Scientists Create Prosthesis Of The Future
Published: Oct 13, 2007Science Daily — Researchers at Arizona State University’s Polytechnic campus and the Military Amputee Research Program at Walter Reed Army Medical Center are teaming up to create the next generation of powered prosthetic devices based on lightweight energy storing springs.
The device, nicknamed SPARKy, short for Spring Ankle with Regenerative Kinetics, will be a first-of-its-kind smart, active and energy-storing transtibial (below-the-knee) prosthesis.
Existing technology in prosthetic devices is largely passive and requires the amputee to use 20 to 30 percent more energy to propel themselves forward when walking compared to an able-bodied person, according to Thomas Sugar, ASU assistant professor of engineering at the Polytechnic campus.
Once complete, SPARKy is expected to provide functionality with enhanced ankle motion and push-off power comparable to the gait of an able-bodied individual.
“A gait cycle describes the natural motion of walking starting with the heel strike of one foot and ending with the heel strike of the same foot,” says Sugar. “The cycle can be split into two phases — stance and swing. We are concerned with storing energy and releasing energy (regenerative kinetics) in the stance phase.”
When you look at the mechanics of walking, it can be described as catching a series of falls, explains Sugar. In the team’s device, a tuned spring brakes falls and stores energy as the leg rolls over the ankle during the stance phase, similar to the Achilles tendon.
