Pump-valve assembly for use in a blood circulation system.

Abstract

A pump-valve assembly for use in a blood circulation system comprises a three-way valve (5) which has a bifurcated Y-shaped conduit structure, whose branched-off first conduit (1) has a first check-valve and in use automatically functions as exit channel for blood flow during an expel stroke of a pulsatile pump (4), and whose branched-off second conduit (2) has a second check-valve and in use automatically functions as entry channel for blood flow during an intake stroke of the pulsatile pump. The first and second check-valves have first and second moveable check-valve bodies (41, 42) having first and second droplet shapes, respectively. The pump-valve assembly has favourable properties with respect to performance and reliability, including with respect to minimizing hemolysis, as well as with respect to manufacturability of the assembly.

Description

[0001] Title: Pump-valve assembly for use in a blood circulation system.

[0002] The invention relates to a pump-valve assembly for use in a blood circulation system, wherein:

[0003] the pump -valve assembly comprises a pulsatile pump and a three-way valve;

[0004] the pulsatile pump comprises a pump chamber for holding blood, wherein the pulsatile pump is controllably drivable to perform intake strokes and expel strokes, respectively, by controllably increasing and decreasing, respectively, the volume of the pump chamber for displacing blood into and out of the pump chamber, respectively; and

[0005] the three-way valve comprises a first port which is configured to be connected to a blood supply line for supplying blood to a patient, a second port which is configured to be connected to a blood return line for receiving blood from the patient, and a third port which is connected or connectable to said pump chamber of the pulsatile pump via a blood pump line.

[0006] As used herein, the above-mentioned pulsatile pump having the aboverecited features may, for example, be a diaphragm pump (also called membrane pump), a plunger pump, a bellows pump, or the like.

[0007] Fig. 1 of WO 2024 / 128910 Al discloses a blood circulation system which comprises a paracorporeal pump-valve assembly having the above-recited features. Therein, said Fig. 1 shows a pulsatile pump (15) and a three-way valve (1). Said Fig.

[0008] 1 of WO 2024 / 128910 Al further shows a blood pump line (LI), a blood supply line (L2) and a blood return line (L3) of said blood circulation system.

[0009] It is an object of the present invention to provide at least an alternative pump-valve assembly having a pulsatile pump for use in a blood circulation system, wherein said alternative pump-valve assembly has favourable properties with respect to performance and reliability, including with respect to minimizing hemolysis (i.e. minimizing destruction of red blood cells), as well as with respect to manufacturability of the assembly.

[0010] For that purpose the invention provides a pump-valve assembly according to the appended independent claim 1. Preferable embodiments of the invention are provided by the appended dependent claims 2-7.Hence, the invention provides a pump -valve assembly for use in a blood circulation system, wherein:

[0011] the pump -valve assembly comprises a pulsatile pump and a three-way valve;

[0012] the pulsatile pump comprises a pump chamber for holding blood, wherein the pulsatile pump is controllably drivable to perform intake strokes and expel strokes, respectively, by controllably increasing and decreasing, respectively, the volume of the pump chamber for displacing blood into and out of the pump chamber, respectively; and

[0013] the three-way valve comprises a first port which is configured to be connected to a blood supply line for supplying blood to a patient, a second port which is configured to be connected to a blood return line for receiving blood from the patient, and a third port which is connected or connectable to said pump chamber of the pulsatile pump via a blood pump line;

[0014] characterized in that:

[0015] the three-way valve comprises a bifurcated Y-shaped conduit structure, which comprises a first conduit, a second conduit and a third conduit, wherein each of the first conduit and the second conduit is branched off from the third conduit, and wherein said first port, said second port and said third port are ports of the first conduit, the second conduit and the third conduit, respectively;

[0016] the first conduit internally comprises a first check-valve, which comprises a first check-valve seat, which is situated at a fixed location of the first conduit, and a first moveable check-valve body, which is moveably suspended relative to the first conduit, wherein the first check-valve seat is extending circumferentially around a first conduit center line of the first conduit so as to circumferentially enclose a first check-valve passageway of the first check-valve, and wherein the first moveable check-valve body is substantially shaped according to a first droplet-shape having a first droplet center line, and wherein the first moveable check-valve body along said first droplet center line has a first nose portion and a first tail portion, which correspond to nose and tail portions of said first droplet-shape, respectively, wherein the first moveable check-valve body is facing with said first nose portion and said first tail portion to said third port and said first port, respectively, and wherein the first moveable check-valve body is reciprocally movable, relative to saidfirst conduit, in opposite directions parallel to said first droplet center line and between:

