ZA200604129B

ZA200604129B - Device for reducing the risk of the developing of deep vein thrombosis

Info

Publication number: ZA200604129B
Application number: ZA200604129A
Authority: ZA
Inventors: Van Wyk Johan David
Original assignee: Van Wyk Johan David
Priority date: 2003-11-14
Filing date: 2006-05-23
Publication date: 2007-11-28
Also published as: WO2005046803A1

Description

DEVICE FOR REDUCING THE RISK OF THE DEVELOPING OF DEEP VEIN

THROMBOSIS

FIELD OF THE INVENTION

The invention relates to a device for use in reducing th e risk of the developing of circulatory ailments in humans, and more particularly feor reducing the risk of the developing of deep vein thrombosis in persons beirg subjected to prolonged immobility. i

BACKGROUND TO THE INVENTION

Circulatory ailments generally relate to disorders in the blood circulation system, and one common circulatory ailment is deep vein thrombosis (DVT). DVT is a condition L that typically occurs when a blood clot develops in a ve=in, and usually occurs in the veins of the lower legs. A clot, so formed, will not onBy result in potentially severe pain and discomfort, but can also be life threatening. If a clot is large enough it may start to interfere with the circulation of blood in the affected area, and even block blood flow from the legs to the heart. In addition a bloo d clot may become dislodged from the vein where it was formed, and travel fo the lungs with potentially fatal consequences.

Various factors may influence and prompt the formation of blood clots in veins. Of major concer is the forming of blood clots due to poolimng of blood in the veins, which may in turn be caused by insufficient blood circulation. When a person, for instance, remains immobile for prolonged periods, the inactivity «of the leg muscles may cause the natural pumping action caused by flexing and reslaxing of the calf muscles to cease, thus resulting in pooling of the plood. © The probability of the occurrence of

DVT will further be increased by the presence of inherent risk factors, for example the use of medication that may render the blood more likely to clot, or vein walls being in a damaged condition.

DVT most frequently, albeit not exclusively, develops in the veins of the lower leg. of particular concem are the deep veins in the lower legs as well as the superficial veins in the lower legs (great and lesser saphenotis veins). DVT can also develop in the thigh, and even in the pelvis or arm regioras, but the occurrence of DVT in these areas are substantially less common.

Many solutions have been proposed to reduce the risk of DVT in persons subjected to limited mobility. A common preventative rmeasure is to take medication in the form of anti-coagulants that reduces the tendemcy of blood to clot. However, these medications may resutt in the risk of excessive bleeding should a person be injured, due to the very purpose why the medicatiory was administered. A further solution is to ensure that a person gets sufficient exercise so as to facilitate proper circulation via the natural pumping.action induced by flexing and relaxing of the muscles. It will however be appreciated that this is not always feasible, as the very reason for low mobility may be the inability to stand up, or may be the result of being confined to a small space such as when travelling by aeroplane. In certain situations a person may at most be able to do foot exercises such as rotating the ankle and wiggling the toes, which will assist to prevent blood pooling in the feet. However, these marginal exercises are by no means sufficient to result in proper blood circulation.

Various systems have been proposed for overcoming the shortcomings due to the inability to properly exercise the leg muscles. Most of these systems are aimed at mechanically inducing and/or improving blood circulation. One such system is the use of compression stockings, which comprises socks that are tighter at the foot than higher up the leg so that there is a pressure gradient from the foot to the knee.

Although this system does aid blood circulation , it will be appreciated that there is no active muscle flexing and relaxing, and the effecttis thus limited.

A still further preventative measure may be to Litilise devices that pressurises the feet by means of inflatable chambers located insicle a sock-like device. These devices may be limited to only covering a foot, but may” also be configured to extend up to the knee. In addition such devices may include a plurality of inflatable chambers that may be sequentially inflated and deflated so as to achieve a proper pumping action.

Typical examples of such devices are describead in United States Patents 4 624 244, 4 841 956 and 5 443 440. These type of devices substantially enhances blood circulation, but have the common disadvantage of requiring an extensive pressure - supply and control system, thus making the systems heavy and bulky and also rendering it unsuitable for use in situations where the user is not in the vicinity of a suitable power source.

