Blood purification device and control method of liquid feed pump

Abstract

To provide a blood purification device and a drive control method of a liquid feed pump capable of shortening a time before a flow rate of a liquid feed pump reaches a level near a target flow rate, and capable of suppressing flow rate fluctuation by feedback control.SOLUTION: A blood purification device includes: a dialysate solution circuit 41 for supplying a dialysate solution to a dialyzer 10 and discharging a dialysate solution from the dialyzer 10; a liquid supply pump 63 disposed in the dialysate solution circuit 41; and a control part 22 for executing a liquid supply pump drive control operation for controlling the liquid supply pump 63 so that the flow rate of the liquid supply pump 63 becomes the target flow rate. In the liquid supply pump drive control operation, feed-forward control is executed, and on condition that a predetermined time has elapsed, feed-forward control is switched to feed-back control.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a blood purification apparatus and a method for controlling a fluid delivery pump. [Background technology]

[0002] Conventionally, a blood purification device controls the drive of a fluid delivery pump by feedback control (see Patent Document 1). This blood purification device includes a blood purifier, a dialysis fluid line that supplies dialysis fluid to the blood purifier, a drainage line through which waste fluid is discharged from the blood purifier, a fluid delivery pump (dialysis fluid pump) disposed in the dialysis fluid line, and a water balance detection unit that detects the water balance (amount of water removed) between the dialysis fluid and the waste fluid, and controls the drive of the fluid delivery pump by feeding back the detection results detected by the water balance detection unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020-137190 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional blood purification device, it takes time for the flow rate of the fluid delivery pump to reach a target flow rate, and the flow rate of the dialysis fluid may fluctuate due to the feedback control of the fluid delivery pump. If the flow rate fluctuates, it may cause a disturbance to the feedback control of other actuators (e.g., heaters, etc.).

[0005] Therefore, an object of the present invention is to provide a blood purification device and a method for controlling the drive of a fluid delivery pump, which can shorten the time it takes for the flow rate of the fluid delivery pump to reach near a target flow rate and suppress flow rate fluctuations due to feedback control. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the present invention provides a blood purification device that performs blood purification therapy via a blood purifier that purifies the blood of a patient, comprising a dialysis fluid circuit that supplies dialysis fluid to the blood purifier and discharges the dialysis fluid from the blood purifier, a fluid delivery pump that is disposed in the dialysis fluid circuit and delivers dialysis fluid in the dialysis fluid circuit, a drive control unit that executes a drive control operation that controls the fluid delivery pump so that the flow rate of the fluid delivery pump becomes a target flow rate, and a flow rate detection unit that detects the flow rate of the fluid delivery pump, wherein in the drive control operation, feedforward control is performed that is not based on the detection value of the flow rate detection unit, and when a predetermined time has passed or a predetermined flow rate has been reached, the blood purification device switches from the feedforward control to feedback control based on the detection value of the flow rate detection unit.

[0007] In addition, in order to achieve the above-mentioned object, the present invention provides a method for controlling a fluid delivery pump arranged in a dialysis fluid circuit of a blood purification device, which controls the flow rate of the fluid delivery pump to a target flow rate, and which performs feedforward control that is not based on a detection value of a flow detection unit that detects the flow rate of the fluid delivery pump, and switches from the feedforward control to feedback control based on the detection value of the flow detection unit, on the condition that a predetermined time has passed or a predetermined flow rate has been reached. Effect of the Invention

[0008] According to the present invention, it is possible to provide a blood purification apparatus and a method for controlling a fluid delivery pump, which can shorten the time it takes for the flow rate of the fluid delivery pump to reach near a target flow rate, and can suppress flow rate fluctuations due to feedback control. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing the structure of a blood purification device according to one embodiment of the present invention. [Diagram 2] 11 is a flowchart showing the first half of a calibration operation. [Diagram 3]13 is a flowchart showing the latter half of the calibration operation. [Figure 4] 11 is a graph showing an example of a command value and a flow rate versus time in a liquid supply pump drive control operation and a liquid discharge pump drive control operation. [Diagram 5] 13 is a flowchart showing a supply pump drive control operation. [Figure 6] 11 is a flowchart showing a drainage pump drive control operation. [Figure 7] 10 is a flowchart showing a modified example of the supply pump drive control operation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a blood purification device according to one embodiment of the present invention will be described with reference to the attached drawings. This blood purification device is a medical device that performs blood purification therapy by purifying the patient's blood via a dialyzer. In particular, this blood purification device uses feedforward control and feedback control to quickly reach a target flow rate and to enable stable flow rate control.

[0011] (Blood purification device configuration) As shown in Fig. 1, the blood purification device 1 includes a dialyzer 10 that purifies the blood of a patient C, an extracorporeal circulation unit 11 that circulates the blood of the patient C through the dialyzer 10, and a dialysate supply / drain unit 12 that is connected to the dialyzer 10 and supplies dialysate to the dialyzer 10 and drains the dialysate from the dialyzer 10. The extracorporeal circulation unit 11 and the dialysate supply / drain unit 12 are configured separately, and the dialyzer 10 is detachably attached to the extracorporeal circulation unit 11 via a fixing jig 13. The dialyzer 10 is an example of a blood purifier.

