Abstract: A mattress includes a plurality of air cells. Each cell has a low air permeability envelope and a foam inflation structure that defines one or more voids inside the low air permeability envelope. The foam inflation structures expand when unloaded to cause inflation of the one or more voids. When unloaded, the ratio of the volume of the foam inflation structure to the volume of the one or more voids within the low air permeability envelope is not the same in all the cells.

Abstract: A mattress has cells with low air permeability envelopes. Check valves permit air flow into cell groups. An inflation structure expands within the cells when not loaded to cause the envelope to fill with air through the check valves. Another mattress has a cell with a primary bladder, a hollow inflation structure in the primary bladder, a secondary bladder in the hollow inflation structure. The inflation structure expands when not under load to cause the primary bladder to fill with air through the check valve. An air cell has a bladder, a check valve permitting air flow to the bladder, and an inflation structure that expands in the bladder when not under load to cause the bladder to fill with air through the check valve. The inflation structure is a cylindrical foam structure with a portion removed along a surface and a D-shaped hollow space within an upper portion thereof.

Abstract: A bed comprises a bed frame and a bed deck supported by the bed frame. The bed deck comprises a step deck, including a lower deck, an upper deck, a side wall connecting the lower deck to the upper deck, and a recess defined by the lower deck and the side wall. The side wall at least partially surrounds the recess. A mattress comprises a safety mattress extending across the lower bed deck and having air cells including air cells resting on the upper bed deck.