GB2184026A - Applicator for a compression bandage - Google Patents

Abstract

An applicator for a compression bandage (1) comprises tensioning means (5-13) through which the compression bandage is led within the applicator. The tension in the bandage leaving the applicator is thus set by the tensioning means. The tension in dispensed lengths of bandage can be adjustably set (e.g. by screw 57 in Figure 3). <IMAGE>

Description

SPECIFICATION Applicator for a Compression Bandage Technical Field This invention relates to an applicator for a compression bandage.

Prior Art Compression bandages are used in the treatment of venous disorders to apply pressure to a limb; preferably a pressure decreasing from the extremity of the limb towards the torso.

Compression bandages can be made from a wide range of fabric structures but all have one feature in common-they all show some degree of stretch and recovery.

The stretch property is obtained by using stretch yarns to manufacture the fabric of the bandage; either crepe yarns (with a high degree of twist), textured continuous filament yarns, or elastic yarns (made from an elastane or elastodiene).

The pressure obtained when a compression bandage is used depends markedly on the extension (and thus the tension) at which the bandage is applied and this is difficult to control.

Clinical studies have shown that a variation in pressure of three times can be found when the same type of bandage is applied by a group of nurses.

Even after special training, the variation was still two times. This makes it impossible for a physician to know exactly what treatment is actually being applied. In addition, it is generally agreed that graduated compression is desirable, reducing on a leg from the ankle upwards and it was difficult to obtain this with any degree of consistency when applying compression bandages by conventional manual procedures.

Now the pressure produced by a bandage is governed by the Laplace relation k#T P r where P is the pressure k is a constant T is the tension in the bandage, and r is the radius of curvature around which the bandage is applied.

The geometrv of the human leg is such that its radius of curvature increases from the ankle to the knee and thus a bandage applied to a leg at constant tension will give graduated compression decreasing from the extremity of the leg towards the top.

The present invention relates to an applicator which allows even an unskilled user to obtain and control the compression required when applying a compression bandage.

Summary of the Invention According to the invention, an applicator for a compression bandage comprises a mounting for a compression bandage and tensioning means through which a compression bandage can be led from the mounting and from which the compression bandage can be pulled under a tension determined bythetensioning means.

The applicator may include a housing for, or comprising, the mounting and the tensioning means. Preferably the housing is adapted to be held in the hand.

The tensioning means may comprise two sets of nip rollers through which the compression bandage can be pulled in sequence, at least one roller of the first set being in driving connection with at least one roller of the second set so that when a compression bandage is pulled through the two sets of nip rollers, the surface speed of the rollers of the first set is lower than the surface speed of the rollers of the second set thus extending the compression bandage and increasing the tension in it.

The tensioning means may, alternatively, comprise a single set of nip rollers at least one of which rollers has braking means associated with it.

Each set of nip rollers may comprise two rollers in nip relation, or three rollers two of which are in nip relation with the third.

In an alternative arrangement the tensioning means comprises a pressure element resiliently urged with a predetermined force towards a counter-pressure element and between which elements the compression bandage is guided so that, by increasing the tension in the compression bandage, the pressure between the two elements is reduced and the compression bandage is dispensed from the applicator under a tension dependent on said predetermined force.

Brief Description of the Drawings The invention will be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a section illustrating diagrammatically a first embodiment of applicator according to the invention, Figure 2 is a perspective view of the applicator of Figure 1 on a smaller scale, Figure 3 is a central, longitudinal section through a further embodiment of applicator according to the invention shown at twice actual size (see the 1 cm scale line).

Figure 4 is a section corresponding to that of Figure 3 through a part of the applicator of Figure 3 but on a reduced scale, Figure 5 is a view in the direction of the arrow V in Figure 4, and Figure 6 is a view, also on a reduced scale, in the direction of the arrow VI in Figure 3 with part of the applicator removed.

