An inspiring segment on last night's episode of 60 Minutes profiled the work of DARPA's (Defense Advanced Research Projects Agency) "Revolutionizing Prosthetics" program, a $100 million project intent on advancing a field that, in some respects, hasn't changed much in more than 50 years.
The piece concentrated on the DARPA-funded DEKA arm, developed by inventor Dean Kamen and his team of 40 engineers. Size and comfort were key issues in designing the limb. The final product is the size of an average person's arm, weighs around nine pounds, and is buffered from the wearer's body by small balloons that expand and deflate as pressure on the arm changes (the balloons inflate when the wearer picks up something heavy, and deflate when the arm is at rest). Controlling the arm using their shoulders and pedals in a specially designed shoe, volunteers demonstrated their ability to pick up and drink from a soda bottle and eat a grape.
The end of the segment touched on the future of prosthetic control, featuring Duke University engineer Jonathan Kuniholm. Kuniholm, who lost his forearm in Irag, demonstrated his ability to control a prosthetic hand using the nerves still intact in the remaining part of his arm. These nerves send out small electrical signals, which a processor in a prosthetic arm can be trained to interpret.
Similar work is being done here by Northwestern faculty member Todd Kuiken and his research team at the Rehabilitation Institute of Chicago. They are using an exciting new procedure called targeted reinnervation to reroute nerves that used to control a missing limb to different, intact muscle areas (rerouting nerves that used to control an amputee's arm to his or her chest muscles, for example). These reinnervated muscles can then communicate with a prosthesis, again allowing the wearer to control their limb intuitively. Click here to read an SiS article on the Kuiken team's work.