GB2028121A

GB2028121A - Patient support means

Info

Publication number: GB2028121A
Application number: GB7928792A
Authority: GB
Original assignee: Cotton Silk and Man Made Fibres Research Association
Current assignee: Cotton Silk and Man Made Fibres Research Association
Priority date: 1978-08-18
Filing date: 1979-08-17
Publication date: 1980-03-05
Also published as: GB2028121B

Abstract

The patient support means is composed at least mainly of a mass of bonded fibres (10) either heterofil fibres or homofil fibres, or a mixture of both, of very low density and high porosity, whereby such means, at least in selected areas, has desirable load-bearing characteristics, namely is deformable to give a large increase in load-bearing area for a small deflecting force, both statically and dynamically. Such mass of bonded fibres may constitute the bottom layer of a mattress, there being a middle layer (12) of a similar mass of bonded fibres but having good bulk and serving as a buffer between the bottom layer (10) and a top layer (14) of still another similar mass of bonded fibres but comprising fine fibres to provide comfortable and medically-safe body contact. <IMAGE>

Description

SPECIFICATION Patient support means This invention concerns patient support means.

When a patient has to endure a long period in bed, serious problems can arise. In the main these problems concern the effects of pressure, especially on certain parts of the body, which interfere with circulation of blood and as a result cause decubitus ulcers (socalled bed sores) which are very distressing and very difficult to heal if the patient must remain bed-ridden. Numerous proposals have been put forward for solving such problems and indeed there are in use various forms of special bed equipment based on some of these proposals. Amongst these may be mentioned mattresses of foam material, mattresses containing water (usually referred to as waterbeds), and similar body supports containing granular materials.However, generally speaking, none of these proposals has been wholly satisfactory or successful, and for a variety of reasons, such as a tendency to inhibit normal movement or to give unpleasant sensations of abnormal movement; expense; and hygiene problems.

The object of the present invention is to provide inexpensive and hygienic patient support means which in use will be effective to prevent excessive pressure on the body of a user, especially on these parts of the body which are normally susceptible to bed sores (e.g. the shoulders and buttocks).

According to the present invention a body support means, for example for a bed-ridden person, comprises a mattress composed at least mainly of a mass of bonded fibres, either heterofil fibres or homofil fibres, or a mixture of both, of very low density and high porosity, whereby the mattress, at least in selected areas, is deformable to give a large increase in load-bearing area for a small deflecting force, both statically and dynamically.

The term "mattress" is to be understood as embracing not only simple flat structures but body support means in the form of seats alone, shaped pads to fit the back and seat portions of a chair, and the like.

Preferably the mass of bonded fibres will have beneath it means for accepting liquid which may drain therethrough, if necessary by way of special liquid drainage holes or paths.

Such means may be disposable, or form part of a continuous drainage system for the liquid. It will often be desirable for the characteristics of the mass of bonded fibres to vary through the thickness thereof or along the length thereof, or both, for purposes later to be described.

As to the nature of the fibres and the proportions thereof we may use a mixture of heterofil fibres and homofil fibres, e.g. consisting of from 25% to 75%, preferably from 40% to 60%, by weight of heterofil fibres (say 40%), and from 75% to 25%, preferably 60% to 40%, by weight of homofil fibres (say 60%). Any of the currently available types of heterofil fibres may be used and they will be preferably not more than 50 decitex (such fibres are readily and cheaply available in crimped form); and the homofil fibres will be not more than 250 decitex, though the higher part of this range is preferred. The thickness of the mass need be only a few inches.

Alternatively, we may use only heterofil fibres, or only homofil fibres, preferably not exceeding 250 decitex. The density of the mass of bonded fibres is very low indeed, the porosity being correspondingly very high, the actual volume of fibre preferably amounting to 5% or less of the total volume. However, whilst the mass is quite rigid enough to serve as a mattress, its surface deforms under the weight of a person lying thereon, especially at regions (such as under the heels and shoulders) where high pressures normally arise, to give quite substantial increases in the load-bearing area, and whether the person is still or moving. In this way the general comfort of the user is increased, and, in particular, bedsores are less likely to occur, and, if present, healing may well be encouraged.

