Kinematic Analysis of the Bio-inspired Design of a Wearable Compliant Gait Rehabilitation Robotic System for Smart and Connected Health

Abstract

The design of a novel actuator VIC-SEATS (Variable Impedance Compliant Series Elastic Actuator with Two Springs) is introduced and the static and kinematic characteristics of the soft actuator for a targeted application of actuating the knee joint of a gait rehabilitation robot is presented. Targeted novelties of the actuator design are that it is designed with only one motor and two sets of springs in series that can adjust the stiffness for low, medium and high force situations without any change in the springs, it is light in weight, compact in size but enough strong due to proposed fabrication with advanced materials, and it has competitive advantages such as high force controllability, force bandwidths, back-drivability, efficiency, safety, power/mass and force/mass ratios and output torque, and low friction, inertia and impedance. The electro-mechanical design, prospective fabrication materials and working mechanisms of the novel actuator design are summarized. Based on simulation results, the design parameters are optimized to determine desired static and kinematic features such as torque trajectory, torque-displacement relationship, velocity profile and required power/energy for actuating the knee joint of a gait rehabilitation robot through comparing these characteristics with the human characteristics. Then, applications of hand-held gaming interface to display key rehabilitation performance and the tele-rehabilitation facility for connected health are analyzed. Finally, social and technical motivations for stroke patients towards utilizing robotic rehabilitation devices are analyzed.