TOURNIQUET AND TISSUE PRESERVATION SYSTEM

Abstract

A tourniquet apparatus (10) comprises at least two expandable members (21,22) configured for applying pressure on a limb of a subject; and actuating means (143,144) for actuating the at least two expandable members (21,22), wherein the actuating means (143,144) are configured to actuate each expandable member independently and/or selectively. There is also provided a limb-cooling apparatus (200) comprising an inner stretchable layer (210) configured to engage and/or contact a limb of a subject; an outer layer (220) at least partially attached to the inner layer (210); and a cooling system (240) configured to supply a cooling medium (250) between the inner layer (210) and the outer layer (220).

Claims

1. A tourniquet apparatus comprising: at least two expandable members configured for applying pressure on a limb of a subject; and an actuator coupled to the at least two expandable members, wherein the actuator is configured to actuate to inflate each expandable member independently and/or selectively.

2. A tourniquet apparatus according to claim 1, comprising a pair of expandable members as the at least two expandable members.

3. A tourniquet apparatus according to claim 1, wherein the apparatus comprises a housing, the expandable members being provided or located at least partially within the housing.

4.-5. (canceled)

6. A tourniquet apparatus according to claim 3, wherein the expandable members at least partially extend along an inner circumference or surface of the housing and are spaced apart in a longitudinal direction or axis of the apparatus.

7. (canceled)

8. A tourniquet apparatus according to claim 1, wherein each of the at least two expandable members is inflatable independently.

9. A tourniquet apparatus according to claim 1, wherein the at least two expandable members comprise first and second expandable members, wherein the apparatus is configured such that when the second expandable member is actuated from a deflated stowed configuration to an inflated configuration so as to compress a subject's limb, the first expandable member is moved from an inflated configuration to a deflated configuration.

10. (canceled)

11. A tourniquet apparatus according to claim 1, wherein the apparatus comprises a control valve or switch coupled to the actuator and configured to selectively inflate one or more of the at least two expandable members.

12. A tourniquet apparatus according to claim 11, wherein the control valve or switch has an inlet in communication with the actuator, and a plurality of outlets comprising at least a first outlet and a second outlet, each outlet being in communication with an associated expandable member of the at least two expandable members, wherein the control valve or switch has a first open position in which the inlet is in fluid communication with the first outlet, and a second open position in which the inlet is in fluid communication with the second outlet.

13. (canceled)

14. A tourniquet apparatus according to claim 12, wherein the control valve or switch is configured such that, in a third or intermediate position, the first outlet is in fluid communication with the second outlet.

15. A tourniquet apparatus according to claim 12, wherein the control valve or switch is configured such that, in a third or intermediate position, the inlet is in fluid communication with the first outlet and the second outlet.

16. A tourniquet apparatus according to claim 11, wherein the at least two expandable members comprise first and second expandable members, wherein the apparatus further comprises a deflating mechanism to allow selective and/or independent deflation of the expandable members, wherein the control valve or switch comprises the deflation mechanism, the control valve or switch having a first pressure release valve associated with the first expandable member and/or a first outlet when the control valve or switch is in a second open position, and a second pressure release valve associated with the second expandable member and/or a second outlet when the control valve or switch is in a first open position.

17. (canceled)

18. A tourniquet apparatus comprising: a cuff or sleeve configured for engaging with a limb of a subject; at least two inflatable bladders configured for applying pressure on the limb of the subject in an inflated configuration; and an actuator coupled to the at least two inflatable bladders, wherein the actuator is configured to actuate each inflatable bladder independently and/or selectively.

19. A limb-cooling apparatus comprising: an inner stretchable layer configured to engage and/or contact a limb of a subject; an outer layer at least partially attached to the inner layer; and a cooling system configured to supply a cooling medium between the inner layer and the outer layer.

20. A limb-cooling apparatus according to claim 19, wherein the inner layer is made of a stretchable fabric, and wherein the inner layer is thermally conductive.