The mattress just described is of a homogeneous nature and represents a very simple and unsophisticated embodiment of the present invention, if when in use it is placed on top of a conventional mattress (which may be protected for example by a water-proof sheet) or even directly on a hard base. However, the mattress described may be more satisfactorily employed in a composite arrangement consisting say, of a bed frame, a conventional mattress, a water-proof sheet, a disposable absorbent pad, the fibrous mass and, optionally, a sheet of stretch fabric. If desired, means could be provided to blow heated air into and through the mass of bonded fibres for warmth and to keep the patient dry if there is incontinence or wound exudate. Possible modifications to such an arrangement are many.Thus, instead of an absorbent pad, means may be provided to drain away urine or other liquid to a suitable collecting location. In its simplest form such means could be the previously mentioned water-proof sheet, disposed at a slight angle. Again, there may be provided, additionally, a readily deformable support immediately beneath the mass of bonded fibres.

Such a support could be in the form of a lattice-like structure of highly flexible material, or of an envelope containing suitable granular material, and would, it is believed, enable the thickness of the mass of bonded fibre to be reduced without effecting its essential characteristics. However, it may well be that a thicker mass of bonded fibre would be more convenient and economic since such masses as have been described can be produced very cheaply, and can be readily laundered. Indeed, it is likely that their cost could be low enough that they could be regarded as disposable after say 20 or so launderings. The conventional mattress is certainly not intended to be regarded as essential.

Perhaps the most important modification however, would be to vary the characteristics of the mass of bonded fibres, as has been previously mentioned, and the invention will now be described further, again only by way of example, with reference to other and detailed embodiments, illustrated in the accompanying drawings, in which: Figure 1 is a sectional side elevation of a mass of bonded fibres being, or being part of, a patient support means according to the present invention; Figure 2 is a sectional side elevation of a modified version of the mass of bonded fibres of Fig. 1; and Figure 3 shows, in side elevation to a reduced scale, the mass of bonded fibres of Fig. 1 as part of a patient support means for hospital use.

Referring firstly to Fig. 1 a mass of bonded fibres intended to serve as a mattress has three layers of different characteristics which will now be described, commencing with the bottom layer (percentages are by weight).

The bottom layer 10 is about 5 cms thick and consists of 60% polypropylene homofil fibres of from 100-250 decitex and 40% polyethylene-polypropylene heterofil fibres of the side-by-side type and of from 5-15 decitex. This layer has the desirable load bearing characteristics previously mentioned.

The middle layer 1 2 is about 1.25 cms thick and consists of 60% polypropylene homofil fibres of from 10-50 decitex and 40% polyethylene-polypropylene heterofil fibres of the side-by-side type of from 2-15 decitex. This layer has good bulk and serves as a "buffer" between the coarse lower layer and the fine upper layer now to be described.

The upper layer 14 is about 0.75 cms thick and consists of 40% by weight of polypropy lene homofil fibres of from 2-7 decitex and 60% by weight of polyethylene-polypropylene heterofil fibres of the side-by-side type of from 2-7 decitex. This layer is comfortable and medically safe to lie on, and indeed will normally not be covered by a sheet in use.

In all the layers just described a mixture of homofil and heterofil fibres is used. However, in any layer all homofil or all heterofil fibres may be used to obtain the load-bearing, buffer, or comfort characteristics referred to.

The use of a top sheet is in general, undesirable, since it can adversely affect the performance of the mattress and give rise to pressures at certain parts of the users' body which are significantly above the ideal maximum of 40 mm of mercury. A tightly-tucked in sheet can virtually eliminate any benefit so far as reduction of pressure is concerned, and a sheet if used should be preferably of highlystretchable fabric, and should be left as free as possible. The use of a sheet is also undesirable in cases of incontinence for obvious reasons.

Normally fibres of a given decitex within the quoted ranges will be selected.

If the middle layer is omitted, then the thickness of the upper layer is increased, say to 1.5 cms.

