Patent ID: 7418751

Claim:
An apparatus for measuring the angular position of a patient support surface relative to gravity force, comprising: a patient support comprising a first side and a second side; a first turning bladder proximal to the first side of the patient support; a second turning bladder proximal to the second side of the patient support; a first guard bladder proximal to the first side of the patient support; a second guard bladder proximal to the second side of the patient support; an angle sensor associated with said patient support and having an output responsive to changes in said angle sensor's position relative to gravity force, said angle sensor being oriented in a manner such that said output relates to the angular position of said patient support relative to the direction of gravity force; and a processor configured to receive and process the output from the angle sensor, wherein the processor is configured to control the inflation and deflation of the first and second turning bladders and of the first and second guard bladders such that the first turning bladder and the second guard bladder are inflated concurrently and the second turning bladder and the first guard bladder are inflated concurrently.