Blood purification device and control method thereof

Abstract

To provide a blood purification device with a first blood purifier and a second blood purifier, shortening a total time required for recovering plasma even when the second blood purifier is clogged.SOLUTION: A blood purification device 1 includes: a pump 40 provided in an intermediate circuit 30 connecting a first blood purifier 10 and a second blood purifier 20 and transporting a filtrate; an air supply unit 50 for supplying air to the air supply point 31 of the intermediate circuit 30; and a control unit 80. The control unit 80 controls the pump 40 and the air supply unit 50 to simultaneously perform downstream recovery control and upstream recovery control: the downstream recovery control in which air is supplied to the air supply point 31, thereby sending the filtrate in the downstream side of the intermediate circuit 30 through the second blood purifier 20 to a blood return circuit 3 and recovering it; and the upstream recovery control in which air is supplied to the air supply point 31 while driving the pump 40 in a reverse direction, thereby sending the filtrate in the upstream side of the intermediate circuit 30 through the first blood purifier 10 to the blood return circuit 3 and recovering it.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Conventionally, blood purification treatments have been performed in which blood is taken from a patient's body, disease-causing substances and specific white blood cells are removed from the blood, and the blood is returned to the body. In such blood purification treatments, blood purification devices are used that include a blood circuit for circulating the blood taken from the body and returning it to the body, and a blood purifier having processing materials such as adsorbents and separators for removing and separating specific substances.

[0003] In recent years, blood purification devices equipped with multiple blood purifiers have been proposed. For example, a blood purification device has been proposed that includes a first blood purifier that produces a filtrate containing plasma by filtering blood, a second blood purifier that further filters the filtrate supplied from the first blood purifier to separate it into low-molecular-weight plasma components and high-molecular-weight plasma components, and an intermediate circuit that connects the first blood purifier and the second blood purifier, and that is configured to collect plasma remaining in the intermediate circuit by supplying air (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-139791 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a conventional blood purification device such as that described in Patent Document 1 is adopted, in the event of clogging of the second blood purifier, it is necessary to reduce the air supply rate to avoid an increase in membrane pressure resulting in residual plasma. As a result, it takes a relatively long time to complete the downstream plasma recovery process (a process in which the filtrate present in the downstream region of the intermediate circuit is sent to the blood return circuit via the second blood purifier and recovered), which results in a problem that the total time required for plasma recovery is long.

[0006] The present invention has been made in consideration of the above circumstances, and has an object to shorten the total time required for plasma recovery in a blood purification device comprising a first blood purifier and a second blood purifier, even when clogging occurs in the second blood purifier. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, a first blood purification apparatus according to the present invention comprises a first blood purifier which produces a filtrate containing plasma by filtering blood, a second blood purifier which further filters the filtrate supplied from the first blood purifier or adsorbs plasma contained in the filtrate to produce a return liquid, a pump which is provided in an intermediate circuit connecting the first blood purifier and the second blood purifier and transports the filtrate from the first blood purifier to the second blood purifier, an air supply unit which is capable of supplying air to an air supply point which is located downstream of the pump in the intermediate circuit, and a control unit which controls the pump and the air supply unit, and which purifies blood collected via a blood collection circuit by driving the pump in a forward direction using the control unit. This is a blood purification device in which blood is returned via a blood return circuit via a first blood purifier and a second blood purifier, and the control unit controls the pump and the air supply unit to perform both of the following overlapping control for at least a predetermined time: downstream recovery control, in which the air supply unit supplies air to the air supply point, so that filtrate present in the area downstream of the air supply point in the intermediate circuit is sent to the blood return circuit via the second blood purifier and recovered, and upstream recovery control, in which the air supply unit supplies air to the air supply point while driving the pump in the reverse direction, so that filtrate present in the area upstream of the air supply point in the intermediate circuit is sent to the blood return circuit via the first blood purifier and recovered.

[0008] A first control method according to the present invention comprises a first blood purifier which produces a filtrate containing plasma by filtering blood, a second blood purifier which further filters the filtrate supplied from the first blood purifier or adsorbs plasma contained in the filtrate to produce a return liquid, a pump which is provided in an intermediate circuit connecting the first blood purifier and the second blood purifier and transports the filtrate from the first blood purifier to the second blood purifier, an air supply unit which is capable of supplying air to an air supply point located downstream of the pump in the intermediate circuit, and a control unit, and by driving the pump in a forward direction with the control unit, blood collected via a blood collection circuit is passed through the first blood purifier and the second blood purifier to be returned to the blood return circuit. a downstream recovery control step in which the control unit controls the air supply unit so that air is supplied to the air supply point by the air supply unit, thereby sending filtrate present in a region downstream of the air supply point in the intermediate circuit via the second blood purifier to the blood return circuit and recovering it; and an upstream recovery control step in which the control unit controls the air supply unit and the pump so that filtrate present in a region upstream of the air supply point in the intermediate circuit is sent to the blood return circuit via the first blood purifier and recovered by driving the pump in the reverse direction while supplying air to the air supply point by the air supply unit, thereby overlapping both steps for at least a predetermined time.

[0009] By adopting such a configuration and method, both downstream collection control for collecting plasma contained in the filtrate present in the downstream region of the intermediate circuit and upstream collection control for collecting plasma contained in the filtrate present in the upstream region of the intermediate circuit can be performed with at least a predetermined time overlap. For example, even in a case where downstream collection control takes a relatively long time due to clogging of the second blood purifier, both downstream collection control and upstream collection control can be performed with at least a predetermined time overlap (for example, upstream collection control can be started before downstream collection control is completed, or downstream collection control and upstream collection control can be started simultaneously). Therefore, it is not necessary to wait for the start of upstream collection control until downstream collection control is completed, so the total time required for plasma collection can be shortened.

