BME Jackson Family Distinguished Professor Helen (He) Huang’s Neuromuscular Rehabilitation Engineering Lab (NREL) has been working on an ankle prosthetic that relies on the user’s residual muscles to help amputees with their postural control. With funding from the National Institute of Biomedical Imaging and Bioengineering (NIBIB), Dr Huang and her team recently reported their first case study evaluating this prosthetic device operated solely by the body’s own electrical signals, a concept known as direct electromyographic (dEMG) control.
“Oftentimes, if part of our limb is removed, we start to use the muscles in the residual limb a little bit differently,” explained Huang. This can result in altered muscle contraction patterns, and when a dEMG prosthetic device is used, the intended limb motion and the actual limb motion will be out of sync, she said. For this reason, the prosthetic user, with the aid of a physical therapist, will “train their muscles—and their brain—to better control the prosthetic ankle,” explained Aaron Fleming, a graduate student in the Huang lab and first author of this case study.
After the training, the participant’s stability was markedly improved when wearing the dEMG-controlled device, even when standing on a foam surface or with his eyes closed (which also tests balance). The researchers also found that the synchronization between the intact and artificial limbs was far higher when wearing the dEMG-controlled prosthetic. Dr Huang and her team’s next goal is to conduct systematic clinical evaluation of their technology. Congratulations to Huang, her team and collaborators! To read the full feature, visit NIHBIB website here. For the full publication of the case study, visit Cambridge University Press here.