An apparatus for applying pressure to an abdominal aorta

Abstract

An apparatus configured to apply pressure to the abdominal aorta of a patient comprising: a plunger having a first end for contacting a patient and applying pressure to the abdominal aorta of the patient; a counter pressure part configured to contact a support surface; and an intermediate member having a first end and an opposite second end wherein the intermediate member is coupled to: the plunger at the first end of the intermediate member; and the counter pressure part at the second end of the intermediate member; and wherein the plunger is movable towards and away from a patient and wherein the apparatus is configured such that the position of the plunger is fixable such that applied pressure is maintained, the apparatus further comprising a pressure indicator configured to provide an indication that a target pressure has been applied by the plunger.

Description

[0001]AN APPARATUS FOR APPLYING PRESSURE TO AN ABDOMINAL AORTA Field The present disclosure relates to an apparatus configured to apply pressure to the abdominal aorta of a patient. The present disclosure further relates to a method for applying pressure to the abdominal aorta of a patient using the apparatus. Background Excessive bleeding is a problem as old as humanity. More particularly, post- partum haemorrhage poses risks to women around the world. Temporary haemostasis (restriction or stopping of blood-flow to the uterus) can be achieved by way of compression of the abdominal aorta. This is an intervention that is recommended in current practice and can be achieved manually by using the fist of the medical practitioner to externally compress the aorta underlying the naval region of the patient. However, this procedure is underused and may not be reliable due to the education and skills of the practitioner. Further, performing manual aortic compression during patient transportation, such as from a childbirth room to an operating theatre or even between hospitals may be ineffective and hazardous both to the practitioner and the patient. The use of tourniquets (i.e. circumferent devices used for compression of an underlying blood-vessel by means of squeezing the surrounding tissues of a body-region) is a recommended procedure in traumatic bleeding and some devices have also been proposed for use to compress the abdominal aorta. However, tourniquet-like devices used on the abdomen typically exert pressure that may lead to intolerable side effects. Summary According to a first aspect of the present disclosure, there is provided an apparatus configured to apply pressure to the abdominal aorta of a patient, the apparatus comprising: a plunger having a first end for contacting a patient and applying pressure to the abdominal aorta of the patient; a counter pressure part configured to contact a support surface; and an intermediate member having a first end and an opposite second end wherein the intermediate member is coupled to: the plunger at the first end of the intermediate member; and the counter pressure part at the second end of the intermediate member; and wherein the plunger is movable towards and away from a patient in order to respectively apply pressure to and relieve pressure from the abdominal aorta of the patient and wherein the apparatus is configured such that the position of the plunger is fixable such that pressure applied to the patient is maintained, the apparatus further comprising a pressure indicator configured to provide an indication that a target pressure has been applied by the plunger. In one or more embodiments, the plunger may be moveable in a pressure application axis linearly towards and away from the patient in order to apply pressure to and relieve pressure from the abdominal aorta of the patient. In one or more embodiments, the apparatus may further comprise a pressure maintenance mechanism configured to maintain the target pressure applied by the plunger in response to movement of the patient relative to a fixed position of the plunger. In one or more embodiments, the pressure maintenance mechanism may resiliently bias the plunger, once fixed, to maintain the pressure applied by the plunger in response to movement of the patient relative to the fixed position of the plunger such that, in response to movement of the patient, the plunger automatically adapts its position to maintain the pressure set by the fixed position of the plunger. In one or more embodiments, the plunger may be repositionable in a plane of the pressure application axis so that the plunger can be aligned with the naval of the patient. In one or more embodiments, the apparatus may be configured such that the plunger is moveable out of the pressure application axis in order to provide a space for the patient to be positioned in the pressure application axis. In one or more embodiments, the intermediate member may comprise a first sub member comprising the first end of the intermediate member and a second sub member comprising the second end of the intermediate member wherein the first and second sub members are hingably coupled and wherein hingably moving the first sub member relative to the second sub member causes the plunger to be moved out of the pressure application axis. In one or more embodiments, the apparatus may further comprise a coupling mechanism configured to provide for coupling and decoupling of the plunger from the intermediate member. In one or more embodiments, the counter pressure part may comprises a back- plate configured to be placed under the back of a patient. In one or more embodiments, the back plate may comprise a first panel having a first major surface and a second panel having a first major surface and wherein the first panel and the second panel are foldable between: an open position for positioning the back-plate under the back of a patient such that the first major surface of the first panel and the first major surface of the second panel can be placed in contact with the back of the patient; and a closed position wherein the first major surface of the first panel faces the first major surface of the second panel. In one or more embodiments, the first end of the plunger may comprise a concave surface arranged for at least partially contacting and wrapping around a portion of a vertebral column of the patient. In