A water-mat including water in the baggy mat was developed for persons in need of nursing care. A flow of water in this mat is controlled by the positions, sizes, number and shape of some weirs and some orifices in the water-mat. This mat is designed to have a good body pressure distribution and to follow smoothly the posture of patient. Now we already developed a lightweight water-mat including liquid with flexible materials. This lightweight water-mat is however, too heavy for elder people to use more easily. If more lightweight water-mat can be developed and good body pressure distribution at high back raising angle can be accomplished, more people can use it in home care. So we developed more lightweight and new form water-mat including liquid with flexible materials We call this new water-mat as the discrete type. We verified the pressure dispersion of the lightweight discrete type water-mat by comparing it with the lightweight water-mat until now and the marketed bedsore prevention mattiess.