21. (canceled)

22. A limb-cooling apparatus according to claim 19, wherein the outer layer is a thermally insulating layer.

23. A limb-cooling apparatus according to claim 19, wherein the outer layer and the inner layer define at least one space therebetween, wherein the outer layer and the inner layer are attached in a longitudinal direction so as to define a plurality of channels between the inner layer and the outer layer.

24.-25. (canceled)

26. A limb-cooling apparatus according to claim 19, wherein the cooling system comprises a delivery system for the cooling medium, the delivery system comprising tubing configured for feeding the cooling medium between the inner layer and the outer layer, wherein the tubing comprises a microporous tubing, wherein the tubing is attached to or secured to a support layer configured to maintain the position and/or arrangement of the tubing, in use.

27.-28. (canceled)

29. A limb-cooling apparatus according to claim 19, wherein the apparatus comprises one or more temperature indicators attached to and/or provided on or within at least a portion of the outer layer.

30.-32. (canceled)

33. A system comprising: a tourniquet apparatus comprising: at least two expandable members configured for applying pressure on a limb of a subject; and an actuator coupled to the at least two expandable members, wherein the actuator is configured to actuate to inflate each expandable member independently and/or selectively; and a limb-cooling apparatus comprising: an inner stretchable layer configured to engage and/or contact the limb of the subject; an outer layer at least partially attached to the inner layer; and a cooling system configured to supply a cooling medium between the inner layer and the outer layer.

34. A method of restricting blood flow to a subject's limb, comprising: applying a tourniquet apparatus on the limb of a subject, the tourniquet apparatus comprising at least two expandable members; and actuating each expandable member independently and/or selectively.

35. The method of claim 34, comprising actuating each expandable member alternately.

36. A method of cooling a subject's limb, comprising: applying a limb-cooling apparatus on a subject's limb, the apparatus comprising an inner stretchable layer configured to engage and/or contact a limb of a subject, and an outer layer at least partially attached to the inner layer; and supplying a cooling medium between the inner layer and the outer layer.

37. (canceled)

Description

BRIEF DESCRIPTION OF DRAWINGS

[0125] Embodiments of the invention will now be given by way of example only, and with reference to the accompanying drawings, which are:

[0126] FIG. 1 a tourniquet apparatus according to a first embodiment of the present invention;

[0127] FIG. 2 a tourniquet apparatus according to a second embodiment of the present invention, before use;

[0128] FIG. 3 the apparatus of FIG. 2, in a deployed or in use configuration;

[0129] FIG. 4 a schematic view from above of a cuff of the apparatus of FIG. 2;

[0130] FIG. 5 a valve connector used in the apparatus of FIG. 2;

[0131] FIG. 6 components of the valve connector of FIG. 5;

[0132] FIG. 7 a perspective view of a control valve or switch for use in the apparatus of FIG. 1 or FIG. 2;

[0133] FIG. 8 an exploded view of the control valve or switch of FIG. 7;

[0134] FIG. 9 an elevated front view of the control valve or switch of FIG. 7 in a first open position;

[0135] FIG. 10 an elevated front view of the control valve or switch of FIG. 7 in a second open position;

[0136] FIG. 11 a view from above of an embodiment of a tourniquet apparatus according to the present invention, equipped with a hand pump;

[0137] FIG. 12 a view from above of another embodiment of a tourniquet apparatus according to the present invention, equipped with a foot pump;

[0138] FIG. 13 a perspective view of the tourniquet apparatus of FIG. 11, including Velcro fasteners;

[0139] FIG. 14 a view from above of the tourniquet apparatus of FIG. 12, including Velcro fasteners;

[0140] FIG. 15 a perspective view of the tourniquet apparatus of FIG. 13, in a folded configuration;

[0141] FIG. 16 a perspective view of the tourniquet apparatus of FIG. 13, applied on a limb of a subject;

[0142] FIG. 17 a perspective view of a limb-cooling apparatus according to an embodiment of the present invention;

[0143] FIG. 18 a view from above of the limb-cooling apparatus of FIG. 17, including a cooling medium delivery system;

[0144] FIG. 19 an enlarged view of a connection mechanism for connecting a cooling medium supply to the apparatus of FIG. 18;

[0145] FIG. 20 a view from a above of a tubing arrangement used in an alternative embodiment of a limb-cooling apparatus according to the present invention;

[0146] FIG. 21 a view from above of an embodiment of a thermal indicator used with the limb-cooling apparatus of the present invention;

[0147] FIG. 22 a limb-compressing and cooling system according to an embodiment of the present invention;

[0148] FIG. 23 a limb-compressing, cooling and protecting system according to an embodiment of the present invention.

