An Open-Source Approach To Better Prosthetics When Marine engineer Jonathan Kuniholm returned to his industrial-design shop after a tour of duty in Iraq, one of his first projects was personal: He wanted to improve on the design of the prosthetics he'd been using since he lost part of his right arm in an ambush. Kuniholm and his colleagues founded the Open Prosthetics Project, an open-source collaboration that shares its innovations freely.
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An Open-Source Approach To Better Prosthetics

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An Open-Source Approach To Better Prosthetics

An Open-Source Approach To Better Prosthetics

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This is FRESH AIR. Im Dave Davies, senior writer for the Philadelphia Daily News, filling in for Terry Gross.

Jonathan Kuniholm was a graduate student in biomedical engineering at Duke before his Marine Reserve unit was deployed to Iraq. In January 2005, he lost his right arm below the elbow in a blast from an improvised explosive device.

He now works in the Revolutionizing Prosthetics Project, an effort funded by the Defense Advanced Research Projects Agency, or DARPA. The government has stepped up their research because of the number of vets returning from Iraq and Afghanistan needing limbs. The researchers are working with advance technologies to create a prosthesis that works almost as well as a real arm and hand. But most of their research hasnt yet made it out of the lab.

When Kuniholm came back from Iraq, he was given a myoelectric arm and a more traditional device. He chose to use the older model that uses metal pinchers operated by cables attached to his shoulder rather than the newer myoelectric arm with joints powered by electric motors.

Mr. JONATHAN KUNIHOLM (Co-Founder, Open Prosthetics Project): These prosthesis, these advancements are used by, you know, maybe less than 5 percent of the overall patient population missing arms. Only about half of arm amputees even wear a prosthesis at all. And of the ones who do, most end up wearing these body-powered prosthesis.

And so the effort in the rehab community was to try to get greater use of these advanced ones, and see, you know, that its not clear whether the reason that people dont wear them is because of how well they work or how much they cost. Insurance often doesnt reimburse for them. Its viewed by the insurance industry as a cosmetic device and not a functional one. And I wasnt satisfied with those myoelectric devices. I find them to be heavy, slow, a hassle to keep recharged. The way that they attached to your body is uncomfortable and restricts your range of motion. And as you say, I ended up wearing, you know, with some advancements in materials, essentially what people got returning from World War II.

DAVIES: So lets talk about the differences here a little bit. I mean, the prosthetic that people have been wearing for years and years, people would recognize that it has essentially a hook on the end, right?

Mr. KUNIHOLM: Thats right. David Dorrance patented this device first in 1912. And if you look at that 1912 patent, I got some pictures on our Web site, you would recognize it as the ancestor very much of the device that I wear today, although minus titanium. And it has some very interesting features. I mean, its been criticized by others in the media as being nothing more than a rubber band on a stick. And, you know, and the fact is that there is a lot of thought and evolution in designs that has gone into that. You know, I will say that it remains an inadequate solution to replace a hand. But my belief, which is not shared by everyone, that its the most functional device available.

So what it is is a couple of curved pieces of metal that we call fingers and then another piece of metal sticking out at an angle that we call a thumb that has a cable on it. And by either extending your forearm or by shrugging your opposite shoulder to which this cable is attached, you can pull the hook open and the rubber bands pull it shut. So, in this way, you could hold a cup with it.

And one of the interesting features that might not be immediately obvious looking at it is the fingers have a little bit of a curve to them. So, for example, the curve finger would reach around the back of a cup and keep it from slipping out when its enclosing a cup. And theres a little feature in the rubber, in the fingers thats been there since just after World War II that they then called a cigarette notch and is, I think, now a pen notch.

You would think one of the funny things about this is you would think, looking at old films, Best Years of Our Lives where an amputee from World War II won an Academy Award, an amateur, not an actor. And there are, I think, maybe three times in the movie hes shown lighting a cigarette with book of paper matches with his pair of hooks. Hes a bilateral amputee, missing both arms. And this and many other things might give you the impression that returning veterans to smoking was one of the major rehab goals

(Soundbite of laughter)

Mr. KUNIHOLM: after World War II.

