Blood purification device and method for controlling feed pump

Abstract

A blood purification device (1) is provided with: a dialysate circuit (41) that discharges dialysate from a dialyzer (10) while supplying dialysate to the dialyzer (10); a liquid supply pump (63) that is disposed in the dialysate circuit (41); and a control unit (22) that executes 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 a target flow rate, performs feed-forward control during the liquid supply pump drive control operation, and switches the feed-forward control to the feedback control on the condition that a predetermined time has elapsed.

Description

Technical Field

[0001] The invention relates to a blood purification device and a control method for a liquid feeding pump. Background Art

[0002] As a blood purification device, the driving control of the liquid delivery pump is performed by feedback control (see Patent Document 1). The blood purification device includes: a blood purifier, a dialysate pipeline for supplying dialysate to the blood purifier, a drainage pipeline for discharging drainage from the blood purifier, a liquid delivery pump (dialysate pump) arranged in the dialysate pipeline, and a water balance detection unit for detecting the water balance (water removal) between the dialysate and the drainage, and the driving of the liquid delivery pump is controlled by feeding back the detection result detected by the water balance detection unit.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2020-137190 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] However, in conventional blood purification devices, it takes some time for the flow rate of the liquid delivery pump to reach the target flow rate, and the flow rate of the dialysate may change due to the feedback control of the liquid delivery pump. When the flow rate changes, it will interfere with the feedback control of other actuators (such as heaters, etc.).

[0008] Therefore, an object of the present invention is to provide a method for driving and controlling a blood purification device and a fluid delivery pump, which can shorten the time until the flow rate of the fluid delivery pump reaches near the target flow rate and can suppress flow rate fluctuations caused by feedback control.

[0009] Solutions for solving problems

[0010] In a blood purification device according to one embodiment of the present invention, the blood purification device performs blood purification treatment by means of a blood purifier that purifies the patient's blood, and the blood purification device comprises: a dialysate circuit, which supplies dialysate to the blood purifier while discharging dialysate from the blood purifier; a fluid delivery pump, which is disposed in the dialysate circuit and delivers dialysate in the dialysate circuit; a drive control unit, which executes a drive control action for controlling the fluid delivery pump so that the flow rate of the fluid delivery pump is a target flow rate; and a flow detection unit, which detects the flow rate of the fluid delivery pump; feedforward control is performed in the drive control action, and the feedforward control is not performed based on the detection value of the flow detection unit, but is switched from the feedforward control to feedback control based on the detection value of the flow detection unit on the condition that a specified time has passed or a specified flow rate has been reached.

[0011] Furthermore, in a control method for a fluid delivery pump according to an embodiment of the present invention, the control method is used to control the fluid delivery pump so that the flow rate of the fluid delivery pump arranged in a dialysate circuit of a blood purification device reaches a target flow rate, and feedforward control is performed. The feedforward control is not performed based on the detection value of a flow detection unit that detects the flow rate of the fluid delivery pump, but is switched from the feedback control to the feedback control based on the detection value of the flow detection unit, subject to the passage of a specified time or the arrival of a specified flow rate.

[0012] Effects of the Invention

[0013] According to one embodiment of the present invention, the time until the flow rate of the liquid delivery pump reaches near the target flow rate can be shortened, and the flow rate fluctuation caused by feedback control can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] [ Figure 1 ] is a schematic structural diagram showing the structure of a blood purification device related to an embodiment of the present invention.

[0015] [ Figure 2 ] is a flowchart showing the first half of the calibration operation.

[0016] [ Figure 3 ] is a flowchart showing the second half of the calibration operation.

[0017] [ Figure 4 ] is a schematic diagram showing an example of the command value and flow rate relative to time in the liquid supply pump drive control action and the liquid discharge pump drive control action.

[0018] [ Figure 5 ] is a flow chart showing the liquid supply pump drive control action.

[0019] [ Figure 6] is a flow chart showing the liquid discharge pump drive control action.

[0020] [ Figure 7 ] is a flow chart showing a modified example of the liquid supply pump drive control action. DETAILED DESCRIPTION

[0021] Hereinafter, a blood purification device related to an embodiment of the present invention will be described with reference to the accompanying drawings. The blood purification device is a medical device for implementing blood purification treatment for purifying the blood of a patient through a dialyzer. In particular, the blood purification device uses feedforward control and feedback control to quickly reach the vicinity of the target flow rate, and can perform stable flow control.

[0022] (Composition of blood purification device)

[0023] like Figure 1 As shown, the blood purification device 1 has: a dialyzer 10 for purifying the blood of a patient C, an extracorporeal circulation unit 11 for circulating the blood of the patient C through the dialyzer 10, and a dialysate supply and discharge unit 12 connected to the dialyzer 10 and supplying dialysate to the dialyzer 10 while discharging the dialysate from the dialyzer 10. The extracorporeal circulation unit 11 and the dialysate supply and discharge unit 12 are independent units, and the dialyzer 10 is mounted on the extracorporeal circulation unit 11 by a fixing clamp 13 in a freely loadable and removable manner. The dialyzer 10 is an example of a blood purifier.