one or more embodiments, the first end of the plunger may comprise a resiliently deformable material configured to resiliently deform when pressure is applied to a patient. In one or more embodiments, the plunger may comprise a coarse movement mechanism and a fine movement mechanism wherein the coarse movement mechanism is configured to provide for movement of the coarse movement of the plunger in the pressure application axis and the fine movement mechanism is configured to provide for fine movement of the plunger in the pressure application axis. In one or more embodiments, the intermediate member may be a rigid member. In one or more embodiments, the intermediate member may have a curved profile. In one or more embodiments, the intermediate member comprises a rigid member having a profile to define a void between the plunger and the counter pressure part, at least when the plunger is withdrawn away from the patient. In one or more embodiments, the intermediate member has a C- shaped profile. In one or more embodiments, the intermediate member has a profile configured such that the patient is received in a void between the plunger and the counter pressure part and the apparatus extends around a side of the patient and the plunger is supported above the patient and positioned substantially over the abdominal aorta. Thus, with such an intermediate member, the plunger may be cantilevered allowing for straightforward positioning of the apparatus relative to the patient. According to a second aspect of the present disclosure, there is provided a method of using the apparatus of the first aspect, the method comprising: receiving a patient between the plunger and the support surface such that the naval of the patient is substantially in line with the pressure application axis; moving the plunger towards the patient in order to apply the target pressure to the patient; and fixing the plunger such that pressure applied to the patient is maintained. While the disclosure is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that other embodiments, beyond the particular embodiments described, are possible as well. All modifications, equivalents, and alternative embodiments falling within the spirit and scope of the appended claims are covered as well. The above discussion is not intended to represent every example embodiment or every implementation within the scope of the current or future Claim sets. The figures and Detailed Description that follow also exemplify various example embodiments. Various example embodiments may be more completely understood in consideration of the following Detailed Description in connection with the accompanying Drawings. Brief Description of the Drawings One or more embodiments will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 shows a perspective view of example embodiment of an apparatus of the present disclosure; Figure 2 shows a side view of the apparatus of figure 1; Figure 3 shows a perspective view of the apparatus of figure 1 with an exploded view of the plunger; Figure 4 shows a cross-sectional view of an example embodiment of a plunger of the present disclosure; and Figure 5 shows an example method of operating the apparatus according to the present disclosure. Detailed Description The present disclosure provides an apparatus which is configured to apply pressure to the abdominal aorta of a patient. In particular, the apparatus is configured to apply a consistent pressure to the abdominal aorta by providing for a plunger which is moveable towards and away from the patient in such a manner as to not provide for circumferent (meaning only applying pressure in the midline without any additional lateral or vertical constriction of the abdomen and its organs) constriction of the patient. By applying pressure to the abdominal aorta, it is possible to induce haemostasis, thereby restricting or entirely preventing blood flow through the abdominal aorta. In the following description, reference will be made to two persons: a user and a patient. While the presence of the user and patient are not essential elements of the invention itself, it may be helpful to describe certain features with reference to one or both of these persons. In the context of the following disclosure, the patient is the person to whom pressure is to be applied. The patient can situate themselves, or be situated by another person, with their body between a plunger of the apparatus and a support surface such that the plunger can be moved to apply pressure to the abdominal aorta. It may be helpful to describe that the plunger moves towards or away from the patient, however, it will be appreciated that this movement may alternatively be described as vertical movement of the plunger in an upwards or downwards direction or as movement towards or away from the support surface on which the patient is to be placed in-use. The support surface, in this disclosure, is a surface on which the patient may be disposed. For example, the support surface may be an operating table, a hospital bed or another suitable surface. In the context of the following disclosure, the user is the person who is manipulating the apparatus in order to apply the pressure to the patient. For example, the user may be a medical practitioner such as a medical doctor. In other embodiments, the device may be manipulated automatically or robotically. In such embodiments, the user may be the automated system or robot which is manipulating the apparatus in order to apply the pressure, although such an automated system or robot may ultimately be controlled or directed by a remote user interacting with an input terminal. Figures 1 and 2 show an example embodiment of an apparatus 100 according to the present disclosure in a perspective view and side view, respectively. The apparatus 100 comprises a plunger 101 for applying pressure to the abdominal aorta of a patient; a counter pressure 102 part configured to contact a support surface and an intermediate member 103 which connects the plunger 101 and the counter pressure part 102. The plunger 101 is moveable towards and away from the patient in order to respectively apply pressure to and relieve pressure from the abdominal aorta of the patient. Further, the apparatus 100 is configured such that the position of the plunger 101 is fixable such that pressure applied to the