Isometric Controls with Personalized Algorithms for Driving Electric Powered Wheelchairs

Principal Investigators: Donald Spaeth, PhD, RET; Rory A. Cooper, PhD

Co-Investigators: Michael L. Boninger, MD; Dan Ding, PhD; Karl Brown, PhD; Diane Collins, PhD, OTR/L

2004-2007

This three year Merit Review grant will investigate best clinical application of power wheelchair controls for individuals with multiple sclerosis. This work will build on HERL’s prior investigations with isometric W/C controls by providing both personalized algorithms for disambiguation of unintentional hand movements such as tremor and progressive increases in gain during the day to counteract the effects of fatigue - a frequent occurrence with this population.  Another objective is to determine whether isometric (Force sensing) input, movement sensing input or some combination thereof (variable compliance) best enhances control performance. 

Phase one testing will be conducted in a virtual environment in which the subjects will practice driving an iconic wheelchair on a computer screen.  During phase II, subjects will drive their personal wheelchair in HERL’s activities of daily living laboratory while using the controls that were “tuned” during Phase I.

Protocols and Informed consents approved by local IRB.  Virtual Wheelchair Driving Software is operational and has been tested and calibrated.  To reduce subject hardship, the protocol was revised to reduce the number of required visits in October 2006.  Between December 2006 and February 2007, five subjects were recruited and test by master’s candidate Karl Brown.  Due to recruitment difficulties, the protocol was modified again in May 2007 to increase the spectrum of eligible subjects.  We continue to keep the protocol open and are actively recruiting additional subjects.