[0010] In the first blood purification apparatus according to the present invention, the control unit can control the pump and the gas supply unit so as to simultaneously perform the downstream recovery control and the upstream recovery control, and in this case, the control unit can set the flow rate of the pump to be smaller than the flow rate of the gas supply unit.

[0011] A second blood purification apparatus according to the present invention comprises a first blood purifier which produces a filtrate containing plasma by filtering blood, a second blood purifier which further filters the filtrate supplied from the first blood purifier or adsorbs plasma contained in the filtrate to produce a return liquid, a pump which is provided in an intermediate circuit connecting the first blood purifier and the second blood purifier and transports the filtrate from the first blood purifier to the second blood purifier, a first air supply unit capable of supplying air to a first air supply point which is located downstream of the pump in the intermediate circuit, an air supply path connected to a port of the first blood purifier to which the intermediate circuit is not connected, a second air supply unit which is provided at a second air supply point which is located in the air supply path, and a control unit which controls the pump, the first air supply unit, and the second air supply unit, and by driving the pump in the forward direction with the control unit, blood collected via a blood collection circuit is supplied to the first blood purifier and the second blood purifier. a control unit that controls the pump, the first air supply unit, and the second air supply unit to perform downstream recovery control in which the first air supply unit supplies air to the first air supply point, thereby sending filtrate present in a region downstream of the first air supply point in the intermediate circuit to the blood return circuit via the second blood purifier and recovering it; a first upstream recovery control in which the first air supply unit supplies air to the first air supply point while driving the pump in the reverse direction, thereby sending filtrate present in a region upstream of the first air supply point in the intermediate circuit to the blood return circuit via the first blood purifier and recovering it; and a second upstream recovery control in which the second air supply unit supplies air to the second air supply point, thereby sending filtrate present outside the filtration membrane in the first blood purifier to the blood return circuit and recovering it.

[0012] A second control method according to the present invention relates to a blood purification system comprising: a first blood purifier which produces a filtrate containing plasma by filtering blood; a second blood purifier which further filters the filtrate supplied from the first blood purifier or adsorbs plasma contained in the filtrate to produce a return liquid; a pump which is provided in an intermediate circuit connecting the first blood purifier and the second blood purifier and transports the filtrate from the first blood purifier to the second blood purifier; a first air supply unit capable of supplying air to a first air supply point located downstream of the pump in the intermediate circuit; an air supply path connected to a port of the first blood purifier to which the intermediate circuit is not connected; a second air supply unit provided at a second air supply point located in the air supply path; and a control unit, wherein the control unit drives the pump in the forward direction to return blood collected via a blood collection circuit through the first blood purifier and the second blood purifier via a blood return circuit. The control method for the device includes a downstream recovery control step in which the control unit controls the first air supply unit so that the first air supply unit supplies air to the first air supply point, thereby sending filtrate present in a region downstream of the first air supply point in the intermediate circuit via the second blood purifier to the blood return circuit for recovery; a first upstream recovery control step in which the control unit controls the first air supply unit and the pump by driving the pump in the reverse direction while supplying air to the first air supply point by the first air supply unit, thereby sending filtrate present in a region upstream of the first air supply point in the intermediate circuit via the first blood purifier to the blood return circuit for recovery; and a second upstream recovery control step in which the control unit controls the second air supply unit by supplying air to the second air supply point, thereby sending filtrate present outside the filtration membrane in the first blood purifier to the blood return circuit for recovery.

[0013] By adopting such a configuration and method, it is possible to carry out downstream collection control for collecting plasma contained in the filtrate present in the downstream region of the intermediate circuit, first upstream collection control for collecting plasma contained in the filtrate present in the upstream region of the intermediate circuit, and second upstream collection control for collecting plasma contained in the filtrate present outside the filtration membrane in the first blood purifier. Therefore, when clogging occurs in the second blood purifier and a relatively long time is required for downstream collection control, the one that requires a relatively long time out of the first upstream collection control and the second upstream collection control (for example, when the capacity of the filtration membrane of the first blood purifier is relatively large, the second upstream collection control takes a relatively long time, and when the capacity of the filtration membrane is relatively small, the first upstream collection control takes a relatively long time) can be carried out simultaneously with the downstream collection control. This makes it possible to shorten the total time required for plasma collection.

[0014] In the second blood purification device of the present invention, the control unit can control the pump, the first air supply unit, and the second air supply unit so as to change the order in which the downstream recovery control, the first upstream recovery control, and the second upstream recovery control are performed in accordance with specified conditions.

[0015] By adopting such a configuration, the order of performing the downstream recovery control, the first upstream recovery control, and the second upstream recovery control can be changed according to a predetermined condition (e.g., the capacity and type of the filtration membrane of the first blood purifier.) Therefore, by setting various recovery patterns according to the condition, it is possible to contribute to further shortening the plasma recovery time.

[0016] In the second blood purification apparatus according to the present invention, the control unit can control the pump and the first gas supply unit so as to simultaneously perform the downstream collection control and the first upstream collection control, and at this time, can set the flow rate of the pump to be smaller than the flow rate of the first gas supply unit. The control unit can also control the pump, the first gas supply unit, and the second gas supply unit so as to perform the second upstream collection control before the downstream collection control and the first upstream collection control. Alternatively, the control unit can control the pump, the first gas supply unit, and the second gas supply unit so as to perform the second upstream collection control after the downstream collection control and the first upstream collection control.

