LIMB STABILISATION APPARATUS AND METHODS

Abstract

A limb-stabilisation apparatus (100) comprises a limb-receiving container (110) arranged to receive a portion of the limb (5) and to collect blood exited from the limb; and a blood recirculation system (120) configured to recirculate blood from the limb-receiving container (110) to one or more regions of the limb. Advantageously, the limb-stabilisation apparatus (100) may further comprise or may be associated with a limb-compressing apparatus (210) configured to reduce, restrict or prevent blood flow in the region of the limb-compressing apparatus.

Claims

1. A limb-stabilisation apparatus comprising: a limb-receiving container arranged to receive a portion of the limb and to collect blood exited from the limb; and a blood recirculation system configured to recirculate blood from the limb-receiving container to one or more regions of the limb.

2. A limb-stabilisation apparatus according to claim 1, further comprising a limb-compressing apparatus configured to reduce, restrict or prevent blood flow in the region of the limb-compressing apparatus.

3. A limb-stabilisation apparatus according to claim 1, wherein the limb-receiving container is configured to receive a portion of the limb below the limb-compressing apparatus.

4. (canceled)

5. A limb-stabilisation apparatus according to claim 1, wherein the limb-receiving container comprises and/or defines a sump for collecting the blood exited from the limb and/or contained in the limb-receiving container.

6. A limb-stabilisation apparatus according to claim 5, wherein the blood recirculation system comprises a pump for pumping and/or circulating the blood, and wherein the pump is in fluid communication with the sump.

7. (canceled)

8. A limb-stabilisation apparatus according to claim 6, wherein the pump is capable of recirculating the blood to one or more regions of the limb.

9. A limb-stabilisation apparatus according to claim 6, wherein the pump is connectable to one or more cannulae for connection to a region of the limb.

10. (canceled)

11. A limb-stabilisation apparatus according to claim 6, wherein the apparatus comprises a cannulation router configured to guide pumped blood to one or more cannulae, wherein the cannulation router has at least one inlet, and a plurality of outlets, each outlet having an open and a closed position and being connectable to a respective cannula.

12.-15. (canceled)

16. A limb-stabilisation apparatus according to claim 1, wherein the limb receiving container comprises or is provided with a limb-suspension member configured to suspend the limb, in use.

17.-18. (canceled)

19. A limb-stabilisation apparatus according to claim 5, wherein the limb-stabilisation apparatus is configured to measure a level and/or volume of blood in the sump.

20. A limb-stabilisation apparatus according to claim 1, wherein the apparatus comprises, at least one blood pressure sensor for measuring pressure within the blood recirculation system.

21. A limb-stabilisation apparatus according to claim 6, wherein the pump may be is controllable and/or adjustable based on a measured blood pressure and/or blood level.

22. A limb-stabilisation apparatus according to claim 5, further comprising an external blood container configured to supply or feed external blood into the recirculation system if blood level and/or volume in the sump falls below a predetermined level.

23.-24. (canceled)

25. A method of treating a subject's limb, comprising: placing a subject's limb in a limb-receiving container arranged to receive a portion of the limb and to collect blood exited from the limb; and recirculating said blood from the limb-receiving container to one or more regions of the limb.

26. A method according to claim 25, comprising cannulating an arterial side of the limb to a blood recirculation system configured to recirculate blood collected in the limb-receiving container to one or more regions of the limb.

27. A method according to claim 26, comprising determining a desired pressure for the blood recirculation system, and activating the blood recirculation system so as to recirculate blood at the desired pressure.

28. (canceled)

29. A method according to claim 26, comprising monitoring the pressure and/or flow in the blood recirculation system, and/or comprising regulating and/or controlling blood flow and/or pressure within the blood recirculation system.

30. (canceled)

31. A method according to claim 25, comprising monitoring the blood levels in a sump.

32. A method according to claim 31, wherein, when the blood level in the sump is below a predetermined level, the method comprises one or more of the following: (a) stopping blood recirculation until blood level reaches the predetermined level; or (b) supplying external blood into the recirculation system.

