Preliminary Design of an Activity TeleMonitor for Wheelchair Users

Juan Jose Vazquez, MS, Dan Ding, PhD, Rory A. Cooper, PhD
Department of Rehabilitation Science and Technology, University of Pittsburgh
5044 Forbes Tower, Pittsburgh, PA 15260
Human Engineering Research Laboratories, VA Pittsburgh Healthcare System


This paper describes the preliminary design of an Activity TeleMonitor (ATM) system targeting wheelchair users. The ATM system is comprised of two separate parts: a wheelchair-mounted unit (WMU) and a stationary unit at a remote host station. The WMU incorporates a number of sensors to measure parameters related to wheelchair usage and activity, safety, and context of use. It provides continuous collection and evaluation of multiple activities, intelligent detection of emergency and abnormal behaviors, and a cellular connection to a remote host station. The stationary unit at the host station allows clinical professionals to access the incoming data from the WMU, examine usage patterns and abnormal behaviors, and make requests of modification to the sensor limits and data transmission. The hardware and software implementation are introduced in details, and bench testing results especially on the cellular communication capacity are presented. Repeated trials of data transmission, telephone request for data transmission, telephone request for sensor threshold modification, alert detection and transmission received 100% success rates. The transmission rates were measured, averaging from approximately 20 seconds for command transmission to 46 seconds for 3Kb data retrieval. Overall, the prototype system could potentially supplement information from direct interviews and surveys, and provide objective information about a user’s activity and performance within the natural environment. Future work will focus on add more sensors, new algorithms to detect contexts, social interaction, and emergency conditions. Packaging and installation will be investigated. Finally, the system will undergo rigorous bench testing before it is tested with wheelchair users in their home and community.


Wheelchair, activity, safety, telemonitor, cellular communication


The work is supported by PVA 2264-01, and VA Center of Excellence for Wheelchairs and Associated Rehabilitation Engineering B3142C.

Author Contact Information:

Juan Jose Vazquez, Human Engineering Research Laboratories, VA Pittsburgh Healthcare System 151R1-H, 7180 Highland Drive, Pittsburgh, PA 15206. 412-365-4850,