Alternating low air loss pressure overlay for patient bedside chair

An alternating pressure air sac overlay for therapeutic treatment of an immobile patient's skin while seated in a chair having legs, comprising:

• an array of elongated independently sealed air sacs constructed of an airtight material, sized in length to fit across a standard chair, said individual air sacs being tubular in shape, mounted in a fixed side-by-side array, the overall longitudinal length of the air sac array being sized to fit at least on the chair seat of a chair, a first group of independent air sacs being separated by a second group of air sacs in a side-by-side array, so that every other one of said air sacs in said first group and every other alternating one of said air sacs is contiguous with said first group to form said second group of air sacs;
• first conduit manifold connected to said first group of air sacs;
• second conduit manifold connected to said second group of air sacs;
• an air pump having an inlet and an outlet for providing pressurized air in fluid communication and connected to said first conduit manifold and said second conduit manifold;
• controllable air inlet valve means connected to said air pump and said first conduit manifold and said second conduit manifold, whereby in a first position, said air inlet valve means provides air pressure only to said first conduit manifold from said air pump, and in a second position, provides air under pressure only to said second conduit manifold from said air pump;
• means including timing circuits for controlling air in a timed sequence into said first conduit manifold and said second conduit manifold from said air pump connected to said air pump;
• electrical power supply connected to said air pump;
• and
• said timing circuits connected to said electrical power supply and said means for controlling air in a timed sequence;
• at least two straps, said first strap and said second strap connected to an edge portion of said air sac array overlay for connecting said air sac array overlay to said chair legs for attaching and stabilizing the air sac array overlay to a chair;
• and
• a coverlet comprising a liquid impervious barrier means removably connectable to said air sac array, covering said air sac array to provide a protective shield against liquids reaching said air sac array.