33. A method according to claim 25, further comprising applying a limb-compressing apparatus on a region of the limb so as to reduce, restrict or prevent blood flow.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0091] Embodiments of the invention will now be given by way of example only, and with reference to the accompanying drawings, which are:

[0092] FIG. 1 a perspective view from above of a limb-stabilisation apparatus according to a first embodiment of the present invention;

[0093] FIG. 2 a perspective view from above of the limb-stabilisation apparatus of FIG. 1, in use;

[0094] FIG. 3 a perspective view from above of a limb-compressing apparatus for use with the limb-stabilisation apparatus of FIG. 1;

[0095] FIG. 4 a perspective view from above of another embodiment of a limb-compressing apparatus for use with the limb-stabilisation apparatus of FIG. 1;

[0096] FIG. 5 the apparatus of FIG. 4, in a deployed or in use configuration;

[0097] FIG. 6 a schematic view from above of a cuff of the apparatus of FIG. 4;

[0098] FIG. 7 a schematic side view of the sump of the apparatus of FIGS. 1 and 2.

DETAILED DESCRIPTION OF DRAWINGS

[0099] Referring to FIGS. 1 and 2 there are shown a perspective view from above of a limb-stabilisation apparatus, generally designated 100, according to a first embodiment of the present invention.

[0100] The limb-stabilisation apparatus 100 has a limb-receiving container 110 arranged to receive a portion of the limb 5, and to collect blood exited from the limb 5. The limb-stabilisation apparatus 100 includes a blood recirculation system 120 configured to recirculate blood from the limb-receiving container 110 to one or more regions of the limb 5.

[0101] Advantageously, the limb-stabilisation apparatus 100 is associated with and is located below a tourniquet 210 configured to reduce, restrict or prevent blood flow in the region of the tourniquet 210. This may assist in isolating the injured limb from the subject's circulatory system, and may help prevent or reduce bleeding and/or extremity haemorrhage exsanguination.

[0102] The limb-receiving container 110 is configured to contain blood. By such provision, the limb-receiving container 110 is capable of containing the blood exited/lost from the injured limb 5, thus ensuring that all the blood lost by the subject may be recirculated. The limb-receiving container 110 is rigid and is impermeable to liquids, e.g. blood.

[0103] The limb-receiving container 5 includes a sump 130 (as best shown in FIG. 7) for collecting blood exited from the limb and/or contained in the limb-receiving container 110.

[0104] The apparatus 100, and in this embodiment the blood recirculation system 120, includes a pump 122 for pumping and/or circulating the blood collected in the sump 130.

[0105] The apparatus 100 has comprise a sump connector 132 which provides fluid communication between the sump 130 and the pump 122.

[0106] Advantageously, the pump 122 is capable of recirculating blood to one or more regions of the limb 5. In the embodiment of FIG. 2, the pump 122 is in fluid communication with a cannula 125 which is connected to an arterial vessel of the limb 5. By such provision, the apparatus 100 can recirculate the blood lost by the limb 5 and collected into the sump 130 back into an arterial system of the limb 5, thus maintaining blood flow through the limb 5 in a simple and effective manner, for example prior to, or after, surgery.

[0107] In other embodiments, there may be provided a plurality of cannulations, each cannulation being connected to an arterial vessel upstream from an associated wound, e.g., upstream from a wound from which blood exits the vessel.

[0108] The apparatus 100 includes a lid 140. In this embodiment, the lid 140 is hingedly connected to the container 110 and can be opened and closed by a user. This may allow, in use, protection of the limb 5 and/or may provide a hygienic and/or sealed environment for a/the injured limb 5.

[0109] While the embodiment of FIGS. 1 and 2 shows a single lid 140, it will be appreciated at the lid 140 may be provided as a plurality of adjacent lids which can be opened and closed independently, thus allowing exposure of a limited region of the limb 5.

[0110] The lid 140 has a plurality of openings 142 in the form of holes configured to receive a medical tube such as a cannula 125, which openings 142 are provided at different positions in the lid 140. By such provision, a/the cannula 125 may be easily connected to a vessel, e.g. an arterial vessel, on the limb 5 at a location near a particular opening 142, in use.