DAVIES: Right. One of the challenges here is that, when you think about it, we move our arms and hands and wrists, and one trick is to get all of the different movements that would approximate what we do now. But we dont just move our things, we actually apply force. We lift objects. We twist doorknobs and jars. And if youre going to make an arm that actually does that, it has not just - you need not just to make it move. You need to give it power. So I wanted to talk about some of the technical challenges in creating a more realistic arm. Where does the power come from? Electric motors?

Mr. KUNIHOLM: The project that Im involved in - and, in fact, both DARPA projects ended up focusing on electric motor-powered prosthesis. But along the way, the four-year program consider a whole bunch of other ones, including a peroxide-based one from Vanderbilt that theyd called the rocket arm. Their hydraulic arms were considered.

One of the two tracks in the four-year program involved a device called a cobot(ph) that was developed by a company called Kinnya(ph) in Chicago. It was a really incredible device, a central spinning shaft with 15 balls being rotated by the shaft and steering motors on each one. So you get the single motor able to apply continuously variable force on 15 different tendons pulling in the hand - I mean, truly incredible things. But really, the best thing that we have going in terms of compact application of power in robotics is the electric motor. And so thats where everybody ended up focusing.

DAVIES: So, yeah

Mr. KUNIHOLM: Let me first say really quickly that I think your question sort of indicates a bias both in the rehab industry and the general populace. You mentioned the effort to create a realistic arm. And this is a bias I think of the two-handed in a lot of ways, because if you ask most amputees, what they really want is to restore functionality and not how realistic the hand might look. And there are a lot of sacrifices that end up being made in trying to make something look like a hand. And so, you know, a lot of times people look at these hooks and their first reaction is, gosh, I wouldnt want to walk around with that thing attached to me. You know, it ought to look like a hand. But the reason a lot of us have voted with our feet for these hooks is because theyre the best thing to restore function right now.

DAVIES: In developing a more advanced prosthesis, in addition to having an arm which has these batteries and electric motors so that it can make the prosthesis perform a lot of functions and exert force, you have to figure out how the wearer communicates its wishes and commands to all that machinery. How do you do that?

Mr. KUNIHOLM: There really are several challenges associated with this. The overall goal of the four-year project is direct neural integration and thought-controlled prosthetic hand control. I personally, while that interests me as a user, Im much more focused on what I might actually be able to have now. And there is

DAVIES: Just to clarify, Jonathan, when you said neural control, are you talking about having the prosthesis, in effect, wired into your brain?

Mr. KUNIHOLM: Yes. Thats exactly right. And obviously that when you think about the ideal, thats what we would all like. But at the same time, as a user, you know, that's a clinical study that I'm not interested in signing up for. I dont need anything plugged into my brain right now.

And the other part of this is that we have available to us, some technology that's been around for more than 20 years that is actually quite effective at determining user intent for a large number of patients and nothing has been done with that technology. That technology is myoelectric pattern recognition.

So these little censors, when you put them on the surface of the skin, can detect the little electrical impulses that are made by your muscles under the skin. And all of the output of those censors together, is then compared to intended movements, and you train it much like you would voice recognition software. So you go through a series of movements just like a voice user might read the Gettysburg Address and then you know which words the user was trying to say.

DAVIES: Jonathan Kuniholm works on the Revolutionizing Prosthetics Project.

Well talk more after a break.

This is FRESH AIR.

(Soundbite of music)

DAVIES: Our guest is Jonathan Kuniholm. He's a biomedical engineer who lost part of his arm in action in Iraq. He now works on a Defense Department-funded project to develop better prosthetics.

Well, Jonathan Kuniholm, youre working in a Defense Department-funded effort at the Applied Physics Laboratory at Johns Hopkins. It's called the Revolutionizing Prosthetics Project and you work with a team of engineers. I assume that you are different from them and youre the only one who actually is missing part of a limb. When theyve developed a, you know, a prototype prosthesis, do they have you strap it on and try it?

Mr. KUNIHOM: Weve done some of that, although I have not been able to take anything home that weve been working on the project. It's all been things that I used in the lab environment for relatively brief periods of time. I mean one of the things that a lot of people probably dont realize about R and D programs is that prototypes very often require a team of engineers hovering around something, just keeping it working.

And so there will be, you know, a demonstration or a photo opportunity or something like that, and the impression could be given that much more has already been accomplished than actually has. You know, one of my impressions about all this, having been involved in a bunch of media coverage of all these various things, is that we absolutely have an incredible bias in the media. And that bias is not a political one, like most of my friends on either end of the political spectrum might say that it is.

