Comparison between joystick- and gaze-controlled electric wheelchair during narrow doorway crossing: Feasibility study and movement analysis.

Due to motor deficiencies inducing low force capabilities or tremor, many persons have great difficulties to use joystick-operated wheelchairs. To alleviate such difficulties, alternative interfaces using vocal, gaze, or brain signals are now becoming available. While promising, these systems still need to be evaluated thoroughly. In this framework, the aims of this study are to analyze and evaluate the behavior of 11 able-bodied subjects during a navigation task executed with gaze or joystick-operated electric wheelchair involving a door crossing. An electric wheelchair was equipped with retroreflective markers, and their movements were recorded with an optoelectronic system. The gaze commands were detected using an eye tracking device. Apart from classical, forward, backward, stop, left and right commands, the chosen screen-based interface integrated forward-right and forward-left commands. The global success rate with the gaze-based control was 80.3%. The path optimally ratio was 0.97 and the subject adopted similar trajectories with both systems. The results for gaze control are promising and highlight the important utilization of the forward-left and forward-right commands (25% of all issued commands) that may explain the similarity between the trajectories using both interfaces.