An air-filled mattress with virtually no air loss has a plurality of air-filled bags grouped into zones of uniform air pressure. A controller monitors the air pressure in each zone and activates a blower to adjust the pressure in any zone in which the measured pressure differs from the desired pressure...http://www.google.fr/patents/US5235713?utm_source=gb-gplus-shareBrevet US5235713 - Fluid filled flotation mattress
