Method for adjusting dialysate flow rate and hemodialyzer

Abstract

Provided are a method for adjusting a dialysate flow rate and a hemodialyzer capable of quickly completing adjustment of the dialysate flow rate to a desired flow rate. A method for adjusting a dialysate flow rate (100) includes: a pump control value determination step of determining a pump control value corresponding to a desired dialysate flow rate, on the basis of a calibration value indicating a correlation between the desired dialysate flow rate and a pump control value of a circulation pump (92); a pump operation step of operating the circulation pump with the pump control value determined in the pump control value determination step; a difference calculation step of obtaining a difference between a current dialysate flow rate and the desired dialysate flow rate; and a calibration value correction step of correcting the calibration value on the basis of the difference calculated in the difference calculation step.

Description

Method for Adjusting Dialysate Flow Rate and Hemodialysis Apparatus

[0001] The present invention relates to a method for adjusting the dialysate flow rate and a hemodialysis apparatus.

[0002] In a hemodialysis apparatus, it is required to adjust the dialysate flow rate according to the patient's condition and the difference in the dialysis treatment method. Patent Document 1 discloses a hemodialysis apparatus that adjusts the dialysate flow rate to a flow rate corresponding to the blood flow rate.

[0003] Japanese Patent Laid-Open No. 9-168587

[0004] However, in a conventional hemodialysis apparatus, it is difficult to quickly adjust the dialysate flow rate to a desired flow rate and complete the adjustment.

[0005] An object of the present invention is to provide a method for adjusting the dialysate flow rate and a hemodialysis apparatus that can quickly adjust and complete the dialysate flow rate to a desired flow rate.

[0006] The method for adjusting the dialysate flow rate of the present invention is a method for adjusting the dialysate flow rate in a hemodialysis apparatus including a dialysate circuit and a circulation pump provided in the dialysate circuit, and is based on a calibration value indicating a correlation between a desired dialysate flow rate and a pump control value of the circulation pump. A pump control value determination step for determining a pump control value corresponding to the desired dialysate flow rate, a pump operation step for operating the circulation pump with the pump control value determined in the pump control value determination step, a difference calculation step for obtaining a difference between the current dialysate flow rate and the desired dialysate flow rate, and a calibration value correction step for correcting the calibration value based on the difference calculated in the difference calculation step.

[0007] In the method for adjusting the dialysate flow rate of the present invention, the pump control value determination step, the pump operation step, the difference calculation step, and the calibration value correction step may be repeated until the difference is within a predetermined allowable range.

[0008] In the method for adjusting the dialysate flow rate of the present invention, the difference calculation step and the calibration value correction step may be executed when the circulation pump is operated with a new pump control value.

[0009] The method for adjusting the dialysate flow rate of the present invention may involve performing the difference calculation step at predetermined intervals, and if the difference calculated in the difference calculation step exceeds a predetermined value, the calibration value correction step may be performed.

[0010] The hemodialysis apparatus of the present invention comprises a dialysate circuit and a circulating pump provided in the dialysate circuit, wherein the output of the circulating pump changes according to a set pump control value, the pump control value is determined based on a calibration value that shows the correlation between a desired dialysate flow rate and the pump control value, and the apparatus comprises a flow rate calculation unit that calculates the dialysate flow rate of the dialysate circuit, and a correction value calculation unit that corrects the calibration value based on the difference between the dialysate flow rate calculated by the flow rate calculation unit and a desired dialysate flow rate corresponding to the set pump control value.

[0011] The hemodialysis apparatus of the present invention includes a correction value calculation unit and a correction value adjustment unit. The correction value adjustment unit may, with respect to the continuously calculated dialysate flow rate, adjust the ratio of the correction amount to the difference between the calculated dialysate flow rate and the desired dialysate flow rate when the circulation pump is operated with a pump control value determined based on the calibration value before correction, to the ratio of the correction amount to the difference between the calculated dialysate flow rate and the desired dialysate flow rate when the circulation pump is operated with a pump control value determined based on the calibration value after correction, when the relationship between the magnitudes of the calculated dialysate flow rate and the desired dialysate flow rate is reversed, in the next correction of the calibration value, make the ratio of the correction amount to the difference between the calculated dialysate flow rate and the desired dialysate flow rate smaller than the previous correction of the calibration value.

[0012] The hemodialysis apparatus of the present invention includes a correction value calculation unit which is outside the dialysate flow rate range determination unit which determines whether the difference between the current dialysate flow rate and the desired dialysate flow rate exceeds a predetermined range, and the correction value calculation unit may correct the calibration value if the dialysate flow rate range determination unit determines that it exceeds a predetermined value.

[0013] According to the present invention, it is possible to provide a method for adjusting the dialysate flow rate and a hemodialysis apparatus that can quickly adjust the dialysate flow rate to a desired flow rate.

[0014] Figure 1 is a diagram showing the overall configuration of a hemodialysis apparatus according to one embodiment of the present invention. Figure 2 is a diagram showing some extracted lines and valves of a hemodialysis apparatus according to one embodiment of the present invention. Figure 3 is a block diagram showing an overview of each part of the hemodialysis apparatus according to Embodiment 1 of the present invention. Figure 4 is a diagram showing an example of the display unit of Embodiment 1 of the present invention. Figure 5 is a diagram showing a linear equation in Embodiment 1 of the present invention. Figure 6 is a flowchart showing the processing flow of the dialysate flow rate adjustment method of this embodiment. Figure 7 is a diagram showing the change in the current dialysate flow rate due to correction. Figure 8 is a diagram showing the change in the current dialysate flow rate due to correction with a changed correction range. Figure 9 is a block diagram showing an overview of each part of a hemodialysis apparatus according to a modified example of an embodiment of the present invention. Figure 10 is a diagram showing an example of the display unit of Embodiment 2 of the present invention. Figure 11 is a diagram showing each linear equation in Embodiment 2 of the present invention. Figure 12 is a block diagram showing an overview of each part of a hemodialysis apparatus according to a modified example of an embodiment of the present invention. Figure 13 is a diagram showing an example of the timing of dialysate flow rate calculation.