DETAILED DESCRIPTION OF DRAWINGS

[0149] Referring to FIG. 1 there is shown a tourniquet apparatus, generally designated 10, according to a first embodiment of the present invention. The tourniquet apparatus 10 may be generally termed a tourniquet.

[0150] The tourniquet 10 comprises a pair of inflatable bladders 21,22, partially located within a housing 30. In this embodiment, the housing 30 is a rigid housing 30.

[0151] The housing defines an opening 32 for receiving a limb of a subject, e.g., a portion of an arm or a leg.

[0152] The bladders 21,22 are spatially arranged in a longitudinal direction along a axis of the housing 30 and opening 32. The bladders 21,22 share a common axis with the housing 30 and the opening 32.

[0153] The bladders 21,22 are provided adjacent to each other. In this embodiment, the bladders 21,22 are separated by a gap 24 having a size sufficient to allow inflation of each bladder without interference with the other bladder.

[0154] The housing 30 and/or opening 32 thereof is/are dimensioned so as to be capable of receiving a portion of a subject's limb. As such, the apparatus 10 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).

[0155] The apparatus 10 has a gas inlet 40 configured to be connected to a pump (not shown) so as to independently and selectively inflate each bladder 21,22. The apparatus also has a pressure gauge or manometer 43 to monitor the pressure in the bladders.

[0156] Referring now to FIGS. 2 and 3, there is shown a tourniquet apparatus 110 according to a second embodiment of the present invention. The tourniquet 110 of FIG. 2 is similar to the tourniquet 10 of FIG. 1, like part denoted by like numerals, incremented by 100.

[0157] The tourniquet 110 also has a housing 130 and a pair of bladders 121,122. However, in this embodiment, the housing 130 is a flexible housing 130. The housing 130 has an inflatable elongate portion 136 which has been heat-sealed along a length thereof in its central region so as to define two separate inflatable bladders 121,122. The inflatable bladders 121,122 are made a PVC-coated polyester material which allows the tourniquet 110 to undergo repeated cycles of expansion and contraction, e.g. inflation and deflation, without mechanical damage.

[0158] The tourniquet 110 also has a non-inflatable cuff portion 138 at an upper end of the bladders, arranged to affix and secure the tourniquet 110 on a subject's limb, as will be explained later in more detail.

[0159] FIG. 2 shows the tourniquet 110 in a non-inflated configuration, when not in use. FIG. 3 shows the tourniquet 110 in a deployed or in use inflated configuration. For illustration purposes, both inflatable bladders 121,122 are shown as inflated. However, the tourniquet 110 allows each bladder 121,122 to be inflated separately and/or independently, as will be explained later in more detail.

[0160] A manometer 143 is provided to measure pressure in the bladders 121,122.

[0161] FIG. 4 shows a schematic view from above of a cuff structure 111 of the tourniquet 110 of FIG. 2. The tourniquet has a flexible housing 130 provided in the form of a cuff 111. The tourniquet 110 has an inflatable elongate portion 136 which has been heat-sealed along a length thereof in its central region so as to define two separate inflatable bladders 121,122. The tourniquet 110 also has a non-inflatable cuff portion 138 at an upper end of the bladders, arranged to affix and secure the tourniquet 110 on a subject's limb.

[0162] In this embodiment, the dimensions of the cuff 111 are selected to ensure that the tourniquet 110 is suitable for upper and lower limbs. As such, the cuff 110 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.

[0163] Thus, in this embodiment, the cuff 111 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.

