LOW AIR LOSS SUPPORT APPLIANCE

Abstract: A support appliance which is adapted to be supported on a bed frame and comprises a plurality of elongated inflatable air sacs (1). The air sacs (1) are mounted in groups, and extend transversely of the appliance so as to provide a surface for supporting a person thereon. The appliance has a series of connected box-shaped housings (A to E), each housing being associated with a group of air sacs (1), and each comprising a pair of tubular longitudinal members (2 and 3). Air is supplied to, or exhausted from, the sacs (1) by the tubular members (2 and 3). A panel joins the tubular members (2 and 3) to provide a smooth, obstruction free surface (15). The housings of at least one pair of adjacent housings are hinged together.

Description: Low Air Loss Support Appliance This invention relates to a support appliance of the kind in which a person is supported on a plurality of inflated air sacs. British Patent Specification No. 1442994 describes a bed of the above kind in which a plurality of inflatable elongated sacs are arranged transversely of the bed on support members extending parallel to and beneath the sacs. Means are provided for admission of air to the sacs through the support members while maintaining an air tight seal between the sacs and the support members. Experience in the field with beds of this kind have shown them to be very effective for use in nursing patients afflicted with bed sores, burns or other lesions. Continuing experience with this type of support appliance has highlighted two problems which occasionally arise during use. The first of these problems arises from the fact that the beds are frequently used to nurse seriously sick patients who may be incontinent and it is accordingly often difficult to keep the bed free from waste matter, urine, dirt and food which can lodge in crevices in the bed. Although in practical embodiments the inflatable bags are removable for laundering it has been difficult, particularly where the beds are provided with head and foot bellows for contouring the surface to avoid the presence of crevices and angled surfaces, where dirt and waste matter can be trapped. O PI Another restriction in the use of the beds has been their bulkiness, even when the air sacs are removed and this bulkiness has restricted the use of the support appliances particularly for home nursing and generally for transportation. According to the present invention there is provided a support appliance adapted to be supported on a bed frame and comprising a plurality of elongated inflatable air sacs, mounted in groups and extending transversely of the appliance so as to provide a surface for supporting a person thereon, the appliance comprising a series of connected box-shaped housings, each housing being associated with a group of air sacs and each comprising a pair of tubular longitudinal members, through which air is supplied to or exhausted from the sacs, and a panel joining the tubular members to provide a smooth, obstruction free surface, wherein the housings of at least one pair of adjacent housings are articulatedly joined together. The articulated joint(s) permit the appliance to be folded back on itself for transportation. In a preferred arrangement, the -appliance further comprises means for supplying air to the tubular members, said means comprising flexible conduits passing through the housings from a manifold mounted at one end of the appliance. Advantageously, air is supplied to the tubular members on one side of the apparatus and exhausted from corresponding tubular members mounted on the other side of OMPI the housings. Preferably, a compensator valve is located in each housing in the vicinity of a tubular member through which air is exhausted from the respective group of air sacs and arranged to maintain the rate of flow of air through the group of sacs within predetermined limits. The housings may be fabricated by cross-members which join the tubular members and panels which bridge the tubular members and provide a flat, unobstructed surface which is pierced only by orifices for feeding or exhausting air from the air sacs. The housings of each pair of adjacent housings may be articulatedly joined together, to allow the appliance to take up a desired contour. Advantageously, a bellows is housed within one or both of the terminal housings of the appliance, and flexible conduits are provided to conduct air thereto and actuate the bellows, the articulated joint between the or each terminal housing and the adjacent housing permitting the appliance to be contoured in response to the operation of the bellows. The bellows, which may be air operated, can be used to contour the appliance. In practice, bellows will be located within the housings supporting the head and/or feet of the user. These bellows may be actuated by electrically or air-operated valves which are preferably located within the housings. Preferably, one of the terminal housings (the housing supporting the head of the user) is constituted by two box- shaped housing sections rigidly connected together, each housing section being associated with a group of air sacs, and each comprising a pair of tubular longitudinal members. OMPI Alternatively, the housing may be a single-section housing. Other features of the support appliance of the present invention will become apparent from the following description and accompanying drawings. One embodiment of a support appliance in accordance with the invention will now be described by way of example with reference to the accompanying drawings, in which Figure 1 is a plan view of a bed intended for support by an independant bed or frame and showing some air sacs in position; Figure 2 is a schematic side elevation, of the bed shown in Figure 1; Figure 3 is an end elevation of the bed shown in Figures 1 and 2 (but on a larger scale); and