of helicopters, there is
permanent recording of noise in servise for any long term changes
in vibration and noises, is there equivalent for monitoring passenger
coaches? prehaps there is for the engines and traction systems.?
Recent technology developed at Chillworth Scienc ePark by Perpetuum
, vibration monitor. It harvests vibration for energy.
It sits on the axle , vibrates while the train goes along,
like the watches that are self-powered by arm movement.
That energy is stored and at the same time it monitors the
frequency of vibration as tthe wheels go along. If you get a continuous
additional frequency, rathe rthan a temporary one from
going over sand or something, it will detect that and
inform the train information system that then records that.
Yhat data from the train can then go live , via mobile
phone system , or wifi, to the maintainance engineers
for assessment of leave the train in service or take it out.
On cross-rail all those eventual trains have something
like 8 or 10,000 monitors on them, continuously
monotored for all sorts of things. Like aero engines are
these days. ? Then loads of data to process through
If there is a call for doing this, you either get cost savings .
For aero engines these days you don't buy an aero engine
, you buy the power and you only lease the engine when it has power
in it. If it breaks down , you stop paying. The manufacturer wants
to make sure that engine keeps running all the time.
Same with cross-railtrains, if they break down, you stop
renting, until they run again.
It makes sense to have sensing systems on the train rather than
The track is mainained by Network rail, the trains by
train operating companies , but they are owned by rolling-stock
companies. So 3 different companies involved and a lot
of discussion going on now about who does what.
The yellow trains that go round measure the tracks, the whole UK
track is monitored by them continuously, recording the state
of the tracks. Some such trains can reprofile a bit of line
or its necessary to cut a piece out and thermite weld a new rail in place
and then polish the tops.
Any advantage in replacing the chassis with carbon-fibre for
The Siemens 700 series , they are very light, a lot
of aluminium but also a lot of plastic, could be carbon-fibre.
But its expensive if large areas of the fibre.
Is there an addiction to an old style of engineering?
Steel is better in a fire situation. Thousands and thousands of miles
But everything is steel, the footbridges look strong enough to
run a train over it?
We do have new materials . Perhaps othe rcountries can
create new versions of traditional structures, easier.
Go to Japan and bridges are made of bamboo and othe r
different materials, designs that look good and last.
If something is established, we know it works, for using new
materials there is often extra costs for changing manufacturing
methods. Vesper IoW wind turbine makers of very large
strong plastic structures probably could say we could
make such a bridge, but they'd have to change their processing
Sometimes people don't want to change. eg rockets stayed much the
same and then along came SpaceX , mor eefficient
engine, better costs as re-useable. Everyone stands back and
says why didn't we think of that. Trains seem to be stuck
i na rut?
Tesla similarly. Home batteries for solar cells to store
The sand business , is that used a lot or continuously?
Its just used to get moving, blowing sand under. The driver i think
gets a flashing light if they loose traction and then they blow
sand out. Once you are rolling you don't have the friction .
For cars there are all sorts of fancy traction controls, if a wheel
starts to spin.?
Used on trains, not that I'm aware of. There is refgenerative
braking a lot these days. Put the brakes on effectively
puts dynamos in the system and generate electricity
That goes back to the third rail or pantograph or stored on board?
On board I think. They have huge batteries about the
size of this pool table. If they loose power , at crossings or
going through stations where there is not necessarily a third rail.
Pantograph contact is not that continuous either.
Monday 13 Mar 2017, Professor James Anderson, Soton Uni [third return visit ] : The Mathematics of Fractals
33 people, 1.5hr
There is the old saying that one should not drink and derive.
I'll try to get across what we mean as mathematicians , what is a fractal (F).
I'm not going too deep into the maths. I'll work thru 2 basic definitions .
A mathematical step that demonstrates a repeating pattern at every
step and every scale. In a loose sense I have some thing , if I take a small
piece , focus down on that small piece and given infinite resolution,
I blow it up, the result should look like what I started with.
The simplest thing like that is a line. A straight line on a piece of
paper, take a tiny piece of the line, expand it, still something like a line,
repeat and looks like a line. Thats fine but we don't want to think of a line
as a F object. A line is too simple an object to think of as a F.
So we have to be careful with such definitions as looks similar on
any scale. Now to engage your imaginations, the Sierpinski Triangle. A big orange triangle thing, cutting out a middle point, the mid point
of each of the 3 sides. Drawn a triangle between those 3 and cut it out.
That left me with 3 big orange triangles. For each of those I do exactly
the same. Then every time i see an orange triangle I take the middle 3
points of its 3 sides, join them together and get a little triangle,
colour it white , same as cutting out. Just keep going. What F can
make a bit headache inducing at times , is what happens at the
"we just keep going part". The result is an orange regular spider-web like thing.
That is an example of a F. Blow up any piece of it and it looks exacly likke
the original. Fs look the same on any scale, no matter how tiny
a piece you get , on blowing up , you see much as the original looked.
This is a very regular sort of construction. Simple is to take a
piece of line, remove the middle third of it , and I'm left with 2 pieces of
line, each of those remove the middle and I have 4 pieces of line
that are much shorter. Keep doing that , over and over again,
and I get what looks like dust, scattered on the line, known as a
Cantor Set, the middle thirds Cantor Set as I'm
removing the middle third of each. Georg Cantor was a great M of the late 19C
. He came up with things that drove him insane and rendered himself
an outcast in the M community , until we realised he was doing
everything that we fundamentally wanted to do.
He wanted to get a handle on some of these things, how we get a
handle on them.
Another example, doing the same thing repeatedly at smaller and
smaller scales , never stopping. Start with a triangle, not caring about
the inside, just caring about the boundary edge of the triangle.
Repeating something over and over again to get something thats
fractal. Instead of removing the middle third, I replace it with 2
sides of a small equilateral triangle, replacing the flat middle of a line,
with something pointy. I now have 4 pieces of line,
each shorter than the original line, but every time I have a line,
I can do the same thing. Just keep doing the same construction.
At every step, I get something that looks more and more
complicated, fairly quickly. If I can do this infinitely many times,
take a small piece of it and blow it up, I will see exactly the same.
What we call the Koch snowflake is what we end up with many many
times. In areal sense its impossible to draw .
This is where maths separates from the real world. When we do something
infinitely many times and we get something in the limit, which we may
, with any feilty, be able to draw in the actual universe. The actual universe
is fundamentally lumpy , its quantised, its not a continuous
thiung. We Ms would love everything to be continuous.
We can do that same construction all over the place.
So taking the surface of a globe, not the whole globe, I
don't care about the inside, just the surface. I remove a bunch
of big discs, a round bit, remove smaller discs from what remains,
and keep removing smaller and smaller discs. Its harder to
see the regularity compared to my earlier examples. Its harder to
understand the rule that we're using, to remove things. But not
as simple as just removing a middle triangle. Here we don't have the
seeming regularity as with triangles. The field in which i do my
research is a field where we generate fractal objects.
To try to get a handle on this general way of doing things.
The basics is ,things that look the same on every scale. One thing Ms have to
do in our work , we have to define what we mean by things in a fairly
precise way. How do we define "the same on every scale" or similar
on every scale to allow a bit of fuzz. There is some formalism , some structure , to what we mean by same on every scale. I won't tell you what it is ,
as its kind of complicated , I just want you to believe me when I
say , there is a way of being very formal , in a very precise
M sort of way. Iterated function systems is the technical phrase.
We generate things that are properly fractal objects and we get
some nifty pics. In this image, the boundary of everything I
can see is just a circle. You're generating an object
that is very real a fractal but every boundary is justr a circle.
Is that jagged enough to be a fractal thing? because its nowhere near
as jagged as the Koch snowflake when it gets done, incredibly jagged thing.
Appearance depends on what you want to mean by fractal.
For me there is a very precise definition, not that everything looks
the same on every scale . The classical Mandelbrot set object.
A much less regular object than we've seen so far. So the first thing we
can ask is does that thing satisfy the definition of looking the same
on every scale. Take small pieces of the MS, take small pieces and
blow them up , it does not look exactly the same but very
much like the whole thing. How you build a MS is an interesting
juxtoposition of complicated indices?. What the colours are , referring to
speeds of how far points are moving.
Go to you-tube and you can see where someone has taken a point
and just zooms in. Zoom in at a constant speed and you see things that look
almost like the MS , appearing, no matter how deep you go.
So the same basic shape, keeps repeating, and you can find it on the
smallest scale that you want. An unusually shaped object but
you can find copies of it on very small scales and work it back to the
definition of things looking the same on every scale. You need a
loose definition of sameness , to make that. I don't actually like the
definition of things looking the same on every scale.
Go back to the Mathematics of Nature by Benoir Mandelbrot .
It did appear in a paper by Brooks and Mckelski a few years earlier
but they only had a crude line printer and so you could not get
an accurate picture ofall the complexities, they had the M underpinnings
there, but Mandelbrot was a better expositor of M.
Whole positive numbers and 0, ignoring negatives for the time.
The numbers with which we count apples etc. A line is a 1 dimensional
thing. A niaive way of thinking of dimensions is as the degrees of freedom,
how many different directions can we move. On a line its back and forth one
way. A flat table top I can move in 2 directions L,R, forward back.
If I start at one point I can get to any other point purely in those 4 terms.
For a room I can pick a point, then go foreward or back , your foreward and back is diiferent wrt you , L or R and again your L and R is different,
upand down which is the same for you, but it is a pub and it is early.
For a room I need 3 directions . We can think of time as the 4th dimension
and colour being 5th dimension, all sorts of notions of dimension that
we have. What does it mean for a thing to have a dimension that
is not actually a whole number, a different sort of dimension.
Mandelbrots book came out in about 1982 and thats where
we come across non whole number dimensions. He starts
with a question - What is the length of the coastline of Britain.
It depends on how you measure. Take a crude map and takle a
piece of string along the coast, measure the length of the string,
account for the scale of the map and get a number.
If I walked along the beach , trailing a piece of string behind me , do
I go round every small rock, do tide pools count, high water,
low water. i get a curve that looks very jagged and as I refine the
scale on which I'm operating , the length of the coast goes up.
The finer the scale, the longer the coast , as I start working around individual
grains of sand, even working round things that are too smal lto
be seen but still require going around. Mandelbrot said that sometimes
when I'm trying to measur ea thing , using a whole number dimension
is'nt going to work. What is the zero dimension of something. I could
count the number of points. 5 apples in my kitchen, I could count 5.
I could take the length of someting, so 1D, using a length of string , perhaps used repeatedly.
Take something flat like a
pool table I've got area and now how to figure out the area of a
square and I can figure out how many squares to fill my object
even if sometimes I only need parts of squares. For 3D Ihave volume
and can start with a cube and how many do I need to fill up the
space, and sometimes I'll need parts of cubes if close to an edge.
But what does half dimension look like , or log4/log3.
Go back to the Koch snowflake . An equation.
Step 0, the number in front of the colon is the step we are
on. Its my starting point, an equilateral triangle. I make the assumption, it does not matter,
I make the length of each side 1. Adding up the 3 sides I just get 3.
Step1 , each side of the triangle, I've taken away 1/3 of the length and added
2/3, now 4 pieces each of length 1/3, done 3 times as 3 sides.
We now iterate, do it again. At the next step I'd have 16 pieces
on each side , breaking into 4. For each as I start with a length 1/3
each has length 1/9 , replacing the mid with 2 others. 1 piece
becomes 4 pieces but each is 1/3 the original piece , so I
get 16 pieces each of length 1/9 and for all 3 sides of the
original triangle. We just keep going again and again.
Then at step n , for each of the 3 sides I have 4^n pieces
, whatever n happens to be, n is the number of steps.
Each of those has length 1/(3^n) because I keep breaking things into
thirds. So what is the length of the Kock snowflake, using our
usual measur eof lengh a ruler or piece of string.
I started with something of length 3, after n steps I have something
3x (4/3)^n. The problem is that (4/3)^n , as n gets bigger
, it gets bigger and it gets bigger quickly . The Koch snoflake
is not built until I've gone through all possible ends and the length
in the end is infinitr. So if I used a normal measur eof length to
figure out the length of the Koch snowflake , I'd have something
with infinite length , that I could still draw on a piece of paper.
My normal notion of length is not the way to measure the size of the
Koch snowflake. It looks as though it should be a 1D thing, building
it by starting with a line, but as I build it, cutting and replacing
with more spikey pieces, in the end, I get something for which
length does not really make sense. So 1D is not how I should measure
the length of this object, I should not use the normal notion of
length. But I can't really use area because essentially all I've done
is built a curve, as I'm ignoring what's inside. I'm just looking at
the edge, so should not have anything 2D about it.
So thinking about the size of this thing, its not 1 and its not 2.
So it has to be something in between. Thats where we start to look at dimension
not being an integre. What is the appropriate scale to measure size
and that is where fractal, dimension that is not an integre comes from.
There are lots of ways that we as Ms have come up with to measure dimension.
There is topological dimension, Biscani? dimension , Hausdorff dimension named
after Felix Hausdorff and Minkowski Dimension , similarity dimension and lots of others.
For a reasonable object like a line , they are all the same, I would get 1.
For a nice object they are all the same. You could define a nice object
,if all these different notions of dimension are the same.
Thats what Ms like to do all the time, flip things on their heads.
Q: Is nice a proper mathematical term?
It is now. I just said that to the internet so it has to be true, right?
The most commonly used notion of dimension is Hausdorff Dimension.
Its hard to create the Hausdorff dimension of a thing because you have
to do a lot of stuff. I pick a number D for dimension , a guess as to
what the dimension might be. Thinking of it as a variable, no assigned
value yet. I cover the object that I'm dealing with, The Koch
snowflake or the Mandelbrot set or whetever. I cover it with discs,
round things with a centre and a radius. I might need infinitely
many of them. For each way of covering my object with round things
I calculate a number. I take all the radii of the discs, I raise each to
the D power and I add them up. I'm burying something here, how do we
know that adding up infinitely many things , gives us a finite
number. I won't worry about that, sometimes it does , sometimes
it doesn't. If it doesn't then D is a bad choice. I cover my object
with all these discs, so I can no longer see the thing any more , for
all the discs. I calculate this number. So covering my object with plates,
I get a number . Now I take a different way of covering it with plates,
perhaps smaller or bigger plates, or even microscopic plates.
Every way , and the every makes it hard, I cover with plates, I
get a number. Then I take the smallest possible number , out of all
the possible ways . There will be ways of covering with a finite
number of plates, there will be ways of covering with infinitely
many plates. If you pick a nice sort of object, which not all of
them are, every way of covering with plates will have a finite
collection of plates, still covers, but not all the time.
For exceptionally nice objects (again we'll call that a mathematical
term) you get a finite sum. Doesn't work for a line but does for
Koch snowflake and the Mandelbrot set (MS), the Sierpinski curve, it
works with things that you can actually draw.
When I look at this quantity and see how it changes as I change D
weird things happen. When D is small the quantity is infinite, when D
is big, the result is zero. There is a single point in between where it
jumps and where it jumps is the thing we call the Hausdorff Dimension (HD).
I'd be comfortable teaching this area to second or third year undergrads.
I buried a vast amount of material here, what I as a M would find
interesting but over the years I've realised not everyone finds it as
interesting as i do. There is a way, a formula foe calculating the Hausdorff.
For the Koch snowflake its HD is log4/log3 which is somewhere
between 1 and 2. For the MS and just its edge , we think its HD is 2
but we don't actually know. As far as I'm aware its still unsolved.
A structure that looks a bit like wrought-iron work or a Paisley
design. The sort of object I work with on a daily or weekly basis.
Its a HD 1.3 dimensional thing. Its built out of a curve , it has the
property , blow up any piece that looks flat at this scale I would see
the same thing .
How to build a MS. Firstly involves complex numbers.
We have our ordinary numbers, we know how to add them , multiply
them, the distributive laws make sense, the things we do with brackets
all that stuff. Complex numbers are just a bigger set of numbers, expanding
my horizon. Now I'm doing as we did with numbers but as points in the
plane. Instead of being numbers that I'm adding or multiplying points in the
plane. How can I tell where I am in the plane, a 2D thing. I pick a point
I declare to be my origin , then A is my left/rightness and B is up/downes.
That tells me where I am in the plane once i set down my co-ordinates.
There is a way, I won't tell you how, I'm just doing what is called
complex arithmatic, here as just simply points in the plane.
i take a point C in the plane, then I do a complicated process, it starts
by taking the function
f(Z) and send it to Z*Z + C
C is fixed for the moment. I start with 0, get 0^2 + C = C.
I take that C and stick it back in, so f(C) is C^2 + C
Take that and plug it back in so I get (C^2+C)^2 + C
just keep going and 1 of 2 things will happen , either I will stay not
too far from 0 or I will shoot off to infinity.
If i stay close to 0 , I colour C black, if i shoot off then I colour C
white. I do this for every single point in the plane , this is the MS.
The MS is what you get when I do this operation and stay close to 0.
The rule to generate the MS is very simple, shoot off or stay
close to homwe. If I stay close tohome I'm in the MS,
if i shoot off , I'm not. The interesting thing is, this is a very
simple rule but gives an incredibly complicated result. Because
the jaggedness of the boundary of the MS is saying I can have
2 points however close together , which bwhave differently.
No matter how close a point is, it does not tell me what will
happen to that close-by point . Thats what makes things
fractal, I don't have that sort of control.
Going to you-tube and where they do the zooming, its that same
calculation at greater and greater resolution, mor eand more
digits. But the fact you keep seeing the same picture, the MS
however smal la scale, means that this very simple rule is giving
you incredibly complicated output. This sort of thing
bedevils us all the time. There ar elots of things where
what we start off with, may or may not be complicated,
and we have to decide yes or no a tthe end. What we get at unis a lot
is degree classifications. A bunch of things they've done in second year
, a bunch in the third year and we have to decide the classification
for their degree. However wel lyou try and set the rule you'll
always find yourself in a situation where students have incredibly
close results and wwill get a different classification.
Its not a problem with the rules you're setting , its the natur eof the
fact you're trying to take a lot of complicated things and divide them
into 2 buckets or 3 buckets.
I had a project, that regretably I never finished. Someone in the law
department, how the law deals with things like murder or manslaughter, people killing
people , how fractal such things can be in some sense.
How can you make sense of complicated interactions that we have
where this thing or that thing is the outcome, guilty or innocent.
And what the boundary is between 1 side and the other. Often
fractal properties will develop.
One of the things I've learnt from fractals is you get complicated situations
arising from simple rules , where it doesn't matter in the end how you
try to separate where 2 things are close together , you should
get the same answer, because you will never be able to do that.
There will always a situation, no matter how you set the
rule, you'll be able to find close situations that get very
different answeres. Because that is part of the nature
of fractalness, very close things having very differentr
outcomes or behaviours.
Is lightning fractal?
Many phenomena have fractal aspects. Look at Times series of
stock market prices, very jagged curves, those are fractally things.
People have tried to say , is the fact they are fractal , does that
give us a way of handling them and trying to predict the future of
stockmarkets. The answer is no, but people have lost a lot
of money trying to do that. If you look at how lightning
is formed, of electricity going, splitting , going , splitting.
Its about as fractal in the real world as you could possibly get.
If a lightning bolt hiys the right sort of ground, it will fuse the
minerals in the ground and it will carry on the same root-like
structure as in the air. The resulting mineral is called fulgarite, hollow
root/branch structure, underground , maybe extending 10 metres or more.
Booles maths ended up being quite useful. Can fractal analysis
be useful in any discipline?
Someone called Eudice Shramm? did a lot of work on
fractal type things. He was working for Microsoft, he was trying
to understand randomness. There are things we'd love to do
by generating random numbers. Usually we use a Pseudo Random
Number Generator, using properties of integre arithmatic on a very
long scale to generate have properties of being random ,but run it
long enough , you end up in cycles.
He did a lot of analysis on fractal objects , the random walks, trying
to model the stock market. You have to understand fractals to make
sense of things, to understand what random actuallly means.
If you could properly create randomness, there are huge applications
for doing random things. Ways of evaluating things, by collecting random
points and seeing what happens over those points.
Its not as strong a connection as in other maths areas.
So its just pure research?
At the moment I think they are. I have to say this as a pure M,
its unlikely anything I've done research-wise will turn out to
be useful. But i'm not saying it won't ever happ[en, it might
take a while. We're laying the groundwork for others to
use. At the time differential geometry Bernard Riman mid 1800s
, he was just doing it as a thing . It is the basis for Einstein's
Theory of Relativity, about which Rieman would never have guessed.
Tomorrow someone may use fractal things to do something
When someone jumps out of a plane with a parachute over the sea, they cannot
apparently tell how high they are as the waves look the same from all
heights? Does that mean that sea-waves are fractal?
I suspect they do have fractal aspects . Big waves have little waves on top
of them and smaller waves on top of those. I guess the ocean surface
at any frozen moment of time is a little bit more than 2D.
Do you think it might be possible to predict wha tthe sea is doing,
using fractal maths?
