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Steven Collins: New prosthetics should be better than the real thing

Steven Collins: New prosthetics should be better than the real thing


(bright music) – Today on the Future of Everything, the future of prosthetics
and exoskeletons. I have an uncle, Uncle Ron, who lost his leg when
he was seven years old. It was in a driving accident, and in addition to
wearing an artificial limb for his entire life,
including to this day, as he’s around 80 years old, Uncle Ron devoted his life to the creation of artificial limbs to help
others with the same challenges. I remember him moving
for a couple of years to the Fiji Islands where he
trained folks in how to create, this was in the 60’s and 70’s, create artificial limbs,
usually made out of wood. I remember his frequent visits to Vietnam, and other areas where
war had left land mines, which continued to take
their toll on civilians who accidentally set them
off, and often lost legs. I remember very primitive artificial limbs that he showed me in war
in the 60’s and 70’s. They had cups for his thigh with padding, that were clearly there to try to make it a little bit more comfortable. I remember leather
belts for attaching them as securely as possible
to his remaining leg. Very crude bending at the knees. I can’t even remember If there
was bending at the ankles, and there was always an issue of, and for a young boy this
was what I remembered best, the matching shoes. Uncle Ron always had one shoe
that he wore on his good leg, on his foot, and then
he had the matching shoe that he would strap onto
his artificial limb. And for a little kid, that was one of the most fascinating things in the whole kit and caboodle. And it was amazing to
see my uncles facility with walking and activities of daily life. This really did go into the background, even though he must have had a discomfort, it was never apparent to me. And it was just my uncle. He did tell us about phantom limb pain, where he would have
pain in parts of his leg that didn’t even exist
anymore, and itching. And he said actually the
itching was even worse than the pain in many ways. And this all points to the complex relationship between the brain, the limbs, and the nervous system. Well, now we speed forward, and there’s been a
development of new materials. We have robotics and
software, we have methods for fabrication of prosthetics,
and even exoskeletons. Which we’ll hear more about in a minute. And even these have advanced markedly. And there are expanded uses. Now we’re not just talking
about the loss of a limb from trauma, but we now
have patients with stroke and the inability to walk,
and other neurological and muscular diseases. Well Steve Collins, is a professor for Mechanical Engineering at Stanford. He has pioneered new methods for designing and deploying prosthetics and exoskeletons that simultaneously train the human in how to use these devices,
as well as the device to kind of compliment
the human’s capabilities. To harmonize and reach as good a functional capacity as possible. Steve, what do patients today experience when they
need a prosthetic device, and how far have we come in terms of providing them useful
devices that allow them to just function in their
personal and professional lives without having this be the biggest deal? – Sure, hearing about your
uncles story is great, and I think a lot of things are, there’ve been improvements,
but there are a lot of features that are really similar today. So people still have this padded formed, we call it a socket, that
goes on the original limb. – Socket yes.
– Yep. And that provides some
mechanical connection to the leg, and we now use carbon fiber mostly, and better polymers, but
it’s still trying to do about the same thing. And we now use vacuum suspension to sort of suction cup action
to keep if from sliding down. – Yes, makes perfect sense. – Instead of those leather
straps which is nice. – I do remember some of
the woodwork on these legs was spectacularly beautiful,
like when they made a fancy one, it was beautifully
varnished and stained, and it really was like
a little piece of art. Which may have fallen by the way side, but I do remember that
they were spectacular. – Oh yeah, that was a big component of early prosthetic limbs. One of the biggest suppliers
was called Ohio Willow Wood. Advertising the kind
of wood that they used in forming their limbs,
we collaborated with them when I was a graduate student. But many people do, and
I have a similar story from when I was a kid, I was much younger, but I met my great uncle, and I was a impetuous 8
year old or something, and my brothers and I asked him, what happened, how did yo ulose your leg? And he did this great thing, he said, “I’ll only answer one question. “I’ll tell you, but I’ll
only answer one question.” We said, “Yeah, okay.” “It was bitten off.” And he left it right like that, which was fantastic that
really stuck with me. Meeting him and learning
about his experience. – Was that true? – No (laughs). I presume not, I don’t know. He only answered one question. – He answered the one question. – But actually no, I think
he lost his limb to diabetes. And also, as it happened,
I didn’t know this sister at the time, but he became
really involved in research. And was a frequent
participant in experiments at the University of
Michigan, where I grew up. So anyhow, things have come a
long ways in many dimensions. Especially with interfacing with the limb, but the basic function of
the a prosthetic foot say, is still fairly similar to
the device that you described. And many people are prescribed a solid ankle cushioned heel. It could be made of wood, or polymer. There’s some padding on the heel, and people who are more active will get something that’s
shaped carbon fiber. So it’s more springy, but
these are passive devices. So they don’t have the
ability to do active work like our muscles can do, and
they don’t have the ability to respond to our behavior
