Device for extracorporeal blood treatment and device for the collection of blood clots in a direction of flow

Abstract

The invention relates to a device for the collection of blood clots in a direction of flow, the device being intended for a bloodline for delivering or evacuating blood to, respectively from, a blood treatment unit of an extracorporeal blood treatment device. The invention also relates to a device for extracorporeal blood treatment, and to a tubing set for use in a device for extracorporeal blood treatment.

Description

[0001] Device for extracorporeal blood treatment and device for flow-directed collection of blood clots

[0002] Technical area

[0003] The invention relates to a device for the flow-directed collection of blood clots for a blood line for supplying or removing blood to or from a blood treatment unit of an extracorporeal blood treatment device. Furthermore, the invention relates to a device for extracorporeal blood treatment and a tubing set for use in a device for extracorporeal blood treatment.

[0004] background

[0005] In chronic blood purification therapy procedures such as hemodialysis, hemofiltration, and hemodiafiltration, blood is pumped through an extracorporeal blood circuit. In hemodialysis, the blood to be treated flows through the blood chamber of a dialyzer divided by a semipermeable membrane into a blood chamber and a dialysis fluid chamber. In a dialysis fluid system, dialysis fluid flows through the dialysis fluid chamber of the dialyzer. The extracorporeal blood circuit has an arterial tubing leading to the blood chamber and a venous tubing branching off from the blood chamber. Known blood treatment devices have a blood pump, which is usually located upstream of the dialyzer's blood chamber, to ensure sufficient blood flow in the extracorporeal blood circuit.

[0006] The dialyzer used in extracorporeal blood treatment represents an insurmountable obstacle for clots due to the inner diameter of the hollow fibers of approximately 200 pm. Therefore, clots forming upstream of the dialyzer cannot reach the area downstream of the dialyzer and thus cannot reach the patient. However, blood clots located downstream of the dialyzer can be infused. In the blood treatment devices known from the prior art, blood clots that form in the blood on the way from the dialyzer to the patient are generally retained using a sieve-shaped device for capturing blood clots, which is provided downstream of the dialyzer in the venous blood line of the extracorporeal tubing system in front of the venous cannula. This sieve-shaped device is also called a blood clot catcher and is usually located at the bottom of the venous drip chamber, in which, among other things, air bubbles are collected from the blood.

[0007] However, during dialysis treatment, there may be reasons to reverse blood flow and pump blood back into the patient via the arterial access. Reasons for reversing blood flow include procedures to determine shunt flow or the reinfusion of blood remaining in the tubing at the end of a dialysis treatment.

[0008] However, if the blood pump's flow direction is reversed, for example, for a measurement to determine a hemodynamic parameter such as shunt flow, there is a risk that blood clots may enter the patient, even though the dialyzer retains blood clots forming upstream of the dialyzer. Experience has shown that blood clots accumulate at the dialyzer inlet during operation with "normal" blood flow. When the blood flow is reversed, these blood clots are then flushed toward the patient. To prevent the arterial reinfusion of blood clots, a sieve-shaped clot catcher, such as the one already used in the venous drip chamber, could be attached to the arterial end of the tubing set. However, this has the disadvantage of increased hydrodynamic resistance. Such a clot catcher can lead to additional blood clots during operation with a "normal" blood flow direction.There is therefore a need for a device for flow-directed collection of blood clots while simultaneously reducing flow resistance during treatment.

[0009] DE102017005535 discloses a device for flow-directed removal of blood clots with a movable sieve body.

[0010] Check valves with duckbill flaps for use in a flow path are known to those skilled in the art. Such duckbill valves allow free flow in a first direction in the flow path from a first to a second end of the valve, and prevent flow in the path in a second opposite direction. Such a duckbill valve comprises a cylindrical or conical valve body having a central longitudinal axis, an outer wall, and a pair of valve lips or flaps disposed at the second end of the valve, wherein the valve body and the lips or flaps are formed of a resilient material, and the flaps define an elongated, normally closed outlet opening of the valve at the second end.

[0011] The valve lips are a pair of flat inner surfaces that extend converging toward the second end.