Description of Preferred Embodiments In the first embodiment to be described, shown in Figures 1 and 2, a loosely rolled bandage 1 is loosely located in a housing 4 in the applicator and threaded through two sets of nip rollers (5, 6, 7 and 8,9, 10) which ensure that no slippage of the bandage through these rollers can take place. The rollers 5 and 6 are in nip relation with one another as are the rollers 6 and 7. In the other set of rollers, the rollers 8 and 9 and the rollers 9 and 10 are in nip relation.

The two sets of rollers are drivably connected to each other by gears (11, 12, 13) such that the second set of rollers (8, 9, 10) must rotate at a faster speed than the first set (5, 6, 7), thus producing a fixed extension in the bandage when it is pulled through the roller system. This extension is governed by the gearing ratio and can be changed by a change of gears, to suit the particular load extension properties of the bandage used. In fact, as can be seen from Figure 1,the driving connection between the two sets of nip rollers relies on the gear wheel 11, mounted to rotate with the roller 7, the gear wheel 13, mounted to rotate with the roller 8 and the gearwheel 12 intermeshed with the gearwheels 11 and 13.Thus in this example, the driving connection is by gear wheel between one roller of each set and the remaining rollers are driven by frictional action as the compression bandage is pulled between them.

The actual tension in the bandage as it is pulled out of the applicator is not the same as that generated internally between the roller systems, but is less by a factor dependent on the gearing ratio.

Obviously friction in the bearings will also have an effect and this must be keptto a minimum.

The fact that the extension at which the bandage is applied is less than that to which it is stretched in the applicator is an advantage in that tension decay with time after application will thereby be reduced, compared with that existing if the bandage were to be applied without any retraction occurring from a greater degree of extension.

In use, the free end of the bandage is held onto the limb to be bandaged with one hand and the housing 4 is held in the other. As the housing 4 is pulled away from the end of the bandage held on the limb, the bandage will unroll and, by wrapping the bandage around the limb as it unrolls, will be applied at a consistent tension.

The housing 4 of the applicator is made in two parts 16 and 17 hinged together at 18. The rollers 5, 7, 8 and 10 are mounted in the part 16 whilst rollers 6 and 9 are mounted in part 17. The parts 16 and 17 are hinged open to allow the roll of bandage 1 to be placed inside the housing 4, which constitutes a mounting for the bandage. The free end 2 of the bandage 1 is laid across the rollers 5, 7, 8 and 10.

The housing 4 is then closed, and the rollers 6 and 9 form nips with rollers 5, and 7, 8 and 10 respectively to grip the bandage 1. The gears 11, 12 and 13 are such that the surface speed of roller 8 is greater than that of roller 7 by an amount such that a desired, predetermined tension is produced in the bandage as it is pulled from the applicator. The sets of rollers 5,6,7 and 8, 9, 10 thus constitute means for tensioning the bandage. In general, the surface speed difference of the sets of rollers can be a ratio between 1.2 and 3.0 depending on the loadelongation characteristics of the bandage.

The housing 4 is part-cylindrical and is of such a shape and size that it can be held comfortably in the hand.

Protuberances 20 and 21 inside the parts 16 and 17 respectively provide a narrow gap 19 between a chamber 22 in the housing 4 in which the bandage 1 is located and the region of the housing in which the nip rollers are located and thus ensure that the bandage unrolls easily and prevent the bandage roll coming into contact with the first set of nip rollers.

Figure 2 shows an overall view of the applicator of Figure 1.

In a second embodiment of applicator according to the invention, an alternative tensioning means for the compression bandage comprises one set of rollers at least one of which has associated with it an adjustable brake so that the tension of the bandage is directly controlled. In this case the brake must be calibrated in terms of the tension produced, normally between 0.2 and 2.0 kg force.