[0017] In the second blood purification apparatus according to the present invention, the control unit can control the pump and the second gas supply unit to simultaneously perform the downstream collection control and the second upstream collection control, and can stop the pump at this time. The control unit can also control the pump, the first gas supply unit, and the second gas supply unit to perform the first upstream collection control before the downstream collection control and the second upstream collection control. Alternatively, the control unit can control the pump, the first gas supply unit, and the second gas supply unit to perform the first upstream collection control after the downstream collection control and the second upstream collection control.

[0018] In addition, in the second blood purification apparatus of the present invention, the control unit can control the pump, the first air supply unit, and the second air supply unit so as to simultaneously perform downstream recovery control, first upstream recovery control, and second upstream recovery control.

[0019] In addition, in the second blood purification device of the present invention, the control unit can control the pump, the first air supply unit, and the second air supply unit so that the total flow rate of plasma recovered when downstream recovery control, first upstream recovery control, and second upstream recovery control are performed is equal to or less than a predetermined threshold value.

[0020] By adopting such a configuration, the total flow rate of collected plasma can be kept below a predetermined threshold, thereby making it possible to suppress the adverse effects on the patient that would be caused by a sudden increase in the amount of returned blood. Effect of the Invention

[0021] According to the present invention, in a blood purification apparatus comprising a first blood purifier and a second blood purifier, it is possible to shorten the total time required for plasma recovery even if clogging occurs in the second blood purifier. [Brief description of the drawings]

[0022] [Figure 1] 1 is a configuration diagram for explaining the configuration of a blood purification device according to a first embodiment of the present invention. FIG. [Diagram 2] FIG. 2 is an explanatory diagram for explaining a control method (plasma recovery method) of the blood purification apparatus according to the first embodiment of the present invention. [Diagram 3] FIG. 4 is a configuration diagram for explaining the configuration of a blood purification device according to a second embodiment of the present invention. [Figure 4] FIG. 4 is an explanatory diagram for explaining a control method (plasma recovery method) of a blood purification apparatus according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0024] First Embodiment First, the configuration of a blood purification apparatus 1 according to a first embodiment of the present invention will be described. The blood purification apparatus 1 according to this embodiment is used for so-called double filtration plasma pheresis (DFPP).

[0025] As shown in FIG. 1, the blood purification device 1 of this embodiment comprises 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., and is configured such that by driving the pump 40 in the forward direction with the control unit 80, blood collected via the blood collection circuit 2 is passed through the first blood purifier 10 and the second blood purifier 20 and returned via the blood return circuit 3.

[0026] As shown in FIG. 1, the blood purification device 1 according to this embodiment includes a first air supply unit 50 capable of supplying air to an air supply point (first air supply point) 31 in the intermediate circuit 30, and a second air supply unit 70 capable of supplying air to an air supply point (second air supply point) 61 in an air supply passage 60 connected to the first blood purifier 10. The blood purification device 1 is configured to be able to collect plasma in a plurality of modes by controlling the pump 40, the first air supply unit 50, and the second air supply unit 70 with a control unit 80. The control of plasma collection will be described in detail later. The air supply unit can be realized by various known methods, such as by a pump that sends air into the circuit and a valve provided between the pump and the circuit, and detailed configurations are not shown in the drawings.

[0027] The first blood purifier 10 in this embodiment functions to generate a filtrate containing plasma by filtering the blood of the patient P introduced via the blood introduction part 2a and the blood collection circuit 2 by a blood collection pump (not shown). In this embodiment, a plasma separator having a filtration membrane for separating blood into blood cells and plasma built into a cylindrical housing is used as the first blood purifier 10. To promote this separation, a structure for increasing the internal pressure of the blood collection circuit 2 (such as a gas-liquid separator or an air valve) may be provided.

[0028] 1, the first blood purifier 10 has a blood inflow port 11 for introducing blood, a blood cell outflow port 12 for introducing blood cell components separated from blood plasma by a filtration membrane, a filtrate outflow port 13 for introducing blood plasma components (filtrate) separated from blood cells by the filtration membrane, and an air supply port 14 to which an air supply path 60 described below is connected. The blood inflow port 11 and the blood cell outflow port 12 are connected to 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 are connected to the space outside the filtration membrane of the first blood purifier 10.

[0029] The second blood purifier 20 in this embodiment functions to generate a return liquid by further filtering the filtrate supplied from the first blood purifier 10 via the intermediate circuit 30. In this embodiment, a plasma component separator having a cylindrical housing with a filtration membrane that separates the filtrate into low molecular weight plasma components and high molecular weight plasma components is used as the second blood purifier 20.

[0030] As shown in Fig. 1, the second blood purifier 20 has a filtrate inlet port 21 for introducing the filtrate, a discharge port 22 for discharging high molecular weight plasma components (including pathological substances, etc.) separated from low molecular weight plasma by the filtration membrane, a return fluid outlet port 23 for discharging low molecular weight plasma components (return fluid) separated from high molecular weight plasma components by the filtration membrane, and a replacement fluid supply port 24 to which replacement fluid stored in the container 90 is supplied. The filtrate inlet port 21 and the discharge port 22 are connected to the space inside the filtration membrane of the second blood purifier 20. On the other hand, the return fluid outlet port 23 and the replacement fluid supply port 24 are connected to the space outside the filtration membrane of the second blood purifier 20.

