Design and Preliminary Testing of MOVit: a Novel Exercise-Enabling Control Interface for Powered Wheelchair Users

Abstract

The sedentary lifestyle of powered wheelchair users has a deleterious effect on their health. If they could exercise while driving their chair, like many manual wheelchair users do, they could potentially improve their health through integrated daily exercise. This paper presents the development of MOVit, a novel, arm exercise-enabling, wheelchair control interface, and the results of three preliminary tests with unimpaired subjects. MOVit consists of two custom-made, instrumented mobile arm supports that replace the armrests of a normal powered wheelchair. Instead of using a joystick to drive the wheelchair, the user moves the arm supports with their arms using a cyclical motion, while the software simulates a “virtual lever drive” chair. MOVit was first tested in a stationary setting with five unimpaired individuals (two expert users and three naïve users) to determine if they could achieve increasing levels of exercise by increasing movement amplitude and frequency. Secondly, driving performance using MOVit was evaluated with the same subjects on a long, straight track. Third, maneuverability with MOVit was evaluated for the expert users. In the stationary setting heart rate and oxygen consumption significantly increased as the level of exercise intensity increased. Driving performance for the long, straight track was comparable to the performance achieved using a standard joystick for the two expert users but was worse for the three novice users due to poor clutching inefficiency. The expert users achieved a level of maneuverability with MOVit comparable to that with a joystick. In conclusion, MOVit can modulate exercise intensity during powered wheelchair driving with a maneuverability comparable to that achieved with a standard joystick.