TOURNIQUET

Abstract: A tourniquet (10) having a body part engaging formation (11) adapted to engage a part of a patient's body, and a handle formation (12) integral with or attached to the engaging formation to enable the tourniquet (10) to be applied to the patient's body part.

Description: Title: Tourniquet Description of Invention This invention relates to a tourniquet. The invention relates particularly but not exclusively to a digit tourniquet for use in surgery to the fingers, but it will be appreciated that the device could equally be used in surgery to other body parts, such as toes, or during penile surgery. For the sake of convenience, however, the term 'Digit Tourniquet' shall henceforth be used in the description. The provision of a convenient and high quality tourniquet for use in finger and other types of surgery has long presented difficulties. Ideally, surgery to a digit should be carried out in a clear bloodless region, with little or no ischaemia being caused at that region, or in surrounding tissues. The lack of a versatile and high quality digit tourniquet, which is easy to use, has long presented surgeons in orthopaedics and accident and emergency plastic surgery with a considerable problem, when dealing with fmger surgery. As a result, it has become common practice to stop blood flow further up a patient's arm, by the use, for example, of a pneumatic tourniquet of the type commonly used to take a patient's blood pressure. However, this has its drawbacks in that it may cause ischaemia to tissues over a wider area, remote from the field of surgery, and also parasthaesia or paralysis. Moreover, accurate control of blood flow in a patient's finger is difficult to achieve in this way. Techniques adapted specifically for use with a finger include the application of drain tubings such as catheters, or pearl rose drains clipped around the fingers by the use of forceps. However, these exert an uneven, and relatively high pressure (όOOrnmHg - 800mmHg) around the finger and have resulted in neurovascular damage and tissue necrosis. A further alternative has been the use of a finger glove tourniquet fashioned from cut rubber gloves, but these also have the disadvantage of exerting great pressure to the digit (150mmHg - 500mmHg) and increase the risk of necrosis to the surrounding tissue. Worse still, such fmger glove tourniquets have been known to result in the loss of a digit as a result of severe ischaemia, when the tourniquet has been forgotten about, and left on the digit concerned. This problem is exacerbated by the similar colours of the glove tourniquet and an exsanguinated fmger. It is therefore an object of the present invention to provide an improved digit tourniquet which at least reduces some of the problems outlined above. According to one aspect of the present invention, I provide a tourniquet having a body part engaging formation adapted to engage a part of a patient's body, and a handle formation integral with or attached to the engaging formation to enable the tourniquet to be applied to the patient's body part. The tourniquet is preferably configured for engagement with a patient's digit. The digit engaging formation may be generally ring-like so that it may be received slidably about the patient's digit. The handle formation may comprise a generally elongate member integral or attached to the ring, and preferably, is generally rigid. In this way, the tourniquet may be applied easily to the patient's digit by a doctor, who may hold and manipulate the tourniquet using the elongate handle. The digit engaging formation may also be generally rigid, but preferably is somewhat flexible. Conveniently, the engaging formation may consist of or comprise one or more inflatable chambers, such that the configuration of an inner surface thereof (i.e., that surface which engages the patient's digit) may conform to the shape of the patient's digit. In this way, application of uneven, and hence potentially harmful, pressure to a patient's digit may be avoided. The handle formation may comprise means to add gas to or remove gas from the inflatable chamber. Conveniently, the gas used is air, although it is envisaged that other non- harmful gases could also be used. The gas supply means may comprise a passage extending through the handle formation from a distal end thereof, to which may be attached an automatic pump, or other pneumatic device such as a syringe. The tourniquet may further comprise a gas pressure monitoring device, to enable a user of the tourniquet to ensure that unduly high pressure is not applied to the patient's digit. There may also be provided a safety device such as a pressure relief valve, operative to allow or cause gas to exit the inflatable chamber in the event that the pressure of gas in the chamber exceeds a certain limit. The digit tourniquet preferably also comprises indicator means attached thereto or integral therewith to serve as a reminder of the presence of the tourniquet on the patient's finger. In this way, the risk of ischaemia developing is considerably reduced. The indicator means may comprise a tag, label, or the colour of the tourniquet itself. Preferably, however, the indicator means comprises a tab on which information may be written. Such information may indicate a maximum safe time period for which the tourniquet should be applied. The tourniquet may also comprise quick release means, whereby the tourniquet may be removed rapidly from a patient's digit, in case of emergency. The quick release means may comprise a release member, a part of which, during normal use of the tourniquet, is positioned within the engaging formation, and another part of which is disposed outside of the tourniquet. The release member may comprise a cord, wire, thread or the like, one end of which is anchored securely within the engaging formation, and another end of which protrudes from an end of the handle formation. In the event of an emergency arising, the user of the tourniquet may grasp the remote end of the release member, and pull the release member away from the tourniquet. In this way, removal of the release member may cause a split or tear to occur in an outer surface of the tourniquet, thus