Extracorporeal circulation circuit

Abstract

To make it possible to realize an extracorporeal circulation circuit in which damage to blood cells due to driving of a pump is less likely to occur.SOLUTION: An extracorporeal circulation circuit 100 includes: a pump tube 101 that is attached to a roller pump for drawing blood from a patient; an upstream line 103 provided on an upstream side of the pump tube 101; and a downstream line 105 provided on a downstream side thereof. At least one of the upstream and downstream sides of the pump tube 101 is provided with a check valve 107 that suppresses backflow of blood toward the upstream side.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an extracorporeal circulation circuit, and more particularly to an extracorporeal circulation circuit having a pump tube attached to a roller pump. [Background technology]

[0002] Extracorporeal circulation circuits used in extracorporeal circulation treatments such as dialysis are equipped with a pump tube attached to a roller pump. By rotating the pump tube with the rollers of the roller pump, blood can be extracted from the patient and sent to a dialysis machine or other device.

[0003] A typical roller pump has a housing that houses a U-shaped pump tube and a rotating rotor located in the center of the housing. The rotor has multiple rollers attached to its outer edge that contact and press against the pump tube. By rotating the rotor, the position at which the rollers contact the pump tube moves from the upstream side to the downstream side. This causes blood to be pushed out of the pump tube downstream of the rollers, and blood to be drawn up from the patient's blood vessels upstream of the rollers (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-033663 Summary of the Invention [Problem to be solved by the invention]

[0005] The roller contacts the U-shaped pump tube near its upstream end and moves to the downstream end while pressing against the pump tube, then separates from it. The pressure is higher downstream of the part of the pump tube pressed by the roller, and lower upstream. When the roller separates from the pump tube, the high-pressure area downstream of the roller and the low-pressure area upstream communicate with each other, potentially causing backflow, where blood flows backward from the downstream side to the upstream side. In recent years, blood flow rates have been increased to improve dialysis efficiency, making backflow more likely. Large backflow can potentially lead to blood cell damage and reduced actual blood flow, resulting in reduced dialysis efficiency.

[0006] An object of the present disclosure is to realize an extracorporeal circulation circuit in which blood cells are less likely to be damaged by pump operation. [Means for solving the problem]

[0007] One aspect of the extracorporeal circulation circuit of the present disclosure includes a pump tube attached to a roller pump that draws blood from a patient, lines connected to the upstream and downstream sides of the pump tube, and a check valve provided on at least one of the upstream and downstream sides of the pump tube to prevent backflow of blood to the upstream side.

[0008] One aspect of the extracorporeal circulation circuit is equipped with a check valve that prevents blood from flowing backward upstream, thereby reducing the occurrence of large backflows and preventing situations that could damage blood cells or reduce dialysis efficiency.

[0009] In one aspect of the extracorporeal circulation circuit, the circuit may further include tube connection joints that connect the pump tube to the upstream and downstream lines, and the check valve may be incorporated into at least one of the tube connection joints. This configuration allows the check valve to be located close to the pump tube, thereby minimizing the impact of backflow on dialysis efficiency.

[0010] In one embodiment of the extracorporeal circuit, the check valve can be provided upstream of the pump tube, which can further reduce the impact of backflow on the patient.

[0011] In one aspect of the extracorporeal circuit, the upstream line has a branch line, and the check valve can be provided between the branch line and the pump tube. With this configuration, the check valve can be less likely to affect a pressure measuring device or the like provided at the end of the branch line.

[0012] In one aspect of the extracorporeal circuit, the downstream line has a bubble removal chamber, and the check valve can be provided between the bubble removal chamber and the pump tube. By providing a check valve between the bubble removal chamber and the pump tube, the impact of backflow on the patient can also be reduced.

[0013] In one embodiment of the extracorporeal circuit, the check valve may be a duckbill valve, which is easy to install and has an excellent effect of reducing the influence of backflow.