[0024] The dialyzer 10 is equipped with a blood purification membrane (a hollow fiber type hemodialysis membrane or hemodiafiltration membrane, or a flat membrane type hemodialysis membrane or hemofiltration membrane). In addition, the dialyzer 10 has a blood inlet 10a for introducing blood and a blood outlet 10b for discharging the introduced blood, and also has a dialysate inlet 10c for introducing a dialysate and a dialysate outlet 10d for discharging the introduced dialysate. In the dialyzer 10, the blood and the dialysate are brought into contact through the blood purification membrane, thereby purifying the blood. In addition, in the dialyzer 10, by controlling the supply and discharge of the dialysate supply and discharge unit 12, it is possible to remove water from the blood.

[0025] 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.

[0026] The extracorporeal circulation circuit 21 includes an arterial blood flow path 31, a venous blood flow path 32, and a blood pump 34. The arterial blood flow path 31 is connected to the blood inlet port 10a of the dialyzer 10 to introduce blood collected from the blood vessels of the patient C into the dialyzer 10. The venous blood flow path 32 is connected to the blood outlet port 10b of the dialyzer 10 to return the blood discharged from the dialyzer 10 to the blood vessels of the patient C. The blood pump 34 is disposed on the arterial blood flow path 31 to circulate blood. By driving the blood pump 34, the blood from the patient C is introduced into the dialyzer 10 through the arterial blood flow path 31, and after passing through the dialyzer 10, the blood is purified and then returned to the patient C through the venous blood flow path 32. Thus, the blood of the patient C is purified.

[0027] (Configuration of the Dialysate Supply and Drainage Unit)

[0028] The dialysate supply and discharge unit 12 includes a dialysate circuit 41 for supplying dialysate to the dialyzer 10 and discharging dialysate from the dialyzer 10 , and a dialysate supply and discharge unit-side control unit 42 .

[0029] The dialysate circuit 41 comprises: a dialysate preparation section 51 for refining dialysate; a dialysate supply flow path 52 connected to the dialysate inlet 10c of the dialyzer 10 and supplying the dialysate before use after being refined by the dialysate preparation section 51 to the dialyzer 10; a drainage discharge flow path 53 connected to the dialysate discharge port 10d of the dialyzer 10 and recovering and discharging the dialysate after use from the dialyzer 10; and a first bypass flow path 54, which is connected to the dialysate supply flow path 52 and the dialysate discharge flow path 53 before and after the dialyzer 10, and connects the dialysate supply flow path 52 and the dialysate discharge flow path 53 without passing through the dialyzer 10.

[0030] The dialysate preparation unit 51 prepares the dialysate using the supplied pure water and the dialyzing agent composed of a concentrated solution or a powder. The pure water supplied to the dialysate preparation unit 51 may be supplied from a pure water production unit installed on the dialysate supply and discharge unit 12, or may be supplied from a pure water production device installed outside the dialysate supply and discharge unit 12. In addition, the dialysate preparation unit 51 may also be omitted, and for example, the dialysate may be supplied to the dialysate supply and discharge unit 12 from an external dialysate supply device or the like.

[0031] The dialysate supply flow path 52 is provided with a liquid supply pump 63, a supply side control flow meter 64, a supply side protection flow meter 65, and a first electromagnetic valve 66 from the upstream side. The liquid supply pump 63 is a liquid delivery pump that delivers the dialysate in the dialysate supply flow path 52. By driving the liquid supply pump 63, the dialysate is supplied to the dialyzer 10. The liquid supply pump 63 is an example of a first liquid delivery pump.

[0032] The supply-side control flowmeter 64 and the supply-side protection flowmeter 65 are disposed on the downstream side of the liquid supply pump 63, and are flowmeters for detecting the flow rate of the liquid supply pump 63 (i.e., the flow rate of the dialysate). The supply-side control flowmeter 64 is a control flowmeter for detecting the flow rate of the liquid supply pump 63 to control the liquid supply pump 63. On the other hand, the supply-side protection flowmeter 65 is a protection flowmeter for ensuring 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 detection unit.

[0033] The first electromagnetic valve 66 is disposed on the downstream side of the connection position to the first bypass flow path 54 , and is one of the electromagnetic valves that switches the flow path from the flow path passing through the dialyzer 10 to the first bypass flow path 54 .

[0034] The dialysate discharge flow path 53 is provided with a second electromagnetic valve 71, a discharge pump 72, a discharge side control flow meter 73, and a discharge side protection flow meter 74 from the upstream side. In addition, the dialysate discharge flow path 53 is provided with a second bypass flow path 75 connected before and after the discharge pump 72.

[0035] The second electromagnetic valve 71 is disposed on the upstream side of the connection position to the first bypass flow path 54 , and is one of the electromagnetic valves that switches the flow path from the flow path passing through the dialyzer 10 to the first bypass flow path 54 .

[0036] The discharge pump 72 is a liquid delivery pump for delivering the dialysate to the dialysate discharge flow path 53. The dialysate from the dialyzer 10 is discharged by driving the discharge pump 72. By controlling the liquid supply pump 63 and the discharge pump 72, the flow rate of the liquid supply pump 63 and the flow rate of the discharge pump 72 are adjusted, thereby controlling the amount of water removed from the blood in the dialyzer 10. The discharge pump 72 is an example of a second liquid delivery pump.

[0037] The discharge side control flowmeter 73 and the discharge side protection flowmeter 74 are disposed on the downstream side of the discharge pump 72, and are flowmeters for detecting the flow rate of the discharge pump 72 (i.e., the flow rate of the dialysate). The discharge side control flowmeter 73 is a control flowmeter for detecting the flow rate of the discharge pump 72 to control the discharge pump 72. On the other hand, the discharge side protection flowmeter 74 is a protection flowmeter for ensuring 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 detection unit.