Its, in fact, a bias towards entertainment - and that entertainment can be a really good story or a really bad story and anything that's more complicated in between, usually is just hard for people to understand and people in the media aren't interested in covering that.

DAVIES: So what they want is a miraculous arm that works or a story that this is all a waste of money?

Mr. KUNIHOM: Exactly. Or that, you know, or that it's just a travesty, you know. And then on the other end of the spectrum, a lot of stories that I've involved in about amputees have sought to talk about this incredible technical achievements that we're making. And what I think a lot of those stories ignore, is the challenges that remain in getting the stuff to market and you know, even tested out on significant numbers of patients.

The reimbursement structure, for example, remains a huge challenge. You know, an example is a, you know, a year or two ago I got a call from a kid who's 17 years old, blew his hand off with a homemade firecracker. He has, and this is typical in a lot of the insurance industry, a $1500 lifetime cap on prosthetic services.

That's not going to buy him even a third of the arm that I'm wearing that weve just talked about as being a really low tech, essentially World War II technology. And I get emails, nearly daily, from people who can't get a prosthesis at all. And so the really advanced ones that I was talking about, which I have just said I felt were, sort of, even themselves, inadequate and not a great solution, costs - for somebody of my level of amputation - $35,000.

And the really highly articulated ones from these research projects that we're talking about will likely cost hundreds of thousands of dollars for a single copy. You know? So there's going to need to be insurance reimbursement of this or it will not succeed. I mean we will have made something that nobody can afford to buy.

DAVIES: Because there has to be a market if anybody's going to manufacture it, right?

Mr. KUNIHOM: Yeah, I mean...

DAVIES: Right.

Mr. KUNIHOM: know, the Defense Department and the VA have come out very strongly to support those of us who've lost arms in conflict in any way that they can. And I have absolute confidence that those agencies would absolutely buy these things for us as soon as they're available. I mean that's the reason that these entities are doing research to try to create the things that they wish that they could buy for us now that they can't

What a lot of people dont realize though, despite the amount of attention that weve gotten in the media is that as of February, only a 186 of us had lost parts of arms in both of these conflicts combined since 2003. And, you know, that makes us only a very small fraction of the, you know, on the order of 70,000 people in the United States who are missing arms.

DAVIES: You know, youve written how some of the companies that are involved in making prosthetic devices have used proprietary and encrypted stuff to, you know, not share what they're doing because they, I guess they want to make money from it.

And I'm just wondering if these companies are going to be benefiting from this government funded research, is there a way to make them share their technical information so that others can, you know, develop devices which work with them and attach to them?

Mr. KUNIHOM: I would really love for that to be the case, because, you know, the government has been the only game in town in R and D in this area for some time. I mean all of the advances that we talked about following World War II were, in fact, government funded. And for a period of time following World War II, all of the prosthetic patents associated with this research were assigned to the secretary of the Army.

I mean I personally believe that we ought to do something similar. Although, at the same time, there are legitimate arguments for trying to get stuff, that last mile through some commercial incentive. And so the argument has been made on the other side, that unless somebody has some sort of competitive advantage that they can exploit, they won't follow this through and take things to production.

Although, I think an argument to counter that is that, in a lot of areas, there has not been even a dime of private money spent on a lot of the stuff, even to take it through clinical trials. And, you know, that being the case, it sort of makes you wonder why do we really need to give somebody a monopoly for some extended period of time, you know, if we could just turn around and make it sustainable simply to make these things.

But what I do know is that weve done a, you know, hundred year experiment in doing things the traditional way that's been an utter failure and so, you know, I have some ideas that some might think are fairly radical but, you know, it may be time for some radical thinking.

DAVIES: Jonathan Kuniholm...

Mr. KUNIHOM: Yeah.

DAVIES: ...thanks so much for speaking with us.

Mr. KUNIHOM: Thank you very much for having me. I appreciate it.

DAVIES: Jonathan Kuniholm is a biomedical engineer who was wounded in Iraq and now works on the Revolutionizing Prosthetics Project funded by the Defense Advanced Research Projects Agency. His work is featured in a book by Michael Belfiore about DARPA's research called "The Department of Mad Scientists: How DARPA Is Remaking Our World, from the Internet to Artificial Limbs." You can read an excerpt on our Web site, FRESH

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