PRESSURE CELL HOLDER FOR AN EXTRACORPOREAL BLOOD TREATMENT MACHINE

Abstract

A pressure cell holder for attachment to a housing of an extracorporeal blood treatment machine, such as a dialysis machine. The pressure cell holder includes a gripping device for holding a pressure cell inserted into the pressure cell holder by enclosing or engaging the pressure cell, and an ejector mechanism for ejecting the pressure cell when the gripping device is released.

Claims

1.-15. (canceled)

16. A pressure cell holder for attachment to a housing of an extracorporeal blood treatment machine, the pressure cell holder comprising: a gripping device adapted to grip around or engage a pressure cell that is insertable into the pressure cell holder; an ejection mechanism comprising a spring mechanism and that is adapted to eject the pressure cell actively upon release of the gripping device; and a pressure transmission line, the pressure transmission line being configured to be fluidically connected to a fluid chamber of the pressure cell and to transmit a fluid pressure present in the fluid chamber to a pressure sensor of the extracorporeal blood treatment machine.

17. The pressure cell holder according to claim 16, wherein the spring mechanism comprises a pressure element that is spring-mounted to be pre-tensioned upon insertion of the pressure cell into the pressure cell holder and press against the pressure cell in a holding state in which the pressure cell is held by the gripping device.

18. The pressure cell holder according to claim 17, wherein the gripping device is mounted on the housing of the extracorporeal blood treatment machine via a shaft, and wherein the pressure element is received in the shaft and is spring-mounted.

19. The pressure cell holder according to claim 17, wherein a conical holder port element comprising the pressure transmission line is arranged or formed at an outer end of the pressure element.

20. The pressure cell holder according to claim 19, wherein a spring force of the spring mechanism is set to press the pressure element in the holding state against the pressure cell in such a way that a gas-tight connection is provided between the pressure cell and the pressure transmission line.

21. The pressure cell holder according to claim 16, wherein the pressure cell holder comprises at least one wall portion that at least partially defines a receiving chamber for receiving the pressure cell.

22. The pressure cell holder according to claim 21, wherein the at least one wall portion is provided with a slit for receiving at least one blood chamber port of the pressure cell.

23. The pressure cell holder according to claim 21, wherein an inner circumferential surface of the at least one wall portion forms a guide for the pressure cell.

24. The pressure cell holder according to claim 22, wherein the slit is a circumferential slit extending transversely to an insertion direction along the at least one wall portion, through which the gripping device is separated or formed as at least one elastically bendable clamp extending parallel to the circumferential slit at one front end of the at least one wall portion of the pressure cell holder, wherein the circumferential slit is adapted to receive the at least one blood chamber port upon rotation of the pressure cell.

25. The pressure cell holder according to claim 24, wherein the at least one circumferential slit is widened at one end to provide a latchable port receptacle.

26. The pressure cell holder according to claim 25, wherein a setback is provided at a front edge of the at least one wall portion, next to an attachment point of the at least one elastically bendable clamp.

27. The pressure cell holder according to claim 22, wherein the gripping device comprises a sleeve-shaped turning bolt rotatably mounted on an outer side of the at least one wall portion and having at least one L-shaped slit, the at least one L-shaped slit comprising: an axial portion which opens axially against the insertion direction on a front face of the turning bolt and which, in an open position of the turning bolt, overlaps the at least one axially extending slit provided in the wall portion in such a way that the at least one blood chamber port is receivable into the respective L-shaped slit and the slit, and a circumferential portion which forms a circumferentially extending slit end, the circumferential portion adapted to hold the at least one blood chamber port in a fixed position together with the slit in a closed position achievable by turning the turning bolt.

28. The pressure cell holder according to claim 24, wherein the ejection mechanism has a guide link with a slit running obliquely to an insertion direction, in particular to the circumferential slit or to the circumferential portion of the L-shaped slit.

29. The pressure cell holder according to claim 26, wherein the gripping device forms at least one snap-fit hook which is designed to engage behind the pressure cell when the pressure cell is inserted.

