Blood purification device and control method thereof

Abstract

To eliminate complicated manual work during plasma collection and achieve simplification of the device configuration in a blood purification device that includes a first blood purifier and a second blood purifier and is configured to collect plasma present in a region on the upstream of the second blood purifier.SOLUTION: A blood purification device includes: a pump 40 which is provided in an intermediate circuit 30 connecting a first blood purifier 10 and a second blood purifier 20, and transfers filtrate; an air supply unit 60 which is provided in an air supply line 50 connected to the first blood purifier 10; a bypass circuit 70 which bypasses the second blood purifier 20; a flow path changing unit which changes the flow path of the filtrate to cause the filtrate to flow into either the second blood purifier 20 or the bypass circuit 70; and a control unit 80 which performs control to circulate the filtrate via the intermediate circuit 30 and the bypass circuit 70 by operating the air supply unit 60 to supply air into the air supply line 50, operating the pump 40, and controlling the flow path changing unit.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a blood purification device and a control method thereof.

Background Art

[0002] Conventionally, blood purification treatment has been carried out in which blood is taken out from a patient's body, pathogenic substances, specific white blood cells, etc. are removed from this blood, and then the blood is returned to the body. In such blood purification treatment, a blood purification device is used that includes a blood circuit for circulating the blood taken out from the body and returning it to the body, and a blood purifier having a treatment material such as an adsorbent or a separation material for removing and separating specific substances.

[0003] In recent years, a blood purification device including a plurality of blood purifiers has been proposed. For example, a plasma separator (first blood purifier) that generates a filtrate containing plasma by filtering blood, and a plasma component separator (second blood purifier) that further filters the filtrate supplied from the plasma separator and separates it into low-molecular-weight plasma components and high-molecular-weight plasma components, and a blood purification device configured to return the plasma remaining in the device after blood purification to the body by supplying air using a dummy tube that is a temporary air supply path has been proposed (see Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the conventional blood purification device as described in Patent Document 1, when recovering plasma, manual operations such as clamping the primary side inlets and outlets of the plasma separator with forceps and replacing them with dummy tubes are required, which increases the user's workload. In addition, since the dummy tube of the blood purification device of Patent Document 1 is for supplying air, there is also a problem that it cannot be used as a plasma bypass flow path (a flow path for circulating the plasma to be recovered) even when the plasma separator becomes clogged.

[0006] The present invention has been made in view of such circumstances, and in a blood purification device including a first blood purifier and a second blood purifier and configured to recover plasma existing in a region upstream of the second blood purifier, an object is to omit complicated manual operations during plasma recovery and to simplify the device configuration.

Means for Solving the Problems

[0007] To achieve the above object, a blood purification device according to the present invention includes a first blood purifier that generates a filtrate containing plasma by filtering blood, a second blood purifier that further filters the filtrate supplied from the first blood purifier or adsorbs plasma contained in the filtrate to generate a return liquid, a pump provided in an intermediate circuit connecting the first blood purifier and the second blood purifier for transporting the filtrate from the first blood purifier toward the second blood purifier, an air supply path connected to a port of the first blood purifier to which the intermediate circuit is not connected, an air supply unit provided in the air supply path, a bypass circuit that bypasses the second blood purifier, a flow path changing unit that changes the flow path of the filtrate so that the filtrate flows into either the second blood purifier or the bypass circuit, and a control unit that controls the air supply unit to supply air to the air supply path, operates the pump, and controls the flow path changing unit to circulate the filtrate through the intermediate circuit and the bypass circuit.

[0008] Further, the control method according to the present invention includes a first blood purifier that generates a filtrate containing plasma by filtering blood, a second blood purifier that further filters the filtrate supplied from the first blood purifier or adsorbs the plasma contained in the filtrate to generate a return liquid, a pump provided in an intermediate circuit connecting the first blood purifier and the second blood purifier for transporting the filtrate from the first blood purifier toward the second blood purifier, an air supply passage connected to a port of the first blood purifier where the intermediate circuit is not connected, an air supply unit provided in the air supply passage, a bypass circuit that bypasses the second blood purifier, a flow path changing unit that changes the flow path of the filtrate so that the filtrate flows into either the second blood purifier or the bypass circuit, and a control unit. The control method of the blood purification device includes a control step in which the control unit operates the air supply unit to supply air to the air supply passage, operates the pump, and controls the flow path changing unit to circulate the filtrate through the intermediate circuit and the bypass circuit.

[0009] When such a configuration and method are adopted, there are provided a pump provided in an intermediate circuit connecting the first blood purifier and the second blood purifier for transporting the filtrate, an air supply unit provided in an air supply passage connected to a port of the first blood purifier where the intermediate circuit is not connected, a bypass circuit that bypasses the second blood purifier, and a flow path changing unit that changes the flow path of the filtrate. When clogging occurs in the second blood purifier, the control unit operates the air supply unit to supply air to the air supply passage, operates the pump, and controls the flow path changing unit to circulate the filtrate through the intermediate circuit and the bypass circuit, so that the filtrate can be recovered. Therefore, when recovering the filtrate existing in the region upstream of the second blood purifier, there is no need to attach a dummy tube or perform a clamp operation, so the work burden on the user can be reduced. In addition, since the flow path connected to the existing filtration pressure port can be used as the air supply passage, there is no need to newly add a flow path for air supply, and the device configuration is simplified.