patient is maintained. The apparatus 100 finally comprises a pressure indicator (not shown) configured to provide an indication that a target pressure has been applied by the plunger 101. The apparatus 100 is configured to contact the exterior of the patient, preferably around the naval. Pressure is applied to the abdominal aorta via the rest of the body. When used on a woman post-partum, the abdominal wall is still in an altered arrangement from the pregnancy (separation of the ligament connecting the rectus abdominal muscles). Due to the separation of the abdominal wall, the pressure is able to be applied to the abdominal aorta without significantly impacting the abdominal organs and exert pressure towards the diaphragm. Due to the rearrangement of the internal organs, the pressure is able to be applied to the abdominal aorta without significantly impacting the internal organs. Figure 3 shows the example embodiment of figures 1 and 2 with an exploded view of the plunger 101. Figure 4 shows a cross-sectional view of the plunger 101. Both figures 3 and 4 will be referred to in the following description of the plunger 101. The plunger 101 comprises a rigid member which may be a single member or may be comprised of a plurality of parts. In a most simple embodiment, the plunger 101 may be a single elongate member such as a rod which comprises a first end 102 which is for applying pressure to the abdominal aorta of the patient. The plunger 101 may further comprise a second end 103 opposite the first end 102. The plunger 101 is moveable towards and away from the patient in order to respectively apply pressure to and relieve pressure from the abdominal aorta of the patient. In one or more embodiments, the movement of the plunger 101 may be described as being moveable in a pressure application axis 104 linearly towards and away from the patient in order to apply pressure to and relieve pressure from the abdominal aorta of the patient. The pressure application axis 104 is illustrated in figure 2 and defines a linear axis through the centre of the plunger 101. For the purposes of illustration, figures 1 and 2 show example co-ordinate axes. It can be seen that the elongate plunger 101 extends in the z-direction and that the pressure application axis 104 also extends in the z-direction. A plane of the pressure application axis may also be defined as the x-y plane through which the pressure application axis 104 extends. While the plunger 101 may be linearly moveable in one or more embodiments, it will be appreciated that non-linear movement of the plunger 101 may be possible if such movement is still able to contact and apply a consistent pressure to the abdominal aorta of the patient. In one or more embodiments wherein perfectly linear movement is not used, the movement of the plunger 101 may still be substantially linear at the point of contacting the abdominal aorta via the patient’s body. For example, a large-enough arc of movement may provide substantially linear movement through at least a portion of the arc which is sufficiently linear to apply the desired pressure to the abdominal aorta without applying lateral pressure to the patient. The plunger 101 may comprise one or both of a coarse movement mechanism (not shown) and a fine movement mechanism 105. The coarse movement mechanism may be configured to provide for coarse movement of the plunger 101 in the pressure application axis 104. The fine movement mechanism 105 may be configured to provide for fine movement of the plunger 101 in the pressure application axis 104. The movement provided for by the fine movement mechanism 105 may be more precise or more controlled than the movement provided by the coarse movement mechanism. In one or more embodiments, the coarse movement mechanism may allow for movement of the plunger 101 in the pressure application axis 104 by way of the application of linear force along the pressure application axis 104. For example, the coarse movement mechanism may allow for the user to push the plunger 101 downwards or lift the plunger 101 upwards. Such coarse movements may be larger and quicker than those associated with the fine movement mechanism 105. For example, the coarse movement mechanism may comprise a latch that allows for the release and manual vertical movement of the plunger. The latch may subsequently be closeable so that further coarse movement of the plunger 101 is prevented. The plunger 101 may further have a linear groove 106 in its outer body 107 which facilitates the linear movement of the plunger 101 while preventing or restricting rotational movement of the plunger 101. The linear groove 106 may be a guide groove and may engage with a portion of the intermediate member 111. In other embodiments, the coarse movement mechanism may comprise a ratchet mechanism wherein the teeth of the coarse movement ratchet are spaced sufficiently apart that large movements of the plunger 101 can be made quickly and easily by the user. In one or more embodiments, the fine movement mechanism 105 may allow for movement of the plunger 101 in the pressure application axis by way one or more of: rotational movement of the plunger 101; rotational movement of a part of the plunger 101; rotational movement of a screw-threaded coupling device 108; ratcheted movement or another approach. Rotational movement of the plunger may involve the rotation of the plunger 101 through a screw-threaded mechanism. For example, the exterior of the plunger 101 may comprise a screw-thread and the plunger 101 may be coupled to the intermediate member 111, at least in part, by way of a corresponding screw-threaded coupling 108 device such that rotation of the plunger 101 causes the plunger 101 to be moved linearly in the pressure-application axis 104. In embodiments wherein a portion of the plunger 101 comprises a screw- thread, a portion of the body of the plunger may comprise a screw-thread 109 such that rotation of the screw-threaded body portion 109 provides for linear motion of the plunger 101. In such an embodiment, the first end 102 of the plunger 101 may be rotationally isolated from the screw-threaded body portion 109 such that rotation of the screw-threaded body portion 109 does not cause rotation of the first end 102 of the plunger 101. The use of a screw-thread- based mechanism may be particularly advantageous, as