[0164] Referring to FIGS. 5 and 6, there is shown a valve connector 155 used in the apparatus of FIG. 2 or with the cuff structure 111 of FIG. 4.

[0165] As shown in FIG. 5, the valve connector 155 provides a sealed connection between a tube 145 and a respective bladder 121,122. The valve connector includes a connector housing 156, which is sealably secured to port 152 of bladder 121,122 via first seal 157 and second seal 158. The connector housing 156 has a tube connector 159 to connected a tube 145, which tube 145 can be connected to a pump, manometer 143, or a valve as described later in more detail.

[0166] Where the tourniquet has a first bladder 121 and a second bladder 122, there may be provided a first valve connector 155a between a first tube 145a and a first bladder 121, and a second valve connector 155b between a second tube 145b and a second bladder 122.

[0167] As shown in FIGS. 11 to 16, the tourniquet 110 is typically connected to one or more pumps capable of inflating bladders 121,122. In FIGS. 11, 14, 15 and 16, the pump is in the form of a sphygmomanometer 143, and in FIGS. 12 and 13 the pump is in the form of a foot pump 144. Although the present embodiments illustrate mechanically powered pumps, it will be appreciated that, in other embodiments, the pumps may be externally powered, e.g., may be electrically powered. In such instance there may be provided a power supply, e.g. a portable power supply such as a battery, capable of powering one or more actuators, e.g. pumps and/or any accessory therefor, such as a compressor.

[0168] Advantageously, the bladders 121,122 are connected to the pump 143,144 via a control valve 160 as shown in FIG. 7. FIG. 8 shows an exploded view of the control valve 160 of FIG. 7. The control valve 160 is configured to selectively actuate of one or both bladders 121,122, by the associated pump 143,144. Thus, the control valve 160 allows selective inflation of one or both bladders 121,122.

[0169] The control valve 160 has an inlet 163 in communication with an associated pump 143,144. The control valve 160 has two outlets 161,162, each outlet being in communication with a respective bladder 121,122. It will be appreciated that, where the tourniquet 110 may have more than two bladders, the control valve may have more than two outlets, such that each outlet may be associated with a respective bladder.

[0170] In use, the valve may be controlled so as to be closed or open. When the valve is open, the valve may be configured to allow air to pass through at least one outlet.

[0171] As best shown in FIG. 8, the control valve 160 has a valve housing 164 which includes or is connected to inlet 163, first outlet 161 and second outlet 162. The control valve 160 also has a valve switch 165 which together with the valve housing 164 define a valve chamber 166 which is sealed by using a valve seal 167. The valve switch 165 is rotatable relative to the valve housing 164 so as to define a fluid passageway (now shown) between the inlet 163, first outlet 161 and/or second outlet 162.

[0172] The valve 160 is configured so as to allow fluid communication between the inlet 163 and the first outlet 161 in a first open configuration, as shown in FIG. 9. In this first open configuration, actuation of pump 143,144 inflates a first bladder 121. Thus, the valve switch 165 defines a fluid passageway represented by arrow A1, which, in the first open configuration, permits fluid communication between the inlet 163 and the first outlet 161.

[0173] The valve 160 is configured so as to allow fluid communication between the inlet 163 and the second outlet 162 in a second open configuration, as shown in FIG. 10. In this second open configuration, actuation of pump 143,144 inflates a second bladder 121. Thus, the valve switch 165 defines a fluid passageway represented by arrow A2, which, in the second open configuration, permits fluid communication between the inlet 163 and the second outlet 161.

[0174] The control valve 160 also has a deflating mechanism to permit deflation of the bladders 121,122, and in this embodiment to allow selective and/or independent deflation of each bladder 121,122.