[0015] (Embodiment 1) A preferred embodiment of the method for adjusting the dialysate flow rate and the personal hemodialysis apparatus 1 with a dialysate flow rate adjustment function according to Embodiment 1 of the present invention will be described with reference to the drawings. The personal hemodialysis apparatus 1 is a device that purifies the blood of patients with renal failure and drug poisoning, removes excess water from the blood, and replenishes water in the blood as needed, i.e., replaces fluid. The personal hemodialysis apparatus 1 is just one example of a hemodialysis apparatus, and the hemodialysis apparatus of the present invention is not limited to the personal hemodialysis apparatus 1.

[0016] The overall configuration of the personal hemodialysis machine 1 will be described with reference to Figure 1. Figure 1 is a diagram showing the overall configuration of the personal hemodialysis machine 1 of this embodiment. The personal hemodialysis machine 1 comprises a dialyzer 10, a blood circuit 20, a dialysate circuit 30, a replenishment fluid line 38, and a console 100. The console 100 is equipped with a part of the blood circuit 20, a part of the dialysate circuit 30, a heater 40, a drug solution pump 231, a replenishment fluid pump 39, a control unit 50, an operation unit 70, and a display unit 80.

[0017] In the personal hemodialysis machine 1, the dialysate is not supplied to the console 100 from an external source as pre-prepared dialysate, but rather is prepared in the console 100. The preparation of the dialysate in the console 100 will be explained later.

[0018] The dialyzer 10 comprises a cylindrical container body 11 and a dialysis membrane (not shown) housed inside the container body 11. The inside of the container body 11 is divided into a blood-side flow path and a dialysate-side flow path by the dialysis membrane. Neither of these is shown. The container body 11 has a blood inlet 111 and a blood outlet 112 that communicate with the blood-side flow path, and a dialysate inlet 113 and a dialysate outlet 114 that communicate with the dialysate-side flow path.

[0019] The blood circuit 20 comprises an arterial line 21, a venous line 22, and a drug line 23. An overflow line 24 may also be included. The arterial line 21, the venous line 22, and the drug line 23 are all primarily composed of flexible tubes through which liquid can flow.

[0020] The tubes constituting the arterial line 21, the venous line 22, and the drug line 23 are formed from flexible tubing such as polyvinyl chloride or silicone. The outer diameter of the tubing can be, for example, 5.5 mm, and the inner diameter can be, for example, 3.3 mm. The hardness of the tubing can be, for example, 50 to 85 according to JIS K7215.

[0021] One end of the arterial line 21 is connected to the artery of the person undergoing dialysis, i.e., the dialysis patient, and the other end is connected to the blood inlet 111 of the dialyzer 10.

[0022] A portion of the arterial line 21 is positioned in the console 100. A blood pump 212 is positioned in the console 100 in the area through which the arterial line 21 passes.

[0023] The blood pump 212 pumps out blood, priming fluid, and other fluids from inside the arterial line 21 by squeezing the tube that makes up the arterial line 21 with a roller.

[0024] One end of the venous line 22 is connected to the blood outlet 112 of the dialyzer 10, and the other end is connected to the subject's vein.

[0025] A venous chamber 222 is positioned in the middle of the venous line 22. The venous chamber 222 is located between the dialyzer 10 and the console 100 in the venous line 22. The venous chamber 222 stores a predetermined amount of blood, for example, 20 ml. A venous clamp 112d is also positioned between the venous chamber 222 and the patient-side end of the venous line 22.

[0026] The drug line 23 supplies the necessary drugs to the arterial line 21 during hemodialysis. One end of the drug line 23, the proximal end, is connected to a drug solution pump 231 that delivers the drugs, and the other end, the proximal end, is connected between the blood pump 212 and the dialyzer 10 in the arterial line 21.

[0027] If an overflow line 24 is provided, one end of the overflow line 24 is connected to the venous chamber 222 at its proximal end. The overflow line 24 is a line for discharging saline solution and air flowing through the venous line 22 to the outside during the priming process. An overflow clamp 241 is placed on the overflow line 24. The overflow clamp 241 opens and closes the flow path of the overflow line 24.

[0028] In the blood circuit 20, blood drawn from the subject's artery is pumped by a blood pump 212 through the arterial line 21 and introduced into the blood-side flow path of the dialyzer 10. The blood introduced into the dialyzer 10 is purified by the dialysate flowing through the dialysate circuit 30 (described later) via the dialysis membrane. The blood purified in the dialyzer 10 is returned to the subject's vein through the venous line 22.

[0029] In this embodiment, the dialysate circuit 30 is composed of a so-called sealed volume control type dialysate circuit 30. The dialysate circuit 30 includes a dialysate chamber 31, a stock solution supply line 32, a dialysate introduction line 33, a dialysate outlet line 34, a first drain line 35, a second drain line 36 as a drain line, a water removal / reverse filtration pump 37 as a pump, a circulation pump line 90, and a circulation pump 92. The dialysate circuit 30 in this embodiment includes a plurality of dialysate chambers as the dialysate chamber 31, such as a first dialysate chamber 31A and a second dialysate chamber 31B. In the following description, when there is no need to particularly distinguish between the first dialysate chamber 31A and the second dialysate chamber 31B, the first dialysate chamber 31A and the second dialysate chamber 31B together will simply be referred to as the dialysate chamber 31.

[0030] The dialysate chamber 31 comprises a rigid container 311 capable of holding a certain volume of dialysate, and a flexible diaphragm 312 that partitions the inside of the container 311. The certain volume can be, for example, 300 ml or more and 500 ml or less. The aforementioned flexible diaphragm is also called a diaphragm. The inside of the dialysate chamber is partitioned by the diaphragm 312 into a fluid supply section 313 and a drainage section 314.

