Blood purification device and blood purification circuit

Abstract

The present invention comprises an artery clamp that is capable of opening and closing an artery-side blood circuit, a vein clamp that is capable of opening and closing a vein-side blood circuit, a pump that is capable of introducing or discharging air into or from a gas circuit, and a processing unit that controls the pump, the artery clamp, and the vein clamp, wherein the processing unit comprises: a pump control unit that controls the rotation direction of the pump to alternately perform introduction of gas into a branch part and discharge of gas from the branch part and thereby alternately perform a blood removal process and a blood return process on a patient; and a clamp control unit that performs control such that, during the blood removal process, a flow path of the vein-side blood circuit is closed by the vein clamp while a flow path of the artery-side blood circuit is opened by the artery clamp, and, during the blood return process, the flow path of the vein-side blood circuit is opened by the vein clamp while the flow path of the artery-side blood circuit is closed by the artery clamp.

Description

Blood purification device and blood purification circuit

[0001] The present disclosure relates to a blood purification device that performs blood purification therapy while extracorporeally circulating a patient's blood, and a blood purification circuit used therein.

[0002] Dialysis treatment using a blood purification device having a dialyzer and a blood circuit has been known as an example of blood purification treatment. In this dialysis treatment, blood taken from a patient is circulated extracorporeally through a blood circuit, purified using a dialyzer connected to the blood circuit, and the purified blood is returned to the patient. Traditionally, patients requiring dialysis treatment were adults with impaired renal function, but in recent years, newborns and children have also become eligible for dialysis treatment.

[0003] In this blood purification, to ensure patient safety, the amount of blood that can be removed from the body at one time is determined based on the patient's weight, etc. For this reason, for adults who are relatively heavy, the blood flow rate is generally set to approximately 200 ml / min. On the other hand, for newborns and children who are much lighter than adults, the blood flow rate must be set to 100 ml / min or less, although this depends on their weight. Even for adults, a low blood flow rate of 100 ml / min or less may be set depending on the patient's condition.

[0004] To enable such blood purification treatment according to body weight, for example, Patent Document 1 discloses calculating the blood flow rate based on the patient's input weight. Furthermore, to enable blood purification treatment with the above-mentioned low flow rate, for example, Patent Document 2 discloses using a pediatric tube with a smaller inner diameter than tubing used for adult treatment. Furthermore, Patent Document 3 discloses a pediatric blood purification column for blood volumes of 10 ml or less.

[0005] JP 2023-119259 A Japanese Patent No. 5525874 A Japanese Patent No. 5870920 A

[0006] However, simply reducing the size of each component of the blood purification device was not enough to sufficiently reduce the amount of extracorporeally circulating blood due to the presence of other components of the blood purification device. Furthermore, in blood purification devices using a blood pump such as those disclosed in Patent Documents 1 and 3, the pressure fluctuations in the extracorporeal circulation section were large, making it impossible to achieve blood purification with reduced cardiopulmonary burden for newborns, children, and adults who require a low blood volume.

[0007] The present disclosure has been made in consideration of these problems, and its purpose is to provide a blood purification device and a blood purification circuit that can control pressure fluctuations in the extracorporeal circulation section while reducing the amount of blood circulating extracorporeally.

[0008] According to one aspect of the present disclosure, a blood purification device includes: a blood purifier for purifying a patient's blood; an arterial blood circuit serving as a blood flow path for introducing the blood removed from the patient into the blood purifier; a venous blood circuit serving as a blood flow path from the blood purifier to the patient; and a gas circuit connected to a branching portion that branches off either the arterial blood circuit or the venous blood circuit and serving as an air flow path, the blood purification device including: an arterial clamp to which the arterial blood circuit can be attached and capable of opening and closing the blood flow path of the arterial blood circuit; a venous clamp to which the venous blood circuit can be attached and capable of opening and closing the blood flow path of the venous blood circuit; a pump capable of introducing or evacuating air to or from the gas circuit; and a valve for connecting the pump, the arterial clamp, and the venous clamp to which the venous blood circuit can be attached and capable of opening and closing the blood flow path of the venous blood circuit. a pump controller that controls a rotation direction of the pump and alternately introduces the gas into the branching portion and discharges the gas from the branching portion, thereby alternately performing a blood removal process and a blood return process for the patient, and a clamp controller that controls the arterial clamp to open the flow path of the arterial blood circuit while the venous clamp closes the flow path of the venous blood circuit during the blood removal process, and controls the arterial clamp to close the flow path of the arterial blood circuit while the venous clamp opens the flow path of the venous blood circuit during the blood return process.

[0009] According to one aspect of the present disclosure, there is provided "a blood purification circuit connected to a blood purifier that purifies a patient's blood, comprising: an arterial blood circuit that serves as a blood flow path for introducing the blood removed from the patient into the blood purifier; a venous blood circuit that serves as a blood flow path from the blood purifier to the patient; a gas circuit that serves as an air flow path and is connected to a branching point that branches off either the arterial blood circuit or the venous blood circuit; a pump connected only to the gas circuit among the arterial blood circuit, the venous blood circuit, and the gas circuit, and in which blood removal and return processes of the blood are alternately performed depending on the operating state of the pump."

[0010] According to the present disclosure, it is possible to provide a blood purification device and a blood purification circuit that are capable of controlling pressure fluctuations in the extracorporeal circulation section while reducing the amount of blood circulating extracorporeally.

[0011] It should be noted that the above effects are merely examples for the sake of convenience of explanation, and the effects of the present disclosure are not limited to these. In addition to the above effects, the present disclosure can achieve any of the effects described herein.

[0012] FIG. 1 is a schematic diagram showing an example of the usage state of the blood purification apparatus according to the first embodiment. FIG. 2 is a block diagram showing the electrical configuration of the blood purification apparatus according to the first embodiment. FIG. 3 is a configuration diagram of the extracorporeal circulation unit of the blood purification apparatus according to the first embodiment. FIG. 4 is a functional block diagram of the blood purification apparatus according to the first embodiment. FIG. 5 is a flowchart showing the flow of treatment in the blood purification apparatus according to the first embodiment. FIG. 6 is a schematic diagram showing the drive pattern during blood purification treatment in the blood purification apparatus according to the first embodiment. FIG. 7 is a configuration diagram of the extracorporeal circulation unit of the blood purification apparatus according to the first embodiment when blood is removed. FIG. 8 is a configuration diagram of the extracorporeal circulation unit of the blood purification apparatus according to the first embodiment when blood is returned. FIG. 9 is a flowchart showing the flow of correction in the blood purification apparatus according to the first embodiment. FIG. 10 is an example of conditions for blood purification treatment for newborns and children using a conventional blood purification apparatus. FIG. 11 is a configuration diagram of the extracorporeal circulation unit of a blood purification apparatus according to a modified example of the first embodiment. FIG. 12 is a configuration diagram of the extracorporeal circulation unit of the blood purification apparatus according to the second embodiment.

[0013] The blood purification device and blood purification circuit of the present disclosure will be described in detail below with reference to the drawings. The present disclosure is not limited to the content described below and can be modified as desired without departing from the spirit and scope of the present disclosure. The drawings used in each embodiment are schematic illustrations of the blood purification device of the present disclosure, and may include partial emphasis, enlargement, reduction, or omission to facilitate understanding. Therefore, the scale and shape of each component may not be accurately represented. Furthermore, some numerical values ​​used in each embodiment are merely examples and can be modified as necessary. The same reference symbols are used to designate components that are common to all drawings.