Such a system, using a braking means as a tensioning means, has a theoretical advantage in that it can be used with bandages whose loadelongation properties are variable but it is not easy to control the braking force accurately and reproducibly and it does not first stretch the bandage past its desired working extension and then allow it to retract. Tension decay after application is therefore greater than when using the first embodiment of applicator described with reference to Figures 1 and 2.

A third embodiment of applicator according to the invention is shown in Figures 3 to 6 of the accompanying drawings. This applicator comprises a housing 25 formed in two parts 26 and 27, which are connected together by a hinge 28. The part 26 of the housing 25 comprises a cover plate 29 with two side plates 30 and 31 secured to its by screws (not shown) and the part 27 of the housing 25 comprises a cover plate 32 with two side plates 33 and 34 secured to it by screws (also not shown). The housing 25 constitutes a mounting for a rolled compression bandage 37 (shown only in Figure 3) which is received in a space 38 within the housing 25.

At the end remote from the hinge 28, a block 39 extends between the side plates 30 and 31 of the housing part 26 and a block 40 extends between the side plates 33 and 34 of the housing part 27. The blocks 39 and 40 are secured by screws (not shown) to the cover plates 29 and 32 and their associated side plates respectively. The blocks 39 and 40 thus form a mouth opening 41 for the housing 25.

The parts 26 and 27 of the housing 25 are releasably secured to one another in Figure 1, in the region of the mouth opening 41, by two press fasteners comprising two pins 42 and 43 fixed in the block 39, one at each side of the mouth opening 41, and two studs 44 and 45 fixed in the block 40.

Secured to the part 27 of the housing 25 by screws (not shown) and extending at right angles to the adjacent section of the cover plate 32 is a partition wall 46 which divides the space 38 within the housing from a space containing tensioning means for the bandage 37, to be described below. The lower part 47 of the wall 46 extends into the part 26 of the housing 25 but is not secured to it. The lower part 47 of the wall 46 carries two guide pins 48 and 49 located adjacent the side plates 33 and 34 respectively at a spacing corresponding to the width of the bandage 37.

Rotatably mounted in the part 26 of the housing 25 so as to extend between the side plates 33 and 34 adjacent the guide pins 48 and 49 is a guide roller 50 so that the end of the bandage 37 can be led over the roller 50, between the guide pins 48 and 49 and into the tensioning means, now to be described.

The tensioning means comprises a counterpressure element constituted by a strip 53 of friction material, for example DYCEM (Trade Mark) non-slip material accommodated in a recess 54 in the lower part 47 of the wall 46 and extending across the whole width of that wall. The tensioning means further comprises a pressure element constituted by a hollow bar 55 urged towards the strip 53 with a predetermined force by a spring 56 located on a bolt 57. The bolt 57 has a screw-threaded head 58 engaged in a central screw-threaded aperture 59 in the block 39. The hollow bar 55 is carried on two pins 62 and 63 which are fixedly secured (e.g.

soldered or welded) in apertures in the hollow bar 55 and are mounted on pivot blocks 64 and 65 with spigots 66 and 67 loosely journalled in sockets 68 and 69 in the side plates 30 and 31 respectively. Stop pegs 76,77, fixed to the respective side plates 30, 31, extend into the ends of the bar 55 and limit movement of the bar 55 under the urging of the spring 56 when the housing 25 is opened (see Figure 4). The force with which the spring 56 urges the hollow bar 55 towards the strip 53 can be adjusted by rotating the bolt 57 in the aperture 59 via the accessible head 58.

The pins 62 and 63 project upwardly (in Figure 3) beyond the hollow bar 55 and serve, in use, as further guides for the bandage 37.

Between the blocks 39 and 40 in the mouth opening 41 of the applicator are mounted parallel, spaced-apart rollers 72 and 73 which extend across the mouth opening between the side plates 30, 31 and 33,34 respectively. These rollers 72 and 73 serve to guide the bandage 37 out of the applicator.