it provides for an easy method to carefully and steadily adjust the pressure applied by the plunger 101 while not uncomfortably rotating the portion of the plunger 101 which is in contact with the patient. It will be appreciated that rotational isolation of the first end 102 of the plunger 101 may be achieved in many different ways. In yet other embodiments, the plunger 101 may comprise a screw-threaded body portion 109 and may be coupled to the intermediate member 111 by a corresponding screw-threaded coupling device 108, such as the embodiment shown in figures 1 – 4. The screw-threaded coupling device 108 may comprise an adjustment ring 108 that comprises the corresponding screw-thread on its inner surface. The adjustment ring 108 may be configured to be rotated by the user wherein rotation of the adjustment ring 108 causes linear movement of the plunger 101 through the adjustment ring 108 due to the interoperation of the coupled screw-threaded portions. In embodiments wherein the fine movement mechanism 105 comprises a ratcheted movement mechanism, the entire plunger 101 may move as a result of adjusting the ratchet or a portion of the plunger 101 may extend based on adjustment of the ratchet. For example, the first end of the plunger 101 may be able to be moved relative to an outer body 107 of the plunger 101 by way of a ratchet mechanism. In embodiments wherein the coarse movement mechanism and the fine movement mechanism 105 comprise ratchet mechanisms, the spacing of the teeth of the fine movement ratchet may be spaced closer together than the teeth of the coarse movement ratchet such that movement using the fine movement ratchet provides smaller movement increments than that provided by the coarse movement ratchet. While a discussion is provided above of different movement mechanisms that may be employed in embodiments comprising both a coarse movement mechanism and a fine movement mechanism, it will be appreciated that any one of these mechanisms may be used in embodiments that only comprise a single way of moving the plunger 101. That is, in some embodiments, movement of the plunger may only be provided for by way of linear movement of the plunger 101 by opening a latch, moving the plunger 101, and subsequently moving the latch. Alternatively, movement of the plunger 101 may only be provided for by way of a screw-threaded mechanism. The position of the plunger 101 is fixable such that pressure applied to the patient is maintained. In embodiments wherein movement is provided by way of a ratchet or screw-thread, the fixability of the position of the plunger 101 may be inherent in the nature of the movement mechanism. That is, when a user stops adjusting a screw-threaded mechanism or a ratcheted mechanism, the user may need to take no additional action in order for the position of the plunger 101 to be fixed. In other embodiments, such as those wherein the plunger 101 is physically pushed down or pulled up by the user, the position of the plunger 101 may be fixable by way of closing a securing latch or by engaging another suitable fixing apparatus in order to prevent the plunger 101 from being unintentionally moved, thereby allowing for the maintenance of a pressure applied to the patient. It will be appreciated that a very wide range of possible fixing mechanisms (inherent, or additional) may be used in order to provide for the fixable nature of the position of the plunger 101 and that these may vary significantly depending on the method selected for moving the plunger 101. The apparatus 101 may further be configured such that the plunger 101 is repositionable in a plane of the pressure application axis 104 such that the plunger 101 can be aligned with the naval of the patient. That is, referring to figures 1 and 2, the apparatus 100 may be repositionable in the x-y plane in order to allow for the plunger 101 to be accurately positioned over the patient’s naval. This may remove the need for a patient’s naval to be perfectly placed under the plunger 101. Instead, the patient may be placed in an approximately correct position and the exact positioning of the plunger 101 may be adjusted in order to provide for accurate application of the plunger 101 to the patient. In some instances, it may be significantly easier and even safer to move the plunger 101 into the correct position in the plane of the pressure application axis than to attempt to reposition the patient. The repositionability of the plunger 101 may be due to the plunger 101 being able to be moved relative to the intermediate member or the intermediate member itself may be configured to be moveable in the plane of the pressure application axis 104 in order to provide for the repositioning of the plunger 101. In one or more embodiments, a portion of the intermediate member 111 may be moveable or extendable in order to provide for the repositionability of the plunger 101. The plunger 101 may be repositionable in a single direction in the plane of the pressure application axis 104 or it may be repositionable in the whole two-dimensional plane. Movement of the plunger 101 in the plane of the pressure application axis 104 may be provided for by way of an in-plane adjustment mechanism. It will be appreciated that a wide range of potential in-plane adjustment mechanisms may be used in order to provide for the in- plane movement of the plunger 101. For example, in-plane movement may be provided by one or more of the intermediate member 111 being moveable relative to the counter pressure part or by the plunger 101 being moveable relative to the intermediate member 111. The exact mechanisms that provide for these relative movement may be provided in a plurality of different ways and so these will not be expanded on further here. The second end 103 of the plunger 101 may comprise a handle which is shaped to be suitable for a user to one or both of grip and move downwards or to place their hand on top of and push vertically downwards. For example, the second end 103 may have a substantially flat or slightly rounded end such that pressing downwards onto the second end 103 in order to move the plunger 101 down is comfortable. The body of the second end of the plunger 101 may comprise one or more lips or ridges which provide for assistance to a user who wishes to grip the second end 103 of the plunger 101 around the curved