Blood purification device, control method thereof, and program

Abstract

To make it possible to suppress fluctuations in pressure changes on inlet sides of two pumps without additional sensors.SOLUTION: A blood purification device 1 according to the present disclosure comprises: a blood purifier 100; an arterial blood circuit 130; a venous blood circuit 140; a replacement fluid line 150; a dialysate line 110; a drainage line 120; a blood pump 131; a supply pump 111; a drainage pump 121; a replacement fluid pump 151; and a control unit. The control unit modulates, in opposite phases, the flow rates of any two of the supply pump 111, the drainage pump 121 and the replacement fluid pump 151 that are being driven.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a blood purification device, a control method thereof, and a program. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2016-147117 (Patent Document 1) discloses a blood purification device for purifying a patient's blood while circulating it extracorporeally. In this blood purification device, after inserting an arterial puncture needle and a venous puncture needle into the patient, driving the blood pump causes the patient's blood to be circulated extracorporeally in the arterial blood circuit and the venous blood circuit. Furthermore, when the blood pump's supply pump is driven, the dialysate in the multiple storage bags flows toward the dialyzer, and when the drainage pump is driven, the dialysate (drainage) from the dialyzer flows toward the storage bag. Driving the fluid replacement pump also allows the dialysate in the storage bag to be supplied to the venous blood circuit for fluid replacement. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-147117 Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of pumps used in blood purification devices, whose flow rate changes due to the influence of inlet pressure (for example, peristaltic pumps), if the phase difference between the pulsations of two pumps in a communicating flow path is constant at the start of operation, the change in inlet pressure will be maintained constant. However, if the phase difference between the pulsations of the two pumps at the start of operation changes, the change in inlet pressure will fluctuate with each operation, causing the flow rate to fluctuate with each operation, resulting in unstable pump operation.

[0005] Therefore, some blood purification devices are equipped with a phase-detecting sensor to control the phase difference between the pulsations of the two pumps so that the phases of the pulsations of the two pumps are always the same when starting operation. However, the need for a phase-detecting sensor in these blood purification devices increases manufacturing costs, and the control to align the phases may cause the pumps to be driven, resulting in unnecessary fluid delivery.

[0006] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a blood purification device, a control method thereof, and a program that can suppress fluctuations in pressure changes on the inlet sides of two pumps without adding sensors. [Means for solving the problem]

[0007] [1] A blood purifier comprising: an arterial blood circuit connected to the blood purifier for introducing blood into the blood purifier; a venous blood circuit connected to the blood purifier for discharging blood from the blood purifier; a replacement fluid line connected to the arterial blood circuit or the venous blood circuit for supplying replacement fluid; a dialysate line for supplying dialysate to the blood purifier; a drainage line for draining effluent discharged from the blood purifier; a blood pump provided in the arterial blood circuit for pumping blood; a supply pump provided in the dialysate line for pumping the dialysate; a drainage pump provided in the drainage line for pumping the effluent; a replacement fluid pump provided in the replacement fluid line for pumping the replacement fluid; and a control unit for controlling the flow rates of the supply pump, drainage pump, and replacement fluid pump, wherein the control unit modulates the flow rates of two pumps being driven out of the supply pump, drainage pump, and replacement fluid pump in an inverse cycle.

[0008] In a blood purification device configured in this manner, the control unit modulates the flow rates of two of the pumps being driven, the supply pump, the drainage pump, and the replacement pump, in inverse cycles, thereby suppressing fluctuations in pressure changes on the inlet side of the two pumps without adding any additional sensors.

[0009] [2] The blood purification device described in [1], wherein the control unit sets the flow rate to be modulated by each pump so that the total flow rate of the two pumps is the sum of the set flow rates of each pump.

[0010] According to the blood purification apparatus configured in this manner, even if the set flow rates of the two pumps are different, the total flow rate of the two pumps can be controlled to be the same even after modulation.

[0011] [3] The blood purification device according to [2], wherein when the set flow rates of the two pumps are the same, the control unit modulates the flow rates of each pump at the same rate and inversely to the set flow rates.

[0012] According to the blood purification apparatus configured in this manner, fluctuations in pressure change on the inlet side of the two pumps can be suppressed without changing the total flow rate of the two pumps.

[0013] [4] The blood purification device according to any one of [1] to [3], wherein the control unit modulates the flow rates of the two pumps in a rectangular wave pattern with opposite periods.

[0014] According to the blood purification device configured in this manner, fluctuations in pressure change on the inlet side of the two pumps can be suppressed.

[0015] [5] The blood purification device according to any one of [1] to [3], wherein the control unit modulates the flow rates of the two pumps in a triangular wave pattern with opposite periods.

[0016] According to the blood purification device configured in this manner, fluctuations in pressure change on the inlet side of the two pumps can be suppressed.

[0017] [6] The blood purification apparatus according to any one of [1] to [3], wherein the control unit modulates the flow rates of the two pumps in a sinusoidal waveform with opposite periods.