[0031] The high molecular weight plasma components discharged from the discharge port 22 can be discarded as they are, or can be returned to the intermediate circuit 30 via a circulation circuit (not shown) and mixed with the filtrate and then flowed back into the filtrate inlet port 21 of the second blood purifier 20 to be treated again by the filtration membrane. The return liquid (low molecular weight plasma components) flowing out from the return liquid outlet port 23 is transported to the blood return circuit 3 via the return liquid circuit 4 as shown in FIG. 1, mixed with the blood cell components flowing out from the blood cell outlet port 12 of the first blood purifier 10, and returned to the patient P via the blood outlet portion 3a. The replacement liquid supply circuit 5 connecting the replacement liquid supply port 24 and the container 90 is provided with a replacement liquid pump 6 and an opening / closing valve 5a, which are driven and controlled by the control unit 80, so that the replacement liquid stored in the container 90 is supplied to the replacement liquid supply port 24 at the required timing.

[0032] The intermediate circuit 30 is a circuit connecting the first blood purifier 10 and the second blood purifier 20. The intermediate circuit 30 is provided with a pump 40 that transports the filtrate from the first blood purifier 10 to the second blood purifier 20. A first air supply unit (pump, etc.) 50 is connected to an air supply point (first air supply point) 31 located downstream of the pump 40 in the intermediate circuit 30 via an air supply path 32 that can supply air. By controlling the drive of the first air supply unit 50 with the control unit 80, air can be supplied to the intermediate circuit 30 via the air supply path 32 and the air supply point 31, thereby realizing the "downstream recovery control" described later. By controlling the drive of the pump 40 and the first air supply unit 50 with the control unit 80, air can be supplied to the intermediate circuit 30 via the air supply path 32 and the air supply point 31, and the pump 40 can be driven in the reverse direction, thereby realizing the "first upstream recovery control" described later. The intermediate circuit 30 is provided with a heater 7 that heats the filtrate. Incidentally, the humidifier 7 may be provided in the return liquid circuit 4.

[0033] 1, an air supply passage 60 is connected to the air supply port 14 of the first blood purifier 10. A second air supply unit (e.g., a pump) 70 capable of supplying air is connected to an air supply point (second air supply point) 61 arranged in the air supply passage 60. By controlling the driving of the second air supply unit 70 with the control unit 80, air can be supplied to the space outside the filtration membrane of the first blood purifier 10 via the second air supply point 61, the air supply passage 60, and the air supply port 14, thereby realizing a "second upstream recovery control" described later.

[0034] The control unit 80 performs integrated control of each component of the blood purification apparatus 1. In particular, the control unit 80 controls the first air supply unit 50 to perform "downstream recovery control" in which the filtrate present in the region downstream of the first air supply unit 31 in the intermediate circuit 30 is sent to the blood return circuit 3 via the second blood purifier 20 and recovered by supplying air to the first air supply point 31 by the first air supply unit 50. At this time, air from the first air supply unit 50 is sent to the filtrate supply port 21 of the second blood purifier 20, so that the plasma present in the space inside the filtration membrane of the second blood purifier 20 flows out from the return liquid outflow port 23, is transported to the blood return circuit 3 via the return liquid circuit 4, and is returned to the patient P via the blood lead-out unit 3a.

[0035] In addition, the control unit 80 controls the pump 40 and the first air supply unit 50 to perform a "first upstream recovery control" in which the filtrate present in the area upstream of the first air supply point 31 in the intermediate circuit 30 is sent to the blood return circuit 3 via the first blood purifier 10 and recovered by driving the pump 40 in the reverse direction while supplying air to the first air supply point 31 via the first air supply unit 50.

[0036] Furthermore, the control unit 80 controls the second air supply unit 70 to perform a "second upstream recovery control" in which the filtrate present outside the filtration membrane in the first blood purifier 10 is sent to the blood return circuit 3 and recovered by supplying air to the second air supply point 61 via the second air supply unit 70.

[0037] That is, the control unit 80 controls the pump 40, the first gas supply unit 50, and the second gas supply unit 70 so as to carry out these three modes of plasma collection control at appropriate timing.

[0038] The control unit 80 may control the pump 40, the first air supply unit 50, and the second air supply unit 70 to change the order in which the "downstream recovery control", the "first upstream recovery control", and the "second upstream recovery control" are performed depending on predetermined conditions (e.g., the capacity and type of the filtration membrane of the first blood purifier 10).

[0039] For example, when the capacity of the filtration membrane of the first blood purifier 10 is relatively small, it is assumed that the time required for the "second upstream recovery control" will be relatively short and the time required for the "first upstream recovery control" will be relatively long. In such a case, the control unit 80 controls the pump 40 and the first air supply unit 50 so that the "first upstream recovery control" and the "downstream recovery control", which require a relatively long time, are performed simultaneously (overlapped for at least a predetermined time).

[0040] At this time, the control unit 80 sets the flow rate of the pump 40 to be smaller than the flow rate of the first gas supply unit 50 (for example, the flow rate of the pump 40 is set to 20 ml / min, while the flow rate of the first gas supply unit 50 is set to 50 ml / min). This makes it possible to realize parallel processing of the "first upstream recovery control" and the "downstream recovery control".

[0041] In such a case, the control unit 80 can control the pump 40, the first air supply unit 50, and the second air supply unit 70 so that the "second upstream recovery control" is performed "before" the "downstream recovery control" and the "first upstream recovery control", or can control the pump 40, the first air supply unit 50, and the second air supply unit 70 so that the "second upstream recovery control" is performed "after" the "downstream recovery control" and the "first upstream recovery control".

[0042] On the other hand, when the capacity of the filtration membrane of the first blood purifier 10 is relatively large, it is assumed that the time required for the "second upstream recovery control" will be relatively long and the time required for the "first upstream recovery control" will be relatively short. In such a case, the control unit 80 controls the first gas supply unit 50 and the second gas supply unit 70 so as to simultaneously perform (overlap at least a predetermined time) the "second upstream recovery control" and the "downstream recovery control", which require a relatively long time, while stopping the pump 40.