body. The first end 102 of the plunger 101 may be rigid. The first end 102 of the plunger 101 may comprise a concave surface arranged for at least partially contacting and wrapping around a portion of a vertebral column of the patient. More specifically, the first end 102 of the plunger 101 may be shaped as a concave channel that is sized to contact and partially extend around the vertebral column of a patient. The concave surface of the first end 102 of the plunger 101 may further be arranged such that it aligns with the positioning of the vertebral column of the patient when the patient is properly located beneath the plunger 101. Arranging the first end 102 of the plunger 101 may require orienting the concave channel such that it aligns with the vertebral column. By providing a concave surface, such as a concave channel, it can be ensured that the abdominal aorta is contacted by the first end 102 of the plunger 101 whether the aorta is positioned immediately superior or slightly laterally to the convex shape of the underlying vertebrae. Pressure can then be applied to the abdominal aorta between the first end 102 of the plunger 101 and the vertebral column of the patient. In one or more embodiments, the first end 102 of the plunger 101 may comprise a resiliently deformable material configured to resiliently deform when pressure is applied to it, such as when pressure is applied by its pressing against a patient. The resiliently deformable material may be configured to return to its original shape upon the removal of the pressure. For example, the resiliently deformable material may be a gel material configured to resiliently deform when pressure is applied to it. By providing a resiliently deformable material, the resiliently deformable material may be able to shape itself around the vertebral column, or any other part of the patient’s body, as pressure is applied by the movement of the plunger 101. In a similar manner to that described with respect to the concave channel, using a resiliently deformable material such as a gel can ensure that the abdominal aorta is contacted by the first end of the plunger 101 and that pressure can be applied to the resiliently deformable material between the first end of the plunger 101 and the vertebral column of the patient. It will be appreciated that, in one or more embodiments, the first end 102 of the plunger 101 may both comprise a concave shape, such as a concave channel, and a resiliently deformable material. That is, the concave shape of the first end 102 of the plunger 101 may be formed of the resiliently deformable material. In such embodiments, the first end 102 of the plunger 101 may comprise, in an unpressured state, a resiliently deformable concave shape, such as a resiliently deformable concave channel. The resiliently deformable shape may then be able to deform upon the application of pressure thereto. This may beneficially allow the shape of the first end of the plunger 101 to be predisposed in a shape which will easily press against the vertebral column, with the abdominal aorta between, and to then further adjust its shape as pressure is applied. It will be appreciated that the main body of the plunger 101 may comprise a rigid material and that the resiliently deformable material may be coupled to the rigid main body. In such embodiments, the first end of the main body of the plunger 101 which contacts the resiliently deformable material may be concave. In such embodiments, the resiliently deformable material may also be concave, as already described, or it may be convex in shape. Providing a convex resiliently deformable material mounted to a concave first end of the main body of the plunger 101 may be beneficial for splitting the abdominal wall layers under the skin as it is lowered onto and against the patient. The convex resiliently deformable material may co-operate with the concave surface of the main body of the first end of the plunger 101 to distribute the gel material towards the sides and thereby provide for improved contact with the patient. The plunger 101 may further comprise a pressure maintenance mechanism 110 configured to maintain the target pressure applied by the plunger 101 in response to movement of the patient relative to a fixed position of the plunger 101. That is, the plunger 101 may be configured to be able to automatically adjust its position when otherwise fixed in response to movement of the patient. This may be particularly useful in situations wherein, for example, the patient’s body jerks upwards; in such a situation, the plunger 101 may be configured to move upwards along with the body in order to avoid an overpressure being applied to the abdominal aorta and other body parts. In particular, the pressure maintenance mechanism 110 may resiliently bias the plunger 101, once fixed, to maintain the pressure applied by the plunger 101 in response to movement of the patient relative to the fixed position of the plunger 101 such that, in response to movement of the patient, the plunger 101 automatically adapts its position to maintain the pressure set by the otherwise fixed position of the plunger 101. The pressure maintenance mechanism 110 may be configured to provide for resilient movement of the plunger 101 in response to a movement of the patient which would otherwise result in a pressure greater than an upper acceptable pressure threshold being applied to the patient. Similarly, the pressure maintenance mechanism 110 may be configured to provide for resilient movement of the plunger 101 in response to movement of the patient which would otherwise result in a pressure less than a lower acceptable pressure threshold being applied to the patient. That is, the pressure maintenance mechanism 110 may be configured to maintain the pressure applied by the plunger 101 within an acceptable pressure threshold range. The pressure maintenance mechanism 110 may be implemented using, for example, a spring-loaded mechanism. Other approaches may also be utilised in order to provide for the resilient bias applied by the pressure maintenance mechanism 110. The apparatus 100 further comprises a counter pressure part 112 configured to contact a support surface. The counter pressure part 112 is configured to provide the counter pressure against which the pressure applied by the plunger 101 acts. For example, the