[0031] The fluid supply and containment section 313 of the first dialysate chamber 31A is referred to as the first fluid supply and containment section 313A, and the fluid supply and containment section 313 of the second dialysate chamber 31B is referred to as the second fluid supply and containment section 313B. The drainage fluid containment section 314 of the first dialysate chamber 31A is referred to as the first drainage fluid containment section 314A, and the drainage fluid containment section 314 of the second dialysate chamber 31B is referred to as the second drainage fluid containment section 314B.

[0032] The base end of the concentrate supply line 32 is connected to an RO water tank, a concentrate A tank, and a concentrate B tank (not shown), and the tip end is connected to the dialysate chamber 31. The concentrate supply line 32 supplies RO water, concentrate A, and concentrate B, which are the raw materials for dialysate, to the first fluid supply storage section 313A and the second fluid supply storage section 313B of the dialysate chamber 31. When there is no need to distinguish between concentrate A and concentrate B, or when referring to both concentrate A and concentrate B, the terms concentrate or dialysate concentrate are used instead of concentrate A and concentrate B.

[0033] The dialysate introduction line 33 connects the dialysate chamber 31 to the dialysate inlet 113 of the dialyzer 10. The dialysate introduction line 33 introduces the dialysate contained in the first fluid supply section 313A and the second fluid supply section 313B of the dialysate chamber 31 into the dialysate side flow path of the dialyzer 10.

[0034] The dialysate outlet line 34 connects the dialysate outlet 114 of the dialyzer 10 to the dialysate chamber 31. The dialysate outlet line 34 leads the dialysate discharged from the dialyzer 10 to the first drainage container 314A and the second drainage container 314B of the dialysate chamber 31.

[0035] The base end of the first drainage line 35 is connected to the dialysate chamber 31 and discharges the dialysate contained in the first drainage storage section 314A and the second drainage storage section 314B.

[0036] The second drainage line 36 has its proximal end connected to the dialysate outlet line 34 and discharges the dialysate flowing through the dialysate outlet line 34.

[0037] The water removal / reverse filtration pump 37 is located in the second drain line 36. The water removal / reverse filtration pump 37 is composed of a pump that is driven to deliver dialysate inside the second drain line 36 in a direction that flows towards the discharge side (forward direction) and in a direction that flows towards the dialysate outlet line 34 (reverse direction). The direction in which dialysate flows towards the discharge side is called the water removal direction. The direction in which dialysate flows towards the dialysate outlet line 34 is called the reverse filtration direction.

[0038] The circulation pump line 90 is positioned to bypass the dialysate outlet line 34.

[0039] The circulation pump 92 is located in the circulation pump line 90. The circulation pump 92 can facilitate the flow of dialysate in the dialysate circuit 30, among other things.

[0040] The heater 40 heats the dialysate flowing through the dialysate circuit 30 to a predetermined temperature.

[0041] The replenishing fluid line 38 is a line for directly supplying dialysate as replenishing fluid to the blood circuit 20. The upstream side of the replenishing fluid line 38 is connected between the dialysate chamber 31 in the dialysate introduction line 33 of the dialysate circuit 30 and the dialysate inlet 113 of the dialyzer 10.

[0042] A clamp for the replenishing fluid is provided on the replenishing fluid line 38. The clamp for the replenishing fluid provided on the replenishing fluid line 38 in pre-dilution is the replenishing fluid clamp 381, and the clamp for the replenishing fluid provided on the replenishing fluid line 38 in post-dilution is the replenishing fluid clamp 382.

[0043] As shown by the solid line in FIG. 1, when the downstream side of the replenishing fluid line 38 is connected between the blood pump 212 and the dialyzer 10 in the arterial side line 21, it is pre-dilution mode hemodiafiltration. As shown by the dashed line in FIG. 1, when the downstream side of the replenishing fluid line 38 is connected to the venous side chamber 222 in the venous side line 22, it is post-dilution mode hemodiafiltration.

[0044] The control unit 50 is constituted by an information processing device, for example, a computer. By executing a control program in the information processing device, the operation of the personal hemodialysis device 1 as a whole is controlled. The control unit 50 controls and operates the operation of the personal hemodialysis device 1 by executing control programs for various processes. Specifically, the control unit 50 controls the operations of various pumps, clamps, and the heater 40 etc. arranged in the blood circuit 20 and the dialysate circuit 30, and executes various processes performed by the personal hemodialysis device 1. The various processes include, for example, a priming process, a blood removal process, a dialysis process, a fluid replenishment process, a blood return process, etc.

[0045] In various processes of the personal hemodialysis device 1 of the present embodiment, for example, the priming process, the blood removal process, the dialysis process, and the blood return process are executed in this order, and the execution time of all these processes takes about 4 to 5 hours.

[0046] The priming process is a preparatory process for cleaning and purifying the blood circuit 20 and the dialyzer 10. The blood extraction process is a process of filling the patient's blood into the blood circuit 20 after puncture and performing extracorporeal circulation. The dialysis process is a process that is performed following the blood extraction process and purifies the blood by dialysis. The fluid infusion process is a process of performing rapid fluid infusion during dialysis treatment when blood pressure drops or the like. The blood return process is a process of returning the blood in the blood circuit 20 to the patient's body.

[0047] As described above, an example of the personal hemodialysis device 1 has been described. Hereinafter, referring to FIG. 2, the arrangement of the lines and valves arranged in the console 100 of the present embodiment will be described in more detail. FIG. 2 is a diagram showing a partial extraction of the lines and valves arranged in the console 100. FIG. 2 and each of the figures described below do not show all of the lines, valves, and components arranged in the console 100. FIG. 2 and each of the figures described below show the part related to the dialysate chamber 31 as the center. Also, there are parts where the configuration is different between the personal hemodialysis device 1 described with reference to FIG. 1 and the personal hemodialysis device 1 described with reference to FIG. 2 and the like below. In any configuration, the configurations in which the technology of the present disclosure can be implemented are included in the embodiments of the present disclosure.

