Applications of vibrotactile display of body tilt for rehabilitation.

Body-mounted motion sensors have been shown to decrease subject sway when a tilt estimate is fed back to the user by means of an array of tactile vibrators which display estimated tilt magnitude and direction. Vestibulopathic subjects who are tested using computerized dynamic posturography show significantly reduced sway in both the sensory motor and the motor control portions of that test. This result suggests potential application as an assistive balance aid. Another potential application of vibrotactile tilt feedback is in rehabilitation. Two lines of research have yielded promising, albeit very preliminary, supporting results. The first of these is the response of subjects to a toes-up pitch maneuver. At critical pitch velocities, vestibulopathic subjects are unable to maintain stability during or after a perturbation without tilt feedback, but are able to stand when feedback is provided. The second line of research involves perturbations during locomotion. Vibrotactile tilt feedback again reduces subjects sway. Preliminary results of both of these on-going experiments indicate that this increase in performance may be retained.