[0017] - a first closed position in which the first nose portion is sealingly lying against the first check-valve seat for preventing fluid flow through said first checkvalve passageway in a direction from the first port to the third port, thereby defining a first closed condition of the first check-valve, and

[0018] - a first open position in which the first nose portion is not lying against the first check-valve seat for allowing fluid flow through said first check-valve passageway in a direction from the third port to the first port, thereby defining a first open condition of the first check-valve; and

[0019] the second conduit internally comprises a second check-valve, which comprises a second check-valve seat, which is situated at a fixed location of the second conduit, and a second moveable check-valve body, which is moveably suspended relative to the second conduit, wherein the second check-valve seat is extending circumferentially around a second conduit center line of the second conduit so as to circumferentially enclose a second check-valve passageway of the second check-valve, and wherein the second moveable check-valve body is substantially shaped according to a second droplet-shape having a second droplet center line, and wherein the second moveable check-valve body along said second droplet center line has a second nose portion and a second tail portion, which correspond to nose and tail portions of said second droplet-shape, respectively, wherein the second moveable check-valve body is facing with said second nose portion and said second tail portion to said second port and said third port, respectively, and wherein the second moveable check-valve body is reciprocally movable, relative to said second conduit, in opposite directions parallel to said second droplet center line between:

[0020] - a second closed position in which the second nose portion is sealingly lying against the second check-valve seat for preventing fluid flow through said second check-valve passageway in a direction from the third port to the second port, thereby defining a second closed condition of the second checkvalve, and

[0021] - a second open position in which the second nose portion is not lying againstthe second check-valve seat for allowing fluid flow through said second checkvalve passageway in a direction from the second port to the third port, thereby defining a second open condition of the second check-valve;

[0022] whereby in an operation condition of the pump-valve assembly in which said first port is connected to said blood supply line, said second port is connected to said blood return line, and said third port is connected to said pulsatile pump via said blood pump line:

[0023] - performing an expel stroke of the pulsatile pump causes the first check-valve to be in said first open condition and causes the second check-valve to be in said second closed condition; and

[0024] - performing an intake stroke of the pulsatile pump causes the second checkvalve to be in said second open condition and causes the first check-valve to be in said first closed condition.

[0025] Hence, the three-way valve of the pump-valve assembly according to the invention has the special features that it has a bifurcated Y-shaped conduit structure, whose branched-off first conduit with its first check-valve in use automatically functions as exit channel for blood flow during an expel stroke of the pulsatile pump, and whose branched-off second conduit with its second check-valve in use automatically functions as entry channel for blood flow during an intake stroke of the pulsatile pump. Therein, the first and second droplet shapes of the first and second moveable check-valve bodies are minimizing turbulence of the blood flow within the first conduit and the second conduit during expel strokes and intake strokes of the pulsatile pump. Said minimizing of turbulence results in minimizing hemolysis (i.e. minimizing destruction of red blood cells). At the same time, said first and second droplet shapes are minimizing fluid drag of the blood flow through the first and second counduits, which is favourable for the performance of the pump-valve assembly. Additionally, the invention allows for avoiding occurrences of stagnant / trapped blood flow areas within the bifurcated Y-shaped conduit structure and along the first and second check-valves of the three-way valve. With every intake stroke or expel stroke of the pulsatile pump all the blood is “flushed” out of the three-way valve.

[0026] In a preferable embodiment of a pump-valve assembly according to theinvention:

[0027] a first exterior surface of the first tail portion of the first moveable checkvalve body of the first check-valve has first recess structure in deviation from said first droplet-shape according to which the first moveable check-valve body is substantially shaped; and / or

[0028] a second exterior surface of the second tail portion of the second moveable check-valve body of the second check-valve has second recess structure in deviation from said second droplet-shape according to which the second moveable check-valve body is substantially shaped.

[0029] Thanks to said first recess structure, the surface area and drag coefficient of the first exterior surface of the first tail portion of the first moveable check-valve body is effectively increased when blood flows along the first moveable check-valve body in a direction from the first tail portion towards the first nose portion. This causes the blood flow to apply an increased closing pressure on the first moveable check-valve body of the first check-valve, which results in a quicker closing response and better sealing action of the first check-valve. Thanks to said second recess structure, the surface area and drag coefficient of the second exterior surface of the second tail portion of the second moveable check-valve body is effectively increased when blood flows along the second moveable check-valve body in a direction from the second tail portion towards the second nose portion. This causes the blood flow to apply an increased closing pressure on the second moveable check-valve body of the second check-valve, which results in a quicker closing response and better sealing action of the second check-valve.

