Blood purification device

Abstract

To provide a blood purification device for returning blood in a blood circuit to the inside of a body.SOLUTION: A blood purification device includes: a blood circuit and a dialysis fluid circuit connected through a blood purifier; an air introduction passage connected to the dialysis fluid circuit; an air introduction unit provided either to the dialysis fluid circuit or the air introduction passage for bringing the dialysis fluid circuit into positive pressure by introducing air to the dialysis fluid circuit through the air introduction passage; and a control device for controlling the blood circuit and the dialysis fluid circuit so as to return blood in the blood circuit and the blood purifier to the inside of a body by controlling the air introduction unit so that the dialysis fluid flows from the dialysis fluid circuit to the blood circuit and causing the dialysis fluid to flow from the dialysis fluid circuit to the blood circuit.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a blood purification device, and more particularly to a blood purification device that uses dialysate in a dialysate filter to return blood remaining in a blood circuit to the body. [Background technology]

[0002] When the kidneys, which are part of the human body, stop functioning normally (renal failure), they are no longer able to convert excess fluid into urine and excrete unnecessary waste products from the body. To treat kidney failure, a blood purification device (dialysis device) is used to circulate the patient's blood outside the body and filter out waste products and fluids from the blood using a blood purifier (dialysis treatment).

[0003] A blood purification device draws blood from a patient and introduces the blood into a blood purifier (blood flow path) through a blood circuit, while also introducing dialysate from a dialysate supply source (dialysate supply unit) through a dialysate circuit into the blood purifier (dialysate flow path). The blood purification device then purifies the blood by exchanging components such as waste products and electrolytes between the blood and the dialysate via the blood purifier, and returns the purified blood to the body. Since blood remains in the blood circuit after dialysis treatment, it is common to return the remaining blood to the body (blood return) by flowing saline through the blood circuit. Dialysate is sometimes used as a substitute for saline. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5693890 Summary of the Invention [Problem to be solved by the invention]

[0005] Patent Document 1 discloses a blood purification device that returns blood in a blood circuit to the body by supplying dialysate in a filter to the blood circuit. The blood purification device described in Patent Document 1 introduces air into the filter through an air inlet line, and draws the dialysate in the filter into the blood circuit by rotating a blood pump powered by a backup battery. This configuration allows blood return even if the power supply to the blood purification device is stopped.

[0006] In the blood purification device described in Patent Document 1, the tip of the air introduction line is opened to air, and the blood pump is rotated to draw dialysate from the blood circuit. Therefore, the pressure generated by the rotation of the blood pump may cause negative pressure in the circuit on the inlet side of the blood pump, which is undesirable for returning blood.

[0007] An object of the present invention is to provide a blood purification device that returns blood to a patient while preventing or alleviating negative pressure in the blood circuit. [Means for solving the problem]

[0008] The blood purification device according to the embodiment comprises a blood circuit and a dialysate circuit connected via a blood purifier, an air introduction path connected to the dialysate circuit, an air introduction unit provided in the dialysate circuit or the air introduction path and introducing air into the dialysate circuit via the air introduction path to create a positive pressure in the dialysate circuit, and a control device that controls the air introduction unit so that the dialysate flows from the dialysate circuit to the blood circuit, and controls the blood circuit and the dialysate circuit so that the blood in the blood circuit and the blood purifier is returned to the body by flowing the dialysate from the dialysate circuit to the blood circuit.

[0009] In another embodiment, a method performed by a blood purification device includes a blood circuit and a dialysate circuit connected via a blood purifier, an air introduction channel connected to the dialysate circuit, an air introduction unit provided in the dialysate circuit or the air introduction channel and introducing air into the dialysate circuit via the air introduction channel to create a positive pressure in the dialysate circuit, and a control device, and includes the steps of: controlling the air introduction unit by the control device to cause the dialysate to flow from the dialysate circuit to the blood circuit; and controlling the blood circuit and the dialysate circuit to return blood in the blood circuit and the blood purifier to the body by causing the dialysate to flow from the dialysate circuit to the blood circuit. [Effects of the Invention]

[0010] According to the blood purification device of the embodiment, it is possible to prevent the blood circuit from becoming negative pressure or to alleviate the negative pressure state. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an overall configuration diagram of a blood purification device according to a first embodiment. [Figure 2] FIG. 10 is a diagram showing the relationship between the air introduction part and a chamber in the blood circuit. [Figure 3] FIG. 10 is a diagram showing the flow of dialysate in a backfiltration type blood return process (forward fluid flow) using the dialysate in the (primary) dialysate filter. [Figure 4] FIG. 10 is a diagram showing the flow of dialysate in a backfiltration type blood return process (forward fluid flow) using dialysate in a (secondary) dialysate filter. [Figure 5] FIG. 10 is a diagram showing the flow of dialysate in a backfiltration type blood return process (reverse fluid feeding direction) using the dialysate in the (primary) dialysate filter. [Figure 6] FIG. 1 is a diagram showing the overall configuration of a blood purification device according to a second embodiment. [Figure 7]FIG. 10 is a diagram showing the flow of dialysate in a fluid replacement type blood return process (forward fluid flow) using the dialysate in the (primary) dialysate filter. [Figure 8] FIG. 10 is a diagram showing the flow of dialysate in a fluid replacement type blood return process (reverse fluid feeding direction) using the dialysate in the (primary) dialysate filter. [Figure 9] FIG. 10 is a diagram showing the overall configuration of a blood purification device according to a third embodiment. [Figure 10] FIG. 10 is a diagram showing the flow of dialysate in a backfiltration type blood return process (forward fluid flow) using the dialysate in the (primary) dialysate filter. [Figure 11] FIG. 10 is a diagram showing the flow of dialysate in a backfiltration type blood return process (forward fluid flow) using the dialysate in the (primary) dialysate filter. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a blood purification device (dialysis device) according to an embodiment will be described with reference to the accompanying drawings. When the power supply from the main power source to the blood purification device is stopped due to a power outage or the like, the blood purification device according to the embodiment uses the dialysate in the dialysate filter to return blood remaining in the dialysate-blood circuit to the body (blood return). To perform this blood return, some components of the blood purification device operate using power supplied from a backup power source.

[0013] First Embodiment Figure 1 is a block diagram showing the configuration of a blood purification apparatus 100 according to a first embodiment. The blood purification apparatus 100 includes, as its main components, a blood purifier 1, a blood circuit 2, a dialysate circuit 3, a replacement fluid circuit 4, a blood pump 5, a dialysate supply unit 6, a primary air inlet unit 7, a secondary air inlet unit 8, a duplex pump 9, dialysate filters 10 and 11, a control device 12, and a backup power supply 13. The components shown in Figure 1 are merely examples of components for implementing this embodiment. In practice, the apparatus may also include a chamber for capturing air bubbles in the blood flowing through the blood circuit 2, as well as a water removal line and a water removal pump for removing water from the patient's blood.

[0014] The blood purifier 1, also called a dialyzer, purifies the patient's blood. The blood purifier 1 includes a blood inlet 1a through which blood is introduced from a blood circuit 2 and a blood outlet 1b through which purified blood is discharged. The blood purifier 1 also includes a dialysate inlet 1c through which dialysate is introduced from a dialysate circuit 3 and a dialysate outlet 1d through which dialysate (effluent) is discharged. The blood purifier 1 also includes a blood purification membrane provided therein. The blood purification membrane is composed of a bundle of hollow fibers (hollow fiber membranes) with holes in their side walls. The inside of the blood purification membrane is the blood flow path (not shown), and the outside of the blood purification membrane (hollow fiber) is the dialysate flow path (not shown).

[0015] Blood flowing through the blood purifier 1 flows through the blood flow path, and unnecessary substances such as uremic toxins are removed by diffusion, ultrafiltration, or both, passing through the pores of the blood purification membrane. The dialysate flowing through the blood purifier 1 passes through the dialysate flow path, and only substances necessary for the human body, such as electrolytes, contained in the dialysate pass through the pores, and are replenished with the blood. It is also possible for the inside of the blood purification membrane to function as the dialysate flow path, and the outside of the blood purification membrane to function as the blood flow path.

[0016] The blood circuit 2 and the dialysate circuit 3 are connected via the blood purification membrane of the blood purifier 1, allowing the blood and dialysate to circulate mutually. The blood circuit 2 is a flow path that introduces blood removed from a patient into the blood purifier 1 during dialysis treatment and returns blood (purified blood) extracted from the blood purifier 1 to the body (blood flows in the direction indicated by arrow A in Figure 1). The blood circuit 2 is mainly composed of tubes that allow blood to pass through. The blood circuit 2 includes a blood removal side circuit 2a and a blood return side circuit 2b.