[0010] In the blood purification device according to the present invention, a flow path changing unit having a first control valve provided in a flow path connected to the outlet of a second blood purifier and a second control valve provided on a bypass circuit is employed, and a control unit for controlling the first control valve and the second control valve can be employed. In such a case, when, for example, the membrane pressure of the second blood purifier exceeds a predetermined threshold value, the control unit operates the air supply unit to supply air to the air supply path, operates the pump, and closes the first control valve while opening the second control valve, whereby the filtrate can be made to flow into the bypass circuit.

[0011] By adopting such a configuration, the control unit controls two types of control valves (the first control valve provided in the flow path connected to the outlet of the second blood purifier and the second control valve provided on the bypass circuit), whereby the flow path can be changed. That is, by opening the first control valve and closing the second control valve with the control unit, the filtrate can be made to flow into the second blood purifier, while by opening the second control valve and closing the first control valve with the control unit, the filtrate can be made to flow into the bypass circuit.

[0012] In the blood purification device according to the present invention, a pressure measurement unit for measuring the in-line pressure of an intermediate circuit between a pump and a second blood purifier is employed, and a control unit for controlling the flow path changing unit based on the value of the in-line pressure measured by the pressure measurement unit can be employed. In such a case, when the value of the pressure measured by the pressure measurement unit exceeds a predetermined threshold value, the control unit operates the air supply unit to supply air to the air supply path, operates the pump, and controls the flow path changing unit, whereby control can be implemented to make the filtrate flow through the intermediate circuit and the bypass circuit.

[0013] When adopting such a configuration, the control unit can control the flow path changing unit based on the value of the in-line pressure measured by the pressure measuring unit (the value of the in-line pressure between the pump and the second blood purifier in the intermediate circuit connecting the first blood purifier and the second blood purifier). For example, when the value of the in-line pressure measured by the pressure measuring unit is less than a predetermined threshold value, the control unit determines that there is no clogging in the second blood purifier, and controls the flow path changing unit to allow the filtrate to flow into the second blood purifier. On the other hand, when the value of the in-line pressure measured by the pressure measuring unit exceeds the predetermined threshold value, the control unit determines that there is clogging in the second blood purifier, and can control the flow path changing unit to allow the filtrate to flow into the bypass circuit.

[0014] In the blood purification device according to the present invention, a waste line for discarding the liquid flowing into the bypass circuit can be further provided.

[0015] When adopting such a configuration, for example, the liquid used for cleaning the first blood purifier (the liquid containing the filter filling liquid and unnecessary components) can be discarded via the bypass circuit and the waste line without passing through the second blood purifier.

Effect of the Invention

[0016] According to the present invention, in a blood purification device including a first blood purifier and a second blood purifier and configured to recover plasma existing in a region upstream of the second blood purifier, it is possible to omit complicated manual operations during plasma recovery and simplify the device configuration.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0018] Hereinafter, each embodiment of the present invention will be described with reference to the drawings.

[0019] <First Embodiment> First, the configuration of the blood purification device 1 according to the first embodiment of the present invention will be described. The blood purification device 1 according to the present embodiment is used for so-called double filtration plasma pheresis (DFPP).

[0020] As shown in FIG. 1, the blood purification device 1 according to the present embodiment includes a blood collection circuit 2, a blood return circuit 3, a first blood purifier 10, a second blood purifier 20, an intermediate circuit 30, a pump 40, a control unit 80, etc. By driving the pump 40 in the forward direction by the control unit 80, the blood collected through the blood collection circuit 2 is configured to pass through the first blood purifier 10 and the second blood purifier 20 and return through the blood return circuit 3.

[0021] Also, as shown in FIG. 1, the blood purification device 1 according to the present embodiment includes an air supply unit 60 capable of supplying air to an air supply point 51 in an air supply path 50 connected to the first blood purifier 10, a bypass circuit 70 that bypasses the second blood purifier 20, and a flow path changing unit that changes the flow path of the filtrate so that the filtrate flows into either the second blood purifier 20 or the bypass circuit 70. By operating the air supply unit 60 by the control unit 80 to supply air to the air supply path 50, operating the pump 40, and controlling the flow path changing unit, control is implemented to allow the filtrate to flow through the intermediate circuit 30 and the bypass circuit 70, so that plasma recovery can be performed.

[0022] In the first blood purifier 10 in this embodiment, by filtering the blood of patient P introduced through the blood introduction section 2a and the blood collection circuit 2 by a blood collection pump (not shown), it functions to generate a filtrate containing plasma. In this embodiment, a plasma separator in which a filtration membrane for separating blood into blood cells and plasma is built into a cylindrical housing is employed as the first blood purifier 10. In order to promote such separation, a structure (such as a gas-liquid separator or an air valve) for increasing the internal pressure of the blood collection circuit 2 may be provided.

