Development of a 4-DOF Mobile Manipulator for Repetitive Gait Training on the Track for Stroke Patients

Abstract

An overground track-walking scheme with a body-weight support system can provide task-oriented and repetitive training. Furthermore, it improves gait stability and endurance more effectively than the conventional treadmill walking method. However, it does not improve asymmetry and reduces gait speed. Accordingly, we developed a 4-DOF mobile manipulator in which the position of the handle is controlled to provide continuous somatosensory information (cutaneous & proprioception information), such as a fixed rail to the user's hand during overground walking for gait enhancement (velocity, symmetry, and balance). The system consists of 3 omni wheel-based mobile robot for robust track following and a 1-DOF revolute joint-based manipulator for gait enhancement during track-based gait guidance. To demonstrate the feasibility of the system, we conducted a pilot experiment with one stroke patient on a 15 m track. The experimental results showed that the robot could guide the patient along the track and enhance symmetry and balance, especially in the curved section of the track. Furthermore, the preferred walking speed of the participant on the track improved. Therefore, the system demonstrated promising potential for providing quantitative, repetitive, and safe track-based overground gait rehabilitation training.