GB2490709A

GB2490709A - Self-contained splint using frangible fluid pouch

Info

Publication number: GB2490709A
Application number: GB1107845.8A
Authority: GB
Inventors: Mary Anne Cordeiro; Nicholas Charles Stacey; Christoher Creasey; Michael Roger Cane; Andrew Troup; Jeremy Peter Clements
Original assignee: FLEXYCAST Ltd
Current assignee: FLEXYCAST Ltd
Priority date: 2011-05-11
Filing date: 2011-05-11
Publication date: 2012-11-14
Also published as: GB201107845D0

Abstract

The invention relates to a self-contained splinting system which may be used for immobilising limb injuries in an emergency setting. The self contained splinting system comprises: a pair of sheets 1 of fluid-proof material sealed to define an enclosure, within which is at least one layer of casting material 4 which sets on contact with a fluid; and at least one sealed pouch 5 of the fluid able to be in fluid communication with the enclosure, and openable from outside the enclosure. The waterproof pouch 5 may be within the enclosure and rupturable on application of pressure to the pouch from outside, for example at a seam or seal edge. A layer of wicking material 2 may help to distribute the fluid, along with an irrigation system 9. A further material with an exothermic reaction may accelerate setting of the casting material. The casting material 4 may be plaster of Paris or polyurethane resin, and the fluid may be water. A method and kit is also provided.

Description

I

Medical device

FIELD OF THE INVENTION

This invention relates to a self-contained splinting system which may be used, for example, for immobilising limb injuries in an emergency setting.

BACKGROUND TO THE INVENTION

An injured limb should be immobilised at the scene of an accident, prior to transporting the patient to the point of care to minimise pain, further injury and co-morbidity.

Currently, a number of techniques are used by civilian paramedics, each of which is recognised to have limitations. In one approach a "box splint" is employed, which essentially composes of a U-shaped channel. In reality, limbs are not box shaped and there is poor conformability with limb contours. Furthermore, injured limbs are often deformed or angulated. Flexible splint rolls (e.g. SAM® splints) constitute a foam covered pliable metal sheet which is conformed to the limb before being wrapped with a crepe bandage. Whilst versatile and lightweight, these splints are most appropriate for small limbs, have poor conformability and require considerable manipulation of the injured limb. A better system, is a so-called vacuum splint. Broadly speaking this comprises a bag of soft beads which wraps around the limb and which, when evacuated using a vacuum pump, becomes rigid. This works well but is relatively bulky to carry and requires a vacuum pump. Importantly, because each of these splints is relatively expensive and bulky they are reused, causing infection control problems (they are typically one of the few non-disposable items for patient use in an ambulance). Further, because they are left on the patients in the accident and emergency department, the ambulance is then left without a full supply of splints.

There is therefore a need for improved approaches in particular (but not exclusively) for a versatile and effective limb splint for emergency or pie-hospital use. It is particularly desirable that an improved device be self-contained (an important feature for emergency use), simple to appy, conformable, cheap and disposable.

SUMMARY OF THE INVENTION

According to the present invention there is therefore provided a self-contained splinting system, the system comprising: a pair of sheets of fluid-proof or impermeable material, sealed to define an enclosure; at least one layer of casting material within said enclosure, said casting material setting on contact with a fluid; and at least one sealed pouch of said fluid in fluid communication with said enclosure, and openable from outside said enclosure to allow said fluid to contact said casting material to set said splinting system.

Embodiments of the splinting system are inexpensive and disposable and easy to conform to a limb in its broken position. The system may be configured as a flat pack, allowing many to be stored easily on an ambulance. In embodiments the splinting system may be sterile and stored within suitable outer packaging. Because the system is self-contained and has its own fluid supply, for example water, it is easy to use at say, the scene of an accident.

In some preferred embodiments the fluid is a liquid, in particular water. Thus in embodiments the fluid-proof material is a liquid-proof material, more particularly a waterproof material. However the fluid may alternatively comprise a gas, when the pack is vacuumised. For example the pouch may contain water which may at least parlially become water vapour on opening the internal water pouch, the reduced pressure assisting dispersion of the water vapour to the casting material. More generally, arranging for the enclosure to be at less than atmospheric pressure (1 OOkPa) can assist dispersion of the fluid.