[0014] One embodiment of the extracorporeal circulation circuit can be installed in a dialysis monitoring device that detects blood leakage based on the amount of hemoglobin on the secondary side of the dialyzer to which the downstream line is connected. Hemoglobin leaked out due to damage to blood cells may flow to the secondary side of the dialyzer and cause the blood leakage sensor to malfunction. By installing an extracorporeal circulation circuit that is less likely to damage blood cells in the dialysis monitoring device, it is possible to make the blood leakage sensor less likely to malfunction. [Effects of the Invention]

[0015] According to the extracorporeal circulation circuit of the present disclosure, damage to blood cells caused by pump operation can be reduced. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic diagram showing an extracorporeal circulation circuit according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] As shown in FIG. 1, an extracorporeal circulation circuit 100 according to one embodiment includes a pump tube 101 attached to a roller pump, an upstream line 103 connected to the upstream side of the pump tube, and a downstream line 105 connected to the downstream side.

[0018] The upstream line 103 has a tube that connects the patient's blood removal port to the pump tube 101. The downstream line 105 has a tube that connects the pump tube 101 to a medical device such as a dialyzer. The tubes of the upstream line 103 and the downstream line 105 have smaller inner and outer diameters than the pump tube 101. The upstream line 103 and the downstream line 105 may have one or more branch lines connected to them midway through the flow path, or may include components other than tubes, such as a bubble removal chamber or a pillow.

[0019] The upstream end of the pump tube 101 and the downstream end of the tube of the upstream line 103 are connected by a tube connection joint 111 that connects tubes of different diameters. The downstream end of the pump tube 101 and the upstream end of the tube of the downstream line 105 are connected by a downstream tube connection joint 112. A check valve 107 is provided inside the upstream tube connection joint 111.

[0020] In this embodiment, the check valve 107 does not have a significant effect on the flow of blood from the upstream side to the downstream side, but it does regulate the flow of blood from the upstream side to the downstream side. Therefore, even if the operation of the roller pump repeatedly generates positive pressure areas and negative pressure areas and the two areas communicate with each other within the pump tube 101, it is possible to make it difficult for backflow from the downstream side to occur.

[0021] The check valve 107 can have various configurations that allow liquid to flow in one direction and restrict flow in the opposite direction, and can be, for example, a duckbill valve or umbrella valve made of elastomer such as rubber. Among these, a duckbill valve is preferable because it can be easily housed inside the upstream tube connection joint 111 and can reduce pressure loss.

[0022] By providing the check valve 107 inside the upstream tube connection joint 111, a separate housing for accommodating the check valve 107 is not required, thereby reducing the number of parts. Furthermore, the check valve 107 can be located closer to the pump tube 101, where positive and negative pressure portions are generated. By locating the check valve 107 closer to the pump tube 101, pressure changes are immediately reflected and the check valve 107 quickly opens and closes, preventing blood flow from stagnation and suppressing blood coagulation. However, the effect of preventing backflow can be achieved by providing the check valve 107 at any location on the flow path between the patient's blood removal port and the pump tube 101. If the upstream line 103 has various branch lines, it is preferable to provide the check valve 107 closer to the pump tube 101 than the most downstream branch line in the upstream line 103, in order to prevent backflow due to these branch lines serving as pressure escape routes. Furthermore, if there are components with large volumes, such as a bubble removal chamber or pillow, between the pump tube 101 and the check valve 107, these components may be deformed by pressure changes, causing backflow even when the check valve 107 is closed. For this reason, it is preferable to provide the check valve closer to the pump tube 101 than these components.

[0023] The effect of suppressing backflow can also be obtained when the check valve 107 is provided downstream of the pump tube 101. For example, the check valve 107 can be provided inside the downstream tube connection joint 112. Alternatively, the check valve 107 can be provided midway along the flow path of the downstream line 105. If the downstream line 105 has branch lines, it is preferable to provide the check valve 107 closer to the pump tube 101 than the most upstream branch line. Furthermore, if the downstream line 105 has components with large volumes, such as a bubble removal chamber or a pillow, it is preferable to provide the check valve closer to the pump tube 101 than these components.