OBJECT OF THE INVENTION

It is accordingly an object of this inventior to provide an alternative device for reducing the risk of the developing of deep vein thrombosis that will, at least partially, alleviate the disadvantages as mentioned hereinbefore.

SUMMARY OF THE INVENTION

According to the invention there is provided a device, suitable for reducing the risk of developing deep vein thrombosis in the human leg, the device comprising: a first engagement member, suitable for in use engaging a thigh of a human user of the device; a second engagement member, suitable to be engaged by a corresponding foot of the user when in use; the engagement members being resiliently connectable to one another; and being resiliently displaceable away from one another when a parting force is imparted on the connected exngagement members; and an abutment member for abutting a calf of the user when in use; the abutment member being located between the first engagement member and the second engagement-member; and the abutment member in use ‘being displaceable relative to one of the engagement members, and substantially stationary relative to another of the engagement members thereby to be displaced relative to the calf when the engagement members are displaced relative to one another.

The abutment member in use may be displaceable relative to the first engagement member, and substantially stationary relative to the second engagement member,

There is further provided for the first engagement member and a first end of the abutment member to be connected by way of an elastic connecting means, and for the second engagement member and an opposing end of the abutment member to be connected by way of an inelastic connecting means.

The elastic connecting means may be in the form of an elongate rubber band, and the inelastic connecting means may be in the form of a cord made of inelastic material.

Alternatively there is provided for the abutment member to be connected to an inelastic connecting means exteanding from the second engagement beyond the abutment member towards the firsst engagement member.

A further feature of the invention provides for the first engagement member 10 comprise at least two primary co-nnecting members being inter-connectable so as to form a loop suitable for engaging the thigh.

The primary connecting members may be adjustably connectable relative to one another so as to adjust the size of the loop, and thus the distance between the first engagement member and the absutment member.

There Is further provided for the first engagement member to include secondary connecting members extendimg from the primary connecting members, the secondary connecting memberss being adjustably connectable to one another so as : to form an intermediate link be€ween the primary connecting members, in so doing : enabling the first engagement meember to completely encircle a human thigh.

The first engagement member rnay further include a finer disposed towards an inner surface of the first engagement member, the finer being configured to be interposed between the connecting membeers and the thigh when In use.

The liner may include at least «one gap toward an operatively upper part of the first engagement member.

There is provided for the liner to be made from foam rubber or other forms of padding.

A still further feature of the invention provides for the second engagement member to comprise a ring-like structusre made from at least partially tubuiar, flexible material.

An aperture formed by the ring-like structure may define a foothold for receiving a human foot.

The ring-like structure may be diametrically adjustable for snugly receiving feet of different sizes.

The second engagement member may also include a rigid support member being encapsulated in a remotes part of the ring-like structure, with the inelastic connecting means being securable to ends of the rigid support member.

The second engagement member may further include a foot-retaining member for retaining a foot in the ringg-like structure.

The foot-retaining member may be in the form of a pliable sheet extending between opposing sides of the ring-like structure.

A yet further feature of the invention provides for the abutment member to comprise a pliable sheet extending between two spaced apart side supports.

The side supports may Ibe substantially rigid so as to prevent the pliable sheet from folding when the abutmeant member is displaced relative to a calf of a user.

In yet a further embodiment there is provided for the abutment member to comprise a plurality of spaced apart elongate sections extending between opposing side supports.

The abutment member according to this embodiment may include rollers mounted on the elongate sections, the rollers being adapted to rotate about the elongate sections when the abutment member is displaced relative to the calf.

In a further embodiment the abutment member may be substantially rigid and semi- cylindrical so as to approximate the shape of a human calf. The abutment member may in addition be at least partially conical so as to more accurately approximate the shape of a human calf.

At least one edge of the abutment member may be outwardly flared so as to prevent the edge from biting intos the calf when the abutment member is displaced relative to the calf. Preferably both edges that are orientated transverse to the direction of displacement of the abutment member will be outwardly flared.