[0018] According to the blood purification device configured in this manner, fluctuations in pressure change on the inlet side of the two pumps can be suppressed.

[0019] [7] The blood purification device described in any one of [1] to [6], wherein the control unit drives the flow rates of the fluid supply pump and the fluid replacement pump, and modulates the flow rate of the fluid supply pump and the flow rate of the fluid replacement pump in inverse cycles.

[0020] According to the blood purification apparatus configured in this manner, fluctuations in pressure change on the inlet side of the fluid supply pump and the fluid replacement pump can be suppressed.

[0021] [8] The blood purification device described in any one of [1] to [6], wherein the control unit drives the flow rates of the supply pump and the drainage pump, and modulates the flow rates of the supply pump and the drainage pump in inverse cycles.

[0022] According to the blood purification apparatus configured in this manner, fluctuations in pressure change on the inlet side of the fluid supply pump and the fluid discharge pump can be suppressed.

[0023] [9] The blood purification device described in any one of [1] to [6], wherein the control unit drives the flow rates of the fluid replacement pump and the drainage pump, and modulates the flow rate of the fluid replacement pump and the flow rate of the drainage pump in inverse cycles.

[0024] According to the blood purification device configured in this manner, fluctuations in pressure change on the inlet side of the fluid replacement pump and the drainage pump can be suppressed.

[0025]

[10] A blood purifier, an arterial blood circuit connected to the blood purifier for introducing blood into the blood purifier, a venous blood circuit connected to the blood purifier for discharging blood from the blood purifier, a replacement fluid line connected to the arterial blood circuit or the venous blood circuit for supplying replacement fluid, a dialysate line for supplying dialysate to the blood purifier, a drainage line for draining drainage discharged from the blood purifier, a blood pump provided in the arterial blood circuit for pumping blood, and a pump provided in the dialysate line. a control unit that controls the flow rates of the supply pump, the drain pump, and the replacement fluid pump, the method comprising the steps of: identifying two pumps that are being driven among the supply pump, the drain pump, and the replacement fluid pump; and modulating the flow rates of the identified two pumps in an inverse cycle.

[0026] According to the control method for a blood purification device configured in this manner, the flow rates of two pumps that are being driven among the fluid supply pump, the fluid drainage pump, and the fluid replacement pump are modulated in inverse cycles, thereby making it possible to suppress fluctuations in pressure changes on the inlet side of the two pumps without adding any additional sensors.

[0027]

[11] A blood purifier, an arterial blood circuit connected to the blood purifier for introducing blood into the blood purifier, a venous blood circuit connected to the blood purifier for discharging blood from the blood purifier, a replacement fluid line connected to the arterial blood circuit or the venous blood circuit for supplying replacement fluid, a dialysate line for supplying dialysate to the blood purifier, a drainage line for draining drainage discharged from the blood purifier, a blood pump provided in the arterial blood circuit for pumping blood, and a dialysate line provided in the dialysate line for draining the dialysate. a supply pump that delivers the drained fluid; a drainage pump that is provided in the drainage line and delivers the drained fluid; a replacement pump that is provided in the replacement line and delivers the replacement fluid; and a control unit that controls the flow rates of the supply pump, the drainage pump, and the replacement pump, wherein the program includes the steps of: identifying two pumps that are being driven from among the supply pump, the drainage pump, and the replacement pump; and modulating the flow rates of the identified two pumps in an inverse cycle.

[0028] According to the program configured in this manner, the flow rates of the two pumps that are being driven out of the supply pump, drainage pump, and replacement pump are modulated in inverse cycles, thereby suppressing fluctuations in pressure changes on the inlet side of the two pumps without adding any additional sensors. [Effects of the Invention]

[0029] According to the present disclosure, the control unit modulates the flow rates of two of the pumps being driven, the supply pump, the drainage pump, and the replacement pump, in inverse cycles, thereby suppressing fluctuations in pressure changes on the inlet side of the two pumps without adding any additional sensors. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 1 is a circuit diagram showing a blood purification device. [Figure 2] FIG. 2 is a block diagram showing a configuration including a control unit of the blood purification device. [Figure 3]10A and 10B are diagrams for explaining changes in pressure on the inlet side of the pump when the phase of pulsation of the supply fluid pump and the replacement fluid pump changes. [Figure 4] 10 shows a graph in which the flow rates of the fluid supply pump and the fluid replacement pump are modulated in a square wave shape. [Figure 5] 10A and 10B are diagrams for explaining changes in the pressure on the inlet side of the pump when the flow rates of the supply fluid pump and the replacement fluid pump are modulated. [Figure 6] Graphs are shown when the flow rates of the supply pump and the replacement pump are modulated in a triangular or sinusoidal waveform. DETAILED DESCRIPTION OF THE INVENTION

[0031] Embodiments of the present disclosure will be described with reference to the drawings. In the drawings referred to below, the same or equivalent components are designated by the same reference numerals.