[0012] The dialyzer 10 has a blood purification membrane (hollow fiber type hemodialysis membrane, or hemodiafiltration membrane, flat membrane type hemodialysis membrane, or hemofiltration membrane) built in. The dialyzer 10 has a blood inlet 10a for introducing blood and a blood outlet 10b for discharging the introduced blood, as well as a dialysate inlet 10c for introducing dialysate and a dialysate outlet 10d for discharging the introduced dialysate. The dialyzer 10 purifies blood by bringing the blood and the dialysate into contact with each other through the blood purification membrane. The dialyzer 10 also controls the supply and discharge of the dialysate supply and discharge unit 12 to remove water from the blood.

[0013] The extracorporeal circulation unit 11 includes an extracorporeal circulation circuit 21 that circulates the blood of the patient C through the dialyzer 10, and a control unit 22. The control unit 22 will be described later.

[0014] The extracorporeal circuit 21 includes an arterial blood flow path 31 connected to the blood inlet 10a of the dialyzer 10 and leading blood taken from the blood vessel of the patient C to the dialyzer 10, a venous blood flow path 32 connected to the blood outlet 10b of the dialyzer 10 and leading blood discharged from the dialyzer 10 back to the blood vessel of the patient C, and a blood pump 34 disposed in the arterial blood flow path 31 and circulating the blood. By driving the blood pump 34, blood from the patient C is led to the dialyzer 10 via the arterial blood flow path 31, and after the blood is purified by the dialyzer 10, it is returned to the patient C via the venous blood flow path 32. This purifies the blood of the patient C.

[0015] (Configuration of dialysis fluid supply and drainage unit) The dialysis fluid supply / drainage unit 12 has a dialysis fluid circuit 41 that supplies dialysis fluid to the dialyzer 10 and discharges dialysis fluid from the dialyzer 10, and a dialysis fluid supply / drainage unit side control section .

[0016] The dialysate circuit 41 includes a dialysate preparation section 51 for purifying the dialysate, a dialysate supply flow path 52 connected to the dialysate inlet 10c of the dialyzer 10 and for supplying the dialysate purified by the dialysate preparation section 51 to the dialyzer 10, a dialysate discharge flow path 53 connected to the dialysate outlet 10d of the dialyzer 10 and for recovering and discharging the used dialysate from the dialyzer 10, and a first bypass flow path 54 connected to the dialysate supply flow path 52 and the dialysate discharge flow path 53 before and after the dialyzer 10 and for communicating between the dialysate supply flow path 52 and the dialysate discharge flow path 53 without passing through the dialyzer 10.

[0017] The dialysis fluid preparation section 51 prepares the dialysis fluid from the supplied pure water and a dialysate consisting of a concentrated solution or a powder. The pure water supplied to the dialysis fluid preparation section 51 may be supplied from a pure water production section mounted in the dialysis fluid supply / drainage unit 12, or may be supplied from a pure water production device provided outside the dialysis fluid supply / drainage unit 12. The dialysis fluid preparation section 51 may also be omitted, and for example, the dialysis fluid may be supplied to the dialysis fluid supply / drainage unit 12 from an external dialysis fluid supply device or the like.

[0018] In the dialysis fluid supply flow path 52, from the upstream side, a supply fluid pump 63, a supply side control flow meter 64, a supply side protection flow meter 65, and a first solenoid valve 66 are arranged. The supply fluid pump 63 is a fluid delivery pump that delivers the dialysis fluid in the dialysis fluid supply flow path 52. By driving the supply fluid pump 63, the dialysis fluid is supplied to the dialyzer 10. The supply fluid pump 63 is an example of a first fluid delivery pump.

[0019] The supply-side control flowmeter 64 and the supply-side protection flowmeter 65 are disposed downstream of the supply fluid pump 63 and are flowmeters that detect the flow rate of the supply fluid pump 63 (i.e., the flow rate of the dialysis fluid). The supply-side control flowmeter 64 is a control flowmeter that detects the flow rate of the supply fluid pump 63 for controlling the supply fluid pump 63. On the other hand, the supply-side protection flowmeter 65 is a protection flowmeter that ensures that the supply-side control flowmeter 64 and its detection value are normal. The supply-side control flowmeter 64 is an example of a flow rate detection unit.

[0020] The first solenoid valve 66 is disposed downstream of the connection position to which the first bypass flow path 54 is connected, and is one of the solenoid valves for switching the flow path from the flow path passing through the dialyzer 10 to the first bypass flow path 54.

[0021] In the dialysate discharge flow path 53, from the upstream side, a second solenoid valve 71, a drainage pump 72, a drain-side control flow meter 73, and a drain-side protection flow meter 74 are disposed. In addition, in the dialysate discharge flow path 53, a second bypass flow path 75 connected before and after the drainage pump 72 is disposed.

[0022] The second solenoid valve 71 is disposed upstream of the connection position to which the first bypass flow path 54 is connected, and is one of the solenoid valves for switching the flow path from the flow path passing through the dialyzer 10 to the first bypass flow path 54.

[0023] The drainage pump 72 is a fluid delivery pump that delivers the dialysis fluid from the dialysis fluid discharge flow path 53. The dialysis fluid is discharged from the dialyzer 10 by driving the drainage pump 72. The amount of blood removed in the dialyzer 10 is controlled by controlling the supply pump 63 and the drainage pump 72 to adjust the flow rate of the supply pump 63 and the flow rate of the drainage pump 72. The drainage pump 72 is an example of a second fluid delivery pump.

