Development of a Prototyping System for Custom-Contoured Foam Cushion Using the Pressure Mapping Method

For people with limited mobility such as wheelchair users, prevention of pressure sore is an important health care issue. To relieve pressure at buttocks, foam cushion enveloping specific contour matching with an individual's buttocks has commonly been employed. This paper presents a prototyping system that generates custom-contoured foam cushion using the pressure distribution at the buttock–cushion interface. Based on the load–deformation characteristics of the foam material, this pressure distribution is converted into the corresponding deformation of the foam. A surface smoothing process approximates all discrete data points into a bi-cubic surface. ASCII NC codes are then generated for CNC fabrication of the cushion with the desired surface contour. This study integrates commercially available products into a fully automated system and can be readily implemented by seat/wheelchair cushion manufacturers.