GB2077580A - Body support - Google Patents

Abstract

A body support such as a bed, operating table or seat has a flexible top sheet 25 secured over the sides and ends of a frame, and resting on a series of parallel resiliently deformable rollers 21 located between the sides of the frame and supported, in turn, by a longitudinally reciprocating substantially horizontal bearer plate 18, which is driven back and forth causing the rollers to roll back and forth under the top sheet, thus constantly changing the main pressure areas of the body supported by the top sheet. <IMAGE>

Description

SPECIFICATION A body support THIS INVENTION relates to a body support, and more particularly to a bed, operating table, vehicle seat or other structure of a like or analogous nature on which a person may have to lie or sit for a consid erabletimewith little movement.

Hospital patients, confined to bed for long periods and incapable of, or restrained from, much movement, suffer great discomfort and may require frequent treatment to prevent, or treat, bed-sores resulting principally from restricted blood circulation at high pressure areas. Prolonged surgical operating procedures are also likely to result in impaired blood circulation of patients immobilised on operating tables, resulting in thrombosis, often with very serious consequences. Car and truck drivers, and aeroplane pilots, are likely to suffer considerable discomfort when required to remain seated with little movement for long periods, again due to local restriction of blood circulation.

The present invention has been devised to overcome or greatly minimise these effects of prolonged and unrelieved localised pressures on the body by providing a body support, such as a bed, or an operating table, or a vehicle seat, which is of such novel and improved construction as to promote rather than impair blood circulation and relieve localised pressures on the body of a user of the support.

Accordingly, the invention resides broadly in a body support such as a bed, operating table or vehicle seat, including a base frame, a substantially horizontal bearer member mounted on the base frame for reciprocal movement longitudinally with respect to the base frame, a series of parallel resiliently deformable rollers arranged transversely on, and supported by, the bearer member, a flexible top sheet secured on the base frame over and in contact with the rollers, and means for reciprocating the bearer memberto cause the rollers to roll back and forth in unison between it and the top sheet. Other features of the invention will become apparent from the following description.

In the drawings: FIG. 1 is a partly broken-away perspective view of a hospital bed according to the invention, FIG. 2 is a partly broken-away side view of the bed shown in FIG. 1, FIG. 3 is a partly broken-away plan view, to larger scale, of the reciprocating mechanism of the bed shown in FIGS. 1 and 2, FIG. 4 is a perspective view of a body support according to the invention applied to an operating table shown in broken outline, and FIG. 5 is a longitudinal sectional view of the body support shown in FIG. 4.

Referring initially to FIGS. 1,2 and 3 of the drawings, a body support unit, indicated generally at 10, is supported by a conventional hospital bed head 11 and foot 12. The unit includes a pair of parallel side members 13 with downturned end pieces 14 rigidly interconnected by cross-members 15. A pair of parallel bars 16, below the side members 13, are fixed between the cross-members 15, and a pair of flanged wheels 17 are rotatable mounted on each of the bars 16.

A horizontal rectangular reciprocating plate 18 is mounted on a pair of parallel rails 19 interconnected by cross-members (not shown), the rails 19 being supported on the two pairs of wheels 17. Side guards 20 depending from the sides of the plate 18 cover the wheels and rails.

Anumberofsimilarresiliently deformabletrans- verse rollers 21, each preferably of foam plastics material on a metal axle 22, are supported by the reciprocating plate 18 and located between a pair of elongated side plates 23, the ends of the axles of the two rollers 21 nearest to the head and foot of the bed being rotatable in bearing holes near the ends of the side plates, the axles of the other rollers having their ends engaged rotatable and in vertically movable manner in slots 24 extending down from the tops of these side plates.

A cover sheet 25 of pliable material such as a tough fabric is tensioned over and in contact with the rollers 21, having one end fixed about a rod 26 releasably held across the head of the unit 10 and its other end drawn down over a transverse rod 27 at the foot of the uhit 10 and fixed about a rod 28, the ends of which are engaged by a pair of elastic cords 29 leading to hooks 30 releasably engaged with a transverse bar 31 of the bed foot 12.

The reciprocating plate 18 is slowly reciprocated by a hydraulic mechanism indicated generally at 32.

It includes a double-acting hydraulic cylinder 33 fixed to the cross member 15 at the head of the unit, its piston 34 being connected to a pair of resilient pads 35 at front and back of a transverse member 36 secured between a pair of lugs 37 extending down from the two rails 19 under the reciprocating plate 18. Water under pressure, for example from a domestic water supply, is connected through a reversing valve 38 to one end or the other of the cylinder 33. The valve is of well known spool type mounted on a stem 39 slidableto either of two positions for directing the water under pressure to either end of the cylinder 33. The stem 39 is connected to a coaxial rod 40 which is slidable through a hole in the transverse member 36, and which is also slidable through a pair of annular magnets 41 and interposed spacer 42 which are fixed in a casing 43.A pair of iron discs 44 are secured on the rod 40, within the casing 43, and when one of the discs 44 is held to one magnet 41, the other disc is spaced from the other magnet. A pair of tubular stops 45 are slidable on the rod 40 to opposite sides of the transverse member 36 and a helical compression spring 46 is interposed between each stop 45 and a collar 47 adjustably secured on the rod 40. As the cylinder piston 34 nears the end of its stroke in either direction, the transverse member 36 is brought to one of the stops 45 and, with continued movement, com presses the spring 46 of that stop until the magnetic attraction of a magnet 41 to a disc 44 is overcome, whereupon the rod 40 is moved quickly to bring the other disc 44 to the other magnet 41.As the rod 40 makes these movements in one direction orthe other, it moves the valve stem 39 correspondingly to reverse the flow of water to the hydraulic cylinder 33.