[0048] (Configuration related to preparation of dialysate) The configuration related to the preparation of dialysate in the personal hemodialysis device 1 will be described. In the present embodiment, the dialysate is prepared in the console 100. Specifically, the dialysate is prepared in each dialysate chamber 31, and the prepared dialysate is stored in the dialysate chamber 31. The dialysate is prepared, for example, by mixing RO water, stock solution A, and stock solution B.

[0049] The personal hemodialysis machine 1 includes an RO water line L10, a degassing pump P1, a first solenoid valve SV1, and a third solenoid valve SV3 as components for preparing the dialysate. In Figure 2 and other figures, open valves are drawn in white and closed valves are drawn in black. First, RO water is supplied from one end of the RO water line L10. The other end of the RO water line L10 is connected to each dialysate chamber 31 via a solenoid valve. More specifically, the other end of the RO water line L10 branches into two at the junction J14 before being connected to each dialysate chamber 31. One of the branches is connected to the first fluid supply container 313A via the first solenoid valve SV1. The other branch is connected to the second fluid supply container 313B via the third solenoid valve SV3.

[0050] The degassing pump P1 is installed in the RO water line L10.

[0051] The personal hemodialysis machine 1 further includes a stock solution line L11, a stock solution tank A TA, a stock solution tank B TB, a solenoid valve SVA for stock solution A, a solenoid valve SVB for stock solution B, and a stock solution pump P2.

[0052] One end of the concentrate line L11 is connected to concentrate tank A TA and concentrate tank B TB. More specifically, concentrate tank A TA is connected to one end of concentrate line L11 via solenoid valve SVA for concentrate A, and concentrate tank B TB is connected via solenoid valve SVB for concentrate B. The point in concentrate line L11 where concentrate tank A TA and concentrate tank B TB are connected is called the junction point J16.

[0053] The other end of the stock solution line L11 is connected to the upstream side of the junction point J14 in the RO water line L10. The point in the RO water line L10 where the other end of the stock solution line L11 is connected is called the junction point J12.

[0054] The concentrate pump P2 is located downstream of the junction point J16 in the concentrate line L11.

[0055] The personal hemodialysis machine 1 is further equipped with an auxiliary RO water line L12 and an auxiliary line solenoid valve SVC.

[0056] One end of the auxiliary RO water line L12 is connected to the RO water line L10 downstream of the degassing pump P1 and upstream of the connection point J12. The point on the RO water line L10 where the auxiliary RO water line L12 is connected is called the connection point J10.

[0057] The other end of the auxiliary RO water line L12 is connected to the joint point J16.

[0058] The auxiliary line solenoid valve SVC is installed in the auxiliary RO water line L12.

[0059] The dialysis fluid is prepared, for example, by injecting concentrate A, concentrate B, and RO water into a dialysis fluid chamber 31 with a volume of 300 ml in a set ratio. The injection is carried out in the order of RO water, concentrate A, RO water, concentrate B, and RO water. If concentrate A and concentrate B are mixed directly, they may react and form compounds. During the injection process of concentrate A and concentrate B, care must be taken to prevent direct mixing of concentrate A and concentrate B within the line. In other words, contact between concentrate A and concentrate B within the line must be avoided.

[0060] The preparation of the dialysate is completed when predetermined amounts of each fluid are injected into the dialysate chamber 31 and mixed together.

[0061] The method for adjusting the dialysate flow rate and the personal hemodialysis apparatus 1 of Embodiment 1 will be described below. Here, dialysate flow rate refers to the flow rate of dialysate in the dialysate circuit 30.

[0062] Referring to Figure 3, the control unit 50 and other components of the personal hemodialysis machine 1 of Embodiment 1 will be described in more detail. Figure 3 is a block diagram showing the various parts of the console 100. As shown in Figure 1, the console 100 includes a control unit 50, an operation unit 70, and a display unit 80.

[0063] The display unit 80 can be, for example, a liquid crystal display. The display unit 80 may also have a touch panel. The display unit 80 can display the set value of the dialysate flow rate and the current dialysate flow rate, etc.

[0064] The dialysate flow rate that the user wants to set is called the desired dialysate flow rate. The user can input the desired dialysate flow rate from the control unit 70. The input method can be by pressing a button on the control unit 70 or by touching a touch panel on the control unit 70. The control unit 70 may be integrated with the display unit 80.

[0065] The desired dialysate flow rate value entered by the user via the control unit 70 or the like is called the dialysate flow rate setting value.

[0066] The control unit 50 includes a calibration value storage unit 501, a pump control unit 503, a calibration value calculation unit 505, a correction value calculation unit 507, and a flow rate calculation unit 509.

[0067] The calibration value calculation unit 505 is the part that calculates the calibration value. The calibration value is a relationship between the desired dialysate flow rate and the pump control value. The calibration value calculation unit 505 calculates the desired dialysate flow rate, the pump control value, and the relationship between them. The pump control value will be explained later.

[0068] The calibration value storage unit 501 is the part that stores the calibration value calculated by the calibration value calculation unit 505.

[0069] The flow rate calculation unit 509 is the part that calculates the current dialysate flow rate. The desired dialysate flow rate is a set value, while the current dialysate flow rate is the actual flow rate of the dialysate.

[0070] The correction value calculation unit 507 is responsible for calculating the correction value of the pump control value. The correction value calculation unit 507 calculates the correction value of the pump control value from the difference between the set value of the dialysate flow rate and the current dialysate flow rate calculated by the flow rate calculation unit 509. In other words, the correction value calculation unit 507 calculates the correction value of the pump control value from the difference between the desired dialysate flow rate and the current dialysate flow rate.

[0071] Calculating a correction value for pump control values ​​means, for example, determining the range by which to correct the calibration value.

[0072] The pump control unit 503 controls the operation of the circulation pump 92 based on calibration values ​​and correction values. Specifically, pump control values ​​are determined based on calibration values ​​and correction values. The determined pump control values ​​are stored, for example, in the calibration value storage unit 501. The pump control unit 503 controls the operation of the circulation pump 92 and controls the pump discharge amount using the pump control values ​​stored in the calibration value storage unit 501. The specific functions of each part of the control unit 50 will be described in order below.

