Pressure/Motion Feedback to Protect Skin of Sensorimotor Impaired Elders


Principal Investigator: Eric E. Sabelman, PhD

Project Staff: David L. Jaffe, MS; Janice Pai, BS; Eric L. Topp, MS; and Ruth Yap, MS

Project Category: Spinal Cord Injury and Other

Objective: We are testing the hypothesis that a wearable motion analysis and pressure feedback system will help prevent skin breakdown in individuals with spinal cord injury (SCI), stroke (CVA), diabetic neuropathy, prolonged post-surgical immobilization or extreme frailty who are at risk for skin breakdown (i.e. pressure sores). Past projects have led to the creation of a computerized wearable motion analysis system ("WAMAS") for use as a diagnostic and therapeutic device in elder care.

Research Plan: Testing will be done with 12 subjects in three categories having different skin care needs: (a) SCI patients referred by VAPAHCS Spinal Cord Injury Center, (b) frail elderly nursing facility residents (from VAPA Long-Term Care), and (c) peripheral neuropathy patients (from VAPA Neurology Service). Pressure relief motion data will be collected using the WAMAS system equipped with triaxial silicon accelerometers (± 5 g range) near the critical skin region (e.g.: trunk and head for wheelchair pressure relief, leg for diabetic gait) with pressure sensors embedded in clothing or cushions.

We are assembling additional sets of the 2nd-generation WAMAS. Modules were fabricated for skin interface pressure input, tactile, and speech outputs; work on the arm-mounted RF-linked operator unit is continuing. Motion patterns of pressure-relief activities are scored for correct vs. incorrect performance by dividing them into a time sequence of segments, each with a duration and value window.

Work Accomplished: During 2002, initial and repeat data acquisition trials were done for five Long-term Care subjects (two cannot transfer independently, two can transfer to wheelchairs, and one can ambulate using a walker), with the assistance of Stanford BME student Janice Pai and Cornell summer student Jong-Min Park. The former studied rolling onto the side while the subject is lying in bed; the latter student studied reaching tasks while the subject is supine or with bed elevated to a semi-sitting position. Trials with these subjects of computer-generated speech commands compared to live voice showed acceptable equivalence in time to initiate and complete a roll-to-side pressure relief maneuver.

Because no peripheral neuropathy subjects were referred to the study, data acquisition and feedback trials were conducted on a cohort of 4 Parkinson's Syndrome patients selected for frequent episodes of motor block. WAMAS-based Parkinson's Disease diagnosis and therapy is predicated on detecting freezing episodes and producing a stimulus signal at an appropriate time to help unlock freezing, so as to reduce delay in initiation of the intended motion.

Since not all 12 subjects in each category were recruited, a no-cost extension of this project (scheduled to end 12/31/02) is being requested so that testing can continue. Extension would facilitate technology transfer activities, which have been increasing rapidly during the last two months, with the aid of Stanford University Office of Technology Licensing.

Expected Outcome: Prospective use the WAMAS as an element of telerehabilitation systems for home health care of individuals at risk for skin damage prompted a special session on "Emerging Role of Telemedicine in Home Healthcare for the Elderly,"at the RESNA 25th International Conference on Technology & Disability (July 1, 2002, Minneapolis, MN). The session was introduced by presentation of the evolution of the WAMAS concept from a local motion-sensing device to home-based monitoring with remote reporting. A follow-up session at the 2003 RESNA conference is planned.

Funding Source: VA RR&D Merit Review

Funding Status: Funded

Reprinted from the 2002 Annual Report