Passive SPARKy-P Prostheses (Spring Ankle with Regenerative Kinetics)

SpringActive Inc. collaborating with Arizona State University will design and build a spring-based, passive prosthetic ankle that stores energy in the stance phase and returns it at push-off to propel the user forward. The team will leverage experience in designing tuned spring ankles. A plantarflexion spring will allow the ankle to plantarflex smoothly and align to the ground after heel strike. This same spring will bias the ankle-joint to a neutral position during the swing phase. A dorsiflexion spring will be tuned for energy storage and will be clutched-on as the tibia rolls over the ankle joint. The key technology will be to un-clutch the spring at toe-off to allow the foot to return to a neutral position. In Phase 1, the ankle will be tuned to allow for stable standing and normal walking speeds. The benefits of this ankle are: low-cost, light-weight, passive, no-batteries, no-microprocessor, energy storage and return, and an articulating ankle joint that allows the user to stand without the socket pressing against the tibia in the front of the lower leg.