[0024] The discharge side control flowmeter 73 and the discharge side protection flowmeter 74 are disposed downstream of the drainage pump 72 and are flowmeters that detect the flow rate of the drainage pump 72 (i.e., the flow rate of the dialysis fluid). The discharge side control flowmeter 73 is a control flowmeter that detects the flow rate of the drainage pump 72 to control the drainage pump 72. On the other hand, the discharge side protection flowmeter 74 is a protection flowmeter that ensures that the discharge side control flowmeter 73 and its detection value are normal. The discharge side control flowmeter 73 is an example of a flow rate detection unit.

[0025] The second bypass flow path 75 is a flow path for releasing the pressure of the dialysate discharge flow path 53, and is connected to the dialysate discharge flow path 53 before and after the drainage pump 72. The second bypass flow path 75 is provided with a third solenoid valve 76 for switching the flow path state between a communication state in which the second bypass flow path 75 communicates with the dialysate discharge flow path 53 and a non-communication state in which the second bypass flow path 75 does not communicate with the dialysate discharge flow path 53. By opening the third solenoid valve 76, the dialysate discharge flow path 53 and the second bypass flow path 75 are communicated with each other, the pressure of the dialysate circuit 41 is released, and the dialysate discharge flow path 53 is put into a pressure-released state. On the other hand, by closing the third solenoid valve 76, the communication between the dialysate discharge flow path 53 and the second bypass flow path 75 is cut off, and the dialysate discharge flow path 53 is returned to a normal state (non-pressure-released state).

[0026] A fourth solenoid valve 55 is disposed in the first bypass flow path 54. By opening the fourth solenoid valve 55 and closing the first solenoid valve 66 and the second solenoid valve 71, the flow path is switched from the flow path passing through the dialyzer 10 to the first bypass flow path 54. On the other hand, by closing the fourth solenoid valve 55 and opening the first solenoid valve 66 and the second solenoid valve 71, the flow path is switched from the first bypass flow path 54 to the flow path passing through the dialyzer 10.

[0027] The dialysis fluid supply / drainage unit side control section 42 communicates with the control section 22 of the extracorporeal circulation unit 11, and controls the fluid supply pump 63, the fluid drainage pump 72, and the solenoid valves 55, 66, 71, 76 according to commands from the control section 22. The dialysis fluid supply / drainage unit side control section 42 is realized by appropriately combining a calculation element such as a CPU, a memory, software, an interface, a communication unit, and the like.

[0028] (Control unit and its control) Here, the control unit 22 of the extracorporeal circulation unit 11 and the control by the control unit 22 will be described with reference to Figs. 1 to 6. The control unit 22 controls the blood pump 34, and communicates with the dialysis fluid supply / drainage unit side control unit 42 to control the supply pump 63, the drain pump 72, and the solenoid valves 55, 66, 71, and 76 via the dialysis fluid supply / drainage unit side control unit 42. The control unit 22 also receives detection values ​​of the flow meters 64, 65, 73, and 74 via the dialysis fluid supply / drainage unit side control unit 42. In particular, the control unit 22 executes a calibration operation, a supply pump drive control operation, and a drain pump drive control operation. The control unit 22 is realized by appropriately combining a calculation element such as a CPU, a memory, software, an interface, a communication unit, and the like. The control unit 22 is an example of a drive control unit and a calibration unit, and the supply pump drive control operation and the drain pump drive control operation are examples of a drive control operation and a drive control method for a fluid delivery pump.

[0029] The calibration operation is an operation for obtaining a proportional relational expression between a command value and a flow rate used in feedforward control, in which command values ​​at two different flow rates are obtained and a proportional relational expression is calculated based on the command values. The proportional relational expression is an example of calibration information that relates the command values ​​for the pumps 63 and 72 to the flow rates. In this embodiment, 300 mL / min and 500 mL / min are used as an example of the two flow rates.

[0030] In the present embodiment, for example, a DA value is used as the command value. The DA value is a command value output from the control unit 22 to each pump (supply pump 63, drainage pump 72, etc.) via the dialysis fluid supply / drainage unit side control unit 42. Strictly speaking, the DA value is output as a 16-bit digital signal from the microcomputer of the control unit 22 to a DA converter via the microcomputer of the dialysis fluid supply / drainage unit side control unit 42, and is converted into a corresponding command voltage in the DA converter. The converted command voltage is input to each pump 63, 72. The pumps 63, 72 are driven by the input command voltage. Note that the control unit 22 or the dialysis fluid supply / drainage unit side control unit 42 may have a DA converter and convert the DA value into a command voltage, or the blood purification device 1 may have a DA converter separate from the control unit 22 and the dialysis fluid supply / drainage unit side control unit 42.

[0031] 2 and 3 are flow charts showing the calibration operation. As shown in Fig. 2, in the calibration operation, first, the first solenoid valve 66, the second solenoid valve 71 and the third solenoid valve 76 are closed (S1), and the fourth solenoid valve 55 is opened (S2). As a result, the flow path is switched from the flow path passing through the dialyzer 10 to the first bypass flow path 54, and the dialysate discharge flow path 53 is put into a non-pressure release state.

[0032] Thereafter, the supply pump 63 and the drainage pump 72 are driven by feedback control with a target flow rate of 300 mL / min (S3). This creates a state in which the dialysis fluid is pumped at a flow rate of 300 mL / min. If the flow rate detected by each of the control flow meters 64, 73 is not within a range close to 300 mL / min (for example, within a range of ±2) for a predetermined number of consecutive seconds (S4: No) and a predetermined time has passed (S5: Yes), it is determined that there is an abnormality in each of the pumps 63, 72 or each of the control flow meters 64, 73, an alarm is output (S6), and this operation is terminated. In other words, if the flow rates of the supply pump 63 and the drainage pump 72 do not reach the target flow rates by feedback control, it is determined that there is an abnormality in each of the pumps 63, 72 or each of the control flow meters 64, 73. The feedback control is a control in which the detected values ​​(flow rates) of the control flow meters 64, 73 are periodically fed back to change the command values, and the pumps 63, 72 are driven by the changed command values.