The abutment member may also include a pliable bladder located on an inner surface thereof.

The bladder may compsise a pocket filled with a yieldable medium such as silicon gel, a lubrication fluid or air.

According to a further asspect of the invention thers is provided a method for reducing the risk of developing deep vein thrombosis in the lower leg including the steps of: connecting the device according to any of the preceding claims to the leg of a user;

extending the lower leg until a lower leg is at an obtuse angle relative to an upper leg; and oscillating a foot engaging the device between a relaxed position, wherein the foot is substantially perpendicular to the lower leg, and a flexed position, wherein the foot is at an obtuse angle relative to thee lower leg.

BRIEF DESCRIPTION OF THEE DRAWINGS

Embodiments of the invention are described by way of non-limiting examples, and with reference to the accompanying drawings in which:

Figure 1 shows a first embodiment of a device for preventing deep vein thrombosis in accordance with the invention;

Figure 2 shows a second embodiment of the device of figure 1;

Figure 3 shows a third embodiment of the device of figure 1;

Figure 4 shows a fourth embodiment of the device of figure 1;

Figure 5 is a perspective view of a calf abutment member in accordance with the invention;

Figure 6 is a perspective view of a foot support member in accordance with the invention;

Figure 7 is a cross-sectional front view of the foot support member of figure 6, with the foot su pport member in a relaxed position;

Figure 8 shows the foot support member of figure 7 in the contracted position; and

Figure 9 shows the device of figure 1 in use or a human leg.

DETAIL DESCRIPTION OF THE INVENTION

With reference to the drawings, in which like numerals indicate like features, a device for use in preventing deep vein thrombosis is generally indicated by reference numeral 10. The device 10 includes a first en gagement member 12, which is suitable adapted to engage a thigh of a human Beg, an abutment member 30 for abutting a calf of the leg, and a second engagement member 40 suitable for receiving a foot of a user. Various embodiments of the first engagement member 12, abutment member 30 and second engagement member 40 are described in more detail hereinbelow. It will be appreciated that any combination of these components can be combined in order to obtain any suitable arrangement.

The first engagement member 12 may comprise various configurations, as is for example depicted in figures 1, 2 and 3. The first engaging member 12 typically comprises a pair of elongate primary connection rmembers 14, which may be in the form of elastic chords as is shown in figure 1, or substantially rigid flat strips as shown in figures 2 and 3. A connecting mechanisrn 16 is used to adjustably connect the pair of primary connection members 14. The connection members 14 can thus be adjusted so as to fit the thigh of a particular usser. The connection members 14 form a loop 17 that can be fitted around the uppe r part of the thigh of a user of the device. The first engaging member 12 as shown in figure 1 may also comprise two or mmore pairs of elongate primary connection members 14 being disposed substantially parallel relative to one another.

The first engagement means 12, as shown in figures 2 and 3, also irmclude an upper linasr 18 made of a soft, resilient material such as foam rubber, which in use is sandwiched between the connecting members 14 and the thigh of th e user, so as to distribute the forces imparted in use on the leg of the user. Distribution of such forces serves to prevent pain due to the connecting members biting #into the leg, and also to prevent excessive forces being exerted on the great saphenotis vein.

In the embodiment shown in figure 3, the first engagement member 12 includes a pair of secondary connecting members 20, which is again adjustablyy connectable by "means of a connecting mechanism 21. In this arrangement the first engagement member completely encircles the upper leg of the user so as to result in a more seacure connection. A lower liner 22 is interposed between the leg ard the secondary connecting members 20 for the reason as set out before. A gap 23 is left between th e upper liner 18 and the lower liner 22 so as to prevent excesssive forces being: exerted on the great saphenous vein.

