Development of a Bedsore Preventive Mattress for Physically Disabled Person

Recently the number of aged person who need care is drastically increasing in the Japanese society. However the number of care worker is not increasing rather than aging of the worker is apprehensive for the society. In order to satisfy the quality of life of the aged, especially who cannot turn over their body by himself and to reduce physical labor of the care worker, we have developed a posture turnover mattress. Considering the ground, bedsore can be prevented, if the body can be turnover time to time. In fact, turnover in every 2 hours became a big physical load to a care worker where a number of disable aged person accommodated. Our mattress is consisted of a number of air chambers those are connected to an air compressor through separate solenoid valve. Independent sensors are provided for each chamber to monitor internal air pressure all the time. All these sensor outputs and the solenoid valves are connected to a control PC. If the pressure of any specific chamber changeless, the control computer will determine the non movement of the body. Therefore, the control computer will send instruction to the solenoid of the designated chamber or a combination of a chamber to be closed or to be opened. We have fabricated a waterproof poly urethane made frame and placed 12 chamber in it. Commercially avail able sensors are used to monitor pressure. In a preliminary evaluation we have investigated some properties such as comfort as a mattress, speed of the turnover. The adequateness of the number and the size of the air chambers are also investigated in order to optimize controlling parameter. As a result, the mattress is suggested comfortable and safety. However, the size and the number of the air chamber should be considered to conduct a smooth turnover.