[0017] The blood removal side circuit 2a is a flow path that introduces blood removed from a patient into the blood purifier 1. One end of the blood removal side circuit 2a is attached to a blood removal side puncture needle (not shown) inserted into the patient's blood vessel, and the other end is connected to the blood inlet port 1a. The blood removal side circuit 2a is provided with an on-off valve (solenoid valve) V1. The flow of blood in the blood removal side circuit 2a is controlled by opening and closing the on-off valve V1. The blood return side circuit 2b is a flow path that returns blood withdrawn from the blood purifier 1 to the body. One end of the blood return side circuit 2b is attached to a blood return side puncture needle (not shown) inserted into the patient's blood vessel, and the other end is connected to the blood outlet port 1b. The blood return side circuit 2b is provided with an on-off valve (solenoid valve) V2. The flow of blood in the blood return side circuit is controlled by opening and closing the on-off valve V2.

[0018] The blood pump 5 is provided in the blood removal side circuit 2a and pumps the liquid in the blood circuit 2 in a direction from the blood removal side circuit 2a to the blood return side circuit 2b (hereinafter referred to as the forward liquid transport direction) or from the blood return side circuit 2b to the blood removal side circuit 2a (hereinafter referred to as the reverse liquid transport direction). The blood pump 5 is a peristaltic pump having a stator and a rotor, and drives the rotor to rotate. The rotor is rotated by an actuator (not shown) such as an electric motor under the control of the control device 12. The blood pump 5 is provided with a rotary encoder (not shown). The rotary encoder detects the rotation speed of the rotor. When the blood pump 5 rotates forward, it squeezes the blood removal side circuit 2a, which is sandwiched between the stator and the rotor, causing a flow in the forward liquid transport direction. When the blood pump 5 rotates reversely, it squeezes the blood removal side circuit 2a, causing a flow in the reverse liquid transport direction.

[0019] The dialysate circuit 3 is a flow path that supplies dialysate to the blood purifier 1 and / or the blood circuit 2 and discharges the dialysate from the blood purifier 1. The dialysate circuit 3 is mainly composed of tubes through which the dialysate can pass. The dialysate circuit 3 includes a dialysate introduction circuit 3a, a dialysate discharge circuit 3b, a dialysate bypass circuit 3c, and a dialysate bypass circuit 3d.

[0020] The dialysate introduction circuit 3a is a flow path from the dialysate supply unit 6 to the dialysate inlet 1c. The dialysate flows through the blood purifier 1 via the dialysate introduction circuit 3a. The dialysate introduction circuit 3a is provided with an on-off valve (solenoid valve) V3, an on-off valve (solenoid valve) V4, and a dialysate port P. The flow of dialysate to the blood purifier 1 is controlled by opening and closing the on-off valves V3 and V4. The dialysate port P takes out the dialysate.

[0021] The dialysate discharge circuit 3b is a flow path from the dialysate outlet 1d to a dialysate discharge unit (not shown). The dialysate discharge circuit 3b discharges the drained fluid from the blood purifier 1 to the dialysate discharge unit. The dialysate discharge circuit 3b is provided with an on-off valve (solenoid valve) V6. The flow of drained fluid to the dialysate discharge unit is controlled by opening and closing the on-off valve V6.

[0022] The dialysate bypass circuit 3c and the dialysate bypass circuit 3d are each a flow path from the dialysate inlet circuit 3a to the dialysate outlet circuit 3b. An on-off valve (solenoid valve) V7 is provided in the dialysate bypass circuit 3c. Similarly, an on-off valve (solenoid valve) V8 is provided in the dialysate bypass circuit 3d. The flow of dialysate from the dialysate inlet circuit 3a to the dialysate outlet circuit 3b is controlled by opening and closing the on-off valves V7 and V8.

[0023] The dialysate bypass circuit 3c and the dialysate bypass circuit 3d are flow paths for preventing inappropriate dialysate from flowing into the blood circuit 2. For example, the blood purification device 100 is provided with a heater (not shown) for heating the dialysate, and if the dialysate temperature exceeds a predetermined value due to the heater during dialysis treatment, the dialysate flows into the dialysate discharge circuit 3b through the dialysate bypass circuit 3c and / or the dialysate bypass circuit 3d to prevent the high-temperature dialysate from flowing into the blood circuit 2. In this case, the on-off valves V7 and / or V8 are opened.

[0024] The replacement fluid circuit 4 is a connecting flow path that bypasses the blood purifier 1 and connects the blood circuit 2 and the dialysate circuit 3. Specifically, the replacement fluid circuit 4 is a flow path from the dialysate port P to the blood removal side circuit 2a, for supplying dialysate from the dialysate circuit 3 to the blood circuit 2, bypassing the blood purifier 1. The replacement fluid circuit 4 is provided with an on-off valve (solenoid valve) V5. The flow of dialysate to the blood removal side circuit 2a is controlled by opening and closing the on-off valve V5.

[0025] The dialysate supply unit 6 introduces the dialysate into the dialysate introducing circuit 3a. The dialysate supply unit 6 receives a supply of pure water from a pure water production system (RO water production system) (not shown) provided outside the blood purification apparatus 100, and receives (intakes) a supply of undiluted solution from a undiluted solution tank (not shown) externally mounted on the blood purification apparatus 100. Next, the dialysate supply unit 6 prepares the dialysate by mixing the undiluted solution of the dialysate with pure water at a predetermined ratio, and introduces the dialysate into the dialysate introducing circuit 3a. In this embodiment, the blood purification apparatus 100 includes the dialysate supply unit 6. However, the present invention is not limited to this. The dialysate supply unit 6 may be provided externally as a dialysate supply device, and the blood purification apparatus may receive a supply of dialysate from the dialysate supply device.

[0026] The dialysate supply unit 6 normally generates dialysate (for example, during dialysis treatment) and introduces it into the dialysate introducing circuit 3a. However, during a power outage or other such event, the production of new dialysate may be restricted. In this case, the supply of dialysate from the dialysate supply unit 6 to the dialysate circuit 3 is stopped, and instead, the dialysate stored in the dialysate filter 10 and / or the dialysate filter 11 is introduced into the dialysate circuit 3. This will be described in detail later.

[0027] The primary air introduction section 7 introduces air into the (primary) dialysate filter 10, which will be described later. Air is introduced into the dialysate filter 10 by the primary air introduction section 7. When air is introduced into the dialysate filter 10, the dialysate filter 10 becomes under positive pressure, and the dialysate stored in the dialysate filter 10 flows into the dialysate circuit 3 (dialysate port P). In other words, the primary air introduction section 7 serves to push the dialysate stored in the dialysate filter 10 into the dialysate circuit 3, causing it to flow into the dialysate circuit 3 (dialysate introduction circuit 3a) and the blood circuit 2.

[0028] The primary air introduction unit 7 includes an air pump 7a, an air introduction passage 7b, an on-off valve (solenoid valve) 7c, an air filter 7d, and an air filter 7e. The air pump 7a has a rotor therein and is driven to rotate the rotor. The rotor is rotated by an actuator (not shown) such as an electric motor under the control of the control device 12. The air pump 7a is provided with a rotary encoder (not shown). The rotary encoder detects the number of rotations of the rotor. As the air pump 7a rotates, air is introduced into the dialysate filter 10 through the air introduction passage 7b.

[0029] Air introduced into the dialysate filter 10 by driving the air pump 7a causes the dialysate to flow into the dialysate circuit 3 (dialysate introduction circuit 3a) and the blood circuit 2. The flow of air into the dialysate filter 10 is controlled by opening and closing an on-off valve 7c provided between the air pump 7a and the dialysate filter 10. Air filters 7d and 7e remove dust particles from the air.

[0030] The secondary air introduction part 8 introduces air into the (secondary) dialysate filter 11, which will be described later. Air is introduced into the dialysate filter 11 by the secondary air introduction part 8. When air is introduced into the dialysate filter 11, the dialysate filter 11 becomes under positive pressure, and the dialysate stored in the dialysate filter 11 flows into the dialysate circuit 3 (dialysate port P). In other words, the secondary air introduction part 8 plays a role in pushing the dialysate stored in the dialysate filter 11 out into the dialysate circuit 3, causing it to flow into the dialysate circuit 3 (dialysate introduction circuit 3a) and the blood circuit 2.

[0031] The secondary air introduction unit 8 includes an air pump 8a, an air introduction passage 8b, an on-off valve (solenoid valve) 8c, an air filter 8d, and an air filter 8e. The air pump 8a has a rotor therein and is driven to rotate. The rotor is rotated by an actuator (not shown) such as an electric motor under the control of the control device 12. The air pump 8a is provided with a rotary encoder (not shown). The rotary encoder detects the rotation speed of the rotor. As the air pump 8a rotates, air is introduced into the dialysate filter 11 through the air introduction passage 8b.

[0032] Air introduced into dialysate filter 11 by driving air pump 8a causes the dialysate to flow into dialysate circuit 3 (dialysate introducing circuit 3a) and blood circuit 2. The flow of air into dialysate filter 11 is controlled by opening and closing on-off valve 8c provided between air pump 8a and dialysate filter 11. Air filters 8d and 8e remove dust particles from the air.

[0033] Either or both of the primary air introduction unit 7 (air pump 7a) and the secondary air introduction unit 8 (air pump 8a) serve to adjust the liquid level in a chamber provided in the blood circuit 2, for example, during dialysis treatment. This liquid level adjustment will be described later.

