Adjustable sheet for intelligent seating system

A proper seating is important as an aid for cerebral palsy patients, and has good influence on patients´ physical conditions and mentalities. Deformity of spine causes gaps between their backs and backrests of wheel chairs. Generally, urethane cushions are used to fill up the gaps. However, this method cannot handle their dynamic motion that will happen in daily life. In the previous study, we developed the first prototype of the intelligent seating system (i-Seating 1) by using a conventional adjustable-belt type seating and some air bags on the belts. We could control the posture and pressure of users, but there is a severe limitation for real situations. In this paper, we propose to use an adjustable sheet mechanism for the wheelchair seating. The adjustable sheet mechanism is very simple and a combination of a main sheet and adjustment belts. We installed this mechanism in the conventional adjustable-belt type seating. For convenience of the adjustment, we also developed a back-shape measurement system and proposed an adjustment method on the basis of the measurement results. Finally, a validation test was conducted and evaluated. The experimental result indicated that the adjustable sheet fit to the complex back shape and controlled a good posture and even pressure for a dummy deformed backbone.