[0024] Whether the check valve 107 is provided upstream or downstream of the pump tube, the closer it is to the pump tube, the less the impact of backflow on dialysis efficiency it can be, so it is preferably provided between the pump tube and the first branch line upstream or downstream of the pump tube.It is more preferable to incorporate the check valve in the joint connecting the pump tube and the line tube, as this can further reduce the impact of backflow on dialysis efficiency and reduce the number of parts.

[0025] When the check valve 107 is provided in the upstream tube connection joint 111 and the downstream tube connection joint 112, for example, a flange can be provided inside the tube connection joint, and the check valve 107 can be sandwiched between the flange and the line tube or the pump tube. Alternatively, the tube connection joint can be separated into, for example, a first part on the pump tube side and a second part on the line tube side, and the check valve can be sandwiched between the first part and the second part. Alternatively, the tube connection joint can be separated into two halves, and the two parts can be assembled with the valve member sandwiched between them.

[0026] When the check valve 107 is provided in a location other than the upstream tube connection joint 111 and the downstream tube connection joint 112, a housing containing the check valve 107 can be inserted midway through the tube of the upstream line 103 or the downstream line 105. The check valve can also be provided inside a branch connector or the like provided in the upstream line 103 or the downstream line 105.

[0027] If damage to the hollow fiber membrane or breakage of the seal occurs in a dialyzer, causing communication between the primary side (where blood flows) and the secondary side (where dialysate flows), not only will dialysis not function properly, but endotoxins or bacteria from the dialysate side may be introduced into the blood side, potentially causing the patient to go into shock. For this reason, some dialysis monitoring devices measure the amount of hemoglobin in the secondary side and issue a blood leakage alarm. While hemolysis detection using hemoglobin is simple and highly sensitive, if hemolysis occurs in the primary side, hemoglobin will permeate the hollow fiber membrane and leak into the secondary side, resulting in a blood leakage even if the dialyzer is functioning normally. Furthermore, there is no easy way to determine whether the alarm is due to hemolysis or damage to the dialyzer. Therefore, when an alarm is issued, even if the dialyzer is not actually damaged, it is necessary to replace the dialyzer and the connected extracorporeal circulation circuit as a safety measure and restart the dialysis. This not only consumes a lot of time, effort, and money, but also places a significant burden on the patient.

[0028] The extracorporeal circulation circuit 100 of this embodiment, which has a check valve 107, is less likely to cause hemolysis due to backflow, and is therefore preferable because it can reduce the occurrence of false alarms about blood leakage when installed in a dialysis monitoring device that detects blood leakage based on the amount of hemoglobin on the secondary side. [Industrial Applicability]

[0029] The extracorporeal circulation circuit of the present disclosure is less likely to cause damage to blood cells due to pump operation, and is therefore useful in the medical field. [Explanation of symbols]

[0030] 100 Extracorporeal circulation circuit 101 Pump Tube 103 Upstream Line 105 Downstream Line 107 Check valve 111 Tube connection fitting 112 Tube connection fitting

Claims

1. a pump tubing attached to a roller pump that draws blood from the patient; lines connected to the upstream and downstream sides of the pump tube, respectively; The extracorporeal circuit further comprises a check valve provided on at least one of the upstream and downstream sides of the pump tube to prevent backflow of blood to the upstream side.

2. The pump further includes tube connection joints for connecting the pump tube to the upstream and downstream lines, The extracorporeal circuit according to claim 1 , wherein the check valve is incorporated into at least one of the tube connection joints.

3. The extracorporeal circuit according to claim 1 , wherein the check valve is provided upstream of the pump tube.

4. the upstream line has a branch line; The extracorporeal circulation circuit according to claim 3 , wherein the check valve is provided between the branch line and the pump tube.

5. the downstream line has a bubble removal chamber; The extracorporeal circulation circuit according to claim 1 , wherein the check valve is provided between the bubble removal chamber and the pump tube.

6. The extracorporeal circuit according to claim 1 , wherein the check valve is a duckbill valve.

7. The extracorporeal circuit according to any one of claims 1 to 6, which is assembled to a dialysis monitoring device that detects blood leakage based on the amount of hemoglobin on the secondary side of a dialyzer to which the downstream line is connected.

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