[0012] Summary of the invention

[0013] As stated above, it is desirable to provide a device that prevents the infusion of blood clots during blood reinfusion, yet offers only low hydrodynamic resistance to the blood once it is withdrawn from a patient's arterial access for treatment, treated, and then pumped to their venous vascular access. The term 'flow-directed' in this context means that the desired effect is achieved only in one pumping or flow direction, while the effect is not achieved in the opposite pumping or flow direction. In the present invention, this means that blood clots are retained in one pumping or flow direction, while only low resistance is offered to blood flow in the opposite pumping or flow direction.

[0014] The invention is achieved by a device according to claim 1 and relates to a device for the flow-directed collection of blood clots, comprising a valve device (1) for defining a one-way flow, with at least one pair of lips (12a, 12b) arranged in a converging relationship, each lip having a lip base end (13) and a lip outer end (14), and wherein the lip base ends (13) form part of an open valve bottom end (15) and the outer ends of the lip are arranged side by side and form a slot (17), the valve further comprising a flange (16) extending outwards at the end of the valve bottom end, characterized in that at least one of the lips (12a, 12b) is provided with a toothed sealing edge (20) and a fluid-permeable region (30) is formed.

[0015] Further embodiments are the subject of the dependent claims.

[0016] One embodiment of the present invention relates to a device for the flow-directed collection of blood clots, comprising a valve device (1) for defining a one-way flow, wherein both opposite lips of the valve device are each provided with a toothed sealing edge.

[0017] The serrated sealing edge can have different tooth shapes. In one embodiment, the sealing edge formed by at least one of the two lips of the valve device can have teeth in the shape of triangular tips or be wave-shaped or sinusoidal.

[0018] The size of the openings in the fluid-permeable area can be adjusted to specific requirements to retain blood clots above a certain size in a flow-directed manner. From a medical perspective, clots larger than 1 mm should be retained, as these can lead to embolism. The fluid-permeable area formed by the two lips of the valve device at the serrated sealing edge can have openings with a maximum size of 0.5 mm, preferably 0.1 to 0.25 mm.

[0019] An embodiment of the present invention relates to a device for flow-directed collection of blood clots comprising a valve device for defining a one-way flow, characterized in that each lip is provided with one or more fold lines (18) which run substantially in a straight line across the surface of the lip from the end of the lip base towards the slit.

[0020] Another embodiment relates to a device for flow-directed collection of blood clots, comprising a valve device for establishing a one-way flow, with two pairs of lips (12a, 12b and 12c, 12d) arranged in a converging relationship, wherein the lip pairs are arranged in a cross shape, preferably at an angle of 90° to each other, and form a fluid-permeable region (30). In this embodiment, all lips can have a serrated region and form a fluid-permeable region. In a further embodiment, only one opposing pair of lips forms a fluid-permeable region, while the second pair of lips has no fluid-permeable region.

[0021] In a preferred embodiment of the present invention, the valve device is designed in one piece.

[0022] In one embodiment of the present invention, the device may comprise at least one or more openings, wherein the openings have a maximum size of 0.5 mm, preferably 0.1 to 0.25 mm. The shape of the openings may be round, square, or slit-shaped. The openings may be provided at any point on the valve lips. They are preferably located near the end of the valve base. Blood can also flow back through these to prevent the formation of dead or stagnant zones in the area of ​​the valve base.

[0023] The valve device of the present invention can be made of a thermoplastic elastomer (TPE or TPR) or a medical-grade and food-grade silicone or fluorosilicone rubber. Examples of medical-grade silicones include methyl silicone, vinyl-methyl silicone, phenyl-vinyl-methyl silicone, phenyl-modified silicone, fluoroalkyl silicone, or fluoro-vinyl-methyl silicone.

[0024] A further possible embodiment of the present invention relates to a device for the flow-directed collection of blood clots with a valve device in which the sealing lip is designed in the shape of a cross and at least one of the sealing edges has a toothed edge.

[0025] The invention further relates to a blood tubing set comprising a device for flow-directed collection of blood clots with a valve device as disclosed here.

