Reducing Delay Time in Hand Mentor Pro to Improve Clinical Functionality

Abstract

Stroke is third leading cause of disability worldwide, and the burden of stroke across the world is steadily growing. However, it is the leading cause of disability in the United States. Each year, 800,000 people in the United States alone have strokes. This has necessitated the development of more effective methods of stroke rehabilitation. The Hand Mentor Pro is an assistive robotic device used stroke rehabilitation. Through the use of interactive goal-oriented games, it can deliver high intensity repetitive treatment. Currently, the Hand Mentor is actuated by a McKibben air muscle. This actuator has a significant lag of 1.85 milliseconds, presenting a serious obstacle to various clinical outcomes of the device. The aim of this study was to develop and test a novel actuation system that combines the Hand Mentor’s air muscle with a DC motor in order to reduce actuation delay time. Two experimental actuator treatments, DC motor and the combination of DC motor and air muscle showed to be statistically significantly different from the control with p-values of 1.0320x10-4 and 8.7949x10-5, respectively. Despite a significant decrease in delay time, the redesigned actuator system still has a delay greater than the normal range of stroke patients’ affected limb wrist flexion. This indicates that further design and exploration is required for a clinically ideal solution. Nevertheless, the delay reduction achieved in this project can improve many of the clinical functionalities of the Hand Mentor by better synchronizing patients’ effort with the active assistance of the Hand Mentor, as well as its extrinsic feedback.