[0043] In such a case, the control unit 80 can control the pump 40, the first air supply unit 50, and the second air supply unit 70 so that the "first upstream recovery control" is performed "before" the "downstream recovery control" and the "second upstream recovery control", or can control the pump 40, the first air supply unit 50, and the second air supply unit 70 so that the "first upstream recovery control" is performed "after" the "downstream recovery control" and the "second upstream recovery control".

[0044] In addition, the control unit 80 can also control the pump 40, the first air supply unit 50, and the second air supply unit 70 so that the "downstream recovery control", the "first upstream recovery control", and the "second upstream recovery control" are all performed simultaneously (overlapping for at least a predetermined time).

[0045] In any mode of plasma collection control, the control unit 80 in this embodiment controls the pump 40, the first gas supply unit 50, and the second gas supply unit 70 so that the total flow rate of plasma collected when "downstream collection control", "first upstream collection control", and "second upstream collection control" are performed is equal to or less than a predetermined threshold. By performing such control, the total flow rate of plasma collected can be suppressed to be equal to or less than a predetermined threshold, thereby making it possible to suppress adverse effects on the patient P caused by a sudden increase in the amount of returned blood.

[0046] Next, a method for controlling the blood purification apparatus 1 according to this embodiment (a method for collecting plasma by the blood purification apparatus 1) will be described with reference to FIG.

[0047] <Case of small filtration membrane capacity> First, a plasma recovery method in the case where the capacity of the filtration membrane of the first blood purifier 10 of the blood purification apparatus 1 is relatively small (below a predetermined threshold) will be described. In such a case, it is assumed that the time required for the "second upstream recovery control" is relatively short, and the time required for the "first upstream recovery control" is relatively long. Therefore, the control unit 80 of the blood purification apparatus 1 controls the pump 40 and the first air supply unit 50 to simultaneously perform the "first upstream recovery control" which takes a relatively long time, and the "downstream recovery control" which is assumed to take a relatively long time due to clogging of the second blood purifier 20, etc. (first upstream recovery control process and downstream recovery control process). Both the "first upstream recovery control" and the "downstream recovery control" are performed by air supplied from a common air supply unit (first air supply unit 50), so that the start and end times of both controls are almost the same. In such a case, the control unit 80 may perform the "second upstream recovery control" "before" the "downstream recovery control" and the "first upstream recovery control", or may perform the "second upstream recovery control" "after" the "downstream recovery control" and the "first upstream recovery control".

[0048] <Large capacity filtration membrane> Next, a plasma recovery method will be described in the case where the capacity of the filtration membrane of the first blood purifier 10 of the blood purification apparatus 1 is relatively large (exceeding a predetermined threshold value). In such a case, it is assumed that the time required for the "second upstream recovery control" is relatively long, and the time required for the "first upstream recovery control" is relatively short. Therefore, the control unit 80 of the blood purification apparatus 1 controls the first air supply unit 50 and the second air supply unit 70 so as to simultaneously perform (overlap at least a predetermined time) the "second upstream recovery control" which takes a relatively long time, and the "downstream recovery control" which is assumed to take a relatively long time due to clogging of the second blood purifier 20, while stopping the pump 40 (second upstream recovery control process and downstream recovery control process). The "second upstream recovery control" and the "downstream recovery control" are performed by air supplied from separate air supply units (the first air supply unit 50 and the second air supply unit 70), so that the start and end of both controls can be made different from each other. In such a case, the control unit 80 may perform the "first upstream recovery control" "before" the "downstream recovery control" and the "second upstream recovery control", or may perform the "first upstream recovery control" "after" the "downstream recovery control" and the "second upstream recovery control".

[0049] In the above cases, the control unit 80 switches the plasma collection control depending on the "capacity" of the filtration membrane of the first blood purifier 10. However, the control unit 80 can automatically switch the plasma collection control depending on the "type" of the filtration membrane of the first blood purifier 10. For example, if the first blood purifier 10 is a type having a relatively coarse filtration membrane, it is assumed that the time required for the "second upstream collection control" will be relatively short and the time required for the "first upstream collection control" will be relatively long. Therefore, the control unit 80 of the blood purification device 1 can control the pump 40 and the first air supply unit 50 to simultaneously perform the "first upstream collection control" which takes a relatively long time and the "downstream collection control" which is assumed to take a relatively long time due to clogging of the second blood purifier 20, etc. On the other hand, if the first blood purifier 10 is a type having a relatively fine filtration membrane, it is assumed that the time required for the "second upstream collection control" will be relatively long and the time required for the "first upstream collection control" will be relatively short. Therefore, the control unit 80 of the blood purification device 1 controls the first air supply unit 50 and the second air supply unit 70 to simultaneously (overlap for at least a predetermined time) perform the ``second upstream recovery control,'' which takes a relatively long time, and the ``downstream recovery control,'' which is expected to take a relatively long time due to clogging of the second blood purifier 20, while stopping the pump 40.

[0050] The control unit 80 can also control the pump 40, the first air supply unit 50, and the second air supply unit 70 so as to simultaneously perform the "first upstream recovery control" and the "second upstream recovery control" (first upstream recovery control process and second upstream recovery control process). In such a case, the control unit 80 can perform the "downstream recovery control" "before" the "first upstream recovery control" and the "second upstream recovery control", or can perform the "downstream recovery control" "after" the "first upstream recovery control" and the "second upstream recovery control".