[0030] In another preferable embodiment of a pump-valve assembly according to the invention:

[0031] the first moveable check-valve body, together with first suspension means configured for moveably suspending the first moveable check-valve body relative to the first conduit, are injection moulded as one first integral piece from a thermoplastic elastomer; and / or

[0032] the second moveable check-valve body, together with second suspension means configured for moveably suspending the second moveable check-valve body relative to the second conduit, are injection moulded as one second integral piece from a thermoplastic elastomer.Thanks to injection moulding the first and / or second moveable checkvalve body and the first and / or second suspension means as one first and / or one second integral piece from a thermoplastic elastomer, said first and / or second integral piece can be manufactured at low costs and can furthermore be assembled within the first and / or second check-valve in a simple manner, which further reduces the manufacturing costs of the pump -valve assembly. Reducing manufacturing costs is especially beneficial when the pump-valve unit has to be manufactured in large numbers, which is the case when at least the three-way valve of the pump-valve assembly is used as a disposable part of blood circulation systems.

[0033] In another preferable embodiment of a pump-valve assembly according to the invention:

[0034] the first check-valve seat is formed by an inner wall surface of a section of the first conduit, wherein said section of the first conduit defines a fluid conducting space, which is locally narrowing towards said first check-valve passageway when considered in a direction from the first tail portion to the first head portion of the first moveable check-valve body; and / or

[0035] the second check-valve seat being formed by an inner wall surface of a section of the second conduit, wherein said section of the second conduit defines defines a fluid conducting space, which is locally narrowing towards said second check-valve passageway when considered in a direction from the second tail portion to the second head portion of the second moveable check-valve body.

[0036] Thanks to the first check-valve seat being formed by an inner wall surface of a section of the first conduit in the above-mentioned way, the first checkvalve seat is an integral part of the first conduit, which reduces the manufacturing costs of the pump -valve assembly. Thanks to the second check-valve seat being formed by an inner wall surface of a section of the second conduit in the above-mentioned way, the second check-valve seat is an integral part of the second conduit, which reduces the manufacturing costs of the pump-valve assembly.

[0037] Reducing manufacturing costs is especially beneficial when the pump-valve unit has to be manufactured in large numbers, which is the case when at least the three-way valve of the pump-valve assembly is used as a disposable part of blood circulation systems.In another preferable embodiment of a pump-valve assembly according to the invention a first bifurcation angle of the bifurcated Y-shaped conduit structure is smaller than 60 degrees and a second bifurcation angle of the bifurcated Y-shaped conduit structure is smaller than 60 degrees, wherein said first bifurcation angle is defined as the largest occurring local acute angle of deflection between said first conduit center line of the first conduit and a third conduit center line of the third conduit, and wherein said second bifurcation angle is defined as the largest occurring local acute angle of deflection between said second conduit center line of the second conduit and said third conduit center line of the third conduit.

[0038] Thanks to the first bifurcation angle and the second bifurcation angle of the bifurcated Y-shaped conduit structure being smaller than 60 degrees in the above-mentioned way, fluid drag and turbulence of the blood flow within the three-way valve during expel strokes and intake strokes of the pulsatile pump are further minimized, which results in further minimizing hemolysis and further improving the performance of the pump-valve assembly.

[0039] More preferably, said first bifurcation angle of the bifurcated Y-shaped conduit structure is smaller than 50 degrees and said second bifurcation angle of the bifurcated Y-shaped conduit structure is smaller than 50 degrees. This results in yet further minimizing hemolysis and yet further improving the performance of the pump-valve assembly.

[0040] Yet more preferably, said first bifurcation angle of the bifurcated Y-shaped conduit structure is smaller than 40 degrees and said second bifurcation angle of the bifurcated Y-shaped conduit structure is smaller than 40 degrees. This results in still yet further minimizing hemolysis and still yet further improving the performance of the pump-valve assembly.

[0041] In the following, the invention is further elucidated with reference to nonlimiting embodiments and with reference to the schematic figures in the appended drawing, in which the following is shown.

[0042] Fig. 1 shows an example of an embodiment of a paracorporeal pump-valve assembly according to the invention, wherein in Fig. 1 the pump-valve assembly is used in a non-limiting example of a blood circulation system.

[0043] Fig. 2 shows, in a side view, the pulsatile pump of the pump-valve assembly of Fig. 1.Fig. 3 shows, in a top view, the three-way valve of the pump -valve assembly of Fig. 1.

[0044] Fig. 4 shows the three-way valve of Fig. 3 in an exploded perspective view.

[0045] Fig. 5 A shows, in a perspective view, a first check-valve unit which comprises the first moveable check-valve body of the first check-valve of the three-way valve of Fig. 4 together with first suspension means via which the first moveable check-valve body is moveably suspended relative to the first conduit of the three-way valve.