[0034] It should be noted that the on-off valve 7c, air filter 7d, and air filter 7e are not essential components of the primary air introduction section 7. Similarly, the on-off valve 8c, air filter 8d, and air filter 8e are not essential components of the secondary air introduction section 8.

[0035] The duplex pump 9 is provided across the dialysate inlet circuit 3a and the dialysate outlet circuit 3b. The duplex pump 9 introduces the dialysate into the dialysate inlet circuit 3a downstream in the fluid supply direction, while discharging the waste dialysate into the dialysate outlet circuit 3b downstream in the fluid supply direction. That is, the duplex pump 9 serves as a dialysate supply pump for supplying the dialysate to the blood circuit 2, and a dialysate discharge pump for discharging the dialysate from the dialysate discharge section. A plunger (not shown) is provided inside the housing of the duplex pump 9. The volume is divided into a volume on the dialysate inlet circuit 3a side and a volume on the dialysate outlet circuit 3b side, with the plunger sandwiching the volume between the introduction of the dialysate and the discharge of the waste dialysate.

[0036] The dialysate filter 10 purifies the dialysate by capturing substances such as endotoxins contained in the dialysate supplied from the dialysate supply unit 6. The dialysate filter 10 is provided in the dialysate circuit 3 and includes a primary chamber 10a and a secondary chamber 10b. The dialysate filter 10 also has a dialysate purification membrane provided therein. The dialysate purification membrane is composed of a bundle of hollow fibers (hollow fiber membranes) having holes in their side walls. The dialysate filter 10 is configured so that the dialysate flows from the primary chamber 10a (inside the dialysate purification membrane) to the secondary chamber 10b (outside the dialysate purification membrane). The dialysate filter 10 has the property of not allowing air to pass through it when water passes through it due to the surface tension of water molecules.

[0037] The primary chamber 10a and the secondary chamber 10b are capable of storing dialysate supplied from the dialysate supply unit 6. That is, during dialysis treatment, the primary chamber 10a stores the dialysate to be purified, and the secondary chamber 10b stores the purified dialysate. This stored dialysate is supplied to the dialysate circuit 3 by the primary air introduction unit 7, as will be described later. Note that the primary chamber 10a may be located outside the dialysate purification membrane, and the secondary chamber 10b may be located inside the dialysate purification membrane.

[0038] The dialysate filter 11 purifies the dialysate by capturing substances such as endotoxins contained in the dialysate supplied from the dialysate supply unit 6. The dialysate filter 11 is provided in the dialysate circuit 3 and includes a primary chamber 11a and a secondary chamber 11b. The dialysate filter 11 also has a dialysate purification membrane provided therein. The dialysate purification membrane is composed of a bundle of hollow fibers (hollow fiber membranes) having holes in their side walls. The dialysate filter 11 is configured so that the dialysate flows from the primary chamber 11a (inside the dialysate purification membrane) to the secondary chamber 11b (outside the dialysate purification membrane). The dialysate filter 11 has the property of not allowing air to pass through it due to the surface tension of water molecules when water is passed through it.

[0039] The primary chamber 11a and the secondary chamber 11b are capable of storing dialysate supplied from the dialysate supply unit 6. That is, during dialysis treatment, the primary chamber 11a stores the dialysate to be purified, and the secondary chamber 11b stores the purified dialysate. As will be described later, this stored dialysate is supplied to the dialysate circuit 3 by the secondary air introduction unit 8. Note that the primary chamber 11a may be located outside the dialysate purification membrane, and the secondary chamber 11b may be located inside the dialysate purification membrane.

[0040] Filtration filters such as dialysate filter 10 and dialysate filter 11 are generally provided in blood purification devices to remove impurities contained in the dialysate during dialysis treatment. In this embodiment, two dialysate filters 10 and 11 are provided in the dialysate circuit 3, so that the dialysate can be purified even when one of them is not functioning.

[0041] The control device 12 is a processing device that controls the entire blood purification apparatus 100, including the air pumps 7a and 8a. The control device 12 includes an arithmetic unit and a memory device (memory devices such as RAM and ROM). The arithmetic unit may be implemented as a processor such as a CPU or a microcontroller, an ASIC (Application Specific Integrated Circuit), or an FPGA (Field Programmable Gate Array), but the type of the arithmetic unit is not limited.

[0042] The backup power supply 13 is a power supply device that supplies power to some of the components, such as the control device 12, when the power supply from the main power supply (not shown) to the blood purification device 100 is stopped, for example, during a power outage. As will be described later, the backup power supply 13 enables the control device 12, primary air introduction section 7, secondary air introduction section 8, etc. to function, and blood remaining in the blood circuit 2 can be returned to the body.

[0043] In the above-described blood purification apparatus 100, during dialysis treatment, the duplex pump 9 operates to introduce dialysate from the dialysate supply unit 6 into the dialysate inlet circuit 3a, and then flows from the dialysate circuit 3 through the replacement fluid circuit 4 to the blood purifier 1. The dialysate then passes from the blood purifier 1 through the dialysate outlet circuit 3b and is discharged from the dialysate outlet. During dialysis treatment, the blood pump 5 rotates forward, causing blood to flow in the forward fluid supply direction. As a result of the flow of dialysate during the above-described dialysis treatment, purified dialysate is stored in the dialysate filters 10 and 11.

[0044] Next, with reference to FIG. 2, the relationship between the primary air introduction unit 7, the secondary air introduction unit 8, and the chambers provided in the blood circuit 2 will be described. As described above, either or both of the primary air introduction unit 7 and the secondary air introduction unit 8 play a role in adjusting the liquid level in the chambers provided in the blood circuit 2, for example, during dialysis treatment. In other words, the air pump 7a and / or the air pump 8a also function as a liquid level adjustment pump (a liquid level adjustment pump is not normally used for blood return). FIG. 2 shows the state when the air pump 7a and the air pump 8a function as a liquid level adjustment pump. Note that the air pump 7a and the air pump 8a do not also function as a liquid level adjustment pump, and the air pump 7a and the air pump 8a may be provided as independent liquid level adjustment pumps.

[0045] In the blood circuit 2, a blood removal-side air trap chamber 2c is provided in the blood removal-side circuit 2a, and a blood return-side air trap chamber 2d is provided in the blood return-side circuit 2b. The blood removal-side air trap chamber 2c is provided primarily for the purpose of trapping air to prevent air from flowing into the blood purifier 1 and causing an airlock. The blood return-side air trap chamber 2d is provided primarily for the purpose of trapping air to prevent air from flowing into the patient's body through the blood circuit 2. It is not necessary to provide both the blood removal-side air trap chamber 2c and the blood return-side air trap chamber 2d; only one of them may be provided. In other words, the blood removal-side air trap chamber 2c and the blood return-side air trap chamber 2d serve as chambers that store blood within the blood circuit 2.

[0046] The blood removal-side air trap chamber 2c is connected to a secondary air introduction section 8, with an on-off valve (solenoid valve) V9 provided therebetween. The flow of air from the secondary air introduction section 8 to the blood removal-side air trap chamber 2c is controlled by opening and closing the on-off valve V9 (the secondary air introduction section 8 flows air into the blood removal-side air trap chamber 2c). The blood return-side air trap chamber 2d is connected to a primary air introduction section 7, with an on-off valve (solenoid valve) V10 provided therebetween. The flow of air from the primary air introduction section 7 to the blood return-side air trap chamber 2d is controlled by opening and closing the on-off valve V10 (the primary air introduction section 7 flows air into the blood return-side air trap chamber 2d).

[0047] The blood removal-side air trap chamber 2c and the blood return-side air trap chamber 2d each have two layers: a blood layer and an air layer. If air accumulates in the chamber, the liquid level will drop, potentially causing an airlock in which air enters the hollow fibers of the blood purifier 1. In the example shown in Figure 2, the primary air introduction unit 7 (air pump 7a) rotates forward to introduce air into the blood return-side air trap chamber 2d, lowering the liquid level, and rotates backward to expel air from the blood return-side air trap chamber 2d, raising the liquid level. Similarly, the secondary air introduction unit 8 (air pump 8a) rotates forward to introduce air into the blood removal-side air trap chamber 2c, lowering the liquid level, and rotates backward to expel air from the blood removal-side air trap chamber 2c, raising the liquid level.

[0048] 2 shows an example in which the blood removal-side air trap chamber 2c is connected to the secondary air introduction part 8 and the blood return-side air trap chamber 2d is connected to the primary air introduction part 7, but this connection is merely an example. For example, the blood removal-side air trap chamber 2c may be connected to the primary air introduction part 7 and the blood return-side air trap chamber 2d may be connected to the secondary air introduction part 8, or both the blood removal-side air trap chamber 2c and the blood return-side air trap chamber 2d may be connected to the primary air introduction part 7 or the secondary air introduction part 8.

