Fabrication of custom contour cushion using pressure mapping method: a preliminary study

Wheelchair users commonly spent about 12 to 16 hours a day in sitting. In order to prevent pressure sore, they usually use a “pressure relief” cushion. Among all the different types of wheelchair cushions available on market, it was commonly accepted that custom made contoured cushion is very effective in pressure redistribution but rather costly to purchase. The main aim of this study was to explore the feasibility of using interface pressure data for custom contour cushion fabrication. A total of 10 able-bodied individuals of both genders were recruited in this study. They were asked to sit on a pressure mat placed at the buttock-foam cushion interface. The pressure distribution was then captured and outputted in actual physical dimension to produce a “pressure” contour map on paper. This map will serve as the template used by the “manual foam copier” to produce the required contoured cushion. The relationship between the cutting depth and the interface pressure values was calculated based on the mechanical properties of the foam material and the average pressure at the buttock/flat foam interface. The pressure relief characteristics of the contour cushion produced were then compared with commercially available foam, air and gel type cushions in terms of peak and average pressure over the ischial tuberosities, and the total buttock-cushion contact area. Preliminary results showed that a custom contour cushion fabricated with this technique had a better pressure relief characteristic than flat foam cushion, but comparable with both air and gel type cushions