[0046] Fig. 5B shows the first check-valve unit of Fig. 5A in a side view. Fig. 5C shows the first check-valve unit of Fig. 5A in a front view.

[0047] Fig. 6 shows the three-way valve of Fig. 3 in a cross-section, which is taken through a midplane of the three-way valve, wherein the first conduit center line, the second conduit center line and the third conduit center line of the three-way valve are lying in said midplane, and wherein the first check-valve is in the FIRST OPEN condition, and wherein the second check-valve is in the SECOND CLOSED condition, which occurs in use of the pump-valve assembly during an expel stroke of the pulsatile pump.

[0048] Fig. 7 shows the situation of Fig. 6 again, however, wherein this time the first check-valve is in the FIRST CLOSED condition, and the second check-valve is in the SECOND OPEN condition, which occurs in use of the pump -valve assembly during an intake stroke of the pulsatile pump.

[0049] The reference signs used in the embodiments of Figs. 1-7 are referring to the above-mentioned parts and aspects of the invention, as well as to related parts and aspects, in the following manner.

[0050] AO - aorta

[0051] 1 - first conduit

[0052] 2 - second conduit

[0053] 3 - third conduit

[0054] 4 - pulsatile pump

[0055] 5 - three-way valve

[0056] 6 - pump chamber

[0057] 7 - blood supply line8 - blood return line

[0058] 9 - blood pump line

[0059] 10 - pneumatic chamber

[0060] 11 - first check-valve unit

[0061] 12 - second check-valve unit

[0062] 14 - internal flow channel

[0063] 15 - sleeve

[0064] 16 - displacement structure

[0065] 17 - rigid housing

[0066] 18 - pneumatic conduit

[0067] 19 - flexible membrane

[0068] 21 - first port

[0069] 22 - second port

[0070] 23 - third port

[0071] 24 - upper main valve-housing part 25 - lower main valve-housing part 26 - expel stroke blood flow lines

[0072] 27 - intake stroke blood flow lines31 - first check-valve seat

[0073] 32 - second check-valve seat

[0074] 41 - first moveable check-valve body 42 - second moveable check-valve body 51 - first conduit center line

[0075] 52 - second conduit center line

[0076] 53 - third conduit center line

[0077] 61 - first check-valve passageway

[0078] 62 - second check-valve passageway 71 - first droplet center line

[0079] 72 - second droplet center line

[0080] 81 - first nose portion

[0081] 82 - second nose portion

[0082] 91 - first tail portion

[0083] 92 - second tail portion101 - first bifurcation angle

[0084] 102 - second bifurcation angle

[0085] 111 - first recess structure

[0086] 112 - second recess structure

[0087] 121 - first mounting ring

[0088] 122 - second mounting ring

[0089] 131 - first elastic suspension coils

[0090] 132 - second elastic suspension coils

[0091] 141 - first barbed connector

[0092] 142 - second barbed connector

[0093] 143 - third barbed connector

[0094] Based on the above introductory description, including the brief description of the drawing figures, and based on the above-listed reference signs used in Figs. 1-7, the embodiments of Figs. 1-7 are for the greatest part readily self-explanatory. The following extra explanations are given.

[0095] Reference is first made to Figs. 1-2 to illustrate the use, in a blood circulation system, of the pulsatile pump 4 and the three-way valve 5 of the pumpvalve assembly according to the present invention.

[0096] Fig. 1 illustrates clinical use of the pulsatile pump 4 for causing blood pressure pulsations in a patient’s aorta AO. Fig. 2 shows a non-limiting example of such a pulsatile pump 4 (in partly look-through view).

[0097] It is noted that Figs. 1-2 of the present disclosure show exactly the same parts and aspects as Figs. 1-2 of the above-mentioned document WO 2024 / 128910 Al, except for one difference. The only difference is that Fig. 1 of the present disclosure shows the three-way valve 5 which, according to the present invention, is of a different type than the three-way valve of Fig. 1 of WO 2024 / 128910 Al.

[0098] Nonetheless, the three-way valve 5 of the present disclosure has certain parts and certain aspects in common with the three-way valve disclosed in WO 2024 / 128910 Al. It is noted that in relation to such parts and aspects which are in common between the present disclosure and WO 2024 / 128910 Al, such as certain uses of such a valve and such a pump, and such as dimensions, materials, etcetera, of certain parts of the valves, pumps, lines, fittings, etcetera, the present invention can be embodied and used in the same or similar manners as known from WO2024 / 128910 Al. For that reason, the present disclosure will not unnecessarily reiterate all such common parts and aspects. Furthermore, WO 2024 / 128910 Al is incorporated herein by reference.