[0038] 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 front and rear of the discharge pump 72 in the dialysate discharge flow path 53. In addition, the second bypass flow path 75 is provided with a third electromagnetic valve 76, and the third electromagnetic valve 76 switches the flow path state between a connected state in which the second bypass flow path 75 is connected to the dialysate discharge flow path 53 and a non-connected state in which the second bypass flow path is not connected to the dialysate discharge flow path 53. By opening the third electromagnetic valve 76, the dialysate discharge flow path 53 is connected to the second bypass flow path 75, the pressure in the dialysate circuit 41 is released, and the dialysate discharge flow path 53 is placed in a pressure release state. On the other hand, by closing the third electromagnetic valve 76, the dialysate discharge flow path 53 is disconnected from the second bypass flow path 75, and the dialysate discharge flow path 53 is returned to a normal state (non-pressure release state).

[0039] The fourth electromagnetic valve 55 is provided in the first bypass flow path 54. By opening the fourth electromagnetic valve 55 and closing the first electromagnetic valve 66 and the second electromagnetic 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 electromagnetic valve 55 and opening the first electromagnetic valve 66 and the second electromagnetic valve 71, the flow path is switched from the first bypass flow path 54 to the flow path passing through the dialyzer 10.

[0040] The dialysate supply and discharge unit side control unit 42 communicates with the control unit 22 of the extracorporeal circulation unit 11, and controls the supply pump 63, the discharge pump 72, and the electromagnetic valves 55, 66, 71, and 76 according to the instructions of the control unit 22. The dialysate supply and discharge unit side control unit 42 is composed of a suitable combination of a computing element such as a CPU, a memory, software, an interface, and a communication unit.

[0041] (Control unit and its control)

[0042] Here, regarding the control unit 22 of the extracorporeal circulation unit 11 and the control of the control unit 22, refer to Figures 1 to 6 The control unit 22 controls the blood pump 34, and communicates with the dialysate supply and discharge unit side control unit 42, and controls the supply pump 63, the discharge pump 72 and the electromagnetic valves 55, 66, 71 and 76 through the dialysate supply and discharge unit side control unit 42. In addition, the control unit 22 also receives the detection values ​​of the flow meters 64, 65, 73 and 74 through the dialysate supply and discharge unit side control unit 42. In particular, the control unit 22 performs calibration actions, supply pump drive control actions and discharge pump drive control actions. The control unit 22 is implemented by appropriately combining computing elements such as CPUs, memories, software, interfaces, communication units, etc. In addition, the control unit 22 is an example of a drive control unit and a calibration unit, and the supply pump drive control action and the discharge pump drive control action are examples of drive control actions and drive control methods of a feed pump.

[0043] The calibration operation is an operation for obtaining a proportional relationship between the command value and the flow rate used in the feedforward control, wherein the command values ​​at two different flow rates are obtained and the proportional relationship is calculated based on them. The proportional relationship is an example of calibration information that associates the command value and the flow rate for the pumps 63 and 72. In this embodiment, 300 mL / min and 500 mL / min are used as an example of the above two flow rates.

[0044] Furthermore, in the present embodiment, for example, a DA value is used as an instruction value. The DA value is an instruction value output from the control unit 22 to each pump (supply pump 63, discharge pump 72, etc.) through the dialysate supply and discharge unit side control unit 42. Strictly speaking, the DA value is a digital signal having a 16-bit representation, which is output from the microcontroller of the control unit 22 through the microcontroller of the dialysate supply and discharge unit side control unit 42 to the DA converter, and is converted into a corresponding instruction voltage in the DA converter, and the converted instruction voltage is input into each pump 63, 72. Each pump 63, 72 is driven by the input instruction voltage. Furthermore, the control unit 22 or the dialysate supply and discharge unit side control unit 42 can be configured to have a DA converter and perform conversion from a DA value to an instruction voltage, or the blood purification device 1 can be configured to have a DA converter separate from the control unit 22 and the dialysate supply and discharge unit side control unit 42.

[0045] Figure 2 and Figure 3 is a flow chart showing the calibration action. Figure 2 As shown, in the calibration operation, the first electromagnetic valve 66, the second electromagnetic valve 71 and the third electromagnetic valve 76 are first closed (S1), and then the fourth electromagnetic valve 55 is opened (S2). Thus, the flow path through the dialyzer 10 is switched to the first bypass flow path 54, and the dialysate discharge flow path 53 is placed in a non-pressure release state.

[0046] Thereafter, the liquid supply pump 63 and the liquid discharge pump 72 are driven by feedback control with 300 mL / min as the target flow rate (S3). Thus, the dialysate is delivered at a flow rate of 300 mL / min. By implementing the feedback control, if the flow rate detected by each control flow meter 64, 73 does not reach the vicinity range of 300 mL / min (for example, the range of ±2) for a predetermined number of seconds (S4: No), and if a predetermined time has passed (S5: Yes), it is determined that each pump 63, 72 or each control flow meter 64, 73 has an abnormality, an alarm is output (S6), and this operation is terminated. That is, by feedback control, if the flow rate of the liquid supply pump 63 and the liquid discharge pump 72 does not reach the target flow rate, it is determined that each pump 63, 72 or each control flow meter 64, 73 has an abnormality. In addition, the so-called feedback control refers to the control of regularly feeding back the detection value (flow rate) of the control flow meter 64, 73 to change the instruction value, and driving the pump 63, 72 according to the changed instruction value.

