GB2160425A

GB2160425A - Bandage for cold therapy

Info

Publication number: GB2160425A
Application number: GB08415778A
Authority: GB
Inventors: Wyndham Reginald Perring
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-06-20
Filing date: 1984-06-20
Publication date: 1985-12-24
Also published as: GB8415778D0

Abstract

A bandage for applying cold to an affected area is a fluid filled reservoir (1) formed from sheets of plastic laminate. The fluid stays as liquid or slush on cooling to below ???20 DEG C allowing the bandage to be stored in a refrigerator/freezer. A tie cord (11) and eyelet holes (9) are provided. <IMAGE>

Description

SPECIFICATION Bandage The present invention relates to a bandage for use in treating injuries. It is well known to treat some injuries, such as sprains, with a cold compress, a chill spray, or other cooling agent. Such treatments are also used for conditions such as migraine. Further, it is often desirable to keep a patient's head cool during an operation.

The present invention seeks to provide a bandage which may be applied with a cooling effect. Such a cooling bandage may provide a complete first-aid treatment for many common minor injuries and also be used in other conditions and situations requiring cooling treatment.

For convenience, the invention will hereinafter be described with reference to injured limbs, but this does not preclude the use of the bandage of the invention in other situations where cooling treatment is desirable.

The present invention provides a bandage comprising a reservoir defined by a flexible boundary layer, the reservoir containing a reservoir fluid which is not solid at 0 C, the flexible boundary layer being fluid-tight with respect to the reservoir fluid, and the bandage as a whole being sufficiently flexible that it may be bound around an injured limb.

Preferably the reservoir fluid is not solid at the operating temperature of the freezing compartment of a domestic refrigerator. For convenience it is most preferable that the reservoir fluid is not solid at temperatures at least as cold as -20 C, ideally several degrees lower, so as to be usable with the coldest domestic refrigerator freezing compartments and with domestic deep freezers which usually operate at -180Cto -20'C.

In use, the bandage should be kept in the freezer or freezing compartment, and only removed when needed to treat an injury. If the bandage is used in conjunction with a thermally insulated bag or holder, it may be kept in the freezer or freezing compartment normally but taken in the bag on any occasion when injuries are anticipated, e.g. by a coach or trainer attending an athletics meeting or a football match.

Preferably the reservoir fluid has a high heat capacity so that it keeps its low temperature for a long time when the bandage has been removed from the freezer.

It is desirable that the reservoir fluid should stay reasonably uniformly distributed over the area of the bandage when an injury is being treated, so as to cool the whole injured area. To this end the reservoir fluid is preferably thick and slow flowing. Suitably it may contain a gelling agent which provides it with a suitable viscosity at all operating temperatures.

A suitable reservoir fluid can be obtained by mixing glycerol, water, cellulosic thickener and one or more bacteriocides. A colouring agent may be added to improve the fluid's appearance if it is visible in the completed bandage. Examples of suitable formulations are: EXAMPLE 1 Parts by weight Glycerol BP grade 50.0 Water 50.0 Hydroxyethyl Cellulose of a grade which has a viscosity 2.0 of 480#6000 cp at 25 C, using spindle 4 of an LVF Brookfield at 60 RPM, at a concentration of 2% in water Ammonia solution of density 0.880 0.1 An antifoam agent known as Napco NXZ made 0.1 by Diamond Shamrock Ltd.

A biocide which is a blend of partially 0.5 chlorinated heterocyclic compounds EXAMPLE 2 Parts by weight Glycerol BP grade 50.0 Water 50.0 Apolyacrylatethickenerhaving a 1% solution viscosity of 6.0 1000-1500 poise on a Brookfield at 0.5 RPM. Viscosity as supplied being 5 cp with an SG of 1.05 and a solids content of 30% Ammonia solution of density 0.880 2.5 An antifoam agent known as Napco NXZ made 0.1 by Diamond Shamrock Ltd.

A biocide which is a blend of partially 0.5 chlorinated heterocyclic compounds Only two examples have been given. Many other thickeners may be used, e.g. alginates, polyacrylamides, modified starches, sodium polyacrylate etc. Advantageously the formulation is such that any air entrapped will be released, leaving a void free fluid. Although glycerol is the preferred "antifreeze" agent, other alcohols may be used, e.g. propylene glycol or hexylene glycol. Also an aqueous sodium chloride could be used (20% b.w. NaCI with 80% b.w. H2O is still a slush at -200C). The formulation can be varied to give desired viscosity etc. Preferably the fluid is a liquid or slush at -20 C.

Uniform distribution of the reservoir fluid can also be promoted by providing physical obstructions to its flow. For instance, these obstructions could be complete impediments to flow and divide the reservoir into a number of small separate reservoirs. Alternatively the obstructions may be a series of barriers each of which extends from one side of the reservoir most of the way to the other. They could be in a formation of two interlocking combs or in a herring-bone pattern, so that the (preferably thick) fluid has to follow a labarynthine path in order to flow along the bandage. Other barrier shapes are possible, and it is not necessary that all barriers extend to the side of the reservoir.

The boundary layer of the bandage is preferably a three layer laminate having the structure polyurethane-polyethylene-polyurethane. This layer may provide the outer surface of the bandage. In this case it is desirable to provide the outer side of the layer with a fine grain embossing so that it does not contact the skin smoothly. This helps to avoid giving freezer burns to the injured person. In practice a fish-scale embossing pattern having about 12 scales per cm has been found to be satisfactory. The use of an embossed outer side of the boundary layer as the bandage outer surface is advantageous in providing an efficient transmission of the cooling effect of the reservoir fluid to the injury being treated.