weakening its structure, and enabling rapid removal of the tourniquet from the patient's fmger. It is envisaged that a variety of differently sized tourniquets may be provided. The internal diameter of the engaging formation of the largest tourniquet of the range is preferably about 30mm or so, which corresponds to the maximum likely diameter of a person's fmger. However, as indicated above, the tourniquet may be useful in medical applications outside the field of digit surgery, such as penile operations, or congenital reconstruction. Thus, larger sizes of tourniquet may be appropriate in some circumstances. Clearly, in order that the tourniquet may apply the correct pressure to a person's digit, it is important that the size of the engaging formation be chosen carefully. According to a second aspect of the present invention, I provide a sizing device for determining the actual or relative sizes of a person's fingers, comprising a finger engaging portion defining an aperture, wherein the dimensions of the aperture are variable, and wherein indicating means is provided to enable a person's finger size to be determined. The fmger engaging portion may be generally circular, and may comprise a split ring, partly covering a movable member located therewithin. According to a third aspect of the present invention, there is provided a method of exsanguinating or substantially exsanguinating a person's digit, comprising procuring a tourniquet having a digit engaging portion, bringing the engaging formation into contact with the end of the person's digit, positioning the engaging formation such that it extends at least partly around the person's digit, and sliding the engaging formation down the length of the person's fmger, characterised in that throughout the sliding movement, inward pressure on the patient's finger is exerted by said engaging formation, as a result of which that part of the finger disposed between the end thereof and the engaging formation, becomes exsanguinated or substantially exsanguinated. Preferably, the method involves the use of a digit tourniquet described in one or more of the preceding paragraphs. The invention will now be described in greater detail, but by way of example only, by reference to the accompanying drawings wherein FIGURE 1 is a perspective view of one embodiment of the present invention, insofar as it relates to a digit tourniquet. FIGURE 2 shows an alternative embodiment; FIGURE 3 illustrates a digit sizer in accordance with the present invention, for use with a person's right hand; and FIGURE 4 illustrates a similar device to that shown in Figure 3, but which is adapted for use with a person's left hand. Referring first to Figure 1, a digit tourniquet 10 is shown having a digit engaging formation 11, part of which in this example comprises an inflatable ring. The ring 11 is attached to a handle 12, which contains one or more passages whereby gas such as air may be introduced to or removed from the ring 11, by use of a pneumatic pump such as a syringe 13. The ring 11 and handle 12 may have a generally rigid outer surface, to contain an inner inflatable tube 13, which, when inflated, protrudes from the ring 11 through an aperture 14 therein, in much the same way as a bicycle inner tube protrudes from a bicycle tyre. The tourniquet is provided with a pressure monitoring device 15, to indicate to a user of the device the gas pressure within the tourniquet, so that the application of excess pressure to a person's digit may be avoided. The pressure reading device 15 may incorporate a pressure release valve, which is operative to enable or cause gas to be vented from the tourniquet in the event that a dangerously high pressure is detected. The release of excess gas may be through a vent 16. There may alternatively or additionally be provided an emergency outlet 17, conveniently disposed at a distal end of the handle 12. In normal use, the outlet 17 is closed by a cap 18, but the cap 18 is preferably sufficiently weak to enable it to be broken by application of fmger pressure by a user of the tourniquet. Thus, if it becomes necessary to reduce the pressure within the tourniquet rapidly, breakage of the cap 18 enables the gas to be withdrawn quickly. There is also provided an indicator tab 19, conveniently attached to the handle 12, on which information such as the length of time for which the tourniquet should be applied, may be inscribed. At least the tab 19 should be brightly coloured, to make the tourniquet eye-catching, and thus to reduce the possibility of the tourniquet being left around a patient's finger, which could result in ischaemia or tissue necrosis. Gas may be applied to the tourniquet through a tube 20, one end of which is attached to the distal end of the handle, and the other end of which is attached to the outlet 21 of the syringe 13. There may be provided a cap 22, to close the remote end of the tube 20, and thus to prevent undue escape of gas. The handle and/or outer surface of the ring 11 may be formed from a plastics material, or a softer material such as latex rubber. Referring now to Figure 2, an alternative construction is shown, in which the ring 11 and the handle 12 are formed from a generally solid material, without the need for an internal inflatable chamber. Located within the handle 12 and the ring 11 is an emergency removal device 23 in the form of a wire, extending from one end of the handle 12, to, and extending partly within, the ring 11. In the event that it becomes necessary to remove the tourniquet quickly from a person's finger, a user of the tourniquet may grasp the remote end of the removal device, and pull it shaφly upwards in the direction indicated by arrow A. The other end, indicated generally at 23a is anchored firmly within the ring 11, such that pulling on the wire 23 causes a tear or split to occur in an outer surface of the handle and ring. This weakens the structure of the tourniquet, and enables it to be removed from a person's digit more readily. Referring now to Figures 3 and 4, right/left handed finger sizers are shown. For the sake of convenience, only Figure 3 will be described in detail as it will be appreciated that the arrangement in