Figure 4 is a plan view similar to Figure 1 except that the air sacs have been removed and the interior of parts of the bed are shown. Referring to the drawings, a patient support surface is provided by a plurality of inflatable air sacs 1 (of which only -four are shown for clarity) which are arranged transversely of the bed in the manner described in the above mentioned prior patents. These air sacs are preferably manufactured from a micro porous material which is non-permeable to air but is permeable to water vapour. n example of suitable material is a micro porous polyurethane-coated nylon. The air sacs 1 are inflated by air supplied through tubular frame members 2 and exhausted through similar members 3 on the opposite side of the bed. Air is passed through the air sacs 1 in order to regulate the temperature of the bed, and to help maintain the temperature of the patient at a desired level. This air flow also removes water vapour from the air sacs 1. The air sacs are connected to holes 4 and 5 (only some of which are shown by way of example in Figure 1) by connectors of the kind shown in Figures 5 to 8 of European Patent Application publication No. 0034954, which enable the air sacs to be connected or disconnected very rapidly. The air sacs 1 are normally all of the same height, typically 25 to 30 centimetres high and 76 centimetres long, but it may be desirable to provide bags of different heights e.g. up to 46 centimetres high, and to arrange these bags transversely of the bed in order to give a contoured surface when the bed is in a flat position. Also, shaped bags may be employed. For example, bags of generally U-shaped form may be incorporated in the central or seat section so that the bed pans or similar devices may be placed within the bed. Conveniently, the connectors of the bags are moulded from a coloured plastics material which gives a colour code for the size or shape of the bags. The bed comprises five sections. A, B, C, D, and E, each section having separate tubular members 2 and 3, constituting header chambers for feeding and exhausting air from a group of bags. Sections A and B are rigidly connected while the other three sections C, D, and E are articulatedly connected to adjacent sections by nylon hinges 6, 7 and 8. Each section (or in the case of sections A and B) each group of sections are formed from a pair of longitudinal tubular members 2 and 3 which serve as chambers for supplying and exhausting air from the sacs. Frames are formed by welding transverse members 11 and 12 to members 2 and 3 and resulting frames are strengthened by longitudinal struts 13 which are welded to the members 11 and 12. In order to provide a smooth readily cleanable surface to each section, a sheet metal or plastic panel is attached to each of the frames formed by members, 2, 3, 11, 12 and 13. In this way, the individual sections are constructed as box-shaped housings which are open in the downward direction. In the case of sheet metal panels this is conveniently achieved by folding the transverse ends of the sheet metal panels over the members 2 and 3. Thus the upper surfaces 15 of the individual sections A, B, C, D and E provide a flat, easily cleaned and obstruction fee surface. The base of the bed is provided by a base board which in the construction illustrated is formed by a pair of panels 17 and 18 which are conveniently manufactured from metal or plastic laminated wood and which are hinged by a nylon hinge or hinges 20 so that panel 18 can be folded back to lie beneath panel 17 in the direction indicated by the arrow X for the purpose of storage or transportation. All the internal valves and other components housed within the sections A, B, C, D, and E depend from the frames formed by components 2, 3, 11, 12 and 13. Accordingly, the top surface can be folded in the direction indicated by arrow Z about the hinges 6 and 7 located between sections D and C. Consequently, the bed can be folded for storage or transportation to take up approximately half its normal length use. Obviously before folding the bed for this purpose the air sacs are deflated and/or removed and manifold 21 which supplies and exhausts air from the bed is removed. Manifold 21 is connected to the end of the bed by a quick release catch 22 so that in the event of an emergency requiring administration of artificial respiration or heart massage to the patient, the air sacs can be rapidly deflated by simply removing the manifold and allowing the air sacs to exhaust through all the conduits and ports. The internal arrangement of the components of the bed is shown in Figures 2 and 4. As can be seen each section or group of bags is supplied by flexible hoses 24 from the manifold 21. The hoses 24 are flexible plastic tubes stiffened with a spirally wound plastic reinforcing rod enabling the bed to be folded without flattening the hoses. The arrangement of the hoses is shown in Figure 4 from which it will be seen that each group of sacs or bags is fed separately via an inlet 25 and each group of bags is exhausted through a compensator valve 26 whose construction and function is described in British Patent Specification No. 1601808. Raising or lowering of the head sections A and B is achieved using a head bellows 27 which operates in a similar manner as described in British Patent Specification No. 1474018. Air is supplied to the bellows 27 via a solenoid controlled actuating valve 29 whose construction is shown in Figure 4 of British Patent Application No. 2077859. In order to avoid undesired collapse of the head section by leakage of air from the bellows and its associated air supply conduits, a control valve 30 is provided which is located beneath the upper surface of the section B. Valve 30 consists of a micro switch operated solenoid valve, the opening and closing which is controlled by the micro switch. The air supply hose 24 from valve 29 