[0175] The deflation mechanism includes pressure release valves 168,169. Which are be provided within the control valve 160. As best shown in FIGS. 9 and 10, the control valve 160 has two pressure release valves 168,169, each pressure release valve 168,169 being associated with a respective bladder 121,122 in a predetermined position. For example, as shown in FIG. 9, in the first open configuration, the second pressure valve 169 is in fluid communication with the second outlet 162 and thus acts as a vent for the second bladder 122. By such provision the second bladder 122 may be deflated via the second pressure release valve 169 when the control valve 160 is in a first open position. In contrast, as shown in FIG. 10, in the second open configuration, the first pressure valve 168 is in fluid communication with the first outlet 161 and thus acts as a vent for the first bladder 121. By such provision the first bladder 121 may be deflated via the first pressure release valve 168 when the control valve 160 is in a second open position.

[0176] In this embodiment, the valve 160 is configured such that, in an intermediate position between the first open position of FIG. 9 and the second open position of FIG. 10, the first outlet 161 is in fluid communication with the second outlet 162. By such provision, in use, pressure may be distributed between the first bladder 121 and the second bladder 122, such that, when the valve 160 is switched from a first open position to a second open position, the second bladder is already partially inflated and only requires a limited amount of additional pressure to reach its expanded configuration. Advantageously, the momentary release of pressure from the first bladder 121 during gas transfer between the first bladder 121 and a second bladder 122 may allow momentary and/or controlled bleeding of the limb, which may help flush stagnant blood in the injured limb and avoid prolonged ischemia, thus improving the likelihood of preserving the injured limb.

[0177] In alternative embodiments, the valve 160 may have a dual outlet configuration in which the valve 160 may allow air to pass through two or more outlets, e.g. two outlets, simultaneously, for example when the valve is moved from a first open position to a second open position. By such provision, if a user wishes to switch bladder, for example after a predetermined amount of time, this may ensure that the second bladder 122 is partially or fully inflated before the first bladder 121 is allowed to deflate, thus ensuring that the primary function of the tourniquet is maintained at all times.

[0178] As best shown in FIGS. 13 and 14, the tourniquet 110 has fastening means 125 for securing the tourniquet 110 on a subject's limb, as for example a subject's leg as shown in FIG. 16. In this embodiment, the fastening means 125 include hook and loop fasteners 126, e.g., Velcro. Conveniently, Velcro strips (e.g. loops) 127,128 have been provided on an outer surface of the cuff 111, and in this embodiment on an outer surface of the first bladder 121 and second bladder 122. A Velcro fastener (e.g. hooks) 129 has provided on a cuff portion 138 of the tourniquet 110. By such provision, in use, the tourniquet 110 may be placed on a subject's limb so as to engage the limb, the cuff portion 138 may be wrapped over and secured to the bladders 121,122 so as to bring the Velcro fastener 129 in contact with the Velcro strips 127,128, thus securing the apparatus 110 on the subject's limb.

[0179] Referring to FIGS. 17-21, there is shown a limb-cooling apparatus, generally designated 200, according to an embodiment of the present invention.

[0180] The limb-cooling apparatus 200 will be herein described in the context of a system 300 as described in FIG. 22, which also contains a tourniquet 310 which is similar to the tourniquet 110 as described with reference to FIGS. 2-16. The limb-cooling apparatus 200 will also be herein described in the context of a system 400 as described in FIG. 23, which contains a tourniquet 410, for example as described in FIG. 1, a limb-cooling apparatus 200, and a protecting system 490.

[0181] The limb-cooling apparatus 200 has an inner stretchable layer 210 configured to engage and/or contact a limb of a subject. In this embodiment, the inner layer 210 is made of a stretchable, elastic, fabric. Thus, the inner layer 210 is capable of snugly contacting a subject's limb and/or of ensuring a secure fit of the cooling apparatus 200 on the subject's limb.

[0182] Preferably, the inner layer 210 is also thermally conductive. By such provision the inner layer 210 is capable of effectively conducting heat away from a subject's limb so as to facilitate cooling.

[0183] In the present embodiment, the inner layer 210 is made from 130 g polyester-polyurethane copolymer marketed under the name UnderArmour (UnderArmour Europe B.V., Amsterdam, Netherlands).

[0184] The limb-cooling apparatus 200 also has an outer layer 220 at least partially attached to the inner layer 210.