Figure 4 is to all intents and purposes identical, albeit of different handedness. The device comprises a housing 30 within which are located three finger engaging formations 31, 32 and 33, each of which is provided by two part- circular sleeves 34, secured to a base 35 of the device, and in which a slidable insert 36 is received. In use, a person introduces his/her thumb into the aperture within the device 31, his/her first, second or third finger within the device 32, and his/her little fmger in the device 33. The hollow parts 34 are then caused to move towards each other, such that the slidable insert 36 is received further into one or both of the hollow parts 34. It is envisaged that at least a section 37 of each device may be transparent or translucent, and may be provided with gradations 38, such that movement of the insert may be visible through the parts 34. By appropriate calibration of the gradations 38, the correct size of tourniquet may then be selected for the person concerned, thus ensuring that in use, the tourniquet will apply the correct pressure to the person's digit, thus enabling the tourniquet to function efficiently, but without risk of causing harm to the patient. In use, the sizing device is used to select a correctly sized tourniquet, which will fit relatively tightly around a patient's finger (when inflated, if appropriate). The tourniquet is then slid along the length of the patient's finger, and in doing so, 'squeezes' blood out of the fmger in a peristaltic manner. It will be appreciated, however, that in view of the configuration of the ring of the tourniquet, even pressure is applied about the finger, and that in the case of the inflatable embodiment, the pressure exerted may be varied as required. Once the desired surgical operation is complete, the pressure may be released, and the tourniquet removed by sliding movement in the opposite direction. In the case of the non-inflatable version, it may be removed by use of the release cord. Finally, for the avoidance of any doubt, it will be appreciated that the term 'tourniquet' is used herein to relate to any surgical or medical device which is able to reduce, or cease, the flow of blood at a particular point on a person's body. The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims: CLAIMS 1. A tourniquet having a body part engaging formation adapted to engage a part of a patient's body, and a handle formation integral with or attached to the engaging formation to enable the tourniquet to be applied to the patient's body part. 2. A tourniquet according to Claim 1 which is configured for engagement with a person's digit. 3. A tourniquet according to Claim 1 or Claim 2 wherein the engaging formation is generally ring-like. 4. A tourniquet according to Claim 1 or Claim 2, or Claim 3 wherein the handle formation is generally elongate, and generally rigid. 5. A tourniquet according to any one of the preceding claims wherein the engaging formation consists of or comprises one or more inflatable chambers. 6. A tourniquet according to Claim 5 wherein the handle formation comprises means to add gas to or remove gas from the inflatable chamber. 7. A tourniquet according to Claim 6 wherein the gas supply means comprises a passage extending through the handle formation from a distal end thereof. 8. A tourniquet according to Claim 7 wherein there is provided an automatic pump or other pneumatic device associated with the passage. 9. A tourniquet according to any one of the preceding claims further comprising a gas pressure monitoring device. 10. A tourniquet according to any one of the preceding claims further comprising a pressure relief valve. 11. A tourniquet according to any one of the preceding claims further comprising indicator means to serve as a reminder of the presence of the tourniquet on a patient's body part. 12. A tourniquet according to Claim 11 wherein the indicator means comprises a brightly coloured tab or label. 13. A tourniquet according to any one of the preceding claims further comprising quick release means. 14. A tourniquet according to Claim 13 wherein the quick release means comprises a release member, a part of which, during normal use of the tourniquet, is positioned within the engaging formation, and another part of which is disposed outside of the tourniquet. 15. A tourniquet according to Claim 14 wherein the release member comprises a cord, wire or thread. 16. A tourniquet according to Claim 14 or Claim 15 wherein one end of the release member is anchored securely within the engaging formation, and another end of which protrudes from an end of the handle formation. 17. A sizing device for determining the actual or relative sizes of a person's fingers, comprising a finger engaging portion defining an aperture, wherein the dimensions of the aperture are variable, and wherein indicating means is provided to enable a person's finger size to be determined. 18. A sizing device according to Claim 17 wherein the finger engaging portion comprises a split ring, partly covering a movable member located therewithin. 19. A device for exsanguinating or substantially exsanguinating a person's body part, comprising a body part engaging formation, which is brought into contact with the end of the person's body part, positioned such that it extends at least partly around the person's body part, and slid down the length of the person's body part, whereby throughout the sliding movement, inward pressure on the patient's body part is exerted by said engaging formation, as a result of which that part of the body disposed between the end thereof and the engaging formation, becomes exsanguinated or substantially exsanguinated. 20. A device according to Claim 19 also being in accordance with any one of Claims 1 to 16. 21. A tourniquet substantially as hereinbefore described and/or as shown in the accompanying drawings. 22. A sizing device substantially as hereinbefore described and/or as shown in the accompanying drawings.

Inventors: CHUKWULOBELU ROSEMARY, CHUKWULOBELU, ROSEMARY
Applicants: BIBBY STERILIN LTD, CHUKWULOBELU ROSEMARY, BIBBY STERILIN LIMITED, CHUKWULOBELU, ROSEMARY
Application year: 1999
Main classification: A61B17
IPC codes: A61B17, G01B3