A team of researchers at the University of Tennessee (UT) are studying muscle-driven endoprostheses (MDEs), a type of prosthetic device that is completely implanted under the patient’s skin.
“We want to physically attach prosthetic limbs and appendages to the muscles that remain in the residual limb after amputation,” said Dustin Crouch, PhD, an assistant professor who works out of the university’s Department of Mechanical, Aerospace, and Biomedical Engineering. “Using the residual muscles and tissue will enable patients to do things that they cannot with current prosthetics.”
By using the muscles that remain after amputation, it may be possible to create prostheses that approach the same mobility and dexterities as the original limb.
“Many amputees are able to remember how to control the muscles that used to be there, are able to ‘feel’ that control,” Crouch said. “Humans have a remarkable ability to modify how they coordinate their muscles. One aspect of implementing this will be getting amputees to relearn how to coordinate their muscles to directly control their new devices. We want it to feel as natural as possible.”
Another advantage of the new technology is that it would solve two complaints people often have about their artificial limbs: weight and convenience.
Crouch’s approach would eliminate much of the bulkiness associated with many prostheses since muscles don’t need batteries or motors to operate. Additionally, having the new devices connected to existing muscle means that users would have a more natural experience with the device, instead of having to remove and reattach them.
The research team, which includes member from UT’s College of Veterinary Medicine, began testing their method by using synthetic tendons to attach muscles to small prosthetic feet and ankles in rabbits’ legs. The team will be able to get feedback from each foot, such as strength and reflexivity, that will help them design later models.
Once the researchers work up to human-based implementation, they will likely begin with individual fingers and toes before building up to full-size limbs, they say. Crouch said he hopes the work has advanced to that level well within the next five years.
Editor’s note: This story was adapted from materials provided by the University of Tennessee.