[0185] The outer layer 220 preferably forms a thermally insulating layer. By such provision the cooling apparatus 200 may be capable of containing a cooling medium between the inner layer 210 and the outer layer 220, e.g. for an amount of time sufficient to allow cooling of the limb.

[0186] In the present embodiment, the outer layer was made from Shieldtex/780, a heat shield fabric made of a 20-micron aluminium foil impregnated with a black flame resistant polyurethane coating (Textile Technologies, Cheshire, UK).

[0187] The outer layer 220 and the inner layer 210 define a space 215 therebetween. As best shown in FIG. 17, the outer layer 220 and the inner layer 210 are attached at or near a peripheral region thereof so as to define a space 215 therebetween. The outer layer 220 and the inner layer 210 may be stitched, fused or otherwise bonded together.

[0188] In certain embodiments, the outer layer 220 and the inner layer 210 may be further attached in or more regions distal from the periphery of the outer layer and/or of the inner layer. For example, the outer layer 220 and the inner layer 210 may be attached in a longitudinal direction thereof so as to define a plurality of channels 217 between the inner layer 210 and the outer layer 220, as shown in FIG. 23. This may help a cooling medium 250 supplied to the channels 217 to remain within the channels 217, at least temporarily, thus providing effective cooling of the limb by avoiding the cooling medium to migrate to a localised area of the apparatus.

[0189] Advantageously, the inner layer 210 and the outer layer 220 are flexible, which allows the cooling apparatus 200 to be easily applied or affixed to the limb of a subject.

[0190] In the embodiments of FIGS. 17-22, the cooling apparatus 200 is provided as a sleeve which is configured to be wrapped onto a subject's limb. As shown in FIG. 22, there are provided Velcro fasteners 230 in the form of strips so as to secure the apparatus 200 on the subject's limb.

[0191] In other embodiments, the cooling apparatus 200 may be provided as a sock. In such instance the sock may be pulled onto a subject's limb. The sock may be secured to a subject's limb by the elastic nature of the inner layer itself, and/or by additional attachment means such as a band, strap, or the like.

[0192] The limb-cooling apparatus 200 also includes a cooling system 240 configured to supply a cooling medium 250 between the inner layer 210 and the outer layer 220.

[0193] The cooling medium 250 may be a gas or a gas mixture. In one embodiment, the cooling medium may be carbon dioxide. In another embodiment, the cooling medium may be a mixture of a gas and a coolant fluid, for example a mixture of a gas, e.g. compressed air, and a halogenated coolant, e.g. a perfluorocarbon such as perfluorohexane. The cooling medium 250 is stored and delivered from a canister 255, as shown in FIGS. 18 and 22.

[0194] The cooling system 240 comprises a delivery system 242 for the cooling medium 250. The delivery system 242 includes tubing 243 configured to deliver the cooling medium 250 in the space 215 between the inner layer 210 and the outer layer 220. Advantageously, the tubing 243 is a microporous tubing. By such provision, upon supply of a cooling medium 250 under pressure, the cooling medium 250 can permeate through the microporous material, thus expanding due to pressure difference and cooling as it expands. The tubing 243 is preferably made from a microporous polymer such as microporous ePTFE (expanded polytetrafluoroethylene). ePTFE may provide advantageous properties in terms of mechanical strength, resilience, flexibility, and porosity.

[0195] The delivery system 242, e.g. tubing 243, is connected to the container 255 configured to supply the cooling medium 250.

[0196] As explained above, the tubing 243 is provided between the first layer 210 and the second layer 220. As shown in FIG. 20, the tubing 243 may be attached to or secured to a support layer 245 configured to maintain the position and/or arrangement of the tubing 240, in use. The support layer 245 is flexible so as to maintain flexibility of the cooling apparatus 200. In the embodiment of FIG. 20, the support layer 245 is provided in the form of a mesh, which advantageously provides support to the tubing 240 without interfering with heat transfer and/or flow of the cooling medium 250 between the inner layer 210 and the outer layer 220.