[0111] Advantageously, the lid 140 is made of a transparent material. By such provision, a used may be able to connect a cannula 125 to an arterial vessel and/or may be able to monitor the apparatus 100 and/or the subject's limb 5, in use.

[0112] In this embodiment, the container 110 is opaque. However, it other embodiment, the container may also be transparent.

[0113] As best shown in FIG. 1, the container 100 includes a limb-suspension member 150 configured to suspend the limb 5, in use, from the bottom of the container 110. Advantageously, the limb-suspension member 150 allows the limb 5 to be supported within the container 110, while ensuring the limb 5 does not rest on or does not contact a substantial area of the container 110. This may provide a more hygienic environment, allowing the blood to exit vessels and/or wounds in the limb 5 and be collected in the sump 130 without significant or prolonged contact with an outer surface of the limb 5, e.g. skin thereof, thus reducing the risks of infection.

[0114] In this embodiment, the limb-suspension member 150 is provided in the form of a net or mesh 152. A net of mesh may provide adequate support to the limb 5, while helping blood drainage and/or collection into the container 110, e.g. blood sump 130.

[0115] The apparatus 100 also includes a blood oxygenating device 160 and a blood temperature control device 162. In this embodiment, a combined and/or integrated device 164 is provided which functions as a blood oxygenating device 160 and a temperature control device 162. By such provision, the device 164 may provide not only blood recirculation to the injured limb 5, but may also provide blood oxygenation thus providing the metabolic needs of the limb 5. The provision of a temperature control device 162, e.g. a cooling device, capability may also help reduce the oxygen requirements of the limb 5.

[0116] The limb-stabilisation apparatus 100 also includes a blood-treatment unit 170. The blood treatment unit 170 is configured to alter, e.g. to remove, certain components of the blood, and in this embodiment to filter one or more components of the blood that are susceptible of inducing or suppressing an inflammatory response in the subject such as cytokines.

[0117] As best shown in FIG. 7, the limb-receiving container 110 includes a sump 130 for collecting blood exited from the limb and/or contained in the limb-receiving container 110.

[0118] The blood sump 130 is located near a lower end of the limb-receiving container 110. In use, the limb-receiving container 110 is inclined such that the blood lost from the limb 5 flows to and/or is collected into the sump 130.

[0119] The blood sump 130 is provided with blood measuring means 131 for measuring the level and/or volume of blood in the sump 130. In this embodiment, the blood measuring means 131 are provided in the form of graduations 133, and also include sensor 134 configured to measure the level and/or volume of blood in the sump 130.

[0120] The apparatus includes a blood pressure sensor 125 for measuring the pressure within the blood recirculation system 120.

[0121] Advantageously, if the blood pressure within the pressure blood recirculation system 120 falls below a predetermined or desired value, the power of the pump 120 may be altered, for example in order to reach a predetermined or desired pressure.

[0122] If the blood level and/or volume in the sump 130 falls below a predetermined level, blood recirculation may be stopped, for example by shutting down the pump 122, e.g., until blood level in the sump 130 reaches a/the predetermined level

[0123] In this embodiment, as best shown in FIG. 2 there is also provided an external blood supply in the form of a blood bag 180. Advantageously, if the blood level and/or volume in the sump 130 falls below a predetermined level, external blood from the blood bag 180 can be fed into the recirculation system 120.

[0124] By such provision, the apparatus/system 100 ensures that, in the event that there are insufficient blood levels in the sump 130 to provide the desired blood pressure and/or blood flow, the recirculation system 120 does not cause air to be pumped into the subject. Advantageously, if the blood level and/or volume in the sump 130 falls below a predetermined level, the apparatus 100 automatically pumps external blood from the blood bag 180 into the recirculation system 120.

[0125] Referring now to FIG. 3, there is shown a perspective view from above of a limb-compressing apparatus 210 for use with the limb-stabilisation apparatus 100 of FIG. 1. The limb-compressing apparatus 210 is a dual tourniquet 210.

[0126] The tourniquet 210 has a pair of inflatable bladders 221,222, partially located within a housing 230. In this embodiment, the housing 230 is a rigid housing 230.

[0127] The housing defines an opening 232 for receiving a limb of a subject, e.g., a portion of an arm or a leg.