[0047] On the other hand, by implementing the feedback control, when the flow rate detected by each control flow meter 64, 73 is in the vicinity of 300 mL / min for a predetermined number of seconds (S4: Yes), the command values ​​of the liquid supply pump 63 and the liquid discharge pump 72 are recorded (S7). Thus, the command values ​​of each pump 63, 72 when the flow rate is 300 mL / min are obtained.

[0048] Then, the liquid supply pump 63 and the liquid discharge pump 72 are driven by feedback control with a target flow rate of 500 mL / min (S8). Thus, the dialysate is delivered at a flow rate of 500 mL / min. By implementing feedback control, when the flow rate detected by each control flow meter 64, 73 continues for a specified number of seconds and does not reach the vicinity of 500 mL / min (for example, ±2 range) (S9: No), and when a specified time has passed (S10: Yes), it is determined that each pump 63, 72 or each control flow meter 64, 73 has an abnormality, an alarm is output (S11), and this action is terminated.

[0049] On the other hand, by implementing the feedback control, when the flow rate detected by each control flow meter 64, 73 is in the vicinity of 500 mL / min for a predetermined number of seconds (S9: Yes), the command values ​​of the liquid supply pump 63 and the liquid discharge pump 72 are recorded (S12). Thus, the command values ​​of each pump 63, 72 when the flow rate is 500 mL / min are obtained.

[0050] After the first instruction value recording process (S2 to S12) is completed, Figure 3As shown, the second recording process of the instruction value for confirmation is performed (S13 to S22). That is, as in the first recording process, first, the liquid supply pump 63 and the liquid discharge pump 72 are driven by feedback control with 300 mL / min as the target flow rate (S13). Through the implementation of feedback control, when the flow rate detected by each control flow meter 64, 73 does not reach the vicinity of 300 mL / min for a specified number of seconds (S14: No), and when the specified time has passed (S15: Yes), it is determined that each pump 63, 72 or each control flow meter 64, 73 has an abnormality, an alarm is output (S16), and this action is terminated.

[0051] On the other hand, when the flow rates detected by the control flow meters 64 and 73 remain in the vicinity of 300 mL / min for a predetermined number of seconds through feedback control (S14: Yes), the command values ​​of the liquid supply pump 63 and the liquid discharge pump 72 are recorded (S17).

[0052] Then, the liquid supply pump 63 and the liquid discharge pump 72 are driven by feedback control with a target flow rate of 500 mL / min (S18). By implementing the feedback control, when the flow rate detected by each control flow meter 64, 73 does not reach the vicinity of 500 mL / min for a specified number of seconds (S19: No), and when a specified 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 action is terminated. On the other hand, by implementing the feedback control, when the flow rate detected by each control flow meter 64, 73 is in the vicinity of 500 mL / min for a specified number of seconds (S18: Yes), the command values ​​of the liquid supply pump 63 and the liquid discharge pump 72 are recorded (S22).

[0053] If the second recording process is completed, it is determined whether the instruction value recorded for the first time is consistent with the instruction value recorded for the second time for each flow rate (300mL / min and 500mL / min) of each pump 63, 72 (S23). If it is determined that the instruction value for the first time is inconsistent with the instruction value for the second time (S23: No), an alarm is output (S24) and the present action is terminated. On the other hand, if it is determined that the instruction value for the first time is consistent with the instruction value for the second time (S23: Yes), the proportional relationship between the instruction value and the flow rate is calculated based on the instruction value for the second time (S25). That is, the proportional relationship between the instruction value in the liquid supply pump 63 and the flow rate is calculated based on the instruction value of the following liquid supply pump 63 recorded by the second recording process, and the instruction values ​​of the liquid supply pump 63 are, respectively, the instruction value of the liquid supply pump 63 when the flow rate is 300mL / min and the instruction value of the liquid supply pump 63 when the flow rate is 500mL / min. In addition, the proportional relationship between the command value of the discharge pump 72 and the flow rate is calculated based on the command value of the discharge pump 72 recorded through the second recording process. The command value of the discharge pump 72 is the command value of the discharge pump 72 when the flow rate is 300mL / min and the command value of the discharge pump 72 when the flow rate is 500mL / min.

[0054] If the proportional relationship formula of each pump 63, 72 is calculated, it is determined whether each pump 63, 72 or each control flow meter 64, 73 has an abnormality based on whether the proportional relationship formula (mainly the slope) of each pump 63, 72 is within the specified range. That is, it is determined whether each pump 63, 72 or each control flow meter 64, 73 has an abnormality based on whether the calculated proportional relationship formula of each pump 63, 72 is correct. If the proportional relationship formula of each pump 63, 72 exceeds the specified range and is determined to be an abnormal value (S26: No), it is determined that each pump 63, 72 or each control flow meter 64, 73 has an abnormality, and an alarm is output (S27). On the other hand, if the proportional relationship formula of each pump 63, 72 is within the specified range and is determined to be a normal value (S26: Yes), it is determined that each pump 63, 72 or each control flow meter 64, 73 has no abnormality, and this operation is terminated. As described above, in the present embodiment, by performing abnormality determination of each pump 63, 72 or each control flow meter 64, 73 during the calibration operation for acquiring the proportional relationship expression, abnormality detection can be easily performed.