[0032] In the following description of the embodiments, a blood purification device used in continuous renal replacement therapy (CRRT) will be described. However, the blood purification device may be a blood purification device used in any of plasma exchange (PE), continuous blood purification therapy (CBP), continuous hemodiafiltration (CHDF), continuous hemofiltration (CHF), continuous hemodialysis (CHD), and slow continuous ultrafiltration (SCUF), or may be a blood purification device used in general renal replacement therapy.

[0033] Fig. 1 is a circuit diagram showing the blood purification apparatus 1. First, the overall configuration of the blood purification apparatus 1 will be described with reference to Fig. 1.

[0034] The blood purification device 1 includes a blood purifier 100, a dialysate line 110, a supply pump 111, a drainage line 120, a drainage pump 121, an arterial blood circuit 130, a venous blood circuit 140, a replacement fluid line 150, a replacement fluid pump 151, a first connecting line 160, a first measuring bag 165, a second connecting line 170, a second measuring bag 175, a scale 180, and a syringe pump 190. The type of blood pump 131 is not particularly limited, but is typically a rotary pump. The supply pump 111, the drainage pump 121, and the replacement fluid pump 151 are pumps whose flow rates change depending on the inlet pressure, and are typically peristaltic pumps.

[0035] The arterial blood circuit 130 and the venous blood circuit 140 are blood flow paths that communicate with the blood purifier 100 and through which blood flows. The dialysate line 110 and the drain line 120 are treatment fluid flow paths that communicate with the blood purifier 100 and through which dialysate flows as a treatment fluid.

[0036] Blood purifier 100 includes a semipermeable membrane (blood purification membrane) made of, for example, a hollow fiber membrane inside. Blood purifier 100 has dialysate inlet 101, waste fluid outlet 102, blood inlet 103, and blood outlet 104.

[0037] The dialysate conduit 110 is connected to a dialysate inlet 101 of the blood purifier 100 and supplies dialysate to the blood purifier 100. The upstream end of the dialysate conduit 110 is connected to a supply source 185 that supplies replacement fluid and dialysate. A supply pump 111 that pumps out dialysate is connected to the dialysate conduit 110. The dialysate that flows through the dialysate conduit 110 is supplied into the blood purifier 100. The dialysate conduit 110 and the other conduits described below are soft tubes made of, for example, polyvinyl chloride or polybutadiene.

[0038] The drainage pipeline 120 is connected to the drainage outlet 102 of the blood purifier 100, and carries the drainage discharged from the drainage outlet 102 of the blood purifier 100. The drainage discharged from the blood purifier 100 is discharged from the downstream end of the drainage pipeline 120. A drainage pump 121 is connected to the drainage pipeline 120, and sends out the drainage flowing through the drainage pipeline 120. A filtration pressure sensor 122 that measures the pressure inside the drainage pipeline 120 is provided upstream of the drainage pump 121 in the drainage pipeline 120. A secondary membrane pressure sensor 123 is provided downstream of the filtration pressure sensor 122. Furthermore, a blood leakage sensor 2 is provided upstream of the filtration pressure sensor 122 in the drainage pipeline 120.

[0039] The arterial blood circuit 130 is connected to the blood inlet 103 of the blood purifier 100, and is a circuit for allowing blood to flow into the blood purifier 100. The arterial blood circuit 130 is provided with a blood pump 131 that pumps out blood. In the arterial blood circuit 130, an arterial air trap chamber 132 is provided between the blood pump 131 and the blood purifier 100. The arterial air trap chamber 132 is provided with an inlet pressure sensor 133 that measures the pressure inside the arterial air trap chamber 132.

[0040] Blood collected from the patient's artery via the arterial blood circuit 130 flows through the arterial blood circuit 130, has its pressure measured in the arterial air trap chamber 132, and then flows into the blood purifier 100 from the blood inlet 103. The arterial air trap chamber 132 is provided to prevent air from mixing with the blood in the arterial blood circuit 130.

[0041] The arterial blood circuit 130 is provided with an arterial air bubble sensor 230a, an arterial blood sensor 230b, and an arterial clamp 230c. A substitution fluid line 136 branches off from the arterial blood circuit 130, and a substitution fluid clamp 230d is provided on the substitution fluid line 136. The substitution fluid 20 is, for example, physiological saline.

[0042] An airless monitor 138 is also connected to the arterial blood circuit 130. Specifically, the airless monitor 138 is connected between the arterial air bubble sensor 230a and the blood pump 131 in the arterial blood circuit 130. A vent pressure sensor 139 is connected to the airless monitor 138, and measures the vent pressure of the patient flowing into the arterial blood circuit 130.

[0043] The venous blood circuit 140 is connected to the blood outlet 104 of the blood purifier 100, and is a circuit for discharging blood from the blood purifier 100 and returning the blood to the patient. The venous blood circuit 140 is provided with a venous air trap chamber 141. The venous air trap chamber 141 is provided with a venous circuit pressure sensor 142 that measures the pressure inside the venous air trap chamber 141.