[0023] As shown in FIG. 1, the first blood purifier 10 has a blood inflow port 11 for allowing blood to flow in, a blood cell outflow port 12 for allowing the blood cell components separated from the plasma by the filtration membrane to flow out, a filtrate outflow port 13 for allowing the plasma components (filtrate) separated from the blood cells by the filtration membrane to flow out, and an air supply port 14. The blood inflow port 11 and the blood cell outflow port 12 communicate with the space inside the filtration membrane of the first blood purifier 10. On the other hand, the filtrate outflow port 13 and the air supply port 14 communicate with the space outside the filtration membrane of the first blood purifier 10.

[0024] As shown in FIG. 1, an air supply passage 50 is connected to the air supply port 14 of the first blood purifier 10. And an air supply section 60 capable of supplying air is connected to an air supply location 51 arranged in the air supply passage 50. By driving and controlling the air supply section 60 with the control section 80, air can be supplied to the space outside the filtration membrane of the first blood purifier 10 through the air supply location 51, the air supply passage 50, and the air supply port 14, and "bypass recovery control" described later can be realized. Note that the air supply section 60 can be realized by various known methods such as being composed of a pump for sending air into the circuit and a valve provided between the pump and the circuit, and the detailed configuration is omitted from the illustration.

[0025] The second blood purifier 20 in the present embodiment functions to generate a return fluid by further filtering the filtrate supplied from the first blood purifier 10 via the intermediate circuit 30. In the present embodiment, a plasma component separator in which a filtration membrane that separates the filtrate into low-molecular-weight plasma components and high-molecular-weight plasma components is built into a cylindrical housing is employed as the second blood purifier 20.

[0026] As shown in FIG. 1, the second blood purifier 20 has a filtrate inflow port 21 for allowing the filtrate to flow in, a discharge port 22 for discharging high-molecular-weight plasma components (including causative substances, etc.) separated from the low-molecular-weight plasma by the filtration membrane, a return fluid outflow port 23 for allowing the low-molecular-weight plasma components (return fluid) separated from the high-molecular-weight plasma components by the filtration membrane to flow out, and a liquid supply port 24 to which a liquid (physiological saline or replenishing fluid) stored in the container 90 is supplied. The filtrate inflow port 21 and the discharge port 22 communicate with the space inside the filtration membrane of the second blood purifier 20. On the other hand, the return fluid outflow port 23 and the liquid supply port 24 communicate with the space outside the filtration membrane of the second blood purifier 20.

[0027] The high-molecular-weight plasma components discharged from the discharge port 22 via the discharge line 25 can be discarded as they are, or can be returned to the intermediate circuit 30 via a circulation circuit (not shown), mixed with the filtrate, and then re-introduced into the filtrate inflow port 21 of the second blood purifier 20 and processed again by the filtration membrane. The return fluid (low-molecular-weight plasma components) flowing out from the return fluid outflow port 23 is conveyed to the blood return circuit 3 via the return fluid circuit 4 as shown in FIG. 1, mixed with the blood cell components flowing out from the blood cell outflow port 12 of the first blood purifier 10, and then returned to the patient P via the blood lead-out portion 3a. The bag connection line 5 connects the liquid supply port 24 and the return fluid circuit 4 to the container 90. The bag connection line 5 is provided with a liquid pump 6, a liquid control valve 5a, and a bypass control valve 71a.

[0028] An outflow control valve 25a and a return fluid circuit 4a controlled by a control unit 80 are provided in a discharge line 25 connected to a discharge port 22 and a return fluid outflow port 23, respectively. When the second blood purifier 20 is not clogged during treatment and plasma collection, the outflow control valve 4a is opened (at this time, the liquid control valve 5a and the outflow control valve 25a are closed), and the discharge of low molecular weight plasma components from the return fluid outflow port 23 is permitted. On the other hand, when the second blood purifier 20 becomes clogged during treatment, the outflow control valve 25a is opened (at this time, the liquid control valve 5a and the outflow control valve 4a are closed), and the discharge of high molecular weight plasma components from the discharge port 22 is permitted. Further, when the second blood purifier 20 becomes clogged during plasma collection, the outflow control valve 25a is closed (at this time, the liquid control valve 5a is closed while the outflow control valve 4a is opened), and the filtrate in the intermediate circuit 30 is guided to the return fluid circuit 4 via a bypass circuit 70 described later. The outflow control valves 25a and 4a function as the first control valves in the present invention and constitute a flow path changing section in the present invention.