If you're trying to picture what is happening at any moment,
then probably not. As a sort of time average, on a larger scale,
thrn more predictable generally. Trying to follow an individual
particle thriugh things , you can't figure out what its doing,
but look at all of them, at once, then you can make reasonable
Go down that track and you will start finding submarines at depth?
I was reading over the weekend about the possibility of using
quanum theory , to detect submarines by looking at incredibly
small variations of gravity, caused by the fact the sub is not made
of water. Both fish and subs are neutrally bouyant but Fish contain more water in comparison to a sub.
So the MS might have a dimension of 2, does that mean its
not a fractal?
It depends on how you define fractal. This wiggly object image is just
the boundary of the MS. Boundaries of things in the plain you
expect to have dimension 1, if it has dimension 2 , then we'd make
an exception for it.
I was wondering about its application to biology, neuron
growth or arteries ? They start at some point, decide
whats around them and make a decision on that.?
Possibly, i've never thought about it.
I suspect someone has considered that, but I've not
encountered it in the literature. I can't read as widely as I'd
like to , as time is finite.
Is time a fractal?
You go into Einstein's theory of relativity . You touch a hot
stove and a second feels like a minute, etc. I don't know.
Can it be used on the expansion of galaxies in the universe?
One of the basic questions, as I understand it , in physics,
that they've not yet resolved. What Einstein called the Theory
of Everything, how the M we use to understand the very small
, QM and the M we use to understand the very large, general
and special relativity. What happens in the middle,
can they be brought together. I don't know if galaxy
expansion use this sort of thing. Some collegues model what we think
is going on in Neutron Stars in terms of magneto-hydrodynamics,
magnetism and fluid flow , are coming together. Its entirely
possible they are getting fractal effects there, because they are trying to model
what it sounds like when 2 black holes run into each other.
To predict the wave signals we would see from gravit ywave detection.
I'm interested in the fractals that are evidently self-similar on varying scales
and the ones that are almost, like the MS where parts become a
bit squished, they are not quite the same. THe MS looks more interesting
because it is fundamentally differing. ?
For me it goes back to how they are constructed. Things like the Sierpinski
Curve are constructed regularly, you're imposing a regularity at the
beginning, that gives you this object. for the 1D equivalent of the Sierpinski
curve, you'd take a line, remove the middle third, for the remaining bits
remove the midle third , you get the Cantor set, the set of dust.
The fact I'm removing thirds is irrelevant, I could remove a random
section out of each interval , at every stagr, I'd still get a fractal
object but I'd have no idea what its actual structure looked like
, if 1/10 out of here, 7/10 out of there , doing random things, as I went down.
A different fine structure just by having a non regular
construction. For the regular objects we casn calculate things about them.
As we know the HD of the Koch is log4/log3, comes from the structure being so
regular. With the snowflake I could say at every point I see a line , I just take a
random set in the middle pf the line, I'd still get a fractal object but I'd
not understand it, nearly as well. The MS is the sort where we have a regular rule
but don't understand it as nearly as well. Fo rme the beauty of the MS is its coming
from the initial rule being simple , but we don't know what its doing at
each individual point, as opposed to the very regular initially constructed objects.
From regular structures , very calculable to structures where we have a vague
idea of whats going on, to knowing something weird is going on but we
can't get our hands on it.
Is it possible to use the re-entrant equations to do rendering ?
If you take any polynomial , you can do the same sort of thing, you generate the
Julia Set by using the same basic idea, take a point , following it by the
iteration, either it goes off to the distance,white, or it stays bounded ,black.
Some of the shapes that have been in the backgrounds of pictures here, are
Julia sets of particular polynomials. For each polynomial you'll
get a pic. The MS is just a very particular case of it.
The fact you are doing it in 2D is just because that is what we can draw.
If I take any dimensional space and I take a function on that space,
start iterating and following points, I can build something. The first
demo of mathematical chaos , due to Karl Lorentz using a weather
model. There isa fractal object sitting in there as well. At a stage he had to
reload , the next day, what he'd been working on previously and rerun
it and got a very different pic. He realised the very small differences you get
by truncating things at 10,20 or 30 decimal points , were having a massive
effect on the outcome of the system. So Lorentz and his butterfly
were the first demos of this deterministic chaos in systems.
Its just that 2 is the dimension that we see. Drawing in 3D is hard.
You've drawn some analogies between fractals and every day life, randomness
and Darwinian evolution , they seem mor emetaphores than mathematically rigorous.
What are the practical uses of this M, some practical examples?
Nope, not being flippant, but I can't.
Prime number theory is used every day , Amazon purchases etc?
Number theory, graph theory which is what I teach at the moment, very practical
applications . Network theory, how you route things through systems of nodes/roads? etc
, fractal analysis is something that its primary use is giving us a language
to describe things rather than a way of attacking problems.
Its not developed to the likes of number theory where we can go from
understanding numbers to building unbreakable codes. i think the closest
we get is trying to understand notions of randomness, still rather
esoteric from a procatical point of view.
There are times I'd like to view myself more as an artist than a M.
Why should we care about fractals?
We don't know what someone in a few years will be able to do
with some of these ideas. Part of what we do in math is saying , here is a
practical question. One of the guys in the applied group of the dept had a
grad student who was looking at the M of air-bubble formation
in crumpets. You want all the holes in a crumpet , equal sized .
Actually a PhD thesis of a quastion. not everything we do is immediately
practical. We're exploring what the universe of math is telling us.
After us, others will latch on to particular bits of our math,
to answer their questions. Not every bit of math we do, will find a home.
Some will but not necessarily in our lifetime.
We just don't know what the useful math of 20 years from now , will be.
Some people are doing very practical things, and some are doing the
exploration of the universe of the possible, so when people need
tools , there are tools available to them, to do the great thing they are
trying to do. Without this, there will be people of the future
asking quastions and there won't be anyone to give them an answer.
Can you do this backwards, something that looks like a fractal , can
you work back to the underlying math?
Yes, sometimes you get some very interesting things through it.
So look at neuron formation , what are the processes underlying that,
can we get a handle on that, can we use that to understand things .
The early people to look into iterative function systems, without it
specifically wanting to build a fern , give it some rules on how to
build a fern, a different set of rules to build something else.
Bu tunderstand what it will build , from an initial set
of rules, there has been some basic work on that. It gets very
complicated, very quickly, and not always predictive.
With ferns are they truly fractal or are they fractal only u pto
a certain amount.?
From a M point of view, nothing in the physical world is
truly fractal, because of the constraints of the physical universe.
The universe is quantised, its not continuous. When you say scale,
you can get to such a small scale , that you cannot replicate
things to a larger scale. Most people would say you don't need to go that far,
look at lots of varying scales, and see the same sorts of structures
and be able to apply the analysis , that people have developed for
handling fractals, not necessarily being able to go to every
scale , but many scales.
Is there a connection or a parallel with series theory?
Such as the Koch snowflake , taking the infinit elimit , have c;lose
parallels with series. There is basic notions that underly series
and fractals and these constructions, where there is a commonality,
of how we're doing things. There are underlying mechanisms that we use with
reckless and wanton abandon.
For the math derived fractal sets like the MS, I believe the coloured
versions are just assigning colours to the number of iterations. Is there a
more aesthetic process than the lumpy clour gradations , giving a nicer image.?
I think that sort of image is pretty beautiful myself. I think that is just due
to how they set up the grid sizes . I think you can do that sort of
thing but it comes back to the basic question . I have a continuum of
possibilities and I'm putting it in a coup[le of buckets and the
differences where I go from one bucke tto another are going to be
fairly stark. I think you will get that lumpiness of colour,
regardless of how you do it, because you are trying to assign
colours to things. You might get interesting boundaries between one colour and
another but if I'm using 5 colours ., I've an infinite number of things
and setting it into 5 colours, so am bound to get some lumpiness.
Is the coastline of the Uk a fractal image, can you derrive
an iterative function for the coastline?
I think there are estimates that the coastline is 1.2 to 1.3 dimensional ,
but it gets back to this fundamental of one scale or many scales.
Its lumpy but not as lumpy as the MS.
For the Cantor Set, taking out the middle third and the next iteration, you
take the middle third out as black bits and fill in the middle third of the
white bits, you end up with ever decreasing dashes . There is clearly a
difference between these 2 approaches and again for the triangle,
empty triangle in the middle and put a filled triangle in there , instead
of punching out, it iends up looking much more regular, than the
fractal set. ?
THe Sierpinski set is very regular loking. If you're
doing a slight variation of that construction you'll probalby
get something that is differenrt, but still very regular, in the
same sort of way that the Sierpinski curve is regular.
You can do all sorts of variations on each of these constructions,
give yourself a finite set of possibilities, pick one at
random , do that thing at each stage. Whenever you have that
finiteness of a set of possibilities, you have a possibility
of getting a control in the end. When you have an infiniteness
of possibilities , that control becomes more difficult and the
calculations become much harder.
Is there a way of looking at your original function , produce an
image from that, but predict the degree of curviness or holeyness?
No . If you look at just quadratic polynomials some of them ,
the Julia set, would be a nice connected piece, for others it
won't be . You can get a huge range of diferent sorts of shapes
coming out of that.
There's no overall determinism for that?
There are people who try , I don't think they've succeeded yet.
Its complicated. Its not clear what information the degree is
actually containing , that gives you control of the outcoming
object. Its one of those questions we've not completely resolved.
So veering into the chaos sort of direction.
You dinner-plate Hausdorff dimension determination. If you took the Koch
snowflake , presumably you will need an infinite number
of circles to cover the triangles?
No , using stuff i haven't told you anything about. When you have a set
like the Koch, it has a property know as compactness. For compactness, I
cover it with an infinite number of plates, there is a finite set
of those plates, that still cover it. Compactness is a hard and
slippery notion. The difference between a Koch snowflake that
is contained within a paper sized thing and a line which just keeps
stretching out. Compactness is trying to capture the fact that it is
contained within a sufficiently large piece of paper. Those sorts of
objects have this property, that however you cover them, a
finite set of thos plates will suffice to cover and you can throw
away almost all of them. Id doesn't matter how you do it. As long
as you cover it initially, with your plates, you can find a finite
set. It might be an incredibly large finite number
of plates, I'm not saying 5, i might say 57 trillion but there are a
finite set. The plates have to overlap , to cover the object.
The Mandelbrot formula, how do you come up with that?
Its about the simplect thing thats interesting.
If I did f(z) is z + c, and do the same thing, you don't get
anything interesting, because everything disappears off.
z^2 + c is the simplest formula , do the process, gives us
something interesting. If i used a different more complicated formula, I'd have
something different to the MS , but the same sort of behaviour.
A set where things stsayed in a neighbourhood and a set theat went off
to infinity and a complicated boundary in between.
The MS was the earliest image produced because it was the
simplest thing they could try. The fractal is really the boundary ,
look in closer there and I'd keep seeing what looks like the
whole boundary. The points on the boundary stay bounded , but might
go out a bit and come back, but always keep coming back. But move away
a tiny bit, but in a particular direction and then they disappear.
A feature of fractalness is , however small a change you make,
make it in the right diredction , you get a completely different
behaviour. So not the case of things starting nearby each othe r
end up close to each other, thats completely broken.
Do you think its just an artefact of human perception that we
find these attractive?
Yes. We draw them in niftey ways and use nice colours , it looks
like there is a light behind and its shining out of the boundary.
Part of it is they just look strange, not in a frightening
way, but again thatas a subjective judgement.
Its niftey becaus eits where I've chosen to work so I have a deep
personal bias to these things.
Would you play with them if they were ugly? You've never found
any ugly ones?
What about the zeroes of the Rieman zeta function??
Thats a whole other talk. Its beautiful but its hard and scarey
but there is a beauty to it. Its niot a fractal thing.
Are the numbers that you're plugging into that iterative
formula , integers or real numbers?
Neither, they're complex numbers, points in the plane. I can think of them
as points in the plane, I know how to add or multiply . For each point in the
plane i can do the iterative process. I have a yes/no answer to the
question , do I stay close to the place I started from.
I'm colouring the MS by the answer to that question.
For practical purposes a complex number is made up of 2 real numbers ,
but are they just integres?
They are fractional numbers.
So is the pattern that you get, dependent on the precision of the arithmatic ?
I'm assuming infinite precision, i can do these calculations to infinitely
many decimal places for every point in the plane . In the fractal
universe this is false, but I do this sort of stuff all the time.
I believe they looked into using something like this for compressing images?
I just don't know about that.
Have you put in a function, worked it through , got an image and gone WOW!,
never seen an image like that before?
I'd not seeen that image before (still on the screen) but I still think
that is a wow. One or twice I've done the I wasn't expecting
Towards the end , you had one I'd not seen before, very curved ?
How was that one built (the "wrought"-irony/ Paisley one) ?
There is a way of building things like this, which is , take a bunch
of circles, where the circles don't overlap but they can touch/tangential.
So a string of beads, big or small beads, then start reflecting
in the beads . There is a way of defining reflection is a circle.
Reflect to a line and you just flip one thing over to there . I can define
reflection in a circle, things stay on the same line out from the
centre but just flipping them. Just keep doing that, and you get shapes
similar to this. That one goes back more than 100 years, interestingly.
Way before computers, there were smart guys who figured out
how to do things, prior to computers. Hand drawing such reflections
is quite an efficient way of drawing such as this.
Does this sort of leaf-like geometric patterning lie behind Paisley wallpaper designs?
I love Paisley . I've thought about selling such images but I don't think
my colour sense will lead me into fashion.
Monday 10 Apr 2017, Prof Anneke Lucassen: Cancer Research UK and the 100,000 Genomes Project
20 people, 1.5hr
The incidence of cancer C, in this country is going up.
2014 the last year of good statistics, just over 350,000 new cases
of all types of C diagnosed . The risk is higher in men than women still.
The incidence list has gone up by 12% since the early 1990s , we don't
quite know why. Probably a combination of some environmental factors
, better at detecting Cs which might have gone away by itself.
We're not dying of other things first. Go back 100 years, lots of
us would have died from other diseases before we got old enough
to develop C.
C survival is improving, overall, total average of all Cs
is 50% of people will survive 10 or more years in the UK, that has
doubled over the klast 40 years, due to treatments and earlier catching
of Cs. There is huge variation in survival between different C types.
Certain skin Cs have a very good survival rate, and brain tumours have
a very poor survival rate. They are completely different diseases
and talking about them as one doesn't make sencse.
C is a disease of cells. Any cell that grows uncontrollably
can become cancerous. Skin cancers, leukaemias where blood cells
overgrow and become cancerous . Gut cells can become cancerous , develop
a bowel tumour . Nerve cells can become cancerous to develop a
brain tumour or a glyoma for example. Cell division is very
important in C. We need cells to divide, to grow from baby
to adult . We need cells to divide to heal when we are cut.
And to replace general wear and tear in our bodies.
Every time a cell divides it has to copy itself , copy its genetic material
and a chance that something goes wrong in that copying process.
Whilst I've been talking we've all made about 1/2 million new red
blood cells , to give an idea of the scale. 12 million new gut cells ,
all happening routinely in our bodies. It is routine and controlled, a sytem
of trafic lights around our cell division , saying go or stop
, finely balanced. When that balance is interrupted and the stop
signal is interfered with, for a variety of different reasons
, thats what goes wrong in C. Then the uncontrolled growth
of cells , that then compete with other cells around them. Squash surrounding
tissues or spread to other parts of the body.
Its not allgenetics that causes our cells to divide out of control
but it plays a part.
The influences that can make cells divide out of control , because of
faults that have accumulated in that DNA. Environmental
influences are important, hormones can play an important part ,
eg estrogens and breast Cs a clear link. Take the contraceptive
pill or HRT that has an influence on the accumulation of faults
in our DNA. Lots of natural self-regulations. If you copy your
cells , by dividing , then things can go wrong just by chance.
ur immune system is more important than weoriginally thought in the
developement of C, in particular certain virus infections.
From damage to the DNA, C can arise. I will focus on inheritance,
picking up on the bits that are important and those that are not.
Nearly all our body cells, look into the centre , with a microscope,
the nucleus ,inside that are thw chromosomes which are bundles of
genes together with bits between the genes, the chromosomes are made up
of tightly wound DNA. The DNA is joined together by the DNA letters ,
joining the 2 strings together. That is what we talk about as a sequence of
DNA, 2 billion of those letters per cell, composed of 4 different
letters . Those sequances of code, determine the messages sent to
our body. If the messages go wrong , thats when problems can arise.
The exome is 20,000 different genes, that are sections of that DNA.
The genome is all our genetic material in one cell, all together, the genes
and the bits between.
The word genome derrives from the words gene and chromosome.
Just 1 letter change in all that sequence can be enough to cause
really dramatic changes to our bodies, but it all depends on where
that letter change occurs. All of us have several different
mutations within our genetic code. If those occur in points of the code
that don't do much , then no consequences. Some of those changes
can occur right now as I'm speaking, a mutation in one cell
then copied to the daughter cell. Some of those mutations are inherited from our parents. Inherited in our cells, 2 copies , one from each parent.
Often if you have a mutatuion in one copy , that might disadvantage
you but alone is not enough t cause a problem because the other copy
needs to be knox=cked out. The other copy can be sort of rescuing
the bad copy, or the bad copy over-riding the normal one.
For different diseases there are fdifferences there. For C , often
the case , you might inherit one copy that puts you at a disafdvantage
but its only when the other copy is knocked out by chance
or radiation exposure or something like that, that the C arises.
All C is genetic but not all C is inherited. Any C arises as the
result of genetic faults in the dNA but most of those faults
are not inherited. The difference between inherited forms of C
and chance or sporadic forms of C is if you have inherited
a C predisposing gene , you start off life at a disadvantage.
In order for the C to arise you need more than 1 mutation
or bits of damage to the DNA. There is a required sequence of lots of
different steps to arise before the C starts. Then if you have inherited one
of them , you start off disadvantaged. Thats why i nthe inherited forms of
C we tend to see C at a much younger age, that in the sporadic forms of
C, because they started with a disadvantage and needed fewer
steps to accumulate , before the C arises.
When we talk of inherited Cs , thats not new . Aldred Warsin? described
a family beteen 1895 and 1915 who had very young onset Cs.
This involved bowel and womb Cs, he described it as an unusual
combination of Cs, we now know today as Lintz? syndrome or
heriditary non-polyposis colorectal C and we know the genes that
you inherit t5hat can cause that. But really we've known about this
for over 100 years. And other examples of familial Cs , we've known
about for a long time , from family histories, that there must
be an inherited component, but only in te last few decades
have we found out what that component is.
For breast C an old headline " Her mother died of it , her aunt has it,she has it,
and her 3 daughters" accompanied with the fact that once the gene
was discovered, the test for that woman spared her from
the risk in surgery that she was going to go for, because of her
terrible family history. She had not inherited the gene that was
in her family. The Angelina Jolie effect , she had a BRCA1 gene mutation
inherited from her mother . Her mother had ovarian C at a youing
age and a wider family history of breast C, after had a genetic test
which showed what the cause was in her family and Angelina went
on to have a predictive test for BRCA1 which she had inherited
the same one, and she went on to have risk-reducing mastectomy
and risk-reducing removal of her ovaries.
The demand for BRCA1 testing and the similar BRCA2 gene ,
went up dramatically after her story.
We receive lots of referrals to our genetics service , please test this
person for these 2 genes. A good thing in the sense that she raised the
profile of people who previously were not getting appropriate
testing. But, what many people don't realise, these 2 genes only
explain 5% of all breast and all ovarian Cs. The majority are
explained by other causes. Its not even staightforward to do
that test to find if you are in the 5% category , because the 2 genes
are both very big and the inherited bit can be different in each
family. So the lab has to trawl thru more than 10,000 letters
of genetic code in each gene and look to see if there are any changes
in that gene that have been inherited , that might explain
a family history. We all have those 2 genes and we all have some
variation in those genes and the lab has to try and decipher what is just
normal variation and what is causing the high incidence of
breast and ovarian Cs. The more we test, the more we realise that we find a
variation but it does not mean much. So we have to be very careful
about saying if someone is BRCA1 or 2 positive, because it may be a spurious
red herring finding. I spend a lot of my time telling women ,
intending to be tested, that it is not as simple as they think.
1 in 3 of us will develop a C at some point in our lives and across the
board for all Cs 95% of those will not be due to a single
inherited factor. So in 95% of cases , there may well be an inheritred
componet but that component is very complex consisting of
lots of different factors interacting in ways we don't yet fully
understand. Part of that interaction will also be protection.
One gene protects a bit here , that one increases your
chances or protect in another environment. We just don't know enough
yet to put all that together into 1 algorithm that says with your particular
genetic combination and your particular environmental exposure in
your lifetime, this is your risk of C type x,y or z.
But the headlines make it sound that we are at that point.
The press are more responsible these days but they often mae it sound
, we found a new gene, go to your doctor, get tested for that gene
and you will know or not whether you will get c.
Its not unusual for someone coming to a clinic waving a paper
with a headline like that, can I have a test for these new found genes please.