[0099] It is preferred that the pulsatile pump 4 of Figs. 1-2 of the present disclosure has a relatively simple configuration, providing reliable and durable blood flow action. To that aim the pulsatile pump 4 includes the displacement structure 16 for, while in operation, alternatingly applying suction and pressure, in particular for cyclically driving fluid displacement through the blood pump line 9, wherein a flow path between the displacement structure 16 of the pulsatile pump 4 and the third port 23 of the three-way valve 5 is preferably unobstructed (i.e. continuously open) after assembly.

[0100] For example, the pulsatile pump 4 of Fig. 2 can have a displacement structure 16 in the form of a rigid housing 17 which encloses a chamber which is divided by the shown flexible membrane 19 into the pump chamber 6 (for containing blood) on the distal side of the flexible membrane 19 and the pneumatic chamber 10 on the proximal side of the flexible membrane 19. The pump chamber 6 is connected to the blood pump line 9 (e.g. a tube or catheter) projecting from that displacement structure 16 and bounding an internal flow channel 14 for leading blood to and from the third port 23 of the three-way valve 5. The pneumatic chamber 10 can communicate with a sleeve 15 (see Fig. 2) for connection to a pneumatic conduit 18 communicating with the pneumatic drive system 100 (see Fig.

[0101] 1), known per se. For example, the system can include a driver configured to be synchronized with a heartbeat of the patient, for example a standard Intra-Aortic Balloon Pump (IABP) driver.

[0102] Hence, the displacement structure 16 can be driven by the pneumatic drive system 100 for alternatingly applying suction on the proximal side of the flexible membrane 19 for displacing blood from the three-way valve 5 via the blood pump line 9 to the pump chamber 6, as well as for applying pressure to the proximal side of the flexible membrane 19 for displacing blood from the pump chamber 6 via the blood pump line 9 to the three-way valve 5, thus driving a flow through the blood pump line 9 which reverses in a pulsating manner.

[0103] Hence, the pulsatile pump 4 is connectable to the third port 23 of the three-way valve 5 via a (single) blood pump line 9 (e.g. tubing, a catheter).Furthermore, the first port 21 of the three-way valve 5 is connected to the blood supply line 7 for supplying blood to a patient (e.g. to the aorta AO), and the second port 22 of the three-way valve 5 is configured to be connected to the blood return line 8 for receiving blood from the patient. Optionally, the blood supply line 7 can be provided with one or more blood treatment units and / or blood monitoring units 200, for example an oxygenator 200 (see Fig. 1), known per se, configured for treating and / or monitoring blood flowing via the blood supply line 7 to the patient during use of the system. It is preferred that the blood flow lines 7, 8, 9 are each made of resilient or elastic, flexible tubular material (e.g. a suitable elastomer, silicone rubber, polyvinylchloride or the like). It will be appreciated that the blood flow lines 7, 8, 9 can be catheters or catheter sections.

[0104] Reference is now made to Fig. 3, which shows, in a top view, the three-way valve 5 of the pump-valve assembly of Fig. 1. Fig. 3 shows the valve’s bifurcated Y-shaped conduit structure having the first conduit 1, the second conduit 2 and the third conduit 3. Fig. 3 further shows the first bifurcation angle 101 and the second bifurcation angle 102. The first bifurcation angle 101 is defined as the largest occurring local acute angle of deflection between the first conduit center line 51 of the first conduit 1 and the third conduit center line 53 of the third conduit 3. The second bifurcation angle 102 is defined as the largest occurring local acute angle of deflection between the second conduit center line 52 of the second conduit 2 and the third conduit center line 53 of the third conduit 3. In Fig. 3, the directions of the first conduit center line 51 and the second conduit center line 52 that correspond to said largest occurring local acute angles of deflection are indicated in orthogonal look-through view onto a cross-sectional midplane through the three-way valve 5. In the shown example, the first conduit center line 51, the second conduit center line 52 and the third conduit center line 53 are lying in said cross-sectional midplane. In the shown example, each of the first bifurcation angle 101 and the second bifurcation angle 102 is smaller than 40 degrees.

[0105] Fig. 4 shows the three-way valve 5 in an exploded perspective view, and illustrates how, in the shown example, a three-way valve according to the invention can be assembled during manufacturing of the three-way valve. The main valvehousing of the three-way valve 5 comprises the upper main valve-housing part 24, the lower main valve-housing part 25, the first barbed connector 141, the secondbarbed connector 142 and the third barbed connector 143. In the shown example, these two main valve-housing parts 24, 25 and the three barbed connectors 141, 142, 143 are each made from the same material, i.e. MABS (Methylmethacrylate acrylonitrile butadiene styrene).