30. The pressure cell holder according to claim 17, wherein the gripping device forms a locking tab attached or displaceably mounted via a joint in such a way that, in a closed position, the locking tab extends over the pressure cell on a side opposite the spring mechanism in order to press and hold it against the spring mechanism.

31. The pressure cell holder according to claim 22, wherein the slit is provided in the inner circumferential surface of the at least one wall portion and serves as the guide link.

32. The pressure cell holder according to claim 24, wherein the ejection mechanism has a guide link with a slit running obliquely to the circumferential slit or to the circumferential portion of the L-shaped slit.

33. A pressure cell holder for attachment to a housing of an extracorporeal blood treatment machine, the pressure cell holder comprising: a gripping device adapted to grip around or engage a pressure cell that is insertable into the pressure cell holder; an ejection mechanism comprising a spring mechanism; and a pressure transmission line, the ejection mechanism comprising a spring mechanism with a pressure element which is spring-mounted to be pre-tensioned upon insertion of the pressure cell and presses against the pressure cell in a holding state in which the pressure cell is held by the gripping device and is adapted to eject the pressure cell actively upon release of the gripping device, and the pressure transmission line being configured to be fluidically connectable to a fluid chamber of the pressure cell and to transmit a fluid pressure present in the fluid chamber to a pressure sensor of the extracorporeal blood treatment machine.

Description

BRIEF DESCRIPTIONS OF THE DRAWING FIGURES

[0045] The present invention is described hereinafter with reference to preferred embodiments. However, these are only illustrative in nature and are not intended to limit the scope of protection of the present invention. Furthermore, identical reference signs are used for the same components in the description of the various embodiments in order to avoid redundant descriptions of the same.

[0046] FIG. 1 shows a pressure cell holder according to the invention and a pressure cell during an insertion process according to a first embodiment.

[0047] FIG. 2 shows the pressure cell holder according to the first embodiment and the pressure cell held therein.

[0048] FIG. 3 shows a pressure cell holder according to the invention according to a modification of the first embodiment.

[0049] FIG. 4 shows the pressure cell holder according to the modification of the first embodiment and the pressure cell held therein.

[0050] FIG. 5 shows a pressure cell holder according to the invention according to a second embodiment.

[0051] FIG. 6 shows the pressure cell holder according to the second embodiment and the pressure cell inserted therein.

[0052] FIG. 7 shows a pressure cell holder according to the invention according to a third embodiment.

[0053] FIG. 8 shows the pressure cell holder according to the third embodiment and the pressure cell inserted therein.

[0054] FIG. 9 shows a pressure cell holder according to the invention according to a fourth embodiment.

[0055] FIG. 10 shows the pressure cell holder according to the fourth embodiment and the pressure cell held therein.

[0056] FIG. 11 shows a spring mechanism using the first embodiment as an example.

[0057] FIG. 12, FIG. 13 and FIG. 14 show advantageous variants for attaching a seal using the example of the first embodiment.

DETAILED DESCRIPTION

[0058] FIG. 1 shows a first embodiment of the pressure cell holder 1 according to the invention, hereinafter also referred to as holder 1 for short, while a pressure cell 2, hereinafter also referred to as capsule 2 for short, is inserted frontally therein (during an insertion process). The pressure cell 2 has a main body 3, which in this example is essentially round and forms a rigid capsule, whose interior space is separated by a membrane 4 into two chambers, a blood chamber 5 and an air chamber 6, for pressure transmission. At a front side of the pressure cell 2 shown in this view, blood chamber ports 7 are provided, which are adapted to fluidically connect the pressure cell 2, more precisely its blood chamber 5, with a blood hose line of an extracorporeal blood treatment machine. On the rear side and not shown here, the pressure cell 2 has a preferably conical air chamber port 8, in particular a Luer connector, which is connected to the air chamber 6 in a fluid-conducting manner.

[0059] In the following description of the embodiments, it should be noted that the pressure cell 2 described here by way of example and assumed in all embodiments is inserted frontally into the holder 1, which is open towards the front. Since the capsule 2 is furthermore round and the associated holder forms at least one correspondingly round receptacle, an insertion direction is hereinafter also referred to as an axial direction and a circumferential direction refers to this round shape. However, it is understandable that the pressure cell can be formed differently, e.g. cuboid-shaped, or that it may be laterally insertable into the holder without changing the functional principle of the present invention.