[0029] The intermediate circuit 30 is a circuit connecting the first blood purifier 10 and the second blood purifier 20. A pump 40 for transporting the filtrate from the first blood purifier 10 toward the second blood purifier 20 is provided in the intermediate circuit 30. Further, a pressure measuring unit 7 for measuring the in-line pressure between the pump 40 and the second blood purifier 20 is provided in the intermediate circuit 30. The value of the in-line pressure measured by the pressure measuring unit 7 is used for controlling a flow path changing section (the outflow control valve 25a, the bypass control valve 71a, etc.). Incidentally, a warmer 8 for warming the filtrate is provided in the intermediate circuit 30. The warmer 7 may be provided in the return fluid circuit 4.

[0030] In addition, in the present embodiment, a bypass line 72 is provided that connects a position between the warmer 8 and the filtrate inflow port 21 of the second blood purifier 20 in the intermediate circuit 30 (a position upstream of the filtrate inflow port 21 of the second blood purifier 20) and the bag connection line 5. As an example, the bypass line 72 can connect a position upstream of the filtrate inflow port 21 of the second blood purifier 20 and a position downstream of the liquid pump 6 in the bag connection line 5. The bypass line 72 functions as a bypass flow path when the second blood purifier 20 becomes clogged, and is provided with a bypass control valve 72a controlled by the control unit 80.

[0031] When the second blood purifier 20 is not clogged, the bypass control valve 72a is closed, and the intermediate circuit 30 and the bag connection line 5 do not communicate with each other. On the other hand, when the second blood purifier 20 becomes clogged, the bypass control valve 72a is opened, and a bypass circuit 70 that connects the intermediate circuit 30 and the return liquid circuit 4 is formed by a part of the bag connection line 5 (the part connecting the bypass line 72 and the return liquid circuit 4) and the bypass line 72. Similarly, the bypass control valve 71a provided in the bag connection line 5 and controlled by the control unit 80 is also closed when the second blood purifier 20 is not clogged, and is opened when the second blood purifier 20 becomes clogged. The bypass control valves 71a and 72a function as the second control valve in the present invention and constitute a flow path changing unit in the present invention.

[0032] By providing the bypass line 72 in this way, the following secondary effects can be obtained.

[0033] That is, in a conventional blood purification apparatus having two blood purifiers, while performing a "priming process" of flowing and filling a priming liquid from the second blood purifier to the first blood purifier, a bag containing physiological saline is connected to the blood outlet section 3a (or the blood inlet section 2a), and a "washing process" of flowing a prescribed amount of physiological saline from the first blood purifier to the second blood purifier for washing is performed. However, in order to prevent the air accumulated inside the first blood purifier from flowing into the second blood purifier at the start of the operation of the washing process, a chamber was provided on the upstream side of the second blood purifier to remove the air. However, providing such a chamber has a problem that, in addition to an increase in the price and volume of the apparatus, the circuit configuration becomes complicated.

[0034] In contrast, in the present embodiment, regarding the cleaning of the first blood purifier 10, the physiological saline flows in the order of the blood return circuit 3 (or the blood collection circuit 2), the first blood purifier 10, the intermediate circuit 30, the bypass line 72, and the bag connection line 5 and is sent to the container 90. That is, when the first blood purifier 10 is cleaned, since the physiological saline does not pass through the second blood purifier 20, it is possible to avoid the air accumulated inside the first blood purifier 10 from flowing into the second blood purifier 20. Note that when the first blood purifier 10 is cleaned, the bypass control valve 72a is opened, and the liquid control valve 5a and the bypass control valve 71a are closed. Regarding the cleaning of the second blood purifier 20 performed after the cleaning of the first blood purifier 10, the physiological saline flows in the order of the blood return circuit 3 (or the blood collection circuit 2), the first blood purifier 10, the intermediate circuit 30, the second blood purifier 20, the return liquid circuit 4, and the bag connection line 5 and is sent to the container 90. Note that when the second blood purifier 20 is cleaned, the bypass control valve 72a and the liquid control valve 5a are closed, and the bypass control valve 71a is opened. Since the "cleaning step" is implemented as described above, the chamber becomes unnecessary, and it is possible to reduce the cost and size of the apparatus and to simplify the circuit configuration. Further, since it is possible to clean the first blood purifier 10 alone, it is possible to clean the second blood purifier 20 via the first blood purifier 10 that has been cleaned and made clean in the cleaning of the second blood purifier 20.

[0035] The control unit 80 integrally controls each component of the blood purification apparatus 1. In particular, when the membrane pressure of the second blood purifier 20 exceeds a predetermined threshold value, the control unit 80 operates the air supply unit 60 to supply air to the air supply path 50, operates the pump 40, and closes the outflow control valves 25a and 4a while opening the bypass control valves 71a and 72a, thereby causing the filtrate to flow through the intermediate circuit 30 and the bypass circuit 70 and implementing "bypass recovery control" to recover the plasma through the return liquid circuit 4. The control unit 80 in the present embodiment is configured to implement "bypass recovery control" by estimating that the membrane pressure of the second blood purifier 20 exceeds a predetermined threshold value when the in-line pressure measured by the pressure measurement unit 7 exceeds a predetermined threshold value.

