Control and Experimental Results for Post Stroke Gait Rehabilitation With a Prototype Mobile Medical Exoskeleton

Repetitive task-oriented exercises are accepted in traditional gait rehabilitation and have given rise to driven gait orthoses, but both methods suffer from limited rehabilitation time for the patient. The presented device proposes a control strategy and implementation unique for a mobile rehabilitation exoskeleton as well as results from initial subject testing. This anthropomorphically designed device has knee and hip joints that are actuated in the sagittal plane using hydraulic actuators. The presented control strategy allows the user or therapist to directly specify the level of rehabilitation assistance desired between complete machine control and a zero impedance joint. The device was experimentally tested on three chronic stroke patients with noticeable gait improvements based on the metric of joint flexion. Other results of step time and step length are presented that do not demonstrate as clear improvements but these are believed to be a function of the limited patient testing time.