In one example of a mattress according to the invention in which the "buffer" layer 1 2 is omitted, the layer 10 consists wholly of 20 decitex polyethylene-polypropylene heterofil fibres and the layer 14 consists wholly of 3.3 decitex such fibres. In another example the layer 10 consists wholly of 1 7 decitex acrylic fibres (or 44 decitex modacrylic fibres having flame retardant properties) and the layer 1 4 consists wholly of 1.7 decitex acrylic fibres. In any event the fibres of the layer 10 will preferably not exceed 250 decitex and the fibres of the layer 1 4 will preferably not exceed 10 decitex.

It is to be understood that the omission of a "buffer layer" 1 2 is optional.

The mattress of Fig. 1 may be further refined (Fig. 2) to give a larger increase in load-bearing area for a given force in the regions of the shoulders, buttocks and heels, of a user, where the pressure normally tends to be higher than in the regions of the small of the back and the thighs and calves. This may be achieved by, for example, contouring a relatively hard base 16, on which the mattress lies, as shown, so that there is a greater depth of layer 10 beneath the regions of the shoulders, buttocks and heels of the user. A similar effect may be achieved by arranging that the interface between the two adjacent layers 12, 14 be similarly contoured so that there is a greater depth of softer fibre at the regions in question. Another technique which may be used in this connection is variation in fibre concentration as a means to obtain variable compressibility, and this technique may also be employed to obtain, say a bottom skin which is impervious and may be used for drainage purposes. Variation in fibre concentration may be achieved by heating certain parts of the fibre mass to a higher temperature than other parts such that there is some collapse of the fibre structure there. Needling may also be used to vary the fibre density or concentration.

In Fig. 3 the mattress 10, 12, 14 is shown lying on a base support 1 8 (which may be a conventional mattress) with an interposed catchment means 20 coupled by a conduit 22 to a drainage vessel 24. On top of the mattress a sheet 26 is shown, though this is preferably omitted. The whole assembly rests on a bed frame 28. A fan 30 may be pro vided for supplying warm air to the mattress 10, 12, 14.

The mattress, where heterofil fibres are used, is preferably produced in a mould press, oven, autoclave or the like by the application of the necessary heat to melt the lower melting point component of the heterofil fibres, followed by cooling, whereby bonding is effected in known manner. Steam heating is desirable since lower temperatures can be employed and oxidation of the fibres is avoided. Clearly, before the heat is applied, the various mixings of fibres, each as a carded or air laid mass of appropriate thickness, are laid one on top of the other. Fibre density may be varied by needling, which may also serve as a means of obtaining better locking together of the layers. In a modified process the layers are produced independently and then secured together by other means such as adhesive.

Where only homofil fibres are used, other suitable bonding methods are employed. For example in the case of acrylic or modacrylic fibres the use of a latent solvent (sulpholane) to obtain bonding in known manner, is preferred.

By virtue of the present invention, a mattress especially for hospital use, with several desirable qualities may be provided. First the incidence of bed sores is reduced; second, laundering is simple and quick; third, drainage of liquids may be coped with during use in a simple manner; and fourth aeration can readily be obtained for personal warmth and for evaporative purposes. The mattress is above all, cheap: so cheap that it may indeed be adapted for general hospital use, which would be very beneficial.

The use of reticulated structures formed of polymeric fibres with at least three pores per linear centrimetre to afford flame suppression in case of fire has been proposed. For example small spherical structures of this kind have been placed in aircraft fuel tanks. The structures can be made from bonded mixtures of heterofil and homofil fibres similar to those of the present invention. However, as is clear, the appreciation that bonded mixtures of that kind could be used to make mattresses in such a way as to provide the benefits of the present invention was not to be in any way deduced from the flame suppression work described.

Claims

1. A body support means for example, for a bed-ridden person, comprising a mattress composed at least mainly of a mass of bonded fibres, either heterofil fibres or homofil fibres, or a mixture of both, of very low density and high porosity, whereby the mattress at least in selected areas, is deformable to give a large increase in load bearing area for a small deflecting force, both statically and dynamically.