[0036] Next, with reference to FIG. 2, a control method of the blood purification device 1 (a plasma recovery method by the blood purification device 1) according to the present embodiment will be described.

[0037] First, the control unit 80 of the blood purification device 1 measures the value of the in-line pressure by the pressure measurement unit 7 provided in the intermediate circuit 30, and determines whether this value exceeds a predetermined threshold (pressure determination step). When the value of the in-line pressure is equal to or lower than the predetermined threshold, the control unit 80 estimates that the membrane pressure of the second blood purifier 20 is equal to or lower than the predetermined threshold (no clogging has occurred), and performs plasma recovery through the path indicated by the solid line in FIG. 2 (normal recovery control step). That is, the control unit 80 operates the air supply unit 60 to supply air to the air supply path 50, operates the pump 40, opens the outflow control valve 4a, closes the outflow control valve 25a, and closes the bypass control valves 71a and 72a, so that the filtrate is circulated through the intermediate circuit 30 and the second blood purifier 20 and recovered through the return liquid circuit 4.

[0038] On the other hand, when the value of the in-line pressure exceeds the predetermined threshold, the control unit 80 estimates that the membrane pressure of the second blood purifier 20 exceeds the predetermined threshold (clogging has occurred), and performs plasma recovery through the path indicated by the dashed-dotted line in FIG. 2 (bypass recovery control step). That is, the control unit 80 operates the air supply unit 60 to supply air to the air supply path 50, operates the pump 40, opens the outflow control valve 4a, closes the outflow control valve 25a, and opens the bypass control valves 71a and 72a, so that the filtrate is circulated through the intermediate circuit 30 and the bypass circuit 70 and recovered through the return liquid circuit 4.

[0039] In the blood purification device 1 according to the embodiment described above, a pump 40 provided in an intermediate circuit 30 that connects a first blood purifier 10 and a second blood purifier 20 and conveys the filtrate, an air supply unit 60 provided in an air supply path 50 connected to a port to which the intermediate circuit 30 of the first blood purifier 10 is not connected, a bypass circuit 70 that bypasses the second blood purifier 20, and a flow path changing unit (outflow control valve 25a and bypass control valves 71a, 72a) that changes the flow path of the filtrate are provided. When clogging occurs in the second blood purifier 20, the control unit 80 operates the air supply unit 60 to supply air to the air supply path 50, operates the pump 40, and controls the flow path changing unit, so that the filtrate can be circulated and recovered via the intermediate circuit 30 and the bypass circuit 70. Therefore, when recovering the filtrate existing in the region upstream of the second blood purifier 20, there is no need to attach a dummy tube or perform a hemostat operation, so the work burden on the user can be reduced. In addition, since the flow path connected to the existing filtration pressure port can be used as the air supply path 60, there is no need to newly add a flow path for air supply, and the configuration of the device is simplified.

[0040] Also, in the blood purification device 1 according to the embodiment described above, the control unit 80 controls the flow path changing unit (the outflow control valve 25a provided in the flow path connected to the outlet of the second blood purifier 20, and the bypass control valves 71a, 72a provided on the bypass circuit 71 and the bypass line 72), whereby the flow path change can be realized. That is, by opening the outflow control valve 25a (the first control valve) while closing the bypass control valves 71a, 72a (the second control valves) by the control unit 80, the filtrate can flow into the second blood purifier 20. On the other hand, by opening the bypass control valves 71a, 72a (the second control valves) while closing the outflow control valve 25a (the first control valve) by the control unit 80, the filtrate can flow into the bypass circuit 70.

[0041] Also, the control unit 80 of the blood purification device 1 according to the embodiment described above can control the flow path changing unit (outflow control valves 25a, 4a and bypass control valves 71a, 72a) based on the value of the in-line pressure measured by the pressure measurement unit 7 (the value of the in-line pressure between the pump 40 and the second blood purifier 20 in the intermediate circuit 30 connecting the first blood purifier 10 and the second blood purifier 20). That is, when the value of the in-line pressure measured by the pressure measurement unit 7 is less than a predetermined threshold value, the control unit 80 determines that the second blood purifier 20 is not clogged, and controls the flow path changing unit so that the filtrate flows into the second blood purifier 20. On the other hand, when the value of the in-line pressure measured by the pressure measurement unit 7 exceeds the predetermined threshold value, the control unit 80 determines that the second blood purifier 20 is clogged, and can control the flow path changing unit so that the filtrate flows into the bypass circuit 70.

[0042] Also, in the blood purification device 1 according to the embodiment described above, during the cleaning of the first blood purifier 10, since the physiological saline does not pass through the second blood purifier 20, it is possible to avoid the air accumulated inside the first blood purifier 10 from flowing into the second blood purifier 20.

[0043] <Second Embodiment> Next, the blood purification device 1A according to the second embodiment of the present invention will be described.