From a research point of view, finding a new breast C gene is
helpfull as it gives insights into the mechanisms of the disease, but it
often fails to translate into a useful test, unless it is a very high risk
gene. If the new found gene increases your risk over the next 40
years, by 1% , thats not clinically useful test to have.
Similarly for bowel C for example. Its that bit that is not always
conveyed by the media reports.
The is the Kylie Minogue effect. She had breast C 10 years before the
AJ effect. She also had a gene mutation test , but her test was looking at
expression of a [articular gene on her C , so she could
receive a targetted treatment specific to that gene mutation.
Her gene was not inherited , it was the result of the uncontrollable
growth of her breast C . THat was a herceptin gene expression, that meant
she could be treated by herceptin , as that blocks the growth factor
on the cells and shrinks the C cells more than normal cells.
Thats what we are aiming for, targetted treatments.
The testing is easy but the interpretation can
still be difficult. The tech is ther to sequence our code, just like that,
but the problem lies in the interpretaion of the results.
There is a realistic promise there, but the practise tends not to
deliver , like the headlines would imply.
James Watson , DNA discoverer, " we used to think our destiny
was in the stars, now we know its in our genes" . Now we can sequence our
DNA we will know what our future holds. It is more complicated
than that , we do not have the crystal ball as part of this process.
We might do better to remember a quote from John F Kennedy , 30 years
earlier ," the greater our knowledge increases, the more our
ignorance unfolds". In the genomic age, that is very true.
We know more and more, we test more and more, massively more data,
but what that often does is expose what we don't know better
than before we could do that.
In the last 10 years alone a 10,000 fold increase in the speed and decrease
in the cost of genomic sequencing. In 2001 cost 3 billion dollars
and several years to sequence 1 entire genome. In 2017 you can
do that for 1000 dollars , still going down, and do several
in a day. A phenominal scale of change. People assume if you can do it
faster , you get answers quicker . But you gather a whole load of data
and lack the interpretation. |To interpret this, you need to do lots
and lots of clinical investigations, including other
family membersetc, and the overall costs can really rack-up.
An analogy is comparing fishing and trawling.
We are no longer fishing for genes that we suspect are causing
something from a family history or an appearance.
Say we have someone who has something like the appearance of
Down's Syndrome, we know what bit of the genetic code to home in on.
If you tart off , not knowing where the gene may be, trawling the
entire genetic code, you have a cost effective process than for
your single fish. But you get all sorts of fish that you don't know how to
cook, maybe poisonous , old boots, unexploded bombs, all sorts
of stuff analogous to trawling.
In the USA they are a bit more free and easy with their testing
compared to the NHS here. People pay extra money for a broader
gene test, but they don't have any answers. They find risks at most,
when they were expecting answers. Many headlines in the US,
expressing surprise from the people who pile into expensive
testing and get no answers.
The iceberg is also quite a good representation. The bit that sticks up
over the water are the people with a strong family history of C ,
or a specific set of signs or symptoms. They are more likely to have
the strong genes that give strong predictions. That family in 1895
were sticking out of the water. The vast majority is below the surface,
much less tangible you don't know where it is, the weak genes
and environmental factors that interact in a very complex way,
that give poor predictions in the clinic.
We are tackling some of this hrough the 100,000 genomed project,GP.
Its looking at the lower part of the iceberg or looking insode the
trawl net. We are focussing in on a certain group of NHS patients
that are coming through the doors anyway, that are'nt geting the
answers from curren NHS genetic tests. For those people we will
look through their entire genome , 3 billion letters of it ,
and see if we can find anything there that explains their particular
Divided into 2 groups, rare diseases and the other is Cs. The 2 are very
different. For the C patients , we sequence the genome they've inherited
,in every cell of their body and comparing that to the gene of their
particular C. The comparison will hopefully give us clues
where to target as well as how it may have arose.
In the rare diseases , there are a lot of individually rare diseases
but put them all together , then relatively common . 1 in 17
people have a rare disease. If we've exhausted the normal
testing , then comparing (the often) child's DNA
with the parents genomes, might give us important clues.
The whole project announced in 2012, took a while to get
going. A lot of investment, the plan was 100,000 genomes in
70,000 patienrs. In C studies 2 genomes from 1 patient .
13 different genome centres around the UK and several
industry partners , deliberately brought on
board to try and encourage the developement of a genomics industry.
The Chief Medical Pfficer established 3 advisory greoups to the
GP, an ethics group, science group and a data group, importanyly
they interact. I'm on the ethics group , so some intresting insights into
the ethicl discussions about this venture and testing.
4-fold aims. To create an ethical and transparent program
based on consent. This was an offer to patients , they could only
take part , if they were fully informed about the implications.
Bring benefits to patients and bring a genomic service to the NHS.
And be a first in the world to do so. A lot of genomic ventures
around the world as part of research , but within the NHS we'll be
developing this as a diagnostic tool. The hope was to stimulate
scientific discovery and medical insights by doing that
and to stimulate UK industry and investment .
Scotland is now on board as well , and Wales.
Amy has a rare disease- she will give a blood sample which is
representative of her inherited DNA, could also be a cheek swab.
Then if possible the genome from both her parents to compare it with,
to rule out normal variation. If we found something in Amy that loked
suspicious , like a missing bit or an extra bit, then we check both
parents and find one of them also has it, then the signic=ficance goes
down. Wheras if its new in Amy that is much more important.
The more we analyse our genomes , the more we realise that the
variation is much more widespread than we intitially thought.
The is a study in the USA looking at healthy octagenarians ,
analysing their code and they're finding all sorts of mutations
, bits that would predict nasty diseases and they are healthy .
Our ability to predict, from changes in the code is not as nearly as good
as we originally thought it was.
For the C patients, DNA from the normal cells , unless a blood C,
then compare to their tumour.
There are 2 routes into the GP-C . The familial Cs go into the rare disease
branch, like the 1895 family. If you have a C then you go into the
C arm, with a different type of investigation .
With more knowledge about the Cs, then the blunderbus treatments of the
past , can be refined a bit and made more targeted.
You kill of fthe C cells but kill off a lot of other celss as well,
why your hair falls out, you feel miserable . If we can target the C
cells only , then that is far preferable.
The GP project will collect medical details of the individuals
along with the genetic data. That means we cannot
anonymise this genetic information, it is identifiable.
So the data control is really important.
The sum total for the UK is now into the 20,000s , its going
well. Locally something like 2000 roughly. We've relatively few
results at the moment. This is to be expected. 3 different types of
resuls that may come out of this. The main findings are why you'vr
gone intio the project in the first place, then a bunch of additional
findings that are nothing to do with going into the project in the
fisrst place, a sort of lets offer you an MOT while looking
at your genetic code, to see if there is anything else wrong.
That was controversial as to whether it should be disclosed
automatically or whether people should be given the choice or
whether there is a choice about unknown unknowns.
Then some additional findings along the lkline of if "Amy"'s parents
were intending to have more children, then both would be checked to
see if they were carriers of a particular condition, eg cystic fibrosis,
to see if the risks to future children were increased. The controversial
bit about that, was the results would only be given , if both members
of a couple are carriers. If just 1 is a carrier then the future risk
is not increased and that result would not be disclosed.
This project is not a pure research or pure clinical
venture, a mixture. TRhe rules and regulations of both
are very different, causing no end of confusion to hybridise the 2.
The aim to get direct clinical benefits to patients is clearly a
clinical im, its fundamental to the NHS. But the aim to make
new discoveries and understandings about diseases is purely a
research aim, not what the NHS is set about to do.
To develop a genomic medicine service to the NHS is a clinical
capacity building aim and support companies and researchers to
develop new medicines , therapies and diagnostics is very much an
industry & research aim. So a lot of questions about how
someone can consent to all of these , in 1 go, in a meaningful way,
when you've simply come in for a diagnosis. Is it really ethical to
offer someone a complete genome test that might help diagnosis
when they can only take part if they agree to all of these.
An all or nothing project, sign up for all of it or none of it.
So a novel hybrid of research , clinical , service developement
, industry capacity building. Exciting but I think it also
has its problems. We are trying to target drugs to deal with
particular Cs. Say for patient" A" an ovarian C and they have a
particular DNA variation and drug A is developed to deal with htat
situation , not for anything else. Not a blunderbus treatment, focused
on that mutation. Patient "B" has a different mutation that leads to
the developement of drug B . Patient C might have a totally
different type of C or a different location but be the result of the
same mutation. So looking at the mutation rather than the clinical
picture can be helpful to know what drugs to target with.
Or the same brain tumour in 3 children , might have a different mutation
profile in each child, meanwhile 3 different tumours,in different places, in 3 differnt
children might have the same mutation profile.
We are looking at particular markers that may something about that
particular C, markers for particular drug resistance and markers
of particular side effects, they can then be stratified into different
types of patients and each gets his corresponding tablets for their
The use of genetic data and medical records is a topic of great
debate , at the moment. The scandal around the caredot data ? issue
where the govt had to backtrack pretty swiftly , about sharing
medicine info is relevant to this new venture, that wants to
gather data from the population and link that to medical records.
A rock and a hard place situation because , without that massive
sharing process , we will never know the answers.
But with that massive sharing , there are risks of privacy breaches
and how do we allow people a meaningful choice but at the same time
get everyone buying-in. People started opting out in the caredot data
situation , then the data resource is not going to be there
to be useful to future generations.
Big data is crucial to the understanding of the bit of the iceberg
below the water. So its great with a very strong genetic character that
causes a very clear clinical picture, or strong family history ,
but the more subtle interweaving different factors we've gotr to
collect data on a large scale. It may be that national is not enough
from just the NHS is not enough to get statistically significant
data , and we have to go international, and then crossing those boundaries
exposes a load more problems. So how can data sharing be developed
, retaining trust and confidence of public and participants
and that is a moral, regulatory and technological challenge, with
no easy answer.
In my group in Soton , we're looking at the people recruited to the
GP , asking them some of those questions. Through questionaires and more
detailed interviews to see what people think. Some early findings
is what the health professionals and the researchers expect patients
to say isn't necessarily what they say.
Picture of a man walking his dog alongside some water and the dog is in the water.
So should I tell him.
A nice analogy for the genetic code situation . He might know,
absolutely comfortable with the fact his dog is having a swim and knows
the dog is there. Or the dog might be struggling for life.
The issue about analysing sonmeone's genetic code , finding
something out about them , maybe relationships to other
people , raises the same sorts of questions. When you are a holder
of such info, do you tell people , or is it something they
don't need to know , something they don't want to know or want to
know everything .
All sorts of ethical and privacy questions arise , moral issues,
insurance issues and potential minefields. I run a group called
the Clinical Ethics and Law Unit at Soton . We do research focussed on the
ethical issues , raised by genetic and genomic testing and all sorts of interesting
issues about how info is shared within families .
Perhaps you might like to say something about epigenetics and the way
scientists have been humbled after they said a lot of junk DNA
does nothing, and now they find it does do something?
And the ethics of telling people, I had some 23&me test and they have a part
where you can look at it if its serious or not. I wanted to look at it
as you can always adjust your life style with the foreknowledge.?
It can be better to know and it can be worse to know.
If thr eis something you can do about it, the argument is much
stronger. A treatment, an intervention, a lifestyle adjustment
that may change that. There ae bits of your genetic code thay might tell
you are at risk of something , that you can do absolutely nothing
about. It may never eventuate anyway. 23&me does alzheimer
gene testing and at the moment there is no treatment for that.
It might give you the opportunity to say yes or no about finding
out. But when a number of members of a family do that test,
then you have to tnink about other peple finding out.
Were you only testing people who cane to the hospital
or from the general public, as I put my name downcfor it
and never heard anything about the GP.?
Its not the general public , its people with particular
Does it give a bias, that way?
The aim is not to look at the whole population , lets look at the
low hanging fruit, if you like. If we look at the whole population,
we will find a lot of gnetic variation , interesting, but here we're
trying to find new diagnoses.
Epigenetics and junk DNA?
Epigenetics are things that affct the expression of your
genes , without changing your code. So sommething
binding to your code , alters the regulation of a gene, that
is farther down. It might be something sticking to your code
and silences a gene or makes it over-active.
Epigenics is often propogated across the generations ,
such that if you inherit a particular sequence from your mum
, it behaves differently if you inherited it from your
father. The exact sequence might br the same but because of diffeerent
things binding to it, that we cannot stil ltest in a whole genome test,
it will behave differently. There is a rich and emerging study of that.
Originally the GP was to collect what was called other-omic sam[les,
but in practise it has been too difficult to do, its still an aim
, but not happening routinely at the moment.
Junk DNA was a term used 20 or 30years ago , genes send the
messages , when genes go wrong , the message goes wrong - nice
and clear cut. The bit in the middle doesn't do anything , actually we
now know that the bits in the middle are often important agin
in regulating things if something is bound to them . You might get a
promoter of a gene or a silencer of a gene, thousands of letters away
from the gene itself. Only now are we finding what and how it does.
There must be bits of DNA in me that are silent, never do anythiong
but in someone else wil ldo something. Junk DNAd oes exist
, just much less clearly delineated than we originally thought.
That swhere the JFK quote comes in nicely.
The very basics. I'm assuming that C starts from 1 errant cell
but can I also assume that happens quite often but never develops to
2 cell or 4 cell , so epigenetics can come into play in that
early stage. ?
By definition its not a C then, it is not growing uncontrollably.
The pre-Cs may go away by themselves . For example a very coomon
ductal carcenoma in-situ in a woman's breast will , we think,
often regress by itself. But now we are better at screening
for things , its a rare surgeon , who would leave that untreated,
because it might go on to be a full blown C and spread to other parts
of the body. You've got protective factors , control mechanisms
that , may allow things to wrong for a little bit and tyhen
kicks in, and retains control again. THe immune system is vry
important there. The more we learn about it , the more we
realise some of those stop checks and signal is your own body
recognising that the cells have changes so much
, that it looks like its infected, and so needs attacking. A good control
mechanism that needs getting on top of.
So young kids or teenagers , they all could potentially have a C
any day , a number of times a year, but it never develops.?
Yes. If youve inherited a mutation , that just starts you off at a
disadvantage. You may not even with a really strong BRACA1 mutation
you may have enough protective factors around , to never develop
Typically how many point mutations does it take to get to
, presumably on some occassions just 1 critical mutation might.?
In the classical types of C, 1 mutation , such as described by Nudson?
a retinal blastoma , a childhood tumour where you're born with 1
mutation and just waiting for the othe rone to hit , and the same copy
of the gene , so both of your genes are knocked out and you develop
a tumour at the back of the eye. So inherited 1 , that alone isn't enough
and the second 1 is a chance one. In say the case of bowel C,
people don't know what typically is, but 4 or 5 is usual.
It depends where they happen, just drinking our pint of
beer we might be knocking off a few, starting a few
mutations off, but its the critical bits of the DNA
if they happen, then you need far less hits than if non critical bits.
So you're saying , a single point mutation can't give you a C,
unless you already have one?
I just don't know, I don't think that study has been done.
I think its pretty unlikely that 1 point mutation
would be sufficient because you still have another copy of that
particular gene, that is knocked out.
That depends on the bodies physiology, being able to say we won't
use that one, we'll start using that one?
Thats part of the deal of your bodies physiology, it does
that, yes. Again it does depend on the gene, but for most of them,
the point of having the other one, it can compensate.
Sometimes you're right one gene is so bad ,it overwrites
the good copy, but that is not the usual mechanism for C.
When I looked at mine, some things can balance out. I had
haemiacromatis ? where the body takes in too much iron
and the other was a type of mild leucaemia, another one was
thrombosis , a lot to do with the blood.?
The 23&me originally started as looking at your ancestry ,
how much of a neanderthal you were , block background.
Then it started looking at common variations and those genes
subtle risk factors , they are nt high risk predisposing genes.
Nothing in 23&me apart from looking at some Jewish
mutations for breast C, all the rest are subtle risk
factors, that don't do very much. The problem is, if you have
an over the counter test, to tell you a lot of medical info ,
it can only go so far. Thats where it came into problems with USA
,the FDA first said we don't want you doiung any health
related testing, because we think that should be handled by the healthcare
system. just recently its been approved again, but I would urge
caution. Because they're selling point is knowledge is power,
an easy slogan to buy into , but power to do what?
Its all very well, doesn't cost much , probably not going to harm
you , but will it benefit you much.
They came up with Alzheimers, Parkinsons BRAC1 & 2, so i'm
watchong my diet and it does make me research internet things that
are happening in those areas , like anti-malarial drugs against
Of the people consulted for the project what proportion
decided not to sign up to it?
Very few people said, I'm not signing up for that. The question is
are we in some way coercing people to take part.
They are people who have come throught the health service
, not the general publinc interested in finding out. They are ill
or an ill person in their family and they want a diagnosis
and this a way to a diagnosis. But at the same time they have to
sign up to all the other bits. But have we twisted their arms into taking part
, when under totally neutral circumstances , they would not have joined.
A few have said the whole data-stuff is too much for me . There are quite
a lot of people who don't turn up for their appointments, so they
might be voting with their feet. But of those they usually do rearrange
for another appointmet. Of the people suspected of C,
across the board , pretty much everyone says yes. A lot say they go
ahead becaus eit will help advance knowledge. You're not going to say to a
C person, this test is going to revolutionise your particular treatment
or diagnosis , its mor efor the future. The rare disease arm , including
familial Cs , its much more sold to people as a potential
diagnosis , that they won;t get throgh the health service.
If someone has developed C ,brought about by smoking,
would he be invited to the study?
Probably not. There are very specific recruitment criteria,
that have broadened a bit after realising how difficult it was
to get people to take part. But we as health professionals
, finding the right people, in the right ciircumstances .
We are looking fo r people t o offer it to , rather than
those we are forgettingto recruit. Its probably true that the people
focused on this project , recruit people to it, wheras
a jobbing GP or non genetics medic might not thionk
about that. eg psychiatrists , certain psychiatric conditions are
elligible to be recruited, but I'm not sure there is much flow
from psychiatry into this project at the momet.
Do the medico/genetic R&D companies , do they get
access to biopsy samples , to try their medicines on or do they
get potentially nice compliant guinea-pigs to try their
At the moment the GP is organised like a reference library. You can go in
, read the book , but you cant take the book out. That is to reassure
people, they don't have access to the patient to inject them with all
sorts of drugs, just to look at their genetic code and perhaps just the
results from biopsy samples, so they never get biological samples.
The gut genome seems to be coming influential/fashionable. ?
We don't have the evidence yet to see how influential, certainly
lots of headlines. It is promising but not influential right yet,
as we don't yet know what it could influence.
That is looking at your microbiome , your gut flora .
Again it seems a bit like junkDNA , as we used to think.
What you shit out is out of your body and now irrelevant,
but it turns out , its important what the balance of the bacteria
in there is. There is nothing in pour body that is straightforward,
and working in isolation. Its a subtle set of checks and balances,
and very rare that you can dsay , this factor will cause that definitely.
That factor in conjunction with other unknown factors might increase
Perhaps a quantum computer will be able to sort it all out?
Thats what people think, in the more data they get, the more likely
we will get an answer . But i suspect a lot of these things will not be
amenable to computer power, so many variable factors like the
environment in your mother's womb, where you lived,
your particular mix of racial ancestry, diet as a child , the food
you had yesterdy.
Genetics and the environment, you touched on , but much research there?
How you document people's exact environment , unless they are
strong influences. Look at smoking and how long it took us to
make the connection between smoking and lung C.
A strong risk factor, imagine a risk factor much more subtle , identify
when its a risk factor and when its not but is protective factor.
We're now in bigdata world, and large cohort studies over the
years, I wondered if that could be tied into the gentics?
I don't know about better but in combination , cohort studies ar e
very important. There are lots of moves to do genomic analysis
of cohort studies, definetly. A lot has been written about the
difficulties of just say a prope food intake diary, and make that
reliable. Cohort data is probably the best stab at the moment,
but its still easier to find the big strong factors than the subtle ones.
We tend to forget that genetic factors can do 2 things, they can
say increase the risks of C, but on the other hand they can
decrease your chances of something else entirely. How do we
balance al lthose things out. We often see it in families where
they've inherited something that sounds really awful , why
has evolution not got rid of this, probably because its also
protecting from something else.
Could you explain what cohort studies are?
A posh word for following up people or families , over a long
period of time. Rather than saying we'll take 100,000 people ,
and analysing their genome. Like the Southampton Women's study ,
following women, as they have children, then 5 years later,
10 years later.
The POSH study is a breast C study , the age of diagnosis
and their genetic code, is not a cohort study.
It can be a very specific cohort , just people with osteoporosis
study . We're watching that specific population to see what
happens in their futures. So a statistical analysis ,
when you've collected the cohort. It could be people
born on a particular day in 1958 ,then follow onwards.
Some of those are still going strong . I think setting them up
now is much more difficult , people worry more about
the privacy, data protection etc.
The dietary studies are funny because the ask like, what were
you eating 5 years ago?
