WO1997034553A1

WO1997034553A1 - Bandage

Info

Publication number: WO1997034553A1
Application number: PCT/GB1997/000784
Authority: WO
Inventors: Mitchell James Notaras
Original assignee: Mitchell James Notaras
Priority date: 1996-03-20
Filing date: 1997-03-20
Publication date: 1997-09-25
Also published as: GB9605863D0

Abstract

An elongate strip of an integral reticulated elastomeric polymer material, in which the mesh dimension thereof is substantially larger than the filaments, and which has surface protuberances, is appropriate for therapeutic use as a bandage by wrapping it around a body part so that layers thereof are superimposed and interlock without occlusion of the body.

Description

BANDAGE Field of the Invention

The invention relates to a new application of a non-woven integral elasticised sheet net material as a bandage.

Background of the Invention

Surgical dressings and plasters have been developed for the following purposes: 1. The protection of the healing wound. 2. The prevention of contamination of the environment with wound exudate which may contain bacteria.

3. The retention of a dressing or a medicament in contact with the surface of the body.

4. The restriction of movement of part of the body by traction or compression.

5. By maintaining compression, the prevention of accumulation of tissue fluid in a dependent part. There is no ideal product. Choice will be a compromise and will depend on an appreciation of the salient features of the anatomy and physiology or normal skin and the conditions to which it will be exposed.

Skin is normally infested with bacteria which present no problem to the host, provided that normal environment of the skin is maintained and the openings of the hair follicles and the ducts of the sweat glands are not occluded. Besides being permeable to the water lost by active sweating, the epidermis is permeable to water vapour and gases. In injuries where the epidermis is removed, the loss per unit area may increase tenfold. Under normal conditions, the surface temperature of the skin is less than body temperature. Occlusion of the surface of the skin not only prevents the evaporation of water vapour and a rise of surface temperature, but causes a quantitative increase in the bacterial flora. Bacteriological studies have shown that under a microporous water vapour-permeable dressing, the quantitative bacterial count is less than under occlusive dressings, and the incidence of recovery of pathogenic organisms is greatly reduced.

Wounds under dressings heal in artificial conditions. This is an important factor, when drawing conclusions about the effect of a dressing on healing. Studies of wound healing have raised substantial doubt regarding the biological desirability of the widespread practice of merely cleansing a small wound and exposing it to drying air without some type of cover. Present roll-on bandages, of the type that may be wrapped around a body part, may be divided into:

(a) Bandages made of various knitted fabrics such as cotton or synthetic materials. These bandages have minimal stretch. They are typically fixed with an adherent tape or safety pin or a supplied fixation device. An example is Kling marketed by Johnson & Johnson.

These bandages easily loosen with movement and often have to be reapplied. Multi-overlapping of even these porous bandages will greatly reduce, if not completely abolish, their porosity.

Many woven bandages can be stretched along their length but do not stretch sideways. These products are most commonly used to retain dressings in position or in the treatment of sprains to restrict movement, to limit oedema in dependent parts and to hold large dressings in position. They are commonly known as supporting bandages.

(b) Bandages made of various knitted fabrics which include an elastic component which allow the bandage to be applied with some compression or tightness, to conform and maintain pressure on the area, e.g. a limb. An example is Elastocrepe marketed by Smith & Nephew. They have the same disadvantages as for (a) .

(c) Elasticised knitted fabric bandages with an adhesive on one side. The adhesive material fixes to the skin and between layers. An example is Elastoplast marketed by Smith & Nephew. Again, their overlapping will greatly reduce, if not completely abolish, their porosity. Their unwinding is frequently difficult. Also, removal of the layer of bandage adherent to the skin is painful. The adhesive tends to perish with time, with a consequent loss of its adhesive properties. Some patients react to certain dressing adhesives, particularly when they are applied to regions of the body other than the hand.

Because of movement of the tissues, or when plasters or strapping are used to apply stresses to the body, for example orthopaedic strapping, the use of adhesive may cause considerable stresses and strains to develop at the adhesive/epidermal interface within the epidermis and at the epidermal/dermal junction, which may result in disruption of the tissues. Sweat glands and hair follicles may become occluded by the adhesive, and the evaporation of water vapour may be prevented.

Sometimes, in order to obtain adequate wound healing, the dressing must be changed often. Thus the repeated use of adhesive tape over the area of skin becomes a major factor in dressing changes. These tapes by nature are occlusive; that is they allow moisture to build up under them during wearing. This moisture over-hydrates and softens the outer layers of skin so that, when the tape is removed, these outer layers of skin are easily disrupted.

(d) Self-adherent wrap type bandages made of a crimped synthetic elastic material with a "bubbly" surface. When applied, they stretch. The nature of the surface of the bandage allows it to adhere together. An example is Coban marketed by 3M. When multi-layered, the porosity is abolished.

