Detailed cost figures were not available, but researchers at Johns Hopkins Applied Physics Laboratory, working with specialists around the world, have developed a prototype bionic limb that moves at eight different joints and gives heat and pressure signals to the wearer.
In the first part of a four-year federal program, Proto 1 uses patient Jesse Sullivan?s original motor control nerves, rerouted to a grid in his chest, said project leader Stuart Harshbarger, of APL in Laurel.
Discovering the sensory feedback was a lucky surprise, he said
“It wasn?t planned; we sort of lucked into it,” Harshbarger said. “There?s a map on his chest. If you push on that map, he feels different areas as if you?re pushing on his hand. He also feels temperature differences.”
Doctors removed sensory nerves from the Michigan lineman?s chest, replacing them with the motor-nerve bundle from his arm. What they found was that the sensory nerves came with the package. Engineers working on the arm modified it to make use of those nerves, as well.
Another major milestone for this prosthetic is that it fits entirely within the natural form of Sullivan?s original arm. A latex rubber coating expertly painted to match earlier photos of Sullivan makes it look like he never lost his arm in an electrocution accident.
Proto 1, developed for the Defense Advanced Research Projects Agency?s Revolutionizing Prosthetics Program, allows unprecedented freedom, including multiple thumb grips, a swinging motion to allow Sullivan a more natural gait.
Eventually intended for injured soldiers, the project is entering its second of four years. By this summer, Harshbarger said, they expect to unveil a second prototype with 25 to 27 degrees of freedom and individually controlled joints and pivots.
Proto 1 was fitted for clinical evaluations conducted by team partners at the Rehabilitation Institute of Chicago in January and February. Harshbarger leads a group of more than 30 government agencies, universities, and private firms from the United States, Europe and Canada.
“The results we are achieving in this highly collaborative project are very exciting, and I am confident that these discoveries will bring more natural control of prostheses, better artificial limbs and make a difference in the lives of amputees worldwide,” said Dr. Todd Kuiken, the director of the Neural Engineering Center for Bionic Medicine at RIC.