and the environment, and change how they react to say, help you to power your way up stairs, or walk faster or slower, or recover from a little disturbance
like a bump in the road. And those are the kinds of problems we’re trying to address. – Yes, and it sounds like even not knowing very much about it, it
seems like there are technologies that if appropriately used, could help in those areas. And I’m sure that’s
what you’re focusing on. – Yeah, absolutely. We think so, and so our group is one of, now maybe dozens of research groups across the world that are trying to incorporate these modern
robotic technologies into prosthetic limbs that
have more the function that we’re accustomed to
from our biological limbs. So enable us to walk with less effort, and more quickly, and with better balance. Which are all big problems for people with amputation and stroke. In fact we think, that because
of some of the advantages of robotic devices compared
to the biological system, there are a lot of disadvantages, but there are some advantages. We think it’s possible
to make robotic devices that enable people with disabilities to outperform people who
haven’t had an injury like that. – Right, so great, let’s
do some definitional stuff, because I jumped right into it. But prosthetics, I think
most people understand a prosthetic, I was describing
the artificial legs, and there are arms. Tell me about exoskeletons,
and then we’ll go to what the potential use
cases are for these, and then we’ll talk about
where we are in this process. So exoskeleton. – Sure so, you can imagine
something from a Scifi movie, and that’s kinda the
direction we’re headed. So the most popular vision of this would be the iron man suit. – I was gonna ask about that, but I didn’t want to seem like a fool. So thank you for brazing it yourself. – No, I think they capture the sort of, bold vision of exoskeletons that could, not only help recover some performance, but maybe extend your abilities beyond what comes naturally. And I guess this is on the continuum with the kinds of devices
people are currently prescribed. Which we call orthosis. This is some molded plastic and metal that wraps around your existing limb, and tries to help say,
provide more stiffness at the ankle joint to avoid say, dragging your toe if you have a drop foot or something like that. Or help keep the knee bending the way that we want it to bend during swing. The swing phase of
walking, things like that. But there’re relatively
basic technologies, and they can’t add power, they can’t respond to the environment. And so we’re trying to
add some of these features that we think are really
helpful in human performance. – Got it. So I can think of the
exoskeleton as kind of a descendant of the orthotic? – Yes. – Where we’re adding some
energy and capabilities. – A powered orthosis is what
people called it originally. – I’m sure the applications
range from helping people who have had injury, but I’m sure it also could be in the kind
of the Iron Man thing. Taking people who are kind of perfectly able to under normal observation, but giving them special
industrial strengthed capabilities for industry or entertainment. – Yeah that’s right. – So are that full set of
application kind of in range? – Absolutely.
– In your work? – Yes indeed. So the thing that gets
me up in the morning is the idea that we can make devices to help with disabilities. That’s my biggest motivation. – That’s the alfa. – Absolutely, but it’s really hard, and so a lot of our early work has been with people who
don’t have a disability. Able bodied folks. Mostly college age. – Healthy volunteers.
– Healthy volunteers. – They make the world go. – Exactly, and this is where we’ve had our biggest breakthroughs and progress so far. And we do work with the
military also with the Army, who are interested in preventing soldiers from getting injured when they carry lots of body armor out in the field. – These packs can be 50 to 100 pounds is my understanding. – Yeah, it’s ridiculous. – And even though they’re young men, even though their young men, this can still take a toll. – Oh yeah, absolutely. It’s a huge problem. – This is the Future of Everything, I’m Russ Atlman, I’m speaking with Professor Steve Collins
about exoskeletons, orthotics and prosthetics. Okay so we have this full range. You’ve become well known of this idea of human in the loop, as
a way to kind of implement a new orthotic and
prosthetic technologies. Tell me what that’s all about, what’s the new idea there? It sounds like humans
should have been in the loop all along, but maybe they weren’t. – Yeah, well I guess they were, but we maybe weren’t
really incorporating that into the design process. So this is a popular topic right now, and last year there were
about 5,000 paper and patents in the area of powered prosthetic
limbs and exoskeletons. And it’s been in the popular
imagination for a long time. The media, that we’ve talked about, but to date there’s been
only five or 10 devices that have demonstrated about that. – I mean there was guy
who kicked a football at the world cup a couple years ago, and that got a lot of attention. – It did absolutely, but… – But almost proving the point that this was not really ready. – Right, exactly, right yes. I think that’s a good illustration, right. So where we think the technology an be is much farther from
where it is right now, and so we think that the reason that we’ve been making
relatively slow progress, despite huge and vast but big
groups of very smart people, is the design approach we’ve been using. Which has been to first use our intuition, or observations of some
aspects of normal movement, or simple models to make a prediction as to what the device should do. And then we spend a few
years making something that can embed that functionality, and then we finally get around
to testing it on a person, and it doesn’t work. Almost all the time. – And does not work. Can you unpack that a little bit for me? – Sure.
