Researchers at Michigan Technological University, in partnership with the Mayo Clinic, are working on a microprocessor-controlled ankle-foot prosthesis they say comes close to achieving the range of motion of an ankle.
As part of their study, the researchers built a large circular treadmill on which the prosthetic foot walks in circles. In tests, the researchers found that the prosthesis was able to copy the angles of a human ankle walking in a straight line and turning. In contrast, current microprocessor-controlled prostheses can move a prosthetic foot in one direction, toe up and toe down.
“We never walk in a straight line for any length of time,” Mo Rastgaar, PhD, assistant professor of mechanical engineering-engineering mechanics at Michigan Technological University, said in a press release. “When you walk and reach an obstacle, you have to turn, and there’s always something in our way.”
The prosthesis has pressure-sensitive sensors on the bottom of the foot that detect how the amputee is walking and sends signals to a microprocessor, which adjusts the prosthesis to provide a more natural gait.
The researchers will present a paper on their work at the ASME Dynamic Systems and Control Conference at Stanford University Oct. 21-23.