Sasser tests the prosthetic ankle.
Photograph courtesy of Vanderbilt University.
The Vanderbilt University lab of Michael Goldfarb, PhD, has completed testing of a smart prosthetic ankle that can respond to varying terrain and stairs. The ankle’s motor, actuator, sensors, and chip work together to either conform to the surface the foot is contacting or remain stationary, depending on the user’s needs. The team hopes to commercialize the ankle within about two years.
“Our prosthetic ankle is intelligent, so you can wear a dress shoe, a running shoe, a flat—whatever you’d like—and the ankle adapts,” said Goldfarb, the H. Fort Flowers Professor of Mechanical Engineering; professor of electrical engineering and physical medicine and rehabilitation; and co-director of the Center for Rehabilitation Engineering and Assistive Technology at Vanderbilt. “You can walk up slopes, down slopes, up stairs and down stairs, and the device figures out what you’re doing and functions the way it should.”
Most prosthetic ankles lack smooth roll over when walking, causing the user to swing the prosthesis outward.
“I’ve tried hydraulic ankles that had no sort of microprocessors, and they’ve been clunky, heavy, and unforgiving for an active person,” said Mike Sasser, who has a transtibial amputation and tested the device over several years at Goldfarb’s engineering laboratory. “This isn’t that. It actually lifts the toe for you.
Harrison Bartlett, a doctoral student in Goldfarb’s lab, gathered feedback from the sensors and made adjustments based on the data and Sasser’s user experience. Bartlett also interviewed nearly 100 potential users to understand what would make the ankle a success.
“I talked to one person whose favorite restaurant was at the top of a long flight of stairs, so they haven’t eaten there in ten years,” he said. “Another sat on benches throughout an amusement park while their family enjoyed the rides because they couldn’t be sure about navigating that with their prosthetic. We want to return people to any of the life activities they want to do.”
This story was adapted from materials provided by Vanderbilt University.