2. A body support means as claimed in Claim 1, in which disposed beneath said fibre mass, is means for accepting liquid which may drain through the latter.

3. A body support means as claimed in Claim 2, in which said means for accepting liquid is disposable.

4. A body support means as claimed in Claim 2, in which said means for accepting liquid is part of a continuous drainage system for the liquid.

5. A body support means as claimed in any one of claims 1 to 4, in which said fibre mass has liquid drainage holes or paths therethrough.

6. A support means as claimed in any one of claims 1 to 5, in which there are from 25% to 75% by weight of heterofil fibres and from 75% to 25% by weight of homofil fibres.

7. A body support means as claimed in claim 6, in which there are from 40% and 60% by weight of said heterofil fibres and from 60% to 40% by weight of said homofil fibres.

8. A body support means as claimed in claim 6 or 7, in which there are 40% by weight of heterofil fibres and 60% by weight of homofil fibres.

9. A body support means as claimed in any one of claims 1 to 5, in which the fibres are all heterofil fibres.

10. A body support means as claimed in any one of claims 1 to 5, in which the fibres are all homofil fibres.

11. A body support means as claimed in any of claims 1 to 8 in which a mixture of fibres is used, the decitex of the heterofil fibres is not more than 50.

1 2. A body support means as claimed in any one of claims 1 to 8, in which a mixture of fibres is used the decitex of the homofil fibres is not more than 250.

1 3. A body support means as claimed in claim 9 or 10, in which the decitex of the fibres is not more than 250.

1 4. A body support means as claimed in any one of the preceding claims in which the volume of fibres consists of 5% or less of the total volume of the mass.

1 5. A body support means as claimed in any one-of the preceding claims, in which the characteristics of said mass of bonded fibres vary through the thickness thereof or along the length thereof, or both.

1 6. A body support means as claimed in claim 15, in which a variation in characteristics through the thickness thereof is obtained by the addition of a top, substantially thinner, layer consisting of a second mass of bonded fibres, either heterofil fibres or homofil fibres, or a mixture of both and, as a whole, finer than those of the mass of bonded fibres which provides said desirable load bearing characteristics.

1 7. A body support means as claimed in claim 1 e, in which said second mass of bonded fibres consists of 40% by weight homofil fibres and 60% by weight heterofil fires.

a%. A body support means as claimed in claim , in which said second mass of bonded fibres consists of all heterofil fibres.

19. A body support means as claimed in claim 1 6 in which said second mass of bonded fibres consists of all homofil fibres.

20. A body support means as claimed in any one of claims 1 6 to 1 9 in which the decitex of the fibres of said second mass of bonded fibres is not more than 10.

21. A body support means as claimed in any one of claim 1 5 to 20 in which a further variation in characteristics through the thickness thereof is obtained by the addition of an intermediate, substantially thinner, layer consisting of a further mass of bonded fibres either heterofil fibres or homofil fibres, or a mixture of both, and having substantial bulk so as to act as a buffer beneath said top layer.

22. A body support means as claimed in claim 21 in which said further mass of bonded fibres consists of 60% by weight of homofil fibres and 40% by weight heterofil fibres.

23. A body support means as claimed in claim 21 in which said further mass of bonded fibres consists of all heterofil fibres.

24. A body support means as claimed in claim 21 in which said further mass of bonded fibres consists of all homofil fibres.

25. A body support means as claimed in any one of claims 21 to 24 in which the decitex of the fibres of said further mass of bonded fibres is not more than 50.

26. A body support means as claimed in any one of claims 1 5 to 25 in which a variation in characteristics along the length thereof is obtained by varying the thickness of the fibre mass or one or both additional layers, or both along its length.

27. A body support substantially as hereinbefore described with reference to and as illustrated in Figs. 1 or 2 of the accompanying drawings.

28. A patient support means for hospital use, and incorporating a body support means as claimed in any one of the preceding claims, substantially as hereinbefore described with reference to and as illustrated in Fig. 3 of the accompanying drawings.