[0106] In the shown example, the three-way valve 5 of Fig. 4 further comprises the first check-valve unit 11 and the second check-valve unit 12 of the first checkvalve and the second check-valve of the three-way valve 5, respectively. The first check-valve unit 11 comprises the first mounting ring 121, the first elastic suspension coils 131 and the first moveable check-valve body 41 of the first checkvalve. The second check-valve unit 12 comprises the second mounting ring 122, the second elastic suspension coils 132 and the second moveable check-valve body 42 of the second check-valve.

[0107] Lower edges of the upper main valve-housing part 24 can be glued to upper edges of the lower main valve-housing part 25, while at the same time the first barbed connector 141, the second barbed connector 142 and the third barbed connector 143 can be glued to the upper main valve-housing part 24 and the lower main valve-housing part 25, while at the same time the first check-valve unit 11 of the first check-valve, as well as the second check-valve unit 12 of the second checkvalve can be inserted in-between the upper main valve-housing part 24 and the lower main valve-housing part 25.

[0108] Figs. 5A-5C show the first check-valve unit 11 of the first check-valve of the three-way valve 5. In the shown example, the first check-valve unit 11, which comprises the first mounting ring 121, the first elastic suspension coils 131 and the first moveable check-valve body 41, is injection moulded as one integral piece from a biocompatible thermoplastic elastomer. In assembled condition of the three-way valve 5, the first check-valve unit 11 is received with its first mounting ring 121 in an annular recess on the inner side of the first conduit 1 of the three-way valve 5 (best seen in Figs. 6-7). As best seen in Fig. 5C, the first moveable check-valve body 41 is suspended via the first elastic suspension coils 131 to the first mounting ring 121. The flexible yet stiff properties of the thermoplastic elastomer of the first check-valve unit 11, combined with the droplet-shape design of the first moveable check-valve body 41 allows the first moveable check-valve body 41 to move back and forth depending on the direction of the flow, while staying concentrically inside thefirst mounting ring 121.

[0109] In the shown example, the second check-valve unit 12 of the second check-valve of the three-way valve 5 is identical to the first check-valve unit 11 of Figs. 5A-5C. That is, the second mounting ring 122, the second elastic suspension coils 132 and the second moveable check-valve body 42 are identical to the first mounting ring 121, the first elastic suspension coils 131 and the first moveable check-valve body 41, respectively, and they are also injection moulded as one integral piece from a biocompatible thermoplastic elastomer. However, as will be readily appreciated from Fig. 4 and Figs. 6-7, the second check-valve unit 12 of the second check-valve of the second conduit 2 is oriented with the second TAIL portion 92 facing the third conduit 3, while on the other hand the first check-valve unit 11 of the first check-valve of the first conduit 1 is oriented with the first NOSE portion 81 facing the third conduit 3.

[0110] Reference is now made more expressly to Figs. 6-7. The first check-valve, which is internally comprised in the first conduit 1, comprises the first check-valve unit 11 (see Figs. 5A-5C) as well as the first check-valve seat 31, which is situated at a fixed location of the first conduit 1. In the shown example, the first check-valve seat 31 is formed by an inner wall surface of a section of the first conduit 1, wherein said section of the first conduit 1 defines a first fluid conducting space, which is locally narrowing in a direction from the first tail portion 91 to the first head portion 81 of the first moveable check-valve body 41. The second check-valve, which is internally comprised in the second conduit 2, comprises the second check-valve unit 12 as well as the second check-valve seat 32, which is situated at a fixed location of the second conduit 2. In the shown example, the second check-valve seat 32 is formed by an inner wall surface of a section of the second conduit 2, wherein said section of the second conduit 2 defines a second fluid conducting space, which is locally narrowing in a direction from the second tail portion 92 to the second head portion 82 of the second moveable check-valve body 42.

[0111] In Fig. 6 the first check-valve is in its first OPEN condition due to a resultant fluid dynamic force action on the first moveable check-valve body 41 in a direction away from the first check-valve seat 31, said resultant fluid dynamic force action being caused by an expel stroke of the pulsatile pump 4. In Fig. 6, blood flow lines during said expel stroke are indicated by the arrows 26. Fig. 6 shows the firstcheck-valve passageway 61 which is in-between said annular first check-valve seat 31 and the first nose portion 81 of the first moveable check-valve body 41. In Fig. 7, on the other hand, the first check-valve is in its first CLOSED condition due to a resultant fluid dynamic force action on the first moveable check-valve body 41 in a direction towards the first check-valve seat 31, the last-mentioned resultant fluid dynamic force action being caused by an intake stroke of the pulsatile pump 4. In Fig. 7, blood flow lines during said intake stroke are indicated by the arrows 27. Accordingly, in Fig. 7 the first nose portion 81 is sealingly lying against the annular first check-valve seat 31.