[0049] Next, processing according to the first embodiment will be described with reference to FIGS. 3 to 5. In the first embodiment, when the power supply from the main power source to the blood purification device 100 is stopped due to a power outage or the like, the blood remaining in the blood purifier 1 and the blood circuit 2 is returned to the body using the dialysate in the dialysate filters 10 and 11 (by sequentially introducing air into the dialysate filters 10 and 11). When the power supply from the main power source to the blood purification device 100 is stopped, only some components of the blood purification device 100 (described later) function using power supplied from the backup power source 13, but the production and supply of dialysate by the dialysate supply unit 6 stops. At this time, the air pump 7a serves to flow the dialysate in the dialysate filter 10 into the blood circuit 2, rather than adjusting the liquid level in the blood return-side air trap chamber 2d. Similarly, the air pump 8a serves to flow the dialysate in the dialysate filter 11 into the blood circuit 2, rather than adjusting the liquid level in the blood removal-side air trap chamber 2c.

[0050] Furthermore, in the first embodiment, a blood return method is used in which the dialysate is introduced from the dialysate circuit 3 to the blood circuit 2 through the blood purification membrane of the blood purifier 1, and the dialysate pushes out the blood in the blood purifier 1 and the blood circuit 2, thereby returning the blood to the body. Hereinafter, this blood return method will be referred to as a backfiltration blood return process. In the backfiltration blood return process, the dialysate flows through the dialysate circuit 3 and then passes from the dialysate circuit 3 through the blood purifier 1. This flow of the dialysate causes the dialysate to pass through the dialysate flow path of the blood purifier 1, push out the blood through the pores in the blood purification membrane, and return the blood to the body.

[0051] Figure 3 shows the flow of dialysate when a backfiltration blood return process is performed using the dialysate in the dialysate filter 10. In the example shown in Figure 3, blood is returned to the body in the forward flow direction during the backfiltration blood return process. In the following figures, when the on-off valves (V1 to 6, 7c, and 8c) are open, the on-off valves shown in the figures are shaded, and when the on-off valves are closed, the on-off valves shown in the figures are white.

[0052] As shown in FIG. 3, during the backfiltration blood return process (forward solution flow), on-off valves 7c, V3, V4, and V2 are opened. Furthermore, air pump 7a rotates forward. The opening of these on-off valves and the rotation of air pump 7a are controlled by instructions from control device 12. In particular, control device 12 controls the number of revolutions per unit time of air pump 7a so as to generate a flow of dialysate into dialysate circuit 3 (dialysate introduction circuit 3a) and blood circuit 2. In other words, control device 12 controls the flow rate of air from primary air introduction section 7. Although not shown, on-off valve V10 shown in FIG. 2 is closed.

[0053] By driving the air pump 7a and opening the on-off valve 7c, air is introduced into the dialysate filter 10, and a positive pressure is created in the primary chamber 10a of the dialysate filter 10. As a result, the dialysate in the primary chamber 10a reaches the secondary chamber 10b and flows through the dialysate introducing circuit 3a. In other words, the control device 12 controls the dialysate circuit 3 and the blood circuit 2 so that the dialysate flows through the flow paths shown in FIG. 3.

[0054] By opening on-off valves V3, V4, and V2, the dialysate passes through the dialysate introducing circuit 3a, the blood purifier 1 (blood purification membrane), and the blood return circuit 2b. In Figure 3, this flow of the dialysate is indicated by thick chain arrows. Inside the blood purifier 1, the dialysate flows through the dialysate flow path, the blood purification membrane, and the blood flow path in that order. This flow of the dialysate pushes out blood remaining in the blood purifier 1 and the blood circuit 2 (blood return circuit 2b), and the blood is returned to the body.

[0055] 3 is performed by operating at least the control device 12, on-off valve 7c, on-off valve V3, on-off valve V4, on-off valve V2, and air pump 7a using power supplied from backup power supply 13. On the other hand, components such as blood pump 5 and duplex pump 9, which are used to circulate dialysate through dialysate circuit 3 and blood through blood circuit 2 during dialysis treatment, may be stopped.

[0056] When the dialysate in dialysate filter 10 flows, the process switches to a backfiltration type blood return process (forward fluid flow) using the dialysate in dialysate filter 11. That is, in the backfiltration type blood return process (forward fluid flow), the dialysate supply source is switched from dialysate filter 10 to dialysate filter 11. This switching is performed by control device 12, the details of which will be described later. Figure 4 shows the flow of dialysate when the backfiltration type blood return process (forward fluid flow) is performed using the dialysate in dialysate filter 11.

[0057] As shown in FIG. 4, when the dialysate supply source is switched from dialysate filter 10 to dialysate filter 11, on-off valve 7c closes and air pump 7a stops rotating. Meanwhile, air pump 8a rotates forward and on-off valve 8c opens. The opening and closing of these on-off valves, as well as the stopping of air pump 7a and the rotation of air pump 8a, are controlled by instructions from control device 12. In particular, control device 12 controls the number of rotations per unit time of air pump 8a so that dialysate flows into dialysate circuit 3 (dialysate introduction circuit 3a) and blood circuit 2. In other words, control device 12 controls the flow rate of air from secondary air introduction part 8. Although not shown, on-off valve V9 shown in FIG. 2 closes.

[0058] By driving the air pump 8a and opening the on-off valve 8c, air is introduced into the dialysate filter 11, and the primary chamber 11a of the dialysate filter 11 becomes positive pressure. As a result, the dialysate in the primary chamber 11a reaches the secondary chamber 11b and flows through the dialysate introducing circuit 3a. The dialysate then flows through a flow path similar to that shown in Figure 3. That is, the control device 12 controls the dialysate circuit 3 and the blood circuit 2 so that the dialysate flows through the flow path shown in Figure 4. In Figure 4, this flow of dialysate is indicated by thick chain arrows.

[0059] 4 is performed by operating at least the control device 12, on-off valve 8c, on-off valve V3, on-off valve V4, on-off valve V2, and air pump 8a using power supplied from backup power supply 13. Meanwhile, blood pump 5, duplex pump 9, and the like may be stopped.

[0060] To switch the dialysate supply source, the control device 12 determines that the dialysate in the dialysate filter 10 has been introduced (pushed out) into the dialysate circuit 3. This determination may be made by detecting that the primary chamber 10a has become positive pressure. In this case, for example, a pressure gauge is provided in the primary chamber 10a, and the pressure gauge detects the air pressure. The detected pressure value is transmitted to the control device 12. The control device 12 determines whether the pressure value exceeds a predetermined threshold value.

[0061] Alternatively, the above determination may be made by detecting the generation of air bubbles in the dialysis fluid in the primary chamber 10a. This is because when air is introduced into the primary chamber 10a, air may be mixed into the dialysis fluid in the primary chamber 10a, generating air bubbles. In this case, for example, an ultrasonic sensor is provided in the primary chamber 10a, and the ultrasonic sensor detects a voltage corresponding to the vibration of the dialysis fluid. Because air bubbles have a higher attenuation rate than the dialysis fluid, the generation of air bubbles can be detected by determining whether the voltage value exceeds a predetermined threshold. The detected voltage value is transmitted to the control device 12. The control device 12 determines whether the voltage value exceeds the predetermined threshold.

[0062] Alternatively, the above determination may be made by measuring the temperature of the air introduced from the primary air introduction part 7 and the temperature of the flow path of the dialysate introduction circuit 3a (from the primary air introduction part 7 to the dialysate filter 10), and determining whether the temperature of the dialysate introduction circuit 3a is within a predetermined range based on the temperature of the introduced air. This is because when a predetermined amount of air is introduced into the dialysate filter 10, the temperature of the flow path approaches the temperature of the introduced air. In this case, for example, a thermometer is provided at the inlet of the primary air introduction part 7, and the thermometer detects the temperature of the air introduced from the primary air introduction part 7. A thermometer is also provided in the flow path between the primary air introduction part 7 and the dialysate filter 10, and the thermometer detects the temperature of the flow path. All of the detected temperature values ​​are transmitted to the control device 12. The control device 12 determines whether the temperature values ​​are within the predetermined range.

[0063] Furthermore, the above determination may be made by determining whether the dialysate flowing through the dialysate introducing circuit 3a has reached a predetermined volume (for example, the volume of the dialysate filter 10 (the primary chamber 10a and the secondary chamber 10b)). In this case, for example, a flow meter is provided in the dialysate introducing circuit 3a, and the flow meter detects the flow rate of the dialysate flowing through the dialysate introducing circuit 3a. The detected flow rate value is transmitted to the control device 12. The control device 12 determines whether the flow rate value has reached the predetermined volume.

[0064] In this embodiment, blood is returned using the dialysate in two dialysate filters (dialysate filter 10 and dialysate filter 11). For example, if the dialysate in dialysate filter 10 alone is not sufficient to return blood, the dialysate supply source is switched from dialysate filter 10 to dialysate filter 11. Note that, from a fail-safe perspective, two dialysate filters (dialysate filter 10 and dialysate filter 11) are provided in the dialysate circuit 3, and are designed so that the amount of dialysate remaining in the two dialysate filters corresponds to the amount of blood remaining in the blood circuit 2. Therefore, a desired amount of blood can be returned by introducing air into the two dialysate filters. Note that the number of dialysate filters is not limited to two. For example, the amount of dialysate remaining in one dialysate filter may be designed to correspond to the amount of blood remaining in the blood circuit 2, and similar blood return may be performed by introducing air into only one dialysate filter.