[0033] On the other hand, when the flow rates detected by the control flow meters 64, 73 are within the range of 300 mL / min for a predetermined number of consecutive seconds due to the implementation of feedback control (S4: Yes), the command values ​​of the supply pump 63 and the drainage pump 72 are recorded (S7). In this way, the command values ​​of the pumps 63, 72 when the flow rate is 300 mL / min are obtained.

[0034] Thereafter, the supply pump 63 and the drain pump 72 are driven by feedback control with a target flow rate of 500 mL / min (S8). This creates a state in which the dialysis fluid is pumped at a flow rate of 500 mL / min. If, as a result of implementing feedback control, the flow rates detected by the control flow meters 64, 73 are not within a range close to 500 mL / min (e.g., a range of ±2) for a predetermined number of consecutive seconds (S9: No) and a predetermined time has passed (S10: Yes), it is determined that there is an abnormality in the pumps 63, 72 or the control flow meters 64, 73, an alarm is output (S11), and this operation ends.

[0035] On the other hand, when the flow rate detected by each of the control flow meters 64, 73 is within the range of 500 mL / min for a predetermined number of consecutive seconds due to the implementation of feedback control (S9: Yes), the command values ​​of the supply pump 63 and the drainage pump 72 are recorded (S12). In this way, the command values ​​of each of the pumps 63, 72 when the flow rate is 500 mL / min are obtained.

[0036] After the first command value recording process (S2 to S12) is completed, a second command value for confirmation is recorded (S13 to S22) as shown in Fig. 3. That is, as in the first recording process, first, the supply pump 63 and the drainage pump 72 are driven by feedback control with a target flow rate of 300 mL / min (S13). When the flow rate detected by each of the control flow meters 64, 73 is not within the vicinity of 300 mL / min for a predetermined number of consecutive seconds (S14: No) and a predetermined time has passed (S15: Yes) due to the implementation of the feedback control, it is determined that there is an abnormality in each of the pumps 63, 72 or each of the control flow meters 64, 73, an alarm is output (S16), and this operation ends.

[0037] On the other hand, if feedback control is implemented so that the flow rates detected by each control flow meter 64, 73 are within the range of 300 mL / min for a predetermined number of consecutive seconds (S14: Yes), the command values ​​of the supply pump 63 and the drainage pump 72 are recorded (S17).

[0038] Thereafter, the supply pump 63 and the drain pump 72 are driven by feedback control with a target flow rate of 500 mL / min (S18). If the flow rate detected by each control flow meter 64, 73 is not within the vicinity of 500 mL / min for a predetermined number of consecutive seconds (S19: No) and a predetermined time has passed (S20: Yes), it is determined that there is an abnormality in each pump 63, 72 or each control flow meter 64, 73, an alarm is output (S21), and this operation is terminated. On the other hand, if the flow rate detected by each control flow meter 64, 73 is within the vicinity of 500 mL / min for a predetermined number of consecutive seconds (S18: Yes) as a result of feedback control, the command values ​​of the supply pump 63 and the drain pump 72 are recorded (S22).

[0039] After completing the two recording processes, it is determined whether or not the command value recorded the first time and the command value recorded the second time for each flow rate (300 mL / min and 500 mL / min) of each pump 63, 72 match (S23). If it is determined that the first command value and the second command value do not match (S23: No), an alarm is output (S24) and this operation is terminated. On the other hand, if it is determined that the first command value and the second command value match (S23: Yes), a proportional relational equation between the command value and the flow rate is calculated based on the second command value (S25). That is, a proportional relational equation between the command value and the flow rate in the liquid supply pump 63 is calculated based on the command value of the liquid supply pump 63 when the flow rate is 300 mL / min and the command value of the liquid supply pump 63 when the flow rate is 500 mL / min, which are recorded by the second recording process. In addition, based on the command value of the drainage pump 72 when the flow rate is 300 mL / min and the command value of the drainage pump 72 when the flow rate is 500 mL / min, which were recorded in the second recording process, a proportional relationship equation between the command value and the flow rate in the drainage pump 72 is calculated.

[0040] After the proportional relational expression of each pump 63, 72 is calculated, the presence or absence of an abnormality of each pump 63, 72 or each control flow meter 64, 73 is judged based on whether or not the proportional relational expression (mainly the slope) of each pump 63, 72 is within a predetermined range. That is, the presence or absence of an abnormality of each pump 63, 72 or each control flow meter 64, 73 is judged based on whether the calculated proportional relational expression of each pump 63, 72 is correct or not. If it is judged that the proportional relational expression of each pump 63, 72 exceeds the predetermined range and is an abnormal value (S26: No), it is judged that there is an abnormality in each pump 63, 72 or each control flow meter 64, 73, and an alarm is output (S27). On the other hand, if it is judged that the proportional relational expression of each pump 63, 72 is within the predetermined range and is a normal value (S26: Yes), it is judged that there is no abnormality in each pump 63, 72 or each control flow meter 64, 73, and this operation is terminated. In this manner, in this embodiment, by performing an abnormality determination for each of the pumps 63, 72 or each of the control flow meters 64, 73 during the calibration operation for obtaining the proportional relational expression, it is possible to easily detect an abnormality.