[0112] In Fig. 7 the second check-valve is in its first OPEN condition due to a resultant fluid dynamic force action on the second moveable check-valve body 42 in a direction away from the second check-valve seat 32, the last-mentioned resultant fluid dynamic force action being caused by said intake stroke of the pulsatile pump 4 corresponding to said intake stroke blood flow lines 27. Fig. 7 shows the second check-valve passageway 62 which is in-between said annular second check-valve seat 32 and the second nose portion 82 of the second moveable check-valve body 42. In Fig. 6, on the other hand, the second check-valve is in its second CLOSED condition due to a resultant fluid dynamic force action on the second moveable check-valve body 42 in a direction towards the second check-valve seat 32, the last-mentioned resultant fluid dynamic force action being caused by said expel stroke of the pulsatile pump 4. Accordingly, in Fig. 6 the second nose portion 82 is sealingly lying against the annular second check-valve seat 32.

[0113] As mentioned, the pump -valve assembly according to the invention can be used in a blood circulation system, wich includes a driver configured to be synchronized with a heartbeat of the patient, for example a standard Intra-Aortic Balloon Pump (IABP) driver. Therein, the performance of the pump-valve assembly, connected to the standard IABP driver may typically be ≥ 5L / min at a frequency of 100 beats per minute. The maximum usage time may typically be 7 days. Typically biocompatible materials, such as MABS, may be used for housing parts of both the three-way valve and the pulsatile pump. The glue used in the three-way valve may preferably be the same glue as used in the pulsatile pump. The shelflife may typically be 3 years, both for the three-way valve and for the pulsatile pump. The frequency range of operation may typically be between 60 and 120 bpm. Operatingpressures may typically be around +500 mmHg and -300 mmHg. Implementing a safety factor of 2 for the applied driving pressures, the three-way valve and the pulsatile pump may typically be designed to endure internal pressures of + 1000 mmHg and -600 mmHg.

[0114] While the invention has been described and illustrated in detail in the foregoing description and in the drawing figures, such description and illustration are to be considered exemplary and / or illustrative and not restrictive. That is, the invention is not limited to the disclosed exemplary and / or illustrative embodiments, but, instead, the invention is defined by the appended claims. For example, the present invention can be practiced with many various materials and many various dimensions of all parts of the three-way valve, such as the many various materials and many various dimensions that are used in known valves for use in blood circulation systems.

Claims

Claims1. A pump-valve assembly for use in a blood circulation system, wherein:the pump -valve assembly comprises a pulsatile pump (4) and a three-way valve (5);the pulsatile pump comprises a pump chamber (6) for holding blood, wherein the pulsatile pump is controllably drivable to perform intake strokes and expel strokes, respectively, by controllably increasing and decreasing, respectively, the volume of the pump chamber for displacing blood into and out of the pump chamber, respectively; andthe three-way valve comprises a first port (21) which is configured to be connected to a blood supply line (7) for supplying blood to a patient, a second port (22) which is configured to be connected to a blood return line (8) for receiving blood from the patient, and a third port (23) which is connected or connectable to said pump chamber of the pulsatile pump via a blood pump line (9);characterized in that:the three-way valve (5) comprises a bifurcated Y-shaped conduit structure, which comprises a first conduit (1), a second conduit (2) and a third conduit (3), wherein each of the first conduit and the second conduit is branched off from the third conduit, and wherein said first port, said second port and said third port are ports of the first conduit, the second conduit and the third conduit, respectively;the first conduit (1) internally comprises a first check-valve (11, 31), which comprises a first check-valve seat (31), which is situated at a fixed location of the first conduit, and a first moveable check-valve body (41), which is moveably suspended relative to the first conduit, wherein the first check-valve seat is extending circumferentially around a first conduit center line (51) of the first conduit so as to circumferentially enclose a first check-valve passageway (61) of the first check-valve, and wherein the first moveable check-valve body is substantially shaped according to a first droplet-shape having a first droplet center line (71), and wherein the first moveable check-valve body along said first droplet center line has a first nose portion (81) and a first tail portion (91), which correspond to nose andtail portions of said first droplet-shape, respectively, wherein the first moveable check-valve body is facing with said first nose portion and said first tail portion to said third port and said first port, respectively, and wherein the first moveable check-valve body is reciprocally movable, relative to said first conduit, in opposite directions parallel to said first droplet center line and between:- a first closed position in which the first nose portion is sealingly lying against the first check-valve seat for preventing fluid flow through said first check-valve passageway in a direction from the first port to the third port, thereby defining a first closed condition of the first check-valve, and- a first open position in which the first nose portion is not lying against the first check-valve seat for allowing fluid flow through said first checkvalve passageway in a direction from the third port to the first port, thereby defining a first open condition of the first check-valve; andthe second conduit (2) internally comprises a second check-valve (12, 32), which comprises a second check-valve seat (32), which is situated at a fixed location of the second conduit, and a second moveable check-valve body (42), which is moveably suspended relative to the second conduit, wherein the second check-valve seat is extending circumferentially around a second conduit center line (52) of the second conduit so as to circumferentially enclose a second check-valve passageway (62) of the second check-valve, and wherein the second moveable check-valve body is substantially shaped according to a second droplet-shape having a second droplet center line, and wherein the second moveable check-valve body along said second droplet center line (72) has a second nose portion (82) and a second tail portion (92), which correspond to nose and tail portions of said second droplet-shape, respectively, wherein the second moveable check-valve body is facing with said second nose portion and said second tail portion to said second port and said third port, respectively, and wherein the second moveable check-valve body is reciprocally movable, relative to said second conduit, in opposite directions parallel to said second droplet center line between:- a second closed position in which the second nose portion is sealingly lying against the second check-valve seat for preventing fluid flow through said second check-valve passageway in a direction from the third port to thesecond port, thereby defining a second closed condition of the second checkvalve, and- a second open position in which the second nose portion is not lying against the second check-valve seat for allowing fluid flow through said second check-valve passageway in a direction from the second port to the third port, thereby defining a second open condition of the second checkvalve;whereby in an operation condition of the pump-valve assembly in which said first port is connected to said blood supply line, said second port is connected to said blood return line, and said third port is connected to said pulsatile pump via said blood pump line:- performing an expel stroke of the pulsatile pump causes the first checkvalve to be in said first open condition and causes the second check-valve to be in said second closed condition; and- performing an intake stroke of the pulsatile pump causes the second check-valve to be in said second open condition and causes the first checkvalve to be in said first closed condition.