You just don't know.
And you don't even know what they were putting in food 5
years ago, put it under a different name even?
Also what we cooked our food in, say aluminium pans,
the chances are we absorbed Al which may be very
bad for our health. But its more likely you will
take in Al if you cook acid food . Factors like that will
interact with your genes. So we could think of a particular toxin ,
get 10 people to eat that toxin, and some people it won't
affect at all because somethong in their genetic code that
protects them from it, or it does not do the same genetic
Like sickle-cell anaemia and malaria, protects in the carrier
state against malaria.
There was a major public health incident in Camelford , Cornwall
wher e a lot of people took in a seriously abnormal amount
of some sulphate in the drinking water. At autopsies later
on , illustrated that. Would a follow up study of that
population have been a cohort study?
Cohort is just a longitudinal look at , rather than a cross-sectional
look out. If you followed them over time that would be a
cohort study. It is a fairly loosely used term.
You can go in and study 100 people, thats just doing a test.
If you follow 100 people , however you might have selected them,
then that constitutes a cohort.
Then there are people who come in from another area and
mix up the gene pool again. If that is not taken into consideration,
how fare your results?
For example thw Asian population coming to the UK, their incidence
of certain diseases change quite dramatically. So we thought that must
be due to environment, it can't be genetics. But its still
a combination of the 2. Nothing is ever just genetics or just
environmental, maybe the majority to one side or the other, but
always a mix.
But you can get a prevalence of a disease gene mutation in Ireland ,
Sweden and Japan but they are all geographically separate?
If you look at smoking, we will all of heard my grandad smoked 60
a day for 60 years and he only got C whan he stopped smoking,
or he never got C. There will always be people who can do some bad thing like
smoking and get away with it. Probably because there is something in
their genetic code that protects them from the damaging effects that
get to other people.
There are about 300 different things in cigarettes?
You talked of the study of healthy octogenarians , who had gene
faults but never materialised into anything. Are you concerned that
with the advent of genomic medicine becoming cheaper and quicker,
do you think there is a risk or danger of premptive or preventative
surgeries or treatments, might happen to people that would never
need such interventions?
Yes. Thats where the fishing v trawling comes in. Styart off with a very
strong family history, then you find a mutation ,then its a pretty
good bit of advice , think about risk-reducing surgery for example.
But if you start by analysing the genome, and finding an alteration ,
then the data coming in now shows that they're ina different
boat but they feel themselves to be in the same boat.
A woman with a BRAC1 mutation from a sequencing but without
a family history , might think she has the Angelina Jolie gene,
but the evidence seems to suggest that that woman's chance of
developing breast C is much much lower , than someone who
comes with a strong family history, because she has other
factors that protect against it. So doing screening for the whole
population , then having your breasts or ovaries remoived is
going to be the wrong advice . Its such an important point and we've
not got there yet. The business of additional findings from the GP
, people coming in with a child with learning difficulties , offered a
BRACA test , as a by-the-way freebe, those women may not go on to
develop breast C , but if she gets that result and then feel as being
in the Angelina Jolie boat, they are likely to seek that sort of
intervention. I'm worried about that.
Do you think there are enough safegaurds in place?
No I don't , not at all. Hopefully we will get there as mor estudies
come out . Its now been calculated that we each have 5
serious mutations in our individual genetic codes, that won't
cause many of us , any problems at all. As that becomes more widely
known I think we will be more cautious. People tend to think
of the genetic code as a blueprint , that once we have the readout ,
we'll know wha tto do with it. But you need the readout , with the
family history and signs and symptoms , to interpret it.
Those 2 really need to go together , that is the thing that is not
widely understood. That message is one of the key messages
we ned to try and got out there more.
As far as your ethics panel. Thinking of the Angelina Jolie
case of breasts and ovaries removed and now her marriage
has broken down. Not necessarily related , but there
could be psyschological factors coming in .?
We shouldn't go there .
For anyone , at an every day level, its a big responsibility , as their
lives are being altered?
And also on the level , people tending to think , that having a breast removed
as just a boob job, 10 a penny. But having your breasts removed
, as risk-reducing surgery , has about a 30% complication rate ,
and people don't quite hear that bit, they just want rid of them.
You don't know what other hormone effects there may be for the
rest of the body. You cant have a total
clear-out , there will always be a bit of your body that is at risk
and you cant remove it all.
Is there any effort to educate the public as a lot of this
is about expectations, and not really from knowledge?
Things like this talk is something like we should be doing more of.
We must not sit in our labs or ivory towers just saying this.
We need to go out to engage the public . I think the group
behind the GP , Genomics England , they have tried hard to engage
more . There is criticisms of them - a great big juggernaut ,
moving in a clumsy way . Its a bit conflicted as on one side
it wants to recruit lots of people , sell its wares and at the same time
urge caution ,an uncomfortable mix. The story we get about
genetics from the headlines is not realistic, we need to find other
ways to get that story more realistic. The hype about gentics has
not died down. Usually with a new medical developement , a lot of
hype and then it dies down. The reason behind the genetics hype is because the
technology has kept on faster and we will get the answer with teh
ext bit of kit . There is something about genetics that is different I
23&me they ask a lot of preliminary questions and then feed back to you
those questions and replies as answers.
A number of studies into those direct to consumers companies .
If you send the same DNA sample to different companies you
get different results back.
Worse than that, if you send same samples to different companies along
with a description to one as being a young fit woman , and the
other as an overweight elederly woman , you get very different
results back , as they use that , to make their predictions.
Monday 08 May , Dr Thomas Kluyver, Soton Uni : The Southampton Sailing Robot Project
26 people , 1.5hr
I was asked to get involved with a robotic sailing project as I'd done a bit of
sailing and I liked fiddling with computers. 9 months after that I was on the
way to Satanstead airport , to fly to Portugal for the World Robotic
Sailing Championship , 2016, a whole lot of fun.
With me tonight are Tony and Sim who were also part of the team,
and a number of other people , 9 in total and 7 of us
went to Portugal. Of the 9 in our team , all were of different
The first thing you need is a boat. We initially thought we'd build a boat,
but that is difficult and time-consuming. There is a community who
do remote control sailing , including a class called the 1m class,
1m long . Plenty of these already made and we bought a secod-hand one,
for something like 200GBp. There are 3 sets of sails, for different
wind conditions, smallest for strongest wind and smallest for weak winds.
Nice thing about an r/c sailing boat , it already has the servo motors
to move sails and rudder , a chunk of the work already
done for us. So the bits are radio receiver with aerial , about an inch long.
2 servos, the one with the large round bit is the sail servo, pulling the sail
in to the boat centre , then a more standard servo that turns the rudder.
Then you need a computer to control the robots. So a Raspberry Pi,
a tiny computer 2x3 inches with processor , memory plus a removable
memory card for the programs. You can connect it up to a
network , no screen or keyboard but once its connected
to a network we can talk to it from standard computers, move the
programs onto it, get data off it, tell it what to do next.
A lot of exposed electronics, which don't mix with water
, especially salt water where the competion is held. So Tupperware
boxes to keep most of the water out of it. Wires through holes made in the
box to the servos and sensors, holes sealed with gummy stuff.
We roughly cut a large hole in the hull side , so we could
slot the computer inside . When sailing the joins to that panel
covered in tape , as waterproofing. And more tape over
other places where water could get in. The brain of the operation got
called Brian. The boat is called the Black Python , like the
Pirates of the Caribean , Black Pearl, but the computer language we use
For the sensors we made one from an off the shelf windvane, glued to
2 ring shaped magnets to it, coupled to a board that senses magnetic fields
so we can detect what orientation the magnets are in , and so which
direction the wind is blowing across the boat. Mounted on the
top of the mast about 2m obove the deck, to avoid the sensed wind being distorted by the
sails. Under the hull is a weighty blade like keel to counterbalance the
lean from wind pressure on the sails ,across the hull.
We need a GPS . Al lthe competion challenges require negotiating
around marker bouys that we are given
GPS co-ordinates, Lat and Long. The boat needs to know where it is
, to go to where it needs to go. This GPS is also on the mast,
about 2 inches long , this one otherwise used for high altitude
ballooning , apparently that type works well for this sort of app.
Cost is only something like 7 or 8 GBP.
A compass to show which way the boat is pointing, an accelerometer
to tell if the boat is leaning and you need that to adjust the compass,
a board about an inch square, MEMS micro-electro-mechanical sensors.
A way to get physical data into a form that can be electronically
processed. We have to calibrate the compass for each use, 2 people
holding the boat and turning it in a circle, the calibration dance.
Now how do we put the bits together and make it sail.
Why is this an interseting challenge, why difficult for a robot.
There are othe rchallenges where the boat has motors, there is a Soton
team called hydro-team , boats with motors. So the control to go
from A to B is pretty straightforward. Point it in hte right
direction and tell it to go.
For sailing , it is dependent on the wind direction , it can't go
straight into the wind, 90 degrees to the wind or have it behind
and modern boats can go 45 deg to the wind. A better boat will
let you go closer to the wind. You have to zig-zag to go into the
wind, tacking. 45 deg to the wind one way , go about 90 deg
across the wind and sail on the opposite tack .
Eventually you get where you need to go. This is where control
of the sail position comes in . Running in front of the wind,
you can let the sail out as far as it will go , near enough. It acts
as a big bag, like Viking long ships with a big square sail .
These boats go fastest at about 90 deg to the wind by
putting the sails at about 45 deg, then the sail is acting like an
aerofoil , like the wing of a plane. The wind is perturbed around the
curves and pushes the boat forwards efficiently.
If you want to sail close to the wind , you pull the sail closer in ,
it will keep you going forwards. This is partly the function of the keel .
If going across the wind , you don't want to drift in the direction of the
wind, sideways. The keel blade helps to keep you straight.
We did most of our tests at Eastleigh Lakes near the airport.
We also borrowed anothe rboat , to test out our control
systems before our competition boat was ready. That boat was
simpler with 1 sail, our main boat has 2, mainsail and jib.
Some boats the sails are controlled separately but our boat
, the 2 sails are controlled from 1 servo, they move together.
There is asome ability to adjust them separately
, for when we set-up the boat , we can adjust where the sheets are
connected . Once its on the water they go togehter.
We ended up with 2 borrowed r/c Lasers and we could test the
r/c on one and the control systems on the other.
A big pole has a wifi antenna on the top so it gets us
better range and stay in contact with the boat during
testing. Requiring keeping rain and sun off the control
laptop. The antenna is very directional , requiring it
being pointed to the boat , which can get a bit tedious.
During the competition , this kind of contact was intermittant
, we were trying to keep a wifi connection from the bank
but the challenge area was several 100m away from us
and a dodgey connection. But the boat does not actually
need the wifi connection , it was just for us to know what
was going on onboard. Once we set it going its then totally
autonomous. We have the original r/c system still in place as an
override. Also , in the competition, you are allowed someone in a chase
boat who could intervene if things go wrong, like crashing into something ,
other than tht you have to let it do its own thing.
We used open source stuff for the Pi, the Python language our source
code in GitHub, a www repository of it contains all our code ,
and you can see what we're doing wrong. The key component,
to make it work is ROS, the Robot Operating System, the version
we used was Indigo Turtle with ? shell . ROS principle is there
are nodes which are separate programs , running things, and they
talk to each other. One program just controls the servo motor,
one that just gets data from the wind sensor, they send out ROS
messages which the other programs can listen to . It makes it easier
to separate out the bits needed for the robot, so if the compass bit crashes then
ROS knows how to restart that , so it does not mean everything has crashed,
just that one part has crashed. A lot of people program robots and end
up re-writing everything from scratch, so ROS means you have
pre-written bits which can be shared between multiple robots
. So if we've written something that works particularly well, say
determining how to tack up-wind, then someone else could use that and
plug it in to their own sensors and things, which might use data in a different
format. But a standardised interface that lets you take and combine
different bits of code.
Q: With the sail servo , do you have a position sensor for sensing the
At present we only know how much sheet there is in or out.
So if the servo drives to one extreme, you don't know about that until
other things start happening?
Yes, the wind sensor we can see which way the wind is coming from
but in the edge cases , where you jibe, then you don't know exactly
how the sail is set.
ROS lets you define the launch file , which tells all the nodes that
we want to start. There are different launch files for testing of
calibration of sensors and then for actual sailing in ernest.
There are parameter files , containing settings for different sets
of sails , for different courses . The co-ordinates we want to go to
are programmed in , via the parameter files . ROS makes
easy ,the monitoring and the analysis. Al lvery well putting the
boat in the water and try nd make it work , but often when
you are sailing , there is no time to work out what is going
wrong. Without that, when you get the boat back , you would
not have the details of during the error performance,
you would then only have the memory contens of the boat
turning round in weird circles and would then hacve
to try and piece together , what the system was doing that
made that happen. ROS has a bunch of useful stuff to
give you more info about what the boat was doing , centred around the
tech calles ROS-Bag ? a way of recording all the messages of the
different parts of the boat are saying to each other , wind is 20deg, compass is
170deg at a particular moment, all recorded on the Pi .
Then we get the boat back , we can pull that data off and plug it
into various things to analyse it, tools like ARCU2? that can show us plots
of angles over time , a map of where the boat is, relative to markers
for the course. We also wrote our own stuff to help with theis ,
an HTML dashboard , a live view of what was going on the boat, on
computer or a phone. This was helpfull a couple of times in the
challenges, people in the chase boat could pull out their smart phone
, connect to the boats wifi , and view some of the key parameters from thr
boat. We also wrote a set of ROS nodes for simulating what the boat was
doing , so we could test the boat code without having to place it
on water every time. The nodes for the boat itself take the inputs
of where the boat is, what the wind is doing, and polls? output of what the
boat should do now. The simulation nodes can complete the circle.
Take the input of what the boat wants to do now , and then update the
posistion and heading of the boat. In the simulation we make the wind non constant , as happens a lot in reality , which makes sailing so much more
confusing than the simple diagrams of wind just from one direction,
A map view video of the waypoints the boat was going through, from the
recording of Rosbag messages along with other data to work out what the
boat was doing at that point, why it was nit doing what we expected
it to do. Sept 2016 in Viana del Costelo ? in north Portugal.
The River Lima? with a bridge designed by the designer of the
Eifel Tower. We launched from the bankside. There were 12 teams ,
2 classes ours was in the micro-sailboat class which is up to
1.5m long, 7 teams in our class, 5 teams in bigger boats up to 5m
tending to be from Spain and Portugal as large boats.
The competition has been going for a number of years, moving
each year. 2015 it was ? islands between Finland and Sweden
and 2017 will be in Norway I think. Theya ske dus if we'd like to
host it in 2017 but we felt we could not arrange that in time.
There are no physical bouys to collide with and we have no
collision detection on board. In the first day they all
sail together . You are allowed momentarily to take control
via r/c to avoid a crash. 5 days of sailing, the first day was for testing,
getting used to local conditions. We discovered that waterproofing is
difficult, electronics and saltwater don't mix well.
The part that switches between automatic control
and the r/c , liuckily we brought 2 of those as the first got
destroyed by saltwater . We aquired some sanitary towels in
Portugal to soak up excess water in the hull, which worked well incidently.
The box duct-tped to the outside of the hull , that contains the
competition's own GPS tracker, for a separate log of the boat
track, so they can score the competition.
The first race was to go round 4 marker s , the quickest to go round
al l4 , would get the highest score. Not for us though.
The second day was station marking, just 1 marker and stay as close
to the marker as possible for 5 minutes. This sounds easy on land
but whan sailing there is no stop for a sailing boat, always blown by
the wind and pushed by the current . THere was a very strong current in this river, we found on the test day. You have to keep moving to stay in
one place, like Alice in Wonderland.
Q: Any detection for current?
No , the boat judges where it should be going and judge it by that.
Q: you don't get it via the gPS system?
You can try and work out I'm not going where I think i'm
going . We did not do that as a lot of other things to do, but you could
in theory pick up some measure of the tide via the GPS.
The third day was a grid search an L-shaped grid of 27 boxes
and we had to get into as many of the boxes as possible.
The fourth day was a collision avoidance day, going back and forth
along a narrow course ajd at some point they towed a line of
big orange buoys across the middle of the course.
The boat had to detect these , swerve round them , then return
to course and continue.
By the 5th race everyone had by now discovered the current is
really strong . At the start the wind was going one way
with the current as well , so very challenging .
Of the 12 boats in that competition 2 boats managed to start
the race and one boat managed to finish .
The boat that started made it past 2 markers but failed to
turn at the third. Our boat was not at all successful.
Partly due to the current . 2 servo motors, one controllint the
sail , one the rudder and on this day we managed to plug the
rudder servo into the sail servo system and vice-versa.
We had a boat that went round and round in beautiful circles ,
wiht a lot of exasperated humands on the bank.
That was something you have no hope of diagnosing from the
computer logs, because the boat is doing everything as it should,
its entirely a hardware problem. As a result of that, we added
some code, so when we start the boat, it wiggles the rudder in a distinctive
pattern and then puts out the sail a few seconds and then all
the way in for a few seconds. We never made that mistake again, but we
did make other mistakes.
A whiteboard i nthe clubhouse with co-ordinates written
on it, lat and longitude. Most of the other boats did much like we did,
lucky for us in the overall scoring. An amazing GPS log of the French boat
that managed to finnish, because it did very tight zigzags all
the way up a few hundred metres up one side, about 1/2 hour ,
then zoomed around the rest of the course.
Day 2 , staying on station, that part of Portugal gets sudden
fogs that turn up from the river. A new meaning for getting data out of the
cloud. We were sitting on the bank, numbers coming in , but we could not
see the boat at all. For the first minute stay in one small circle around the
point and then 5 minutes staying within a circle that contains 95%
of the track. Fiddly to work out, but done by computer.
We managed to get a 25.3m radius , could enough for second place in that
challenge. THe welsh team won that challenge, staying within a 5m radius.
Day 3 , getting into the most squares, we managed a fair few of the
squares and again good enough for second place, the Spanish
team did the best there. We discovered its not a good idea to use the
launch file from yesterday , as it started off in a loop
to where it had been doing the position keeping , the
day before. The large squares were 60x60m divided into 10m
squares. Luckily they allowed us a second go, after our boat
sailed off in the wrong direction, otherwise it would have
been nul point for that.
Day 4 , obstacle avoidance. We got a USB webcam , same as
simple skiping one. Fitted it to the bow, cable running back
to the boat computer . We could look at the bouys beforehand
, so we knew what they would look like. We wrote a simple bit
of computer vision code , that basically just counted how
many pixels were orange. So we had to define the range of
colours for that orange. Then we had to decide the minimum number of
orange pixels before it decided to avoid. For the camera we had brought,
was not suited to outdoors bright Portugese sun , getting very
washed out pics from it, the solution was a trip to a supermarket
for some cheap sunglasses , popped out a lens and selotaped it
over the lens. It worked. The camera was put in a plastic bag to
keep the water off.
It sailed back and forth along 150m course, they towed the bouys into the
path of our boat . We were sitting on the bank, watching the
dashboard , a figure saying not detected, repeating , then just about
as we were to hit the buoy , detected , but unfortunately too late
to swerve out of the way . The proportion of the image , to be
orange , may have been set too high . Also they had told us the
buoys would be in the middle 50m section of the 150m course,
according to their GPS they did , but according to our
GPS the bouys were to one end of the course. Our boat had
just left the area we had set for it to decide whether or not to
swerve. We collided with a buoy. This may not seem good but it
was good enough for us to get first place in that challenge.
As the course was very long and narrow, none of the
other boats managed to stay in the course. It may have been pure luck
that our spot was just as the tide was at low tide and the current was not
pushing the boat.
Q: Perhaps you should have collision avoidance for all times.?
We have to go round bouys at other times and we did not want them
detected by that ststem then. Perhaps we should have made the
observation area more generous. GPS is very consitent with the
same unit but there was questionable GPS reading between our GPS
reading and their GPS reading. After all that we managed to get a win
in our class. If you did not managae a valid run on a given day you got
8 points, 7 boats in a class plus1. First place gets 1 point
, second 2 and so on and the lowest score wins. So getting 3 valid
entries we managed to come in first over all, which we all
were surprised by, as none of us had done this sort of comp[etion
before. We learned a lot doing this, had a lot of fun .
My take-away from this is , reliability beats performance.
That your boat works is better to focus on , than make it work well.
It did not do any of the challenges brilliantly, but it do
all those challenges, which was a lot of the scoring.
Lots of really simple things can go wrong, plug the wrong thing into the
wrong thing, you can use the wrong file misdirecting it, water getting in
because you've not sealed it well enough. We had one day when the boat
was doing something funny, the chase boat went after it , to pick it
out of the water and it was noticeably heavier because it was full of water.
This was a spare time project for all of us, we all work on other things
at the uni. My work is software, programming stuff and this project
brought home to me how challenging it is doing hardware stuff.
A whole new array of things that can go wrong when dealing with
hardware, that otherwise a computer deals with .
