DEVELOPMENT AND EVALUATION OF A SMARTPHONE VIRTUAL SEATING COACH APPLICATION TO FACILITATE POWERED SEAT FUNCTION USAGE FOR POWERED WHEELCHAIR USERS

摘要

Powered wheelchairs with powered seat functions (PSFs) are prescribed for wheelchair users who are unable to adjust their postures or manage their seating pressure independently because of motor and/ or sensory impairments. However, a novice powered-wheelchair user might not have appropriate or sufficient training on using PSFs due to the limited time in clinics or complex situations in real-life environments. The Human Engineering Research Laboratories have developed the Virtual Seating Coach (VSC) which records PSF usage and reminds users to adjust their PSFs.udThis research project was to develop a smartphone virtual seating coach (SVSC) and investigate several improvements. The SVSC used low-cost accelerometers to detect the seating angles which decreased the complexity of the sensor installation. By using the smartphone for information display and integrating the electronic components into the phone holder, the SVSC significantly decreased the dimension and increased the clearance of the whole system. A usability study has been conducted from five powered wheelchair users and five rehabilitation professionals to gather their feedback and refine the SVSC.udIn order to overcome the limitation of the internal storage in the system and enable the PSF usage to be reviewed by clinicians in real time, a prototype web service was constructed for data storage and data visualization. This web service allowed the SVSC to upload the daily PSF usage data from different users and provided the longitudinal PSF data plots for review.udTen powered wheelchair users were recruited for a three-week in-home trial to evaluate the effectiveness of SVSC. The compliance rate of performing repositioning exercise has increased around 44% after the intervention of the SVSC. The results also show that the users’ attention and decision toward the reminders can be predicted by context factors collected from the smartphones’ sensors (around 80% and 75% accuracy respectively). Furthermore, the negative correlation between the frequency of using PSFs and the wheelchair discomfort indicate the need for dynamic seating posture and suggested that the SVSC could implement this functionality to remind users to change their seating angle periodically to improve wheelchair comfort.