Activity Monitors for Wheelchair Users
By Ding, Dan; PN: Paraplegia News, Vol. 65, No. 1, pp. 30-31Publication Date: January 2011
Article outlines the development of a wheelchair propulsion monitoring device (WPMD). The unobtrusive WPMD was interfaced with a context aware software package capable of recognizing different wheelchair propulsion patterns and quantifying independent mobility and upper limb usage for wheelchair propulsion and other activities of daily living. The WPMD integrates a wheel rotation datalogger clipped on the wheel that collects mobility information, and an e-Watch worn around the wrist that monitors upper limb movements. During testing of the device with 25 participants with spinal cord injury performing activities of daily living, the software was able to recognize four activity categories with more than 80 percent accuracy: self-propulsion, being pushed, sedentary upper limb activity, and non-activity. Based on the acceleration signals recorded by the e-Watch, four propulsion patterns were identified: semicircular, arcing, single-looping over, and double-looping over, with an accuracy of 60 to 90 percent. Using data collected from 29 manual wheelchair users who propelled over level tile and high pile carpet, propulsion parameters were estimated including propulsion and recovery time of each stroke based on wrist acceleration and compared with the outputs from a SMARTWheel. The estimation errors for propulsion and recovery times were 13 and 15 percent, respectively, on the tile and 9 and 14 percent, respectively, on the carpet. As for stroke duration, the average estimation error was reduced to 0 percent for both surfaces. Continued work on the WPMD is supported by the Department of Defense, the National Institute of Disability and Rehabilitation Research’s (NIDRR’s) Rehabilitation Engineering Research Centers (RERC) on Spinal Cord Injury, and RERC on Interactive Exercise Technologies and Exercise Physiology.
Assistive Products Discussed: SMARTWHEEL
Published by: PVA Publications (Website:http://www.pvamagazines.com)
Paralyzed Veterans of America (Web Site: http://www.pva.org )