– Is it, it doesn’t do as specked out?
– No. – Or the patient hates it,
or something in between? – Yes, people often are very excited to try out the new
technology, but after a while, maybe aren’t as thrilled about it. But no, it performed the mechanical, or robotic function that
it’s designed to do. – Right, ’cause you guys are good, and you’re engineers you know how to build something that you’ve designed. – Absolutely, we’re really
good at that probably now. We’ve got fantastic technology,
CAD and simulations, but what we’re really bad at, is predicting how the
person is gonna respond. And so we think that is
the crucial challenge I developing better assistive devices. Is we need to get a vaster assessment of how the person responds,
and involve that response in the design process itself. – Is the hypothesis
that it will have to be at an individual level,
that different people will have different
needs, or do you at lest have some hope that if
you involve them early, you’ll get a somewhat generic
solution for multiple people? – I think depending on the population, it could go either way,
we just don’t know yet. So we’re trying to address both the problem of finding something that works for lots of people, and figuring out how to
individualize something to customize it to an
individual persons needs. – So can you tell me a story about kind of a story of a human in the
loop kind of design effort that kind of worked or
looks like it’s gonna work? – Absolutely, so in our lab we developed some exoskeletons that help
your ankle joint during walking, and for the first four or five years in the group we tried lots of different hand tuned controllers,
and we saw modest benefits to the users improvements
in the efficiency of walking that was our target, of about six percent. – So the person has some sort of deficit in their ability of their ankle? – Well these are again. – These are normal. – We’re starting with healthy controls. – Okay, so you’re just
trying to get them to walk more efficiently, so they
could either do it longer or faster or whatever? – Yes.
– Okay, so that’s the goal. – Exactly, with the
expectation it’s a good extent. – And you were doing
these tuning exercises which were not panning out so much? – Not going great, no.
– Okay. – We saw some small benefits, but much smaller than we thought possible. – You said six percent. – Six percent improvement energy. – So just help me, would
I recognize a six percent change in my efficiency of walking, or would that be in noise of like… – Oh no you would. An example I like is the
use of your arms in walking. So if you watch people walk, they have this characteristic
arm swing right, that where your right arm
moves with your left leg. And why do people do that? Well one reason seems
to be to save energy. It actually saves you about eight percent of you metabolic energy. – Now there’s a good number. So that helps me
understand the six percent. – Right, it sounds like a small number, but yet you walk people walk, they all swing their arms like this. – And if you try to
walk without doing that, which we’ve all done as
a kid, it is very hard. – Yeah, so if you put your
hands in your pockets, you can do it, you look cooler, right. But you expend more energy. So you can watch people walking, and see how often aesthetics
win out over economy. So anyways, these small differences do seem to affect peoples
behavior five 10 percent. – I’m sorry, so I derailed you. – No. – You were telling me the story, but so six percent is roughly the benefit you get from swinging your
arms, little bit less? – Right, compared to keeping
them in your pockets. – Gotcha, okay. – But we thought we should really be able to do better than this. And that’s when we started
developing new techniques for human in the loop optimization, where we would measure
the persons energy use while they’re using the device, and then we’d feed that
information back to this optimizers algorithm, that would then try different behaviors of the device. Different ways the device would move. – Like tighten up a bolt,
or give a little push at a certain point?