We will be doing it again , we returned the boat to the water for the
first time since the competition only a few weeks ago
with lots of ideas on how to make it go better.
Are you using the heel sensor data for anything?
It does get published but its not of much direct use. It does get used
in the same nodes that publish it, because the compass data
Do you have any plans for optimising for the wave condsitions?
Its not something we've done anything with yet, something we wish to
investigate more. Particulrly in choppy waves , a sa small boat
doesn't have much momentum it finds it difficult to tack.
As soon as it turns into the wind it looses momentum , loses
steerage. So we have some ideas for optimising by tacking on
the down slope of the waves.
I was thinking of sailing freer, sails farther out and lower? , to pick up speed before tacking?
We've not thought about that. Making the boat longer would help with this.
A physical solutiion to this sort of problem is often better than
some smart algorithm.
If you truly roboticed it , you'd do as a human would do and
you'd set the sails farther out , to pick up speed, so the VMG?
would be the same possibly as going furthe r, off the wind. This
happens in small human crewed boats?
We don't have very accurate velocities, just based on the GPS.
So we need a way to integrate the GPS sensor to something
loike accelerometers, to work out accurate velocity feedback.
Then that would be possible, a good idea. How to tell if the
sea is choppy or not , maybe a camera system, certainly anothe r
sensor required. THen experimenting between human observations
and trial runs to find correlations.
Do you have different sets of polar diagrams for different
sets of conditions?
When your tacking up wind , how do you decide on lots of short tacks
or longer tacks, based on how far you are waway from your straight line
course, or set distances maybe?
The initial thinking was to detect the ley lines. This is where we
found the changing wind direction makes it trickey. The wind changes
and the boat thinks the ley lines have swung out 90 degrees, so we have
some code that tries to average the wind direction. As we get closer to the
waypoint we are trying to go to, we have a thing called tackvoting?
cuts in , so rathe rthan considering am I past the ley line at this moment
it keeps a 10 second rolling count , sampled every 1/10 second, did I
think I was over the ley line and ready to turn. Once that number
hits 75 then it will turn , which has the nice side effect
then once its doing that, then it wont turn more often than every
7.5 seconds , because you want some gap betweeen your tacks,
to let it build up a bit of speed.
Do you know the French boat did this, lots of little tacks?
They were using a vector-field approach , a vector flow approach. They set
up some kind of virtual obstacle and a point of attraction ,
and between those you can work out optimum fields, and point out the
direction you want to sail. Hence that team doing lots of small
tacks all the way round, artificial potential theory, well accepted in general
robotics control) gives that.
The french boat was in a different class , about 1.6m long ,
super light , which means it can easily tack in difficult
situations. The net effect was their boat stuck much closer to
the line betweeen waypoints.
Do you have a sensor for how much the boat heels over?
Yes, from the accelerometers , sensing gravity. At the moment its
only used to corrdct the compass.
Are you allowd a second remote sensing sytem , in the water to
detect tidal current and transmit that to the boat?
I don't think in the rules there is outlawed remote sensors on the
shore or whatever. I don't think any team are doing that.
We did not have a reliable radio link either.
Could you use a parabolic dish rather than the usual wifi thing?
I don't kow what the internal geometry inside the white box , it
is long range and highl;y directional , but the range was not enough
For your servo systems do you have something more subtle
than the normal proportional control, a suck it and see a marginal
shift , to test out and then back off , someting more sophisticated
as you have a computer on board?
No, the servo control is the standard pulse-width modulation .
One thing we've been thinking about is , a human sailor will
look a tthe sail and if he sees it fluttering , you need to pull
in a bit more . Could we have a vibration sensor mounted
on the sail itself , also measuring the tension in the sheet .
So you are sailing at a specific angle to a relative wind rather
than looking for the point of flapping/luffing point. So sailing at
a conservative 45 degrees say instead?
At the moment just a hard coated? angle , a hard-coated table
of if the relative wind is 90 degree then the sail angle is x
and it adjusts within the angles it knows about.
Did you ever get involved with strategies of stealing other boats
wind or that sort of thing?
No ther ewas 1 day of compete racing scheduled, all
tyhe other challenges were individual boats at a time.
Even at the fleet race, no one was at the point of being
capable of stealing anothe rboats wind, just going in the
right direction was quite enough.
Is it the same challenges each year?
Similar each year but not the same. The organisers a the site get to
organise what the challenges are. The computer vision challenge
with bouys was new last year, replacing a challenge from
the previous year that involved collecting data from added sensors
on the boat.
You know aboout the challenges before the event?
Yes, we could practise them beforehand.
So you would know in advance they would be orange bouys?
We could do calibration with the Go-pro with real
objects on the water a tthe site, to check our coding
recognoises the object.
How many algorithms have you got running?
Each line with a node is one bit running, so 15
to 20 things running .
That is the tasks, but the algorithms to interact , data from
multiple sensors , an algorithm to manage that?
Each sensor has its own thing pulling the data from it, there is
really only one core algorithm that is deciding where to go next
So one algorithm taking all the dat ain and deciding how to
set the sails at any 1 point in time?
Yes, try to go in this heading and the sail control
goes separately, keeping track of the relative wind.
Its smart enough to know it cant go directly into the wind
and different tasks that can switch in, what should the boat be
doing now . A different bit of code for the obstacle
avoidance for example.
They always choose tidal rivers and not nice quiet reservoirs?
The previos year it was in the Baltic Sea,next year will
be in Norway presumably a fiord.
If you don't use the heeling sensor , could you not turn it
90 degrees and use it as a pitching sensor. ?
The accelerometer is 3-axis so we have pitch as well. So pitch
and roll off that , not yaw. It gives 3 acceleration readings and
we convert that to pitch and roll.
How long did you spend on the project?
We started in Jan 2016 and the competition was in Sept.
We had meetings 1 evening a week and occassional weekend day
of working on it or testing it.
Apart from being a bit of fun , is there anything to be learnt
for sailing in general.?
A challenge called Microtransit , a boat smaller than 2.4m
, must be wind-powered to sail from the UK to the USA .
Loads of people try it every year , but no successes yet.
If we got a boat like 2.4m , what can we di with it. We can
collect environmental data , monitor sea levels, check
water quality and waves across the atlantic. Wind energy
is virtually unlimited , no fossil fuel consumed.
We're not advancing humanity at the present stage bu tin
the longer term, we open source all the projects, to anybody
interested . We could monitor fish populations, water quality , that
sort of thing. It would be interesting and cost effective.
All our kit costs are second hand boat about 200 quid and all the
electronics add up to no more than 100, the Raspberry Pi
at 30 quid is hte most expensive bit, all hobbiest sort of stuff.
Are you satisfied with the data from entry-level kit?
We've stared with envy at a much higher quality
accelerometer on display at Ocean Business at the NOC
recently. All sorts of hitec gizmos. A lot of the stuff we are happy
with . We are currently trying to integrate the GPS
and accelerometer so we have a speed reading.
Do all the teams share their data and ideas?, perhaps
binocular or sonar for instance?
One team was doing a sonar thing, not underwater but
ultrasonic in air . Sonar under water there is so many
reflections . Most teams were like us with a camera on the
Do the rules permit wing-masts and hydrofoils?
I think the rule was anything as long as it was powered by the wind.
A wing-mast might be simpler to control than a pair of sails,
a double-sided sail wrapped around the mast?
A couple of teams did wing-sails, so allowed.
A Flechner Rotor type thing that required mechanical power to
rotate the rotor , to then grab wind energy, would not be allowed?
You're allowed a linkage from a wind-capturing something like a
propellor, as long as the only source of motive power is the wind.
Have you any contacts with the big-boy autonomous , huge trading/cargo
sailing ships that are just coming off the drawing boards, multi-mast and
huge sail arrays but just 1 human on board ? Wherever there is reliable
trade winds around the world.?
We must share something in common, in the way of the control
systems , but have no direct contact.
You've not found any use in conformal coatings over the electronic
gizmo boards, just waterproof boxes?
We did use Plastidip on some of the electronic boards that gives it a
kind of waterproof coating. More recently we were told of stuff called
Magic-Gel. You put your electronics inside a box , fill it with t he
gel , goes solid and is not conductive. Its a bit like Argo-Floats and
immersing all the electronics in oil , so nowhere for the water to get to.
Wondered if you hada problem with consendation as much as seawater
We've not had condensation problems.
Do the organisers allow you to see their GPS system beforehand,
as you said yours and theirs were different? A fixed offset all the
time or varying?
There was nothing secret about their GPS. We didn't get to
look into it as their boxes were taped shut. As there was something like
30m difference between the two in the collision avoidance
challenge, it may be sensible to place their system and ours in
one position , prior to the race next year, to check for any offset.
Were the grids the same for the different classes?
I think the bigger classes had bigger grids to search, 20x20m grids ,
we had 10x10m boxes.
We're the bigger boats better at the tasks?
In some tasks yes, not necessarily due to the size of the boats.
Teams bringing bigger boats were possibly better resourced,
more experienced , like the French team.
Generally the bigger boats wwere better at picking up speed
before tacking and the speed is relativw to the boat size.
The Froude number is much larger for the larger boats.
What are the challenges to get one of these such boats to cross the
Atlantic, just funding for a more robust boat or?
Getting a tiny boat cross the sea has many problems. We know of
a boat being kept by some fishermen, another attacked by a shark.
Some the servos did not last even 24 hours, because of severe sea
conditions. Waves of 7 or 8m with a boat that is only 2m , not nice.
There isa team near London that launched a mircotransit
attempt from this area , got into the channel but with the tides and
things it never got out of the channel, just being pushed back
and forth, and eventually washed up on shore.
You need the endurance of power for the computers as well.
We currently use a USB power-bank that would otherwise be used to
boost a mobile-phone power, works well. Alsoa set of AA batteries for the
servos. The Microtransit boys have solar panels on theirs and
batteries so it doesn't die in the night.
Just the ability to keep going without stuff breaking ,
for the lenght of time involved and make headway against wind and tide
and big waves. A number of teams start out each year, west and east
going across the Atlantic and so far no success.
How does the robotic control fare against human control, say via
When everything is going smoothly , then the robotic is comparable to
someone without much experience of r/c sailing. A good r/c sailor
could always beat our boat.
Monday 12 June , Dr Roeland de Kat, Soton Uni : Forces and
turbulence in avian flight .
27 people, 1.5 hours
Over about 10years I've done bits and pieces on avian flight.
Today I'll talk on forces and turbulence. A lot of this work
has been done with David Lanthing? who now has his own lab
at Stanford. I'll squeeze in some Par-avian flight and finish
with avian turbulence. The main reason I'm into this , is because these
little creatures are amazing. You see them flash by and you don't fully
appreciate what is going on . I spend a day with a high-speed camera
chasing gulls on Southampton Common. A 400 fps video of one in slo-mo,
flares off, stops in mid-air, drops down seeing something I could
not see , takes a fish in the beak and goes straight up and out.
A lot of things going on there and a lot is beyond my expertise,
thata why we need to work with different types of people.
My background is aero-space enginering and so I can figure out
some of the elements of its flight. A pic of a swift, amazing
fliers. David Lanthing picked the swift because of its intermittant
flapping and level flight. As soon as you see something flapping,
engineers and biologists say thats way too difficult.
So we need to know a bit more about what is happening.
One thing David observed, in seeing them fly , they change their
wings, have them spread out or swept back. I was doing my
masters in Delft and David asked me to work on this, swift flight.
So we looked at morphing wings, how they control the glide
performance of swifts. What are the forces that act on the wings
, how the forces change as they change wing shap[e and what does that
mean for flight. We both had engineering backgrounds is the gait?,
thats not right 5 degrees, 50 deg , its meant to be 0 degrees,
60 degrees. But somewhere in the process of removing the
body of the bird, freeze-drying the wings, the wings did something by
themselves. When we put the wings in the freeze drier , they thought they
had them at 0, 15,30,45,60 degrees, but we needed to quantify it.
So part of the wrist , the sweep angle and that changes. We don't always get
what we want. A colleague a true biologist , we said to her this is not
true 0 degrees , she said its within 15%, that is biological variation it
explains everything. We went about quantifying different sweep
angles and a few other things we care about when talking
about aircraft and flight. The aspect ratio , generally linked to
how efficiently the wing performs and the wing area as the bigger then the
more lift produced. Classically these are just parameters; you pick,
you set and then forget about it and design your aircraft. Our flight
machine includes multple wing areas , multiple aspect ratios .
The first tests were forces, classically drag and lift , we want he
highest lift possible for the lowest drag. If you want to compare
a swept back wing to a straight wing , one bird , one wing ,
can change it. So instead of going at it , like an engineer and
normalising everything into non-dimensional things , we need to
take into account , it can change its wing area. If you put the
wing area back into the equation , then you see the differences between
the different stances becomes much larger. The envelope
plot , going from wings straight all the way to swept back.
If you change the flow velocity , keeping the medium (what is
flown through) the same, keeping the size the same , change of
velocity changes the Reynaulds Number, the paramete rthat tells
you how difficult it is to deal with the flow. The higher the Reynolds number,
the more complex the flow gets. The lower the number , less complex the
flow gets. If you add particles it may get more complex again ,
one of my colleagues work there.
Adding this in , we have to take into account , this occurs in a flow
regime , where things change. They change from lamina to turbulent .
If we add those different velocities int play, 5metres per s to 30mps, cranking
up the wind in the wind tunnel, the dashed envelope line , changes
further. We can scan the parameter space of what we expected these
birds could do. A bunch of numbers, that don't necessarily
mean anything . We took those numbers and put them into a glide
model. They are flying in different poses and we know trhey
are fully balanced. We have the lift and the drag from our
equations , an estimate for the weight , then say if it flew with this
velocity what can it do, and at a different velocity what it can do.
Not just a glide but what if it flies in a spiral. Swifts swirling across
streets , they glide and like to turn rapidly as well, quickly
changing their sweep angle.
Generally in aerospace engineering , we ignore a few things. Generally
we say gamma is small , a small angle, so we can neglect a whole load
of terms. But we needed this , to fully describe bird flight.
Equations , looking at performance indicators, how far forwards can it fly
with a 1m drop. Or 1m down , what is the slowest I can go down. The sink
velocity , the glide ratio. Maybe it wants to escape a predator, maybe you
want the ground speed to be the highest. Then some turning velocities
and performances as well. Whats the largest turning angle we can
get per m of descent, what is the tightest turn we can make , wha tis the
quickest we can turn. Below 45 degrees , gacefully falling , about 45 degrees
gliding ? flight. An easy cut-off , 45 degrees. Most follow the
same trend efficency peak at the lower velocities. Anything more on
efficacies or group-power can peak at the higher velocities.
Looking at the glide ratio, we can already see a few interesting things.
Peak is exactly where we expected. At undergrad level aerospace , for
straight wing, highest aspect ratio , is the best. Glide ratio of
about 11 . Estimates for albatroses don't go much higher , 15 or so.
So a pretty good glider. As we increase velocity , straight wing is
not the best any more. Initially this was a surprise, why is that happening.
Looking a bit closer into this, that is what we could expect.
If you take into account , the area of the wing, wing area changes.
Return to the curve with high lift, low drag, that needs to balance with
its weight in flight. Increase velocity , the coefficient goes down ,
poorer performance. As we go to swept back wings , performance gets
better again . Performance improves at higher velocity
purely due to the area change. Change your area, you can stay at the
better performing part.
Q: Does the angle of the wing vary over the wingspan as well, in this change?
Likely. But thats an additional challenge, not included in this
presentation. We looked at the deflection of the wings, from the
rear, at different velocities and they do deflect a lot. Lots of pics show
that swift wings a pretty well planks as wings , not a lot of
twist present. With our prepared wings, the twist was not
big enough to quantify.
Q: When you say whan the aspect ratio is very high , it changes the
wing area ?
Wing area plays role as well
Q: But on an aircraft , wing area is always the same, irrespective
of sweeping the wings back , so why is this different?
THe feathers overlap , when they start overlapping more , the
area changes. The benefit is, instead of having the small
difference between straight and swept back wing, here there is a huge
difference because area plays a role. At equilibrium balance at about
7mps, if it goes faster and faster , there isa curve that says
, equilibrium is lift^2 + drag^2 = weight^2. When that moves down ,
it shows how swept back wings perform better at higher velocities.
But does it really fly at those speeds. We tok data from a
different study Beckman & Alistahn? , the most probable flight
velocities, the most observed flight velocities.
The velocity swifts are recoreded at , fall in this range , and fall
in the range of all the efficiency parameters, not the efficacy parameters.
A lot of measurements , a lot of observing a wing in a wind tunnel
doing nothing at all, for about 2.5 weeks, 9am to 3am, very
tiring . Now for the vortices. If we take these wings , placed in a
wind tunnel, what I found intriguing , sold me on it, we have
leading-edge vortices. Before I started my internship 2004, showed
on a model wing with vortices. But engineers would say in the
1950s we had such vortices on swept back wings. Something else with
wings may have a role, they are porous. So do the LEVs make the
wing more efficient. We need a way to capture them and measure them.
So took a tin can, cut a hole, weld something into it, take a cigar,
put it in , high pressure air added . have a rake on the other end,
hold the rake in front of the wing, puff the smoke and you can see
the vortex. That failed miserably because cigar smoke is very
moist , a lot of tar, so imediately clogged up the tubing.
Trying loads of things, took a tuft of my hair and we used that to
visualise the flow. If you see rotation, then the flow is pushing my
hair around, ie a vortex. You can follow it into the tip vortex ,
the key is it started turning in the position of a LEV.
So we logged , moving of the hair around and whether we saw
rotation or not. Pictures of where there was a cone and not a cone,
and showing , for the rake used, it does not create it by that and what
we were doing. So there were LEVs but not present in any of the cases
where there was peak efficiency. So wherever the swift flies most
often , there is no LEVs. Where it did show up and where 1950s
engineers designed it around as well , you have increased efficacy.
A peak lift that you can create , you can turn very quickly .
If in a dog-fight or chasing insects , and the target goes off in one direction
, you need to go after it. Thats where it comes into use, where they use their
LEVs. We've only touched the tip of the iceberg of research
into bird flight. A lot of current research into capturing what living things
do , and build them ourselves.
I moved to Soton, to look at turbulent boundary layers and develop
experimental techniques. The first thing I looked at was a feathered
dinosaur. So a small dinosaur and similar approach to the
swift research. Take a model, place in a wind tunnel , get forces,
make predictions as to what it could do.
From the fossil record, such creatures are flattened out, feather
material . So a crow of its day, irridescent feathers , but could it
fly, how well did it fly. Some previous researches CL of 1
sounds good , glide ratio of 15 sounds good, combine and a very
good flier. So a colleague Colin Palmer found a pigeon in his yard,
bought a duck and created a model. A long tail, feathers on the
legs, and feathers on the wings. Whats this with hte legs.
Paleantologists bamboozled, perhaps everything was spread out.
Some people whan young can put their feet behind their head,
projected reasonable extremes, given the bones, what it could do.
Legs sprawleded or legs down and asked does it fly.
We put it upside down , because the balance in the wind tunnel is
at the top . 2.5 x 1.5 m with the animal in there of about .6m span.
Something at the rear thtat pushes it up and down, changes the
angle of attack , little weights and servos to capture the forces.
Lift and drag as before , but this time we add the moment.
With centre of gravity and moment at non-zero , it will
rotate. We wanted to make surre that whatever we say it can do,
as it doesn't turn like a leaf and roll or flutter down.
So the moment about the cofg needs to be 0.
We tried to measur ethe moment with the earlier swift work
but we failed. Luckily there are plenty of accounts that
swifts can fly and do so without their tails spread, in the vast majority
of poses. For swifts we could ignore the tail and it was fine, the findings
not affected by not having a moment.
Other researchers avoided this also, saying there were various points
it could fly. We accounted for it , with speed specific dynamic force
, which is basically the total force and then splitting into lift and drag.
The glide ratio, speed specific moment, and regions where it could fly and
some areas where it is not stable. If it moves up, makes the moment
larger , keps moving up and you get a confetti effect. To fly there
it would need a big brain, which is up for debate.
Elsewhere it is stable , not requiring a brain, and just jump out
of a tree and fly.
So jump out of a tree, make your pose and see what happens.
With fairly simple assumptions you get to glide paths. Initially showing
legs down is clearly better than legs sprawled. Then the engineer comes in
and maybe it could move its arms back and forth, so we need to
account for that. We modelled that by saying it could move its cofg
wrt the lifting surfaces. That tilts/ shifts the moment up and down .
As the big/small brain debate is still ongoing, we just say there is an
unstable part and a stable part. If small brain and not a good
flier , it can fly in that section. With big brain, advanced controls ,
it can fly there as well. Stable areas, no thinking required, areas where
it could glide but needs to work hard. Compare the 2 plots and
its not that different. Jump out of a 30m tree , glide-path, if you want to go
farther with legs sprawled, we think it hasa bigger liufting surface.
Go to the side, with the wing feathers, it goes up.
I started loking at turbulent boundary layers TBL on bird wings.