[0014] First Embodiment (Configuration of Blood Purification Apparatus) First, the configuration of the blood purification apparatus and blood purification circuit of the present disclosure will be described with reference to Figs. 1 to 4. Fig. 1 is a schematic diagram showing an example of the usage state of the blood purification apparatus according to this embodiment. Fig. 2 is a block diagram showing the electrical configuration of the blood purification apparatus according to this embodiment. Fig. 3 is a configuration diagram of the extracorporeal circulation section of the blood purification apparatus according to this embodiment. Fig. 4 is a functional block diagram of the blood purification apparatus according to the first embodiment.

[0015] As shown in Figure 1, the blood purification device 1 is composed of a dialysis machine for performing dialysis treatment on a patient H. Specifically, the blood purification device 1 has a main body 3 installed on a base unit 2, a display 4 connected to the top of the main body 3, and a blood purifier 5 installed to the side of the main body 3. The main body 3 of the blood purification device 1 also has a processing unit 6 that processes various information and data, an internal piping unit 7 for circulating a dialysis fluid between the main body 3 and the blood purifier 5, and an extracorporeal circulation unit 8 for circulating blood, which is a bodily fluid of the patient H, outside the body.

[0016] With this configuration, the blood purification device 1 is capable of extracting blood from the patient H outside the body (blood removal process), removing unnecessary or toxic substances or water from the blood in the blood purifier 5 (blood purification process), and returning the purified blood to the patient H (blood return process). Here, the extracorporeal circulation unit 8 forms a circuit for purifying the blood, and corresponds to the blood purification circuit in this disclosure. The blood purification device 1 is composed of a device base unit 1a including the main body 3, display 4, processing unit 6, and internal piping unit 7, and a consumables unit 1b including the blood purifier 5 and extracorporeal circulation unit 8.

[0017] The base unit 2 is composed of a plate-shaped base 2a connected to the bottom of the main body 3 and four casters 2b attached to the base 2a, which allows for easy movement of the blood purification device 1. The number of casters 2b is not limited to four, and may be three or five or more as long as it allows the blood purification device 1 to be moved.

[0018] The main body 3 is composed of a roughly rectangular parallelepiped housing. Inside and on the surface of the main body 3, various components and devices that constitute the internal piping section 7 and extracorporeal circulation section 8 of the blood purification device 1 are arranged. For example, the components may include various pumps and detectors, and the components may include a blood circuit, a dialysate circuit, and various sensors.

[0019] As shown in Figure 2, the blood purification device 1 has a display 4, a processing unit 6, an internal piping unit 7, and an extracorporeal circulation unit 8 electrically connected to one another via control lines and data lines. This allows the blood purification device 1 to transmit and receive various signals, data, and information, and also enables various controls by the processing unit 6. In the following, data is basically assumed to consist of numerical values, symbols, characters, etc., resulting from processing of signals, etc. Information is basically assumed to be collected or processed data, such as data that the recipient can use for subsequent consideration or that can be utilized by the recipient. However, data and information may also be used in ways that do not conform to the above assumptions, depending on their content and context.

[0020] When treating a patient using the blood purification apparatus 1 and blood purifier 5, the process proceeds in the following order: pre-process, treatment process, and post-process. The pre-process is a predetermined preparation process carried out before the treatment process, specifically, priming, gas purging, and initial blood removal. Priming is a process of cleaning the blood circuit constituting the extracorporeal circulation unit 8 and the blood side of the blood purifier 5, removing air bubbles, and filling with a priming solution. Gas purging is a process of cleaning the dialysate side of the blood purifier 5, removing air bubbles, and filling with a solution. Furthermore, initial blood removal is a process of withdrawing blood from patient H and replacing it with the priming solution filling the blood circuit and the blood side of the blood purifier 5.

[0021] The treatment process involves the steps of drawing blood from the patient (blood removal process), purifying the patient's blood using the blood purifier 5 (blood purification process), and returning the purified blood to the patient (blood return process). In this embodiment, the blood removal process and the blood return process are performed alternately.

[0022] The post-treatment process is a process carried out after the treatment process to complete the patient's treatment, specifically, the final blood return, which is a process of returning the blood remaining in the blood purifier 5 and the blood circuit to the patient after the treatment is completed.

[0023] In this embodiment, a hemodialysis device is described as an example of the blood purification device 1, but the blood purification device 1 is not limited to this. For example, an acute blood purification device, a peritoneal dialysis device, an ultrafiltration device, or a hemofiltration device can also be an example of the blood purification device 1.

[0024] In addition to the above-described configuration, the blood purification apparatus 1 may also have a communication unit that enables transmission and reception of information to and from an external device such as a terminal device or a server device, etc. This allows the blood purification apparatus 1 to obtain various types of information related to the treatment of the patient (patient information) from the external device via the communication unit.

[0025] The blood purification device 1 of this embodiment is configured to be able to perform treatment even when the blood flow rate during blood removal and blood return is 50 ml / min or less, particularly 15 ml / min or less, and even 3 ml / min or less. Therefore, the blood purification device 1 of this embodiment can appropriately treat newborn and pediatric patients, but this is not limited to these patients. For example, even in adult patients in the early stages of renal disease, the blood flow rate may be set to 50 ml / min or less. Naturally, the blood purification device 1 of this embodiment can also perform treatment when the blood flow rate is 50 ml / min or more, and can also handle blood flow rates of 100 ml / min or more, particularly 600 ml / min or more. The reasons why this device can handle blood flow rates ranging from normal to very low will be explained later.

[0026] [Display] Next, as shown in Figures 1 and 2, the display 4 has an input section 4a consisting of a touch panel type input interface and an output section 4b consisting of a general screen type output interface. That is, the display 4 in this embodiment is a touch panel equipped with an input / output interface. Here, the input detection method by the touch panel may be any method, such as a capacitance type or a resistive film type. Furthermore, the operable area and position on the touch panel can be freely set by the administrator of the blood purification device 1, etc. That is, the arrangement of the input section 4a and output section 4b on the display 4 can be set as appropriate.

[0027] The input interface may be separated from the display 4. In this case, the blood purification apparatus 1 may be provided with an input device such as a keyboard with physical key buttons, such as a numeric keypad or character input keys, and a mouse.

[0028] 1 and 3, the blood purifier 5 has a blood inlet 5a and a blood outlet 5b as blood-side ports at both ends of its housing, and a dialysate inlet 5c and a dialysate outlet 5d as dialysate-side ports on the side of its housing. An arterial blood circuit L1 (described later) is connected to the blood inlet 5a, and a venous blood circuit L2 (described later) is connected to the blood outlet 5b. Furthermore, the dialysate inlet 5c and the dialysate outlet 5d are connected to an internal piping unit 7 via piping for circulating the dialysate.

[0029] The blood purifier 5 contains a plurality of hollow fiber membranes (not shown), which constitute a blood purification membrane for purifying blood. A blood flow path through which the blood of patient H flows via the blood purification membrane and a dialysate flow path through which the dialysate flows are formed within the blood purifier 5. The hollow fiber membranes constituting the blood purification membrane have many minute pores formed therein, penetrating from the outer circumferential surface to the inner circumferential surface, allowing impurities in the blood to permeate into the dialysate via the hollow fiber membranes.

