Oh yeah...the OPP is the place to be for innovation and creation to make your artificial limb a sensation.

We all have those moments when we look at a commercial gadget and think: “you know what this thing really needs is a…” Now imagine that gadget is an artificial limb that you will attach to your body for hours a day, everyday, for the rest of your life. You’d probably have thousands of those moments. The Open Prosthetics Project is a forum where people with artificial limbs, or those interested in working with them, can discuss and share innovations for their devices. Want to make a prototype limb out of Lego? Need a quick way to model a residual limb? OPP is the place to find the community and expertise to help you. They even have a “Pimp My Arm Forum” to satisfy your tinkering day dreams. Check out some of OPP’s cool pics, videos, and links below.

Open source development has the potential to be very fruitful, with big name successes like Linux providing inspiration. We’ve also seen emerging trends in robotics lead by Willow Garage and their work with amazing research robots and operating software (ROS). Similar developments in synthetic biology are led by MIT’s Registry of Standard Biological Parts, iGEM, and the OpenWetWare wiki. The Open Prosthetics Project isn’t quite up to these standards yet. They’re very spread out – you have to track them across Google Groups, Ning, and Instructables to really get a handle on everything going on with the community – and there’s less than 300 members. Still, the range and creativity of their projects speaks volumes to the potential OPP has to lead a revolution in prosthetics from the user-base up.

Materials like Lego work as a means for prototyping some of the ideas at the OPP.

OPP is the brainchild of Jonathan Kuniholm, an Iraq War veteran and engineer at DARPA’s Revolutionizing Prosthetics program. We mentioned his work during a discussion on Deka’s Luke Arm, and Kuniholm was kind enough to comment on the story. Kuniholm’s work at DARPA features myoelectrics (muscle sensing technology) and advanced pattern recognition, but the projects highlighted on OPP run the gamut from very simple to extremely complex.

One of my favorite OPP programs is the Lego Hand. Developers are trying to find ways to build a prototype arm and hand from standard Lego components. I’ve seen some cool Lego constructions before, but this idea could really make a big impact in people’s lives. In the following video John Bergmann demonstrates a fully articulated Lego Hand he’s been working on. Eventually the group wants to have a powered upper body limb with myoelectric sensors.

As you’d expect from any social network, OPP doesn’t just serve to develop original content, it also highlights useful innovations from outside the community. On OPP’s Instructables channel you can find this short video of a way to form a mold of a residual limb in just 30 seconds. Wow! The original concept comes from work at Northwestern University.

Explore OPP and you may be surprised by what and even who you find. Bre Pettis, one of the founders of open source 3D Printing company MakerBot, has solicited input from OPP to see if 3D Printing might help with prosthetics and prototyping. I really hope something happens there. I would love to see amputees be able to print out prototype prosthetics for testing at just a fraction of traditional costs.

OPP is still in its early stages of development. This isn’t a hardened cadre of engineers, or a professional company with open source ideals, it’s a forum with a common goal. We shouldn’t expect another Smart Hand or Luke Arm to suddenly spring out of OPP overnight. What we may see is a place where the people who have to live with artificial limbs day in and day out get a chance to direct their own innovation. That may lead to some inexpensive, creative, and infinitely practical solutions to the challenges amputees face with their devices. Prosthetics companies should look to OPP not as a competitor, but as a resource that could highlight where the future of artificial limbs may need to be headed. Eventually, though, OPP could develop into something more. If enough experts join the community, or enough people in the community gain expertise, OPP could arise as a competitor, even as an industry leader. No matter what the outcome I’m fascinated by the craftiness and ingenuity of the OPP. Go and check it out for yourself.

OPP member Sean McHugh demonstrates one of the many uses of a standard arm hook. Hey, even innovators need to unwind.

[image credits: OPP, Sean McHugh]
[video credit: John Bergmann, Instructables]
[source: OPP]

Deka's Luke Arm is in clinical trials. Will it find favor with amputees?