[0026] Furthermore, the present invention relates to a device for extracorporeal blood treatment, such as a hemodialysis machine, a machine for therapeutic apheresis or for extracorporeal membrane oxygenation (ECMO), with a blood tubing set comprising a device for flow-directed collection of blood clots with a valve device as disclosed here.

[0027] Brief description of the drawings

[0028] Figure 1 shows a conventional venous drip chamber (2) with an inlet with a laterally arranged inlet (3) and an outlet (5) and a clot catcher (4).

[0029] Figure 2 shows a valve device (1) for defining a one-way flow, comprising a pair of lips (12a, 12b) arranged in a converging relationship, each lip having a lip base end (13) and a lip outer end (14), and wherein the lip base ends (13) form part of an open valve bottom end (15) and the outer ends of the lip are arranged side by side and form a slot (17), the valve further comprising a flange (16) extending outwardly at the end of the valve bottom end. One of the two lips (12a, 12b) is provided with a serrated sealing edge (20) so that a fluid-permeable region (30) is created. Figure 2 also shows a fold line (18) extending substantially in a straight line across the surface of the lip from the end of the lip base towards the slot.

[0030] Figure 3 shows a further embodiment of the valve device (1) for defining a one-way flow, comprising a pair of lips (12a, 12b) arranged in a converging relationship, each lip having a lip base end (13) and a lip outer end (14), and wherein the lip base ends (13) form part of an open valve bottom end (15) and the outer ends of the lip are arranged side by side and form a slot (17), the valve further comprising a flange (16) extending outwardly at the end of the valve bottom end. In the embodiment shown in Figure 3, both lips (12a, 12b) have a serrated sealing edge (20) so that a fluid-permeable region (30) is created. Figure 3 also shows a fold line (18) which runs essentially in a straight line across the surface of the lip from the end of the lip base towards the slot.

[0031] Figure 4 shows a further embodiment of the device for flow-directed collection of blood clots comprising a valve device (1) for defining a one-way flow, with two pairs of lips (12a, 12b and 12c, 12d) arranged in a converging relationship, wherein the pairs of lips are arranged crosswise, preferably at an angle of 90° to each other, and form a fluid-permeable region (30).

[0032] In the embodiment shown in Figure 4, one or more substantially straight lines (18) run along each lip base end and each lip (12) is provided with one or more fold lines (18) running across the surface of the lip from the end of the lip base towards the slit.

[0033] Figure 5 shows a further embodiment of the valve device (1) shown in Figure 3 for defining a one-way flow, comprising a pair of lips (12a, 12b) arranged in a converging relationship, each lip having a lip base end (13) and a lip outer end (14), and wherein the lip base ends (13) form part of an open valve bottom end (15) and the outer ends of the lip are arranged side by side to form a slot (17), the valve further comprising a flange (16) extending outwardly at the end of the valve bottom end. In the embodiment shown in Figure 3, both lips (12a, 12b) have a serrated sealing edge (20) so that a fluid-permeable region (30) is created. In addition, the valve device comprises one or more openings (40). The openings 40 may have a diameter of less than 1 mm, preferably in the range of 0.1 to 0.5 mm.

[0034] Figure 6 shows a further embodiment of the device for flow-directed collection of blood clots shown in Figure 4, comprising a valve device (1) for establishing a one-way flow, with two pairs of lips (12a, 12b and 12c, 12d) arranged in a converging relationship, wherein the lip pairs are arranged crosswise, preferably at an angle of 90° to one another, and form a fluid-permeable region (30). In addition, the valve device shown in Figure 6 comprises one or more openings (40). The openings 40 can have a diameter of less than 1 mm, preferably in the range of 0.1 to 0.5 mm, and can be fluid-permeable in both flow directions.

[0035] Figures 7a and 7b show a housing (70) for accommodating one of the devices (1) shown in Figures 2 to 6 for the flow-directed collection of blood clots. The housing (70) comprises a supply line 71 and a discharge line (73) suitable for connection to a tubing set, as well as a housing body (72) suitable for accommodating the device (1). Furthermore, Figures 7a and 7b show the operation of the device (1) for the different flow directions of the patient's blood.