[0030] The blood purifier 5 is not limited to a dialyzer having the above-described configuration. For example, it may be an adsorption-type blood purifier used in endotoxin adsorption therapy, activated carbon adsorption therapy, bilirubin adsorption therapy, etc. The blood purifier 5 may also be a hemodiafilter.

[0031] [Internal Piping Section] The internal piping section 7 is provided inside the main body 3 and is connected via piping to two dialysate inlets 5c and two dialysate outlets 5d provided on the side surfaces of the blood purifier 5. For example, the internal piping section 7 has various components such as piping, pumps, valves, sensors, and filters. More specifically, the internal piping section 7 may have a duplex pump, a water removal pump, a degassing pump, a pressure pump, a pressure reducing valve, an electromagnetic valve, a temperature sensor, a pressure sensor, a chemical filter, and the like. Furthermore, flexible materials such as polyvinyl chloride tubing or silicone tubing may be used for the piping.

[0032] The internal piping section 7 is assembled by appropriately selecting the above-mentioned parts according to the piping configuration and model, and has a structure that enables the circulation and cleaning of the dialysate. The internal piping section 7 also has a structure that enables the introduction and discharge of the dialysate to and from the blood purifier 5. Note that these specific configurations are not characteristic of the blood purification device of the present disclosure, and therefore a description thereof will be omitted.

[0033] 3 , the extracorporeal circulation section 8, which is a blood purification circuit, has three circuits: an arterial blood circuit L1, a venous blood circuit L2, and a gas circuit L3, as well as a branching section 23 connecting the venous blood circuit L2 and the gas circuit L3. Here, the arterial blood circuit L1 is a circuit that introduces blood drawn from a patient H into the blood purifier 5, and the venous blood circuit L2 is a circuit that returns blood purified by the blood purifier 5 to the patient H. The arterial blood circuit L1 and the venous blood circuit L2 constitute a blood circuit through which the patient's blood flows. The gas circuit L3 is a circuit that introduces gas into the branching section 23 and extracts gas from the branching section 23.

[0034] 3, one end of the arterial blood circuit L1 is connected via a Y-shaped tube 21 to a single needle 22 inserted into the arm of the patient H, and the other end is connected to the blood inlet 5a of the blood purifier 5. Here, the Y-shaped tube 21 has one end connected to the needle 22 and the other end branched into two, one of which is connected to the arterial blood circuit L1 via a connector (not shown).

[0035] The arterial blood circuit L1 is attached to an arterial clamp V1 provided on the device base 1a side of the blood purification device 1. The arterial clamp V1 is composed of an electromagnetic valve, and operates in response to a drive signal received from the processing unit 6 to open and close the flow path of the arterial blood circuit L1. The opening and closing operation of the arterial clamp V1 makes it possible to control the process of removing blood from the patient H and introducing it into the blood purifier 5.

[0036] 3, one end of the venous blood circuit L2 is connected via a Y-shaped tube 21 to a single puncture needle 22 inserted into the arm of the patient H, and the other end is connected to the blood outlet 5b of the blood purifier 5. Here, the venous blood circuit L2 is connected via a connector (not shown) to the other branched end of the Y-shaped tube 21, which is not connected to the arterial blood circuit L1.

[0037] The venous blood circuit L2 is attached to a venous clamp V2 provided on the device base 1a side of the blood purification device 1. The venous clamp V2 is composed of an electromagnetic valve, and operates in response to a drive signal received from the processing unit 6 to open and close the flow path of the venous blood circuit L2. The opening and closing operation of the venous clamp V2 makes it possible to control the blood return process for returning blood to the patient H.

[0038] Furthermore, the venous blood circuit L2 is provided with a branch 23. Specifically, the branch 23 is located between the blood purifier 5 and the venous clamp V2. The branch 23 is composed of a chamber capable of storing blood and gas. The branch 23 has a shape extending vertically. The venous blood circuit L2 extending from the blood outlet 5b of the blood purifier 5 is connected to the side of the branch 23, and the venous blood circuit L2 extending to the Y-tube 21 via the venous clamp V2 is connected to the bottom located vertically below. Furthermore, one end of the gas circuit L3 is connected to the top of the branch 23 located vertically above.

[0039] With this structure of the branching part 23, blood purified by the blood purifier 5 can be introduced from the side of the branching part 23, and the introduced blood is temporarily stored in the branching part 23. The stored blood can also be led out to the venous blood circuit L2 from the bottom of the branching part 23. Details of the lead-in and lead-out of blood at the branching part 23 will be described later.

[0040] A liquid level detector 24 is provided around the branching portion 23 to detect the level of blood stored in the branching portion 23. The liquid level detector 24 is composed of oscillation elements 24a and 24b and reception elements 24c and 24d provided on the sides of the branching portion 23. Specifically, the pair of oscillation element 24a and reception element 24c constitutes one set of sensors, and the pair of oscillation element 24b and reception element 24d constitutes another set of sensors, and these two sensors are arranged to be spaced apart in the vertical direction. In particular, the oscillation element 24a and reception element 24c are located vertically above, and the oscillation element 24b and reception element 24d are located vertically below.

[0041] With this configuration, ultrasonic waves of a predetermined wavelength are emitted from the oscillation elements 24 a and 24 b toward the reception elements 24 c and 24 d, and the presence or absence of blood is determined based on a change in the wavelength of the received ultrasonic waves, thereby detecting the blood level. In particular, when the position of the blood level changes at the branching portion 23, it is possible to detect whether the blood level has reached a predetermined height above in the vertical direction or a predetermined height below in the vertical direction.

[0042] The configuration of the liquid level detection unit 24 is not limited to the sensor consisting of the above-mentioned oscillation element and receiving element, but may also use a sensor that captures an image of the blood liquid level, a sensor that detects the liquid level by coming into contact with blood, a sensor consisting of a light-emitting element and a light-receiving element, etc.

[0043] As can be seen from Figure 3, one end of the gas circuit L3 is connected to the top of the branch portion 23, and the other end is open to the atmosphere. In addition, a pump P1 is connected to the gas circuit L3. As a result, the pump P1 is driven to rotate forward (clockwise) and reverse (counterclockwise), allowing air to be introduced into the branch portion 23 and air to be discharged from the branch portion 23. Specifically, when the pump P1 rotates forward, air is supplied to the branch portion 23, and when the pump P1 rotates reverse, air is discharged from the branch portion 23.

[0044] The rotational speed (number of rotations) of the pump P1 in the forward and reverse directions can be controlled by changing the drive signal supplied to the pump. That is, as the rotational speed of the pump P1 increases, the amount of air supplied or discharged increases, and as the rotational speed of the pump P1 decreases, the amount of air supplied or discharged decreases.

[0045] The type of pump P1 is not particularly limited as long as it can introduce air into the branch portion 23 and discharge air from the branch portion 23. In this embodiment, a peristaltic pump is assumed, but other pumps such as a diaphragm pump may also be used.