[0055] The liquid supply pump driving control action is to control the driving action of the liquid supply pump 63 so that the flow rate of the liquid supply pump 63 becomes the target flow rate, such as Figure 4As shown, until the prescribed time for estimating that the target flow rate has been reached by feedforward control (FF control), feedforward control is performed, and the feedforward control is not performed based on the detection value of the supply side control flow meter 64. After the prescribed time has passed, the feedforward control is switched to feedback control (FB control) based on the detection value of the supply side control flow meter 64. The so-called feedforward control is a control that drives the pumps 63 and 72 based on a certain command value instead of the detection value of the supply side control flow meter 64. In the liquid supply pump drive control action, the command value of the target flow rate calculated by the proportional relationship obtained in the calibration action is used as the command value of the feedforward control. In this embodiment, if the liquid supply pump 63 is driven for 10 seconds according to the feedforward control of the command value, it is estimated that the flow rate of the liquid supply pump 63 will reach the target flow rate, so the above-mentioned "prescribed time for estimating that the target flow rate has been reached by feedforward control" is 10 seconds.

[0056] Figure 5 The flow chart of the liquid supply pump drive control action is shown in Figure 2. Figure 5 As shown, in the liquid supply pump drive control action, first, the command value relative to the target flow rate is calculated based on the proportional relationship formula of the liquid supply pump 63 obtained in the calibration action (S31). Then, the liquid supply pump 63 is driven by the feedforward control based on the calculated command value (S32). After the liquid supply pump 63 driven by the feedforward control is started, after the prescribed time (10 seconds) has passed (S33: Yes), the drive control of the liquid supply pump 63 is switched from the feedforward control to the feedback control (S34). Thus, this action is terminated.

[0057] The liquid discharge pump driving control action controls the driving of the liquid discharge pump 72 so that the flow rate of the liquid discharge pump 72 becomes the target flow rate, such as Figure 4 As shown in FIG. 1 , until the prescribed time for estimating that the target flow rate has been reached has passed, feedforward control is performed, and this feedforward control is not performed based on the detection value of the discharge side control flow meter 73. After the prescribed time has passed, the feedforward control is switched to feedback control based on the detection value of the discharge side control flow meter 73. In the liquid discharge pump drive control operation, the command value of the target flow rate calculated by the proportional relationship formula obtained by the calibration operation is used as the command value of the feedforward control. In the present embodiment, if the liquid discharge pump 72 is driven for 10 seconds according to the feedforward control based on the command value, it is estimated that the flow rate of the liquid discharge pump 72 will reach the target flow rate, so the "predetermined time for estimating that the target flow rate has been reached by the feedforward control" is 10 seconds.

[0058] Figure 6 The flow chart of the displacement pump drive control action is shown in Figure 2. Figure 6As shown, in the liquid discharge pump drive control action, first, the command value relative to the target flow rate is calculated based on the proportional relationship formula of the liquid discharge pump 72 obtained by the calibration action (S41). Then, the liquid discharge pump 72 is driven by the feedforward control based on the calculated command value (S42). After the predetermined time (10 seconds) has passed since the liquid discharge pump 72 was driven by the feedforward control (S43: Yes), the drive control of the liquid discharge pump 72 is switched from the feedforward control to the feedback control (S44). Thus, this action is terminated.

[0059] In the blood purification device 1, the following processes are to be performed: startup process, treatment preparation process, patient needle insertion and blood removal process, treatment process, treatment interruption process, patient needle removal and blood return process, drainage process, cleaning and disinfection process, standby process and adjustment process. The calibration action is performed during the self-diagnosis in the startup process and in the adjustment process.

[0060] On the other hand, the liquid supply pump drive control action is executed when the liquid supply pump 63 is started in the start-up process, when the liquid supply pump 63 is returned in the treatment interruption process, when the target flow rate of the liquid supply pump 63 is changed in the preparation process, the patient needle removal and blood return process, the treatment process, and the patient needle removal and blood return process. That is, the control unit 22 executes the liquid supply pump drive control action as a control action of the liquid supply pump 63 when the liquid supply pump 63 is started (when the liquid supply pump 63 is started), when the liquid supply pump 63 is returned (when the liquid supply pump 63 is returned), and when the target flow rate of the liquid supply pump 63 is changed (when the target flow rate of the liquid supply pump 63 is changed). In this way, by performing the liquid supply pump drive control action of switching to feedback control after performing feedforward control at the start and return of the liquid supply pump 63 and when the target flow rate is changed, the time for the flow rate of the liquid supply pump 63 to reach near the target flow rate can be shortened, and the flow rate fluctuation caused by feedback control can be suppressed.