A flat plate is boring com[ared to a bird wing. We thought
behind this was some meaning as to how flight evolved in
feathered creatures. A wing is not a flat plate, the feathers overlap,
and in the overlapping there is a roughness. Feathers are not all
smooth or not flat at the top. To get a good force out of an
aerofoil , first year students are told it needs to be flat, a sealed
plane, flattness 0.000 something % flatness. So how does the
roughness work here. The lakidys? with the veins around it.
Shone a laser with lens in front, take a picture and get a cross-section.
Fairly smooth and as we move outwards, gradually gets more
corrugated, looks more like a dragonfly wing than bird wing.
They fly much faster than dragonflies , a different flow
regime. Measure them, abstract the average curvature , because it
has nothing to do with the surface roughness, colour code the
height , then compare that to the average chord, about 37.5mm
, peak to peak it is 0.8mm , 2% of the chord instead of those zeros something %.
So very rough, it must have an effect on the flow, must be fully
turbulent. So wing in the wind tunnel , to find where it is
turbulent flow and where it is lamina flow, skip the bit in the
midddle as too difficult to deal with, but there is something other than
those 2 flow regimes. If we used a hot-wire as for measuring velocities,
it would probably cut the wing. Use smoke and you might create
a wet wing, very different to dry birds. The best thin we came up
with was a microphone, with a very long tube on it. Build it right
and its only sensitive to pressure fluctuations at the tip of the tube.
Traversing the wing , patches of single pitch
noise , not turbulent. The hissing sound is lamina separation .
So we move our listening tube along the wing to find whare the sound
changes. It does not change randomly as turbulence is
quite well defined i na broad band signal. The tonal noise we were not
sure what to with that , I'll come to. Put it in Fourier transform
analyser and you getr what frequencies in there, high low, broad or nothing.
You look for where there is extreme change, that is where we go
from lamina to turbulent. Mark with dots where the changes are, do the same
thing for 4 angles of attack, times 3 wings. We take 0 , half way and
maximum lift to drag, which is whare its interesting. Also where there
is maximum lift , or stall , whare you'd expect changes to happen.
So we locate where the changes are, but thats not where the
roughness is. Where the roughness is, no transition .
Everyone tells you , going through aeronautics, wheere its rough
there is transition to turbulent flow, the worst thing you can do to your
aircraft. Swifts don't care about this , they just do their own thing.
Flow is not changing instantaneously , turbulence is not
something , clicks over now lamina, now turbulent.
There is a transition process, in one place with a certain Reynaulds
Number, transition may only occur later on.
So an area with lamina flow , and whaet
that means for the bird.
For different angles , its primarily lamina. The peak is almost 75%
lamian , or at least non-turbulent, where it wiull perform its
best. Thats where it flies most , unsurprisingly. How do we
know its not just a thing with swifts. How do we know its the
roughnes, by testing. The swift wing , with calipers trying to find
where the ridges and valleys are, then I used a laser scan.
We built a wing with thin pieces of tape attached. It has one
width and tibs and one without. We used the listening tube
again on this. The rough has more lamina area than the smooth,
low reynolds numbers. As we increase velocity we get
back to normal. Big aircraft with big Reynolds numbers,
flying fast. Aswift isa small bird , fast in bird terms but slow
in airliner terms. Right about the range where these birds fly ,
rough wings are not bad, in terms of lamina area.
What does that mean in terms of performance. Mor elamina
area means better performance, not necessarily.
Our wing, lower reynolds we do get bettewr performance.
What is going on in the flow, we still needed an answer.
A masters student in Delft took the roughest lines measured
profiles of the wing, averaged them , measured under a microscope
the leading edge radius of one of the feathers , estimated the thickness,
to produce a 3D printed model. Then remove the roughness, make a smooth model, 3D print it . Now anything you machined
or 3D modelled will be as you intended it to be.
Its not far off. Placed in a water tunnel. Luckily a low velocities
, air behaves as water , as long as you match the reynolds numbers.
With water, the forces are 4 to 5 times higher, so easier to measure,
or so we thought. 3 cameras looking at it, placed a load of
particles in there , watch where they go and we get velocit y
fields. We tested 3 angles of attack, for 4 different reynolds numbers
and the range where we expected changes to happen.
Not much obvious differences. So w etook snapshots , summin g
and dividing by n . Looking at vorticity, so
rotating 1 way or the other, or shear. Low angles of attack nothing
there, intermediate angles a little hint of something there,
high angle of attack , definitely something going on .
Vorticity is not too natural a thing to look at. We zoomed into
small area and looked at vector representations, much easier to
interpret. The vortices that get induced are the
tonal bursts you heard on the video recording.
Vortices move , they're periodic. In the global view we might not see
it. In aeronautics we reduce it to a bunch of numbers, describing what the
flow is doing. Boundary layer grows as it goes over an aerofoil , it has a shape
and it can be quantified in multiple ways. Generally we pick
boundary layer thickness, about 99% of the external flow.
Then we can determine how much velocity you would need , rathe rthan
a curve , you make it a straight line, the displacement thickness.
Then you can work on how much energy is lost.
With the boundary layers , you get an inflection , a separated
flow , flow is not attached for poor performance.
There ar efluctuations around the average profile. Boundary layer
thickness. not much difference rough or smooth. The shape
factor , one of the indicators of whether flow is turbulent
, lamina or separated. The bigger wake is generally
indicative of a separated regio n as well .
For the rough, we get vortex trains for intermediate
angles of attack where peak performance is.
Low angles of attack, no vortices , lamina flow over a rough
wing. High reynolds nubers, they both go turbulent.
For high angles of attack , smooth and rough wings are little different.
This is where a swift wing performs and a smooth wing does not.
The beginning of the wing, kicks the flow , it gets agitated and stays
attached. It does not separate , it follows the wing.
Although turbulent flow is bad in causing drag, its a lot
better than having a separated flow as that would mean
I have a PhD student also interested in feathers but he comes at it
from a different direction , as a biologist. So we loooked inside
feathers. Taking a swan feather to pieces , placed in a
syncratron a large particle accelerator . The particles shoot through
the feather and a scintilator , turning radiation into
light and look at it with a microscope. Move around 40
times. The core has a patterning , but move to
the outside no patterning. The material properties change.
Also there are multiple layers in a feather. So beyond
avian aerodynamics , one of the most
complex advanced composite structures i nthe world.
So the next research is trying to determine what the layers are, which way
the fibres are pointing . We could then model the composite, tear it
apart again, and see if we can tell something about it.
Hopefully allow us to build better structures, maybe improve
small-scale flying objects, wind-turbines or whatever.
You said the wings were porous , so with bats where its just a membrane,
would htat behaviour be more like conventional aerodynamics. ?
Feathers are porous but for most lifting purposes
We try to model the porosity , and we failed. Wheras swift wings
use roughness to keep the flow and keep the flow
attached, what membranes might do , is changing the camber, the
curvature and more lift, but it vibrates more.
With a vibrating membrane, it does the same thing as roughness,
energises the flow, it creates vortices , keep the flow
attached. A completely different phenomena but the effect is the
How much air goes through the feathers.?
There are people that look at the permitivity, its very little.
The latest model I've seen , they've tried to 3D print .
From the bones you have the feathers, from the radius? you get the
barbs. Optically it would seem to be porous but when you pressurise
it , it tends to flap and close, and closes. People apply pressure
differences , to see how much goes through.
They try to model that in 3D printed wings, by creating simple
holes, and they are not the answer ,as the flow goes through,
resulting in fully separated flow. There is some work on the outermost
primaries of storks,where there isa hole and the rest seems closed
, if they close that gap with wax , the feather which is a single aerofoil.
performs worse. Little holes may have jets emerging, that may keep the flow
attached on top of the roughness. But that varies, species to species and so
many species out there, its difficult to say, this is how feathers work.
There is likely some flow coming through, its too small for us to
With the albatros , a high aspect ratio?
Its about the same as the swift.
Can the albatros change the shape of its wing, for more speed?
The albatros has a little ligament in there, places it, and it locks.
Without any effort it remains straight. Swifts have loose wings, and they
have to force it. Different species have different mechanical
solutions built in, to help with their flight behaviour.
The albatros flies much faster than the swift, bigger ,so its in a place
where it will not benefit from a rough wing.
A barn owl flew in front and across me , one dark night, with a
wingtip just 1 or 2 feet from my head, and I did not hear a thing,
whats going on there , a very downy wing surface?
Multiple things, the easiest one, its very slow.
Slower means less drag nd so less sound. The second is flexible
wings, the feathers are less rigid than other birds, so
creates less or lower tone. The design is such that it gets the sound
generated but out of the range of hearing by its prey.
There is sound , just that its not audible to humans. There are
pressure fluctuations, but they're not audible.
It has a velvety surface, the precise texture is difficult to say.
May have some porosity ads well , so the pressure passes through
it rather than creates sound. It has a large wing and so a low
So infrasound or just sound below our hearing range?
Found a journal article, "Features of owl wings that promote
silent flight". They say the shape changes, wing area is large
compared to the overal bird. There is a little serration at the
leading edge, that probably creates vortices that keep the flow
attached , as separated flow makes sound, and any unsteady
flow makes sound. Another article measuring the sound from a
wing at different frequencies. One of the influences is the
comb, the serrations, of the leading edge. A lot of people
are interested in owls as they desire to reduce noise in other
areas of flight. They use an acoustic array, a bunch of
microphones and arrange flypasts. With some maths you
can reconstruct where the sound may have come from
at a particular frequency. Repaeated with different types
of birds. There was a BBC doc on the silent flight of owls,
where they compared 3 of them flying around.
Everything in biology is designed towards a goal, but its always a
trade-off against other things like mechanical structure .
Do you feel the roughness of wings is an exploitation of the
fact they've not managed to evolve smooth wings or do you
think it was very deliberate selected for the ideal shape or some
combination in between?
In the water tunnel experiments the forces were comparable
between smooth and rough wings. So if you don';t have a penalty
for hving a rough wing or in some cases it may be beneficial
for performance, then its always better to have structural elements
that have some bulk , in the direction of loading , rather than a flat plate.
So probably why little bird-like fliers, millions of years ago
might have taken advantage of having something strong enough
, but still bulky , without losing too much aerodynamic performance.
Its not necessarily driven to that goal as the main thing that
drives evolution is where is my dinner and I need a mate.
When you can satisfy those 2 , then you're good enough, or maybe
escape predators. That does not mean it drives for perfection ,
drives towards suitability for its environment.
One thing that peaks the swift , is they are pretty much always on
the wing, eat, sleep and have sex o nthe wing. Only landing to
sit on eggs or feed the offspring. After first taking off they fly for about
3 years before finding a nest.
How do they sleep?
Like dolphins , brain one side off , one side on
On the opposite side to noise , one thing I've admired about
swifts and swallows is their ability to just turn on a sixpense i nflight.
The onl;y fixed wing aircraft I can think of that does anyyhing like it
is the typhoon and even that cant turn as quickly, for the speed its
going at. Your research on angleof attack and roughness and
sweep-back , does that account for the fact they can turn so swiftly
at its speed or is there something else going on? eg can it stall
one wing and produce maximum lift on the other, in order to
turn as quickly as we see it do?
It might be able to do that, but it might be able to do
better than that. Someone buit a robo-swift , mimmicking what it
does. It uses asymetric control and move. I-morph / Bluebear? systems
, uses a similar structure to move the whole wing, what they don't change
is turning one up and one down and turn like a corkscrew.
So fly the plane sideways . If you end up turning on your own axis then
you do have to use fifferent angles of attack . What they seem to do is
swept back in dive , flare-out completely, catch up a bit , tail full
out to keep control and then continue. So if an insect made a basic
manoeuvre it could pounce on.
Some of turning-on-a-sixpence may be an illusion because they are moving
really fast, take it out, and may be more of the curvature of a football.
Its difficult to tell at a distance, we just see it turns.
When tohe paper on leading edge vortices came out , 2 of my
colleagues wrote a commentary, turning on a dime. Instead of comparing
with the typhoon they compared to the F14. The F14 has very different
reasons to sweep its wings, than swifts.
The hole in the stork wing, is the hole intentionally there?
Slotted wingtips with spread out feathers , you can treat
them as single aerofoils , rather than needing to worry about
how much they overlap . Take one feather, place in a wind tunnel
and see what happens. A little hole just before the turn .
They tested by closing those holes with wax and find the difference.
When there are holes in the feather , it performs better.
So it comes down to , a bit of passing air might be beneficial.
Its not that dissimilar to when we take off or land.
Take all the slats and flaps out, there is more air going through .
Probably tested at one speed only. Not just wind tunnel tests
but stuck it on a car and drove at thre correct speed, to make sure
the ? speed turbulance was not affecting the result.
The reason behind that is sound, even if it sounds odd.
Have you looked at commercial applications of your research?
What is of interest right now is the morphing wings,
lots of different people. My interest is not necessarily
commercialisation , just figuring out what is going
on. With morphing wings we know it performs slightly better.
It can do multiple functions at the same time, but the best design
of how to malke it better , we have a masters student looking into
right now. What strategy of morphing wings is beneficial for
performance. Also the composite structure has potentials.
I've heard the albatros is the most efficient animal in the world,
in some sort of terms. Is there some sort of a ratio between what
birds have achieved and the most efficient human wing ever developed. ?
Roughly speaking, the faster you go , staying below mach trans-sonic range,
the more efficient wings become. Humans can make wings that go much faster than birds
so they are more efficient.
Its a bit comparing lemons and pears. A human built plane will
weigh more than a bird, but for an equivalent speed to weight
ratio , how are we doing in comparison, to evolution?
Go down the scale from birds and bats, to insects. Everyone is
raving about flapping wings. Except they forget one thing, did you
try swimming in molasses. They need to do that , as there is no other way they
can fly. It doesn't mean its efficient , it does mean its the only
way to fly. For biology , sometimes, its not a matter of flying the
most efficient , its flying enough to get you eels . Flying enough to
have the edge. For the microraptor it is probably the equivalent
of a flying squirrel today, just flies from one tree to the next.
I notice bird wings seem to shed water with remarkable efficiency,
water off a ducks back?
Depends on the species. Owls can't fly in rain.
The wings don't function because they get water logged.
The cormorant needs to dry its wings , to fly well.
Some underwater flying birds don't have oil, don't preen
the feathers with oil, because it makes them too bouyant.
In bad wether owls are grounded. Probably due to
extra weight and destroying flight characteristics.
They have to wait until it gets dry. In dutch we call them
church owls because we first noticed them appearing
in churches rather than barns.
Birds fly slow compared to things we make , considering
dimensionless numbers, is there something that charactises the
different regimes slow flight v fast flight . Do wind-turbines come
under the heading of slow flight or are they fast?
To characterise what the flow does, is the Reynolds number,
has the density, the velocity , a length scale divided by viscosity.
Viscosity is water v honey . The bigger it gets, the higher the
Reynolds number , the more chaotic the flow becomes .
Or in terms of TBL the reynolds number is the ratio beteween the
largest scale and the smallest scale, how complicated the flow gets.
So fly very fast if very small and still have the same
Reynolds Number. Go very slow and be big and have the same Reynolds
Number. So take a F1 car , scale it down , put it in a wind tunnel
, you need to run the tunnel faster , to match the flow conditions.
So swifts are at the wrong end as they are small and slow ,
but luckily there is a lot of interest in micro-air vehicles,
drones , UAVs .
Monday 10 July 2017, Dr Tony Curran, Soton Uni : The Carbon Footprint of Food
36 people, 2 hours, audience interactive competition sections not transcribed
The burger apocolypse. A graph , on the x axis how many C tons you can
potentially save by doing different interventions in your lifestyle, to reduce
your impact on the environment.
so changing your diet, saving about 2 tons of your C arbon footprint (CF).
The average CF is 15 tons per year in the UK. The y axis is how much
money you could save. Its more than any other intervention like changing your
transport , how hot your house is.
What would be your perfect burger, typically its a beefburger, by
sales anyway. The Heart-Attack Grill , in the USA, their slogan is
taste worth dying for. They use it as part of their marketing, that
people regularly get hospitalised , directly from their restaurant
because f the food they eat there. They have the bypass burger,
very big. The double bypass burger , the triple and quadruple bypass
burger, 10,000 calories, 4 to 5 days foodworth for the average human.
This is Las Vegas ,sin city, so they now do the quintuple burger and up
to the octuple burger. If you want bacon on it , not a couple of rashers but
40 added to it. When you go in you get weighed and if you weigh in at
over 25 stone or 160Kg you eat for free, the American dream.
Its become part of the UK culture, steak nights or burger challenges
and overconsume especially meat . It didn'y used to be this way,
now its trendy. Leading to a lot of negativ econsequences, both for the
environment and human health and also financially.
The environmental argument. Beef cattle like lamb, are ruminant
animals, the digestion process means they generate a lot of
methane. About 34 times as potent a greenhouse gas as CO2.
It also takes up lots of land and lots of water, about 70% of
all the water we use in the world is for farming .
in terms of land about 3/4 of all deforestation is driven
by forest clearing for soya production often, to feed to cattle.
A graphic of the weight of all the animals on the earth, section
for all the humans, much larger section for al the cattle we keep
for our consumption. Also the lambs pigs,horses and then marginalised
is all the wild animals. We've pushed out wild animals by monopolising the
earth for our own ends. Maybe we could reduce how much beef
we eat. There are some trends to move to a lower meat diet, compared to
2006 beef consumption will go up by 95% in 2015, largely due to
a more affluent China.
Businesses and governments habve a roll to play but individuals as
consumers have a bigger roll. So the ABC of low-C eating.
A = Avoid wasting food, about 1/3 of all food produced is wasted.
That is about the same in the UK or globally, total food waste, in the home and supermarkets, about
7 million tons pe ryear in the UK. Globally 1.3 billion tons yearly.
How much do food safety laws impact on that statistic, sell before dates etc,
or the seller is liable to legal proceedings?
Yes directly and also indirectly as people will throw away food that is
perfectly healthy, just because of the date on the packet, I'll return to this topic.
most of the food is wasted beyond the retail point, mor ein the home than
in manufacture or farms or supermarkets, about 20% wasted in the home.
So if we go to a supermarket and buy 5 bags of shopping we effectively
chuck one of those bags into the waste bin.
Half a ton of CO2 equivalent for the food that is wasted. About 28%
of all the agricultural land is used to grow the food that we throw into the
bin. Considering we hope to feed 9million people in the next few decades.
Again huge amounts of water used on this thrown away food. Valued at somethong
like 5 billion GBP per year.
B= Buy in season food
The CF of a lot of fruit and veg can be 10 times higher i nthe off-season.
A lot of people say buy local, but the research I've done is whether it is
in seasoon is more important for CF .
Take the example of bananas, come from 5,000 miles away , but tens of
millions on a single ship and so lowC. The same with oranges from
Spain. So both are healthy things to eat all year round. Don't tell
people , not to eat them, just because they are not local.
Spin that on its head and consider strawberries, between April and sept
are in season . Fine to eat, lowCF, cheaper , tastier and perhaps more nutritious then. Out of season probably hot-house grown
in Kent, using artificial heat , so way higher CF than bananas from
5000 miles away.
April to Sept is a very long season, I live in a strawberry growing
area . Growing them under plastic in April and Sept monthes must be a
lot more expensive than just eating them in June and July?
If you use polytunnels , yes it would add something to the CF, but
little compared to artificial heating. but it will extend the season,
the same with tomatoes.
Conversely take the example of asparagus. It is atiny growing season
about mid april to end of june. A week ago i na supermarket , some was still
from the UK. Go now onwards , all the varieties of it you see all the
way to april next year , they will be grown in Peru.
Because it perishes quickly , it will be flown in , so the CF out of season
is about 30 times higher. Enjoy them in season, then eat something else,
there is always something else in season.
What if the season was not july, i've constructed a food
seasonality chart, along the term each month of the year.
Look down and see what fruits and what veg are in season in that
month. Place the chart, downloadable from
on your fridge, also the interactive games are on that site .
C= Choose low CF food more
Its difficult to know , often , which foods are high and which low CF.
Between 20 and 30% of all greenhouse gas emissions are in growing
our food or in the food system. Its the area we can make most savings
, relatively easy, without masssive lifestyle changes.
70% o fall the fresh water we use , is for growing our food
75% of all the deforestation is driven by land clearance for
agriculture. So if we change the kind of foods we eat, we don't waste it,
then we can make big inroads into reducing these numbers.
For many years I've been involved with economic developement in
the third world. They earn a lot of money exporting products to the
UK. So if we moved to a more basic lifestyle, cutting back on imported
food, grown in the third world, we are reducing their economic take.
How do you balance those 2 things. ?
There is no simple answer . Its much more general than just
food. We are a global economy now and such things will have
consrewquences. We can reduce our effects on the environment is
be a bit more local, in our production. In my ABC
, biased towards seasonality rather than buy local . If we have a
big transport footprint , millions of bananas on a boat , which
will be producing greenhouse gases, more so with flying.