[0073] The general outline of the method for adjusting the dialysate flow rate in this embodiment is as follows: The calibration values ​​for the pump control value and the dialysate flow rate are stored in the console 100 in advance.

[0074] The pump control value is a value that defines the output of the circulation pump 92. The pump control value can be, for example, a PWM (Pulse Width Modulation) signal. However, the pump control value is not limited to a PWM signal; it can also be a value other than a PWM signal, such as a current value, a voltage value, or an analog signal.

[0075] The storage of calibration values ​​in the console 100, that is, the input of calibration values ​​to the calibration value storage unit 501, can be performed, for example, during the manufacturing of the console 100. Alternatively, calibration values ​​may be determined by user instructions, and the determined calibration values ​​may be stored in the calibration value storage unit 501.

[0076] When using the console 100, the dialysate flow rate is adjusted using the stored calibration values. For example, the dialysate flow rate is adjusted so that the current dialysate flow rate matches the dialysate flow rate entered into the control unit 70, i.e., the desired dialysate flow rate.

[0077] Specifically, based on the calibration values, the pump control values ​​corresponding to the desired dialysate flow rate are determined. The dialysate flow rate is calculated when the circulation pump is operated with the determined pump control values. The difference between the calculated dialysate flow rate, i.e., the current dialysate flow rate, and the desired dialysate flow rate is determined. Based on the obtained difference, the calibration values ​​are corrected by the difference correction.

[0078] Then, a new pump control value is determined based on the differentially corrected calibration value, and the circulating pump is operated using this new pump control value. This procedure makes it possible to quickly adjust the dialysate flow rate.

[0079] Furthermore, if there is a difference between the current dialysate flow rate after differential correction and the desired dialysate flow rate, the calibration value may be further differentially corrected. This allows the current dialysate flow rate to quickly approach the desired flow rate. A more detailed explanation follows.

[0080] Embodiment 1 involves calculating calibration values ​​at two points. That is, the calibration value between the desired dialysate flow rate and the pump control value is determined based on two points and shown by a single straight line. The circulation pump 92 is assumed to be, for example, a gear-type pump. The pump control value is assumed to be, for example, a PWM signal. By inputting the PWM signal to the circulation pump 92, voltage control or current control is performed in the electronic circuit of the circulation pump 92. This voltage control or current control can change the pump discharge amount of the circulation pump 92.

[0081] The personal hemodialysis device 1 of Embodiment 1 is assumed to be a system in which the PWM signal and the dialysate flow rate have a linear relationship. Currently, the dialysate flow rate becomes low when the pump control value is decreased, and high when it is increased.

[0082] Referring to Figure 4, Embodiment 1 will be described using the example of a case where the calibration value is determined by user instructions. Figure 4 is a diagram showing an example of the display on the display unit 80 in this embodiment. For example, the calibration value is calculated when the user presses the adjustment start button on the display unit 80.

[0083] The calibration value calculation unit 505 sets two points for dialysate flow rate: low flow rate 1 and high flow rate 1. The calibration value calculation unit 505 calculates calibration values ​​for the pump control value and dialysate flow rate at these two points: low flow rate 1 and high flow rate 1.

[0084] As calibration coordinate value 1, pump control value 1 is determined, and the current dialysate flow rate calculated using pump control value 1 is set as low flow rate 1. Then, similarly, as calibration coordinate value 2, pump control value 2 is determined, and the current dialysate flow rate calculated using pump control value 2 is set as high flow rate 1.

[0085] The derivation of calibration values ​​between the pump control value and the current dialysate flow rate will be explained. As a result of setting the low flow rate 1 and high flow rate 1 as described above, calibration coordinate values ​​1 (pump control value 1, low flow rate 1) and calibration coordinate values ​​2 (pump control value 2, high flow rate 1) are obtained. Then, from calibration coordinate values ​​1 and calibration coordinate values ​​2, a linear equation 1 (Y = a・X + b) between two points can be calculated. Figure 5 shows the linear equation 1 (Y = a・X + b). The calibration value storage unit 501 stores this linear equation 1 as the calibration value.

[0086] (Flow Rate Adjustment) Flow rate adjustment will now be explained. When the desired dialysate flow rate (Y) is set in the control unit 70, the pump control value (X) is determined from the linear equation 1 (Y = a・X + b) stored in the calibration value storage unit 501.

[0087] The pump control value (X) determined based on linear equation 1 is input to the circulation pump 92. This controls the circulation pump 92, and the pump discharge rate of the circulation pump 92 changes.

[0088] The flow rate calculation unit 509 calculates the current dialysate flow rate (Y'), which is the actual flow rate of the dialysate. Since the current dialysate flow rate (Y') is the flow rate obtained using calibration values, it will be close to the desired dialysate flow rate (Y).

[0089] Next, linear equation 1 is corrected based on the difference (c) between the desired dialysate flow rate (Y) and the current dialysate flow rate (Y'). For example, linear equation 1 is shifted so that the difference (c) becomes zero. However, if the difference (c) is not large, the linear equation 1 may not be corrected, and the flow rate adjustment control may be terminated.

[0090] For example, if the current dialysate flow rate (Y') is within a predetermined range relative to the desired dialysate flow rate (Y), the flow rate adjustment control can be terminated. For example, if the current dialysate flow rate is within the range of desired dialysate flow rate - 5 mL / min ≤ current dialysate flow rate ≤ desired dialysate flow rate + 5 mL / min, no further flow rate adjustment control can be performed. In other words, if the current dialysate flow rate (Y') is within a predetermined tolerance range relative to the desired dialysate flow rate (Y), the flow rate adjustment control can be terminated.

[0091] In contrast, if the current dialysate flow rate (Y') is not within a predetermined tolerance range relative to the desired dialysate flow rate (Y), the flow rate adjustment control can be continued. For example, if the current dialysate flow rate is not within the range of desired dialysate flow rate - 5 mL / min ≤ current dialysate flow rate ≤ desired dialysate flow rate + 5 mL / min, the flow rate adjustment control can be continued.