(e) Microporous tape made from a non-woven fibre with ' acrylic adhesives. Acrylic adhesive can be used repeatedly without causing trauma to the outer skin layers. There is permeability to liquid or water vapour only if applied as a single layer. However with overlapping, these advantages are lost. An example is Micropore tape marketed by 3M. This type of tape does not stretch and cannot be used for compression.

Accordingly, the overlapping of porous dressings, bandages, strapping and plasters, adversely affects their porosity. This is a considerable disadvantage, with marked pathological effects on the skin and on wound healing. Suπvmarv of the Invention

According to this invention, a bandage is made of an elastomeric net-like sheet material which by virtue of an increased friction coefficient does not slip when overlapped, with multi-layering. It may have means whereby it can interlock with itself, as it is overlapped on itself when wound around a part. This is achieved by increasing the thickness and altering the shape at the cross-over points. When layered on itself, the cross-over points will lock into the pores of the net/mesh.

Because of the elastic nature of a net mesh, it will stretch and will conform with the area bandaged and thus maintain the original bandaged position. Movement or sliding of the layered material over itself can be avoided. The non-slippage is increased by the interlocking component in the design. The bandage is thus particularly suitable for maintaining pressure, where desired. No adhesive is required. It is thus particularly suitable for medical use, although it may be used to wrap any object. Description of the Invention

The self-locking bandage is of a different design to (d) . The novel bandage is an integral elastopolymer mesh/net and, where the filaments intersect with each other (the junctures) , the intersections are thickened in various shapes by increasing the volume of the polymer, preferably but not necessarily at each junction or intersection in three dimensions, so that there is a marked nubbing of the intersections as a "knob" or "blob" or "hook" . When the elasticised bandage of the invention is stretched and applied (e.g. to a limb) , in multilayering or overlapping on itself the projections at the junctions of any one layer of the bandage interlock with both the adjacent inner and outer layers. The interlocking action combined with the high co-efficient of friction of the elastic polymer net material prevents the bandage from slipping and it thus maintains its conformity and pressure as required. The juncture points or "high spots" may be 5-10 times the thickness of the filaments and may be round, elliptical or squarish or any shape according to its method of manufacture, whether extrusion or moulding. The pores of the netting may be square, rectangular, round or any shape depending on the technique of manufacture. The elastomer net may stretch in any direction with stretching ratios of from 3/1 to 10/1.

As the bandage is tensed during its application this stretching increase the size of the pores. Despite multi-layering and overlapping, the holes in the net are of such a size that the skin is never completely occluded. Because it is a net-like material with large holes it allows perspiration and with cooling of the skin prevents overheating at the surface.

In material of the present invention, the mesh dimension is substantially larger than the filaments, so that the fabric has a high open area. For example, the mesh size may be 0.5 to 10, e.g. 1.5 to 5, mm, while the filament size may be 0.1 to 2.5 mm, for example 0.2 to 1.5 mm. This high ratio, e.g. of 1:1 to 25:1, means that, when layers of a strip of material according to the invention are superimposed after the strip is wrapped around a body part, the body is not occluded. This may assist healing, and permits washing.

In material of the invention, and as indicated above, protuberances allow superimposed layers to interlock. The protuberances may be provided on one or both faces of the material. If provided on one face only, the other face will usually be the body-contacting face. The protuberances will most conveniently be provided at the intersections of the filaments of the material, as has previously been proposed in order to provide increased strength at the intersections, although they may also be present elsewhere on the filaments. These protuberances do not need to be accurately proportioned to fit into the pores of the fabric.

The accompanying drawing shows a highly schematic partial plan view of material for use in the invention and also a schematic sectional view of the material when wrapped around on itself, e.g. over a wound (not shown) . This view may be considered as an expanded section, or in a state prior to tightening, when the layers are brought into closer contact. The protuberances are staggered in superimposed layers, so that they interlock with the open mesh in one or both adjacent layers. Another application of the elastomer netting as described comprises introducing a "filler" in the openings, e.g. an absorbent, air-permeable material. Such a material need not limit the elasticity or compromise the interlocking of the intersecting "knobs". For example, the openings of the net material may be filled with a cotton or synthetic wool type material, or paper material in a thin layer in such a way as to allow the expansile or stretching nature of the intersecting filaments. The elastic net bandage is able to incorporate a material for absorbency but remains compliant enough to allow the projecting junctions to enter the holes.

Claims

1. An elongate strip of an integral reticulated elastomeric polymer material, in which the mesh dimension thereof is substantially larger than the filaments, and which has surface protuberances, for therapeutic use as a bandage by wrapping it around a body part so that layers thereof are superimposed and interlock, without occlusion of the body.

2. A strip according to claim 1, in which the mesh size is 1.5 to 5 mm.

3. A strip according to claim 1 or claim 2, in which the filament thickness is 0.2 to 1.5 mm.

4. A strip according to any preceding claim, additionally comprising an air-permeable absorbent filler material.