A Hybrid Neuromechanical Ambulatory Assist System

A hybrid neuromechanical ambulatory assist system is being developed for walking after lower extremity paralysis that combines the stability and constraints of a novel hydraulic exoskeletal system with the mobility powered by the individuals own paralyzed muscles contracting via functional electrical stimulation. A mobile computing platform is designed to provide real-time closed-loop control using brace mounted sensors to deliver the stimulation needed to stand up and walk while coordinating exoskeletal control mechanisms at the hips and knees to maintain stability. A variable constraint hip mechanism couples hips as needed to maintain posture and reduces the need for upper extremities to maintain balance. The knee locking mechanism is designed to allow the stimulated muscles to rest during stance while permitting unconstrained movement during swing. A knee flexion assist is being explored to provide sufficient foot clearance during swing on an uneven terrain. The exoskeleton is designed for easy fitting with adjustable uprights and hip abduction for donning for use in activities of daily living for persons with paraplegia.