[0061] Furthermore, the drainage pump drive control action is executed when the third electromagnetic valve 76 in the open state is closed in the startup process, the treatment preparation process, the patient needle insertion and blood removal process, the treatment process, the treatment interruption process, the patient needle removal and blood return process, the cleaning and disinfection process, the standby process, and the adjustment process. In other words, the drainage pump drive control action is executed when the state of opening the third electromagnetic valve 76 to connect the dialysate discharge flow path 53 and the second bypass flow path 75 is changed to closing the third electromagnetic valve 76 to make the dialysate discharge flow path 53 and the second bypass flow path 75 in a non-connected state. In other words, when the second bypass flow path 75 is switched from the connected state to the non-connected state through the third electromagnetic valve 76 (when the third electromagnetic valve 76 is switched from the connected state to the non-connected state), the control unit 22 executes the drainage pump drive control action as the control action of the drainage pump 72. In this way, when the connection of the second bypass flow path 75 is switched, the discharge pump drive control operation can be performed to switch to the feedback control after executing the feedforward control, thereby driving the discharge pump 72 without being affected by the detection error of the discharge side control flow meter 73 generated when the connection of the second bypass flow path 75 is switched. In addition, the feedforward control can be performed in the state where the third electromagnetic valve 76 is opened, and the feedforward control can be switched to the feedback control when the third electromagnetic valve 76 is closed.

[0062] (Functions and Effects of Implementation Methods)

[0063] As described above, according to the configuration of the above embodiment, after the feedforward control is implemented, the drive control operation is switched from the feedforward control to the feedback control, thereby Figure 4 As shown, the time for the flow rate of the pumps 63 and 72 to reach the vicinity of the target flow rate can be shortened. In addition, since the feedback control starts from the state where the flow rate of the pumps 63 and 72 reaches the vicinity of the target flow rate, the flow rate fluctuation caused by the feedback control can be suppressed. In particular, in the configuration in which two pumps 63 and 72 are arranged in the dialysate circuit 41 as in the present embodiment, the influence of the feedback control of each pump 63 and 72 will interact with each other, so it is easy to generate interference with a large amplitude. In addition, in the present embodiment, the dialysate temperature adjustment in the temperature adjustment mechanism not shown in the figure and the concentration adjustment in the dialysate preparation unit 51 are performed simultaneously with the flow rate adjustment of the pumps 63 and 72, so these feedback controls affect each other and large amplitude interference is easy to occur. In contrast, through the drive control action, the occurrence of large amplitude interference can be prevented or suppressed. As a result, the pressure fluctuation in the dialysate circuit 41 can be suppressed, the load on the pipeline of the dialysate circuit 41 can be reduced, and the load on the dialyzer 10 and the load on the patient C can also be suppressed.

[0064] Furthermore, according to the configuration of the above-described embodiment, when switching the connection of the second bypass flow path 75, after performing the feedforward control, the discharging pump drive control operation is switched to the feedback control, so that the flow rate is not affected by the detection error of the discharge side control flow meter 73 that occurs when switching the connection of the second bypass flow path 75. Thus, stable flow control can be achieved even when switching the connection of the second bypass flow path 75.

[0065] Furthermore, according to the configuration of the above-described embodiment, a calibration operation is performed to obtain a proportional relationship between the flow rate of the pumps 63, 72 and the command value, and feedforward control is performed based on the command value obtained therefrom, so that feedforward control can be performed with high accuracy.

[0066] (Variation example)

[0067] The embodiments of the present invention are described above, but the embodiments described above are not intended to limit the invention related to the claims. In addition, it should be noted that not all combinations of features described in the embodiments are essential to the means for solving the problems of the present invention.

[0068] For example, in the above-mentioned embodiment, the liquid supply pump drive control action and the liquid discharge pump drive control action can be configured to switch from feedforward control to feedback control based on the passage of a specified time, but can also be configured to switch from feedforward control to feedback control based on the reaching of a specified flow rate. Specifically, for example, the condition can be that the flow rate of the pumps 63 and 72 reaches a range near the target flow rate, and at the time point when the flow rate of the pumps 63 and 72 reaches a range near the target flow rate, it is possible to switch from feedforward control to feedback control. That is, the control unit 22 can be configured to perform feedforward control in the liquid supply pump drive control action and the liquid discharge pump drive control action until the flow rate reaches a specified range near the target flow rate, and switch from feedforward control to feedback control after the flow rate reaches a specified range near the target flow rate. In this case, for example, Figure 7 As shown, instead of the step (S33) of determining whether the specified time has passed, the flow rate of the liquid supply pump 63 is monitored by the flow rate detection unit such as the supply side control flow meter 64, and the step (S51) of determining whether the flow rate of the liquid supply pump 63 has reached a specified range near the target flow rate (for example, within the range of ±10% of the target flow rate) is performed. And, when it is determined (detected) that the flow rate of the liquid supply pump 63 has reached the specified range near the target flow rate, the feedforward control is switched to the feedback control. In addition, Figure 7 Although an example of the liquid supply pump drive control action is given in the above, in the case of the liquid discharge pump drive control action, Figure 6The process of S43 is changed to the following process: the flow rate of the discharge pump 72 is monitored by the flow rate detection unit such as the discharge side control flow meter 73, and it is determined whether the flow rate of the discharge pump 72 has reached a predetermined range near the target flow rate (for example, a range of ±10% of the target flow rate). In addition, it can be configured to monitor both time and flow rate at the same time, and switch from feedforward control to feedback control at the time point when either the time condition or the flow rate condition is met.

[0069] Furthermore, in the above-mentioned embodiment, the calibration operation is a configuration in which the proportional relationship expression is calculated based on the command values ​​for the two flow rates of 300 mL / min and 500 mL / min, but if the command values ​​for a plurality of flow rates that are different from each other are obtained, and the proportional relationship expression is calculated based on the command values ​​for the plurality of flow rates obtained, the configuration is not limited thereto. That is, in the calibration operation, the command values ​​for three or more flow rates may be obtained, and the proportional relationship expression may be calculated based on these command values.