[0046] By controlling the introduction and discharge of air and the arterial clamp V1 and the venous clamp V2, blood removal and return are possible. Specifically, when the arterial clamp V1 opens the flow path of the arterial blood circuit L1, and the venous clamp V2 closes the flow path of the venous blood circuit L2, and air is discharged from the branch 23, negative pressure is generated inside the branch 23, causing a flow in which blood is drawn toward the side of the branch 23. As a result, blood is removed from the patient H and stored in the branch 23 via the blood purifier 5. On the other hand, when the arterial clamp V1 closes the flow path of the arterial blood circuit L1, and the venous clamp V2 opens the flow path of the venous blood circuit L2, and air is introduced into the branch 23, positive pressure is generated inside the branch 23, causing a flow in which blood is pushed out from the bottom of the branch 23. As a result, purified blood is returned to the patient H. That is, by controlling the rotation direction of the pump P1 and controlling the driving of the arterial clamp V1 and venous clamp V2, the blood removal process and the blood return process are alternately and repeatedly performed.

[0047] In this embodiment, the other end of the gas circuit L3 is open to the atmosphere, and therefore air is introduced as a gas by the pump P1, but the other end of the gas circuit L3 may be connected to a tank filled with another gas (e.g., nitrogen, etc.). In this case, the other gas is introduced into or discharged from the branching portion 23, and the blood removal process and the blood return process are alternately and repeatedly performed.

[0048] As described above, in this embodiment, the extracorporeal circulation unit 8, which is a blood purification circuit, includes the arterial blood circuit L1, the venous blood circuit L2, the branch 23, the arterial clamp V1, and the venous clamp V2. Furthermore, of the three circuits in the extracorporeal circulation unit 8, only the gas circuit L3 is equipped with a pump P1, while the arterial blood circuit L1 and the venous blood circuit L2, which are blood circuits, are not equipped with pumps. Furthermore, the number of devices and components installed in the blood circuits that could increase the amount of blood circulating extracorporeally is reduced. In this configuration, blood removal and blood return can be alternately performed by controlling the pump P1, the arterial clamp V1, and the venous clamp V2. Details of this control will be described later.

[0049] [Processing Unit] Next, as shown in FIG. 2, the processing unit 6 according to this embodiment is composed of a processor 6a and a memory 6b.

[0050] The processor 6a is composed of a GPU (Graphics Processing Unit) or a CPU (Central Processing Unit) and functions as a processing unit that controls each component device of the blood purification apparatus 1 based on various programs stored in the memory 6b. Specifically, the processor 6a reads and executes from the memory 6b a program for performing treatment to purify the patient's blood or a program for running the OS. In particular, the processor 6a determines whether the blood flow rate is being maintained appropriately during the blood removal process and blood return process of the blood purification apparatus 1, and if the blood flow rate is not appropriate, executes a process to control the operation of the pump P1. The processor 6a may be composed of a single GPU or CPU, or may be composed of a combination of multiple CPUs or GPUs.

[0051] The memory 6b is composed of ROM, RAM, non-volatile memory, HDD, etc., and functions as a storage unit. The ROM stores instructions and commands for performing treatment to purify the patient's blood as a program. It also stores a blood flow rate table consisting of blood flow rate information set for each patient H, and setting information for controlling the pump P1 and each clamp corresponding to the blood flow rate information. The RAM is used to write and read data while the program stored in the ROM is being processed by the processor 6a. The non-volatile memory is a storage device to which data is written and read as the program is executed, and the data written therein is retained even after execution of the program has ended.

[0052] In particular, in this embodiment, a program is stored for determining whether the blood flow rate is being maintained appropriately during the blood removal process and the blood return process of the blood purification apparatus 1. In addition, a program is also stored for calculating how to correct the drive of the pump P1 when it is determined that the blood flow rate is not appropriate.

[0053] Next, the functional configuration of the processing unit 6 of the blood purification apparatus 1 according to this embodiment will be described with reference to Fig. 4. In particular, Fig. 4 shows other components of the blood purification apparatus 1 in addition to the processing unit 6, and also shows the flow of information and signals between these components.

[0054] 4, the processing unit 6 has a calculation unit 61, a pump control unit 62, a clamp control unit 63, and a storage unit 64. Each of these units is realized by the functioning of the processor 6a and memory 6b of the processing unit 6 themselves, or by the processor 6a reading and executing a program stored in the memory 6b.

[0055] As shown in Fig. 4, the calculation unit 61 receives patient information about a patient H undergoing blood purification treatment via the input unit 4a. Here, the patient information includes at least the patient's weight, and also includes information such as the patient's name, age, sex, and treatment history. The calculation unit 61 also reads out blood flow information stored in the memory unit 64. Here, the blood flow information is information related to the blood flow rate during treatment set for each patient H, and is determined based particularly on the patient's weight, condition, and treatment details. Therefore, the blood flow information differs for each patient H and is updated in accordance with the patient H's growth, changes in condition, etc.

[0056] As can be seen from FIG. 4 , the calculation unit 61 reads blood flow rate information corresponding to the received patient information from the blood flow rate table stored in the storage unit 64. That is, the calculation unit 61 identifies the patient H from the patient information and extracts blood flow rate information, which is a setting condition for the treatment of the patient H. The calculation unit 61 also generates pump drive information related to the control of the pump P1 and clamp drive information related to the control of each clamp, which are necessary to ensure the blood flow rate. More specifically, the calculation unit 61 determines the amount of air introduced and discharged per cycle (one stroke) of the pump P1 in the alternating control of the blood removal process and the blood return process, and determines the timing of opening and closing the arterial clamp V1 and the venous clamp V2 corresponding to the drive of the pump P1. As a result, the calculation unit 61 determines the amount of air introduced and discharged per cycle in the alternating control of the blood removal process and the blood return process according to the weight of the patient H. Furthermore, the calculation unit 61 transmits the generated pump drive information to the pump control unit 62 and clamp drive information related to the control of each clamp to the clamp control unit 63. The calculation unit 61 then stores the generated pump drive information and clamp drive information in the storage unit 64 as setting information.

[0057] As shown in FIG. 4 , the calculation unit 61 constantly or periodically receives detection signals related to the detection of the blood level at the branching portion 23 from the liquid level detection unit 24. Here, the detection signals refer to signals related to ultrasonic waves received by the receiving elements 24c and 24d of the liquid level detection unit 24, particularly signals related to the wavelength of the ultrasonic waves. Based on the received detection signals, the calculation unit 61 determines whether blood is present at the position of the sensor consisting of the oscillation element 24a and the receiving element 24c, and also determines whether blood is present at the position of the sensor consisting of the oscillation element 24b and the receiving element 24d. Furthermore, the calculation unit 61 determines that the blood level has passed (i.e., the liquid level has been present) when the determination of the presence or absence of blood is switched at each sensor. This allows the calculation unit 61 to calculate the travel time for the liquid level to move from one sensor to the other.

[0058] The calculation unit 61 then compares the calculated actual travel time with a theoretical travel time calculated based on the pump drive information read from the storage unit 64 to determine the drive status of the pump P1. The theoretical time is determined by the rotational speed of the pump P1 and the discharge or suction volume per rotation. Therefore, the calculation unit 61 can calculate the theoretical travel time at the time of calculating the actual travel time using the rotational speed included in the pump drive information generated for controlling the pump P1. The drive status of the pump P1 is expressed as being superior or inferior to the originally expected drive status of the pump P1. For example, a poor drive status of the pump P1 refers to the degree of deterioration over time of the pump P1 and a portion (pump segment) of the gas circuit L3 in contact with the pump P1 due to prolonged operation of the pump P1. If the actual travel time is slower than the theoretical time, deterioration over time is occurring.

