Open Arms

Otto Bock’s decision is not a unique development. Deka Research has declared that it has no intention of participating in any open standard for communication. However, the wrist rotator on Deka’s arm remains too large for below-elbow amputees like me to use. Addressing the specific needs of below-elbow amputees was not a DARPA requirement, but most arm amputations are below the elbow. The ability to swap different manufacturers’ components would have solved that problem.

It’s worth looking at this in terms of the current economic stimulus or recovery packages. We’re spending a lot of government money doing something that industry has failed to do, so we need to ensure that we’re getting our money’s worth. Col. Geoffrey Ling, the program manager on the Revolutionizing Prosthetics project, made it clear from the start that this wouldn’t be just another science project—this project would have real benefits in the real world.

So in the middle of the four-year project, the APL team decided to open up the framework of its project. The steps it is taking are virtually unheard of: First, APL is making its virtual environment open source. The APL team has created a virtual integration environment, a training simulation in which signal processing and control techniques can be tested and an amputee can watch him- or herself drive a virtual arm. Second, the team also plans to publish an open control communication architecture for the limb. Finally, APL intends to publish the mechanical interfaces for each physical component, such as the wrist rotator or the finger joints. (Opening the architecture for mechanical and electrical interfaces, by the way, should not be confused with open-source software; adhering to a common interface doesn’t require a manufacturer to publish trade secrets about how its improvements were made.)

These innovations will give any company—or individual—access to the physical specifications of the APL arm as well as parts of the control software. They’ll even have a virtual environment in which to test their adaptations.

The best way to really move prosthetics research forward is to hitch a ride on a real market. If we can find an application for a myoelectric human interface in the $32 billion worldwide video-game market, for example, we can tap into a massive reserve of people who might not otherwise get involved in the effort. Any tool they develop could be repurposed for prosthetics, allowing that small market to benefit from the economies of scale that are usually available only to much larger ones. The MyOpen project on the Open Prosthetics site is working on ways to create a product that can serve both a niche and a mass market. MyOpen, an open-hardware signal-processing board that will be compatible with APL’s arm, will also serve as a universal controller for video games. We want creative people to get their hands on this device and push it to the limits. We want this device to enhance the experience of playing video games, and in doing so, push prosthetics innovation into the 21st century.

Another possible application is robotics. Prosthetic arms aren’t the only devices that require centrally controlled powered joints. The compact and powerful motors designed for the APL project—less than a centimeter in diameter and capable of producing 8 watts—could be useful in bomb disposal, hazardous waste inspection, and home-service or hobby robotics, for example. If the communication standards developed for the DARPA project were adopted by one of these industries, then terminal devices like individual joints and hands could see much wider use. In turn, the devices would benefit from much more R&D.

Dean Kamen is famous for founding the FIRST (For Inspiration and Recognition of Science and Technology) mentoring program, which inspires young people to get involved in science and engineering. An open architecture for the Deka arm could be the basis for a FIRST competition with dexterous tasks—think DARPA Grand Challenge or a piano sight-reading competition. I’ve served as a mentor to FIRST Robotics Team 900 at the North Carolina School of Science and Math. Based on my experience with these students, I think they would relish the opportunity to work on a problem that significantly affects lives.

The greatest revolution of all may be apparent only after the frenzy of prosthetics research spending has evaporated. The design evolution for which DARPA is laying the groundwork could come from any quarter, inside or outside the prosthetics industry. And who knows—someone might even make money doing it.