[0065] As described above, in the first embodiment, a backfiltration-type blood return process (forward fluid flow) is performed using the dialysate in dialysate filters 10 and 11. In the blood purification device described in Patent Document 1, the introduction of air into the filter through the air inlet line does not cause the dialysate to flow into the blood circuit, and the dialysate in the filter is drawn into the blood circuit by driving the blood pump. Therefore, in the blood purification device described in Patent Document 1, it is necessary to drive the blood pump.

[0066] Furthermore, in the blood purification device described in Patent Document 1, the pressure generated by the rotation of the blood pump that draws the dialysate from the blood circuit can cause negative pressure in the circuit section on the inlet side of the blood pump. When negative pressure occurs in the blood circuit, blood cell components in the blood inside the circuit can burst (hemolysis) and / or the discharge accuracy of the blood pump can deteriorate.

[0067] In the configuration according to the first embodiment, the dialysate in the dialysate filter 10 flows into the dialysate circuit 3 and the blood circuit 2 by driving the air pump 7a, so there is no need to drive the blood pump 5 to draw the dialysate. Furthermore, in the configuration according to the first embodiment, no pressure for drawing the dialysate is generated in the blood circuit 2, and the blood circuit 2 does not become negative pressure. The same applies when the dialysate in the dialysate filter 11 is used. Therefore, according to the configuration according to the first embodiment, even when the production and supply of dialysate by the dialysate supply unit 6 stops, blood can be returned more effectively than in the prior art.

[0068] In the configuration according to the first embodiment, only the control device 12, on-off valves 7c, V3, V4, V2, and air pump 7a operate. Therefore, even if the power supply from the main power source to the blood purification device 100 is stopped, blood return can be performed by supplying power from the backup power source 13 to the minimum number of components.

[0069] The blood pump 5 may also be driven by supplying power from the backup power supply 13. In this case, the blood pump 5 rotates forward to generate a forward flow of blood and dialysate in the blood circuit 2. That is, pressure for drawing dialysate is generated in the blood circuit 2. To prevent the blood circuit 2 from becoming negative pressure, the pressure in the dialysate circuit 3, which is generated by introducing air into the dialysate filter 10 (or the dialysate filter 11), is controlled so as not to exceed a predetermined threshold. This threshold may be an experimentally obtained value that prevents the blood circuit 2 from becoming negative pressure (or prevents hemolysis of the blood in the blood circuit 2). Alternatively, the pressure in the dialysate circuit 3, which is generated by introducing air into the dialysate filter 10 (or the dialysate filter 11), may be controlled so as to be higher than the pressure in the blood circuit 2 generated by driving the blood pump 5.

[0070] The above control may be performed, for example, by controlling the air pump 7a and the blood pump 5 to rotate at a predetermined number of revolutions per unit time (e.g., the air pump 7a rotates at a higher number of revolutions per unit time than the blood pump 5) so that the pressure in the dialysate circuit 3 does not exceed a threshold value (or becomes higher than the pressure in the blood circuit 2). The predetermined number of revolutions may be a value obtained experimentally. In this case, an encoder detects the number of revolutions of the air pump 7a and the blood pump 5. The detected number of revolutions is transmitted to the control device 12. The control device 12 controls the air pump 7a and the blood pump 5 to rotate at the predetermined number of revolutions based on the detected number of revolutions.

[0071] Similarly, the above control may be performed, for example, by controlling the air pump 8a and the blood pump 5 to rotate at a predetermined number of revolutions per unit time (e.g., the air pump 8a rotates at a higher number of revolutions per unit time than the blood pump 5) so that the pressure in the dialysate circuit 3 does not exceed a threshold value (or becomes higher than the pressure in the blood circuit 2). In this case, an encoder detects the number of revolutions of the air pump 8a and the number of revolutions of the blood pump 5. The detected number of revolutions is transmitted to the control device 12. The control device 12 controls the air pump 8a and the blood pump 5 to rotate at a predetermined number of revolutions based on the detected number of revolutions.

[0072] Alternatively, the above control may be performed by controlling the number of revolutions per unit time of the air pump 7a (or the number of revolutions per unit time of the air pump 8a) and the number of revolutions per unit time of the blood pump 5 based on the pressure in the dialysate circuit 3 and the pressure in the blood circuit 2. In this case, a pressure gauge is provided in the dialysate circuit 3 and detects the pressure in the dialysate circuit 3. A pressure gauge is also provided in the blood circuit 2 and detects the pressure in the blood circuit 2. Both of the detected pressure values ​​are transmitted to the control device 12. Based on the detected pressure values, the control device 12 controls both to increase the number of revolutions per unit time of the air pump 7a (or the number of revolutions per unit time of the air pump 8a) and / or to decrease the number of revolutions per unit time of the blood pump 5.

[0073] 3 and 4, a second backfiltration blood return process (reverse fluid flow) may be performed in which blood is returned to the body in the reverse fluid flow direction during the backfiltration blood return process. Fig. 5 shows the flow of dialysate when the backfiltration blood return process (reverse fluid flow) is performed using the dialysate in the dialysate filter 10.

[0074] As shown in FIG. 5, in the backfiltration-type blood return process (reverse flow), on-off valves 7c, V3, V4, and V1 are opened. Air pump 7a rotates forward. Blood pump 5 rotates reversely. The opening of these on-off valves, the rotation of air pump 7a, and the rotation of blood pump 5 are controlled by instructions from controller 12. In particular, controller 12 controls the number of revolutions per unit time of air pump 8a (controls the air flow rate of secondary air introduction part 8) so that dialysate flows into dialysate circuit 3 (dialysate introduction circuit 3a) and blood circuit 2.

[0075] By driving the air pump 7a and opening the on-off valve 7c, air is introduced into the dialysate filter 10, and the primary chamber 10a of the dialysate filter 10 becomes positive pressure. As a result, the dialysate in the primary chamber 10a reaches the secondary chamber 10b and flows through the dialysate introducing circuit 3a. In other words, the control device 12 controls the dialysate circuit 3 and the blood circuit 2 so that the dialysate flows through the flow paths shown in FIG. 5.

[0076] By opening on-off valves V3, V4, and V1, the dialysate passes through the dialysate introducing circuit 3a, the blood purifier 1 (blood purification membrane), and the blood removal circuit 2a. In Figure 5, this flow of the dialysate is indicated by thick chain arrows. Inside the blood purifier 1, the dialysate flows through the dialysate flow path, the blood purification membrane, and the blood flow path in that order. This flow of the dialysate pushes out blood remaining in the blood purifier 1 and the blood circuit 2 (blood removal circuit 2a), and the blood is returned to the body.

[0077] 5 is performed by power supplied from backup power supply 13, with at least control device 12, on-off valve 7c, on-off valve V3, on-off valve V4, on-off valve V1, air pump 7a, and blood pump 5 operating. On the other hand, components for causing dialysate to flow through dialysate circuit 3 during dialysis treatment, such as duplex pump 9, may be stopped.

[0078] When the dialysate in dialysate filter 10 flows, the dialysate supply source switches from dialysate filter 10 to dialysate filter 11. The switching of the dialysate supply source has been explained in Figures 3 and 4, so a detailed explanation will be omitted. When the dialysate supply source switches from dialysate filter 10 to dialysate filter 11, a backfiltration type blood return process (reverse fluid supply) is performed using the dialysate in dialysate filter 11.

[0079] In the backfiltration blood return process (reverse fluid transfer), the blood pump 5 is driven, and therefore the air pump 7a (or air pump 8a) and the blood pump 5 are controlled so that the pressure in the dialysate circuit 3 is higher than the pressure in the blood circuit 2. This control has been explained in Figures 3 and 4, and therefore a detailed explanation will be omitted.

[0080] Both the backfiltration blood return process (forward fluid feed direction) and the backfiltration blood return process (reverse fluid feed direction) may be performed. For example, the backfiltration blood return process (forward fluid feed direction) may be performed first using the dialysate in the dialysate filter 10, and when the dialysate supply source is switched, the backfiltration blood return process (reverse fluid feed direction) may be performed using the dialysate in the dialysate filter 11. Alternatively, the backfiltration blood return process (reverse fluid feed direction) may be performed first using the dialysate in the dialysate filter 10, and when the dialysate supply source is switched, the backfiltration blood return process (forward fluid feed direction) may be performed using the dialysate in the dialysate filter 11. By performing both the backfiltration blood return process (forward fluid feed direction) and the backfiltration blood return process (reverse fluid feed direction), blood remaining in both the blood removal side circuit 2a and the blood return side circuit 2b can be returned to the body.