The casting material may be any suitable material which transforms from a flexible form to a rigid form on contact with the fluid. However in some preferred embodiments the casting material comprises a polyurethane resin or plaster-of-paris impregnated into a support material, and the fluid comprises water. In other embodiments, however, other fast acting resin systems and hardeners may be employed.

In other embodiments the fluid comprises vapour, more particularly water vapour in air, may be employed as an activation mechanism. Air may be employed in conjunction with, for example a mesh impregnated with a cyanoacrylate material, which may be maintained in an un-polymerised form by a vacuum. Then breaking a seal can enable polymerisation and setting.

It is helpful to be able to control the setting time of the casting material -a setting time of less than 10 minutes is helpful, but if the casting material sets too quickly ease of use may be adversely affected. In embodiments the enclosure includes a material which has an exothermic reaction with the fluid, to accelerate setting of the casting material. One such material which may be employed is calcium chloride, which has an exothermic reaction with water. The amount of calcium chloride can be varied to control the setting speed. Additionally or alternatively a controlled proportion of catalyst or inhibitor may be incorporated into the casting material, the amount determined by routine experiment in order to control the rate of setting. In embodilments the acceleration material may be provided in a layer or sheet adjacent to the casting material, but this is not essential and other distributions of material may also be effective. For example calcium chloride powder may be distributed throughout the enclosure. Optionally, though less preferably, electrical heating means, for example wires, may be incorporated into the enclosure to allow controllable electrical heating, for example from an external power source.

Preferred embodiments of the splinting system also include one or more layers of wicking material, in particular located against the one or more layers of casting material. The wicking layer is important when the fluid is a liquid, helping to distribute the liquid evenly over the casting material, to ensure the water is in close proximity to the casting material, thus minimising the quantity of fluid required in the enclosure.

Embodiments of the splinting system comprise at least two layers of the casting material and at least two layers of the wicking material. In such an arrangement it is preferable to locate the wicking layers outside the layers of casting material (that is between the casting material and one of the outer waterproof sheets) to facilitate the layers of casting material adhering to one another to maximise mechanical strength. In such an arrangement the liquid is preferably delivered between the layers of casting material; in general the liquid is able to pass through the casting material and hence disperse within the enclosure. In embodiments a layer of casting material may comprise orthopaedic casting tape. It has been found that non-woven hydrophilic fibrous cloth provides a particularly effective wicking material.

In some embodiments it is beneficial to include a stiffening material, in particular a layer comprising a conformable but plastically deforming material, such as a set of wires or a sheet of deformable wire mesh in the laminate structure. This material may be located, for example, between the outer wicking layer and the outer waterproof material, although other locations are also suitable. This material can be easily conformed to the shape required, to hold the splint in the chosen shape whilst the casting material sets and provides the full splint rigidity.

In some preferred embodiments the sealed pouch of fluid is contained within the enclosure, but this is not essential. For example one or more pouches may be located outside the enclosure and/or part or all of one or more of the sheets of waterproof material forming the enclosure may comprise part of the pouch or pouches holding the fluid. In other arrangements the enclosure may be internally partitioned to define one or more pouches. Where a pouch is located outside the enclosure, it may be connected to the interior of the enclosure via a tube or other fluid conducting means.

In some preferred embodiments the sealed pouch has a breakable or frangible seal such that under application of (manual) pressure to the pouch, in embodiments from outside the enclosure, the seal breaks to allow the fluid to contact the casting material.

Such pressure may be applied either directly or indirectly and may optionally involve a twisting motion applied to the pouch. Alternatively, however, a tap, valve, removable clip or other manually or automatically openable closure may be provided to control egress of the fluid from the pouch.

In embodiments a pouch comprises a pair of layers of waterproof material, preferably a material with a low MVTR (moisture vapour transmission rate) such as a metal foil, (for example aluminium) metallised plastic film, low MVTR polymer film or films formed by laminating a combination of these materials. A metal foil laminate material is preferable for a long shelf life (greater than one year). The sheets of waterproof material defining the enclosure may be of similar material.

In embodiments the pouch layers are sealed around the edge, for example by adhesive or welding means, and the breakable seal is formed by a reduced strength region of this seal, for example a region in which the lateral width of the seal is reduced, or its geometry makes it weaker or produces a higher stress in this area, or the bond adhesion strength is reduced. Additionauy or alternatively where the sealing is performed using a high temperature heat sealing process, the frangible region can be fabricated by employing a lower temperature at this region. However such approaches can be hard to control in practice and a preferable alternative is to form an inwardly pointing "V" at a portion of the perimeter of the seal. This forms a high stress point at which the seal can controllably fracture or peel open.

In some preferred embodiments the pouch is arranged to include a fold or gusset at its base in the manner of a self-supporting pouch, for example a Doypack (registered trade mark), such that when the pouch is full the pouch has three faces, and such that the fold or gusset can fold substantially flat when the pouch is empty. In this way a significantly enhanced volume of fluid can be contained within the pouch (a pouch may have a volume of for example 1 OmI to I ODmI). This has the additional advantage that it is easier to apply a higher pressure to break the seal. In embodiments the pouch(es) may be arranged to provide an excess of fluid over that needed to set the casting material, to ensure substantially complete wetting and thus activation to set.

In embodiments the fluid outlet from a pouch may include a diffuser to improve the diffusion of the fluid over the casting material. This is optional but may comprise, for example, a pattern or grid of obstructions to the fluid (liquid) flow. Although the diffuser may be a separate component; in some preferred embodiments it can be conveniently and cost-effectively formed by locally joining the pouch layers in an exit path for the liquid from the frangible seal; for example by means of a pattern of spot welds between the two pouch layers. Alternatively a diffuser may be formed in a similar way by locally joining other layers of material within the splinting system. Optionally a surfactant may be included in the fluid (liquid) to aid diffusion.

Additionally or alternatively an irrigation system may be coupled to the fluid exit of a pouch to distribute the fluid over the casting material. This may comprise; for example, a conduit provided with a series of holes along its length. This may be a separate component made of very thin plastic (not dissimilar to a plastic bag) or it may be integrally formed between or against one or more layers of the overall structure.

In an ideal embodiment one pouch will be sufficient to activate the casting tape; this is preferably located in the longitudinal centre of the splinting system. In alternative embodiments two or more pouches are located to provide the best irrigation of the splinting system, In a preferred embodiment a greater thickness of casting material is provided along a line, than to either side of the line and these may be aligned with a limb to be supported. It is advantageous if this also corresponds to a line between the two pouches. This corresponds with the fluid flow direction, and also provides a line of maximum strength which may be aligned with a limb to be supported. With such an arrangement the casting material will tend to set along the line between the pouches first, and this is also helpful. In embodiments a thickness of the casting material, for example a number of layers of casting tape, reduces towards an edge of the enclosure/splint. The seals of the pouches are preferably directed inwards towards the (lateral) centre of the enclosure/splint. In embodiments providing, for example, five or six layers of casting material along a centre line of a splint and only, say, one or two layers towards the edges of the splint makes it easier to conform the splint to a limb and, later, to remove the splint.

In some embodiments the splinting system also includes one or more adjustable fastening bands, for example of hook-and-loop material or adhesive tape, to enable the splint to be fastened around a limb whilst it sets, and afterwards checked (to ensure the limb is still perfused) and/or adjusted -as an injured limb often swells. This is particularly helpful in a version of the splinting system used for limb (backslab) splinting where emergency transport of the patient is necessary.

Limb injuries are often associated with lacerations and around 4% of fractures are topen' and it can therefore be advantageous to provide one or more layers of anti-microbial material on one or both outer faces of the enclosure. Furthermore this material can provide a fleece or gauze layer to improve comfort and provide thermal insulation from the splint and absorb bodily fluids. This is also helpful for other potential applications of the splinting system, for example in theatre after a nailing or plating procedure.

In a preferred embodiment the splinting system provides a backslab: Backslabs are the gold standard of treatment used by orthopaedic surgeons for acute fractures in the hospital setting. "Slabs" of casting material are applied to the posterior aspect of injured limb by specialist plaster technicians in a multi-step process using numerous components. These incomplete "casts" allow excellent comformity to the limb, maximising immobilisation, ease of application and allow for swelling of tissues.

Embodiments of the splinting system we describe enable use of this gold standard of care in the pre-hospital environment.

In embodiments the self-contained splinting system is packed in outer packaging which can maintain the splinting system in a low humidity and sterile environment to provide for a long shelf life. This outer package should preferably be impermeable to microbes and have a low MVTR and also be very quick to open. This could include aluminium foil based heat sealable laminates.

In embodiments the splint may have a tapered shape to allow an increased width portion of the splint to wrap around the wider proximal part of a limb.

Although a particularly convenient implementation of the splinting system integrally incorporates the pouch into the splinting system, some of the benefits of the invention can be obtained by providing a sealed container of the fluid as a separate item in combination with the waterproof enclosure portion of the splinting system. Thus the invention also provides a self-contained splinting system kit comprising these components. Where the sealed container of fluid is provided separately, the enclosure may be provided with one or more openable apertures for the fluid.

In a related aspect there is therefore provided a method of providing a self-contained splinting system, the method comprising: providing a pair of sheets of waterproof material, sealed to define an enclosure; providing at least one layer of casting material within said enclosure, said casting material setting on contact with a fluid; and providing an openable sealed container of said fluid together with said closure and casting material.

Preferably, but not essentially, the fluid is provided in a pouch with a breakable or frangible seal, advantageously located within the enclosure. As previously mentioned, in some preferred embodiments the enclosure is vacuumised at less than atmospheric pressure (100 kPa).

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will now be further described, by way of example only, with reference to the accompanying figures in which: Figure 1 shows an exploded view of a self-contained splinting system according to an embodiment of the invention; Figure 2 shows a plan view of a self-contained splinting system according to an embodiment of the invention; Figure 3 shows the system of Figures 1 and 2 in use; Figure 4 shows the outer foil bag; and Figure 5 shows an embodiment of the inner pouch containing water.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to Figure 1, this shows the layers used in one embodiment of a self-contained splinting system 100. The exact order of the layers may be changed to be optimised for different applications.

Layer I comprises an outer waterproof or impermeable material to prevent any liquid escaping. The wicking material is shown as layer 2. This is intended to distribute any liquids used e.g. water throughout the system to aid setting.

The accelerator 3 is a material distributed in the splint such as Calcium Chloride or other catalyst or inhibitor that is able to control the rate of setting. Calcium Chloride has an exothermic reaction with water, which heats the water to improve the reaction with the casting tape, which sets faster with increasing temperature.

The casting material 4 may be layered in a way to optimise its strength and flexibility when cured and this will depend on the limb and or type of injury being splinted. Any limb, for example an arm or leg, and potentially other areas of the body. may be splinted.

The fluid pouch(es) 5 are such that they can be opened by hand from outside of the fluid proof outer layer and their contents start the setting process.

A deformable wire mesh 6 is included to allow the splint to conform to the required shape instantly and to have enough residual stiffness to hold the splint in place whilst it sets.

Multiple fastening bands 7 are provided to hold the splint in place whilst it sets and to allow quick removal.

Figure 2 shows the layout in plan view used in one embodiment of the system (with the top layers and accelerator not shown).

The outer lower impermeable layer I also shows the edge 8 which will bond the upper and lower outer layers. In one embodiment the waterproof layers are glued together using hot glue to seal the various splint layers, but other methods of gluing, heat sealing and the like, known to the skilled person, may alternatively be employed.

The lower wicking layer 2 is shown above the deforniable mesh 6. Above these layers are the layers of casting material 4. The fluid pouches 5 are shown with an optional irrigation system 9. This comprises a tube with small holes or branches spaced along its length. The spacing of these holes is optimised for best irrigation. Example outer fastening bands 7 are shown, but the position and number of these will vary depending on the type of splint required. These may be loose bands or attached to the splint Figure 3 shows the splint around a lower arm and elbow. This shows the outer waterproof membrane I and the straps 7. Also visible is a felt, fleece or gauze layer 10 which forms a liner to the splint to provide comfort and thermal insulation, Figure 4 shows the splint in its outer packaging 101 which in this embodiment is made with a low MVTR foil laminate material. This can be easily opened using the tear points 102 and is heat sealed around the edges 103 and 104.

Figure 5 shows an embodiment of a fluid pouch 5, in this example a water filled D0yTM pack. This has a heat sealed edge 502 and folded base 503. The V shaped notch is shown 504 in which the tip 505 is the first point to break when the pouch is compressed.

No doubt many other effective alternatives will occur to the skilled person. It will be understood that the invention is not limited to the described embodiments and encompasses modifications apparent to those skilled in the art lying within the spirit and scope of the claims appended hereto.

Claims

CLAIMS: 1. A self-contained splinting system, the system comprising: a pair of sheets of fluid-proof material, sealed to define an enclosure; at least one layer of casting material within said enclosure, said casting material setting on contact with a fluid; and at least one sealed pouch of said fluid in fluid communication with said enclosure, and openable from outside said enclosure to allow said fluid to contact said casting material to set said splinting system.
2. A splinting system as claimed in claim 1 wherein said sealed pouch is within said enclosure.
3. A splinting system as claimed in claim 1 or 2 wherein said sealed pouch has a breakable seat such that under application of pressure to said pouch from outside said enclosure said seal is breakable to allow said fluid to contact said casting material to set said splinting system.
4. A splinting system as claimed in claim 3 wherein said pouch comprises a pair of pouch layers of fluid-proof material sealed around the edge, and wherein said breakable seal comprises a reduced strength region of said seal.
5. A splinting system as claimed in claim 3 or 4 wherein said pouch comprises a pair of pouch layers of fluid-proof material seated around the edge, and wherein said breakable seal comprises an inwardly directed 4V' shaped portion of said seal.
6. A splinting system as claimed in any preceding claim further comprising at least one layer of wicking material adjacent said layer of casting material.
7. A splinting system as claimed in claim 6 comprising at least two layers of said casting material, between at least two layers of said wicking material one adjacent each said layer of casting material, and wherein said at least one pouch of fluid is located between said layers of casting material.
8. A splinting system as claimed in any preceding claim wherein said pouch further comprises a diffuser to direct said fluid in a fan away from an exit region for said fluid.
9. A splinting system as claimed in claim 8 wherein said pouch comprises a pair of pouch layers of fluid-proof material sealed around the edge, and wherein said diffuser comprises a pattern of local joining of said pouch layers adjacent said exit region for said fluid.
10. A splinting system as claimed in any preceding claim further comprising an irrigation system coupled to a fluid exit region of said pouch to distribute said fluid over said casting material.
11. A splinting system as claimed in any preceding claim wherein a said pouch includes a fold or gusset such that when furl said pouch has three faces, and wherein said fold or gusset is configured to fold substantially flat when said pouch is empty.
12. A splinting system as claimed in any preceding claim wherein a thickness of said casting material reduces towards an edge of said enclosure.
13. A splinting system as claimed in any preceding claim comprising a plurality of said pouches disposed at edges of said enclosure, and wherein said pouches have frangible seals directed inwardly, away from said edges of said enclosure.
14. A splinting system as claimed in claim 13 wherein said splinting system has a greater thickness of said casting material along a straight line between two said pouches than to either side of said line.
15. A splinting system as claimed in any preceding claim wherein said enclosure is under less than atmospheric pressure.
16. A splinting system as claimed in any preceding claim wherein said enclosure further comprises a material which has an exothermic reaction with said fluid to accelerate setting of said casting material.
17. A splinting system as claimed in any preceding claim including one or more antimicrobial layers on one or more exterior surfaces of said enclosure.
18. A splinting system as claimed in any preceding claim further comprising one or more adjustable fastening bands to enable the splinting system to be adjustably fastened to a patient.
19. A splinting system as claimed in any preceding claim wherein said casting material comprises polyurethane resin or plaster of Paris impregnated into a support material and wherein said fluid comprises water.
20. A splinting system as claimed in any preceding claim wherein the system further comprises a layer comprising a conformable, plastically deforming material within said enclosure.
21. A self-contained sprinting system kit comprising an enclosure containing casting material, as recited in any preceding claim, in combination with an openable sealed container of said fluid.
22. A method of providing a self-contained splinting system, the method comprising: providing a pair of sheets of fluid-proof material, sealed to define an enclosure; providing at least one layer of casting material within said enclosure, said casting material setting on contact with a fluid; and providing an openable sealed container of said fluid together with said enclosure and casting material.
23. A method as claimed in claim 22 further comprising providing said fluid in a pouch with a breakable seal.
24. A method as claimed in claim 23 further comprising providing said pouch, within said enclosure, such that under application of pressure to said pouch from outside said enclosure said seal breaks to allow said fluid to contact said casting material to set said splinting system.
25. A method as claimed in claim 22, 23, or 24 further comprising controlling a rate of setting of said casting material by using a material which reacts with said fluid to vary a degree of acceleration of said setting.
26. A method as claimed in any one of claims 22 to 25 further comprising reducing a pressure within said enclosure to less than atmospheric pressure.
27. A system, kit or method as recited in any preceding claim wherein said fluid-proof material is a waterproof material.