[0044] The blood purification device 1A according to the present embodiment is used for so-called plasma adsorption therapy (PA), and its configuration is slightly different from that of the blood purification device 1 in the first embodiment. That is, in the blood purification device 1 in the first embodiment used for double-filtration plasmapheresis (DFPP), a "plasma component separator" that further filters the filtrate supplied from the first blood purifier 10 to generate a return fluid is adopted as the second blood purifier 20. However, in the blood purification device 1A of the present embodiment, a "plasma adsorber" that adsorbs pathogenic substances in the plasma contained in the filtrate supplied from the first blood purifier 10 with an adsorbent to generate a return fluid is adopted as the second blood purifier 20A, and accordingly, the configuration of the bypass circuit is changed. On the other hand, other configurations of the blood purification device 1A according to the present embodiment are common to the corresponding configurations of the blood purification device 1 in the first embodiment. Therefore, in the present embodiment, the description will be centered on the configurations different from those in the first embodiment, and the detailed description of the configurations common to the first embodiment will be omitted and the same reference numerals as those in the first embodiment will be given.

[0045] As shown in FIG. 3, the blood purification device 1A according to the present embodiment includes a blood collection circuit 2, a blood return circuit 3, a first blood purifier 10, a second blood purifier 20A, an intermediate circuit 30, a pump 40, a control unit 80, etc. By driving the pump 40 in the forward direction by the control unit 80, the blood collected through the blood collection circuit 2 is configured to pass through the first blood purifier 10 and the second blood purifier 20A and be returned through the blood return circuit 3.

[0046] In addition, as shown in FIG. 3, the blood purification device 1A according to the present embodiment includes a pressure measurement unit 7, a warmer 8, an air supply unit 60 capable of supplying air to an air supply location 51 in an air supply passage 50 connected to a first blood purifier 10, a bypass circuit 70A that bypasses a second blood purifier 20, a flow path changing unit (outflow control valve 4a and bypass control valve 70Aa) that changes the flow path of the filtrate so that the filtrate flows into either the second blood purifier 20 or the bypass circuit 70A, and a waste line 9 for discarding the liquid that has flowed from the intermediate circuit 30 into the return liquid circuit 4 via the bypass circuit 70A. By operating the air supply unit 60 by the control unit 80 to supply air to the air supply passage 50, operating the pump 40, and controlling the flow path changing unit, control is implemented to circulate the filtrate through the intermediate circuit 30 and the bypass circuit 70A, so that plasma recovery can be performed.

[0047] The configurations of the blood collection circuit 2, the blood return circuit 3, the pressure measurement unit 7, the warmer 8, the first blood purifier 10, the intermediate circuit 30, the pump 40, the air supply passage 50, the air supply unit 60, and the control unit 80 are substantially the same as those in the first embodiment, and thus detailed descriptions thereof are omitted.

[0048] In the present embodiment, a waste line 9 for discarding the liquid that has flowed from the intermediate circuit 30 into the return liquid circuit 4 via the bag connection line 5 and the bypass circuit 70A is employed. The waste line 9 is connected to a position on the return liquid circuit 4 that is downstream of the bypass circuit 70A and upstream of the blood cell outflow port 12 of the first blood purifier 10. The waste line 9 is provided with a waste control valve 9a controlled by the control unit 80. When performing normal blood collection control, the control unit 80 closes the waste control valve 9a. On the other hand, for example, during a cleaning process, the control unit 80 opens the waste control valve 9a, and the liquid (liquid containing a filter filling liquid and unnecessary components) used for cleaning the first blood purifier 10 can be discarded via the bypass circuit 70A and the waste line 9 without passing through the second blood purifier 20.

[0049] The second blood purifier 20A in the present embodiment functions to adsorb specific substances (such as etiological substances) in the plasma contained in the filtrate supplied from the first blood purifier 10 via the intermediate circuit 30 with an adsorbent to generate a return fluid. In the present embodiment, a plasma adsorber in which the adsorbent is built into a cylindrical housing is adopted as the second blood purifier 20A. As shown in FIG. 3, the second blood purifier 20A has a filtrate inflow port 21A for allowing the filtrate to flow in and a plasma outflow port 22A for allowing the plasma from which specific substances have been removed after passing through the adsorbent to flow out. As shown in FIG. 3, the return fluid flowing out from the plasma outflow port 22A is conveyed to the blood return circuit 3 via the return fluid circuit 4, mixed with the blood cell components flowing out from the blood cell outflow port 12 of the first blood purifier 10, and then returned to the patient P via the blood lead-out portion 3a.

[0050] In the present embodiment, as shown in FIG. 3, an outflow control valve 4a controlled by the control unit 80 is provided in the return fluid circuit 4 connected to the plasma outflow port 22A. When there is no clogging in the second blood purifier 20A, the outflow control valve 4a is opened to allow the plasma to flow out from the plasma outflow port 22A. On the other hand, when clogging occurs in the second blood purifier 20A, the outflow control valve 4a is closed, and the filtrate in the intermediate circuit 30 is guided to the return fluid circuit 4 via a bypass circuit 70A described later. The outflow control valve 4a functions as the first control valve in the present invention and constitutes the flow path changing portion in the present invention.