2. The pump-valve assembly according to claim 1, wherein:a first exterior surface of the first tail portion (91) of the first moveable check-valve body (41) of the first check-valve (11, 31) has first recess structure (111) in deviation from said first droplet-shape according to which the first moveable check-valve body (41) is substantially shaped; and / ora second exterior surface of the second tail portion (92) of the second moveable check-valve body (42) of the second check-valve (12, 32) has second recess structure (112) in deviation from said second droplet-shape according to which the second moveable check-valve body (41) is substantially shaped.

3. The pump-valve assembly according to any one of the preceding claims, wherein:the first moveable check-valve body (41), together with first suspension means (121, 131) configured for moveably suspending the first moveable check-valve body (41) relative to the first conduit (1), are injection moulded as one first integral piece from a thermoplastic elastomer; and / orthe second moveable check-valve body (42), together with second suspension means (122, 132) configured for moveably suspending the second moveable check-valve body (42) relative to the second conduit (2), are injection moulded as one second integral piece from a thermoplastic elastomer.

4. The pump-valve assembly according to any one of the preceding claims, wherein:the first check-valve seat is formed by an inner wall surface of a section of the first conduit, wherein said section of the first conduit defines a fluid conducting space, which is locally narrowing towards said first check-valve passageway when considered in a direction from the first tail portion to the first head portion of the first moveable check-valve body; and / orthe second check-valve seat is formed by an inner wall surface of a section of the second conduit, wherein said section of the second conduit defines defines a fluid conducting space, which is locally narrowing towards said second check-valve passageway when considered in a direction from the second tail portion to the second head portion of the second moveable check-valve body.

5. The pump-valve assembly according to any one of the preceding claims, wherein a first bifurcation angle (101) of the bifurcated Y-shaped conduit structure is smaller than 60 degrees and a second bifurcation angle (102) of the bifurcated Y-shaped conduit structure is smaller than 60 degrees,wherein said first bifurcation angle (101) is defined as the largest occurring local acute angle of deflection between said first conduit center line (51) of the first conduit (1) and a third conduit center line (53) of the third conduit (3), and wherein said second bifurcation angle (102) is defined as the largest occurring local acute angle of deflection between said second conduit center line of the second conduit (2) and said third conduit center line of the third conduit (3).

6. The pump-valve assembly according to claim 5, wherein said first bifurcation angle (101) of the bifurcated Y-shaped conduit structure is smaller than50 degrees and said second bifurcation angle (102) of the bifurcated Y-shaped conduit structure is smaller than 50 degrees.

7. The pump-valve assembly according to claim 6, wherein said first bifurcation angle (101) of the bifurcated Y-shaped conduit structure is smaller than 40 degrees and said second bifurcation angle (102) of the bifurcated Y-shaped conduit structure is smaller than 40 degrees.

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