[0041] The liquid supply pump drive control operation is an operation for controlling the drive of the liquid supply pump 63 so that the flow rate of the liquid supply pump 63 becomes the target flow rate. As shown in FIG. 4, the feedforward control is performed until a predetermined time has elapsed when the target flow rate is estimated to be reached by the feedforward control (FF control) not based on the detection value of the supply side control flow meter 64, and after the predetermined time has elapsed, the feedforward control is switched to the feedback control (FB control) based on the detection value of the supply side control flow meter 64. The feedforward control is a control for driving the pumps 63, 72 by a constant command value, not based on the detection value of the supply side control flow meter 64. In the liquid supply pump drive control operation, a command value for the target flow rate calculated based on the proportional relational expression obtained in the calibration operation is used as a command value for the feedforward control. In this embodiment, it is estimated that the flow rate of the liquid supply pump 63 will reach the target flow rate if the liquid supply pump 63 is driven for 10 seconds by the feedforward control based on the command value, so the above-mentioned "predetermined time when the target flow rate is estimated to be reached by the feedforward control" is set to 10 seconds.

[0042] Fig. 5 is a flowchart showing the liquid supply pump drive control operation. As shown in Fig. 5, in the liquid supply pump drive control operation, first, a command value for a target flow rate is calculated based on the proportional relational expression of the liquid supply pump 63 acquired in the calibration operation (S31). Then, the liquid supply pump 63 is driven by feedforward control using the calculated command value (S32). When the above-mentioned predetermined time (10 seconds) has elapsed since starting to drive the liquid supply pump 63 by feedforward control (S33: Yes), the drive control of the liquid supply pump 63 is switched from feedforward control to feedback control (S34). This ends the operation.

[0043] The drainage pump drive control operation is an operation for controlling the drive of the drainage pump 72 so that the flow rate of the drainage pump 72 becomes the target flow rate. As shown in FIG. 4, the feedforward control is performed until a predetermined time has elapsed during which the target flow rate is estimated to be reached by feedforward control not based on the detection value of the discharge-side control flow meter 73, and after the predetermined time has elapsed, the feedforward control is switched to feedback control based on the detection value of the discharge-side control flow meter 73. In the drainage pump drive control operation, a command value for the target flow rate calculated based on the proportional relational expression obtained in the calibration operation is used as a command value for the feedforward control. In this embodiment, it is estimated that the flow rate of the drainage pump 72 will reach the target flow rate if the drainage pump 72 is driven for 10 seconds by feedforward control based on the command value, so the above-mentioned "predetermined time during which the target flow rate is estimated to be reached by feedforward control" is set to 10 seconds.

[0044] Fig. 6 is a flow chart showing the drainage pump drive control operation. As shown in Fig. 6, in the drainage pump drive control operation, first, a command value for a target flow rate is calculated based on the proportional relational expression of the drainage pump 72 acquired in the calibration operation (S41). Then, the drainage pump 72 is driven by feedforward control using the calculated command value (S42). When the above-mentioned predetermined time (10 seconds) has elapsed since starting to drive the drainage pump 72 by feedforward control (S43: Yes), the drive control of the drainage pump 72 is switched from feedforward control to feedback control (S44). This ends the operation.

[0045] The blood purification device 1 executes a startup process, a treatment preparation process, a patient needle insertion and blood removal process, a treatment process, a treatment interruption process, a patient needle removal and blood return process, a drainage process, a cleaning and disinfection process, a standby process, and an adjustment process. Calibration operations are executed during self-diagnosis in the startup process and in the adjustment process.

[0046] On the other hand, the supply pump drive control operation is executed when the supply pump 63 is started in the start-up step, when the supply pump 63 is restored in the treatment interruption step, and when the target flow rate of the supply pump 63 is changed in the preparation step, the patient needle removal / blood return step, the treatment step, and the patient needle removal / blood return step. That is, the control unit 22 executes the supply pump drive control operation as the control operation of the supply pump 63 when the supply pump 63 is started (when the supply pump 63 is started), when the supply pump 63 is restored (when the supply pump 63 is restored), and when the target flow rate of the supply pump 63 is changed (when the target flow rate of the supply pump 63 is changed). In this way, when the supply pump 63 is started or restored, or when the target flow rate is changed, by performing the supply pump drive control operation of switching from feedforward control to feedback control, it is possible to shorten the time until the flow rate of the supply pump 63 reaches the vicinity of the target flow rate, and to suppress flow rate fluctuations due to feedback control.

[0047] The drainage pump drive control operation is executed when the third solenoid valve 76 in the open state is closed in the start-up process, the treatment preparation process, the needle insertion and blood removal process, the treatment process, the treatment interruption process, the needle removal and blood return process, the cleaning and disinfection process, the standby process, and the adjustment process. That is, the drainage pump drive control operation is executed when the third solenoid valve 76 is closed to disconnect the dialysate discharge flow path 53 from the second bypass flow path 75 from a state in which the third solenoid valve 76 is opened to connect the dialysate discharge flow path 53 and the second bypass flow path 75. That is, the control unit 22 executes the drainage pump drive control operation as the control operation of the drainage pump 72 when the second bypass flow path 75 is switched from a connected state to a disconnected state by the third solenoid valve 76 (when the third solenoid valve 76 switches from a connected state to a disconnected state). In this way, by performing a drainage pump drive control operation in which feedforward control is performed and then switched to feedback control when switching communication of the second bypass flow path 75, it is possible to drive the drainage pump 72 without being affected by a detection error of the discharge-side control flow meter 73 that occurs when switching communication of the second bypass flow path 75. Note that a configuration may be adopted in which feedforward control is performed when the third solenoid valve 76 is opened, and the feedforward control is switched to feedback control when the third solenoid valve 76 is closed.