counter pressure part 112 may be a back plate 112 which contacts the support structure in use. The back plate 112 may be comprised of a flat plate which the patient’s back is placed against or over such that the patient’s bodyweight holds the back plate 112 against the support surface. In such an embodiment, the pressing of the back plate 112 against the patient’s back provides a counter pressure to the plunger 101 which presses against the patient’s front. As discussed previously, the support surface may be an operating table, hospital bed or other surface on which the patient’s body may be placed. An apparatus 100 comprising a back plate counter pressure part 112 may be particularly useful in situations where it is intended to keep the apparatus 100 stored away and only brought out for use when needed. Placing the apparatus 100 on the support surface and then lying the patient on the back plate 112 may reduce the amount of time needed to apply pressure to a user in contrast to embodiments which require additional setup. In alternative embodiments, the counter pressure part 112 may be a clamp or other fixing structure which is configured to be coupled to the support surface. For example, the counter pressure part 112 may be a clamp which attaches to a hospital bed or operating bed. In such an embodiment, a counter pressure may be provided by way of the force applied by the counter pressure part 112 to the support surface as the plunger 101 presses against the patient’s front. Embodiments which make use of clamps or similar counter pressure parts may be particularly beneficial for use in permanent or semi-permanent set-ups, such as in operating theatres. This may be particularly helpful where use of the apparatus 100 is anticipated for an upcoming caesarean section operation, as the apparatus 100 can be readily installed on the operating table. Where the apparatus 100 is pre-installed on an operating table, the apparatus 100 may be moveably coupled to the operating table such that the apparatus 100 can be swung into position when required and swung out of the way of the patient and the medical practitioners when not required. In such embodiments, the clamp may comprise a rotational clamping mechanism which allows for movement of the whole apparatus 100 relative to the support surface, such as the operating table. In embodiments wherein the counter pressure part 112 is a back plate 112, the back plate may comprise a first panel having a first major surface and a second panel having a first major surface. The first panel and the second panel may be foldable between an open position and a close position. The open position may be for positioning the back plate 112 under the back of a patient such that the first major surface of the first panel and the first major surface of the second panel can be placed in contact with the back of the patient. The closed position may be one in which the first major surface of the first panel faces the first major surface of the second panel, i.e. the two panels are folded together. The closed position may be helpful in order to allow for folding of what may otherwise be a large back plate 112. This may reduce the form- factor of the apparatus 100 in at least one dimension, thereby making the apparatus 100 easier to store when not in use. In one or more additional or alternative embodiments, the back plate 112 may be configured such that it is decouplable from the apparatus 100. Providing a separable back plate 112 may also provide the benefit of allowing the apparatus 100 to be more easily stored. In some embodiments, the back plate 112 may be both decouplable from the apparatus 100 and foldable, as previously described. The back plate 112 may comprise an aperture 113 located in order to provide access to the spine of the patient when the patient is placed on with back plate 112 with their naval located in the pressure application axis 104. Providing an aperture 113 provides access to the spine which may allow for palpation or the administration of intrathecal or epidural drugs. The apparatus 100 also comprises the intermediate member 111 which comprises a first end 114 and an opposing second end 115. The plunger 101 is coupled to the intermediate member 111 at its first end 113. The plunger 101 is further coupled to the counter pressure part 112 at the second end 115 of the intermediate member 111. The intermediate member 111 may be a rigid member which extends between the plunger 101 and the counter pressure part 112. By providing a rigid or partially rigid intermediate member 111, no circumferential pressure or other lateral pressure is applied to the patient and, instead, all of the pressure applied to the patient can be focussed in a linear direction directly onto the abdominal aorta of the patient; thus, unnecessary constriction of the patient is avoided. The intermediate member 111 may comprise a curved profile. The curved profile of the intermediate member 111 may curve away from the plunger 101, that is, the curved profile of the intermediate member 111 may curve away from the position that the patient is to be placed. This may be particularly beneficial, as it may allow for at least the plunger 101 to extend over the patient to the correct position while providing for additional space for the patient’s abdomen. This may provide benefits in being able to accommodate patients having different body mass indices (BMIs). The curved intermediate member may also be beneficial in allowing the intermediate member 111 to curve back towards the patient towards the base of the apparatus 100 in order to allow the counter pressure part to be placed close to the patient. The apparatus 100 may be configured such that the plunger 101 is moveable out of the pressure application axis 104 in order to provide a space for the user to be positioned in the pressure application axis 104. For example, the plunger 101 may be moveable such that its elongate body extends in, or substantially in, the plane of the pressure application axis. This may be achieved by providing for the rotation of the plunger 101 into the x-y plane, for example. Movement of the plunger 101 may be achieved by way of movement of: the plunger 101; a coupling mechanism 116 that couples the plunger to the intermediate member 111; or the intermediate member. In one or more embodiments, the