[0051] The bypass circuit 70A in this embodiment is provided to connect a position between the warmer 8 and the filtrate inflow port 21A of the second blood purifier 20A in the intermediate circuit 30 (a position upstream of the filtrate inflow port 21A of the second blood purifier 20A) and a position downstream of the outflow control valve 4a in the return liquid circuit 4. The bypass circuit 70A functions as a bypass flow path when clogging occurs in the second blood purifier 20, and is provided with a bypass control valve 70Aa controlled by the control unit 80. When there is no clogging in the second blood purifier 20A, the bypass control valve 70Aa is closed, and the intermediate circuit 30 and the return liquid circuit 4 do not communicate with each other. On the other hand, when clogging occurs in the second blood purifier 20A, the bypass control valve 70Aa is opened, and the bypass circuit 70A is opened. The bypass control valve 70Aa functions as the second control valve in the present invention and constitutes a flow path changing unit in the present invention.

[0052] Next, with reference to FIG. 4, a control method of the blood purification apparatus 1A according to this embodiment (a plasma recovery method by the blood purification apparatus 1A) will be described.

[0053] The control unit 80 of the blood purification apparatus 1 first measures the value of the in-line pressure by the pressure measurement unit 7 provided in the intermediate circuit 30, and determines whether this value exceeds a predetermined threshold (pressure determination step). Then, when the value of the in-line pressure is equal to or lower than the predetermined threshold, the control unit 80 estimates that the membrane pressure of the second blood purifier 20A is equal to or lower than the predetermined threshold (no clogging has occurred), and performs plasma recovery along the path indicated by the solid line in FIG. 4 (normal recovery control step). That is, the control unit 80 operates the air supply unit 60 to supply air to the air supply path 50, operates the pump 40, and closes the bypass control valve 70Aa while opening the outflow control valve 4a, so that the filtrate is circulated through the intermediate circuit 30 and the second blood purifier 20A and recovered through the return liquid circuit 4.

[0054] On the one hand, when the value of the in-line pressure exceeds a predetermined threshold, the control unit 80 estimates that the membrane pressure of the second blood purifier 20A exceeds a predetermined threshold (clogging has occurred), and performs plasma recovery through the path indicated by the dashed line in FIG. 4 (bypass recovery control step). That is, the control unit 80 operates the air supply unit 60 to supply air to the air supply path 50, operates the pump 40, and opens the bypass control valve 70Aa while closing the outflow control valve 4a, so that the filtrate is circulated through the intermediate circuit 30 and the bypass circuit 70A and recovered through the return liquid circuit 4.

[0055] In the blood purification device 1A according to the embodiment described above, a pump 40 provided in the intermediate circuit 30 connecting the first blood purifier 10 and the second blood purifier 20A for transporting the filtrate, an air supply unit 60 provided in the air supply path 50 connected to the port to which the intermediate circuit 30 of the first blood purifier 10 is not connected, a bypass circuit 70A bypassing the second blood purifier 20A, and a flow path changing unit (outflow control valve 4a and bypass control valve 70Aa) for changing the flow path of the filtrate. When clogging occurs in the second blood purifier 20A, the control unit 80 operates the air supply unit 60 to supply air to the air supply path 50, operates the pump 40, and controls the flow path changing unit, so that the filtrate can be circulated through the intermediate circuit 30 and the bypass circuit 70A and recovered. Therefore, when recovering the filtrate existing in the region upstream of the second blood purifier 20A, there is no need to attach a dummy tube or perform a hemostat operation, so the work burden on the user can be reduced. In addition, since the flow path connected to the existing filtration pressure port can be used as the air supply path 60, there is no need to newly add a flow path for air supply, and the configuration of the device is simplified.

[0056] In the blood purification device 1A according to the embodiment described above, by controlling various control valves (the outflow control valve 4a provided in the flow path connected to the outlet of the second blood purifier 20A and the bypass control valve 70Aa provided on the bypass circuit 70A) with the control unit 80, a flow path change can be realized. That is, by opening the outflow control valve 4a (the first control valve) and closing the bypass control valve 70Aa (the second control valve) with the control unit 80, the filtrate can be made to flow into the second blood purifier 20A. On the other hand, by opening the bypass control valve 70Aa (the second control valve) and closing the outflow control valve 4a (the first control valve) with the control unit 80, the filtrate can be made to flow into the bypass circuit 70A.

[0057] Also, the control unit 80 of the blood purification device 1A according to the embodiment described above can control the flow path changing unit (the outflow control valve 4a and the bypass control valve 70Aa) based on the value of the in-line pressure measured by the pressure measurement unit 7 (the value of the in-line pressure between the pump 40 and the second blood purifier 20A in the intermediate circuit 30 connecting the first blood purifier 10 and the second blood purifier 20A). That is, when the value of the in-line pressure measured by the pressure measurement unit 7 is less than a predetermined threshold value, the control unit 80 determines that the second blood purifier 20A is not clogged, and controls the flow path changing unit so that the filtrate flows into the second blood purifier 20A. On the other hand, when the value of the in-line pressure measured by the pressure measurement unit 7 exceeds the predetermined threshold value, the control unit 80 determines that the second blood purifier 20A is clogged, and can control the flow path changing unit so that the filtrate flows into the bypass circuit 70A.

