Patent ID: 8836515

Claim:
A device for continuously monitoring an angular elevation, α, from horizontal of a bed backrest against which a backbody of an individual may lean, to provide an automatic notification in the event the angular elevation, α, falls below a prescribed value, the device comprising: (a) a liquid column of substantially incompressible fluid open to the atmosphere at an upper-end, said liquid column contained by a length of flexible inner tubing encased by an elongated flexible outer housing extending along at least a substantial portion of said inner tubing length, and a gas permeable membrane over said opening; (b) a pressure transducer located along said liquid column to take measurements of pressure of the liquid column dependent on the angle of elevation at a position other than said upper-end, said pressure transducer in communication with a computerized unit having at least one alarm for communicating the automatic notification; (c) an entry port into said length of said flexible tubing having an open state permitting manual entry of said liquid into said flexible tubing, and a closed-shut state; and (d) a first securing mechanism for attachment of at least the upper-end to the bed backrest, and a second securing mechanism for attaching said position other than said upper-end to a seat interconnected with the backrest whereby the bed backrest may be retrofitted with said device, the flexible inner tubing and flexible outer housing conforming to attachments points on said bed backrest afforded by the flexibility of both the inner tubing and outer housing.