– Exactly. Like when does it push you,
and how much does it push you. We talk about it in terms
of these patterns of force, and torque at your joint. And so you walk with this optimizer, every couple minutes it would change the way the exoskeleton pushed on you. And after about an hour, we
found that optimized assistance improved energy economy by 24 percent. – So four times more. – Four times bigger. – And that makes perfect sense
is that you’re now watching, you’re doing little mini experiments on a minute to minute basis. You’re getting feedback, and then you have the algorithms and obviously
I’m sure you’re using AI, and the modern computation to say okay, we’re gonna tweak the variables. And that is a personalized
kind of prescription, because if you put another
person in that same, I’m guessing, tell me if I’m wrong, in that same device, they
might benefit from the settings from the previous person, but you have a further ability to tweak. And is that what you’re seeing? – That’s right. We’ve actually observed in an experiment, something that makes walking easier for me can make it harder for you. So it depends on the population and the kind of intervention, but you can use this process
both to identify things that are generically
good for lots of people, and ways to customize to an
individual persons needs. – And so that’s a great example. This is what you mean when
you say human in the loop, and this sounds like it’s the future for, you design a generic solution,
and then you tune it. Which raises a whole bunch
of questions that we’ll get to in the next segment. This is The Future of Everything, I’m Russ Altman, more
with Dr. Steve Collins about prosthetics, orthotics, exoskeletons next on the SiriusXM insight 121. Welcome back to the Future of Everything. I’m Russ Altman, I’m
speaking with Steve Collins about exoskeletons and prosthetics. So at the end of the previous segment, you made a really interesting comment that even for people who
don’t have any disability, they have differences
in what makes them more energetically efficient in walking. And that’s interesting
cause I’ve heard also that somebodies gate,
the way that they walk, is almost like a fingerprint, that AI systems can use it
to figure out if it’s me, or not me, because I swing
my arms and my legs go out And I believe that,
because I look at my kids, and some of my kids walk the way I do, and some of my other kids
walk the way my wife does. So what is known about
the individual dynamics and physics of walking,
and how much variability there is, even in the normal population? And does at affect your work? – Oh sure. Everyone’s different,
everybody’s bodies different, and our nervous systems are different. So as you suggested, you can tell a person by their kinematics, by
the way their body moves. And that affects how
you need to assist them. And so we see that if we
customize our devise to, even healthy controls, you
get more of the benefit from the device. But the benefit’s even
bigger in populations where there’s more heterogeneity. Like people who’ve had a stroke, it affects everyone really differently. Or an amputation, the
places you might have pain, how much residual muscle you have, it’s different across everyone, and so we expect even bigger benefits if customization in these
more diverse populations. – And I don’t know if this
question is too nerdy, but you talked about that 24 percent that you got to with the tuning. If I took that tune system
and put it into somebody else, they probably wouldn’t
get the full 24 percent. How much of it would they still benefit from the tuning that you did
on person A for person B? Forgive the nerdyness. – Oh not at all, no. That’s a great question. So that study I described to you was sort of this break
out experiment for us, and very exciting for us. And we’ve since been following up with lot’s of additional experiments to probe these kinds of questions. And it looks like if you take the average of the best assistance
profiles for 10 people, and you give it to a new person, they get a lot of the benefit. Maybe, on healthy
controls, maybe 80 percent. Something like that. – It’s the 80 20 rule again. – Yeah exactly, yeah., totally. And so if you really
wanna maximize performance you need to customize. – But that 20 percent is worth while. It’s worth the extra effort perhaps. – In some cases. So I think what we’re seeing is that if you wanna make a commercial product that’s widely available
to keep costs down, and to make it easier for a person to use, maybe you wanna go for that 80 percent. – Gotcha. – So you do a lot of upfront development, and figure out what’s the, which this is still a hard question, what should the generic device look like. But once you have that information, then you can create these
customized products, and then mass produce them, and keep the costs down, and
actually reach a big market. – Cool and I wanna end
with, when are we gonna have this I our stores. But before that, tell
me, this has been great, and we’ve jumped into a lot of things, but I wanna step back, what are the application areas that you see? You said that health
drives you in the morning. – Yes. – What are the big areas where you see this can affect thousands
or millions of people, and improve their life in terms of the application areas for this technology? – Sure, so first we have people who really need a device like this, but it’s a smaller population. People with disabilities
like amputation or stroke. We also have people who really need technology like this
because of their occupation, like soldiers, other people who have to, you know, rescue workers, firefighters, carry heavy equipment, go long distances, need to keep going, high injury risk. And then for people that
might use them for recreation. Like say runners, we have
a collaboration with Nike, and you can imagine
different ways in which this kind of device could
improve peoples lives. Through consumer products, and that could reach a huge audience. – Right, so there’s the three big groups, and within the health, I guess because of the aging population,
stroke becomes a more and more important application. In terms of numbers, what
parts of a healthcare have the biggest need for this? – Right, stroke is a huge population. Millions of Americans
per year are affected, and amputation is still
hundreds of thousands of people have an amputation. – And then I’m sure there are these dysmyelinating and neuromuscular diseases, you know, Multiple Sclerosis,
and Lou Gehrig’s Disease where these people could also
benefit greatly from these. – Yes, it’s tens of millions of Americans that could benefit from that. – This is the Future of Everything, I’m Russ Altman, I’m
speaking with Steve Collins. So great, I wanted to get
into those application areas. I know that you’ve done some work where the human is not in the
loop, just robotic walking. How does that interact
with the human in the loop part of the lab, is it
that by understanding movement better, it’ll inform your work, or is it a separate interest? Where does that all fit in? – Yeah, so actually my walking robot work was very early in my career. It was as an under graduate student. So I was at Cornel University, and I had this fantastic teacher, in a Dynamic course,
name was Andrew Arina. And he showed this video of this passive dynamic walking robot. Said this is a system with no motors, no computers, and walking
is just a natural movement of the systems like a pendulum swing. – So it must have been
down hill, am I right? – Down hill yes, exactly. – Because other otherwise we’re talking about perpetual motion. – Yes.