[0070] In addition, the numerical values ​​described in the above-mentioned embodiment and the present modification are merely examples and can be changed as appropriate.

[0071] Furthermore, feedforward control and feedback control may be combined arbitrarily without departing from the scope of the present invention. For example, after initially performing feedback control, the control may be switched to feedforward control, and then switched to feedback control again. Alternatively, the control operation may be temporarily interrupted from feedforward control to feedback control.

[0072] (Summary of Implementation Methods)

[0073] Next, the technical concepts grasped from the above-described embodiments will be described by referring to the symbols in the embodiments. However, the symbols in the following description are not limited to the components that specifically represent the constituent elements in the claims in the embodiments.

[0074] 《1》A blood purification device (1) performs blood purification treatment by using a blood purifier (10) for purifying the blood of a patient (C). The blood purification device (1) comprises: a dialysate circuit (41) for supplying dialysate to the blood purifier (10) and discharging dialysate from the blood purifier (10); a liquid delivery pump (63, 72) for delivering dialysate in the dialysate circuit (41); and a drive control unit (22). A drive control unit (22) performs a drive control action to control the liquid delivery pump (63, 72) so that the flow rate of the liquid delivery pump (63) is a target flow rate; and a flow detection unit (64, 73) detects the flow rate of the liquid delivery pump (63, 72); a feedforward control is performed in the drive control action, and the feedforward control is not performed based on the detection value of the flow detection unit (64, 73), and is switched from the feedback control to the feedback control based on the detection value of the flow detection unit (64, 73) under the condition that a specified time has passed or a specified flow rate has been reached.

[0075] According to this, the time until the flow rate of the liquid feeding pump reaches near the target flow rate can be shortened, and the flow rate fluctuation of the liquid feeding pump can be suppressed.

[0076] 《2》 According to the blood purification device (1) described in 《1》, the dialysate circuit (41) comprises: a dialysate supply flow path (52), the dialysate supply flow path (52) being used to supply the dialysate before use to the blood purifier (10); and a dialysate discharge flow path (53), the dialysate discharge flow path (53) being used to discharge the dialysate after use from the blood purifier (10); as the liquid delivery pump (63, 72), there are: a first liquid delivery pump (63) , the first fluid delivery pump (63) is arranged in the dialysate supply flow path (52); and the second fluid delivery pump (72) is arranged in the dialysate discharge flow path (53); the drive control unit (22) executes the drive control action as the control action of the first fluid delivery pump (63) when the first fluid delivery pump (63) is started, when the first fluid delivery pump (63) returns, and / or when the target flow rate of the first fluid delivery pump (63) is changed.

[0077] According to this, when the liquid feeding pump is started, returned, or the target flow rate is changed, the time until the flow rate of the liquid feeding pump reaches near the target flow rate can be shortened, and flow rate fluctuation of the liquid feeding pump can be suppressed.

[0078] "3" According to the blood purification system (1) described in "1", the dialysate circuit (41) comprises: a dialysate supply flow path (52), which is used to supply the dialysate before use to the blood purifier (10); a dialysate discharge flow path (53), which is used to discharge the dialysate after use from the blood purifier (10); a bypass flow path (75), which is connected to the dialysate discharge flow path (53) and is used to release the pressure of the dialysate discharge flow path (53); and a solenoid valve (76), which is connected between the bypass flow path (75) and the dialysate The flow path state is switched between a connected state in which the discharge flow path (53) is connected and a non-connected state in which the bypass flow path (75) is not connected to the dialysate discharge flow path (53). The liquid delivery pump (63, 72) comprises: a first liquid delivery pump (63), which is arranged in the dialysate supply flow path (52); and a second liquid delivery pump (72), which is arranged in the dialysate discharge flow path (53); and the drive control unit (22) performs the drive control action as the control action of the second liquid delivery pump (72) when the state is switched from the connected state to the non-connected state through the solenoid valve (76).

[0079] This makes it possible to control the liquid delivery pump without being affected by a flow meter detection error that occurs when the communication of the bypass flow path is switched.

[0080] "4" The blood purification device according to any one of "1" to "3" further has a calibration unit (22) for obtaining calibration information, and the calibration information associates the instruction value for the liquid delivery pump (63, 72) with the flow rate. In the feedforward control, the liquid delivery pump (63, 72) is controlled according to the instruction value based on the calibration information obtained by the calibration unit (22).

[0081] This enables feedforward control to be performed with high accuracy.

[0082] "5" According to the blood purification device (1) described in "4", the calibration unit (22) performs the feedback control on the liquid delivery pump (63, 72) by taking a plurality of different flow rates as target flow rates, thereby forming a state in which liquid is delivered at the plurality of flow rates, thereby obtaining instruction values ​​of the liquid delivery pump (63, 72) corresponding to the plurality of flow rates, and calculating a relationship as the calibration information based on the instruction values ​​of the plurality of flow rates obtained.

[0083] Based on this, feedforward control can be performed with high precision.

[0084] «6» According to the blood purification device (1) described in «5», the calibration unit (22) determines whether there is an abnormality in the liquid delivery pump (63, 72) or the flow detection unit (64, 73) based on whether the calculated relationship is correct.