[0051] Depending on the capacity and type of the filtration membrane of the first blood purifier 10, it may be difficult to predict which of the "first upstream recovery control" and the "second upstream recovery control" will take longer. In such a case, the control unit 80 of the blood purification device 1 can control the pump 40, the first air supply unit 50, and the second air supply unit 70 so as to simultaneously carry out the "downstream recovery control", the "first upstream recovery control", and the "second upstream recovery control" (downstream recovery control step, first upstream recovery control step, second upstream recovery control step). In this way, the "downstream recovery control", which is expected to take a relatively long time due to clogging of the second blood purifier 20, can be carried out simultaneously with the "first upstream recovery control" and the "second upstream recovery control" (either of these is expected to take a long time), thereby shortening the total time required for plasma recovery.

[0052] In the blood purification device 1 according to the embodiment described above, it is possible to perform a "downstream recovery control" for recovering plasma contained in the filtrate present in the downstream region of the intermediate circuit 30, a "first upstream recovery control" for recovering plasma contained in the filtrate present in the upstream region of the intermediate circuit 30, and a "second upstream recovery control" for recovering plasma contained in the filtrate present outside the filtration membrane in the first blood purifier 10. Therefore, even in a case where the second blood purifier 20 is clogged and a relatively long time is required for the "downstream recovery control", the one that requires a relatively long time out of the "first upstream recovery control" and the "second upstream recovery control" (for example, when the capacity of the filtration membrane of the first blood purifier 10 is relatively large, the "second upstream recovery control" takes a relatively long time, and when the capacity of the filtration membrane is relatively small, the "first upstream recovery control" takes a relatively long time) can be performed simultaneously with the "downstream recovery control". This allows the total time required for plasma recovery to be shortened.

[0053] Furthermore, in the blood purification device 1 according to the embodiment described above, the order of performing the "downstream collection control", the "first upstream collection control", and the "second upstream collection control" can be changed depending on predetermined conditions (e.g., the capacity and type of the filtration membrane of the first blood purifier 10). Therefore, by setting various collection patterns depending on the conditions, it is possible to contribute to further shortening the plasma collection time.

[0054] In the blood purification apparatus 1 according to the embodiment described above, the control unit 80 can control the pump 40, the first gas supply unit 50, and the second gas supply unit 70 so that the total flow rate of plasma collected when the "downstream collection control", "first upstream collection control", and "second upstream collection control" are performed is equal to or less than a predetermined threshold. Therefore, the total flow rate of plasma collected can be suppressed to be equal to or less than a predetermined threshold, making it possible to suppress adverse effects on the patient P caused by a sudden increase in the amount of returned blood.

[0055] Second Embodiment Next, a blood purification apparatus 1A according to a second embodiment of the present invention will be described.

[0056] The blood purification apparatus 1 according to this embodiment is used for so-called plasma adsorption (PA) therapy, and its configuration is slightly different from that of the blood purification apparatus 1 of the first embodiment. That is, in the blood purification apparatus 1 of the first embodiment used for double membrane filtration plasma exchange therapy (DFPP), a "plasma component separator" that further filters the filtrate supplied from the first blood purifier 10 to generate a return liquid is adopted as the second blood purifier 20, whereas in the blood purification apparatus 1A of this embodiment, a "plasma adsorption apparatus" 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 liquid is adopted as the second blood purifier 20A. Meanwhile, the other configurations of the blood purification apparatus 1A according to this embodiment are common to the corresponding configurations of the blood purification apparatus 1 of the first embodiment. For this reason, in this embodiment, the configurations different from those of the first embodiment will be mainly described, and detailed descriptions of the configurations common to the first embodiment will be omitted and the same reference numerals as those of the first embodiment will be used.

[0057] As shown in FIG. 3, the blood purification device 1A of this 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., and is configured such that by driving the pump 40 in the forward direction with the control unit 80, blood collected via the blood collection circuit 2 is passed through the first blood purifier 10 and the second blood purifier 20A and returned via the blood return circuit 3.

[0058] Furthermore, as shown in FIG. 3, the blood purification apparatus 1A of this embodiment is equipped with a first air supply section 50 capable of supplying air to an air supply point (first air supply point) 31 in the intermediate circuit 30, and a second air supply section 70 capable of supplying air to an air supply point (second air supply point) 61 in an air supply passage 60 connected to the first blood purifier 10, and is configured to be able to perform plasma recovery in a variety of manners by controlling the pump 40, the first air supply section 50, and the second air supply section 70 with the control section 80.

[0059] The configurations of the blood collection circuit 2, blood return circuit 3, first blood purifier 10, intermediate circuit 30, pump 40, first air supply section 50, air supply path 60, second air supply section 70 and control section 80 are substantially the same as those in the first embodiment, so detailed explanations are omitted.

[0060] The second blood purifier 20A in this embodiment functions to adsorb specific substances (pathogens, etc.) in plasma contained in the filtrate supplied from the first blood purifier 10 via the intermediate circuit 30 with an adsorbent to generate a return liquid. In this embodiment, a plasma adsorber with an adsorbent built in a cylindrical housing is used as the second blood purifier 20A. As shown in FIG. 3, the second blood purifier 20A has a filtrate inflow port 21A for introducing the filtrate and a plasma outflow port 22A for discharging the plasma from which the specific substances have been removed by passing through the adsorbent. As shown in FIG. 3, the return liquid flowing out from the plasma outflow port 22A is transported to the blood return circuit 3 via the return liquid circuit 4, mixed with the blood cell components flowing out from the blood cell outflow port 12 of the first blood purifier 10, and returned to the patient P via the blood outlet section 3a.

