Powered prosthetic legs have the potential to replace a good deal of the functionality that original limbs used to perform in disabled patients. Yet, they’ve been pretty dumb as far as recognizing the type of movement necessary to perform in different situations. Walking up and down stairs is very different from walking up and down a hallway, so most powered lower limb prostheses required the user to tell the device what gait to take on using some sort of controller. Researchers at the Rehabilitation Institute of Chicago have now developed a control system for leg prostheses that understands the intentions of the wearer and automatically adjusts its motions to fit with where and how the person is walking.
The system relies on electromyography (EMG) sensors positioned over the muscles of the remaining leg. The signals gathered by the sensors are fed into a computer that aggregates them and deduces the wearer’s intentions. Since the signals come from the very muscles that used to move the original appendage, the activation of the prosthesis is completely natural and intuitive for the user. Moreover, the system uses pattern recognition algorithms to predict the next stride and adjusts accordingly to produce the kind of step the wearer intends.
Here’s a video produced by the Journal of the American Medical Association that shows off the new prosthesis control system: