GB2438365A

GB2438365A - Prophylactic device

Info

Publication number: GB2438365A
Application number: GB0610425A
Authority: GB
Inventors: Victoria Jowett
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-05-25
Filing date: 2006-05-25
Publication date: 2007-11-28
Also published as: GB0610425D0

Abstract

This invention relates to a prophylactic device 100 for thrombo-embolic disease, the device comprising an elastic structure formed of contiguous first 102 and second 104 tubular members, said second tubular member being set at an angle to the first tubular member to define, at least in use, a generally L-shaped cavity configured to accept and fit closely about at least part of the foot and leg of a user; wherein said elastic structure is configured to apply a compressive force to at least part of said foot and leg, and the device further comprises a flexible and waterproof sole 106 affixed to at least part of a region of the elastic structure that overlies a plantar aspect of the user's foot in use.

Description

1 2438365 A Prophylactic Device This invention relates to prophylactic

devices. A preferred embodiment of the present invention relates to a prophylactic device for thrombo-embolic disease, such as might occur following a deep vein thrombosis (known generally as "DVT").

DVT can occur when venous blood flow velocity drops to a point where a thrombus (i.e. a blockage such as a blood clot) forms in an individual's vein. Once developed, parts of the thrombus (known as emboli) can break away from the thrombus and travel on through the circulatory system before lodging elsewhere in the individual's body where they can cause potentially fatal conditions such as a pulmonary embolism or an embolic stroke.

The incidence of DVT has been noted to increase substantially in situations where the individual is inactive for prolonged periods of time, such as might occur when an individual is travelling long distances in an aircraft or recuperating in hospital. In the case of air travel, the likelihood of DVT incidence can be further increased by relatively cramped conditions on board the aircraft, as well as the reduced pressure and humidity of the aircraft's ambient environment.

A variety of different devices have previously been proposed for helping reduce the likelihood of DVT occurring. For example, long-haul aircraft passengers and post-surgical, reclining or bed-confined patients are now commonly recommended to wear compression or anti-embolism stockings (such stockings also being known as TED (Thrombo-Embolic Deterrent) stockings). Compression stockings and TED stockings are elastic structures that are configured to exert a relatively high compressive force on (at least) an individual's foot and lower leg. The stockings function to increase venous blood flow velocity and thus reduce the incidence of deep vein thrombosis (DVT) and its frequent sequel, pulmonary embolism. To further reduce the incidence of DVT it is also now commonplace for long-haul airline passengers and hospital patients to be encouraged to undertake exercises which promote the maintenance of good circulation within their extremities, particularly their feet and legs.

For airline passengers, such exercises are best performed without footwear. However, as some passengers prefer to wear footwear when moving around the cabin of the aircraft (or indeed when walking between the aircraft and the airport) they can end up repeatedly putting on and taking off their footwear in the course of a flight. This can be highly inconvenient given the confines of many airline seats.

Hospital patients, in particular post-operative patients, can also find it difficult to put on and take off footwear when moving between their beds and other parts of the hospital. In addition, as hospital floors are typically not carpeted, they can be cold to walk on in only a pair of stockings, and also can present a dangerous slip hazard.

The present invention has been devised with the aim of addressing such problems, and to this end a presently preferred embodiment of the present invention provides a prophylactic device for thrombo-embolic disease, the device comprising an elastic structure formed of contiguous first and second tubular members, said second tubular member being set at an angle to the first tubular member to define, at least in use, a generally L-shaped cavity configured to accept and fit closely about at least part of the foot and leg of a user, wherein said elastic structure is configured to apply a compressive force to at least part of said foot and leg; and the device further comprises a flexible and waterproof sole affixed to at least part of a region of the elastic structure that overlies a plantar aspect of the user's foot in use.

The advantage of this arrangement is that a user need no longer repeatedly put on and take off their footwear in the course of a flight, or to move between their bed and other parts of a hospital. Rather, with the prophylactic device herein described the user is provided with the protection against embolism offered by such devices as well as the convenience of their normal footwear.

At this juncture it is worthwhile noting that the term "elastic structure" refers merely to a device that provides a compressive force to at least part of a user's foot and leg. One example of such an elastic structure is a compression stocking. Another example is the aforementioned thrombo-embolic deterrent stocking.

The compressive force exerted by the elastic structure on the foot and leg of the user may be substantially constant. Alternatively, the device may be configured to exert different compressive forces on the foot and leg of the user. In a particularly preferred arrangement the compressive force exerted by the device on the foot and leg of a user may increase from a proximal end thereof to a distal end thereof.

Preferably, the compressive force exerted by the elastic structure is at least 10mm HG, more preferably, at least 12mm HG. The compressive force exerted by the elastic structure may be between 10 to 25mm HG, and preferably between 12 and 20mm HG.

In one embodiment the first portion of the device may sized so as to terminate, at said proximal end, in the region of the user's knee. In another embodiment, the first portion may terminate in the region of the user's thigh. In yet another embodiment the device may be configured as part of a pair of tights, one or more legs of which comprise a prophylactic device as described herein.

The sole may be configured to cover substantially all of the portion of the elastic structure which overlies the plantar aspect of the user's foot in use. Alternatively, the sole may be configured to cover only part of the portion of the elastic structure which overlies the plantar aspect of the user's foot in use. The sole may extend towards a portion of the elastic structure which overlies the dorsal aspect of the user's foot in use.

The sole portion may be of rubber, plastics, silicone or any like material(s), or a combination of these. In one arrangement, the sole may be of latex rubber or polyurethane.

Preferably, the elastic structure comprises surface decoration. This arrangement is particularly desirable as commonly available compression stockings and TED stockings are not attractive articles, and as such there is a dangerous predilection amongst the fashion conscious to avoid wearing them.

The sole may be permanently affixed to the elastic structure. The sole may be adhered, sewn or fixed in any other way (for example by means of suitable fixings) to the elastic structure. The prophylactic device may include an insole provided inside the second tubular member, and the sole may be affixed through the elastic structure to the insole. In another arrangement the insole may be affixed through the elastic structure to a fixing layer provided on the outside of the elastic structure, and the sole may be adhered or otherwise affixed to said fixing layer. The fixing layer may be of rubber, such as Neoprene , for example.

In another arrangement, the sole may be formed directly onto the elastic structure so as to be an integral component thereof.

According to a another aspect of the present invention there is provided a method of making a prophylactic device for thrombo-embolic disease, the method comprising providing an elastic structure formed of contiguous first and second tubular members, said second tubular member being set at an angle to the first tubular member to define, at least in use, a generally L-shaped cavity configured to accept and fit closely about at least part of the foot and leg of a user, wherein said elastic structure is configured to apply a compressive force to at least part of said foot and leg; and affixing a flexible and waterproof sole to at least part of a region of the elastic structure that overlies a plantar aspect of the user's foot in use.

The method may further comprise providing an insole inside said second tubular member, and said affixing step may comprise affixing said sole to said insole through said elastic structure.

Preferred embodiments of the present invention will now be described, by way of illustrative example, with reference to the accompanying drawings, in which: Fig. la is a schematic rear perspective view of a prophylactic device in use; Fig. lb is a schematic side perspective view of the device of Fig. 1; Fig. ic is a schematic front perspective view of the device of Fig. 1; Fig. 2 is a schematic view of the underside of first illustrative sole of a device as depicted in any of Figs. la to ic; and Fig. 3 is a schematic view of the underside a second illustrative sole of a device as depicted in any of Figs. la to lc.

Referring to Figs. la, lb and ic there is depicted a prophylactic device 100 according to a preferred embodiment of the present invention.

The device comprises an elastic structure formed of contiguous first and second tubular portions, and En most instances the second tubular portion will have been integrally formed with the first. The first and second tubular portions are set at an angle to one another to provide, at least in use, a generally L-shaped internal cavity which is sized to accept and fit closely about the foot and leg of a user. As shown, the first tubular portion 102 is configured and arranged to accommodate the lower leg of a user and the second tubular portion 104 is configured and arranged to accommodate the foot of a user.

The elastic structure may be of a woven elastic one-way stretch construction. By this we mean that the elastic structure may be woven from individual elastic fibres such that it may only stretch in an outward direction to increase the cross-sectional area of the L-shaped cavity, and not in a direction which would increase the length of the device. The elastic structure could alternatively be designed so that it exhibits a greater potential for stretching in a direction which would increase the cross-sectional area of the L-shaped cavity, than in a direction which would increase the length of the device.

The first and second tubular portions exert a compressive force on the leg and foot of the user. In the preferred arrangement the elastic structure exerts a force of at least 10 mm HG, preferably at least 12 mm HG, and more preferably still a force between 10 and 25 mm HG on the foot and leg of the user.

The first and second tubular portions may be configured to exert substantially the same compressive force on the foot and leg of the user.

Alternatively, different regions of the device may be configured to exert different compressive forces on the foot and leg of the user. In a particularly preferred arrangement the compressive force increases in a direction from the leg towards the foot of the user so that the velocity of blood flow increases with distance from the user's heart to thereby provide a pumping effect that assists blood flow to and from the foot. The compressive force exerted by the device may also be varied to treat other conditions such as the effects and symptoms of venous insufficiency, for example varicose veins.

As shown in Figs. la and lb. the second tubular portion 104 has a sole 106 affixed to that part of the elastic structure which covers the plantar aspect of the user's foot (i.e. the sole of the user's foot) in use. In this instance the sole is of latex rubber and has a number of protrusions 108 which will later be described in detail with reference to Fig. 2.

In general the sole portion may be of rubber, plastics, silicone or any like material(s), or a combination of these. In one arrangement, the sole may be of polyurethane. In a preferred arrangement the sole may be configured so as to be relatively durable, and may be manufactured of a material that withstands washing (for example in a washing machine) so as to permit the user to clean the device after use.

The sole depicted in Figs. la to ic covers the entire underside of the device, but it will be appreciated by those persons skilled in the art that it need not be configured in this way. Rather if, as will later be described, the device includes a relatively stiff insole which is sufficient to withstand the weight of a user bearing on it without excessive flexing (by which we mean flexing to such a degree that the elastic structure comes into contact with the ground), then the sole may comprise a ring or rings of suitable material or indeed two or more separate components fixed at appropriate locations to that part of the elastic structure which covers the plantar aspect of the user's foot.

In this embodiment the first tubular portion 102 covers the user's lower leg and calf 112 and terminates in the vicinity of the user's knee 114.

In another embodiment the first tubular portion may continue above the user's knee to terminate in the region of the user's thigh. In another embodiment, the device may be configured as a pair of tights and one or more of the legs of those tights may be configured as a prophylactic device as herein described which exerts a compressive force on the user's leg and foot.

In a highly preferred embodiment a distal end of the device (generally in the vicinity of the user's toes in use) includes a retractable flap 118 in that part of the device which generally overlies the user's toes in use. This arrangement is particularly advantageous as access may then be had via the flap to the toes of the user to check that the user's circulation has not been compromised. The flap 118 extends across the width of the device and is shown in figure lb in an open configuration and in figure ic in a closed configuration.

The flap 118 may be provided on its underside with any type of releasable fastener so that it can be fastened to or detached from the remainder of the device. For example, the flap and the device may be provided with respective complementary parts of a mechanical hook and loop engagement device (such as Velcro ). As an alternative, buttons or press studs may be employed to allow the flap to be fastened to the remainder of the device.

In a highly preferred arrangement, the sole 106 is provided with a peripheral lip (not shown) so that the sole extends upward to cover at least a peripheral edge portion of that part of the device which covers the dorsal aspect of the user's foot in use. The elastic structure may also be provided with decoration 110 (such as embroidery) so as to enhance the aesthetic appeal of the device.

Fig. 2 shows in more detail the configuration of the underside of the sole 106 of the device depicted in Figs. la to lc. The sole of this embodiment is formed of polyurethane and is flexible and waterproof.

Toward a toe region 204 of the sole 106 are a number of raised protrusions 206 extending across the width of the sole 106. The protrusions 206 assist in cushioning, grip and flexibility. On a heel portion 208 of the sole 106 is a further raised protrusion 210, which provides increased grip and cushioning to a user, in use. In this particular embodiment, the sole 106 is about 5mm in thickness, and the protrusions 206, 210 project by about 3mm from the sole. It will be appreciated, however, that the projections may be larger or smaller, and further that the different projections may be differently sized.

For example, the aforementioned heel protrusion 210 may be significantly larger than the other projections provided on the sole so as to mimic the heel of a conventional shoe.

Referring now to Fig. 3, there is a shown the underside of another sole 302 for a device as herein described. In this embodiment, the sole 302 is formed from latex rubber and as a consequence is both flexible and waterproof. Towards a toe region 304 of the sole 302 are a number of grooves 306 which extend laterally across substantially the entire width of the underside of the sole 302. The grooves 306 are provided to further enhance the flexibility of the sole in the vicinity of the toes of a user, in use.

In this embodiment the sole 302 is also provided (generally in a position corresponding to the position of the user's instep in use) with a raised portion 308 that is shaped to at least generally correspond to (and hence support) the arch of the user's foot. A heel section 310 is situated at an opposite end of the sole 302 to the toe section 304 and comprises a region of thicker material which increases the degree of cushioning provided by the sole, particularly in the heel strike phase of the user's gait.

As with the embodiment depicted in Figs. la to ic and 2, the sole 302 may include a peripheral lip (not shown) that extends generally perpendicularly from a peripheral edge of the sole 302 and in use upwards toward an upper side of the users foot to cover at least a peripheral edge portion of that part of the device which covers the dorsal aspect of the user's foot in use.

A number of different manufacturing methods may be employed for the manufacture of a prophylactic device as herein described.

If the sole is of rubber (such as silicone or latex) or other like material, then the sole may be formed directly onto the elastic structure. In this instance, the elastic structure is first stretched over a generally foot-shaped anvil so that the second tubular portion generally assumes the shape of a human foot. Once the elastic structure is properly located on the anvil, the material from which the sole is to be formed is applied to the elastic structure whilst in a fluid form. The fluid material permeates into and bonds with the fibres of the elastic structure, and once cured the finished device can be removed from the mandrel.

Alternatively, if the sole is preformed (i.e. not formed directly onto the elastic structure) from a water resistant, flexible material (such as latex rubber, polyurethane or silicone) then the elastic structure may be stretched over an anvil as aforementioned, following which the preformed sole may be adhered or otherwise affixed (for example by stitching) to that portion of the second tubular member that will overlie the plantar aspect of the user's foot in use.

In a modification of this method, the device may include an insole that is located within the second tubular portion, following which the sole is affixed, for example by stitching, through the elastic structure (and any additional layers between the elastic structure and the sole) to the insole.

In a particularly preferred arrangement that portion of the second tubular member that will overlie the planter aspect of the user's foot in use may have a layer of rubber (such as Neoprene , for example) applied to an interior and an exterior surface thereof. Once the rubber layers have been attached to one another through the sock, for example by stitching, the flexible, water resistant sole may be adhered to the exterior rubber layer by means of any one of a multitude of commercially available contact adhesives. For this particular method, it is preferred for the two rubber layers rubber to be in the region of 4mm in thickness each.

As will be appreciated, the provision of rubber layers provides a significant cushioning to the user's foot in use, and to enhance this comfort level yet further it is envisaged that the rubber layers may conform to the contours of a user foot, either at the time of use or alternatively be preformed to match the contours of a particular user's foot. Similar considerations apply to the insole mentioned above.

It is clear from the foregoing the prophylactic device described herein provides numerous advantages over traditional compression or TED stockings. Furthermore, the provision of a flap is particularly advantageous as such an arrangement allows the circulation of a user to be continuously monitored.

It will be appreciated, but should nevertheless be noted, that whilst several embodiments have been described above in detail, those descriptions are purely illustrative and as such are not to be considered as limiting the scope of the present invention. It is also the case that many modifications and alterations may be made to the particular embodiments herein described without departing from the scope of the invention as hereafter claimed.

For example, whilst several materials have been mentioned above as being preferred, it should not be taken that this list of materials is exclusive.

Rather, persons skilled in the art will immediately appreciate that a large number of alternative materials may alternatively be employed. Similarly, whilst one particular embodiment of the invention discloses the concept of providing a flap by means of which the toes of a user may be accessed, it will be appreciated that the flap may be omitted (for example so that the device is "open-toed"), and that other apertures (closable or permanent) may be provided in the device at appropriate locations for monitoring the circulation of the user.

Claims

Claims 1. A prophylactic device for thrombo-embolic disease, the device

comprising an elastic structure formed of contiguous first and second tubular members, said second tubular member being set at an angle to the first tubular member to define, at least in use, a generally L-shaped cavity configured to accept and fit closely about at least part of the foot and leg of a user; wherein said elastic structure is configured to apply a compressive force to at least part of said foot and leg, and the device further comprises a flexible and waterproof sole affixed to at least part of a region of the elastic structure that overlies a plantar aspect of the user's foot in use.

2. A prophylactic device according to Claim 1 wherein said elastic structure comprises a compression stocking or a thrombo-embolic deterrent stocking.

3. A prophylactic device according to Claim 1 or 2, wherein the compressive force exerted by the elastic structure on the foot and leg of the user is substantially constant.

4. A prophylactic device according to Claim 1 or 2, wherein the elastic structure is configured to exert different compressive forces on the foot and leg of the user.

5. A prophylactic device according to Claim 4, wherein the compressive force exerted by the device on the foot and leg of a user increases from a proximal end of the device towards a distal end thereof.

6. A prophylactic device according to any preceding Claim wherein the compressive force exerted by the elastic structure is at least 10mm HG, preferably at least 12mm HG.

7. A prophylactic device according to any preceding claim, wherein the compressive force exerted by the elastic structure is between 10 to 25mm HG, preferably between 12 and 20mm HG.

8. A prophylactic device according to any preceding claim, wherein the the sole is configured to cover substantially all of that portion of the elastic structure which overlies the plantar aspect of the user's foot in use.

9. A prophylactic device according to any of Claims 1 to 7, wherein the sole is configured to cover only part of the portion of the elastic structure which overlies the plantar aspect of the user's foot in use.

10. A prophylactic device according to any preceding claim, wherein the sole is extended towards a portion of the elastic structure which overlies the dorsal aspect of the user's foot in use.

11. A prophylactic device according to any preceding claim, wherein the sole is of rubber, plastics, silicone or any like material(s), or a combination of these.

12. A prophylactic device according to Claim 11, wherein sole is of latex rubber or polyurethane.

13. A prophylactic device according to any preceding claim, wherein the sole is permanently affixed to the elastic structure.

14. A prophylactic device according to Claim 13, wherein the sole is adhered, sewn or fixed by means of one or more fixings to the elastic structure.

15. A prophylactic device according to Claim 14, further comprising an insole provided inside the second tubular member.

16. A prophylactic device according to Claim 15, wherein said sole is affixed through said elastic structure to said insole.

17. A prophylactic device according to Claim 15, wherein said insole is affixed through the elastic structure to a fixing layer provided on the outside of the elastic structure, and said sole is adhered or otherwise affixed to said fixing layer.

18. A prophylactic device according to Claim 17, wherein the fixing layer and/or the insole is of rubber.

19. A prophylactic device according to Claim 13, wherein the sole is formed directly onto the elastic structure.

20. A prophylactic device according to any preceding claim, wherein said first tubular member is sized so as to terminate, at a proximal end thereof, in the vicinity of the user's knee.

21. A prophylactic device according to any of Claims 1 to 19, wherein said first tubular portion is sized so as to terminate, at a proximal end thereof, in the region of the user's thigh.

22. A pair of tights having two leg portions, at least part of one of both of said leg portions comprising a prophylactic device according to any of Claims ltolg.

23. A prophylactic device according to any of Claims 1 to 21 or a pair of tights according to Claim 22, wherein said elastic structure comprises means to enable access to the foot and/or leg of the user, in use, for monitoring the user's circulation.

24. A prophylactic device according to any of claims 1 to 19 or a pair of tights according to Claim 22, wherein the elastic structure comprises surface decoration to improve the aesthetic appeal of the device.

25. A method of making a prophylactic device for thrombo-embolic disease, the method comprising providing an elastic structure formed of contiguous first and second tubular members, said second tubular member being set at an angle to the first tubular member to define, at least in use, a generally L-shaped cavity configured to accept and fit closely about at least part of the foot and leg of a user, wherein said elastic structure is configured to apply a compressive force to at least part of said foot and leg; and affixing a flexible and waterproof sole to at least part of a region of the elastic structure that overlies a plantar aspect of the user's foot in use.

26. A method according to Claim 25, comprising the step of providing an insole inside said second tubular member, and wherein said affixing step comprises affixing said sole to said insole through said elastic structure.

27. A method according to Claim 25, wherein said affixing step comprises forming said sole directly onto said elastic structure.

28. A method according to Claim 25, comprising the step of providing an insole inside said second tubular member, providing a fixing layer outside of said second tubular member, fixing said fixing layer to said insole through said elastic structure, and said affixing step comprises adhering or otherwise affixing said sole to said fixing layer.

29. A method according to Claim 28, wherein said insole and/or said fixing layer are of rubber.