– Okay, so down hill, but then no motors.
– But no motors, right. And so I got involved in this passive dynamic walking research, and then my big project there was to add a little bit of power to allow
it to walk on level ground. Very, very simple primitive stuff, but it resulted in a really
energy efficient walking robot. Similar cost to go a certain distance per unit in mass, as people. And that was a big thing. – So can people Google
this, cause I’m sure everybody wants to see this. If I did Google it, does
it look familiar as a walk? Like is the solution that the robot found, or that you found, or
that your mentor found, does that look humanoid,
or is it an entirely different way to go forward? – No it looks surprisingly natural. Like a person walking. At the time, we argued that it looked more natural than some of the
powered robots at the time. Bos-an-ed-Alex- Alice looks
pretty great these days, but this was 15 years ago. The passive movement of the body really it’s surprising how similar it looks to how people move their body, and it suggested, and still suggests that using those passive dynamics is part of what makes a
persons get efficient. – And it’s not hard, as
somebody who’s a geneticist, it’s not hard for me to imagine that after a few hundred thousand, millions of years of evolution, we woulda had a solution for
walking that is extremely energetically efficient,
and it sounds like you’ve shown that pretty much,
almost empirically. That it’s a very good
solution, if not optimal. – Yes, there’s a big area
of research in the field, and it looks like people
are doing pretty well. – Okay, so I wanted to ask about, so you’ve gotten us all
worked up in a lather about these technologies,
where are we in terms of having them be
available for all of those three compelling application areas? How is the industry looking,
what are the big challenges? What needs to happen? – That’s a great question. So I think that the way’s
you could see this technology getting out in the world
are with the design and prescription, and training
of these kinds of devices. So just coming up with what
kinds of characteristics the devices should have. That’s a research and development thing. Some of it happens in academia, maybe some will happen in industry, and at the stage where you actually receive one of these devices, you can imagine kind
of the way that you get your glasses prescribed. There’s this big system, and
you try different settings, and see what works best. And so we developed these
systems we call emulators. That are kind of like this VR system for physical devices that gives you feel of interacting with an
exoskeleton or prosthetic limb without having to build it. And then you can make a
few changes in software, and it feels like you’re
using a different device. So you can imagine going to a clinic and strapping this on your leg, and then the prosthetist is tuning it. – Yeah the eye glass analogy
is a really compelling analogy, because that is a huge machine that turns that into a very
simple pare of glasses, and you’re having a similar model now. – Exactly, and we think this could result in people getting devices that are much more effective for them. – And actually, again,
really technical question, not even technical but,
are these gonna be huge? These exoskeletons that you see now are these huge things that I would need a garage to keep it in. I’m sure that people in
your field are think about what is the minimal size that we need to generate the forces,
generate the motors, and be kind of compatible
with life as human. – Absolutely.
– And how is that going? – That’s a really important
direction for the field, and looking out five years,
that’s our main focus. Is taking, once we know what
these devices need to do, distilling that into a cheap
and very energy efficient devise so that lots of people
could get access to it. – So it sound like, in
addition to all of this, you guys are fans of
material science and power. Batteries, stuff like that, because you’re gonna need these things to be as miniature as possible,
and as strong as possible. You know, carbon fiber, whatever. So this, it seems, would
be a critical component of this emerging industry. – Absolutely, we follow those
developments very closely. And also, new actuation technologies. New ways of converting that
energy stored in the battery into mechanical power on your leg. – Because you don’t wanna take a hit in terms of the energy conversion from electricity to mode of force. – Yes, electric motors are great, we an do a lot better, there’
still pretty heavy, and bulky. – Thank you for listening
to the Future of Everything, I’m Russ Altman, if you
missed any of this episode, listen any time on demand
with the SeriusXM app.

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