[0059] Since the distance traveled by one of the two sensors provided at branch 23 is known in advance, calculation unit 61 may calculate the actual flow velocity of the blood at branch 23 by subtracting the time it takes for the liquid surface to travel between the two sensors from the distance between the two sensors. In this case, by including information related to the flow velocity of the blood at branch 23 in the setting information or blood flow rate information, pump drive information may be determined based on the blood flow velocity instead of the time it takes for the liquid surface to travel.

[0060] When the calculation unit 61 determines that the drive state of the pump P1 is different from the originally intended drive state, it corrects the pump drive information to match the drive state of the pump P1 to the originally intended drive state. For example, when it determines that the drive state of the pump P1 is inferior to the originally intended drive state, it corrects the pump drive information to increase the rotation rate of the pump P1 to compensate for deterioration over time. That is, when the actual travel time is slower than the theoretical time, the calculation unit 61 determines that the discharge or suction volume per rotation of the pump P1 has decreased and increases the rotation rate of the pump so that the one-stroke volume of the pump P1 approaches the originally intended volume. On the other hand, when the actual travel time is faster than the theoretical time, the calculation unit 61 determines that the discharge or suction volume per rotation of the pump P1 is too large and decreases the rotation rate of the pump so that the one-stroke volume of the pump P1 approaches the originally intended volume.

[0061] When the pump drive information is corrected, the calculation unit 61 transmits the corrected pump drive information to the pump control unit 62. In this case, if there is also a change in the control (opening / closing timing) of each clamp, the calculation unit 61 may also correct the clamp drive information and transmit the corrected clamp drive information to the clamp control unit 63.

[0062] Based on the received pump drive information (including the corrected pump drive information), the pump control unit 62 generates a pump drive signal for controlling the pump P1 to a desired state. Here, the desired state includes the rotation direction of the pump P1, the timing for switching the rotation direction, and the rotation amount. The pump control unit 62 then transmits the generated pump drive signal to the pump P1.

[0063] Based on the received clamp drive information (including the corrected clamp drive information), the clamp control unit 63 generates an arterial clamp drive signal for controlling the arterial clamp V1 to a desired open / close state, and generates a venous clamp drive signal for controlling the venous clamp V2 to a desired open / close state. Here, the desired open / close state includes the timing of opening and closing by the clamp. The clamp control unit 63 then transmits the generated arterial clamp drive signal to the arterial clamp V1 and the generated venous clamp drive signal to the venous clamp V2.

[0064] (Processing in Blood Purification Apparatus) Next, the processing related to the treatment of patient H by the blood purification apparatus 1 according to this embodiment will be described with reference to Figs. 5 to 9. Fig. 5 is a flowchart showing the flow of treatment in the blood purification apparatus 1 according to this embodiment. Fig. 6 is a schematic diagram showing the drive pattern during blood purification processing in the blood purification apparatus 1 according to this embodiment. Fig. 7 is a configuration diagram of the extracorporeal circulation unit 8 during blood removal in the blood purification apparatus 1 according to this embodiment. Fig. 8 is a configuration diagram of the extracorporeal circulation unit 8 during blood return in the blood purification apparatus 1 according to this embodiment. Fig. 9 is a flowchart showing the flow of correction in the blood purification apparatus 1 according to this embodiment.

[0065] First, as shown in Fig. 5, the processing unit 6 determines whether or not patient information has been received (S1). Specifically, when the administrator of the blood purification apparatus 1 operates the input unit 4a to input information related to patient H, the patient information is transmitted from the input unit 4a to the calculation unit 61 of the processing unit 6. If the processing unit 6 includes a communication unit, the processing unit 6 may receive patient information from an external device via the communication unit. If the patient information has not been received (S1: No), treatment-related settings cannot be made, and the process does not proceed to the next step in this flow.

[0066] Next, when the patient information is received by the processing unit 6 (S1: Yes), the processing unit 6 executes a preparation process for blood purification treatment (S2). Specifically, the processor 6a of the processing unit 6 reads the preparation process program stored in the memory 6b, determines the treatment settings corresponding to patient H from the patient information, and sequentially executes processes related to priming, gas purging, and initial blood removal.

[0067] Next, the processing unit 6 reads out blood flow information corresponding to the received patient information (S3). Specifically, the calculation unit 61 of the processing unit 6 refers to the blood flow table stored in the memory unit 64 and reads out the blood flow information corresponding to the received patient information.

[0068] Next, the processing unit 6 generates initial pump drive information and initial clamp drive information (S4). Specifically, the calculation unit 61 of the processing unit 6 determines the amount of air introduced and discharged per cycle of the pump P1 in the alternating control of the blood removal process and the blood return process so as to correspond to the read blood flow rate information, and generates pump drive information corresponding to this determination. The calculation unit 61 of the processing unit 6 also determines the timing of opening and closing the arterial clamp V1 and the venous clamp V2 corresponding to the drive of the pump P1, and generates clamp drive information corresponding to this determination.

[0069] Next, the processing unit 6 stores the generated pump drive information and clamp drive information as setting information in the storage unit 64 (S5). This stores control information for the component devices in the treatment of the patient H that is about to begin.

[0070] Next, the pump drive information generated by the calculation unit 61 of the processing unit 6 is transmitted to the pump control unit 62, and the clamp drive information is transmitted to the clamp control unit 63. Subsequently, the pump control unit 62 generates a pump drive signal for controlling the pump P1 to a desired state based on the received pump drive information. In other words, the pump control unit 62 generates a pump drive signal to be actually transmitted to the pump P1 based on the received pump drive information. Meanwhile, the clamp control unit 63 generates an arterial clamp drive signal for controlling the arterial clamp V1 to a desired open / close state, and a venous clamp drive signal for controlling the venous clamp V2 to a desired open / close state based on the received clamp drive information. In other words, the clamp control unit 63 generates clamp drive signals to be actually transmitted to the arterial clamp V1 and the venous clamp V2 based on the received clamp drive information. The generated pump drive signal is then transmitted to the pump P1, the arterial clamp drive signal is transmitted to the arterial clamp V1, and the venous clamp drive signal is transmitted to the venous clamp V2, completing the setting of the treatment procedure for the patient H (S6).

[0071] Next, the pump P1, the arterial clamp V1, and the venous clamp V2 perform predetermined operations at predetermined times to perform blood purification (S7). Specifically, as can be seen from Figures 6 and 7, when the pump P1 rotates in the reverse direction, the arterial clamp V1 opens the flow path and the venous clamp V2 closes the flow path. As a result, air is drawn from the branch 23, blood is drawn from the patient H, and the drawn blood passes through the blood purifier 5 and accumulates in the branch 23 (blood removal process). Thereafter, as can be seen from Figures 6 and 8, when the pump P1 rotates in the forward direction, the arterial clamp V1 closes the flow path and the venous clamp V2 opens the flow path. As a result, air is drawn toward the branch 23, and the blood accumulated in the branch 23 is returned to the patient H (blood return process).

[0072] In such blood removal and blood return processes, the blood flow rate during the process can be adjusted simply by changing the air discharge and suction rates of the pump P1. That is, simply by controlling the rotational speed of the pump P1, blood flow rates of 15 ml / min or less, 3 ml / min or less, and 100 ml / min or more, 600 ml / min or more can be easily accommodated.