[0044] The blood purified by blood purifier 100 flows through venous blood circuit 140, has its pressure measured in venous air trap chamber 141, and is then returned to the patient. Venous air trap chamber 141 is provided to prevent air from mixing with the blood in venous blood circuit 140. Venous blood circuit 140 is provided with venous air bubble sensor 240a, venous blood sensor 240b, and venous clamp 240c.

[0045] The fluid replacement line 150 is connected to the arterial blood circuit 130 or the venous blood circuit 140 and supplies substitution fluid. In this embodiment, the fluid replacement line 150 is connected to the venous blood circuit 140 and supplies substitution fluid to the venous blood circuit 140. That is, in this embodiment, the blood purification apparatus 1 employs a so-called post-dilution method. Specifically, the fluid replacement line 150 is connected to the venous air trap chamber 141. The substitution fluid that has flowed through the fluid replacement line 150 is supplied into the venous air trap chamber 141. The blood purification apparatus 1 can also employ a so-called pre-dilution method. When the pre-dilution method is employed, the fluid replacement line 150 is connected to the arterial blood circuit 130.

[0046] A replacement fluid pump 151 that delivers a substitution fluid is connected to the replacement fluid line 150. A first connecting line 160 is connected to the drainage line 120. Specifically, the first connecting line 160 is connected to the drainage line 120 downstream of the drainage pump 121. A first measuring bag 165 is connected to the end of the first connecting line 160 opposite the drainage line 120 side, and is capable of temporarily storing the drained fluid and delivering the stored drained fluid. The first measuring bag 165 is a soft bag that does not have any holes for venting air.

[0047] The second connecting conduit 170 is connected to the replacement fluid conduit 150. Specifically, the second connecting conduit 170 is connected to the replacement fluid conduit 150 on the upstream side of the replacement fluid pump 151. The second measuring bag 175 is connected to the end of the second connecting conduit 170 opposite to the replacement fluid conduit 150 side, and is capable of temporarily storing the substitution fluid and discharging the stored substitution fluid. The second measuring bag 175 is a soft bag without any air vent holes.

[0048] A weight measuring unit is connected to the scale 180. The weight measuring unit measures the overall change in weight of the first weighing bag 165 and the second weighing bag 175 attached to the scale 180. In this embodiment, the scale 180 is a load cell. However, the scale 180 is not limited to a load cell and may be a spring balance or the like.

[0049] The syringe pump 190 is connected to the arterial blood circuit 130 via a syringe pump line 191. The syringe pump 190 supplies a medicinal liquid 30 into the arterial blood circuit 130. The medicinal liquid 30 is, for example, an anticoagulant such as heparin or nafamostat.

[0050] The blood pump 131, the fluid supply pump 111, the drainage pump 121, and the replacement fluid pump 151 are driven based on set flow rates. The driving of each of the blood pump 131, the fluid supply pump 111, the drainage pump 121, and the replacement fluid pump 151 is controlled by a control unit. That is, the control unit controls the flow rates of each of the blood pump 131, the fluid supply pump 111, the drainage pump 121, and the replacement fluid pump 151. Figure 2 is a block diagram showing the configuration of the blood purification apparatus 1, including the control unit.

[0051] As shown in FIG. 2, the blood purification apparatus 1 further includes a control unit 90. The control unit 90 receives input of the flow rate setting values for each pump from the input unit 70. The control unit 90 can also control the operation of the blood pump 131, the fluid supply pump 111, the drainage pump 121, and the replacement fluid pump 151 based on the setting values received by the input unit 70. For simplicity's sake, the present disclosure describes the control unit 90 as controlling each pump, but the control unit 90 may also receive information from sensors or the like provided in the blood purification apparatus 1 and control the controlled objects based on that information.

[0052] The control unit 90 is specifically a control board, and includes a processor 91 and a memory 92. The processor 91 executes various programs stored in the memory 92, thereby controlling the operation of the blood pump 131, the fluid supply pump 111, the drainage pump 121, and the replacement fluid pump 151 based on the setting values received by the input unit 70.

[0053] The processor 91 is configured with a CPU, a GPU, etc., and can read and execute programs (such as an OS, a driving program, and a self-diagnostic program, for example) stored in the memory 92. The processor 91 executes various programs read from the memory 92. Specifically, the driving program is a program that controls the flow rate of each pump based on the setting value received by the input unit 70.

[0054] The memory 92 is configured by, for example, a nonvolatile storage device such as a ROM or flash memory, etc. The memory 92 stores a drive program in addition to an OS for realizing basic functions.

[0055] The input unit 70 is not limited to a specific device, but examples include a touch screen in which a touch panel that accepts user touch input and a display are superimposed, and a setting panel in which setting values are input using physical switches.

[0056] The drive program executed by the control unit 90 may be installed via a computer-readable recording medium, or may be installed by downloading it from a server device on a network. In addition, the functions provided by the control unit 90 may be realized by using some of the modules provided by the OS.

