Design and Biomechanical Evaluation of a Soft Lower Limb Exoskeleton for Elderly Assistance

Abstract

Age-related Motor Dysfunction will inevitably cause a reduction in physical movement capacity and life quality among the elderly, and raise the risk of falls. Lower robotic exoskeletons can offer assistance to the wearer, while most of them are rigid, bulky, and not suitable for daily use. Employing a pneumatic actuating mechanism, a novel soft lower limb robotic exoskeleton was developed in this paper. The pneumatic actuators were designed as airbags and assembled in a queue to form the main body of the soft exoskeleton. To correctly and timely control the exoskeleton to assist the user, a pair of plantar pressure sensors was embedded in the shoes to detect the moment of leg lifting and recognize the gait. The assistive and biomechanical performances of the exoskeleton were evaluated with healthy human subjects. Qualitative assessment of the developed exoskeleton was also conducted. Experimental results show that the developed soft exoskeleton can achieve an assistive efficiency of 5% ~10 % in different conditions, which is quite acceptable for assisting the daily activities of elderly people. © 2018 IEEE.