[0073] Next, the processing unit 6 determines whether or not the treatment for patient H has been completed (S8). If the treatment for patient H has not been completed (S8: No), the process returns to the blood purification process of S7. That is, the blood removal process and the blood return process, which are blood purification processes, are repeated until the treatment is completed, and the treatment for patient H progresses. Then, when a predetermined cycle or time has elapsed, it is determined that the treatment has been completed (S8: Yes), and this flow ends.

[0074] During the blood purification process in S7 of FIG. 5 , the processing unit 6 also repeatedly executes the pump drive correction flow shown in FIG. 9 in parallel. In this correction process, the processing unit 6 first determines whether a predetermined time has elapsed since the start of treatment (S11). Specifically, the calculation unit 61 of the processing unit 6 compares the elapsed time since the start of treatment of the pump P1 with the correction flow start time stored in the memory unit 64, and determines whether or not to perform correction processing. Here, the predetermined time may be, for example, every one minute, every ten minutes, or every hour from the start of treatment. If the predetermined time has not elapsed (S11: No), no correction is necessary, and this flow ends.

[0075] Next, if a predetermined time has elapsed (S11: Yes), calculation unit 61 calculates the travel time required for the blood level to move from one sensor provided at branching unit 23 to the other sensor based on a detection signal related to the detection of the blood level at branching unit 23. Specifically, calculation unit 61 determines whether or not blood is present at the position of the sensor consisting of oscillation element 24a and reception element 24c, and also determines whether or not blood is present at the position of the sensor consisting of oscillation element 24b and reception element 24d, based on the received detection signal. Furthermore, calculation unit 61 determines that the blood level has passed at the timing when each sensor switches its determination of whether or not blood is present, and calculates the time difference between the timings at which each sensor switches its determination as the travel time.

[0076] Next, the processing unit 6 determines whether correction related to pump drive is necessary (S13). Specifically, the calculation unit 61 compares the calculated actual travel time with a theoretical travel time calculated based on the pump drive information read from the storage unit 64, and determines the drive state of the pump P1. Furthermore, if there is a discrepancy between the actual travel time and the theoretical travel time, the calculation unit 61 determines that correction related to pump drive is necessary. Here, the calculation unit 61 may calculate the degree of discrepancy between the actual travel time and the theoretical travel time. For example, if the theoretical time is set to 100%, the calculation unit 61 calculates what percentage of the actual travel time it represents. If there is no discrepancy (S13: No), no correction is necessary, and this flow ends.

[0077] Next, if there is a discrepancy between the theoretical travel time and the actual travel time (S13: Yes), the processing unit 6 corrects the pump drive information (S14). Specifically, the calculation unit 61 changes the rotation rate of the pump so that the drive state of the pump P1 matches the originally expected drive. For example, if the actual travel time is 5% slower than the theoretical travel time, the calculation unit 61 corrects the pump drive information so as to increase the rotation rate of the pump P1 by 5% to compensate for the 5% difference.

[0078] Next, the processing unit 6 regenerates a pump drive signal based on the corrected pump drive information, and retransmits the regenerated pump drive signal to the pump P1 (S15). Specifically, the pump control unit 62 of the processing unit 6 receives the regenerated pump drive information from the calculation unit 61 and, based on the pump drive information, regenerates a pump drive signal for controlling the pump P1 to a desired state. The pump control unit 62 then transmits the regenerated pump drive signal to the pump P1. This changes the rotation rate of the pump P1, so that the discharge and suction volumes (one-stroke volume) in one cycle of the pump P1 become the required volumes, enabling more accurate blood purification processing.

[0079] (Effects of the First Embodiment) In this embodiment, of the three circuits, only the gas circuit L3 is provided with the pump P1, and the arterial blood circuit L1 and the venous blood circuit L2, which are the blood circuits, are not provided with pumps. As a result, no pump that causes pressure fluctuations in the extracorporeal circulation section during the blood removal and return processes is present in the blood circuits, and no pressure fluctuations due to the operation of the pump P1 occur in the extracorporeal circulation section 8. In other words, pressure fluctuations in the extracorporeal circulation section 8 are significantly suppressed compared to when a conventional blood pump is provided in the blood circuit.

[0080] In this embodiment, the arterial blood circuit L1 and the venous blood circuit L2 do not have pumps, which suppresses an increase in the amount of blood circulating extracorporeally due to the pumps. Furthermore, the arterial blood circuit L1 and the venous blood circuit L2 are provided with only the branching portion 23 and clamps, which suppresses an increase in the amount of blood circulating extracorporeally due to various sensors, valves, etc. In other words, the amount of blood circulating extracorporeally is significantly reduced compared to when multiple components are provided in a blood circuit as in the past.

[0081] In this embodiment, because blood removal and blood return are performed alternately, the amount of blood processed at one time is halved compared to when blood removal and blood return are performed simultaneously. On the other hand, for typical adult patients, simultaneous processing is more necessary to shorten treatment time. However, for newborn or pediatric patients, whose bodies have a small amount of blood, the amount of blood to be treated is small, so halving the amount of blood processed at one time does not pose a problem and does not impose a burden on treatment.

[0082] This device is particularly effective for patients with low body weight, such as newborns and children, and its effectiveness will be explained with reference to Figure 10. Figure 10 shows an example of conditions for blood purification treatment for newborns and children using a conventional blood purification device, and is based on the 2016 AKI (Acute Kidney Injury) Treatment Guidelines (Journal of the Japanese Society of Nephrology 2017; 59(4): 419-533). A conventional blood purification device has a blood pump installed in the arterial blood circuit, and each blood circuit is equipped with multiple components such as sensors and valves.

[0083] As shown in Figure 10, the amount of blood drawn by a blood pump (blood flow rate) for a newborn patient weighing 3 kg is 3 to 15 ml / min. Furthermore, the blood flow rate for a pediatric patient weighing 10 kg is 10 to 50 ml / min. When compared with the blood flow rate of a typical adult patient (200 mL / min), this setting represents a ratio of 1.5% to 25%. Furthermore, the cross-sectional area of ​​a blood purifier for a patient weighing 10 kg or less is less than half that for a patient weighing 15 kg.

[0084] Furthermore, in conventional blood purification devices, for patients weighing less than 10 kg, the priming solution basically had to be red blood cells ± albumin (A) or albumin (B). This is because the amount of extracorporeally circulating blood in the blood circuit of conventional blood purification devices increases, and the target of using a priming solution of approximately 10% or less of the body's blood volume cannot be achieved with saline (C), making it necessary to use blood (red blood cells, albumin) as the priming solution. However, using blood as the priming solution requires blood transfusion, which increases the risk of infection.

[0085] On the other hand, in the blood purification device 1 of this embodiment, the amount of extracorporeally circulating blood is significantly reduced compared to conventional devices, so that even for patients weighing less than 10 kg, saline (C) can be used as the priming solution. This eliminates the need for blood transfusion and the risk of infection, making it easier to ensure safety during treatment.

[0086] In addition, in conventional blood purification devices, the amount of blood drawn per rotation is fixed because the blood pump is located on the blood flow path, and pressure fluctuations cannot be adjusted according to the patient's weight.In contrast, in the blood purification device 1 of this embodiment, the pump P1 is located on the gas circuit L3, making it possible to adjust the blood flow rate to 3 to 15 ml / min, which is necessary for the weight of newborn and pediatric patients, as well as the pressure fluctuations.