[0057] 2 shows an example of a configuration in which the processor 91 executes a program to provide the functions required for the blood purification apparatus 1, but some or all of these provided functions may be implemented using dedicated hardware circuits (e.g., ASIC or FPGA). The configuration of the blood purification apparatus 1 shown in FIG. 2 is an example and is not limited to this configuration.

[0058] Next, the control of each pump by the control unit 90 will be described. When the blood purification device 1 is used for CHDF treatment, for example, the fluid supply pump 111 and the replacement fluid pump 151 are driven simultaneously. The dialysate line 110 and the replacement fluid line 150 are connected via the second connecting line 170, and therefore the fluid supply pump 111 and the replacement fluid pump 151 are two pumps in the connected flow path. When these two pumps are driven simultaneously, the pressure on the inlet side differs depending on the phase difference between the pulsations of the dialysate line 110 and the replacement fluid line 150 at the start of operation.

[0059] 3A and 3B are diagrams illustrating changes in the pressure on the inlet side of the pumps when the phase of the pulsation of the supply fluid pump 111 and the replacement fluid pump 151 changes. In Fig. 3A, the phase difference between the pulsation of the supply fluid pump 111 and the replacement fluid pump 151 at the start of operation is 0°, and the pulsation a of the supply fluid pump 111 and the pulsation b of the replacement fluid pump 151 are in phase. Therefore, the pressure c on the inlet side of the supply fluid pump 111 and the replacement fluid pump 151 changes significantly in accordance with the magnitude of the pulsation a of the supply fluid pump 111 and the pulsation b of the replacement fluid pump 151.

[0060] In FIG. 3(b), the phase difference between the pulsations of the supply fluid pump 111 and the replacement fluid pump 151 at the start of operation is 45°, and the phases of the pulsations a of the supply fluid pump 111 and the pulsations b of the replacement fluid pump 151 are shifted by a quarter cycle. Therefore, the pressure c on the inlet side of the supply fluid pump 111 and the replacement fluid pump 151 is smaller than the change in the inlet side pressure c shown in FIG. 3(a). Furthermore, in FIG. 3(c), the phase difference between the pulsations of the supply fluid pump 111 and the replacement fluid pump 151 at the start of operation is 180°, and the pulsations a of the supply fluid pump 111 and the pulsations b of the replacement fluid pump 151 are out of phase with each other. Therefore, the pressure c on the inlet side of the supply fluid pump 111 and the replacement fluid pump 151 becomes a constant value because the pulsations a of the supply fluid pump 111 and the pulsations b of the replacement fluid pump 151 cancel each other out. In Figures 3(a) to 3(c), the horizontal axis represents time, the vertical axis for the graphs of pulsation a and pulsation b represents flow rate, and the vertical axis for the graph of inlet pressure c represents pressure.

[0061] When the supply fluid pump 111 and the replacement fluid pump 151 are driven simultaneously, the change in pressure c on the inlet side of the supply fluid pump 111 and the replacement fluid pump 151 is not constant but fluctuates due to the phase difference between the pulsations of the supply fluid pump 111 and the replacement fluid pump 151 at the start of operation, as shown in Figures 3(a) to 3(c). If a sensor for detecting the phase is provided so that the phase difference between the pulsations of the two pumps is always the same at the start of operation, the fluctuation in the pressure change on the inlet side of the supply fluid pump 111 and the replacement fluid pump 151 can be suppressed. However, providing a sensor for detecting the phase increases manufacturing costs, and the pumps may be driven by control to align the phases, resulting in unnecessary fluid delivery.

[0062] Therefore, in the blood purification apparatus 1 according to this embodiment, the control unit 90 modulates the flow rates of the supply fluid pump 111 and the replacement fluid pump 151 in an inverse cycle. FIG. 4 shows a graph illustrating a case where the flow rates of the supply fluid pump 111 and the replacement fluid pump 151 are modulated in a rectangular wave form. The horizontal axis in FIG. 4 represents time, and the vertical axis represents the ratio to the set flow rate. In the example shown in FIG. 4, the control unit 90 modulates the flow rate d of the supply fluid pump 111 and the flow rate e of the replacement fluid pump 151 in an inverse cycle. Furthermore, the control unit 90 modulates the flow rate d of the supply fluid pump 111 and the flow rate e of the replacement fluid pump 151 at a rate of ±10% of the set flow rate. The modulation cycle of the flow rate d of the supply fluid pump 111 and the flow rate e of the replacement fluid pump 151 is, for example, 1 second, and modulated in a rectangular wave form.