Articulated green trucks , in the future, interesting to see how
that develops . In the near future thats not a solution.
We should not eat the same foods throughout the year , but have a seasonal
diet and then local products?
If we go back 100 years, or 70 years, wartime, nothing
was wasted. Most of it was local and self sustaining. People grew their
own food out of need, and was a low CF lifestyle.
Wouldn't it be great if we had urban food growth, self sufficiency
i nthe local economy, it would be low CF, the greem ethic.
Thats true and would be nice if we had it, but its not the
reality. We're moving to 9 billion people, becoming more urbanised
population . We don't have the space and most people don't have the
inclination to grow their own food. Hence we will still be
dependent on a marlket system. We have to be carfeul how we do
that and mindful of the impact on other places. To some extent there will
be a local element and that must have an effect on other areas.
It does not have to be too big an impact as I say seasonality
is the primary changer. Bad working conditions in banana plantations
is an issue that must be tackled , but it vcan be a healthy
source of lowC food. Lets not cut that off , just because its not local.
Balancing the ? , factory farming produces much less CO2 , but then
it also uses antibiotics , terrible animal ethics . Organic farming
uses much more land. Mor ewater and more CO2 produced, otherwise if
you want to eat meat. ?
There is no right answer , you cant tell someone where their
priorities should lie . A lot of people going vegetarian or vegan
, do so for ethical reasons and others for environmental reasons.
Its true, if you mass produce , especially something like chicken for
factory farming or for eggs. Or cattle in horrible indoor conditions,
that is unethical and low animal welfare. But the CO2 is lower,
so where do your priorities lie. If you want a lowC diet and want to eat meat
then it would be better to go down the unethical route. The if at the
end of your question, we can eat less meat. Everything in moderation thing,
eat meat less frequently then you could say you will eat free-range meat
, at a sustainable level, if you consume at sufficiently low quantities.
I give talks on energy and general consump[tion and I always have to say
to people, reduce our CF and we'll be back into the stone-age.
We want to reduce it to the level that is sustainable
, stil 5 to 7 tons of CO2 per person, but its not 15 tons.
Get your overal CF down to that level , could be via lower
meat consumption that is ethically produced.
Theres a technology that may well be coming in soon, where on
brownfield sites around cities, they'll be putting converted
shipping containers and hydroponics inside to grow salad crops.
I can't fathom whether that is advantageous in CO2 terms
or the present large-scale growing and large transport costs?
The scientific answer is you have to do a life-cycle assesment
of this option compared to the current and see which comes out
better. Its comparing apples and oranges. There is this argument of a
move to locally produced food and in theory it can be sustainable.
Lots of examples around the world of urban gardening or urban
farms . The community has risen up , we will not be dependent
on food coming in from other places, unknown inclusions, unknown
effects . Help to produce it, pick it when you want. I'm synical
myself that they can rack up to feeding anywhere near
65 million in the UK, potentially to 70 plus in a decade or so.
A dreadful cycle, we must feed this lot , more children, more
food required, where is the limit?. If you are not prepared
to declare a boundary then there is an infinite line needing food?
Always touchy, what can you do about population growth.
It would be a really good way to overall reduce our CF, and impact on
environment. There is birth control and other ways of not forcing
people not to have children. For food there is easily enough space to
grow it, 1/3 is wasted, then there is over-eating.
We eat too much food in the Uk and globally . 800 million
people are clinically obese, of BMI of above 25/30 you are clinically
obese, above 40 and you are morbidly obese. But 2.2 billion
are classed as overweight, whether based on BMI , I don't know.
The stats that global organisations are using now.
1 in 3 adults, many children as well . This includes the people
who don't get enough food. Perhaps partly due to lifestyles
, not enough exercise, but mainly due to excess food intake.
Some people work so many hours, there is stress , and no time to
make soups out of chicken carcaces. We used to do it , but have we
the time these days?
And the convenience lifestyle has led to quick food , which is oftn
highly procesed .
In war most of the men were at war, women in the factories, on a massive scale.
People did not have time then. The government had control of the
food supply . These days we can consume what w ewant, when we want
and so we do.
So is food too cheap?
This was raised by Molly Kato? the MEP green party member.
Food is too cheap , you could say. But another tricky issue. About
1million people dependent on foodbanks in the UK. Bu tthat means the other
64 out of 65 million , have a high CF , because they are affluent enough
to be able to do so. Then all the knock-on effects, the health
service along with lack of exercise. Built around consumeism
a lot of issues.
I went to a do at Reading and there was loads of different insects to try,
but when I went on line , very small packets available, for ten pounds or so,
what is the CF there?
Eating insects. A speaker here on that Jenny Josephs. The CF is very low,
nutritious for the protein content. It has the potential to be
sustainable. Also with some energy solutions, we're not quite there yet,
bu tthe potential is really good. They can be stacked so little land use.
Hardly any water .
So why are they so expensive?
Like anything early on in the market staging. Not selling enough to be
able to produce at a cheap rate. We can talk about artificial meat,
meat substitutes is another one, insects is one option.
This is the impossible burger. Its new a meat free burger. The difference with
quorn burger , lowC but unpleasant taste, so not bought.
You don't buy such , because its a highC burger , you want something
tastey. Thats what will dominate people's purchases when it comes to foood.
The impossible burger launched in US , last year. It is plant based.
After 5 years of research , they've got haeme, as in haemoglobin , the
thing that gives it meaty texture, now harvestable from plants.
They even sizzle when cooked, the correct texture, burger-lovers,
meat lovers are tasting them and giving positive reviews.
This kind of thing can be the future. 1/8 the greenhouse gases of
a normal burger, hardly any water or land requred.
Is it heavily patented?
I suspect it is. They're quite open about the ingredients,
potatoe protein, coconut. A small start-up company in San Fransisco.
In regular burger joints its about the same price as meat ones.
Not mass-produced yet, and there are competitors. Meat free
pasties etc are becoming more common in UK shops and becoming
more tasty, so we're getting there.
In Oz there is a chain of takeway shops called Lord of the Fries.
They diversified from chips to burgers, but they never said it was all
mock meat. They've now admitted its been vegan , the whole
time thet've been serving it. Its of couse now a selling point
and thery're expanding exponentially. ?
A nice point. Jenny Josephs who gavea talk here . I was with her
Saturday where we both gave a talk at a festival. I did the general
stuff and she focused on insects. She did taste tests with meatballs
, sausage rolls, 50% pork , 50% mealworm or whatever, crickets etc.
People usually cant tell the difference between full meat and
mixed with insects, or prefer the insect ones as more texture
or just nicer. So don't knock it until you've tried it.
For a meat eater , more than 100gm of meat a day on average,
your CF is so much, for a vegan its about 40% of that.
More and more people are eating less meat these days, but still
a vast majority are committed meat eaters. We think only
3% of people are vegetarian , less than 1% are vegan.
Fish is a very lowC source of protein so the pescatarians
are only saving another 2.5% by going totally vegan, cutting out the fish.
You can save 12% by staying meat-eater but switching from
beef and lamb , the methane producers, to pork and chicken, the same amount.
On fish, the actual CO2 evaluation. They are wild caught are different
to farmed fish, with added nutrients. Is there full account made?
The data is based on real assesments that have happened.
We won't know the exact CF of every single fish, depends where its caught
etc. But generally wild-caught fish have very lowCF because
they feed themselves , compared to chickens say , where they need fields and
fields of soya and othe rgrains , to just feed the chickens.
Sending a boat out to ctch a load of fish, its not a huge amount of
diesel. There are fish that should be taken from farmed sources, halibut
is one species. Halibut is a popular fish, high demand. It takes a long time to
mature, 8 to 10 years. We've stopped intentionally fishing them
wild now , quite a lot as by-catch though. Good in many ways, it gives the
wild halibut the chance to recover. Farmed fish can be done at a
sustainable level, possible to factor in ethical measures, whether happen
or not is enother debate.
Fish farmed or in the wild still produce the same amount of faecal matter ?
They are cold, so their metabolism is much more efficient. Cows are chucking away lots of their energy , just to stay warm. It is an inefficient
process to get protein for us, using anmals that use a lot of the energy
just to keep themselves warm.
Would it be advantageous to consume wild game, as compared to ? game
Possibilly, its never cut and dry, it depends on the specific situation.
My stock answer for this, is do it at a low enough level, then its sustainable.
If sustainable in the ecosytem ,those wild game have enough food
and all part of their normal habitat , then fine. But more often than
not, the population of humans , going up exponentially and dominating the
Earth, in the last 100 years, it tends not to be sustainable. So we have farmed
or mass produced alternatives to meet demand.
At the moment we are over-run with deer in the countryside.
People are talking about reintroducing lynx to try to keep the deer
population down? so a good argument saying eat more venson?
Wolves in Scotland . Same with kangaroos in Oz.
Cutting down forests for soya production , is that the main driver or
cutting down for the sale of timber being the main driver?
Mostly the driving is for agriculture. For some tropical areas its for
logging , for the timber as well. But mor eoften its so the land can be
quickly cleared, to grow food as that is where the money is.
Eating organic. I beleive it is preferable as artificial fertilisers
ar ecut out, soil is preserved. There is a question about how much you
can get from the land. Permaculture with mixed crops , get more from
the land used in intensive agriculture. Could you give more clarity?
The film Tomorrow, a recent film. Its basically saying our current
system is broken. Not susstainable , we're having impacts at all
levels we need to reset society and think locally again.
Not just the food system , educataion, the economy what we
spend goes out to big multinationals rather than local.
Permacultur eis one aspect of that. A certain amout of land can be so
much more productive, but its labour intensive.
Again it comes back to busy lifestyle, it will come back to just 1%
of people who care enough , to do permaculture and have a minuiscule CF.
In my mind it will only be a small percentage, not the majority.
Permaculture is a nice idea, do it where we can.
With organics , yes an absence of fertilisers is a good point.
CO2 going into the atmosphere from all our energy and transport use.
Methane the cows are producing , that the paddi fields are producing,
the landfill is producing . Its 25 to 40 times higher than CO2 .
The nitrous oxide from fertilisers is 300 times more than CO2.
I was told fertilisers were the biggest contributor within food production?
Not true , its the biggest in terms of 1kg of fertiliser used ,
mor eglobal warming potential than 1Kg of methane emitted, true.
ut overall there is a lot mor emethane emitted than nitrous oxide.
Artificial fertilisers are bad in that sense but on the other
hand allows food to be grown quicker , or bigger or mass produced.
A second thing, not fully understood at the moment , is the soil.
Soil degradation, mass agriculture intensively, is damaging the
soil . Again ok in the short term , but like deforestation, short term we can
have fewer trees and we'll survive. It means our total ecological
footprint on the Earth is way beyond 1 planet earth.
We know hte oceans absorb a lot of the CO2 trhat would otherwise
cause global warming. The rest goes into the atmosphere and that is
driving GW. The third big C sink of GHG emmissions is the soil.
That bit is not well understood yet and intensive agriculture,
degrading the soil , is reducing its ability to store the C.
Potentially a big crunch point that will lead to runaway climate
No mention of GMOs. For example producing a better shelf life
and less wastage. Or produce rice that requires less water etc. ?
Again GM products are poorly understood. A bad time in the press.
Also a failure of science communication, badly comunicated to the
public and so generally the feeling is that GMOs are bad.
What might happen , and so a fear around it. But
actually it is scientific progress, solving real-world issues .
So developing a more resistant strain of a grain or veg , can
potentially feed starving people and do it where there may be drought
or flood tendency, and not loosing a whole crop.
A great potential for GM. There will be legitimate counter
arguments and exceptions.
As consumers we need to accept more responsibility, for what we
consume, more conscious of environmental impact, but there is also
a role for marketing to be controlled. The BOGOF business
and continual encouragement to buy more all the time, and then
throw it out. Can you see legislation to stop some of this
over-marketing of things? The wrong shape cucumbers thrown out
on the farm, even back in the 1960s?
There isa role for governments certainly. Brexit will mean we'll
lose a lot of the regulations, the EU currently has.
So implications there on environment and bio-diversity.
There is also a role for culture. There isa slight shift in culture.
Competing supermarkets are attuned to this , one supermarket is
marketting funny shaped cucumber and bananas and making that
a marketing thing now. Someothers are dealing with waste, Tesco
and Sainsbury, there. In France the government has told supermarkets
they are no longer allowed to waste food, they have to do something about it.
Legislating to make that happen there. I believe personal
actions can make a bigger difference overall.
The environmental argument tends not to be the main driver
for most people, hence my interest in the impossible burger.
Its usually taste that is the bigger factor with most people.
More than ethics, more than environment, nail that one.
Adopt some of my ABC measures of LowC eating , you can
potentially save something like 500 to 1000 GBP a year as a family.
Avoid the avoidable food waste, not have no food waste as not
realistic. Buying in-season food and switching to lowC foods more.
not extreme veganism , just beef to chicken change, modrate
amounts etc. A recent study showed that if we reduced our meat
consumption not to vegetarian or to vegan , just to the level the WHO
is saying is healthy for us. That would cut our CF by 1/3.
Go vegetarian it would be 63% off your food CF and going to
vegan is just another 7% to 70%.
When wil lwe see the CF printed on packaging?
Its unrealistic unfortunately. Some people have done
red amber,green markings but that is more to do with health.
Consumers want to know if its tasty, then whether it s
healthy or not for you, fat/protein/carbo breakdowns.
Peartly not enough appetite for it . Also too difficult as not only
depending on exactly what piece of fruit it is, whether
it was in-season when picked, the time it was shipped ,
refrigerated , th eboat route.
How many smokers wanted to see death warnings on their fag packs?
Ultimately it is legislation but I doubt there is enough political will
to make it happen. It becomes important to think of the health
arguments. THere is a good correlation , cheaper foods
generally are lower C foods. Also a reasonable correlation
between the health of food and CF of food. If you wan tto move to
a lowC diet , that cuts out a lot of meat, almost certain to be
cheaper , but also healthier for you.
The carcinogenic properties of red meat and processed meat,
and other comparisons can be made.
What is hte CF of beer?
Beer's a funny one, and also is it vegetarian. They often use
fish guts/ininglass to fine the beer. There is an alternative
used by Budweisser etc. The CF of beer is not easy to
answer . You could do a C analysis of a particular beer.
It has grains in it . For 1Kg of beef the CO2 equivalent is about 18Kg,
for cheese about 12, go to chicken or pork another third off,
about 6. Go to rice its about 4Kg. Wheat comes in at about 1.3Kg.
It will be higher than average fruit or veg in-season, but much
lower than meat or dairy products.
Fruit based alcohol , might be lower than beer.
Banana wine, the ultimate solution.
Could there be a cultural movement to wards beef and lamb
being considered a treat rathe rthan routine, as a way of moving
people towards less meat?
Some chefs have hooked onto the concept of meat-free monday.
I don't think it goes far enough but one good thing about it
is it gets people realising they'te not dependent on meat.
Its become normalised to have meat, if you have a meal
it must have meat. One of my main take-away concepts I emphasise
is move away from beef. A beefburger is 3 times CF of a chicken-
burger. Move away from the methane-producing ruminents of beef and lamb, and go
to chicken and pork.
An average cow doing its thing in a field , eating grass, regurgitating it ,
generated something like 300 Litres of methane a day. So much the same
asthe CF of a car use in one day , just from a cow being alive in a
field for a day. Lamb raising tends to be on uplands and poor grazing land
not useable by anything else.
If we go back to the sustainable level and have lamb once a month,
as a treat, then maybe that scenic upland life is the reality. But if we have it in the
quantities that we currently consume lamb, there is the hidden
reality of tens of thousands of sheds for raising sheep. Certainly so
for beef and pork.
Is there anything you could use the methane for, if you could harvest it?
Its not feasible. Its one of those out-there ideas. When we consider landfill
and waste management we do use the methane now.
Its sealed landfill these days , capturing the methane and it generates
electricity, relatively small quantities ,but mainly its not going
into the atmosphere. Change what you feed cattle can
bring a reduxtion of methane down about 50%.
A specific mix of plant foods will produce a specific micro-flora
in the gut , the metabolic pathway changes and less methane produced.
A common misconception is cows farting out the methane, but a higher
percentage is belched out. A bag over the rear end maybe possible but
the more necessary bag over the eating and breathing end is not possible.
Changing the diet of animals, you have to again consider the CF
of that alternative low-methane food.
A chef friend of mine , his dream is to produce vegetarian meals that
people would find captivating to look at and be tasty.?
Another way is via rice mechanisms. Say at Glastonbury there are loads
of vegetarian and vegan options , but what I do like
is where the vegie burger or curry is a bit cheaper. That often
does not translate down because of mass-production issues.
Composting query. Garden compost heap it breaks down , releasing
gases to the atmospher. Compare to going to landfill and anaerobic
We have loads of people working on composting and also anaerobic
digestion as a future solution for waste management.
I don't really like it as a solution in this context as it basically
legitimises food waste. Whereas high C , human grade food ,
should be eaten and not wasted.
Monday 14 August 2017: Dr Alex Dickinson, Soton Uni -
Engineering Replacement Limbs - a Global Challenge
19 people, 1.5 hours
Injured vetarans and services people have raised the profile of the
people without 4 limbs. This interest has allowed us to generate funding
for research into lower limb prosthetics(P).
But they don't represent the majority of cases, people who have lost
limbs through trauma or infection . Such as Johny Peacock represent only about 20% of the population who've lost limbs. Diabetes and vascular disease
account for 80% in this country. So we try to learn as much as we can
from the highly functional amputees, to develop technplogies to
help everybody. The clinical need , is from someone who has
just woken up from lower limb amputation to someone who
is fully rehabilitated. Still in 2017 , the majority of ways that a P limb
is designed , is through a process of plaster casting.
So a negative cast from the remaining limb, turned into a positive mould.
Then a series of rectifications to the shape. Changing in a very strategic way
to get a target load transfer. Below the knee amputation, trans tibial
and posterior view. The prosthetist (Pt) has a few target areas , where they're
trying to load the limb. Feel around one of your kneecaps , the bony kneecap
and then a bit farther down another bony lump, the tibial tuberosity,
where your quad muscles from the front of your leg join
onto your shin. Between those 2 boney lumps , there is a soft
spongey bit, this is the patella tendon where your kneecap
attaches to your tibia. That is a very low-tolerant area
, you can press on that all you like. The pt makes a change of shape
so you can bear load there. They want to avoid bearing load on the
resitual tip of the stump, because that is very sensitive.
A GRP tibia with the load bearing ends are relatively large,
but do amputation surgery , cutting through the middle, the
cross-sectional area is much reduced. So you would expect the
pressure to go up . Also if you feel on the inside of your arm ,
its similar to the skin oon the back of your calf, its very soft and delicate
in comparison to the skin on the palm of your hand or sole of
your foot. The tissue is not designed to take the pressur eof walking thousands of
steps a day. So requires an experienced Pt to do this rectification
process . Take the positive mould and with a file or surform
, remove material from under the kneecap , and then perhapsa tub
of plaster of Paris and build-up material o nth etip of the cup.
Once she is happy witht he shape , she'll try a trial socket.
Polypropolene , still in 2017, a big sheet of it, in a frame, placed in
an oven at 200 degrees until the centre dips a couple of inches.
|Place it over the mould, suck out the air via vacuum, so vacuum-forming
a trial socket. So you can see the indentation that will go under the kneecap.
A square cut-out at the back , so the subjec tcan flex their knee.
Then an ireative process, by which the Pt, gives it to the person its
designed for and see how happy they are with it. Much like snowboard
boots, with a heat gun can make modifications to regions that are too
tight or are not pressing hard enough. The problem is, a lot of people
who have lower limb amputation , from vascular disease, they loose
their sensitivity i n the soft tissues, so they don't know they are
pressing too hard. So we make it transparent , so as normal with pressing
anywhere on human skin it goes white. But people with vascular
disease often loose that response aswell. The result is that in the first year
after amputation the average is returning to your Pt , 9 times.
That is data from across Europe. In the Uk perhaps not so many
as difficulty in getting the appointment. The rehabilitation success-rate
via this sort of process is about 50 to 60%. People with this setup,
have a dilemma , do I tell my Pt there is a problem or put up
with it ,bearing in mind I'd be without my leg during the 7 weeks
of modifications. It seems wrong that in 2017 people are having to
make that kind of decision.
In 2012 I thought, as a mechanical engineer , how could I help
ways around this. I was in the position , many find themselves at uni,
where I have to justify myself into staying there instead of a post-doc
role contract of 18 months if you're lucky. My prof who took me thru
the PhD was an expert in artificial joints . So what other area might
the techniques I'd developed , be useful. What tools do I have that may
be of use. The goto quote , for mechanics, is from Lord Kelvin.