[0060] The pressure cell holder 1 forms a pot-like receiving chamber 9 which is adapted to receive the pressure cell 2. The receiving chamber 9 has walls or wall portions 10 on two opposite sides, forming part of a sleeve, whose inner circumference substantially corresponds to an outer circumference of the pressure cell 2, to receive and guide it. The wall portions 10 have two diametrically opposite slits 11 (hereinafter referred to as axial slits) extending in the insertion direction, which are designed to receive the blood chamber ports 7 of the pressure cell 2, thereby ensuring a rotationally fixed position of the pressure cell 2 relative to the pressure cell holder 1. In addition, the receiving chamber 9 has two snap-fit hooks or spring hooks 12 opposite each other and angularly offset (preferably by 90°) with respect to the wall portions 10 and the axial slit ends 11 provided therein, which are elastically bent radially outwards when the pressure cell 2 is inserted and, when the pressure cell 2 has reached its final position, spring back or snap in and thereby grip around an edge of the pressure cell 2 with hook projections extending radially inwards. In other words, the spring hooks 12 serve as a gripping device.

[0061] The pot-like receiving chamber 9 formed by the holder 1 furthermore has a bottom 13, in which a holder port 14 (holder port element/port portion of the holder), in particular a matching Luer connector, compatible with the air chamber port 8 of the pressure cell 2 (port portion of the capsule) is provided. The holder port 14 is spring-mounted in the holder 1, in particular in an opening in the bottom 13 of the holder 1, wherein an associated spring mechanism 15, which will be described in more detail later, is housed in a shaft 16 of the holder 1.

[0062] When the pressure cell 2 is inserted into the holder 1, the holder port 14 and the air chamber port 8 are connected to each other and are pressed together by the spring mechanism 15 in sealing manner. Furthermore, the spring mechanism 15 serves to push or eject the pressure cell 2 out of the receiving chamber 9 when the gripping device or spring hook 12 is released, i.e. it serves as an ejection mechanism. A spring deflection and a spring force of the spring mechanism 15 are dimensioned accordingly. The shaft 16 of the holder 1 further serves to attach the holder 1 to a housing of an extracorporeal blood treatment machine. More specifically, the shaft 16 has a collar for contacting the housing of the extracorporeal blood treatment machine and thus for defining a position of the holder 1 relative thereto.

[0063] FIG. 2 shows the first embodiment of the pressure cell holder 1 according to the invention, in which the pressure cell 2 is inserted. It is clearly visible that the blood chamber ports 7 of the pressure cell 2 lie in the axial slit ends 11 of the holder 1 and that the pressure cell 2 is secured against rotation in this way. It can also be seen that the spring hooks 12 grip around an edge of the pressure cell 2 and thus fix it in position in the axial direction/insertion direction.

[0064] FIG. 3 and FIG. 4 show a pressure cell holder 1 according to a modification of the first embodiment of the invention individually and with an inserted pressure cell 2. Apart from the modification, this embodiment corresponds essentially to the first embodiment, which is why only differences are explained below. In contrast to the first embodiment, the pressure cell holder 1 shown here has only a single spring hook 12 as a gripping device. Furthermore, only one wall portion 10 is provided, which extends sleeve-like around the receiving chamber 9 and is interrupted only in the area of the spring hook 12. This means that a single, continuous wall portion 10 is provided at the location where the second spring hook 12 would be in the holder 1 according to the first embodiment.

[0065] FIG. 5 shows a second embodiment of the present invention. This corresponds largely to the preceding first embodiment and differs therefrom substantially on the basis of the gripping device and on the basis of an associated insertion method, which are explained below. The receiving chamber 9 formed by the holder 1 is surrounded by a circumferential, sleeve-like wall 10 which is uninterrupted in the insertion direction/axial direction. On two diametrically opposite sides, the wall 10 forms axial prolongations 17. In each of these prolongations 17, a slit or circumferential slit 18 extending in the same circumferential direction (i.e., rotationally symmetrical) and extending partially around the receiving chamber 9 is provided, said slit serving to receive the blood chamber ports 7 of the pressure cell 2. That is, the prolongations 17 are separated or partially separated from the wall 10 by the circumferential slits 18 in such a way that they form clamps or wings as the gripping device that extend at the front (at a front edge) from the wall 10 in the circumferential direction.