The abutment member is generally indicated by reference numeral 30, and three non-exhaustive embodiments of the abutment member are shown im figures 1, 2 and 4 respectively. The abutment member as shown in figure 1 commprises a pliable sheet 39 extending between two opposing side supports 38. The pliable sheet 39 may be made of substantially inelastic material such as cotton, denim, leather or a thin sheet of polymeric material, but may alternatively be made fro-m elastic material such as rubber or stretchable denim. A pliable bladder 33 may be located on an irmner surface of the abutment member for assisting in reducing the friction of the abutment member relative to the calf of the user. The bladder 33 may for instance be in the forrm of a pocket filled with silicone gel, a jubricating fluid or air, and may be interposed b etween two layers of material making up the pliable stmeet 39 of the abutment member 30. It will however be appreciated that such bladder 33 is by no means essential, and that the device 10 can be used without it.

The abutment member as shown in figure 2 comprises a semi-cylindric=al open sleeve 31 which is at least partially conical in order better to match the profile of the user's calf. Upper and lower edges 32 of the abutment member 30 are outvwardly flared so as to prevert the edges of the abutment member to bite into the calf off a user when it is displaceds relative to the calf. A pliable bladder 33 may again be located on an inner surface 37 of the abutment member 30. In this embodiment the abutment member memy be connected to the first 12 and second 40 engagement members in a plurality of ways. In a first method two pairs of inelastic connectimg means may extend from opposing sides of the abutment member 30, and may for instance be connected to receiving apertures provided on the abutment member. This method of attachment is shown in figure 1. A further option, as shown in figure 5, may be to provide hook formations 60 on the abutment members. These hook formations 60 =~ : are suitably dimensioned to engage a rubber sleeve 61 that is located on the inelastic - connecting means 26. The connection between the hook formation=s 60, sleeve 61 and Inelasgic connecting means 26 are sufficiently tight to prevermt the abutment member 30 from being displaced relative to the second engagemeent member 40 when in use. However, it is possible to move the abutment member 30 by hand so as to adjust the distance between the abutment member 30 and second engagement member 40 if required. In addition, this configuration provides for easy replacement of the abutament member 30 with an abutment member of smaller or | arger size so as to accommodate different calf sizes.

A further embodiment of the abutment member 30 is shown in figure 4. In this case the abutment member comprises a plurality of spaced apart elongate sections 35 extending between opposing side supports 38 of the abutment member. Thes elongate sections 35 shwown in the particular embodiment are in the form of inelastic strings, but it will be appreciated that elongate rods, or partially elastic chord may also be used. A plurality of rollers 36 are mounted on the elongate sactions 35, ancl are adapted to rotate aloout the elongate sections 35 when the abutment member 3Q is displaced relative to the calf of a user. The rollers 36 depicted in figure 4 is of & spherical configuration, but any shape that would allow easy rotation will suffice. Th e rollers may for instances be oval or cylindrical.

The upper end of the abutment member 30 is connected to the first engagememt member 12 by meanss of elongate, resilient connection means 25 which may fer instance be in the forrm of rubber bands. The resilient connection means allow the abutment member 30 to be resiliently displaceable relative to the first engageme=nt member 12. A lower end of the abutment member 30 is connected to the secord engagement member 40 by means of elongate, inelastic connection means 26 whi«ch may for instance be ira the form of an inelastic string or chard. The rigid and inelas tic connection means ca uses the abutment member 30 to be stationary relative to the first engagement menmiber 12.

The second engagement member 40 is described in more detail with reference to figure 6 to 8. One embodiment of the second engagement member 40 typically comprises a ring-like structure 41 or stirrup, which is at least partially tubular so ass to define a passage 43 for receiving the inelastic connection means 26 therein. Ari gid foot support member 42, which may for instance be in the form of a flat elastomeric strip or a substantiallly rigid rubber rod, is located inside the passage 43 in the ri ng- like structure 41. Thee rigid foot support member 42 is shorter than the width of the foot of a user, and-ends of the foot support member are connected to ends of the inelastic connection means 26. When a force is exerted on the inelastic connection means 28, the ring-like structure 41 is deformed in the direction indicated by arrow A in figure 8. This causes a foot (not shown) of a user to be gripped by the contracted ring-like structure 41 so as to prevent the foot from moving relative to the second engagement member 40 or stirrup. The second engagement member 40 or stirrup may also include a foot-retaining memfkoer 44 that abuts the front part of a foot when in use, so as to prevent the foot from p rotruding too far through the ring-like structure 41. The foot-retaining member is typically in the form of a pliable sheet extending between opposing sides of the ring-likce structure 41. The foot-retaining member 44 may include an aperture 45 for receiving the front end of the foot, and may altematively be dish-shaped so as to approximate the profile of the front end of the foot. The circumference of the ring-like structure 41 is furthermore adjustable in : order ta accommodate feet of different sizes.