[0048] (Actions and Effects of the Embodiments) As described above, according to the configuration of the above embodiment, the time required for the flow rate of the pumps 63, 72 to reach the vicinity of the target flow rate can be shortened by performing the drive control operation of switching from the feedforward control to the feedback control after the feedforward control is performed, as shown in FIG. 4. In addition, since the feedback control is started when the flow rate of the pumps 63, 72 reaches the vicinity of the target flow rate, the flow rate due to the feedback control can be suppressed. In particular, in the configuration in which two pumps 63, 72 are arranged in the dialysis fluid circuit 41 as in this embodiment, the feedback control of each pump 63, 72 is mutually influenced, and thus disturbances with large amplitudes are likely to occur. In addition, in this embodiment, the temperature adjustment of the dialysis fluid in the temperature adjustment means not shown and the concentration adjustment in the dialysis fluid preparation unit 51 are performed simultaneously with the flow rate adjustment by the pumps 63, 72, so that these feedback controls affect each other and disturbances with large amplitudes are likely to occur. In contrast, the above drive control operation can prevent or suppress the occurrence of disturbances with large amplitudes. This makes it possible to suppress pressure fluctuations in the dialysate circuit 41, and therefore the load on the piping of the dialysate circuit 41, as well as the load on the dialyzer 10 and the load on the patient C, can also be suppressed.

[0049] Furthermore, according to the configuration of the above embodiment, when switching the communication of the second bypass flow path 75, a discharge pump drive control operation is performed in which feedforward control is performed and then switched to feedback control, thereby eliminating the influence of a detection error of the discharge side control flow meter 73 that occurs when switching the communication of the second bypass flow path 75. As a result, stable flow rate control can be performed even when switching the communication of the second bypass flow path 75.

[0050] In addition, according to the configuration of the above embodiment, a proportional relation between the flow rates of the pumps 63, 72 and the command values ​​is obtained by performing a calibration operation, and feedforward control is performed using the command values ​​based on this, so that the feedforward control can be performed with high accuracy.

[0051] (Modification) Although the embodiments of the present invention have been described above, the invention according to the claims is not limited to the above-described embodiments. It should be noted that not all of the combinations of features described in the embodiments are essential to the means for solving the problems of the invention.

[0052] For example, in the above embodiment, the feedforward control is switched to the feedback control when a predetermined time has elapsed in the supply pump drive control operation and the drainage pump drive control operation, but the feedforward control may be switched to the feedback control when a predetermined flow rate is reached. Specifically, the feedforward control may be switched to the feedback control when the flow rates of the pumps 63, 72 reach a range close to the target flow rate, for example, on the condition that the flow rates of the pumps 63, 72 reach a range close to the target flow rate. That is, the control unit 22 may be configured to perform the feedforward control in the supply pump drive control operation and the drainage pump drive control operation until the flow rates reach a predetermined range close to the target flow rate, and to switch from the feedforward control to the feedback control after the flow rates reach a predetermined range close to the target flow rate. In such a case, for example, as shown in FIG. 7, instead of the step (S33) of determining whether a predetermined time has elapsed, a step (S51) is performed in which the flow rate of the supply pump 63 is monitored by a flow rate detection unit such as a supply side control flow meter 64, and whether the flow rate of the supply pump 63 has reached a predetermined range of the vicinity of the target flow rate (for example, a range of the target flow rate ±10%). Then, when it is determined (detected) that the flow rate of the supply pump 63 has reached the predetermined range of the vicinity of the target flow rate, the control is switched from feedforward control to feedback control. Note that, although an example of the supply pump drive control operation is given in FIG. 7, in the case of the drainage pump drive control operation, the step of S43 in FIG. 6 is changed to a step of monitoring the flow rate of the drainage pump 72 by a flow rate detection unit such as a discharge side control flow meter 73, and determining whether the flow rate of the drainage pump 72 has reached a predetermined range of the vicinity of the target flow rate (for example, a range of the target flow rate ±10%). Also, a configuration may be adopted in which both the time and the flow rate are monitored, and when either one of the time condition or the flow rate condition is satisfied, the control is switched from feedforward control to feedback control.

[0053] In the above embodiment, the proportional relation equation is calculated based on two command values ​​for a flow rate of 300 mL / min and a flow rate of 500 mL / min in the calibration operation, but the present invention is not limited to this as long as command values ​​for a plurality of mutually different flow rates are obtained and the proportional relation equation is calculated based on the command values ​​for the plurality of flow rates obtained. That is, the calibration operation may be configured to obtain command values ​​for three or more flow rates and calculate the proportional relation equation based on these.

[0054] Furthermore, the numerical values ​​described in the above embodiment and this modified example are merely examples and may be changed as appropriate.

[0055] Furthermore, feedforward control and feedback control may be combined in any manner without departing from the spirit of the present invention. For example, feedback control may be performed first, then switched to feedforward control, and then switched back to feedback control. Furthermore, feedforward control may be temporarily interrupted before switching to feedback control.

[0056] (Summary of the embodiment) Next, the technical ideas understood from the above-described embodiment will be described by using the reference numerals and the like in the embodiment. However, the reference numerals and the like in the following description do not limit the components in the claims to the members and the like specifically shown in the embodiment.