[0092] Note that 5 mL / min in the above formula is an example. The allowable range of deviation between the current dialysate flow rate (Y') and the desired dialysate flow rate (Y) can be set arbitrarily.

[0093] The process for continuing flow rate adjustment control will now be explained. The correction value calculation unit 507 calculates the difference (c) between the desired dialysate flow rate (Y) and the current dialysate flow rate (Y'). Then, the calibration value calculation unit 505 shifts linear equation 1 by the difference (c) to obtain the calibration value Y = a・X' + b + c. Next, the correction value calculation unit 507 corrects the pump control value from (X) to (X') and inputs the corrected pump control value X' back into the pump control unit 503.

[0094] Then, the same procedure is repeated until the current dialysate flow rate (Y') calculated by the flow rate calculation unit 509 falls within the acceptable range of deviation from the desired dialysate flow rate (Y).

[0095] The flow rate adjustment control is terminated when the current dialysate flow rate satisfies the following equation, for example: desired dialysate flow rate - 5 mL / min ≤ current dialysate flow rate ≤ desired dialysate flow rate + 5 mL / min. In other words, the flow rate adjustment control is terminated when the current dialysate flow rate falls within the acceptable deviation range from the desired dialysate flow rate. If the current dialysate flow rate (Y') calculated by the flow rate calculation unit 509 is not within the acceptable deviation range from the desired dialysate flow rate (Y), the same flow rate adjustment control procedure is repeated.

[0096] As described above, by correcting the calibration values ​​between the desired dialysate flow rate (Y) and the pump control value (X), and bringing them closer to the actual relationship between the pump control value and the dialysate flow rate, it becomes possible to quickly adjust the dialysate flow rate to the desired flow rate.

[0097] Referring to Figure 6, the procedure for adjusting the dialysate flow rate of this embodiment will be described. Figure 6 is a flowchart showing the processing flow of the dialysate flow rate adjustment method of this embodiment. In Figure 6 and the following description, S1 means step 1. The same applies to the other steps. Note that the flow shown in Figure 6 is just one example of the dialysate flow rate adjustment method of this embodiment. The dialysate flow rate adjustment method of this embodiment is not limited to the flow shown in Figure 6 and can be modified in various ways.

[0098] (S1) S1 is the calibration value storage step. The calibration value is the calibration value between the pump control value and the desired dialysate flow rate. The calibration value is calculated by the calibration value calculation unit 505 and stored in the calibration value storage unit 501. The calibration value storage step may be performed during the manufacture of the personal hemodialysis machine 1, or it may be performed at the request of the user.

[0099] (S2) S2 is the first circulating pump operation step. In S2, the circulating pump is operated with a pump control value calculated using a calibration value for the desired dialysate flow rate.

[0100] (S3) S3 is the first difference calculation step. In S3, the difference (c) between the current dialysate flow rate (Y'), which is the actual flow rate of the dialysate, and the desired dialysate flow rate (Y) is calculated.

[0101] (S4) S4 is a calibration value correction step. In S4, the calibration value is corrected based on the difference (c). For example, the calibration value between the pump control value and the dialysate flow rate, which are calibration values, is shifted by an amount based on the difference (c). For example, the calibration value is corrected by shifting the calibration value so that the difference (c) becomes zero.

[0102] (S5) S5 is the second circulation pump operation step. In S5, a new pump control value (X') obtained from the corrected calibration value is input to the pump control unit 503 and the circulation pump is operated.

[0103] (S6) S6 is the second difference calculation step. In S6, the difference (c) between the current dialysate flow rate (Y'), which is the actual flow rate of dialysate based on the new pump control value (X'), and the desired dialysate flow rate (Y).

[0104] (S7) S7 is the difference determination step. In S7, it is determined whether the difference (c) calculated in S6 is within the acceptable range. If the difference (c) is not within the acceptable range, the step returns to S4. In S4, the calibration value is corrected again, and steps S5 to S7 are repeated. If the difference (c) is within the acceptable range, the flow of the dialysate flow rate adjustment method of this embodiment is completed.

[0105] (Other examples of adjusting the correction amount) Next, other examples of adjusting the correction amount will be described. In the above description, linear equation 1 was corrected based on the difference (c) between the desired dialysate flow rate (Y) and the current dialysate flow rate (Y'). Specifically, linear equation 1 was corrected from (Y = a * X + b) to (Y = a * X + b + c). However, the method of correction is not limited to this example. For example, (+c) can also be (+1 / 2c) or (+1 / 4c), etc.

[0106] Figure 7 is an illustrative diagram showing a case where rapid adjustment of the flow rate is difficult with the (+c) correction. The horizontal axis L101 in Figure 7 represents the desired dialysate flow rate. The arrow + in Figure 7 indicates that the current dialysate flow rate is greater than the desired dialysate flow rate, and the arrow - indicates that the current dialysate flow rate is less than the desired dialysate flow rate.

[0107] Point P101 in Figure 7 shows the dialysate flow rate based on the calibration value before correction. Point P102 shows the dialysate flow rate based on the calibration value after the first correction. The first correction refers to the correction based on the value at point P101. Point P103 shows the dialysate flow rate based on the calibration value after the second correction. The second correction refers to the correction based on the value at point P102.

[0108] As shown in Figure 7, the dialysate flow rate at point P101 is greater than the desired dialysate flow rate. The dialysate flow rate at point P102 is less than the desired dialysate flow rate. In other words, point P102 is a transition from point P101 to point P102, exceeding the horizontal axis L101 which represents the desired dialysate flow rate. The same applies to point P103. Point P103 is a transition from point P102 to point P103, exceeding the horizontal axis L101.

[0109] If the corrected dialysate flow rate changes beyond horizontal axis L101 from the uncorrected dialysate flow rate, it means the correction range is too large. When the correction range is too large, it is usually difficult to reduce the difference (c). As a result, rapid adjustment of the dialysate flow rate becomes difficult.

[0110] Therefore, if the correction range is deemed too large, it may be possible to reduce the correction range.

