Prototype development and comparative evaluation of wheelchair pressure mapping system.
Wheelchair pressure mapping devices used in the prescription of seat cushions and postural supports have been limited in durability, data presentation, and/or clinical efficiency.  This project sought to establish the ideal specifications for clinically useful pressure mapping systems, and to use these specifications to influence the design of an innovative wheelchair pressure mapping system (Tekscan "Seat").  Technology, previously developed for measurement of forces of dental occlusion and of the foot during gait, was applied to wheelchair seat mapping.  Tests were designed to compare the performance of three pressure mapping systems: the Tekscan system, the FSA system, and the Talley TPM3.  Bench tests were done to measure reproducibility, hysteresis, and creep of each of the pressure mapping systems.  A contoured loader gauge was developed to test for the influence of hammocking.  Tests were also performed using spinal cord-injured subjects to demonstrate the relative performance of the pressure mapping systems in a clinical setting.  A focus group session was conducted with seating specialists to review the strengths and weakness of the systems for routine clinical use.  The TPM3 was found to be the most accurate, stable, and reproducible but limited in ease of use, speed, and data presentation.  FSA was rated well in clinical application and data management but demonstrated a pronounced hysteresis (+/-19%) and creep (4%).  The Tekscan system also showed substantial hysteresis (+/-20%) and creep (19%) but was preferred by clinicians for its real-time display capabilities, resolution, and display options.  Some trends in system performance on varied support surfaces were identified and can be a valuable guide to interpretation of measurements and prescription decision making in the clinic. Problems identified with the accuracy and stability of the Tekscan and FSA systems may be amenable to resolution with software correction and changes in fabrication.  With these improvements all three systems show the potential to be useful clinical tools.
Ferguson-Pell
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Center for Rehabilitation Technology, Helen Hayes Hospital, West Haverstraw, New York 10993.
Cardi
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D003258:Consumer Behavior; D004867:Equipment Design / Q000295:instrumentation / Q000379:methods; D005069:Evaluation Studies as Topic; D006801:Humans; D011312:Pressure; D011795:Surveys and Questionnaires; D016474:Weight-Bearing; D014910:Wheelchairs