[0066] The circumferential slits 18 are each uniformly narrow in their course, wherein they may widen slightly at their inputs and open towards the front/font side. In other words, the circumferential slit 18 may extend beyond the associated prolongation 17 into an intermediate portion of the wall 10 to form a kind of receptacle funnel at a transition between the prolongation 17 and this intermediate portion of the wall 10. Furthermore, the circumferential slits each form, at their other closed (sack) end, a round, expanded port receptacle 19 or a widening to latch the blood chamber ports 7. Behind the prolongations 17, at the side of the port receptacles 19, the wall 10 has a setback 20, whereby a flexibility of the clamps/wings formed by the prolongations 17 is increased.

[0067] In order to insert the pressure cell 2 into the holder 1, the pressure cell 2 is placed in/at the receiving chamber 9, as shown in FIG. 6, in such a way that the blood chamber ports 7 lie at the diametrically opposite inputs of the circumferential slits 18 or the reception funnels formed thereby. If the pressure cell 2 is now rotated in a bayonet-like manner in the circumferential direction relative to the pressure cell holder 1, the blood chamber ports 7 slide through the circumferential slits 18, wherein the circumferentially extending clamps formed by the prolongations 17 are elastically expanded in the axial direction and, if applicable, twist slightly. When the blood chamber ports 7 reach the circularly expanded port receptacles 19 of the circumferential slits 18, the elastically deformed clamps retract and thus lock the blood chamber ports 7 in an end position formed by the port receptacles 19. During this insertion process, as well as during an exactly reversed release of the capsule from the holder 1, the circumferential slits 18 (more precisely, the wall rims of the clamp and of a rear wall portion enclosing the circumferential slits 18) serve as a guide link, if applicable, to form at least part of the ejection mechanism according to the invention. Additionally or alternatively, a spring mechanism 15, as will be described in more detail later, is provided at/in the bottom 13 of the holder as at least a part of the ejection mechanism. The spring mechanism 15 and the guide link may also form a combined ejection mechanism.

[0068] FIG. 7 and FIG. 8 show a third embodiment of the present invention. Like the preceding embodiments, the holder 1 shown here has a pot-like receiving chamber 9. This receiving chamber 9 is formed by an inner sleeve with a bottom 13 and a wall with two diametrically opposite wall portions 10 extending in the insertion direction/axial direction. In the wall portions 10, similar to FIG. 1, a (respective) axial slit 11 is provided for receiving the blood hose ports 7 of the pressure cell 2. An inner surface of the wall portions 10 serves to receive and guide an outer circumference of the pressure cell 2. On the other hand, an outer surface of the wall portions 10 serves to rotatably hold and support a ring mandrel 21 relative to the receiving chamber 9. On an outer circumferential surface, the ring mandrel 21 has circumferentially distributed depressions which serve to improve gripping by a user. The ring mandrel 21 is a sleeve which has two diametrically opposite, substantially L-shaped slits 22 which are open in the same direction as the axial slits 11, towards the front/front edge of the ring mandrel 21, where they form an axial portion. Furthermore, each L-shaped slit 22 has a circumferential portion which bends from the axial portion at an angle equal to or greater than 90° and thus extends at least partially in the circumferential direction around the receiving chamber 9.

[0069] In order to fix the pressure cell 2 in the holder 1 of the third embodiment, the ring mandrel 21 is rotated relative to the receiving chamber 9 such that the openings/inputs of the axial slits 11 and the openings/inputs of the axial portions of the L-shaped slits 22 are aligned with each other, as shown in FIG. 8. Subsequently, the pressure cell 2 is inserted into the receiving chamber 9 in such a way that the blood hose ports 7 are located in the axial slit ends 11 and the axial portions of the L-shaped slit ends 22. If the ring mandrel 21 is now rotated relative to the pressure cell 2, the circumferential portions of the L-shaped slits 22 slide over the blood hose ports 7. In this way, the pressure cell 2 is secured against rotation by the axial slits 11 and secured in the axial direction by the circumferential portion of the L-shaped slits 22.