[0111] Figure 8 shows the change in dialysate flow rate when the correction range is reduced. The horizontal axis L101, the + arrows, and the - arrows have the same meaning as in Figure 7. Point P101 in Figure 8 is the same point as point P101 in Figure 7. Point P111 is the point where the correction range, i.e., the range of translation, is halved compared to point 102 in Figure 7. Similarly, point 112 is the point where the correction range, i.e., the range of translation, is halved compared to point 103 in Figure 7. Point 103 in Figure 7 is about the same distance from the horizontal axis L101 as point P101, whereas point P112 in Figure 8 is located almost on the horizontal axis L101. In other words, point P112 is approximately the desired dialysate flow rate.

[0112] In this way, by reducing the correction range by half each time a correction is made, the dialysate flow rate can be quickly adjusted to the desired dialysate flow rate.

[0113] In other words, if the current dialysate flow rate is calculated to exceed (or cross over) the desired flow rate each time the dialysate flow rate is adjusted, adjusting the dialysate flow rate may take time. In such cases, the amount of parallel shift is reduced by, for example, half each time a correction is made. That is, the first correction is made by half, the second correction by quarter, and so on. This allows the dialysate flow rate to be quickly adjusted to the desired flow rate.

[0114] Referring to Figure 9, the configuration of the control unit 50 when adjusting the correction amount described above will be explained. Figure 9 is a block diagram showing an overview of the various parts of the hemodialysis machine. The following explanation will describe matters that differ from those previously explained with reference to Figure 3. Matters that are not specifically explained can be the same as those shown in Figure 3.

[0115] In the control unit 50, when adjusting the correction amount, the correction value calculation unit 507 includes a correction value adjustment unit 511. The correction value adjustment unit 511 further adjusts the correction value calculated by the correction value calculation unit 507 using the method described above. Specifically, for example, if the current dialysate flow rate after the first correction changes from the current dialysate flow rate before correction to a desired dialysate flow rate, the correction value adjustment unit 511 can adjust the width of the second correction to, for example, half of the normal amount. A change exceeding the desired dialysate flow rate refers to, for example, a change from the positive side to the negative side of the desired dialysate flow rate, and a change from the negative side to the positive side of the desired dialysate flow rate. Also, adjusting the width of the correction to, for example, half of the normal amount means, for example, setting the width c of the parallel shift to 1 / 2c.

[0116] The criteria for determining whether the dialysate flow rate has changed beyond the desired level, as described above, are illustrative examples. These criteria can be set as appropriate. Furthermore, the 1 / 2 ratio used when adjusting the correction value is illustrative; the adjustment ratio for the correction value can be set as appropriate.

[0117] Furthermore, even when adjusting the correction amount, if the difference falls within a predetermined allowable range, the differential correction, i.e., the flow rate adjustment control, can be terminated, just as in the case where no adjustment is made to the correction amount.

[0118] (Embodiment 2) The method for adjusting the dialysate flow rate and the personal hemodialysis device 1 of Embodiment 2 will be described with reference to Figures 10 and 11. Embodiment 1 and Embodiment 2 differ in the number of points used for calibration. Embodiment 1 used two points for calibration. In contrast, Embodiment 2 uses four points for calibration. The following description will focus on the differences between Embodiment 2 and Embodiment 1. Matters not specifically described for Embodiment 2 can be the same as in Embodiment 1.

[0119] Depending on the configuration of the console 100 and the configuration of the personal hemodialysis machine 1, the relationship between pump control values ​​such as PWM signals and dialysate flow rate may not be linear. For example, in devices with many components in the dialysate line, such as personal hemodialysis machines, the relationship between pump control values ​​and dialysate flow rate may not be linear.

[0120] In personal hemodialysis machines, components such as those for mixing RO water, concentrate A, and concentrate B may be installed in the dialysate line. In such cases, the relationship between the pump control value and the dialysate flow rate is not linear.

[0121] If the relationship between the pump control value and the dialysate flow rate is not linear, it is preferable to perform calibration, that is, determination of the calibration value, using more than two points, such as four points, rather than based on two points as in Embodiment 1. Embodiment 2 shows an example of determining the calibration value using four points.

[0122] Figure 10 shows an example of the display of the display unit 80 in Embodiment 2. As shown in Figure 10, in Embodiment 2, the calibration value is determined using four calibration coordinate values, from calibration coordinate value 1 to calibration coordinate value 4.

[0123] The dialysate flow rate is set using four calibration points: low flow rate 1, medium flow rate 1, medium flow rate 2, and high flow rate 1. Calibration coordinate value 1 corresponds to low flow rate 1, calibration coordinate value 2 corresponds to medium flow rate 1, calibration coordinate value 3 corresponds to medium flow rate 2, and calibration coordinate value 4 corresponds to high flow rate 1. In the personal hemodialysis machine 1 of Embodiment 2, the calculated dialysate flow rate becomes low when the pump control value is small, and high when it is large. The range at which the dialysate flow rate changes from a given pump control value has been determined through prior experiments.

[0124] Similar to Embodiment 1, the calibration values, i.e., the calculation of each linear equation, can be initiated by, for example, the user pressing the adjustment start button on the display unit 80.

[0125] Specifically, first, pump control value 1 is determined as calibration coordinate value 1. The dialysate flow rate calculated at that time is set as low flow rate 1. After that, pump control value 2 is determined as calibration coordinate value 2. The dialysate flow rate calculated at that time is set as medium flow rate 1. Similarly, pump control value 3 and medium flow rate 2 are set as calibration coordinate value 3, and high flow rate 1 is set as calibration coordinate value 4.