[0085] According to this, abnormality determination can be performed during the calibration operation, and abnormality detection can be easily performed.

[0086] "7" According to the blood purification device (1) described in "5" or "6", 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 the target flow rate based on the feedback control when obtaining the instruction value relative to the multiple flow rates.

[0087] This makes it possible to make an abnormality judgment during the calibration operation, thereby making it easy to detect abnormalities.

[0088] 《8》A control method for a fluid delivery pump (63, 72), the control method being used to control the fluid delivery pump (63, 72) so that the flow rate of the fluid delivery pump (63, 72) arranged in a dialysate circuit (41) of a blood purification device (1) reaches a target flow rate, and to perform feedforward control. The feedforward control is not performed based on the detection value of a flow detection unit (64, 73) that detects the flow rate of the fluid delivery pump (63, 72), but is switched from the feedforward control to feedback control based on the detection value of the flow detection unit (64, 73) based on the passage of a specified time or the arrival of a specified flow rate.

[0089] This can shorten the time it takes for the flow rate of the liquid delivery pump to reach near the target flow rate and suppress flow rate fluctuations of the liquid delivery pump.

[0090] Explanation of symbols

[0091] 1: blood purification system, 10: dialyzer, 22: control unit, 41: dialysate circuit, 52: dialysate supply flow path, 53: dialysate discharge flow path, 63: supply pump, 64: flow meter for supply side control, 72: discharge pump, 73: flow meter for discharge side control, 75: second bypass flow path, 76: third solenoid valve, C: patient.

Claims

1. A blood purification device, which performs blood purification treatment by a blood purifier that purifies the patient's blood, and which has: a dialysate circuit, which supplies dialysate to the blood purifier and discharges dialysate from the blood purifier; a liquid delivery pump, which is arranged in the dialysate circuit and delivers dialysate in the dialysate circuit; a drive control unit that performs a drive control operation to control the liquid delivery pump so that the flow rate of the liquid delivery pump reaches a target flow rate; as well as A flow detection unit, the flow detection unit detects the flow rate of the liquid delivery pump; In the drive control operation, feedforward control is performed, and the feedforward control is not performed based on the detection value of the flow detection unit. When a specified time has passed or a specified flow rate has been reached, the feedforward control is switched to feedback control based on the detection value of the flow detection unit.

2. The blood purification device according to claim 1, wherein the dialysate circuit comprises: a dialysate supply flow path for supplying dialysate before use to the blood purifier; and a dialysate discharge flow path, the dialysate discharge flow path being used to discharge the used dialysate from the blood purifier; As the liquid delivery pump, there is: a first liquid delivery pump, the first liquid delivery pump being arranged in the dialysate supply flow path; as well as a second liquid delivery pump, the second liquid delivery pump being arranged in the dialysate discharge flow path; The drive control unit performs the drive control operation as the control operation of the first liquid sending pump when the first liquid sending pump is started, when the first liquid sending pump is returned, and / or when a target flow rate of the first liquid sending pump is changed.

3. The blood purification device according to claim 1, wherein the dialysate circuit comprises: a dialysate supply flow path, the dialysate supply flow path being used to supply the dialysate before use to the blood purifier; a dialysate discharge flow path, the dialysate discharge flow path being used to discharge the used dialysate from the blood purifier; a bypass flow path, the bypass flow path being connected to the dialysate discharge flow path and being used for releasing the pressure of the dialysate discharge flow path; as well as an electromagnetic valve that switches a flow path state between a connected state in which the bypass flow path is connected to the dialysate discharge flow path and a non-connected state in which the bypass flow path is not connected to the dialysate discharge flow path, As the above-mentioned liquid delivery pump, there is: a first liquid delivery pump, the first liquid delivery pump being arranged in the dialysate supply flow path; as well as a second liquid delivery pump, the second liquid delivery pump being arranged in the dialysate discharge flow path; The drive control unit performs the drive control operation as a control operation of the second liquid feeding pump when the electromagnetic valve switches from the communication state to the non-communication state.

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

5. According to the blood purification device according to claim 4, the calibration unit performs the feedback control on the liquid delivery pump by taking a plurality of different flow rates as target flow rates, thereby forming a state in which liquid is delivered at the plurality of flow rates, thereby obtaining instruction values ​​of the liquid delivery pump corresponding to the plurality of flow rates, and calculating a relationship as calibration information based on the instruction values ​​of the plurality of flow rates obtained. 6 . The blood purification device according to claim 5 , wherein the calibration unit determines whether or not there is an abnormality in the liquid delivery pump or the flow rate detection unit based on whether the calculated relationship is correct.

7. According to the blood purification device according to claim 5, the calibration unit determines that there is an abnormality in the liquid delivery pump or the flow detection unit when the flow rate of the liquid delivery pump does not reach the target flow rate based on the feedback control when obtaining the instruction value relative to the multiple flow rates.

8. A method for controlling a liquid delivery pump, the method being used to control the liquid delivery pump so that the flow rate of the liquid delivery pump disposed in a dialysate circuit of a blood purification device reaches a target flow rate, Feedforward control is performed, which is not based on the detection value of the flow detection unit that detects the flow rate of the liquid delivery pump. When a specified time has passed or a specified flow rate has been reached, the feedforward control is switched to feedback control based on the detection value of the flow detection unit.

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