[0057] The blood purification device (1) performs blood purification therapy via a blood purifier (10) that purifies the blood of a patient (C), comprising: a dialysis fluid circuit (41) that supplies dialysis fluid to the blood purifier (10) and discharges the dialysis fluid from the blood purifier (10); a fluid delivery pump (63, 72) that is disposed in the dialysis fluid circuit (41) and delivers the dialysis fluid in the dialysis fluid circuit (41); a drive control unit (22) that executes a drive control operation to control the fluid delivery pump (63, 72) so that a flow rate of the fluid delivery pump (63) becomes a target flow rate; and a flow rate detection unit (64, 73) that detects the flow rate of the fluid delivery pump (63, 72), wherein in the drive control operation, feedforward control is performed that is not based on a detection value of the flow rate detection unit (64, 73), and when a predetermined time has elapsed or a predetermined flow rate has been reached, the blood purification device (1) switches from the feedforward control to feedback control that is based on the detection value of the flow rate detection unit (64, 73). This makes it possible to shorten the time it takes for the flow rate of the liquid feed pump to reach close to the target flow rate, and also to suppress fluctuations in the flow rate of the liquid feed pump. The blood purification device (1) according to item (1), wherein the dialysis fluid circuit (41) has a dialysis fluid supply flow path (52) which supplies unused dialysis fluid to the blood purifier (10) and a dialysis fluid discharge flow path (53) which discharges used dialysis fluid from the blood purifier (10), and the fluid delivery pumps (63, 72) include a first fluid delivery pump (63) disposed in the dialysis fluid supply flow path (52) and a second fluid delivery pump (72) disposed in the dialysis fluid discharge flow path (53), and the drive control unit (22) executes the drive control operation as a control operation of the first fluid delivery pump (63) when the first fluid delivery pump (63) is started, when the first fluid delivery pump (63) is restored, and / or when a target flow rate of the first fluid delivery pump (63) is changed. This makes it possible to shorten the time it takes for the flow rate of the liquid delivery pump to reach close to the target flow rate when the liquid delivery pump is started up, restarted, or the target flow rate is changed, and also makes it possible to suppress fluctuations in the flow rate of the liquid delivery pump. <3> The dialysate circuit (41) includes a dialysate supply flow path (52) for supplying unused dialysate to the blood purifier (10), a dialysate discharge flow path (53) for discharging used dialysate from the blood purifier (10), a bypass flow path (75) connected to the dialysate discharge flow path (53) and for releasing pressure in the dialysate discharge flow path (53), and a connected state in which the bypass flow path (75) is connected to the dialysate discharge flow path (53) and a non-connected state in which the bypass flow path (75) is not connected to the dialysate discharge flow path (53). and a solenoid valve (76) for switching a flow path state between a connected state and a non-connected state, the fluid delivery pumps (63, 72) including a first fluid delivery pump (63) disposed in the dialysis fluid supply flow path (52) and a second fluid delivery pump (72) disposed in the dialysis fluid discharge flow path (53), and the drive control unit (22) executes the drive control operation as a control operation of the second fluid delivery pump (72) when switching from the connected state to the non-connected state by the solenoid valve (76). This makes it possible to control the liquid delivery pump without being affected by detection errors of the flow meter that occur when communication of the bypass flow path is switched. <4> The blood purification device (1) described in any one of <1> to <3>, further comprising a calibration unit (22) that acquires calibration information relating a command value for the fluid delivery pump (63, 72) to the flow rate, and in the feedforward control, the fluid delivery pump (63, 72) is controlled by a command value based on the calibration information acquired by the calibration unit (22). This allows feedforward control to be performed with high precision. <5> The blood purification device (1) described in <4>, wherein the calibration unit (22) executes the feedback control on the liquid delivery pump (63, 72) by setting a plurality of mutually different flow rates as target flow rates, thereby creating a state in which liquid is delivered at the plurality of flow rates, thereby obtaining command values ​​for the liquid delivery pump (63, 72) corresponding to the plurality of flow rates, and calculates a relational equation as the calibration information based on the obtained command values ​​for the plurality of flow rates. This allows the feedforward control to be performed with greater precision. <6> The blood purification device (1) described in <5>, wherein the calibration unit (22) determines whether or not there is an abnormality in the liquid delivery pump (63, 72) or the flow rate detection unit (64, 73) based on whether the calculated relational equation is correct. This allows the abnormality determination to be performed during the calibration operation, making it possible to easily detect the abnormality. <7> The blood purification device (1) described in <5> or <6>, wherein the calibration unit (22) determines that there is an abnormality in the liquid delivery pump (63, 72) or the flow detection unit (64, 73) when the flow rate of the liquid delivery pump (63, 72) does not reach a target flow rate through the feedback control when obtaining the command values ​​for the multiple flow rates. This allows the abnormality determination to be performed during the calibration operation, making it possible to easily detect the abnormality. <8> A control method for a fluid delivery pump (63, 72) for controlling a fluid delivery pump (63, 72) arranged in a dialysis fluid circuit (41) of a blood purification device (1) so that the flow rate of the fluid delivery pump (63, 72) becomes a target flow rate, the control method for the fluid delivery pump (63, 72) performing feedforward control not based on a detection value of a flow rate detection unit (64, 73) that detects the flow rate of the fluid delivery pump (63, 72), and switching from the feedforward control to feedback control based on the detection value of the flow rate detection unit (64, 73) under the condition that a predetermined time has elapsed or a predetermined flow rate has been reached. This makes it possible to shorten the time it takes for the flow rate of the liquid feed pump to reach close to the target flow rate, and also to suppress fluctuations in the flow rate of the liquid feed pump. [Explanation of symbols]