is connected to bellows 27 through inlet via valve 30. The micro switch is activated by a lever 31 mounted on a pivot 32 and connected by a clutch to an arm 33. The end of arm 33 remote from the clutch abuts on the underside of the top surface of section B of the bed. A spring (not shown) is provided to press the abutment of arm 33 against the top panel of section B. The valve 30 is arranged so that with the bellows 27 fully inflated and the head section in the fully raised position, the solenoid valve 30 (which is a three-port valve) is in its exhaust mode and is exhausting air from the bellows. As the head section begins to fall the micro switch is operated causing valve 30 to switch to its inlet mode thereby diverting air into the bellows and closing the exhaust. This situation will continue until the bed reaches its top position again whereupon it starts to fall and the cycle is repeated. As a result, the head section is continuously maintained within a very short pivoting range. Although the arrangement described in Figures 1, 2, and 3 of British Patent Application No. 2077859 could alternatively be used to control the supply of air to the bellows and prevent undesired falling of the head section, the advantage of the valve described herein is that the valve is always in a fully open position so that the response is quicker. The foot section of the bed can be raised in a similar manner to that described in Figure 1 of British Patent Specification No. 1474018 by means of a foot bellows 35 controlled by a solenoid valve 36 mounted within section E of the bed. Valve 36 is similar to valve 29and both are operated remotely by a low voltage control wire or by other remote control systems such as radio or an infra red beam. The foot section can be raised by articulation between sections D and E and C and D, and a parallelogram linkage (not shown) may be provded to ensure that the section E is maintained in a plane approximately parallel to the base board 18 of the bed. The air supply to the bed is provided by flexible hoses to the manifold 21 from a control unit e.g. as indicated in Figure 6 of British Patent Specification No. 1474018. The support appliance described can be laid on top of a bed frame or divan base or supplied with its own under frame. It will be apparent that the support appliance described above could be modified in a number of ways. For example, the bellows 27 and 35 (and the associated valves, switches and linkages) are not essential for all intended uses of the appliance; and so a simplified and cheaper appliance could be made without incorporating these parts. In this case, however, the sections of at least one pair of adjacent sections should still be articulated together to permit the appliance to be folded for transportation.

Claims: Claims 1. A support appliance adapted to be supported on a bed frame and comprising a plurality of elongated inflatable air sacs, mounted in groups and extending transversely of the appliance so as to provide a surface for supporting a person thereon, the appliance comprising a series of connected box-shaped housings, each housing being associated with a group of air sacs and each comprising a pair of tubular longitudinal members, through which air is supplied to or exhausted from the sacs, and a panel joining the tubular members to provide a smooth, obstruction free surface, wherein the housings of at least one pair of adjacent housings are articulatedly joined together. 2. An appliance according to claim 1, further comprising means for supplying air to the tubular members, said means comprising flexible conduits passing through the housings from a manifold mounted at one end of the appliance. 3. An appliance according to claim 2, wherein the manifold is mounted on one end face of one of the terminal box-shaped housings by means of a quick-release latch, mechanism. 4. An appliance according to claim 2 or claim 3, wherein a compensator valve is located in each housing in the vicinity of a tubular member through which air is exhausted from the respective group of air sacs and arranged to maintain the rate of flow of air through the group of sacs within predetermined limits. 5. An appliance according to any one of the preceding claims, wherein the housings of each pair of adjacent housings are articulatedly joined together. 6. An appliance according to claim 5, wherein a bellows is housed within one or both of the terminal housings of the appliance, and flexible conduits are provided to conduct air thereto and actuate the bellows, the articulated joint between the or each terminal housing and the adjacent housing permitting the appliance to be contoured in response to operation of the bellows. 7. An appliance according to claim 6, wherein one of the terminal housings is constituted by two box-shaped housing sections rigidly connected together, each housing section being associated with a group of air sacs, and each comprising a pair of tubular longitudinal members. 8. An appliance according to any one of claims 5 to 7, wherein the flexible conduits for supplying air to the bellows are connected to control valves located within a box-shaped housing. 9. An appliance according to any one of the preceding claims wherein the box-shaped housings are open in a downward direction and are closed off by a common base board. 10. An appliance according to claim 9, wherein the base-board is formed in two or more hinged sections so as to be foldable on each other, the housings being pivotable in the opposite direction from the box board sections, so as to facilitate storage and transportation.

Inventors: HOWLING RICHARD JOHN, HUNT KENNETH WILLIAM, HUNT WILLIAM VALENTINE, HOWLING, RICHARD, JOHN, HUNT, KENNETH, WILLIAM, HUNT, WILLIAM, VALENTINE
Applicants: MEDISCUS PROD LTD, MEDISCUS PRODUCTS LIMITED
Application year: 1984
Main classification: A61G7
IPC codes: A47C27, A61G7