Alternatively the bandage may have an outer fabric cover. In this case there is no need for the outer side of the boundary layer to be embossed.

The dimensions of the bandage should be such as to allow it to be wrapped, and tied if necessary, around an injured limb. Various sizes and shapes could be used. A suitable example is a rectangular bandage about 50 cm long and about 15 cm wide. The reservoir could occupy substantially the whole of this area, the boundary around it being e.g. about 5 mm wide. This sized bandage could, for example, contain about 700 9~800 g of the fluid formulation given above.

The boundary layer is preferably made of two sheets of the laminate described above, forming the reservoir between them. The sheets may be bonded by any convenient method around the boundary of the reservoir and to provide any barriers as described above. This construction allows a simple fabrication process suitable for large scale production. The bonding may, for example, be by an adhesive, by heat sealing, or by high frequency welding.

The bandage may be tied in place when being used to treat an injury. This may be facilitated by providing one or more holes, not piercing the reservoir, through the bandage at one or both ends, through which hole or holes a cord (e.g. of polypropylene) may be passed. Alternatively one or more cords may be permanently bonded or otherwise fastened to the bandage.

It has been found that for best effect the pre-cooled bandage should be wrapped around the injury and left in place for at least 15 minutes. For severe injuries the pre-cooled bandage may be applied for 30 minute periods at 1 hour intervals for up to 24 hours. In the latter case the bandage should be returned to the freezer if possible between periods of application, so as to counter-act the warming up which it will suffer during the periods of application. The bandage of the present invention may be used alone or the injured limb may first be immobilised with a conventional bandage. The bandage should not, however, be used on open wounds.

An embodiment of the invention, given by way of example, will now be described with reference to the accompanying drawings, in which: Figure 1 is a plan view of a bandage embodying the present invention; Figure 2 is a side edge view of the bandage of Figure 1; Figure 3 is an end edge view of the bandage of Figure 1; and Figure 4 is a sectional view corresponding to a part of Figure 2 taken along the line A-A in Figure 1.

The bandage shown in the drawings has a fluid-filled reservoir 1 bounded by a boundary layer 3. The boundary layer is made of an upper sheet 3a and a lower sheet 3b of a polyurethane-polyethylenepolyurethane laminate as described above. The reservoir is closed by a heat-sealed boundary strip 5 around the edge of the bandage. The bandage is about 50 cm long and 15 cm wide, the boundary strip 5 is about 5 mm wide.

At each corner of the bandage there is a heat-sealed disc 7 through which a hole 9 has been made. A polypropylene cord 11 may be threaded through these holes to assist in fastening the bandage around an injured limb as described above.

The reservoir fluid is a thick fluid of high heat capacity, which remains fluid at temperatures at least as low as -20 C, for instance it may have one of the detailed compositions given above. There is about 700-800 g of this fluid in the reservoir 1. The reservoir may also contain a small amount of air.

In order to hinder movement of the fluid in the reservoir there are obstruction means in the form of partial barriers across the reservoir. These barriers are formed by heat sealing the boundary layer sheets 3a, 3b. Each barrier is a long thin sealed strip 13 extending from a boundary strip 5 more than half-way across the reservoir 1, and a sealed disc 15 at the end of the strip 13. The barriers are arranged in two interlocking comb-like arrays, one array extending from each side edge of the bandage. Thus if the reservoir fluid is to flow along the reservoir lit must follow a labarynthine path around the barriers. As the fluid is relatively viscous it does not easily flow along this path. Thus the barriers tend to promote a relatively uniform distribution of the fluid in the reservoir, as discussed above.

The outer side of both sheets 3a, 3b of the boundary layer 3 is embossed as discussed above, and as indicated by partial cross-hatching in Figure 1.

In use, the bandage is cooled by being kept in a e.g. the freezing compartment of a domestic refrigerator or a domestic deep freezer. When needed, it can be removed and wrapped around an injured portion of the body to provide a cooled bandage. It may be useful to provide a thermally insulated bag in which the pre-cooled bandage can be transported to an event where its likely need is anticipated.

The embossing on the outer surface of the bandage helps to avoid freezer burns from it. If the outer side of the boundary layer 3 does not form the outer surface of the bandage, e.g. the bandage has a fabric cover, then the embossing is not necessary and the outer side of the boundary layer 3 may be smooth.

Claims

1. A bandage comprising a reservoir defined by a flexible boundary layer, the reservoir containing a reservoir fluid which is not solid at OOC, the flexible boundary layer being fluid-tight with respect to the reservoir fluid, and the bandage as a whole being sufficiently flexible that it may be bound around a human limb.

2. A bandage according to claim 1 wherein the reservoir fluid is not solid at temperatures at least as cold as -20 C.

3. A bandage according to claim 1 or claim 2 wherein the boundary layer is a fluid-tight laminate of synthetic polymeric materials.

4. A bandage according to claim 3 wherein the boundary layer is formed from two sheets of laminated synthetic polymeric materials bonded together around the periphery of the reservoir.

5. A bandage according to claim 4 wherein the sheets are additional bonded together, within the said periphery, to define a labarynthine reservoir.

6. A bandage according to any one of the preceding claims wherein the outer surface of the boundary layer has an embossed pattern.

7. A bandage according to any one of the preceding claims wherein the reservoir fluid contains a gelling agent to increase the viscosity thereof.

8. A bandage according to any one of the preceding claims having one or more through holes, and/or a cord fastened to the bandage.

9. A bandage substantially as herein described with reference to the accompanying drawings.

10. In combination a bandage according to any one of the preceding claims, and a thermally insulating container therefor.