Design validation of the MATE tendon-based passive device for post-stroke rehabilitation

Abstract

Rehabilitation robots have been shown to be effective in post-stroke gait rehabilitation. However, these devices are usually expensive and suffer from high inertia which decreases transparency. The Minimally Actuated Tendon-based exercise Environment (MATE) is a tendon-based rehabilitation device, designed to be cost-effective and minimize inertia effects. The MATE must apply minimal forces to the wearer if the gait cycle is healthy to prevent deviation into an unhealthy gait. Previously a mathematical optimization was performed on the design of the MATE. This thesis aims to make a physical realization of the MATE to investigate the minimal forces during a healthy gait cycle with two experiments. The first experiment attached the tendons to a machine to investigate forces on a non-altering gait. HTC VIVE motion trackers were used to measure the position of the tendon attachments over time. To measure the tension, in each cable inline tension sensors were added. Comparing the measured forces to velocity-based thresholds indicates that the forces applied by the MATE are too high and would cause deviation. The second experiment involved a human walking with and without the MATE. Evaluating the gait cycle trajectory when walking with and without the MATE indicates that the MATE alters a healthy gait cycle, lowering the step height and causing drift. The forces acting on this gait also exceed the thresholds. The MATE in its current design alters a healthy gait. Redesigning the MATE with the suggestions from this thesis will likely show further improvements.