[0058] 1: blood purification device, 10: dialyzer, 22: control unit, 41: dialysis fluid circuit, 52: dialysis fluid supply flow path, 53: dialysis fluid discharge flow path, 63: supply pump, 64: flow meter for supply side control, 72: drain pump, 73: flow meter for discharge side control, 75: second bypass flow path, 76: third solenoid valve, C: patient

Claims

1. A blood purification apparatus for performing blood purification treatment through a blood purifier for purifying a patient's blood, a dialysate circuit for supplying dialysate to the blood purifier and discharging the dialysate from the blood purifier, a liquid feed pump disposed in the dialysate circuit for feeding the dialysate in the dialysate circuit, a drive control unit that executes a drive control operation for controlling the liquid feed pump so that the flow rate of the liquid feed pump becomes a target flow rate, a flow rate detection unit for detecting the flow rate of the liquid feed pump, and in the drive control operation, perform feedforward control not based on the detection value of the flow rate detection unit, and switch from the feedforward control to feedback control based on the detection value of the flow rate detection unit on the condition that a predetermined time has elapsed or a predetermined flow rate has been reached. A blood purification apparatus.

2. The dialysate circuit has a dialysate supply passage for supplying the dialysate before use to the blood purifier, and a dialysate discharge passage for discharging the used dialysate from the blood purifier, As the liquid feed pump, a first liquid feed pump disposed in the dialysate supply passage, and a second liquid feed pump disposed in the dialysate discharge passage, When the first liquid feed pump starts, when the first liquid feed pump returns, and / or when the target flow rate of the first liquid feed pump is changed, the drive control unit executes the drive control operation as the control operation of the first liquid feed pump. The blood purification apparatus according to claim 1.

3. The dialysate circuit has a dialysate supply passage for supplying the dialysate before use to the blood purifier, and a dialysate discharge passage for discharging the used dialysate from the blood purifier, a bypass passage connected to the dialysate discharge passage for releasing the pressure of the dialysate discharge passage, and a solenoid valve for switching the flow path state between a communicating state in which the bypass passage communicates with the dialysate discharge passage and a non-communicating state in which the bypass passage does not communicate with the dialysate discharge passage, As the liquid feed pump, a first liquid feed pump disposed in the dialysate supply passage, and a second liquid feed pump disposed in the dialysate discharge passage, When the solenoid valve switches from the communicating state to the non-communicating state, the drive control unit executes the drive control operation as the control operation of the second liquid feed pump. The blood purification apparatus according to claim 1.

4. It further includes a calibration unit that acquires calibration information associating a command value for the liquid feeding pump with the flow rate. In the feedforward control, the liquid feeding pump is controlled by a command value based on the calibration information acquired by the calibration unit. The blood purification device according to any one of claims 1 to 3.

5. The calibration unit forms a state in which liquid is fed at the plurality of flow rates by executing feedback control for the liquid feeding pump with a plurality of mutually different flow rates as target flow rates, thereby obtaining command values of the liquid feeding pump corresponding to the plurality of flow rates, and calculates a relational expression as the calibration information based on the obtained command values for the plurality of flow rates. The blood purification device according to claim 4.

6. The calibration unit determines the presence or absence of an abnormality in the liquid feeding pump or the flow rate detection unit based on the correctness of the calculated relational expression. The blood purification device according to claim 5.

7. When the flow rate of the liquid feeding pump does not reach the target flow rate by the feedback control when the calibration unit obtains the command values for the plurality of flow rates, the calibration unit determines that there is an abnormality in the liquid feeding pump or the flow rate detection unit. The blood purification device according to claim 5.

8. The liquid feeding pump includes a first liquid feeding pump and a second liquid feeding pump. The dialysate circuit A dialysate supply channel in which the first liquid feeding pump is arranged and that supplies dialysate before use to the blood purifier, A dialysate discharge channel in which the second liquid feeding pump is arranged and that discharges used dialysate from the blood purifier, A bypass channel that is connected before and after the second liquid feeding pump in the dialysate discharge channel and that releases the pressure of the dialysate discharge channel, It has a solenoid valve that switches the channel state between a communication state in which the bypass channel communicates with the dialysate discharge channel and a non-communication state in which the bypass channel does not communicate with the dialysate discharge channel. When the solenoid valve switches from the communication state to the non-communication state, the drive control unit executes the drive control operation as the control operation of the second liquid feeding pump. The blood purification device according to claim 1. According to claim 9, in the drive control operation, feedforward control not based on the detection value of the flow rate detection unit is performed, and when the flow rate of the liquid feed pump reaches within the range of ±10% of the target flow rate, the feedforward control is switched to feedback control based on the detection value of the flow rate detection unit. The blood purification device according to claim 1.

10. A control method for a liquid feed pump that controls the liquid feed pump so that the flow rate of the liquid feed pump disposed in the dialysate circuit of a blood purification device becomes a target flow rate, performing feedforward control not based on the detection value of a flow rate detection unit that detects the flow rate of the liquid feed pump, and switching from the feedforward control to feedback control based on the detection value of the flow rate detection unit on the condition that a predetermined time has elapsed or a predetermined flow rate has been reached. A control method for a liquid feed pump.

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