[0081] <Second embodiment> 6 is a block diagram showing the configuration of a blood purification apparatus 200 according to the second embodiment. The blood purification apparatus 200 is different from the blood purification apparatus 100 according to the first embodiment in the configuration of the fluid replacement circuit 4, but the other configurations are similar. The fluid replacement circuit 4 of the blood purification apparatus 100 is a flow path from the dialysate port P to the blood removal side circuit 2a, while the fluid replacement circuit 4 of the blood purification apparatus 200 includes a blood removal side fluid replacement circuit 4a and a blood return side fluid replacement circuit 4b. The blood removal side fluid replacement circuit 4a corresponds to the fluid replacement circuit 4 of the blood purification apparatus 100.

[0082] The blood return fluid circuit 4b is a flow path from the dialysate port P to the blood return circuit 2b for returning blood in the blood circuit 2 to the body by a fluid replacement type blood return process (reverse fluid supply) described below. The blood return fluid circuit 4b is provided with an on-off valve (solenoid valve) V11. The flow of dialysate to the blood return circuit 2b is controlled by opening and closing the on-off valve V11.

[0083] Next, processing according to a second embodiment will be described with reference to Figures 7 and 8. In the second embodiment, only an example will be described in which the dialysate in the dialysate filter 10 is used to return blood remaining in the blood purifier 1 and the blood circuit 2 to the body. However, in the second embodiment, as in the first embodiment, the dialysate in the dialysate filter 11 may also be used. In other words, when the dialysate in the dialysate filter 10 flows, the dialysate supply source switches from the dialysate filter 10 to the dialysate filter 11. In the blood purification device 200, only some of the components described below function with power supplied from the backup power supply 13.

[0084] In the second embodiment, a blood return method is used in which the dialysate is introduced into the blood circuit 2 via the fluid replacement circuit 4, and the dialysate pushes out the blood in the blood circuit 2, thereby returning the blood to the body. Hereinafter, this blood return method will be referred to as a fluid replacement type blood return process. In the fluid replacement type blood return process, the dialysate flows through the dialysate circuit 3, and then passes from the dialysate circuit 3 through the fluid replacement circuit 4 and the blood circuit 2. This flow of the dialysate causes the dialysate to flow through the blood flow path of the blood purifier 1, pushing out the blood remaining in the blood circuit 2 and the blood purifier 1, and returning the blood to the body.

[0085] Figure 7 shows the flow of dialysate when a fluid replacement type blood return process is performed using the dialysate in the dialysate filter 10. In the example shown in Figure 7, blood is returned to the body in the forward fluid return process. The on-off valves shown in the figure are shown shaded, and when the on-off valves are closed, they are shown as white.

[0086] As shown in FIG. 7, in the fluid replacement type blood return process (forward fluid supply), on-off valve 7c, on-off valve V3, on-off valve V5, and on-off valve V2 are opened. Air pump 7a rotates forward. Blood pump 5 also rotates forward. The opening of these on-off valves, the rotation of air pump 7a, and the rotation of blood pump 5 are controlled by instructions from control device 12. In particular, control device 12 controls the number of revolutions per unit time of air pump 7a (controls the flow rate of air from primary air introduction part 7) so that dialysate flows through dialysate circuit 3 (dialysate introduction circuit 3a), fluid replacement circuit 4, and blood circuit 2.

[0087] By driving the air pump 7a and opening the on-off valve 7c, air is introduced into the dialysate filter 10, and the primary chamber 10a of the dialysate filter 10 becomes positive pressure. As a result, the dialysate in the primary chamber 10a reaches the secondary chamber 10b and flows through the dialysate introducing circuit 3a. In other words, the control device 12 controls the dialysate circuit 3, the replacement fluid circuit 4, and the blood circuit 2 so that the dialysate flows through the flow paths shown in Figure 7.

[0088] By opening the on-off valves V3, V5, and V2, the dialysate passes through the dialysate introduction circuit 3a, the blood removal fluid replacement circuit 4a, the blood removal circuit 2a, the blood purifier 1 (blood flow path), and the blood return circuit 2b. In Figure 7, this flow of the dialysate is indicated by thick chain arrows. This flow of the dialysate pushes out the blood remaining in the blood purifier 1 and the blood circuit 2 (blood return circuit 2b), and the blood is returned to the body.

[0089] 7 is performed by operating at least the control device 12, on-off valve 7c, on-off valve V3, on-off valve V5, on-off valve V2, air pump 7a, and blood pump 5 using power supplied from backup power supply 13. On the other hand, components such as duplex pump 9 that are used to circulate dialysate through dialysate circuit 3 and blood through blood circuit 2 during dialysis treatment may be stopped.

[0090] When the dialysate in the dialysate filter 10 flows, the dialysate supply source switches from the dialysate filter 10 to the dialysate filter 11. The switching of the dialysate supply source has been explained in the first embodiment, so a detailed explanation will be omitted. When the dialysate supply source switches from the dialysate filter 10 to the dialysate filter 11, the dialysate in the dialysate filter 11 is used to perform a fluid replacement type blood return process (forward fluid flow).

[0091] As described above, in the second embodiment, the fluid replacement type blood return process (forward fluid flow) is performed using the dialysate in the dialysate filter 10. Even in the configuration according to the second embodiment, no pressure for drawing out the dialysate is generated in the blood circuit 2, and the blood circuit 2 does not become negative pressure. The same applies when the dialysate in the dialysate filter 11 is used. Therefore, according to the configuration according to the second embodiment, blood return can be performed more satisfactorily compared to the prior art, even when the production and supply of dialysate by the dialysate supply unit 6 is stopped.

[0092] Furthermore, in the configuration according to the second embodiment, only the control device 12, on-off valve 7c, on-off valve V3, on-off valve V5, on-off valve V2, air pump 7a, and blood pump 5 operate. Therefore, even if the power supply from the main power source to the blood purification device 100 is stopped, blood return can be performed by supplying power from the backup power source 13 to the minimum number of components.

[0093] In the fluid replacement type blood return process (forward fluid flow), the dialysate passes through the blood pump 5, so the blood pump 5 needs to be driven. Therefore, pressure for drawing the dialysate is generated in the blood circuit 2. To prevent the blood circuit 2 from becoming negative pressure, the air pump 7a (or the air pump 8a) and / or the blood pump 5 is controlled so that the pressure in the dialysate circuit 3, which is generated by the introduction of air into the dialysate filter 10 (or the dialysate filter 11), does not exceed a predetermined threshold (or is higher than the pressure in the blood circuit 2 generated by the driving of the blood pump 5). This control has been described in the first embodiment, so a detailed description will be omitted.

[0094] Instead of or in addition to the blood return process described in Fig. 7, a fluid replacement type blood return process (reverse fluid supply direction) in which blood is returned to the body in the reverse fluid supply direction may be performed in the fluid replacement type blood return process. Fig. 8 shows the flow of dialysate when the fluid replacement type blood return process (reverse fluid supply direction) is performed using the dialysate in the dialysate filter 10.

[0095] As shown in FIG. 8, in the fluid replacement type blood return process (reverse fluid transfer), on-off valves 7c, V3, V11, and V1 are opened. Air pump 7a rotates forward. Blood pump 5 rotates reversely. The opening of these on-off valves, the rotation of air pump 7a, and the rotation of blood pump 5 are controlled by instructions from controller 12. In particular, controller 12 controls the number of revolutions per unit time of air pump 7a (controls the flow rate of air from primary air introduction part 7) so that dialysate flows through dialysate circuit 3 (dialysate introduction circuit 3a), fluid replacement circuit 4, and blood circuit 2.

[0096] By driving the air pump 7a and opening the on-off valve 7c, air is introduced into the dialysate filter 10, and the primary chamber 10a of the dialysate filter 10 becomes positive pressure. As a result, the dialysate in the primary chamber 10a reaches the secondary chamber 10b and flows through the dialysate introducing circuit 3a. In other words, the control device 12 controls the dialysate circuit 3, the replacement fluid circuit 4, and the blood circuit 2 so that the dialysate flows through the flow paths shown in FIG. 8.

[0097] By opening the on-off valves V3, V11, and V1, the dialysate passes through the dialysate introduction circuit 3a, the blood return fluid replacement circuit 4b, the blood return circuit 2b, the blood purifier 1 (blood flow path), and the blood removal circuit 2a. In Figure 8, this flow of the dialysate is indicated by thick chain arrows. This flow of the dialysate pushes out blood remaining in the blood purifier 1 and the blood circuit 2 (blood removal circuit 2a), and the blood is returned to the body.

[0098] 8 is performed by power supplied from backup power supply 13, with at least control device 12, on-off valve 7c, on-off valve V3, on-off valve V7, on-off valve V1, air pump 7a, and blood pump 5 operating. On the other hand, components for causing dialysate to flow through dialysate circuit 3 during dialysis treatment, such as duplex pump 9, may be stopped.

[0099] When the dialysate in the dialysate filter 10 flows, the dialysate supply source switches from the dialysate filter 10 to the dialysate filter 11. The switching of the dialysate supply source has been explained in the first embodiment, so a detailed explanation will be omitted. When the dialysate supply source switches from the dialysate filter 10 to the dialysate filter 11, a fluid replacement type blood return process (fluid return in the reverse direction) is performed using the dialysate in the dialysate filter 11.