intermediate member may comprise a first sub member 111a comprising the first end 114 of the intermediate member 111 and a second sub member 111b comprising the second end 115 of the intermediate member 111. The first and second sub members may be hingably coupled to each other and movement of the first sub member 111a relative to the second sub member 111b may provide for movement of the plunger 101 out of the pressure application axis 104. The coupling of the first and second sub members 111a, 111b may be configured in order to protect both the user and the patient from pinching. The apparatus 100 may further comprise a quick-release mechanism (not shown) configured to provide for movement of the plunger 101 away from the patient. The quick release mechanism may be activatable by way of a simple mechanism. The simple mechanism may require, for example, a single manual interaction or may be operable with a single hand. The quick release mechanism may provide safety functionality which allows the pressure applied to the user to be removed at short notice. The quick release mechanism may release the plunger 101 such that it no longer applies force to the patient. This may be achieved by way of loosening a grip between the intermediate member 111 and the plunger 101 such that the plunger 101 is forced away from the patient by the natural counter-pressure of the patient’s body. In other embodiments, the quick-release mechanism may form part of the intermediate member 111 and may provide for the intermediate member 111 moving or hingably opening such that the plunger 101 is removed from contact with the patient. In such embodiments, the quick-release mechanism may generally provide for movement of the plunger 101 out of the pressure application axis 104 in order to remove the pressure applied to the patient. The quick-release mechanism may be configured to provide for removal of the pressure applied to the patient based on: the pressing of a button, the flipping of a switch, the flipping of a latch or in any other suitable manner. The apparatus 100 may comprise a coupling mechanism 116 configured to provide for the coupling of the plunger 101 to the intermediate member 111. The coupling mechanism 116 may further provide for the decoupling of the plunger 101 from the intermediate member 111 such that the plunger 101 can be coupled or decoupled from the intermediate member 111. This functionality may provide for the plunger 101 to be a disposable plunger. Since the plunger 101 is the part which may be most likely to be contaminated by contact with the patient’s body and potentially blood, it may be preferable to be able to replace the plunger 101 entirely. The plunger 101 may be entirely disposable or it may simply be beneficial that they are replaceable so that the apparatus 100 can be used again quickly after a preceding use. A used plunger 101 may either be disposed of or cleaned in a suitable manner in order to provide for hygienic later use. One or more components which make up the first end 102 of the plunger 101 may be separable from the remainder of the plunger 101 such that those components in particular may be disposed of or cleaned in a suitable manner in order to provide or hygienic later use. The apparatus 100 finally comprises a pressure indicator (not shown) configured to provide an indication that a target pressure has been applied by the plunger 101. The pressure indicator may be a gauge which a numerical read-out of the pressure applied or it may be a simple indicator which changes when the correct pressure is applied. For example, the indicator may swap from red to green upon the application of a correct pressure. The pressure indicator may be further configured to provide for an indication of whether the pressure applied to the patient by the plunger 101 is greater than or less than the target pressure. This may be beneficial so that a user knows whether they need to increase or decrease the pressure applied to the patient without needing to check for a precise number. For example, the indicator may be a colour-based indication or under pressure, target pressure or over pressure or it may use a different visual indicator such as arrows, numbers or another approach. As a further example, the pressure indicator may comprise an LED indicator which changes colour in order to either provide an indication that the pressure applied by the plunger 101 is the target pressure, or within an acceptable range of the target pressure. The LED indicator may further provide an indication of over or under pressure. The pressure indicator may be configured to measure the pressure applied to the patient in any appropriate way. For example, in some embodiments the pressure indicator may provide its indication based on the compression of a spring 110 within the plunger 101 which is connected to the first end of the plunger 101. In such an embodiment, this may mean that the resilient biasing mechanism 110 may also provide for the pressure measurement required by the pressure indicator. In particular, the pressure indicator may be located at the second end 103 of the plunger 101 or may actually form the second end 103 of the plunger 101. Where the second end 103 of the plunger 101 is the pressure indicator, it may be configured to move in or out of the plunger 101 such that the indicator 103 may be covered by a main body of the plunger 101. This may allow for manual handling of the plunger. The pressure indicator may also be provided as a piston entirely within the main body of the plunger 101 and be visible through an aperture main body of the plunger 101. The aperture may be configured to provide for the ability to read the pressure indicator therethrough. For example, the aperture may comprise a transparent material or a translucent material or no material. Figure 5 shows a method of using an apparatus according to the foregoing disclosure. The method 500 comprises the step of receiving 501 a patient between the plunger and the support surface such that the naval of the patient is substantially in line with the pressure application axis. The method 500 further comprises moving 502 the plunger towards the patient in order to apply the target pressure to the patient. The method 500 finally comprises fixing 503 the plunger such that pressure applied to the patient is maintained.

