University Team Moving Forward With Bionic Limb Research

A team led by Assistant Professor Dustin Crouch seeks to unlock what would be a game-changing jump in prosthetic devices by using technology that has so far largely only existed as fantasy: bionics.

The key component of the research is what are called muscle-driven endoprostheses (MDEs), which are a type of prosthetic that is completely implanted under skin in a patient’s body.

“We want to physically attach prosthetic limbs and appendages to the muscles that remain in the residual limb after amputation,” said Crouch, who works out of the Department of Mechanical, Aerospace, and Biomedical Engineering. “Using the residual muscles and tissue will enable patients to do things that current technology doesn’t allow for.”

By using the muscles that remain after amputation, the thought is that it would be possible to create prosthetics that approached 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.”

Having the new devices connected to existing muscle means that people would have a more “natural” experience of their new appendage being with them and functionable at all times, instead of having to remove and reattach them as the situation dictated.

Like most scientific undertakings, the group has started at the small-scale side of things, beginning with prosthetic feet for rabbits. Using synthetic tendons to attach muscles to a small prosthetic foot and ankle in the leg, the team will be able to get feedback from the foot, such as strength and reflexivity, that will help them design later models.

Eventually, the goal is to work up to human-based implementation, where, once again, the team will start small before building up to full-size limbs, likely beginning with individual fingers or toes. Crouch said he hopes the work has advanced to that level well within the next five years.

“The whole goal of this is to improve outcomes for people who have undergone amputation,” Crouch said. “People have to change jobs, maybe even quit work altogether because of limb loss. This could drastically change lives for the better.”

As a sign of the importance of the work, the National Science Foundation selected Crouch for one of its prestigious CAREER awards, which go to up-and-coming faculty with ideas it deems important to humanity.

Source: University of Tennessee