The use of the device 10 is described with reference to figure 9 in which a human leg 53 is shown to include a thigh 50, calf 51 and foot 52. A purely schematic representation of the device 10 as de scribed hereinbefore is mounted on the lag 53 so that the first engagement member 12 engages the thigh 50, and the foot engages the second engagement member 4Q or stirrup. The foot is kept in position by abutting the foot retaining cover 44 whilst simultaneously being gripped by the contracted ring-like structure 41 as described hersinbefore. The leg is now slightly extended to form an angle of approximately 135 degrees, and a slight force is exerted on the resilient connecting mesans 25.

The forces exerted on the device 10 are essentially in the directions as indicated by arrows B and C. Due to the orientation of the leg the first engagement member 12, abutment member 30 and second ersgagement member 40 form an arc indicated by broken line D. The forces B and C are applied to the ends of the arc D, and thus induce a resultant force E on the abutment member that forces the abutment member into contact with the calf 51.

Once the device 10 has been installed as per figure 9, the Liser pushes down with his or her foot 52 against the resilience provided by the elastic connecting means 25, as is indicated by arrow F. The large muscles in the calf, being the soleus and gastronemius muscles, are used to effect this foot movement, and repetitive flexing and relaxing of these muscles result in increased arterial blood flow. As the foot move back towards a relaxed position, the abutment member is displaced upwardly relative to the calf, and imparts a frictional and normal force on the calf due to resultant force E acting on the abutment member. The net result is that a massaging action is applied to the calf, and more particularly to the Ewo large superficial veins, : being the greater and lesser saphenous veins, so as to stimulate the venous outflow of the leg. It will be appreciated that the effect of repetitives flexing and relaxing of the soleus and gastronemius muscles, combined with the massaging action due to the abutment member, will result in at least improving and ideally maintaining proper blood circulation in the leg, and more particularly the lower leg. it will be appreciated that this invention will solve or at least alleviate the problems associated with the prior art in that the device 10 is cosmpact, does not need any external support or utilities, and still succeeds in at least improving blood circulation. it will be further appreciated that the above are only some embodiments of the invention, and that many variations are possible without deeparting from the spirit and scope of the invention.

Claims

1. A device, sultable for reducing the risk of developing deep vein thrombosis in the human leg, the device comprising: a first engagement member, suitable in use for engaging a thigh of a human user of the device; a second engagement member, suitable to be engaged by a corresponding foot of the user when in use; the engagement membess being resiliently connectable to one another; and being resiliently displaceable away from one another when a parting force is imparted on the connected engagement members; and an abutment member for abutting a calf of the user when in uss; the abutment member being located between the first engagement member and the second ergagement member; and the abutment member in use being displaceable relative to one of the engagement members, and substantially stationary relative to the other of the engagement nnembers, thereby to be displaced relative to the calf when the engagernent members are displaced relative to one another.

2. The device according to claim 1 wherein the abutment member in use is displaceable relative to the first engagement member, and substantially stationary relative to the second engagement member.

3. The device according to any of claims 1 or 2 wherein the first engagement member and the abutment member is connected by way of an elastic connecting means, and the second engagement member and the abutment member is connected by way of an inelastic connecting means.

4. The device according to any of claims 1 or 2 wherein the abutment member is connected to an inelastic connecting means extending from the second engagement beyond the abutment member towards the first engagement member.

5. The device according to claim 4 wherein an elastic connecting means is connected to an end of the inelastic connecting means.

