Head-Mounted Vibrotactile Prosthesis for Patients With Chronic Postural Instability

The goal of this study is to evaluate a tactile prosthesis that provide individuals who have demonstrated chronic imbalance with help to maintain a correct sense of orientation with respect to the gravity and improve posture control. Chronic imbalance leads to significant problems. This study is designed to evaluate a device which can potentially improve the balance of these patients.

The participant will be asked to come to Washington University on three occasions for approximately 2 hours. Between visits, they will be asked to use the device daily (intervention condition) or to not use the device (control condition) for a prescribed period of time doing different activities. They will be provided written instructions from a physical therapist that will be determined by their individual ability. The activities will be typical exercises that are given to people with balance disorders. After 6 weeks of home use, participants will return for the second visit, and will repeat the evaluation. They will then return home and complete the either the control or intervention condition (which was not done the first time) in a crossover design.

On their first visit (week 0; baseline) participants will be asked to complete the same kind of tests that evaluated the function of their balance system at the time of their diagnosis. They will have their eye movements recorded using goggles and an infra-red camera while the prosthesis is in place and providing vibration feedback. Computerized Dynamic Posturography (CDP) testing will require them to stand on a platform and perform tests (20 seconds each) with their eyes open or closed, with the platform moving or still, and/or with the visual surround either stable or moving. They will be fitted with a safety harness that will keep them from falling. Next the investigators will evaluate their ability to perform movement tasks while walking (walking down the hall, walking down the hall avoiding objects, changing speeds while walking, going up and down stairs etc). They will walk a 25-foot distance at a comfortable gait speed, and again at a maximum gait speed. Lastly, they will be asked to fill out questionnaires.

On their second and last visit, they will repeat the evaluations that were performed during the first visit.

Inclusion criteria

• Ambulatory
• Chronic imbalance for at least 1 year
• Have reached a functional performance plateau with respect to balance performance
• Have a DGI score of <19
• Fall below age and gender matched normative data for gait speed

Exclusion criteria

• Subjects who are unwilling or unable to adhere to all study requirements, including completion of the training period, evaluation tests, and return to clinic for a follow-up visit.
• Women who are pregnant (women will self-report possible pregnancy).