The future of prosthetics isn’t certain, and we’ve seen so many different next generation devices, it’s hard to know which will ultimately arise as the standard. For legs, there are spring like mechanical struts that can outperform their biological counterparts, and there are complex electronic knees and feet that contain narrow artificial intelligence. Prosthetic hands, however, haven’t evolved much in the past 60 years. But that’s about to change. We’ve seen many different robotic hands in development, and one of the most popular in the press has been Deka’s Luke Arm. Dean Kamen, inventor of the Segway scooter and head of Deka, helped design the electronic arm to fit the needs and desires of modern amputees. The Luke Arm went into clinical trials this summer and could become the prosthetic limb of choice for US soldiers returning from Iraq and Afghanistan. Yet, despite the Luke Arm’s media presence (check out the 60 Minutes segment video after the break), I’m not certain it’s going to beat the competition.

For those who missed our first story on Deka’s Luke Arm, I should explain that it is controlled by pads under the feet and attached to shoulders muscles. Like a complex video game, users press on these pads to get the limb to perform desired actions. This is a robust system that allows for a precise level of control. It also takes a while to get used to. Competing prostheses, like i-Limb, use myoelectric sensors that can read nerve signals in muscles. Essentially, you think about moving your missing hand, and the prosthetic performs the action. The two approaches, joystick versus mind-control, seem grossly mismatched in the favor of the myoelectric sensors. How is the Deka arm staying competitive?

Well, largely I think the Luke Arm is winning because it is already able to start clinical trials, has Dean Kamen attached to the project, and is a remarkable piece of machinery. No doubt, the Luke Arm performs very well. It’s customizable, modular, and robust. At only 8 lbs (3.6 kg), it contains electric motors that give it 18 degrees of freedom (the human arm has 22) and pressure control. A vibrating device, called a tactor, gives the user feedback sensation that allows him or her to stop the Luke Arm before it crushes an object. In the video you can see how the device is gentle and sensitive enough to pick up a grape.

As mentioned, the Luke Arm is part of DARPA’s Revolutionizing Prosthetics program. Deka received close to $18 million for the development of its device, but $30.4 million went to John Hopkins Applied Physics Lab for an alternate prosthetic that uses myoelectric sensors. That device, and APL researcher Jonathan Kuniholm, is shown towards the end of the 60 Minutes segment.

DARPA is hedging it’s bets, spreading money around to see which projects will bear fruit. Smart idea. The Luke Arm’s current trial utilizes the control pads we discussed earlier, but Kamen isn’t ruling out the use of myoelectric sensors in the future. Between the APL and Deka, DARPA is bound to get at least one fieldable prosthetic very soon.

But if you’re not a veteran, neither DARPA project may really help you much. The Luke Arm is slated to cost $100,000+, and a similar price is likely for the APL limb. That’s well beyond the means of most amputees if they do not have the insurance coverage provided by the Veteran’s Administration. The i-Limb is offered at a cheaper price (near $18,000) and is already being tested by 600 users. As most amputees are not veterans, I think that the Luke Arm has a good chance of being priced out of a large market share.

Which is why I was very interested in Jonathan Kuniholm’s Open Prosthetics project. The same biomedical engineer working at APL (on the DARPA grant) is an advocate of open source solutions and hopes that a cheap and reliable alternative could be provided for those without the means to spend hundreds of thousands of dollars. Kuniholm gave an amazingly frank and thought-provoking interview to NPR’s Fresh Air earlier in the month. He discussed the budget limitations of amputees, the bias non-amputees have on appearance over function, and the media’s preference for hyperbolic stories (around 11:02). Give it a listen:

After hearing Kuniholm criticize the media for telling just two versions of technology stories (“this device is amazing, it’s going to change everything” or “this device is a horrible waste of money”) I am inclined to give a very measured outlook on the future of prosthetics. The Luke Arm is a great piece of machinery, and it’s likely to be ready soon, but it could be too costly to own and too difficult to operate. Myoelectric devices could offer some amazing possibilities, but they aren’t here yet. Surgically augmented devices, like the Smart Hand, could offer realistic feedback via nerve connections and completely outperform any other limb. But those devices are years from completion. The bottom line is that the first commercially available next-generation upper body prosthetic could be the Luke Arm, but it is certainly not going to be the last. Whichever device eventually sets the standard for limb replacement will have to be adaptable, affordable, and above all functional. May the best hand win.

[photo credit: IEEE Spectrum]
[video credit: 60 minutes via CNET]
[audio credit: NPR Fresh Air]