Blind spot sensor systems for power wheelchairs: obstacle detection accuracy, cognitive task load, and perceived...

Blind spot sensor systems can improve power wheelchair (PWC) safety. This research (1) compared accuracy of obstacle detection in the rear of a wheelchair with and without a sensor system, and (2) explored cognitive task load and perceived usability, safety, confidence and awareness in a laboratory setting, and (3) PWC users' perceptions in real-world settings.

A mixed-method design was used. PWC users were provided with the sensor system. In laboratory accuracy of obstacle detection with and without a sensor system, cognitive task load and perceived usability, safety, confidence and awareness were evaluated. Participants then used the sensor system at home for two-months before completing semi-structured interviews. Statistical and thematic analyses were conducted.

Among 11 PWC users (age = 67.5 ± 7.5y), obstacles were detected more accurately with sensor system than without (p < 0.001). Using the sensor system required lower cognitive task loads (p = 0.005). The system was perceived by most users as easy to use (9/11) and its capabilities meeting their requirements (8/11). Most users did not perceive safety (9/11), confidence (9/11) or increased awareness (10/11) in the laboratory. Three themes emerged in the follow-ups: perceived usefulness, barriers to use, and recommendations. Four participants reported continued use after 2 months, reporting perceived increased awareness, convenience, and independence using the system. Those who discontinued use reported perceived lack of usefulness and technical issues. Recommendations included types of users who can benefit and sensor improvements.

Sensor systems may improve obstacle detection accuracy while reducing cognitive task load. However, larger scale implementation should consider recommendations for PWC service provision.IMPLICATIONS FOR REHABILITATIONBlind spot sensors systems increased speed and accuracy of obstacle detection when using a power wheelchair.Technical and hardware issues encountered by PWC users highlight the need for training and support services.Technical support was out of scope for the current research project and will be explored in future research given the critical role it might play in the usability and adoption of assistive technologies.PWC users perceived there to be practical uses for blind spot sensor systems.