"To measure is to know, and if you can't measure it,
you can't improve it". So how much of what Pts do, is actually measurements
of what they do. Extra data they could take out of the processes they are
using, so at least they have a record of it. What I thought was a brilliant idea,
I soon found others had thought of this also. So CAD/CAM techniques
in Ps. We no longer draw stuff on paper any more . CAM is a collection
of technologies, CNC a lot Computer Numeric Control conventional
machining methods controlled by computer. 3D printing/ additive
manufacturing is the latest. Pts started to develop this in 1980s
and until 2000 until use in any number. The Pt will use a scanner
to capture the shape of a residual limb , digitizing it, create a computer
model , then they can progress the rectification process in a CAD
environment. So the under-knee indentation they can create, and at the
front of the tibia they can remove material away from the limb,
so not pressing on the shin bone. Also the fibula head on the outside
, a nice structure that can be presses avoiding a nerve that passes over the
top of there. They can now make more accurate and quantitive changes to
the limb shape. Then CAM via milling , start with a large polyurethane
block , placed on a turntable and a multi-axix robotic arm with
rotating milling bit, carving out, in theiry, exactly the same shape
as in the design. These robots tend to be in their own room so the
dust generated is not inhaled by the operator. The robot does a rough
machining operation , including a sneeze function , to clear dust.
So I looke d at how we and th Pt could do more with this.
They would use these new processes but carry them out in the same
way as plaster-casting. They'll know the regions they are looking at ,
for changes. While they can make quantative changes, they are still
like free-hand sketches on the limb-shape. So we take an
aquisition, a scan, we could bring in 2 computer-shape files ,
represented as meshes , a series of points or vertices, joining the
points into triangles. The 2 colours represent 2 scans of the same
shape . Then we can do imprecise alignment by translation and
rotation , by hand. Then we can do a more accurate alignment
by iteration of a process called closest-point matching. This gives an
automated process by which we can align the shapes. Being automated,
it is less likely to be subjected to human error, ie I don't have to
be a fully trained technician to use this. You can see different regions with
mor emismatch . If exactly the same shapes, al you'd see was
noise, no mixture. Thena final process called registration where we
map one shape onto the other, allowing a point to point comp[arison
between the 2 shapes, w ecalculate the Euclidean error.
Pythagoras in 3D, RMS in 3D. We need to present the data in an
interesting or at least accessible way. We produce a colour map of the
shape deviation , just 1 colour is slightly higher deviation.
We only have high errors around the interfaces, the place where there
is some human input, so the case for automation.
We used this with a project from archaeologists, comparing different
teeth. A P socket is more or less the same shape as a tooth.
How might the P community be interested in this research.
Were we using the right kit. Same technoique using state-of-the-art
scanner , relatively few NHS clinics have been convinced to use
so far. Its a structured laser scanner , about 30,000 GBP .
Inevitibly a barrier to it being taken up. We are then using something
very technological in clinics compared to something that was very
tangible , manual and experienced based procesing. So we need to
introduce such changes in a sensitive way , so it does not come across
that we are trying to replace the Pt experience and skill. It has to
be a tool to allow application . Such scanners are usually deployed
on automated car production lines , scanning pressed panels for example,
so extremely accurate. So we though we'd try characterising how
accurate. So we 3D printed a test piece, so we had a good idea
of its accuracy, at least we know what shape we sent to the 3D printer.
So colour scale-bar 0 to 1mm , 95% of the surface comes within 0.16mm
, comfortably more accurate than 1mm.
So an Amazon purchase for a 300 GBP scanner, but is it good enough.
Extended colour map now 0 to 3mm and the accuracy is about 1.5mm .
We can see a systematic error, along the length , which is interesting.
We can correct for such systematic errors , but its still imp[ortant to
try and characterize what the error is. At that stage we did not know what
error is important. Prod some soft tissue on your hand , it takes very little
force to move it 1mm, so maybe 1.5mm error is good enough.
Secondly we thought it might help the centres that already
have this kind of technology, to develop best practise in their
limb fabrication. S oafter they've designed the limb , does what comes out
of the fancy robot, actually match the original shape. We can take the
shape we sent to the cutter, we can subract the socket shape that came off the
mould and use the same colour map . We can then see how errors
manifest across the surface, so this is relatively reassuring.
In the concave regions we have a larger surface error, gives some
confidence as the shape is created under vacuum , release the vac and
some of the material will spring back. Around the periphery a "blue"
negative colour, some interference, causing the shape to spring back.
A sanity check - where we put some real physical data into our
computer programme. Also can we try to inform socket design .
instead of telling a Pt how to do it, we can take in large amounts of
data from previously designed socketys, which have achieved a successful
outcome and give them info on what is a good first-guess socket
for an individual.
So an example showing blue , where pressed in under the kneecap
and the red regions where the socket is larger than the limb , where
material is added to bear load. On a population scale we put in a
lot of stats, work just progressed into a recent paper.
What is the effect of the design on the soft tissues. These soft tissues
have to change the job they're doing, between healthy pre-amputated state
to when having to bear full body weight, on the nice soft skin that
was on the back of your calf, not used to bearing any load.
How to change the tissue for this new job, to become more durable and
tough. Like learning to play guitar and callouses on your finger-tips.
With that , if painful, you can leave the guitar for a few days and then
pick up again , but not really an option here. Any pus ein the
rehabilitation process affects other aspects.
So if there is different prpcesses adopted by Pts , can we put some
evidence-base behind the design process.
3 design processes a Pt might consider
The Total Bearing Socket TSB, very little change between socket
The Patella Tendon Bearing, particularly relying on the press
fit withthe bearing surface under the knee, we make focal changes,
technically more of a demanding socket to create.
Not used so much these days KBM socket from the 1990s , a German
name. Some marked press-fit regions above the knee, grips the limb
side to side, a much more bulbous shape around the residual limb.
So we can describe these shapes by looking at the outsides of the limb
and the design of socket. We can use imaging to try and understand
what is happening insode the limb, how the socket is being
reconfigured by the socket design. Using MRI scan slices , showing
ups contrastining between different soft tissues. The bones, residual tibia ,
femur and knee cap, tendon , the layer of skin and some of the
muscles , some calf muscles wrapped around the end of the limb
and sutured onto the front and the fat-pad on the tip of the limb.
So well established amputee where the muscle starts to atrophy
, as not used in an established way, and transforms into fat-pad.
We can see the marks of the more marked rectifications in a couple
of cases. The KBM socket has manipulated the soft
tissues to move upwards and backwards.
Then the triangular shape of the PTB socket , pressing either side of the
shin so we dont load on the shin. There is very little change of shape
to the vacuum formed.
So taking measurements to see what those changes of shape actually
cause. Unlike designing a piece of Aluminium airframe, that has been
heat-treated the right way , we can say wityh a great deal of confidence
when it would fail. A lot of mechanical engineering is structural and stress
analysis . We know hte stresses, compare to the material strength
and know if its strong enough. Soft tissue material vary dramatically.
Vary person to person . Just because something does not actually fail,
doesn't mean it will be comfortable. Some people have a diminsihed
sense of what is comfortable, and these people may be the ones we
have most concern about, in having soft tissue problems.
So we also take a series of biophysical measurements, to understand the
effects on the residual limb in compression and shear, in terms of changing
tissue oxygenation for example. And inhibiting the lymphatic flow,
the way waste products are removed from more distant tissues away from the
body centre. We just today submitted our ethics application
, as even just self-experimentation , it need ethics approval.
So as an engineer , who else migth be interested in such techniques.
This is a global problem . There are predictions that by 2035 there will
be a half billion people with diabetes worldwide, disproportionately
affectring the developing world . 100 million people worldwide need some
sort of Pt device , and 90% of those don't have access to the services
providing them. The access problems include lack of funding
and infrastructure and also personel training. Finding certified
Pts to provide these limbs is a real challenge.
We went to Campodia, somewhere infrastructures that may be
starting to be in place, and be at least receptive to what we have in mind.
Could our crazy ideas be useful. Between 1975 and 1979
about 1/5 of the population diesd in genocide . The polpot regime
determined that the population should return to their agricultural
origins , closing down all school, universities and hospitals/.
The borders with Viet Nam and Thailand were covered with landmines , to
stop the population leaving. Not just the people trying to cross
the borders but also the soldiers patrolling the borders, ended up with
lower limb amputations. So homebrewed peg-legs , very basic,
but people wearing them every day. Even the soldiers , the majority
prior to Polpot, had been agricultural workers. Once they wer einjured
they had ro return to agriculture, trying to work with 1 limb or even both limbs
missing. So not just walking the streets but working in padi-fields
for 12-14 hours a day. In 1990s the Cambodia trust was set up
, providing Pt limbs to anyone in hte country free of charge.
A Pt broken at the angle, held together by tape, turned up
a tthe clinic , and repaired and he returned to the very physical work.
They are all produced by a Red Cross unit in the capital Pnom Pen.
Standardised limbs , example passed around. So someone is injured, they
have medical treatment, they go home to a different part of the
country to convalesce with family . So you take your Pt with you
and can then walk into any clinic and have components replaced,
there and then. All the brown polypropelene components
of the limb are completely recycled. The condition that allows you to
take away a new limb with you , is you leave your previous one withthem.
A large box at the rear of the factory with a lawn-mower engine on the
side , and a blade inside. It turns the plastic back into granule size pieces
that can go straight back into the injection moulders, for new ones.
Nearby is the artificial leg and rubber processing company, 12 grandchildren
and grandfather produce 500 Pt feet per week, the foot on the
limb passed around. These Pt feet have proven to be the strongest available
for use in a rugged environment. They start with various grades of
synthetic rubber , in shhet form. Roll them on a table and produce a
pre-form , then an injection moulded nylon heel , and the rest from sheet
black rubber . Then squares of more flesh coloured rubber , around the
outside, placed in moulds and placed in an oven, then tidy up the edges.
This process runs continuously . 500 a week produced by just 1 family.
The first challenge is funding. One of thesePt limbs does not do the
job for the rest of your life. In the UK its estimated at 1000GBP
per year for a single limb repair and replacement, for the
rest of your life. If you have govt or national funding , then economics come in.
For a given pot of money its better to fund road safety measures, as now a lot
of the minefields in Cambodia have been cleared, the main way people
ar einjured from road accidents. Road use is increasing dramatically
and exceeds the infrastructure in place. Peole doing agricultural
work , the money they earn today, is spent on food for tomorrow.
They can't simply take 2 or 3 days off work , to go for treatment
at one of the 11 clinics across the country. There are many there who are
completely unaware that Pts are available and schemes in place.
Even medical doctors can be unaware of the services available.
There is a clear difference between what is considered medical
and what is considered disability. So can some of our developed
techniques advance the access. So would the 300 GBP scanners be
sufficient to characterise the shape of the residual limb. So why
are we talking about this extra cost when a sack of plaster
can be bought for next to nothing. The Arts and Humanities Council put a
nice statement together on this , which summarises a lot of past
experience. Many scientific and technical interventions
continue to fail, due to a lack of understanding of the social ,
cultural and historical contexts and their likely reception
be th e people they are intended to benefit. Some notorious
examples of this- The National Formula milk scandals from the 50s/60s,
where people sent formula milk to Africa. Then people were unable to produce their
own milk , to nurse children. When the formula project ran
out , there wa s a famine. More recently some of the ways the
Ebola outbreak was managed, without consideration of some of
the cultural , social and traditional aspects that were very important .
So we have to make sure, that just because we have a bit of tech that
works in the UK, and if we find a funding for other parts of the
world; it doesn't do more harm than good.
A lower and middle income issue , in general. We try to take an inter-
disciplinary approach to understand what the requirements are ,
in other countries, without making assumptions involving what
we have access to. Also sustainable business implimentation.
Tools and spare parts have to be considered. We have the mechanical
engineer, the physiotherapist for the scanning, a health-care
psychologist a qualitive researcher. I was trained as to being
purely quantitive . Its a process of understanding what people
really need, as a mechanical engineer , I never saw that aspect.
Also an entrerprise fellow , in the faculty of health sciences,
who understands business modelling techniques , how a business
case can be built for this kind of tech.
We are in Soton, how do we test any ideas with the people who
really matter. So we work with the International Society
of Prosthetics and Orthotics, and also th eCambodian School
of Prosthetics and Orthotics. The first fully certified by ISPO
asa training school in SE Asia.
(Orthotic are an addition to assist the body like hearing-aids Orthopedics are
replacing missing parts of a body)
They now train the whole sub-continent , who end up in Africa ,
the Pacific Islands and across S America. These people have the
influence to implement ideas, we eventially came up with . are
actually workable. We've been able to answer questions that
we could not ask in the UK.
The casting process, the most important element is the Pt
thumbs. He identifies the regions around the knee, around the
patella, the tendons. When they are roughly confident about the
shape , they press either side of the patella tendon with
their thumbs. Blinking between the 2 images , you can see the
shadow created by the thumbs. They are already rectifying
the socket , when they are taking the original cast
when the plaster is still wet. When they take the cast off
and lokk inside , the residual limb is covered in
cling-film , they draw around the regions of interest with a felt-tip
pen , which transfers to the inside of the socket.
A human very much involved in this process , so whenever
we have a human, we probably have some variability.
A question answered in Cambodia, not available in the UK,
just how repeatable is the casting process.
So 2 clinicians taking pairs of casts of a small group of volunteers.
So pairs of nominally identical casts . We feed them into our
shape comparison system. Repeat casts of the same person ,
done one immediately after the other . We can start to see the 2
thumb-prints , rendered blue in the images. Then we can see the red
zone where material is added on the tip of the stump.
Also the red stripe down the front where we've added material
, pressing on the sharp edge of the shin , the bit that hurts when
banged against a table. So does someone get the same result, one time after the
othr. So answering the fundamental question, how accurate do the
scanners have to be. How much do we need to spend on them.
So this is being used now in a couple of projects in africa .
Its important that the Pts tell us the reliability of the tools they've
been given . These results are hot off the press.
So is there scope for these technologies in Cambodia.
In the small local market selling chickens and edible tarantulas,
a booth selling second-hand mobile phones. So you can buy a
reconditioned Iphone, for 1/4 the cost in West Quay.
Their technological development bypassed the dial-up
period we went through. They've gone straigh tto 4G connection,
they've got beeter 4G than I can get in my house
200m off a main road in the UK. So access to data , via
networks is far better . So we are trying to develop appropriate
data technologies around Pt and orthotic processes.
The interesting word is appropriate . The limb I passed around is
what I'd call appropriate tech. Its not the most advanced Pt limb
in the world , but it is appropriate to the communities in Cambodia.
So scanning systems that collect the right amount of info ,
ways of presenting it in the right way, feeding info back to the
users . You can often now connect the 300 GBP scanners to your Iphone
, certainly to an Ipad, transmit it back to the Pt clinic.
They can transmit back to the user on their Iphone, the info
for care of the residual limb tissues, how frequently they
need cleaning, and the socket. How often is too often to be cleaning.
Reminders about the rehabilitation process, via audio and
video demos. Tell them how to repeir their own Pt limb, so they
don't have to take 3 days off and return to the clinic.
The charity does reimburse people, loosing work , to have to
return to clinics. Techniques like this might prevent them having to
return to a clinic 1 time in 3, an enormous improvement.
We're not just looking at the technologies , but also ethnography ,
human factors in what people need and need to understand.
Courtesy of EPSRC , 1.5 billion nationwide towards
global challenges research funding , which includes the work explained
here. We've applied for some mor efunding, so diid 140 other
groups and they expect to fund 6 to 8 projects.
Acknowledgements to colleagues and students, collegues at
the Fraunhoffer Institute , Germany who wer e part of the
MRI study , part of a much bigger study . The clinicians
and participants in Cambodia .
If someone has had an amputation , do they ever add a
prosthetic that protrudes out of the body?
Dental implants is an area where thry have the same challenge.
So we use the the same process called osteo-integration , directly
to bone, used for knee replacements for a long time.
But you have something that goes through the skin, a wonderful
environment to cultivate bacteria and other things.
The dental implanters were the first area to try that. A 19%
infection rate, not just superficial skin infections but
nasty deep infections. If we had a 19% infection rate we'd
be in great trouble.
I thought it would be a good way of taking a lot of the load?
Yes that and the feedback. A lot of the challenge in the rehabilitation
process is the feedback , back from a prosthetic limb.
We have limb position awareness without having to see them.
Being able to sense where or where not a prosthetic limb is,
is a problem.
Connect directly to the skeleton and this feedback is very good.
Your skeleton adapts to load change , as well as the muscles.
Why the astronauts on the ISS lose some percentage of bone
and muscle. If you get an unexpected load, say fall over sideways,
bone is not adapted for such loads and get a fracture in the bone.
I met a boxer with a pair of osteo-integrated limbs and he carries on
doing boxing training
Does the phantom limb integrate with the prosthetic limb
The osteo-integrated process has allowed that. I was at a 2013
conference where they presented the first surgery , upper limb
prosthesis control. We can control a hand movement by
EMG sensors electrmyography, electrodes over the muscles.
You retrain the muscle group , that otherwise are no use becaus eof
the amputation . Stick the electrodes on the outside of the body
and use for controlling opening and closing the prosthetic hand.
If you go outside in the cold or the humidity rises the sensitivity
reduces and tendency to loose the control. So sensors are placed
inside the body. Still a relatively small number of people
I previously thought the matching process between the stump
and the prosthetic would be arranging so the pressures were
evenly distributed over the interface, but I gather that is not the
case. Not necessarily maximise the pressure , but increase in some areas and
decrease in other areas?
There are competing scjhools of thought . There is a further method.
The scanning and plaster casting techniques, the big diffwerence is
you are capturing the shape of the limb when its not under any load.
So things will change as soon as it bears weight. So there are some
clever, relatively simple tools . You can vacuum cast or sand cast the shape
while bearing the load of a dustbin of sand .
Is there anything coming from the area of animatronics , remotely
moving jaws and eyes etc for filmic purposes , but brought in to this.
Say someone is going through digging movements, then you can remotely
adapt , via pneumatic systems , when in the right place then lock it
in position. Then go through the casting process?
People are looking at adaptive sockets with sensors that can
change the stiffness, depending on the amount of load.
That is in a final socket, they are things the industry is working on.
Concerning the accuracies of the different technologies and you
get different results , if you have a subject who walks straight
in from the coldcompared to someone who has been sitting in the waiting room
for 15 minutes.
Is that a repeatable change, different people going throught he
same change of environment would have the same reaction?
Too many variables. From an experienced prosthetist, concerning a
subject with 3 new limbs produced, they compensated for limb loss
by adding socks t othe gap. So prosthetists talk in terms of
number of socks. With each of the 3 limbs , they needed 4 socks to
manage the pressure. So what was going on. They had diabetes and were on
diuretic meds. He lived a 3 mile cr journey from the centre, so they
did not take the diuretic before getting into the car, so they were larger.
So mechatronic control , to get the socket to adapt to the
limb. That is the area for people with very expensive private
healthcare. Thats where a lot of the exciting engineering seems to
happen . You can spend 30,000 on a limb but if the socket is not
Is there a system, not strain-gauges as such , but a mesh of perhaps thousands of very small-resolution strain elements on a flexible membrane , that can form into
the 3D shape. Place that in the interface and remotely monitor with the
subject walking or jumping, sitting or standing-up from sitting or whatever?
This was in a PhD paper only last week , so I'm not allowed to
say too much, but it comes down to how few "strain-gauges" you need for the
result. We as engineers would be comfortable with htat , but not so
a prsotheticist. So how to optimise the amount of data that comes out of such
as that and how you present it to a busy operative.
There are adaptive polymers that change their stiffness, according to the amount of current passed . Or sockets made of 4 or 5 arms , then webbing straps with
tension bands , that controls the bulk stiffness of the socket.
But the sensing inside , and whento change the settings , is the complex bit.
Are these fabrication techniques being used in our local hospitals or are
they just very specialist centres, are the scanning techniques readily available now?
Theya re starting to get some momentum . The techniques were developed
in the 1980s , but only mid 2000s did they start being used in real numbers.
A lot of prostheticists see this as getting a worse result much faster,
so a lot of training and a learning curve. Also a sense of threat, jobs replaced
by computer. So if I know I can get a pretty good result by plaster- casting
, from doing it for 20 years , why would I put a lump of
tech between and achieve a result of unhappy clients for 3 months
until we can sort out new problems. One of the ways we think we can use the
emerging data is to soften this learning curve. Help people to understand
how one process they did, went well and another thing they did , was not
successful. Most of the clinics in the UK are starting to
have one of these scanners. Many send the scans to a fabrication
company. So I'm involved with seeing now accurate the scanners are,
what amount of accuracy is required and what is good enough .
Wouldn't it be better to have the subject on a turntable , and a static
scanner , rather than hand-held, keeping constant distance and reducing the
variables before autostitching the images?
Yes. One of the early scanner versions was a halo with 7 or 8
cameras around it , moved over the limb. These single scanner units have
caught on though. The autostiching is done on the laptop that
powers the scanner, no requirement for greater processing power.
My first PhD student looking into how to get it to work on an NHS laptop.
A lot of the things we were doing would only run on a supercomputer
, greta for us in getting published , but ultimately our work
must result in something clinicians can use.
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