[0061] 4 shows a control method for the blood purification apparatus 1A according to this embodiment (a plasma recovery method using the blood purification apparatus 1A). The control method according to this embodiment is substantially the same as the control method according to the first embodiment, and therefore a detailed description thereof will be omitted.

[0062] The blood purification apparatus 1A according to the embodiment described above can achieve the same effects as those of the blood purification apparatus 1 according to the first embodiment. That is, it is possible to perform a "downstream recovery control" for recovering plasma contained in the filtrate present in the downstream region of the intermediate circuit 30, a "first upstream recovery control" for recovering plasma contained in the filtrate present in the upstream region of the intermediate circuit 30, and a "second upstream recovery control" for recovering plasma contained in the filtrate present outside the filtration membrane in the first blood purifier 10. Therefore, even in a case where the second blood purifier 20A is clogged and a relatively long time is required for the "downstream recovery control", the "first upstream recovery control" or the "second upstream recovery control" that requires a relatively long time can be performed simultaneously with the "downstream recovery control" (for example, when the capacity of the filtration membrane of the first blood purifier 10 is relatively large, the "second upstream recovery control" requires a relatively long time, and when the capacity of the filtration membrane is relatively small, the "first upstream recovery control" requires a relatively long time). This allows the total time required for plasma recovery to be shortened.

[0063] Moreover, in the blood purification apparatus 1A according to the embodiment described above, the order of performing the "downstream collection control", the "first upstream collection control", and the "second upstream collection control" can be changed depending on predetermined conditions (e.g., the capacity and type of the filtration membrane of the first blood purifier 10). Therefore, by setting various collection patterns depending on the conditions, it is possible to contribute to further shortening the plasma collection time.

[0064] In the blood purification apparatus 1A according to the embodiment described above, the control unit 80 can control the pump 40, the first gas supply unit 50, and the second gas supply unit 70 so that the total flow rate of plasma collected when the "downstream collection control", "first upstream collection control", and "second upstream collection control" are performed is equal to or less than a predetermined threshold. Therefore, the total flow rate of plasma collected can be suppressed to be equal to or less than a predetermined threshold, making it possible to suppress adverse effects on the patient P caused by a sudden increase in the amount of returned blood.

[0065] The present invention is not limited to the above-described embodiments, and even if a person skilled in the art appropriately modifies the design of these embodiments, the same is included within the scope of the present invention as long as the features of the present invention are included. In other words, the elements of the above-described embodiments and their arrangements, materials, conditions, shapes, sizes, etc. are not limited to those exemplified, and can be appropriately modified. In addition, the elements of the above-described embodiments can be combined to the extent technically possible, and combinations of these can also be included within the scope of the present invention as long as they include the features of the present invention. [Explanation of symbols]

[0066] 1·1A…Blood purification device 2. Blood collection circuit 3…Blood return circuit 10. The first blood purifier 20·20A…Second blood purifier 30…Intermediate circuit 31…First air supply point 40…Pump 50…First air supply section 60...Air supply path 61...Second air supply point 70...Second air supply section 80...Control unit

Claims

1. A blood purification apparatus comprising: a first blood purifier which produces a filtrate containing plasma by filtering blood; a second blood purifier which further filters the filtrate supplied from the first blood purifier or which adsorbs plasma contained in the filtrate to produce a return liquid; a pump which is provided in an intermediate circuit connecting the first blood purifier and the second blood purifier and which transports the filtrate from the first blood purifier to the second blood purifier; an air supply unit which is capable of supplying air to an air supply point located downstream of the pump in the intermediate circuit; and a control unit which controls the pump and the air supply unit, wherein blood collected via a blood collection circuit is returned via a blood return circuit by passing through the first blood purifier and the second blood purifier by driving the pump in a forward direction using the control unit, The control unit is a downstream recovery control in which the filtrate present in a region downstream of the air supply point in the intermediate circuit is sent to the blood return circuit via the second blood purifier by supplying air to the air supply point by the air supply unit; an upstream recovery control in which the filtrate present in a region upstream of the air supply point in the intermediate circuit is sent to the blood return circuit via the first blood purifier by driving the pump in the reverse direction while supplying air to the air supply point by the air supply unit, and is recovered; and controlling the pump and the air supply unit so that both of the above are performed with an overlap of at least a predetermined time.

2. The blood purification apparatus according to claim 1 , wherein the control unit controls the pump and the air supply unit so as to simultaneously perform the downstream recovery control and the upstream recovery control.

3. The blood purification apparatus according to claim 2 , wherein the control unit sets a flow rate of the pump smaller than a flow rate of the air supply unit.

4. a first blood purifier which produces a filtrate containing plasma by filtering blood; a second blood purifier which further filters the filtrate supplied from the first blood purifier or adsorbs plasma contained in the filtrate to produce a return liquid; a pump which is provided in an intermediate circuit connecting the first blood purifier and the second blood purifier and which transports the filtrate from the first blood purifier to the second blood purifier; a first air supply unit which can supply air to a first air supply point which is provided downstream of the pump in the intermediate circuit; an air supply path which is connected to a port of the first blood purifier to which the intermediate circuit is not connected; a second air supply unit which is provided at a second air supply point which is provided in the air supply path; and a control unit which controls the pump, the first air supply unit, and the second air supply unit, The control unit is a downstream recovery control in which the filtrate present in a region downstream of the first air supply point in the intermediate circuit is sent to the blood return circuit via the second blood purifier by supplying air to the first air supply point by the first air supply unit, and is recovered; a first upstream recovery control in which the filtrate present in a region upstream of the first air supply point in the intermediate circuit is sent to the blood return circuit via the first blood purifier by driving the pump in the reverse direction while supplying air to the first air supply point by the first air supply unit, and is recovered; a second upstream recovery control in which the filtrate present on the outside of the filtration membrane in the first blood purifier is sent to the blood return circuit and recovered by supplying air to the second air supply point by the second air supply unit; The blood purification apparatus controls the pump, the first gas supply unit, and the second gas supply unit so as to carry out the above.