[0063] Specifically, when the set flow rates of the supply fluid pump 111 and the replacement fluid pump 151 are each set to the same 100 mL / h, the control unit 90 modulates the flow rate d of the supply fluid pump 111 and the flow rate e of the replacement fluid pump 151 by ±10 mL / h in one-second cycles. Note that when the flow rate d of the supply fluid pump 111 is increased by 10 mL / h, the control unit 90 decreases the flow rate e of the replacement fluid pump 151 by 10 mL / h, and when the flow rate d of the supply fluid pump 111 is decreased by 10 mL / h, the control unit 90 increases the flow rate e of the replacement fluid pump 151 by 10 mL / h, thereby controlling the total flow rate of the supply fluid pump 111 and the replacement fluid pump 151 to be the set value.

[0064] This section describes changes in the pressure on the inlet side of the supply fluid pump 111 and the replacement fluid pump 151 when the flow rates of the supply fluid pump 111 and the replacement fluid pump 151 are modulated in an inverse cycle (for example, modulated at a rate of ±10% of the set flow rate). FIG. 5 is a diagram for explaining changes in the pressure on the inlet side of the pumps when the flow rates of the supply fluid pump 111 and the replacement fluid pump 151 are modulated. FIG. 5(a) shows the flow rates modulated in an inverse cycle, with the phase difference between the pulsations of the supply fluid pump 111 and the replacement fluid pump 151 being 0° at the start of operation. The pressure c on the inlet side of the supply fluid pump 111 and the replacement fluid pump 151 changes significantly in accordance with the amplitudes of the pulsations a of the supply fluid pump 111 and the pulsations b of the replacement fluid pump 151, but because the flow rates are modulated in an inverse cycle, the change is smaller than the change in the pressure c on the inlet side shown in FIG. 3(a).

[0065] In FIG. 5(b), the flow rate is modulated in an inverse cycle, and the phase difference between the pulsations of the supply fluid pump 111 and the replacement fluid pump 151 at the start of operation is 45°. The pressure c on the inlet side of the supply fluid pump 111 and the replacement fluid pump 151 changes to the same extent as the change in the inlet side pressure c shown in FIG. 5(a), because the flow rate is modulated in an inverse cycle. Furthermore, in FIG. 5(c), the flow rate is modulated in an inverse cycle, and the phase difference between the pulsations of the supply fluid pump 111 and the replacement fluid pump 151 at the start of operation is 180°. The pressure c on the inlet side of the supply fluid pump 111 and the replacement fluid pump 151 changes to the same extent as the change in the inlet side pressure c shown in FIG. 5(a), because the flow rate is modulated in an inverse cycle.

[0066] As can be seen from FIGS. 5(a) to 5(c), by modulating the flow rates of the supply fluid pump 111 and the replacement fluid pump 151 in an inverse cycle, the change in pressure c on the inlet side of the supply fluid pump 111 and the replacement fluid pump 151 becomes approximately constant, regardless of the phase difference between the pulsations of the supply fluid pump 111 and the replacement fluid pump 151 at the start of operation. In other words, by modulating the flow rates of the supply fluid pump 111 and the replacement fluid pump 151 in an inverse cycle, the control unit 90 can suppress fluctuations in the pressure change on the inlet side of the supply fluid pump 111 and the replacement fluid pump 151. By suppressing fluctuations in the pressure change on the inlet side of the supply fluid pump 111 and the replacement fluid pump 151, the control unit 90 also maintains constant the flow rates of the supply fluid pump 111 and the replacement fluid pump 151. In FIGS. 5(a) to 5(c), the horizontal axis represents time, the vertical axis for the graphs of pulsation a and pulsation b represents flow rate, and the vertical axis for the graph of inlet pressure c represents pressure.

[0067] Furthermore, by suppressing fluctuations in pressure changes on the inlet sides of the supply fluid pump 111 and the replacement fluid pump 151, the control unit 90 can suppress fluctuations in the overall weight change of the first weighing bag 165 and the second weighing bag 175 attached to the scale 180. Suppressing fluctuations in the overall weight change of the first weighing bag 165 and the second weighing bag 175 simplifies the design of the noise removal filter of the control unit 90. In other words, it is no longer necessary to design a noise filter in which the control unit 90 successively adjusts parameters in response to fluctuations in the overall weight change of the first weighing bag 165 and the second weighing bag 175.

[0068] In Fig. 4, the control unit 90 varies the flow rate d of the supply fluid pump 111 and the flow rate e of the replacement fluid pump 151 in a rectangular wave pattern, but this is not limited to this. Fig. 6 shows graphs in which the flow rate d of the supply fluid pump 111 and the flow rate e of the replacement fluid pump 151 are modulated in a triangular wave pattern or a sinusoidal wave pattern. In the graph shown in Fig. 6(a), the flow rate d of the supply fluid pump 111 and the flow rate e of the replacement fluid pump 151 are modulated in a triangular wave pattern with an inverse cycle. In the graph shown in Fig. 6(b), the flow rate d of the supply fluid pump 111 and the flow rate e of the replacement fluid pump 151 are modulated in a sinusoidal wave pattern with an inverse cycle. In Figs. 6(a) and 6(b), the horizontal axis represents time, and the vertical axis represents the ratio to the set flow rate.

