Design, Prototyping, and Testing of a Robotic Prosthetic Leg Preliminary Results

We report on our design and initial evaluation of a prototype robotic prosthetic leg (RPL) with a powered non-backdrivable knee and a hydro-pneumatic passive-resistive ankle. Our design was intended to increase health providers’ opportunities when offering their patients greater options, expanding the accessibility of advanced technology to those with lower functional levels of ambulation while decreasing the overall costs of care. The purpose of this biomedical device was to improve stance stability, increase balance confidence, and through powered-knee extension, reduce the contralateral limb’s kinetic stresses in gait, sitting, and standing. This device was designed to provide K2 and above ambulators a more adaptive, safe, and enhanced lower limb prosthesis. The prototype was assessed on a healthy subject while performing multiple 10-meter walk tests (10MWT) and six-minute walk tests (6MWT) on level-ground, inclines, and declines. We report walking velocity, the frequency of steps, cadence, falls, stumbles, toe-drags, battery consumption, and estimated torque of the knee actuator. We found the device safe on an able-bodied subject and feasible for future use on persons with limb loss.