[0197] Alternatively, as shown in FIG. 17, the tubing 243 may be attached and/or connected to strips 246 so as to maintain the arrangement, configuration, and/or position of the tubing 243 between the first layer 210 and the second layer 220.

[0198] As best shown in FIGS. 18 and 19, the cooling apparatus 200 includes a manifold 260 with an inlet 261 connected to the container 255, and multiple outlets 262 each connected to a respective outlet tube 263 to supply cooling medium 250 to the tubing 243. By such provision, cooling medium may be evenly supplied to the tubing 243 so as to permit even cooling of the space 215 between the inner layer 210 and the outer layer 220.

[0199] As best shown in FIG. 21, the apparatus 200 is also provided with one or more temperature indicators 270. The temperature indicator(s) 270 provide information about the temperature in at least a region of the cooling apparatus 200. In this embodiment, the temperature indicator 270 is attached to an outer surface of the outer layer 220. By such provision, a user may easily assess a change in temperature within the cooling apparatus 200, and may take appropriate action, e.g. inject more cooling medium 250 into, or release cooling medium 250 from, the cooling apparatus 200.

[0200] In this embodiment, the temperature indicator 270 is provided in the form of a temperature sensitive ink indicator within a film bonded or laminated, to the outer layer 220. In another embodiment, the temperature indicator(s) 270 may comprise temperature sensitive inks directly impregnated, dispersed within, coated on, or printed on the outer layer 220, e.g. on a surface thereof.

[0201] Advantageously, as shown in FIG. 22, the cooling apparatus 200 can be used in combination with the tourniquet 110 of FIGS. 2-16. By such provision, the entire system 300 may provide not only an improved means of reducing or preventing haemorrhage, and may also prolong tolerance to ischemia in the subject's limb by providing controlled hypothermia, thus improving the chance of full or partial recovery to the subject's limb.

[0202] In this embodiment, the tourniquet 110 and provided adjacent, and slightly overlapping, the cooling apparatus 200. It will be appreciated that, in other embodiments, the tourniquet 110 may be attached to each other, for example to reduce movement relative to each other and/or a patient's limb, for example by Velcro, clips, straps, rivets, etc.

[0203] Referring to FIG. 23, there is shown a tissue preservation system 400 according to an embodiment of the invention.

[0204] The tissue preservation system 400 includes a tourniquet 10 as described with reference to FIG. 1. It will be appreciated that the tourniquet used in the system 400, in other embodiments, may be a tourniquet 10 as described with reference to FIG. 1.

[0205] The system 400 also includes a cooling apparatus 200 as described with reference to FIGS. 17-21.

[0206] The system also includes a limb-protecting apparatus 480 which has a flexible, gas-impermeable, material 482 capable of containing a subject's limb, in this embodiment, a leg. The limb-protecting apparatus 480 also has a means 484 for injecting a gas inside the material 482, which in this embodiment is the foot pump which is also used to inflate the tourniquet 10.

[0207] The material 482 is made of a flexible transparent membrane which can be inflated and is sufficient strong and resilient to protect the limb, and also allows a user, e.g. an attendant or clinician, to see the subject's limb.

[0208] The limb-protecting apparatus 480 is attachable to the tourniquet 10, which allows the various elements 10,200,480 to be used as a entire or integrated system 400. By such provision, the entire system 400 may provide not only an improved means of reducing or preventing haemorrhage, and/or may prolong tolerance to ischemia in the subject's limb by providing controlled hypothermia, but may also protect the limb after application of the tourniquet 10 and/or during hypothermic control of the limb.

[0209] In other embodiments, the limb-protecting apparatus 480 may be attached to the limb cooling apparatus 200 rather than, or in addition to, the tourniquet 10.

[0210] The limb-protecting apparatus 480 also has an inlet valve or port 486 to allow a tube 256 connected to the canister 255 to pass through the limb-protecting apparatus 480 and connect to the cooling system 240 of the limb-cooling apparatus 200. The limb-protecting apparatus 480 also has an outlet valve or port 487 to allow a tube 257 to release cooling medium from the limb-cooling apparatus 200 when required.

[0211] 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.