[0070] Similar to the aforementioned second embodiment, an ejection mechanism may be provided by a spring mechanism 15 provided in/at the bottom 13 of the holder, as will be described in more detail later, as at least a part of the ejection mechanism, and/or at least a part of the ejection mechanism may be provided by the circumferential portions 19 of the L-shaped slits 22 being oblique and serving as a guide link, as explained above with reference to the circumferential slits according to the second embodiment. The spring mechanism 15 and the guide link may also form a combined ejection mechanism.

[0071] FIG. 9 and FIG. 10 show a fourth embodiment of the holder 1 of the present invention with and without pressure cell 2 inserted. According to this embodiment, the holder 1 has a base plate which forms the bottom 13 and in/on which a spring mechanism 15 is provided as an ejection mechanism, in particular a spring mechanism 15 described later, as well as a holder port 14 which is compatible with the air chamber port 8 of the pressure cell 2. In this embodiment, an optionally pluggable port for quick assembly to a housing is provided at a rear side of the base plate, wherein the base plate is adapted to abut the housing in an assembly state. Furthermore, two opposite wall portions 10 are provided, in this example each terminating flatly on the outside with an edge of the base plate, said wall portions 10 extending perpendicularly to the base plate or in the insertion direction or axial direction. As in the aforementioned embodiments, the wall portions 10 form a round inner circumferential surface that serves to receive and guide an outer circumference of the pressure cell 2, and also have axial slits 11 that serve to receive the blood chamber ports 7 of the pressure cell 2.

[0072] Angularly offset (by 90°) from the opposite wall portions 10, a hinge bead 23 and a resilient locking hook 24 that is directed radially outwards are also provided opposite each other, projecting forward at the edge of the base plate. The hinge bead 23 forms a hinge with a hinge axis running parallel to the bottom 13 and the edge of the base plate, around which a locking tab 25 hinged to the hinge can rotate. The resilient locking hook 24, which is opposite the hinge bead 23, forms an snap-fit hook directed outwards, as an example here, for engagement with the locking tab 22.

[0073] The locking tab 25 substantially forms a hinge-mounted frame with two longitudinal struts 26 having a kink such that, when closed, the locking tab 25 lies roof-like over the bottom 13, in particular centrally over the pressure cell 2. Near the kink, the locking tab 25 can provide depressions for receiving the pressure cell 2 as well as an abutment ring 27 for abutment against the capsule 2 to hold it in the holder 1 against the force of the spring mechanism 15, as shown in FIG. 10. A transverse strut disposed at the free end of the locking tab 25 forms an engagement edge 28 for form-fit retention of the locking hook 24.

[0074] In order to insert the pressure cell 2 into the holder 1 according to this embodiment, the locking tab 25 is first opened or swiveled outwards/forwards. The pressure cell 2 is then inserted into the receiving chamber 9 in such a way that the blood chamber ports 7 lie in the axial slit ends 11 and the air chamber port 8 and the holder port 14 are connected to each other. The user then flips the locking tab 25 so that it presses on the main body 3 of the pressure cell 2, in particular with the abutment ring 27, in order to press the capsule against the spring mechanism 15 and create a gas-tight connection between the air chamber port and the holder port 14. In an end position, the transverse strut is pushed over the locking hook 24 so that it grips around/engages the engagement edge 28 and locks the locking tab 25.

[0075] FIG. 11 shows the pressure cell holder 1 according to the first embodiment with a pressure cell 2 inserted therein in longitudinal section to illustrate a spring mechanism 15 according to the invention as the ejection mechanism or as part thereof. It is to be understood that only the first embodiment is chosen as an example and that the same spring mechanism 15 can be likewise arranged in the modified first and in the fourth embodiment as well as possibly also in the second and third embodiment, in each case in a bottom 13, in particular shaft 16, of the corresponding holders 1.