[0036] Figure 7a shows a housing (70) with a device (1) for flow-directed collection of blood clots. The flow direction (50) of the patient's blood runs from the arterial to the venous access. This is the predominant flow direction during extracorporeal blood treatment. The valve lips 12a and 12b of the device (1) are open and offer only minimal resistance to the fluid flow.

[0037] Figure 7b shows a housing (70) with a device (1) for the flow-directed collection of blood clots. The flow direction (50) of the patient's blood runs in the opposite direction, i.e., from the venous to the arterial access. The valve lips 12a and 12b of the device (1) are closed, so that a fluid-permeable area (30) is present at the serrated sealing edge (20). Blood clots (60) are retained by the device (1), while blood and other fluids can flow back. In addition, the valve device (1) comprises one or more openings (40). Blood can also flow back through these openings to prevent the formation of so-called dead or stagnation zones in the area of ​​the valve base.

[0038] List of reference symbols

[0039] 1 device

[0040] 2 venous drip combs

[0041] 3 Inlet

[0042] 4 clot traps

[0043] 5 Outlet

[0044] 12, 12a, 12b, 12c, 12d lips

[0045] 13 Lip base end

[0046] 14 Outer lip end

[0047] 15 Valve base end

[0048] 16 flange

[0049] 17 Slot

[0050] 18 fold line

[0051] 20 Sealing edge

[0052] 30 fluid-permeable area

[0053] 40 Opening

[0054] 50 Flow direction

[0055] 60 blood clots

[0056] 70 housings

[0057] 71 supply line

[0058] 72 housing bodies

[0059] 73 Derivation

Claims

Patent claims 1. Device for the flow-directed collection of blood clots comprising a valve device (1) for establishing a one-way flow, wherein the valve device is designed as a check valve and comprises fluid-permeable regions in the blocking direction.

2. A device for flow-directed collection of blood clots comprising a valve device (1) for defining a one-way flow, with at least one pair of lips (12a, 12b) arranged in a converging relationship, each lip having a lip base end (13) and a lip outer end (14), and wherein the lip base ends (13) form part of an open valve bottom end (15) and the outer ends of the lip are arranged side by side and form a slot (17), the valve further comprising a flange (16) extending outwards at the end of the valve bottom end, characterized in that at least one lip (12a, 12b) is provided with a toothed sealing edge (20) and a fluid-permeable region (30) is formed.

3. Device according to claim 1, characterized in that both lips (12a, 12b) of the valve device are provided with a toothed sealing edge.

4. Device according to claim 1 to 2, characterized in that the toothed sealing edge (20) formed by at least one of the two lips of the valve device has teeth in the form of triangular tips or the sealing edge (20) is wave-shaped or sinusoidal.

5. Device according to claim 1 to 3, characterized in that the toothed sealing edge (20) formed by both lips of the valve device has openings with a size of maximum 0.5 mm, preferably 0.1 to 0.25 mm.

6. Device according to one of claims 1 to 4, characterized in that each lip base end is provided along one or more substantially straight lines (18) and each lip (12) is provided with one or more fold lines (18) which run across the surface of the lip from the end of the lip base towards the slit.

7. A device for flow-directed collection of blood clots comprising a valve device (1) for establishing a one-way flow, with two pairs of lips (12a, 12b and 12c, 12d) arranged in a converging relationship, wherein the pairs of lips are arranged crosswise, preferably at an angle of 90° to each other, and form a fluid-permeable region (30).

8. Device according to one of the preceding claims, wherein the valve device (1) comprises at least one or more openings (40), wherein the openings (40) have a size of at most 0.5 mm, preferably 0.1 to 0.25 mm.

9. Device according to one of the preceding claims, characterized in that the valve device (1) consists of an elastomeric material, preferably a substituted or unsubstituted silicone or a thermoplastic elastomer.

10. Device according to one of the preceding claims, characterized in that the valve device (1) is designed in one piece.

11. Housing (70) comprising a device (1) according to one of the preceding claims.

12. A blood tubing set comprising a device for flow-directed collection of blood clots according to any one of claims 1 to 10.

13. Device for extracorporeal blood treatment comprising a blood tubing set according to claim 12 or a device for flow-directed collection of blood clots according to one of claims 1 to

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