[0069] In the above-described embodiment, the set flow rate of the fluid supply pump 111 is the same as the set flow rate of the replacement fluid pump 151. However, if the set flow rate of the fluid supply pump 111 is different from the set flow rate of the replacement fluid pump 151, and the flow rates of the fluid supply pump 111 and the replacement fluid pump 151 are modulated by the same percentage (for example, ±10%) of the set flow rate, the total flow rate of the fluid supply pump 111 and the replacement fluid pump 151 may not match the sum of the set flow rates of the two pumps.

[0070] Specifically, if the set flow rate of the fluid supply pump 111 is 200 mL / h and the set flow rate of the replacement fluid pump 151 is 100 mL / h, when the control unit 90 modulates the flow rate of the fluid supply pump 111 by +10%, the flow rate becomes 220 mL / h, but when the control unit 90 modulates the flow rate of the replacement fluid pump 151 by -10%, the flow rate becomes 90 mL / h. Therefore, the total flow rate of the fluid supply pump 111 and the replacement fluid pump 151 is 220 + 90 = 310 mL / h, which is greater than the total set flow rate of the two pumps, 300 mL / h. If the total flow rate of the fluid supply pump 111 and the replacement fluid pump 151 is greater than the sum of the set flow rates of the two pumps, the patient may become over-hydrated. Conversely, if the total flow rate is less than the sum of the set flow rates of the two pumps, the patient may become over-hydrated.

[0071] Therefore, the control unit 90 modulates the flow rate of the pump with the higher or lower set flow rate by ±10% to modulate the flow rate of the pump with the lower or higher set flow rate so that the total flow rate of the two pumps becomes the sum of the set flow rates. In other words, the control unit 90 sets the flow rate to be modulated for each pump so that the total flow rate of the two pumps becomes the sum of the set flow rates of each pump. In this way, even if the set flow rates of the two pumps are different, the control unit 90 can control the total flow rate of the two pumps to the same total flow rate after modulation.

[0072] Specifically, if the set flow rate of the supply fluid pump 111 is 200 mL / h and the set flow rate of the replacement fluid pump 151 is 100 mL / h, the control unit 90 modulates the flow rate of the supply fluid pump 111, which has a higher set flow rate, by +10%, resulting in 220 mL / h. Therefore, rather than modulating the flow rate of the replacement fluid pump 151, which has a lower set flow rate, by -10%, the control unit 90 sets the flow rate to 80 mL / h so that the total flow rate of the two pumps matches the total set flow rate. As a result, the total flow rate of the supply fluid pump 111 and the replacement fluid pump 151 is 220 + 80 = 300 mL / h, which matches the total set flow rate of the two pumps, 300 mL / h.

[0073] Furthermore, if the set flow rate of the supply fluid pump 111 is 200 mL / h and the set flow rate of the replacement fluid pump 151 is 100 mL / h, the control unit 90 modulates the flow rate of the replacement fluid pump 151, which has a lower set flow rate, by -10%, resulting in 90 mL / h. Therefore, rather than modulating the flow rate of the supply fluid pump 111, which has a higher set flow rate, by +10%, the control unit 90 sets the total flow rate of the two pumps to 210 mL / h so that it matches the total set flow rate of the two pumps. As a result, the total flow rate of the supply fluid pump 111 and the replacement fluid pump 151 is 210 + 90 = 300 mL / h, which matches the total set flow rate of the two pumps, 300 mL / h.

[0074] In the above-described embodiment, the flow rates of the fluid supply pump 111 and the fluid replacement pump 151 are modulated when the blood purification apparatus 1 is used for CHDF treatment. However, the blood purification apparatus 1 is not limited to use in CHDF treatment. For example, when the blood purification apparatus 1 is used for CHD treatment, the fluid replacement pump 151 is not driven, and only the fluid supply pump 111 and the fluid drainage pump 121 are driven, so the control unit 90 modulates the flow rates of the fluid supply pump 111 and the fluid drainage pump 121 in a reverse cycle. On the other hand, when the blood purification apparatus 1 is used for CHF treatment, the fluid supply pump 111 is not driven, and only the fluid replacement pump 151 and the fluid drainage pump 121 are driven, so the control unit 90 modulates the flow rates of the fluid replacement pump 151 and the fluid drainage pump 121 in a reverse cycle.

[0075] The blood purification apparatus 1 modulates different pumps depending on the treatment method used. Therefore, when the input unit 70 receives information about the treatment method using the blood purification apparatus 1, the control unit 90 identifies two pumps that are currently being driven from among the fluid supply pump 111, the drainage pump 121, and the replacement fluid pump 151. The control unit 90 then modulates the flow rates of the identified two pumps in reverse cycles. As a result, the control unit 90 modulates the flow rates of the two pumps currently being driven from among the fluid supply pump 111, the drainage pump 121, and the replacement fluid pump 151 in reverse cycles, thereby suppressing fluctuations in pressure changes on the inlet sides of the two pumps without adding any sensors.