[0100] In the fluid replacement type blood return process (reverse fluid supply), the dialysate passes through the blood pump 5, so the blood pump 5 needs to be driven. Therefore, pressure for drawing out the dialysate is generated in the blood circuit 2. To prevent the blood circuit 2 from becoming negative pressure, the air pump 7a (or the air pump 8a) and / or the blood pump 5 is controlled so that the pressure in the dialysate circuit 3 does not exceed a predetermined threshold (or becomes higher than the pressure in the blood circuit 2). This control has been described in the first embodiment, so a detailed description will be omitted.

[0101] Both the fluid replacement type blood return process (forward fluid supply direction) and the fluid replacement type blood return process (reverse fluid supply direction) may be performed. For example, the fluid replacement type blood return process (forward fluid supply direction) may be performed first using the dialysate in the dialysate filter 10, and when the dialysate supply source is switched, the fluid replacement type blood return process (reverse fluid supply direction) may be performed using the dialysate in the dialysate filter 11. Alternatively, the fluid replacement type blood return process (reverse fluid supply direction) may be performed first using the dialysate in the dialysate filter 10, and when the dialysate supply source is switched, the fluid replacement type blood return process (forward fluid supply direction) may be performed using the dialysate in the dialysate filter 11. By performing both the fluid replacement type blood return process (forward fluid supply direction) and the fluid replacement type blood return process (reverse fluid supply direction), blood remaining in both the blood removal side circuit 2a and the blood return side circuit 2b can be returned to the body.

[0102] <Third embodiment> 9 is a block diagram showing the configuration of a blood purification apparatus 300 according to the third embodiment. The blood purification apparatus 300 differs from the blood purification apparatus 100 according to the first embodiment in the configuration of the air introduction section (primary air introduction section 7 and secondary air introduction section 8), but the rest of the configuration is similar. The blood purification apparatus 300 includes an air introduction section 14 instead of the primary air introduction section 7 and secondary air introduction section 8.

[0103] Air introduction unit 14 plays the same role as primary air introduction unit 7 and secondary air introduction unit 8, and introduces air into dialysate filter 10 and dialysate filter 11. Air introduction unit 14 includes air pump 14a, air introduction path 14b, on-off valve (solenoid valve) 14c, on-off valve (solenoid valve) 14d, air filter 14e, and air filter 14f. Air pump 14a has a rotor therein and is driven to rotate. The rotor is rotated by an actuator (not shown) such as an electric motor under the control of control device 12. Air pump 14a is provided with a rotary encoder (not shown). The rotary encoder detects the rotation speed of the rotor. As air pump 14a rotates, air is introduced into dialysate filter 10 and dialysate filter 11 through air introduction path 14b.

[0104] Although not shown, the air introduction section 14 is connected to the blood removal-side air trap chamber 2c and the blood return-side air trap chamber 2d in the same manner as the primary air introduction section 7 and the secondary air introduction section 8 shown in Fig. 2. The air pump 14a also serves as a liquid level adjustment pump that adjusts the liquid levels in the blood removal-side air trap chamber 2c and the blood return-side air trap chamber 2d during dialysis treatment, for example.

[0105] Air introduced into dialysate filter 10 and dialysate filter 11 by driving air pump 14a causes dialysate to flow into dialysate circuit 3 (dialysate introduction circuit 3a) and blood circuit 2. The flow of air into dialysate filter 10 is controlled by opening and closing on-off valve 14c provided between air pump 14a and dialysate filter 10. Similarly, the flow of air into dialysate filter 11 is controlled by opening and closing on-off valve 14d provided between air pump 14a and dialysate filter 11. Air filters 14e and 14f remove dust particles from the air. Note that air filters 14e and 14f are not essential components of air introduction section 14.

[0106] In the third embodiment, compared to the first and second embodiments, for example, instead of including two air pumps, 7a and 8a, only air pump 14a is included. Similarly, instead of including two air introduction paths, 7b and 8b, only air introduction path 14b is included. In this way, the configuration of the entire device is further simplified.

[0107] Next, processing according to a third embodiment will be described with reference to Figures 10 and 11. In the third embodiment, only an example will be described in which blood remaining in the blood purifier 1 and the blood circuit 2 is returned to the body by a backfiltration-type blood return process (forward fluid flow) using the dialysate filters 10 and 11. However, even in the third embodiment, blood may be returned by any of a backfiltration-type blood return process (reverse fluid flow), a fluid replacement-type blood return process (forward fluid flow), and a fluid replacement-type blood return process (reverse fluid flow). In the blood purification device 300, only some of the components described below function with power supplied from the backup power supply 13.

[0108] 10 shows the flow of dialysate when a backfiltration type blood return process (forward flow) is performed using the dialysate in the dialysate filter 10. The on-off valves shown in the figure are shown shaded, and when the on-off valves are closed, they are shown as outlined.

[0109] As shown in Figure 10, in the backfiltration blood return process (forward solution flow), on-off valves 14c, V3, V4, and V2 are opened. Air pump 14a rotates forward. The opening of these on-off valves and the rotation of air pump 14a are controlled by instructions from control device 12. In particular, control device 12 controls the number of revolutions per unit time of air pump 14a (controls the flow rate of air from air inlet 14) so ​​that dialysate flows into dialysate circuit 3 (dialysate introduction circuit 3a) and blood circuit 2.

[0110] By driving the air pump 14a and opening the on-off valve 14c, air is introduced into the dialysate filter 10, and the primary chamber 10a of the dialysate filter 10 becomes positive pressure. As a result, the dialysate in the primary chamber 10a reaches the secondary chamber 10b and flows through the dialysate introducing circuit 3a. In other words, the control device 12 controls the dialysate circuit 3 and the blood circuit 2 so that the dialysate flows through the flow paths shown in FIG. 10.

[0111] By opening on-off valves V3, V4, and V2, the dialysate passes through the dialysate introducing circuit 3a, the blood purifier 1 (blood purification membrane), and the blood return circuit 2b. In Figure 10, this flow of the dialysate is indicated by thick chain arrows. Inside the blood purifier 1, the dialysate flows through the dialysate flow path, the blood purification membrane, and the blood flow path in this order. This flow of the dialysate pushes out blood remaining in the blood purifier 1 and the blood circuit 2 (blood return circuit 2b), and the blood is returned to the body.

[0112] 10 is performed by operating at least the control device 12, on-off valve 14c, on-off valve V3, on-off valve V4, on-off valve V2, and air pump 14a using power supplied from backup power supply 13. On the other hand, components such as blood pump 5 and duplex pump 9, which are used to circulate dialysate through dialysate circuit 3 and blood through blood circuit 2 during dialysis treatment, may be stopped.

[0113] When the dialysate in the dialysate filter 10 flows, the dialysate supply source switches from the dialysate filter 10 to the dialysate filter 11. The switching of the dialysate supply source has been explained in the first embodiment, so a detailed explanation will be omitted. Figure 11 shows the flow of the dialysate when the backfiltration type blood return process (forward fluid flow) is performed using the dialysate in the dialysate filter 11.

[0114] As shown in Figure 11, when the dialysate supply source is switched from dialysate filter 10 to dialysate filter 11, on-off valve 14c closes. On the other hand, on-off valve 14d opens. The opening and closing of these on-off valves is controlled by instructions from control device 12. In particular, control device 12 controls the number of revolutions per unit time of air pump 14a (controls the flow rate of air from air inlet part 14) so ​​that dialysate flows into dialysate circuit 3 (dialysate introducing circuit 3a) and blood circuit 2.

[0115] By driving the air pump 14a and opening the on-off valve 14d, air is introduced into the dialysate filter 11, and the primary chamber 11a of the dialysate filter 11 becomes positive pressure. As a result, the dialysate in the primary chamber 11a reaches the secondary chamber 11b and flows through the dialysate introducing circuit 3a. The dialysate then flows through a flow path similar to that shown in FIG. 11. That is, the control device 12 controls the dialysate circuit 3 and the blood circuit 2 so that the dialysate flows through the flow path shown in FIG. 11. In FIG. 11, this flow of the dialysate is indicated by thick chain arrows.

[0116] 11 is performed by operating at least the control device 12, on-off valve 14d, on-off valve V3, on-off valve V4, on-off valve V2, and air pump 14a using power supplied from backup power supply 13. Meanwhile, blood pump 5, duplex pump 9, and the like may be stopped.

[0117] As described above, in the third embodiment, the dialysate supply source is switched by the single air introduction part 14. The configuration according to the third embodiment also does not require the blood pump 5 to be driven. Furthermore, the configuration according to the third embodiment also does not generate pressure for drawing dialysate in the blood circuit 2, and the blood circuit 2 does not become negative pressure. Therefore, the configuration according to the third embodiment allows for better blood return than the prior art, even when the production and supply of dialysate by the dialysate supply part 6 is stopped.

