Closed loop feedback air supply for air support beds
First Claim
1. In a low air loss air support convalescent bed having a plurality of low air loss air sacs that are maintained within a desired pressure range and are arranged for supporting various body sections of a patent, the improvement comprising:
- (a) air supply means for supplying compressed air at a pressure in excess of said desired pressure range of any of said air sacs;
(b) air distributing means for distributing compressed air from said air supply means to said plurality of air sacs;
(c) pressure control means having a plurality of manually set pressure control valves for conducting air at preset pressure ranges to individual air sacs, each of said manually set pressure control valves having a fixed orifice of selected diameter;
(d) pressure monitoring means directly and continuously monitoring the air pressure of only a selected one of said plurality of air sacs and providing pressure indicative signals; and
(e) feedback means receiving said pressure indicative signals and providing pressure signals to said pressure control means, said pressure control means adjusting a master servo valve to maintain the proper pressure range throughout the bed,whereby a selected pressure between the air sacs and the patient is established.
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Accused Products
Abstract
A closed loop feeback-controlled air supply system for air support convalescent beds having groups of air sacs for supporting various body sections of a patient. The air supply system may be self-contained with its own air supply compressor or it may utilize any other source of compressed air. The air supply is coupled with a distributor manifold from which extends a plurality of air supply lines extending to selected groups of air sacs. Servo valves controlling each of the air supply lines are automatically positioned and controlled by signals from a microprocessor, the microprocessor receiving pressure feedback monitoring signals from pressure transducers associated with each of the groups of air sacs. Between the air supply and the manifold may be provided a master control valve which may be a servo valve also activated and controlled by the microprocessor responsive to feedback signals. Where the air supply is provided by a variable speed compressor, the compressor may also be responsive to control signals from the microprocessor.
115 Citations
10 Claims
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1. In a low air loss air support convalescent bed having a plurality of low air loss air sacs that are maintained within a desired pressure range and are arranged for supporting various body sections of a patent, the improvement comprising:
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(a) air supply means for supplying compressed air at a pressure in excess of said desired pressure range of any of said air sacs; (b) air distributing means for distributing compressed air from said air supply means to said plurality of air sacs; (c) pressure control means having a plurality of manually set pressure control valves for conducting air at preset pressure ranges to individual air sacs, each of said manually set pressure control valves having a fixed orifice of selected diameter; (d) pressure monitoring means directly and continuously monitoring the air pressure of only a selected one of said plurality of air sacs and providing pressure indicative signals; and (e) feedback means receiving said pressure indicative signals and providing pressure signals to said pressure control means, said pressure control means adjusting a master servo valve to maintain the proper pressure range throughout the bed, whereby a selected pressure between the air sacs and the patient is established. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of maintaining and adjusting inflation of the air sacs of a low air loss air support convalescent bed having multiple air sacs forming a plurality of air sac groups, comprising:
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(a) supplying air from a source of compressed air having air pressure exceeding the maximum expected air pressure desired for any of said air sacs and at a volume exceeding the cumulative air loss from said air sacs; (b) distributing by a control means compressed air to a plurality of air supply ducts, each air supply duct being in communication with one of said respective air sac groups; (c) controlling by said control means a master servo valve, thereby controlling the pressure and volume of air flowing through each of said air supply ducts to the respective air sacs in communication therewith; (d) sensing the air pressure in a selected one of said air sac groups and proving pressure indicating signals for said selected one of said air sac groups representing said air pressure within said selected air sac group; and (e) receiving and electronically processing said pressure indicating signals and transmitting control signals to said control means responsive to said pressure indicating signals for automatic adjustment of said master servo valve thereby controlling the respective air pressures of said air sacs. - View Dependent Claims (10)
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Specification