Claims

CLAIMS 1. An apparatus configured to apply pressure to the abdominal aorta of a patient, the apparatus comprising: a plunger having a first end for contacting a patient and applying pressure to the abdominal aorta of the patient; a counter pressure part configured to contact a support surface; and an intermediate member having a first end and an opposite second end, wherein the intermediate member is a rigid member, wherein the rigid intermediate member is coupled to: the plunger at the first end of the intermediate member; and the counter pressure part at the second end of the intermediate member; and wherein the plunger is movable towards and away from a patient in order to respectively apply pressure to and relieve pressure from the abdominal aorta of the patient and wherein the apparatus is configured such that the position of the plunger is fixable such that pressure applied to the patient is maintained, the apparatus further comprising a pressure indicator configured to provide an indication that a target pressure has been applied by the plunger. 2 The apparatus of claim 1 wherein the plunger is moveable in a pressure application axis linearly towards and away from the patient in order to apply pressure to and relieve pressure from the abdominal aorta of the patient.

3. The apparatus of claim 1 or claim 2 further comprising a pressure maintenance mechanism configured to maintain the target pressure applied by the plunger in response to movement of the patient relative to a fixed position of the plunger.

4. The apparatus of claim 3 wherein the pressure maintenance mechanism resiliently biases the plunger, once fixed, to maintain the pressure applied by the plunger in response to movement of the patient relative to the fixed position of the plunger such that, in response to movement of the patient, the plunger automatically adapts its position to maintain the pressure set by the fixed position of the plunger.

5. The apparatus of any of claims 2 – 4 wherein the plunger is repositionable in a plane of the pressure application axis so that the plunger can be aligned with the naval of the patient.

6. The apparatus of any of claims 2 - 5 wherein the apparatus is configured such that the plunger is moveable out of the pressure application axis in order to provide a space for the patient to be positioned in the pressure application axis.

7. The apparatus of claim 6 wherein the intermediate member comprises a first sub member comprising the first end of the intermediate member and a second sub member comprising the second end of the intermediate member wherein the first and second sub members are hingably coupled and wherein hingably moving the first sub member relative to the second sub member causes the plunger to be moved out of the pressure application axis.

8. The apparatus of any preceding claim further comprising a coupling mechanism configured to provide for coupling and decoupling of the plunger from the intermediate member.

9. The apparatus of any preceding claim wherein the counter pressure part comprises a back-plate configured to be placed under the back of a patient.

10. The apparatus of claim 9 wherein the back plate comprises a first panel having a first major surface and a second panel having a first major surface and wherein the first panel and the second panel are foldable between: an open position for positioning the back-plate under the back of a patient such that the first major surface of the first panel and the first major surface of the second panel can be placed in contact with the back of the patient; and a closed position wherein the first major surface of the first panel faces the first major surface of the second panel.

11. The apparatus of any preceding claim wherein the first end of the plunger comprises a concave surface arranged for at least partially contacting and wrapping around a portion of a vertebral column of the patient.

12. The apparatus of any preceding claim wherein the first end of the plunger comprises a resiliently deformable material configured to resiliently deform when pressure is applied to a patient.

13. The apparatus of any of claims 2 – 12 wherein the plunger comprises a coarse movement mechanism and a fine movement mechanism wherein the coarse movement mechanism is configured to provide for movement of the coarse movement of the plunger in the pressure application axis and the fine movement mechanism is configured to provide for fine movement of the plunger in the pressure application axis.

14. The apparatus of any preceding claim wherein the intermediate member has a curved profile.

15. A method of using the apparatus of any of claims 1 – 14, the method comprising: receiving a patient between the plunger and the support surface such that the naval of the patient is substantially in line with the pressure application axis; moving the plunger towards the patient in order to apply the target pressure to the patient; and fixing the plunger such that pressure applied to the patient is maintained.

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