[0087] (Modification of the First Embodiment) In the above embodiment, in order to minimize the amount of blood circulating extracorporeally, the arterial blood circuit L1 and the venous blood circuit L2 are simply provided with clamps and branches 23, but in consideration of ensuring the safety of the patient H during treatment and minimizing the amount of blood circulating extracorporeally, an air bubble sensor or a pressure sensor may be provided. For example, an air bubble sensor may be provided near the arterial clamp V1.

[0088] In the above embodiment, the arterial blood circuit L1 and the venous blood circuit L2 are connected by a Y-shaped tube 21, and a single puncture needle 22 is inserted into the patient H. However, this is not limiting as long as blood removal and blood return can be alternately repeated. For example, as shown in Fig. 11, a double-needle configuration may be used in which a puncture needle is connected to each blood circuit. That is, an arterial (blood removal) puncture needle 81 is connected to the arterial blood circuit L1 via a connector 71, and a venous (blood return) puncture needle 82 is connected to the venous blood circuit L2 via a connector 72.

[0089] Furthermore, in the above embodiment, the opening and closing of each clamp is controlled by the calculation unit 61 of the processing unit 6 based on the blood flow rate of the pump P1 (i.e., the blood flow rate per stroke), but the control may be based on the driving time of the pump P1. In other words, the opening and closing of each clamp may be controlled based on time instead of blood flow rate.

[0090] Second Embodiment In the first embodiment, the branching portion 23 was provided in the venous blood circuit L2, but it may also be provided in the arterial blood circuit L1. A blood purification device having such a configuration will be described as the second embodiment with reference to Fig. 12. Fig. 12 is a configuration diagram of the extracorporeal circulation portion of the blood purification device according to this embodiment. Note that only the parts that differ from the first embodiment will be described, and descriptions of the same parts will be omitted, and the same reference numerals will be used in the drawings.

[0091] 12, the extracorporeal circulation unit 108 has three circuits, an arterial blood circuit L101, a venous blood circuit L102, and a gas circuit L3, as well as a branching unit 123 connecting the venous blood circuit L102 and the gas circuit L3. The extracorporeal circulation unit 108 has the same basic components as the extracorporeal circulation unit 8 according to the first embodiment, and differs only in the arrangement of the components and the length of each blood circuit.

[0092] 12, one end of the arterial blood circuit L101 is connected via a Y-shaped tube 21 to a single puncture needle 22 inserted into the arm of the patient H, and the other end is connected to the blood inlet 5a of the blood purifier 5. An arterial clamp V1 is provided near the one end of the arterial blood circuit L101. Furthermore, a branch 123 is provided in the arterial blood circuit L101.

[0093] In this embodiment, the branch 123 is located between the blood purifier 5 and the arterial clamp V1. The arterial blood circuit L101 extending from the arterial clamp V1 is connected to the side of the branch 123, and the arterial blood circuit L101 extending to the blood inlet 5a of the blood purifier 5 is connected to the bottom located vertically below. Furthermore, one end of the gas circuit L3 is connected to the top of the branch 123 located vertically above. Similarly to the branch 23 according to the first embodiment, a liquid level detector 24 for detecting the liquid level of the blood stored in the branch 123 is provided around the branch 123.

[0094] With this structure of the branching part 123, blood drawn from the patient H can be introduced from the side of the branching part 123, and the introduced blood is temporarily stored in the branching part 123. In addition, the stored blood can be led from the bottom of the branching part 123 to the blood purifier 5 via the arterial blood circuit L101.

[0095] 12, one end of the venous blood circuit L102 is connected via a Y-shaped tube 21 to a single puncture needle 22 inserted into the arm of patient H, and the other end is connected to the blood outlet 5b of the blood purifier 5. A venous clamp V2 is provided on the venous blood circuit L102. One end of the gas circuit L3 is connected to the top of the branch 123, and the other end is open to the atmosphere. In addition, a pump P1 is provided on the gas circuit L3.

[0096] In this embodiment, when performing blood removal, the pump P1 is rotated in the reverse direction while the arterial clamp V1 opens the flow path and the venous clamp V2 closes the flow path. This causes air to be drawn from the branch 123 to the gas circuit L3, and blood drawn from the patient H is introduced into the branch 123 from the side of the branch 123 via the arterial blood circuit L101 and stored therein. On the other hand, when performing blood return, the pump P1 is rotated in the forward direction while the arterial clamp V1 closes the flow path and the venous clamp V2 opens the flow path. This causes air to be drawn into the gas circuit L3 from the gas circuit L3 toward the branch 123, and blood stored in the branch 123 is drawn out from the bottom of the branch 123 and introduced into the blood purifier 5 via the arterial blood circuit L101. The blood purified by the blood purifier 5 is then returned to the patient H via the venous blood circuit L102. The above-described processes are alternately repeated to treat the patient H.

[0097] (Effects of the Second Embodiment) In this embodiment, of the three circuits, only the gas circuit L3 is provided with the pump P1, and the arterial blood circuit L1 and the venous blood circuit L2, which are the blood circuits, are not provided with pumps, thereby reducing the number of devices and components that can increase the amount of blood circulating extracorporeally in the blood circuits. As a result, as in the first embodiment, pressure fluctuations in the extracorporeal circulation section are significantly suppressed compared to when a conventional blood pump is provided in the blood circuit. Furthermore, the amount of blood circulating extracorporeally is significantly reduced compared to when a conventional multiple components are provided in the blood circuit.

[0098] Furthermore, as in the first embodiment, by controlling the pump P1, arterial clamp V1, and venous clamp V2, blood removal and blood return can be performed alternately, so that the burden of treatment is not placed on newborn or pediatric patients who have a small amount of blood in their bodies.

[0099] (Variation of the Second Embodiment) In the above embodiment, the branch 123 is provided in the arterial blood circuit L101, but not in the venous blood circuit L102. However, as in the first embodiment, the branch 123 may also be provided in the venous blood circuit L102. That is, the arterial blood circuit L101 and the venous blood circuit L102 may each be provided with a branch 123, and a gas circuit L3 and a pump P1 may be provided at each branch. Even in this case, a configuration is adopted in which the pump P1 is provided only in the gas circuit L3, and no pump is provided in the blood circuit. This reduces the number of devices and components installed in the blood circuit that could increase the amount of blood circulating extracorporeally, thereby enabling pressure fluctuations in the extracorporeal circulation section to be controlled while reducing the amount of blood circulating extracorporeally.

[0100] <Embodiments of the Present Disclosure> A first embodiment of the present disclosure is a blood purification device having a blood purifier that purifies the blood of a patient, an arterial blood circuit that serves as a blood flow path for introducing the blood withdrawn from the patient into the blood purifier, a venous blood circuit that serves as a blood flow path from the blood purifier to the patient, and a gas circuit that serves as an air flow path and is connected to a branching section that branches off either the arterial blood circuit or the venous blood circuit, wherein the blood purification device further comprises an arterial clamp to which the arterial blood circuit can be attached and that can open and close the blood flow path of the arterial blood circuit, a venous clamp to which the venous blood circuit can be attached and that can open and close the blood flow path of the venous blood circuit, a pump that can introduce or extract air into or from the gas circuit, and a valve that connects the pump, the arterial blood circuit, and a valve that connects the arterial blood circuit to the gas circuit. a pump controller that controls the rotation direction of the pump and alternately introduces the gas into the branch and discharges the gas from the branch, thereby alternately removing and returning the blood from the patient; and a clamp controller that controls the arterial clamp to open the flow path of the arterial blood circuit while the venous clamp closes the flow path of the venous blood circuit during the blood removal process, and controls the arterial clamp to close the flow path of the arterial blood circuit while the venous clamp opens the flow path of the venous blood circuit during the blood return process.