[0118] In the first to third embodiments described above, two dialysate filters (dialysate filter 10 and dialysate filter 11) are used, but a single dialysate filter or three or more dialysate filters may be used. That is, the dialysate in n (n is an integer of 1 or more) dialysate filters is used to return the blood remaining in the blood purifier 1 and the blood circuit 2 to the body. For example, when three or more dialysate filters are used, the dialysate supply source is switched in three stages according to the above-described determination method. Blood is returned using the dialysate stored in dialysate filter 10 and dialysate filter 11, but a dedicated chamber for storing the dialysate may be provided.

[0119] Furthermore, in the first to third embodiments, the primary air introduction unit 7 may be configured to include a compressed air tank containing compressed air instead of the air pump 7a. In this configuration, air is introduced from the compressed air tank through the air introduction path 7b into the dialysate filter 10 by opening the on-off valve 7c. Similarly, the secondary air introduction unit 8 and the air introduction unit 14 may be configured to include a compressed air tank instead of the air pump 8a and the air pump 14a. In addition to the above, the rotation of the air pump 7a, the air pump 8a, the air pump 14a, and the blood pump 5 is controlled using a rotary encoder, but may be controlled in other ways. The rotation of the air pump 7a, the air pump 8a, the air pump 14a, and the blood pump 5 may be controlled based on open-loop control using, for example, a pulse motor.

[0120] Furthermore, any combination of the backfiltration type blood return process (forward and reverse fluid delivery directions) and the fluid replacement type blood return process (forward and reverse fluid delivery directions) may be performed. For example, the fluid replacement type blood return process (forward fluid delivery direction) may be performed first using the dialysate in the dialysate filter 10, and then, when the dialysate supply source is switched, the backfiltration type blood return process (reverse fluid delivery direction) may be performed using the dialysate in the dialysate filter 11.

[0121] Furthermore, although the first to third embodiments described above are primarily applied to the blood return process, the present invention is not limited to such an example. The above-described processing may also be applied to a fluid replacement process for preventing a drop in blood pressure caused by a reduction in the patient's blood volume due to a water removal process that removes excess water from the blood. In the fluid replacement process, a dialysis fluid is injected into the blood circuit to replenish the blood in the body.

[0122] The above-described embodiments are merely examples, and the scope of the embodiments is not limited to the described examples. In addition to the described processes and components, additional processes and / or components may be added. Also, changes may be made to the described processes and / or components, or certain processes and / or components may be omitted, without departing from the concept of the invention. Furthermore, the order of the described processes may be changed.

[0123] The blood purification apparatus according to the embodiment is implemented by a computer program executed by the control device 12, and the computer program may be stored in a non-transitory storage medium. Examples of non-transitory storage media include read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disk devices, magneto-optical media, and optical media such as CD-ROM disks and digital versatile disks (DVDs). [Explanation of symbols]

[0124] 1. Blood Purifier 1a Blood inlet 1b Blood outlet 1c Dialysate inlet 1d Dialysate outlet 2 Blood circuit 2a Blood removal circuit 2b Blood return circuit 2c Air trap chamber on the blood removal side 2d Blood return side air trap chamber 3 Dialysate circuit 3a Dialysis fluid introduction circuit 3b Dialysate drain circuit 4 Fluid replacement circuit 4a Blood removal side fluid replacement circuit 4b Blood return side fluid replacement circuit 5. Blood Pump 6 Dialysis fluid supply unit 7 Primary air intake 7a Air pump 7b Air intake passage 7c On-off valve 7d Air filter 7e Air Filter 8 Secondary air intake 8a Air pump 8b Air intake passage 8c On-off valve 8d Air filter 8e Air Filter 9. Duplex Pump 10 Dialysis fluid filter 10a Primary Chamber 10b Secondary chamber 11 Dialysis fluid filter 11a Primary chamber 11b Secondary chamber 12 Control device 13 Backup power supply 14 Air intake section 14a Air pump 14b Air intake passage 14c On-off valve 14d On-off valve 14e Air Filter 14f Air Filter 100 Blood Purification Device 200 Blood Purification Device 300 Blood Purification Device P Dialysis fluid port V1~V11 on-off valves

Claims

1. a blood circuit and a dialysate circuit connected via a blood purifier; a chamber provided in the blood circuit for storing blood in the blood circuit; an air introduction channel connected to the dialysis fluid circuit; an air introduction unit that is provided in the dialysate circuit or the air introduction path and that introduces air into the dialysate circuit via the air introduction path to create a positive pressure in the dialysate circuit, the air introduction unit being connected to the chamber and flowing air into the chamber to adjust the liquid level in the chamber; a control device that controls the air introducing part so that the dialysate flows from the dialysate circuit to the blood circuit, and controls the pressure in the blood circuit and the dialysate circuit so that the blood in the blood circuit and the blood purifier is returned to the body by causing the dialysate to flow from the dialysate circuit to the blood circuit; Equipped with the control device controls the air introducing unit to introduce air into the dialysate circuit without allowing air to flow through the chamber when returning the blood in the blood circuit and the blood purifier to the body. A blood purification device characterized by:

2. a dialysate filter provided in the dialysate circuit to purify and store the dialysate flowing through the dialysate circuit; Furthermore, the air introduction section introduces air into the dialysate filter to push the dialysate stored in the dialysate filter into the dialysate circuit.

2. The blood purification device according to claim 1.

3. the dialysate filter includes at least a first dialysate filter and a second dialysate filter; When the control device determines that the dialysate stored in the first dialysate filter has been pushed out into the dialysate circuit, the control device controls the air introducing unit to introduce air into the second dialysate filter.

3. The blood purification apparatus according to claim 2.

4. a first on-off valve provided between the air introduction part and the first dialysate filter; a second on-off valve provided between the air introduction part and the second dialysate filter; Furthermore, When the control device determines that the dialysis fluid stored in the first dialysis fluid filter has been pushed out into the dialysis fluid circuit, the control device controls the first on-off valve to close and the second on-off valve to open.

4. The blood purification apparatus according to claim 3.

5. 5. The blood purification device according to claim 1, wherein the control device controls the dialysate circuit and the blood circuit so that the dialysate flows from the dialysate circuit through the blood purifier and into the blood circuit.

6. The blood circuit includes a blood return side circuit, 6. The blood purification apparatus according to claim 5, wherein the control device controls the dialysate circuit and the blood circuit so that the dialysate flows from the dialysate circuit through the blood purifier and into the blood return side circuit.

7. the blood circuit includes a blood removal side circuit, the control device controls the dialysate circuit and the blood circuit so that the dialysate flows from the dialysate circuit through the blood purifier and into the blood removal side circuit.

6. The blood purification apparatus according to claim 5.

8. 8. The blood purification apparatus according to claim 1, wherein the control device controls the flow rate of air from the air inlet so that the dialysate flows from the dialysate circuit to the blood circuit.

9. a blood pump that drives the blood circuit to pump the liquid therethrough; Furthermore, the control device controls the flow rate of air from the air introduction part while controlling the blood pump so as not to drive the blood pump, thereby causing the dialysate to flow from the dialysate circuit to the blood circuit.

9. The blood purification apparatus according to claim 1, wherein the blood purification system is a blood purification system.

10. 9. The blood purification apparatus according to claim 8, wherein the control device controls the air introducing part so that pressure in the dialysate circuit, which is generated by introducing the air into the dialysate circuit, does not exceed a predetermined threshold.

11. a blood pump that drives the blood circuit to pump the liquid therethrough; Furthermore, controlling the air introduction section and / or the blood pump so that the pressure in the dialysis fluid circuit downstream of the junction with the air introduction channel is higher than the pressure in the blood circuit generated by driving the blood pump; 9. The blood purification apparatus according to claim 1, wherein the blood purification system is a blood purification system.

12. the air introduction path includes a first air introduction path connected to the dialysate circuit and a second air introduction path connected to the dialysate circuit at a location different from the first air introduction path; the air introduction section includes a single pump; the single pump is shared between a case where the air introduction unit introduces air via the first air introduction path and a case where the air introduction unit introduces air via the second air introduction path; 12. The blood purification apparatus according to claim 1.

13. a blood purification device including a blood circuit and a dialysate circuit connected via a blood purifier; a chamber provided in the blood circuit and accommodating blood in the blood circuit; an air introduction channel connected to the dialysate circuit; an air introduction unit provided in the dialysate circuit or the air introduction channel and introducing air into the dialysate circuit via the air introduction channel to create a positive pressure in the dialysate circuit, the air introduction unit being connected to the chamber and adjusting the liquid level in the chamber by flowing air into the chamber; and a control device for controlling the pressure in the blood circuit and the dialysate circuit, wherein the blood circuit has a blood removal side circuit which is a flow path for introducing the blood into the blood purifier, and a blood return side circuit which draws the blood from the blood purifier; The control device controlling the air introducing section to cause the dialysate to flow from the dialysate circuit to the blood return circuit; controlling the blood circuit and the dialysate circuit so that the dialysate flows from the dialysate circuit to the blood return circuit, thereby directing blood from the blood removal circuit and the blood purifier to the blood return circuit; controlling the air introducing unit so as to introduce air into the dialysate circuit without flowing air through the chamber when the blood in the blood removal side circuit and the blood purifier is led to the blood return side circuit; A method for operating a blood purification device, comprising:

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