5. 5. The blood purification apparatus according to claim 4, wherein the control unit controls the pump, the first gas supply unit, and the second gas supply unit so as to change an order in which the downstream recovery control, the first upstream recovery control, and the second upstream recovery control are performed in accordance with a predetermined condition.

6. 6. The blood purification apparatus according to claim 5, wherein the predetermined condition is the type of the filtration membrane of the first blood purifier.

7. The blood purification apparatus according to claim 5 , wherein the control unit controls the pump and the first air supply unit so as to simultaneously perform the downstream recovery control and the first upstream recovery control.

8. The blood purification apparatus according to claim 7 , wherein the control unit sets a flow rate of the pump smaller than a flow rate of the first air supply unit.

9. 8. The blood purification apparatus according to claim 7, wherein the control unit controls the pump, the first gas supply unit, and the second gas supply unit so that the second upstream recovery control is performed before the downstream recovery control and the first upstream recovery control.

10. 8. The blood purification apparatus according to claim 7, wherein the control unit controls the pump, the first gas supply unit, and the second gas supply unit so that the second upstream recovery control is performed after the downstream recovery control and the first upstream recovery control.

11. The blood purification apparatus according to claim 5 , wherein the control unit controls the pump and the second air supply unit so as to simultaneously perform the downstream recovery control and the second upstream recovery control.

12. The blood purification apparatus according to claim 11 , wherein the control unit stops the pump when the downstream recovery control and the second upstream recovery control are simultaneously performed.

13. The blood purification apparatus according to claim 11, wherein the control unit controls the pump, the first gas supply unit, and the second gas supply unit so that the first upstream recovery control is performed before the downstream recovery control and the second upstream recovery control.

14. The blood purification apparatus according to claim 11, wherein the control unit controls the pump, the first gas supply unit, and the second gas supply unit so that the first upstream recovery control is performed after the downstream recovery control and the second upstream recovery control.

15. 6. The blood purification apparatus according to claim 5, wherein the control unit controls the pump, the first gas supply unit, and the second gas supply unit so as to simultaneously perform the downstream recovery control, the first upstream recovery control, and the second upstream recovery control.

16. 16. The blood purification apparatus according to claim 4, wherein the control unit controls the pump, the first gas supply unit, and the second gas supply unit so that a total flow rate of plasma recovered when the downstream recovery control, the first upstream recovery control, and the second upstream recovery control are performed is equal to or less than a predetermined threshold value.

17. A method for controlling a blood purification apparatus comprising: a first blood purifier which produces a filtrate containing plasma by filtering blood; a second blood purifier which further filters the filtrate supplied from the first blood purifier or which adsorbs plasma contained in the filtrate to produce a return liquid; a pump which is provided in an intermediate circuit connecting the first blood purifier and the second blood purifier and which transports the filtrate from the first blood purifier to the second blood purifier; an air supply unit which is capable of supplying air to an air supply point located downstream of the pump in the intermediate circuit; and a control unit, wherein the control unit drives the pump in a forward direction to return blood collected via a blood collection circuit through the first blood purifier and the second blood purifier, a downstream recovery control step of controlling the air supply unit by the control unit so that the filtrate present in a region downstream of the air supply unit in the intermediate circuit is sent to the blood return circuit via the second blood purifier and recovered by supplying air to the air supply point by the air supply unit; an upstream recovery control step of controlling the air supply unit and the pump by the control unit so that the filtrate present in a region upstream of the air supply point in the intermediate circuit is sent to the blood return circuit via the first blood purifier by driving the pump in the reverse direction while supplying air to the air supply point by the air supply unit; The blood purification apparatus control method includes performing both of the above steps so that they overlap for at least a predetermined period of time.

18. a first blood purifier which produces a filtrate containing plasma by filtering blood; a second blood purifier which further filters the filtrate supplied from the first blood purifier or adsorbs plasma contained in the filtrate to produce a return liquid; a pump which is provided in an intermediate circuit connecting the first blood purifier and the second blood purifier and which transports the filtrate from the first blood purifier to the second blood purifier; a first air supply unit capable of supplying air to a first air supply point located downstream of the pump in the intermediate circuit; an air supply path connected to a port of the first blood purifier to which the intermediate circuit is not connected; a second air supply unit provided at a second air supply point located in the air supply path; and a control unit, wherein the control unit drives the pump in a forward direction to return blood collected via a blood collection circuit through the first blood purifier and the second blood purifier, a downstream recovery control step of controlling the first air supply unit by the control unit so that the filtrate present in a region downstream of the first air supply unit in the intermediate circuit is sent to the blood return circuit via the second blood purifier by supplying air to the first air supply point by the first air supply unit, and recovered; a first upstream recovery control step of controlling the first air supply unit and the pump by the control unit so that the filtrate present in a region upstream of the first air supply point in the intermediate circuit is sent to the blood return circuit via the first blood purifier by driving the pump in the reverse direction while supplying air to the first air supply point by the first air supply unit, and recovered; a second upstream recovery control step of controlling the second air supply unit by the control unit so that the filtrate present outside the filtration membrane in the first blood purifier is sent to the blood return circuit and recovered by supplying air to the second air supply point by the second air supply unit; A method for controlling a blood purification device.

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