[0101] In this way, since the blood circuit does not include a pump that causes pressure fluctuations in the blood circuit during blood removal and blood return, pressure fluctuations due to pump operation do not occur in the blood circuit, and an increase in the amount of extracorporeal blood circulating due to the pump is suppressed. Furthermore, even when the blood flow rate is relatively small, it is possible to accurately control the blood flow rate, and accurate treatment can be performed without any errors in the blood flow rate.

[0102] In a second embodiment of the present disclosure, the pump is provided only in the gas circuit among the arterial blood circuit, the venous blood circuit, and the gas circuit in the first embodiment, thereby enabling accurate control of the blood flow rate even when the blood flow rate is relatively small, thereby preventing errors in the blood flow rate and enabling accurate treatment.

[0103] In a third embodiment of the present disclosure, in the first embodiment, the processing unit includes a calculation unit that generates pump drive information for controlling the pump and clamp drive information for controlling the arterial clamp and the venous clamp based on input patient information, thereby enabling accurate control of blood flow even when the blood flow is relatively small, thereby preventing blood flow error and enabling accurate treatment.

[0104] A fourth embodiment of the present disclosure is the third embodiment, wherein the calculation unit determines the amount of gas introduced and discharged per cycle in the alternating control of the blood removal process and the blood return process in accordance with the patient's weight, thereby enabling accurate, optimal treatment corresponding to the patient's weight.

[0105] In a fifth embodiment of the present disclosure, in the third embodiment, the calculation unit determines the driving state of the pump based on the time it takes for the blood surface to move over a predetermined distance at the branching portion, thereby enabling precise control of the blood flow rate and enabling accurate treatment without any errors in the blood flow rate.

[0106] A sixth embodiment of the present disclosure is the fifth embodiment, in which the calculation unit corrects the pump drive information according to the drive state of the pump and changes the rotation rate of the pump. This makes it possible to maintain an appropriate blood flow rate and perform accurate treatment even if the pump discharge and suction rates change due to deterioration of parts of the blood purification device, etc.

[0107] A seventh embodiment of the present disclosure is the fifth or sixth embodiment, in which two liquid level detectors are provided at the branching section, and the calculation unit calculates the travel time based on the detection signals of the liquid level detectors. This makes it possible to precisely control the blood flow rate, and accurate treatment can be performed without any error in the blood flow rate.

[0108] An eighth embodiment of the present disclosure is that in any of the first to seventh embodiments, the patient includes a patient with a very small body weight, such as a newborn or a child, thereby enabling precise treatment to be performed on a patient with a very small body weight.

[0109] A ninth embodiment of the present disclosure is a blood purification circuit connected to a blood purifier that purifies a patient's blood, the blood purification circuit comprising: an arterial blood circuit that serves as a blood flow path for introducing the blood removed from the patient into the blood purifier; a venous blood circuit that serves as a blood flow path from the blood purifier to the patient; a gas circuit that serves as an air flow path and is connected to a branching point that branches off either the arterial blood circuit or the venous blood circuit; and a pump connected only to the gas circuit among the arterial blood circuit, the venous blood circuit, and the gas circuit, in which blood removal and blood return processes are alternately performed depending on the operating state of the pump.

[0110] In this way, the pump that causes pressure fluctuations in the blood purification circuit during blood removal and blood return is not connected to the blood circuit, so pressure fluctuations caused by the operation of the pump do not occur in the blood purification circuit, and an increase in the amount of blood circulating extracorporeally due to the pump is suppressed.

[0111] REFERENCE SIGNS LIST 1 Blood purification device 2 Base unit 3 Main body 4 Display 5 Blood purifier 6 Processing section 7 Internal piping section 8 Extracorporeal circulation section (blood purification circuit) 23 Branch section 24 Liquid level detection section 61 Calculation section 62 Pump control section 63 Clamp control section 64 Memory section L1 Arterial blood circuit L2 Venous blood circuit L3 Gas circuit V1 Arterial clamp V2 Venous clamp P1 Pump H Patient

Claims

1. A blood purification device having a blood purifier for purifying a patient's blood, an arterial blood circuit serving as a blood flow path for introducing the blood removed from the patient into the blood purifier, a venous blood circuit serving as a blood flow path from the blood purifier to the patient, and a gas circuit connected to a branching section that branches off either the arterial blood circuit or the venous blood circuit and serving as an air flow path, the device comprising: an arterial clamp capable of opening and closing the blood flow path of the arterial blood circuit to which the arterial blood circuit is attached; a venous clamp capable of opening and closing the blood flow path of the venous blood circuit to which the venous blood circuit is attached; a pump capable of introducing and evacuating air to and from the gas circuit; and a processing section that controls the pump, the arterial clamp, and the venous clamp, the processing section controlling the pump rotation direction and alternately introducing and evacuating the gas to and from the branching section, thereby alternately removing and returning the blood from the patient. a clamp control unit that controls the arterial clamp to open the flow path of the arterial blood circuit while the venous clamp to close the flow path of the venous blood circuit during the blood removal process, and the arterial clamp to close the flow path of the arterial blood circuit while the venous clamp to open the flow path of the venous blood circuit during the blood return process.

2. The blood purification device according to claim 1, wherein the pump is provided only in the gas circuit among the arterial blood circuit, the venous blood circuit, and the gas circuit.

3. The blood purification device according to claim 1, wherein the processing unit includes a calculation unit that generates pump drive information for controlling the pump based on input patient information, and clamp drive information for controlling the arterial clamp and the venous clamp.

4. A blood purification device as described in claim 3, wherein the calculation unit determines the amount of gas introduced and discharged per cycle in the alternating control of the blood removal process and the blood return process according to the weight of the patient.

5. The blood purification device according to claim 3, wherein the calculation unit determines the driving state of the pump based on the time it takes for the blood surface to move over a predetermined distance at the branching portion.

6. The blood purification device according to claim 5, wherein the calculation unit corrects the pump drive information in accordance with the drive state of the pump, and changes the rotation rate of the pump.

7. The blood purification device according to claim 5 or 6, wherein two liquid level detectors are provided at the branching section, and the calculation unit calculates the travel time based on detection signals from the liquid level detectors.

8. The blood purification device according to claim 1, wherein the patient includes a patient of very small weight, such as a neonatal or pediatric patient.

9. A blood purification circuit connected to a blood purifier that purifies a patient's blood, comprising: an arterial blood circuit that serves as a blood flow path for introducing the blood removed from the patient into the blood purifier; a venous blood circuit that serves as a blood flow path from the blood purifier to the patient; a gas circuit that serves as an air flow path and is connected to a branching point that branches off either the arterial blood circuit or the venous blood circuit; and a pump connected only to the gas circuit among the arterial blood circuit, the venous blood circuit, and the gas circuit, in which blood removal and return processes are alternately performed depending on the operating state of the pump.

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