6. The device according to any of the preceding claims wherein the elastic connecting means is in the form of an elongate rubber band.

7. The device according to any of claims 1 to 5 wherein the inelastic connecting means is in the form of a cord or string made of inelastic material.

8. The device according to any of the preceding claims wherein the first engagement member comprises at lexast two primary connecting members being inter-connectable so as to form a. loop suitable for engaging the thigh.

9. The device according to claim 8 wherein the primary connecting members are adjustably connectable relative to one another so as to adjust the size of the loop and the distance between the first engagement member and the abutment member.

10. The device according to claim 8 or 9 wherein the first engagement member includes secondary connecting members extending from the primary connecting members, the secondary conmecting members being adjustably connectable to one another so as to form an intermediate fink between the primary connecting members thereby to enable the first engagement member to completely encircle a human thigh.

11. The device according to any of the pereceding claims wherein the first engagement member includes a liner disposed towards an inner surface of the first engagement member, the liner being configured to be interposed between the first engagement member an d the thigh when in use.

12. The device according to claim 11 wherein the liner includes at least one gap disposed towards an operatively upper pamrt of the first engagement member.

13. The device according to claim 11 or 12 wherein the liner is made from foam rubber.

14. The device according to any of the preceding claims wherein the second engagement member comprises a ring-like structure made from at least partiaily tubular, flexible material.

15. The device according to claim 14 wherein the ring-like structure forms an aperture that defines a foothold for receiving a human foot.

16. The device according to claim 14 or 1 5 wherein the ring-like structure is diametrically adjustable for snugly receivimng feet of different sizes.

17. The device according to any of claims 14 to 15 wherein the second engagement member includes a rigid support member being encapsulated in a remote part of the ring-like structures, with the inelastic connecting means being securable to ends of the rigid support member.

18. The device according to any of claims 14 to 17 wherein the second engagement member includes a foot-restaining member for retaining a foot in a the ring-like structure.

19. The device according to claim 18 wherein the foot-retaining member is in the form of a pliable sheet extending between opposing sides of the ring-like structure.

20. The device according to any of the preceding claims wherein the abutment member comprises a pliable sheet extending between two spaced apart side supports.

21. The device according to claim 20 wherein the side supports are substantially rigid so as to prevent the pliable sheet from folding when the abutment member is displaced relative to a calf of a user.

22. The device according to any of claims -1 to 19 wherein the abutment member comprises a plurality of spaced apart elongate sections extending between opposing side supports.

23. The device according to claim 22 wherein the abutment member includes a plurality of rollers mounted on the elongate sections, the rollers being adapted to rotate about the elongate sections whaen the abutment member is displaced relative to the calf.

24. The device according to any of claims 1 to 23 wherein £he abutment member is substantially rigid and semi-cylindrical so as to approximate the shape ofa human caff.

25. The device according to claim 24 wherein the abutme=nt member is at least partially conical so as to more accurately approximate the shape of a human ’ calf.

26. The device according to claim 24 or 25 wherein at | east one edge of the abutment member is outwardly flared so as to preven t the edge from biting into the calf when the abutment member is displaced re lative to the calf.

27. The device according to claim 26 wherein both edges that are orientated transverse to a direction of displacement of the a butment member are outwardly flared.

28. The device according to any of the preceding claims wherein the abutment member includes a pliable bladder located on an inner ssurface thereof.

29. The device according to claim 28 wherein the bladder comprises a pocket filled with a yieldable medium.

30. The device according to claim 29 wherein the yieldabsle medium is selected from the group consisting of silicon gel, a lubrication flui-d and air.

31. A method for reducing the risk of developing deep wwein thrombosis in the lower leg including the steps of:

connecting the device according to any of the preceding claims to the leg of a user; extending the lower leg until a lower leg is at an obtuse ang le relative to an upper leg; and oscillating a foot engaging the device between a relaxed posittion, wherein the foot is substantially perpendicular to the lower leg, and a flexed position, wherein the foot is at an obtuse angle relative to the lower leg -