The bandage 37, mounted in the applicator by location within the space 38 within the housing 25, is led out of the space 38 over the roller 50, between the guide pins 48 and 49 and is then led between the strip 53 and the hollow bar 55 which, together with the associated elements, constitute the tensioning means for the bandage. The bandage then passes over part of the circumference of the hollow bar 55, between the pins 62 and 63 and leaves the applicator between the rollers 72 and 73. Threading of the bandage 37 is easily effected when the parts 26 and 27 of the housing 25 are pivoted apart by pulling the pins 42 and 43 away from their respective studs 44 and 45.

When the end of a bandage 37 is pulled away from the applicator in the direction of the arrow 74 in Figure 3, the bandage is initially gripped between the hollow bar 55 and the friction strip 53. As the pull on the bandage is increased, increasing the tension in the bandage, the pressure between the hollow bar 55 and the friction strip 53 is reduced allowing the bandage to be pulled out of the applicator.

In fact, the path along which the bandage 37 is guided is such that pulling on the bandage to increase the tension in it exerts a force on the hollow bar 55 urging it directly, or substantially directly away from the strip 53. If the tension in the bandage is allowed to fail below the force exerted by the spring 56, it will be gripped again between the hollow bar 55 and the strip 53 and prevented from leaving the applicator. The tension under which the bandage 37 is dispensed from the applicator is thus dependent on the predetermined force exerted by the spring 56 and, of course, this can be adjusted by turning the bolt 57.

Normally, the bandage 37 will be applied by holding the free end of the bandage on a limb and moving the applicator around the limb, but the tension under which the bandage is applied to the limb is still determined as described above.

The bandage in any of the above-described embodiments of the invention may be mounted on a cylindrical core roller 75 (shown dotted in Figure 3), releasably secured in the applicator. The mounting for the bandage will then be constituted by the roller 75 on which the bandage is carried.

Each of the two parts 26,27 of the housing 25 can be moulded from plastics material (e.g. by injection moulding).

Claims (10)

1. An applicator for a compression bandage, comprising a mounting for a compression bandage and tensioning means through which a compression bandage can be led from the mounting and from which the compression bandage can be pulled under a tension determined by the tensioning means.

2. An applicator as claimed in claim 1, wherein the tensioning means comprises two sets of nip rollers through which the compression bandage can be pulled in sequence, at least one roller of the first set being in driving connection with at least one roller of the second set so that when a compression bandage is pulled through the two sets of nip rollers, the surface speed of the rollers of the first set is lower than the surface speed of the rollers of the second set thus extending the compression bandage and increasing the tension in it.

3. An applicator as claimed in claim 1, wherein the tensioning means comprises a single set of nip rollers at least one of which rollers has braking means associated with it.

4. An applicator as claimed in claim 1, wherein the tensioning means comprises a pressure element resiliently urged with a predetermined force towards a counter-pressure element and between which elements the compression bandage is guided so that, by increasing the tension in the compression bandage, the pressure between the two elements is reduced and the compression bandage is dispensed from the applicator under a tension dependent on said predetermined force.

5. An applicator as claimed in claim 4, wherein the compression bandage is guided, after leaving the nip between the pressure element and the counterpressure element, over the pressure element and away from the counter-pressure element so that increasing tension in the compression bandage exerts a force on the pressure element urging it directly, or substantially directly, away from the counter-pressure element.

6. An applicator as claimed in any one of claims 1 to 5, wherein the said mounting for the compression bandage is a roller mounting.

7. An applicator as claimed in any one of claims 1 to 5, wherein the said mounting for the compression bandage comprises a housing in which the compression bandage is loosely located.

8. An applicator for a compression bandage substantially in accordance with any of the three embodiments hereinbefore described.

9. An applicator for a compression bandage substantially as hereinbefore described with reference to, and as illustrated in, Figures 1 and 2 of the accompanying drawings.

10. An appiicator for a compression bandage substantially as hereinbefore described with reference to, and as illustrated in, Figures 3 to 6 of the accompanying drawings.