[0058] Also, in the blood purification device 1A according to the embodiment described above, since it is provided with a waste line 9 for discarding the liquid that has flowed into the bypass circuit 70A, the liquid (liquid containing the filter filling liquid and unnecessary components) used for cleaning the first blood purifier 10 can be discarded via the bypass circuit 70A and the waste line 9 without passing through the second blood purifier 20A. Note that when discarding the liquid via the waste line 9, the control unit 80 closes the control valve 4b (see FIGS. 3 and 4) provided in the return liquid circuit 4.

[0059] The present invention is not limited to each of the above embodiments. Even if those skilled in the art make appropriate design changes to these embodiments, as long as they have the features of the present invention, they are included in the scope of the present invention. That is, each element included in each of the above embodiments and its arrangement, material, conditions, shape, size, etc. are not limited to those illustrated and can be changed as appropriate. In addition, each element included in each of the above embodiments can be combined as long as it is technically possible, and as long as the combination includes the features of the present invention, it is included in the scope of the present invention.

Explanation of Reference Numerals

[0060] 1·1A…Blood purification device 4a…Outflow control valve (first control valve, flow path changing section) 7…Pressure measurement section 9…Waste line 10…First blood purifier 20·20A…Second blood purifier 25a…Outflow control valve (first control valve, flow path changing section) 30…Intermediate circuit 40…Pump 50…Air supply line 51…Air supply location 60…Air supply section 70·70A…Bypass circuit 70Aa·71a·72a…Bypass control valve (second control valve, flow path changing section) 80…Control section

Claims

1. A first blood purifier that generates a filtrate containing plasma by filtering blood; A second blood purifier that further filters the filtrate supplied from the first blood purifier or adsorbs the plasma contained in the filtrate to generate a return fluid; A pump provided in an intermediate circuit connecting the first blood purifier and the second blood purifier for transporting the filtrate from the first blood purifier toward the second blood purifier; An air supply passage connected to a port of the first blood purifier to which the intermediate circuit is not connected; An air supply unit provided in the air supply passage; A bypass circuit that bypasses the second blood purifier; A flow path changing unit that changes the flow path of the filtrate so that the filtrate flows into either the second blood purifier or the bypass circuit; A control unit that controls the air supply unit to supply air to the air supply passage, operates the pump, and controls the flow path changing unit to circulate the filtrate through the intermediate circuit and the bypass circuit; A blood purification device comprising the above.

2. The flow path changing unit includes a first control valve provided in a flow path connected to the outlet of the second blood purifier and a second control valve provided on the bypass circuit; The control unit controls the first control valve and the second control valve. The blood purification device according to Claim 1.

3. When the membrane pressure of the second blood purifier exceeds a predetermined threshold value, the control unit operates the air supply unit to supply air to the air supply passage, operates the pump, and opens the second control valve while closing the first control valve to circulate the filtrate through the intermediate circuit and the bypass circuit. The blood purification device according to Claim 2.

4. Further comprising a pressure measurement unit that measures the in-line pressure of the intermediate circuit between the pump and the second blood purifier; The control unit controls the flow path changing unit based on the value of the in-line pressure measured by the pressure measurement unit. The blood purification device according to any one of Claims 1 to 3.

5. When the value of the in-line pressure measured by the pressure measurement unit exceeds a predetermined threshold value, the control unit operates the air supply unit to supply air to the air supply passage, operates the pump, and controls the flow path changing unit to implement control for causing the filtrate to flow through the intermediate circuit and the bypass circuit. The blood purification device according to claim 4.

6. The blood purification device according to claim 1, further comprising a waste line for discarding the liquid that has flowed into the bypass circuit.

7. A first blood purifier that generates a filtrate containing plasma by filtering blood, a second blood purifier that further filters the filtrate supplied from the first blood purifier or adsorbs the plasma contained in the filtrate to generate a return liquid, a pump provided in an intermediate circuit connecting the first blood purifier and the second blood purifier for transporting the filtrate from the first blood purifier toward the second blood purifier, an air supply passage connected to a port of the first blood purifier to which the intermediate circuit is not connected, an air supply unit provided in the air supply passage, a bypass circuit that bypasses the second blood purifier, a flow path changing unit that changes the flow path of the filtrate so that the filtrate flows into either the second blood purifier or the bypass circuit, and a control unit. A control method for a blood purification device, comprising: A control step of operating the air supply unit by the control unit to supply air to the air supply passage, operating the pump, and controlling the flow path changing unit to cause the filtrate to flow through the intermediate circuit and the bypass circuit. A control method for a blood purification device.

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