The length of the stroke of the piston 34 may be adjusted by means of the collars 47, and its free quency may be controlled by adjusting the rate of flow of the water.

As the reciprocating plate 18 is moved back and forth, the resilient rollers 21 are rolled between the plate and the cover sheet 25.

A light overlay mattress 48 is normally placed on the cover sheet 25 and a patient lying on it, as indicated in broken outline in FIG. 2, will cause rollers 21 to be compressed to different extents to conform with the body contours. Since each of the roller axles is free to move vertically independently of all of the others, the roller as a whole, and not only that part above its axle, may be pressed down towards the reciprocating plate 18.

As the reciprocating plate 18 is slowly moved back and forth, the pressure between any part of the patient's body and the bed is alternately decreased and increased, and discomfort caused by prolonged pressure on parts of the body is thus greatly reduced. Moreover the alternating increase and decrease of pressure promotes a flow of air through the mattress 48, reducing the build-up of moisture, and the alternating compression and expansion of the rollers 21 assists in dissipating moisture from them.

If any of the rollers 21 between those at the head and the foot of the bed should become soiled, it can be quickly and easily removed and replaced by raising the cover sheet over the roller and lifting the roller from the unit and inserting a fresh one. If it is desired that pressure on any particular part of the patient's body should be kept as low as possible, an appropriate roller may be temporarily removed from the unit The use of the hydraulic apparatus for reciprocating the plate 18, and the valve operating mechanism employed, will ensure very quite operation and little vibration. If desired, the very small vibration caused by the operation of the valve may be further minimised by the addition of a dash-pot device on the valve stem 39 to cushion the final part of the stroke of the valve in either direction.

Referring now to FIGS. 4 and 5 of the drawings, a body support unit 50 is applied to an otherwise conventional hospital operating table indicated in broken outline at 51. The body support unit is installed in substitution for the part of the operating table which normally supports the legs of a patient, and it includes two parallel upright sides 52 rigidly interconnected by a rectangular base plate 53 and an end piece 54.

Above and parallel to the base plate 53 is a reciprocating plate 55, supported by a series of parallel transverse bottom rollers 56, which are rotatably mounted between a pair of parallel side bars 57, and are free to roll on the base plate 53 and against the underside of the reciprocating plate 55. The two bottom rollers 56a nearest two the end piece 54 have their middle parts reduced in diameter.

The reciprocating plate 55 is reciprocated by an electric motor 58 acting through a reducing gearbox 59 and a sprocket and chain drive 60 to drive a shaft carrying at its upper end a crank 61, a connecting rod 62 being pivoted at one end to the crank, passing closely under the nearer end of the reciprocating plate 55 and over the reduced-diameter middle parts of the rollers 56a, and pivoted at its other end to the reciprocating plate at 63.

A series of transverse resilient rollers 64 as before described are supported in spaced parallel arrangement on the reciprocating plate, their axles 66 being engaged in a pair of parallel side plates 67, those of the two end rollers being rotatable in round holes 68 in the side plates, those of the other rollers being engaged in vertical slots 69 from the tops of the side plates.

A cover sheet 70 of any suitable fairly heavy fabric material is fitted over the tops ofthe rollers 64, its sides and an end being brought down over the upper parts of the side 52 and end piece 54 of the unit and releasably held by press fasteners 71.

When a patient is on the operating table, the motor 58 is operated to move the reciprocating plate 55 back and forth, travelling easily on the bottom rollers 56, and the resiliently compressible rollers 64 are rolled back and forth in unison between the reciprocating plate 55 and the cover sheet 70. The legs of the patient, then, are subjected to a massaging effect stimulating the flow of blood through the vascular system and, it is believed, minimising the likelihood of thrombosis.

Claims (8)

1. A body support including: a base frame, a substantially horizontal reciprocating member mounted on the base frame for reciprocal movement longitudinally with respect to the base frame, a series of parallel resiliently deformable rollers arranged transversely on, and supported by, the reciprocating member, a pliable cover sheet secured on the base frame over and in contact with the rollers, and means for reciprocating the reciprocating member to cause the rollers to roll back and forth in unison between it and the cover sheet.

2. A body support according to Claim 1 wherein: the resiliently deformable rollers have axles interconnected by a pair of side plates in such manner that each may be depressed towards the reciprocating member independently of the others.

3. A body support according to Claim 2 wherein: the axles of the resiliently deformable rollers are removably engaged rotatably in bearings in the side plates and the intermediate rollers are removably engaged rotatably in substantially vertical slots in the side plates.

4. A body support according to any one of the preceding claims wherein the means for reciprocating the reciprocating member includes: a double-acting hydraulic cylinder connected to the base frame, its piston connected to the reciprocating member, a control valve connected in the circuit of the hydraulic cylinder and movable to either of two alternative positions to reverse the stroke of the piston, magnetic means for releasably retaining the valve in each of its two alternative positions, actuating means operatively connected to the said piston for moving the valve, when the piston nears the end of its stroke in either direction, from one of its positions, againstthe action of the magnetic means, to its other alternative position.

5 A body support according to Claim 4 wherein: the valve is slidably movable to its alternative positions by a:stertl, the magnetic means includes a pair of iron members connected to the movable stem to opposite sides of a fixed magnet, and the actuating means includes a pair of stops each acted on, through spring-loading means, by the piston as it approaches the end of its stroke in either direction.

6. A body support according to any one of the preceding claims wherein: the reciprocating member is mounted on a series of interconnected parallel transverse rollers movable on a substantially horizontal base plate on the base frame.

7. A body support substantially as herein described with reference to FIGS. 1,2 and 3 of the accompanying drawings.

8. A body support substantially as herein described with reference to FIGS. 4 and 5 of the accompanying drawings.