Sparky prosthesis

Researchers at Arizona State University’s (ASU)'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 they are working on, nicknamed SPARKy – short for Spring Ankle with Regenerative Kinetics – will be the first-of-its-kind smart, active and energy-storing transtibial, or below-the-knee, prosthesis.

Existing technology in prosthetic devices is largely passive and requires amputees to use 20 percent 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,’ Sugar said. ‘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.’