[0128] The bladders 221,222 are spatially arranged in a longitudinal direction along a axis of the housing 230 and opening 232. The bladders 221,222 share a common axis with the housing 230 and the opening 232.

[0129] The bladders 221,222 are provided adjacent to each other. In this embodiment, the bladders 221,222 are separated by a gap 224 having a size sufficient to allow inflation of each bladder without interference with the other bladder.

[0130] The housing 230 and/or opening 232 thereof is/are dimensioned so as to be capable of receiving a portion of a subject's limb. As such, the apparatus 210 is capable of receiving a subject's limb having a range of sizes, e.g., diameter. For example, the apparatus may be manufactured in a range of sizes, each size being designed to receive a predetermined range of limb sizes, for example corresponding to a typical region of a limb, e.g., a forearm, an arm, a lower leg (calf), or an upper leg (thigh).

[0131] The apparatus 210 has a gas inlet 240 configured to be connected to a pump (not shown) so as to independently and selectively inflate each bladder 221,222. The apparatus also has a pressure gauge or manometer 243 to monitor the pressure in the bladders.

[0132] Referring now to FIGS. 4 and 5, there is shown a tourniquet apparatus 310 according to a second embodiment of the present invention. The tourniquet 310 of FIG. 4 is similar to the tourniquet 210 of FIG. 3, like part denoted by like numerals, incremented by 100.

[0133] The tourniquet 310 also has a housing 330 and a pair of bladders 321,322. However, in this embodiment, the housing 330 is a flexible housing 330. The housing 330 has an inflatable elongate portion 336 which has been heat-sealed along a length thereof in its central region so as to define two separate inflatable bladders 321,322. The inflatable bladders 321,322 are made a PVC-coated polyester material which allows the tourniquet 310 to undergo repeated cycles of expansion and contraction, e.g. inflation and deflation, without mechanical damage.

[0134] The tourniquet 310 also has a non-inflatable cuff portion 338 at an upper end of the bladders, arranged to affix and secure the tourniquet 310 on a subject's limb, as will be explained later in more detail.

[0135] The tourniquet 310 has Velcro fasteners 328 to secure the tourniquet on a subject's limb.

[0136] FIG. 4 shows the tourniquet 310 in a non-inflated configuration, when not in use. FIG. 5 shows the tourniquet 310 in a deployed or in use inflated configuration. For illustration purposes, both inflatable bladders 321,322 are shown as inflated. However, the tourniquet 310 allows each bladder 321,322 to be inflated separately and/or independently, as will be explained later in more detail.

[0137] A manometer 343 is provided to measure pressure in the bladders 321,322.

[0138] FIG. 6 shows a schematic view from above of a cuff structure 311 of the tourniquet 310 of FIG. 4. The tourniquet 310 has a flexible housing 330 provided in the form of a cuff 311. The tourniquet 310 has an inflatable elongate portion 336 which has been heat-sealed along a length thereof in its central region so as to define two separate inflatable bladders 321,322. The tourniquet 310 also has a non-inflatable cuff portion 338 at an upper end of the bladders, arranged to affix and secure the tourniquet 310 on a subject's limb.

[0139] In this embodiment, the dimensions of the cuff 311 are selected to ensure that the tourniquet 310 is suitable for upper and lower limbs. As such, the cuff 310 was designed in accordance with dimensions stated by McDowell and colleagues in a 2008 National Statistics Report on Anthropometric Reference Data for Children and Adults in the United States between 2003-2006 (http://www.cdc.gov/nchs/data/nhsr/nhsr010.pdf), where the average adult mid-arm and mid-thigh circumferences were recorded as 39.4 cm and 55 cm, respectively.

[0140] Thus, in this embodiment, the cuff 311 had a total length L of 850 mm, and a total width W of 140 mm. The length L1 of the bladders was 600 mm, and the width W1,W2 of each bladder was 70 mm. The diameter d1,d2 of each port 151,152 for connecting to a pump inlet such as an inlet tube (not shown) was 14 mm.

[0141] It will be appreciated that the embodiments of the invention hereinbefore described are given by way of example only and are not meant to limit the scope thereof in any way.