Evaluation of a prosthetic swing-phase controller with electrical power generation.

With the increased presence of microprocessor-based prostheses in the market place, the availability of a self-energizing system has practical applicability. At present, most commercially available systems require the user to routinely recharge on-board batteries, which reduces the utility of these prostheses. To address this limitation, we have proposed a unique system based on an electromechanical generator to not only continually recharge batteries that are on-board the prostheses, but to also serve as a real time swing-phase damper. A prototype system was developed and evaluated with three active individuals with above-knee amputations across four damping conditions and two gait speeds. Gait and power generation performance were assessed via selected temporal, kinematic and kinetic parameters. Gait parameters including cadence and knee angle symmetry were found to be acceptable when knee damping was adapted for each participant. Across the three subjects and two walking speeds, between 0.57 and 1.57 W of electrical power was produced. These results indicate that this technology may be utilized for prosthetic swing-phase control and ultimately may alleviate the need for manually charging of microprocessor-based prostheses.