[0076] In the holder shown in FIG. 11, the two diametrically opposite snap-fit hooks or spring hooks 12 are shown, which grip around one edge of the pressure cell 2 inserted in the holder. Furthermore, the inner structure of the pressure cell 2 with the outer blood chamber 5, the inner air chamber 6, the membrane 4 arranged in between and one of the blood chamber ports 7 can be seen. An air chamber port 8 is provided on the air chamber 6 in fluid conduction therewith, which in the inserted state of the capsule 2 projects into a shaft 16 of the holder 1 and which has a conical inner surface. The conical inner surface sits on a holder port 14 forming an outer cone, which is preferably provided with a soft plastic layer 29, in particular a silicone layer, as a seal (for sealing between the outer cone and the conical inner surface). The holder port 14 is mounted on a mechanically stable (deformation-resistant, in particular compression-resistant or rigid), preferably metallic, compression member 30 and forms a pressure element together with the latter. The compression member 30 extends through the shaft 16 and is mounted therein so as to be axially displaceable via a spring assembly 31, a spiral spring being shown here as an example. The spring assembly 31 and the compression member 30 form the spring mechanism 15 as a (possibly partial) ejection mechanism. The compression member 30 has at its inner end, which may project into the housing of the extracorporeal blood treatment machine, a port 37, e.g. for use with a pressure sensor. Furthermore, the compression member 30 and the spring 31 are accommodated in a sleeve which is screwed into the shaft 16 and can thus be easily released, e.g. for maintenance purposes.

[0077] FIG. 12, FIG. 13 and FIG. 14 also show the pressure cell holder according to the first embodiment in longitudinal section with further modifications and serve to illustrate various sealing arrangements. Apart from these modifications, it can be assumed that the illustrated holders 1 are essentially of the same construction, which is why only differences are explained below. For example, it is understood that although, for simplicity, no spring mechanism 15 is shown in these figures, nevertheless such a spring mechanism 15 formed in accordance with FIG. 11 is or may be arranged therein accordingly.

[0078] As shown in FIG. 12, as an alternative to the soft plastic layer 29 not shown here, an O-ring 32 may be received as a seal on the outer cone of the holder port 14 in an outer circumference groove, making the seal easier to maintain, in particular making it replaceable. In this case, preferably a capsule 2 can be used in which the air chamber port 8 is provided with a straight cylindrical inner surface against which the O-ring 32 abuts, which is easier to manufacture and further allows a higher axial position tolerance. Furthermore, if the holder port 14 is attached to a compression member 30, i.e. is arranged on a spring mechanism 15 as (part of) an ejection mechanism, then when the gripping device, in this example the snap-fit hook, is released, the spring mechanism 15 acts on the capsule 2 via the frictional force between the O-ring and the straight cylindrical inner surface of the air chamber port 8 to eject it. In the second or third embodiment, if no spring mechanism 15 is provided, but only a guide link 18/22 is provided as an ejection mechanism, the outer cone may also be rigidly arranged in the shaft 16.

[0079] In FIG. 13, a carrier sleeve 33 is inserted at the front (facing the inserted pressure cell 2) at an inlet of the shaft 16, in which an inner circumferential groove with an O-ring 34 inserted therein is provided as a seal, alternatively or in addition to the soft plastic layer 29 or the O-ring 32 arranged on the outer cone described above. The O-ring 34 shown in FIG. 13 is in sealing contact with a straight cylindrical outer surface of the air chamber port 8 and thus seals off the air chamber port 8 from the shaft 16. This is advantageous in particular when the shaft 16 itself forms part of a pressure transmission line between the capsule 2 and the pressure sensor and can be provided both in embodiments with and without spring mechanism 15 as ejection mechanism.

[0080] In FIG. 14, in contrast to FIG. 13, no carrier sleeve 33 is provided as a carrier for the O-ring 34, but an O-ring 35 is provided in an outer circumferential groove on a straight cylindrical outer surface of the air chamber port 8 and is in sealing contact with a straight cylindrical inner circumferential surface of the shaft 16. This can be realized in embodiments with and without spring mechanism 15 according to the modification according to FIG. 13 explained above and can be provided in particular for a shaft 16 acting as a pressure transmission line, but is easier to manufacture and maintain compared to the modification according to FIG. 13.