Jack Hougen Petajan
Physician in Salt Lake City, UT

5197461, Mar 30, 1993

Aug 12, 1991

7/743730

Jack H. Petajan - Salt Lake City UT
Stephen R. Topaz - Salt Lake City UT

University of Utah Research Foundation - Salt Lake City UT

A61F 534

1281181

This invention provides a pressure sensitive inflatable orthopedic pillow for therapy which comprises an inflatable bladder, an air switch in fluid communication with the bladder via a gas feedline, and an air supply which provides a constant stream of air to the air switch. The air switch includes an atmospheric pressure inlet, a connector tube through which overflow air is returned from the bladder to the air switch, and an exhaust outlet. The inflatable bladder is cyclically inflated and deflated without outside control means, the cycle beginning with inflation of the bladder by directing a stream of air provided by the air supply through the air switch into the bladder until the bladder is inflated. The cycle ends with deflation of the bladder by directing an overflow stream of air from the inflated bladder into return conduit to be returned to the air switch, whereupon the stream of air provided by the air supply is diverted into the exhaust outlet by the overflow stream of air and by air thereafter forced out of the bladder by negative air pressure. Alternatively, an electrically or mechanically controlled pressure sensor measures pressure within the inflatable bladder.