Development and evaluation of two control methods for MOVit: An exercise-enabling driving interface for powered wheelchair users
The sedentary lifestyle of powered wheelchair users has a deleterious effect on their health. If they could exercise while driving their chair, they could potentially improve their health through integrated daily exercise. This dissertation presents the development of MOVit, a novel, arm exercise-enabling, wheelchair driving interface. MOVit consists of two custom-made, instrumented mobile arm. Instead of using a joystick to drive the wheelchair, the design goal was that the user moves the arm supports with his arms through a cyclical motion to drive the chair, like a “virtual lever drive” chair. We developed and studied two different methods for driving and clutching, compared to driving performance with a Standard Joystick. In the Squeeze and Height Clutch methods, the driver clutched the virtual levers by squeezing a handle or moving the arm support above a line, respectively. A total of 24 unimpaired subjects were randomized to one of the three control methods and performed a series of driving tests across two consecutive days in a 3D wheelchair simulator and in reality. The results showed that, after learning, the MOVit driving performance with Squeeze and or Height Clutch control was comparable to Joystick control. We also found that subjects exhibited good overnight retention of learned driving abilities and transferred their abilities readily from the virtual training environment to the real environment. These results show for the first time the feasibility of a maneuverable, exercise-enabling powered wheelchair driving interface.