[0076] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0077] 1 Blood purification device, 2 Blood leakage sensor, 20 Substitution fluid, 30 Drug solution, 70 Input unit, 90 Control unit, 91 Processor, 92 Memory, 100 Blood purifier, 101 Dialysis fluid inlet, 102 Drainage outlet, 103 Blood inlet, 104 Blood outlet, 110 Dialysis fluid line, 111 Supply pump, 120 Drainage line, 121 Drainage pump, 122 Filtration pressure sensor, 130 Arterial blood circuit, 131 Blood pump, 132 Arterial air trap chamber, 133 Inlet pressure sensor, 136 Substitution fluid line, 138 Airless monitor, 139 Venous blood circulation pressure sensor, 140 Venous blood circuit, 141 Venous air trap chamber, 142 Venous circuit pressure sensor, 150 Infusion fluid line, 151 Infusion fluid pump, 160 First connecting line, 165 First weighing bag, 170 second connecting line, 175 second weighing bag, 180 scale, 185 supply source, 190 syringe pump, 191 syringe pump line.

Claims

1. Blood purifier and an arterial blood circuit connected to the blood purifier for allowing blood to flow into the blood purifier; a venous blood circuit connected to the blood purifier for allowing blood to flow out of the blood purifier; a fluid replacement line connected to the arterial blood circuit or the venous blood circuit for supplying a replacement fluid; a dialysate line for supplying dialysate to the blood purifier; a drainage pipe through which the drainage liquid discharged from the blood purifier flows; a blood pump provided in the arterial blood circuit for pumping blood; a supply pump provided in the dialysis fluid line for pumping out the dialysis fluid; a drainage pump provided in the drainage pipeline for pumping out the drainage liquid; a replacement fluid pump provided in the replacement fluid line and configured to pump out the replacement fluid; a control unit that controls the flow rates of the fluid supply pump, the drainage pump, and the replacement fluid pump; The control unit modulates the flow rates of two pumps being driven among the fluid supply pump, the fluid drainage pump, and the fluid replacement pump in an inverse cycle.

2. 2. The blood purification apparatus according to claim 1, wherein the control unit sets the flow rates to be modulated by each of the two pumps so that the total flow rate of the two pumps is equal to the sum of the set flow rates of the respective pumps.

3. The blood purification apparatus according to claim 2 , wherein when the set flow rates of the two pumps are the same, the control unit modulates the flow rates of the two pumps at the same rate and in an inverse cycle to the set flow rates.

4. The blood purification apparatus according to claim 1 , wherein the control unit modulates the flow rates of the two pumps in a rectangular wave pattern with opposite periods.

5. The blood purification apparatus according to claim 1 , wherein the control unit modulates the flow rates of the two pumps in a triangular wave pattern with opposite periods.

6. The blood purification apparatus according to claim 1 , wherein the control unit modulates the flow rates of the two pumps in a sinusoidal manner with opposite cycles.

7. The blood purification apparatus according to any one of claims 1 to 6, wherein the control unit drives the flow rates of the fluid supply pump and the fluid replacement pump, and modulates the flow rate of the fluid supply pump and the flow rate of the fluid replacement pump in inverse cycles.

8. The blood purification apparatus according to any one of claims 1 to 6, wherein the control unit drives the flow rates of the supply pump and the drainage pump, and modulates the flow rate of the supply pump and the flow rate of the drainage pump in inverse cycles.

9. The blood purification apparatus according to any one of claims 1 to 6, wherein the control unit drives the flow rates of the fluid replacement pump and the drainage pump, and modulates the flow rate of the fluid replacement pump and the flow rate of the drainage pump in inverse cycles.

10. a control unit for controlling the flow rates of the supply pump, the drain pump, and the replacement fluid pump, the control unit controlling the flow rates of the supply pump, the drain pump, and the replacement fluid pump, Identifying two pumps that are being driven among the fluid supply pump, the fluid discharge pump, and the fluid replacement pump; and modulating the flow rates of the two identified pumps at opposite cycles.

11. a control unit for controlling the flow rates of the supply pump, the drain pump, and the replacement fluid pump, the control unit comprising: a blood purifier; an arterial blood circuit connected to the blood purifier for introducing blood into the blood purifier; a venous blood circuit connected to the blood purifier for discharging blood from the blood purifier; a replacement fluid line connected to the arterial blood circuit or the venous blood circuit for supplying replacement fluid; a dialysate line for supplying dialysate to the blood purifier; a drainage line for draining the drained fluid discharged from the blood purifier; a blood pump provided in the arterial blood circuit for pumping blood; a supply pump provided in the dialysate line for pumping the dialysate; a drainage pump provided in the drainage line for pumping the drained fluid; a replacement fluid pump provided in the replacement fluid line for pumping the replacement fluid; The program Identifying two pumps that are being driven among the fluid supply pump, the fluid discharge pump, and the fluid replacement pump; and modulating the flow rates of the two identified pumps at opposite cycles.

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