Year, Volume, Issue, Page(s):17, 29, 4, 202-209
Study demonstrated the feasibility of a device for monitoring pressure relief maneuvers and physical activity for wheelchair users. The device counts the number of wheel pushes based on wheelchair acceleration and measures pressure relief maneuvers using a seat sensor consisting of three force sensing resistors. To establish the feasibility of the seat sensor for the detection of pressure relief maneuvers, 10 wheelchair users and 10 non-disabled controls completed a series of wheelchair depression raises, forward trunk leans, and lateral trunk leans. The seat sensor was placed underneath the user’s seat cushion. To establish the feasibility of wheel push counting, 10 full-time wheelchair users navigated a flat 50-meter outdoor track and a 100-mer outdoor obstacle course during self-propulsion (e.g., wheel pushes) and during assisted-propulsion (e.g., no wheel pushes). Of the 240 pressure relief maneuvers performed, 225 were properly classified by the seat sensor (94 percent accuracy, 96 percent sensitivity, 80 percent specificity). Sensitivity was highest for depression raises (98 percent) and lowest for front lean maneuvers (80 percent). The wheelchair activity monitor measured 2,112 pushes during the self-propulsion trials compared to 2,162 pushes measured with the instrumented push-rim (97.7 percent). During assisted-propulsion trials, there were 477 incorrectly identified pushes (8.0 per trial). This study demonstrated the feasibility of monitoring pressure relief maneuvers and physical activity during self-propulsion and assisted-propulsion for wheelchair users using a simple technology.