Rastgaar’s team has also refined the actuator’s design, making it lighter and more streamlined. Because the foot is moved by lines similar to bicycle brake cables, the actuator does not have to be mounted on the prosthesis, where the user must to move it with every step. Instead, it could be carried in a pocket or fanny pack, for example.
“Also, this new actuator system will be easy to remove, so you can use it or not, based on your needs,” Rastgaar says. “If the user is going to stay at home, it might be simpler to walk around the house with a passive prosthesis.”
Rastgaar hopes the robotic ankle will eventually find its way out of the lab and onto the sidewalk. “One of these days, we hope this can be brought to market, where it could really help people.”
The research is being partially supported by a five-year Faculty Early Career Development (CAREER) Award from the National Science Foundation (NSF), and a provisional patent has been issued for the technology. In addition to Rastgaar, researchers involved in advancing the project include Nina Mahmoudian, an assistant professor of mechanical engineering-engineering mechanics at Michigan Tech; PhD candidate Evandro Ficanha; PhD student Guilherme Ribeiro; Kenton R. Kaufman, professor and director of the Biomechanics/Motion Analysis Laboratory at the Mayo Clinic; and Neville Hogan, professor and director of Newman Laboratory for Biomechanics and Human Rehabilitation at MIT.