[0126] Figure 11 shows the calibration results in Embodiment 2. As shown in Figure 11, in Embodiment 2, the calibration values ​​are determined at four points, so three linear equations are obtained. From calibration coordinate value 1 (pump control value 1, low flow rate 1) and calibration coordinate value 2 (pump control value 2, medium flow rate 1), a linear equation between two points (Y1 = a1・X + b1) can be calculated. Similarly, from calibration coordinate value 2 (pump control value 2, medium flow rate 1) and calibration coordinate value 3 (pump control value 3, medium flow rate 2), linear equation 2 (Y2 = a2・X + b2) can be calculated. Furthermore, from calibration coordinate value 3 (pump control value 3, medium flow rate 2) and calibration coordinate value 4 (pump control value 4, medium flow rate 1), linear equation 3 (Y3 = a3・X + b3) can be calculated. The calibration value storage unit 501 stores linear equations 1 to 3 as calibration values.

[0127] Here, the pump control value that corresponds to the user's desired dialysate flow rate can be calculated from the minimum values ​​of Y1, Y2, and Y3. In other words, the pump control value Y4 is Y4 = min(Y1, Y2, Y3). Y4 is one of Y1, Y2, or Y3, and these values ​​are stored as calibration values ​​in the calibration value storage unit 501.

[0128] As described above, the relationship between the pump control value and the dialysate flow rate is obtained based on linear formula Y1 for low flow rate 1 to medium flow rate 1, linear formula Y2 for medium flow rate 1 to medium flow rate 2, and linear formula Y3 for medium flow rate 2 to high flow rate 1.

[0129] (Flow Rate Adjustment) Flow rate adjustment in Embodiment 2 will now be described. When a desired dialysate flow rate (Y) is set, X is set as the pump control value from the stored value Y4 in the calibration value storage unit 501. By inputting this to the circulation pump 92, the circulation pump 92 is controlled.

[0130] When the pump control value (X) is input, the pump discharge rate changes, and the flow rate calculation unit 509 calculates the current dialysate flow rate (Y'). Since the dialysate flow rate (Y') is a value obtained using calibration values, it will be close to the desired dialysate flow rate (Y).

[0131] Therefore, for example, if the desired dialysate flow rate - 10 mL / min ≤ current dialysate flow rate ≤ desired dialysate flow rate + 10 mL / min, the flow rate adjustment control can be terminated.

[0132] If the current dialysate flow rate does not satisfy the above relationship, the correction value calculation unit 507 calculates the difference (c) between the desired dialysate flow rate (Y) and the current dialysate flow rate (Y'). Then, Y1, Y2, and Y3 are each shifted by the difference, i.e., the difference (c) (Y1 = a1・X + b1 + c, Y2 = a2・X + b2 + c, Y3 = a3・X + b3 + c).

[0133] After translating each linear equation, Y4 is calculated from Y4min(Y1, Y2, Y3) in the same way as before the translation. The corrected pump control value (X') obtained from the translated equation is input to the control pump again. This operation is repeated until the current dialysate flow rate falls within the desired dialysate flow rate range.

[0134] For example, if the current dialysate flow rate satisfies the following equation: Desired dialysate flow rate - 10 mL / min ≤ Current dialysate flow rate ≤ Desired dialysate flow rate + 10 mL / min, then the flow rate adjustment control can be terminated. In this way, the current dialysate flow rate can be quickly adjusted to the desired dialysate flow rate.

[0135] Furthermore, the adjustment of the correction amount described in Embodiment 1, that is, setting the correction amount to, for example, 1 / 2, can also be suitably applied to Embodiment 2.

[0136] (Modifications) A method for adjusting the dialysate flow rate and modifications of the personal hemodialysis machine 1 will be described with reference to Figures 12 and 13. Figure 12 is a block diagram showing an overview of the parts of a hemodialysis machine of a modified embodiment of the present invention. Figure 13 is a diagram showing an example of the timing for calculating the dialysate flow rate. The modifications described below can be applied regardless of whether they are Embodiment 1 or Embodiment 2.

[0137] In Embodiments 1 and 2, flow rate adjustment can be performed, for example, when the user presses the adjustment start switch on the display unit 80, or when the set value of the dialysate flow rate is changed from the operation unit 70 or the like.

[0138] This flow rate adjustment may be performed automatically, for example, when the current dialysate flow rate > desired dialysate flow rate + 20 mL / min, or when the current dialysate flow rate < desired dialysate flow rate - 20 mL / min, or when the above conditions persist for a certain period of time or longer.

[0139] In this case, the correction value is automatically calculated by the correction value calculation unit 507 without any user intervention. Then, the circulation pump 92 is controlled to perform the flow rate adjustment described above. This adjusts the current dialysate flow rate to a value close to the desired dialysate flow rate.

[0140] Figure 12 shows the configuration of the control unit 50 in a modified example. Figure 12 is a block diagram illustrating the outline of each part of a modified personal hemodialysis machine 1 according to an embodiment of the present invention. As shown in Figure 12, in the modified control unit 50, the correction value calculation unit 507 includes a dialysate flow rate range out-of-range determination unit 513. The dialysate flow rate range out-of-range determination unit 513 is a determination unit that determines when the difference between the current dialysate flow rate and the desired dialysate flow rate has become large. More specifically, the dialysate flow rate range out-of-range determination unit 513 determines when the difference between the current dialysate flow rate and the desired dialysate flow rate has become large enough to fall outside a predetermined range.

[0141] The dialysate flow rate range detection unit 513 can be, for example, a flow meter installed in the dialysate flow path. However, the configuration of the dialysate flow rate range detection unit 513 is not limited to a flow meter. The dialysate flow rate range detection unit 513 only needs to be capable of determining that the dialysate flow rate is outside a predetermined range.

[0142] If the dialysate flow rate range determination unit 513 determines that the dialysate flow rate is outside a predetermined range, the correction value calculation unit 507 automatically starts calculating the correction value as described above.

[0143] Referring to Figure 13, another example of calculating the dialysate flow rate will be explained. As shown in Figures 1 and 2, when the personal hemodialysis machine 1 uses two dialysate chambers 31, the dialysate flow rate can be calculated from the switching time between the dialysate chambers 31. The dialysate flow rate is calculated at the timing when the two dialysate chambers 31 switch. The timing of the dialysate chamber 31 switch can be determined by the fact that the dialysate stops flowing in the dialysate flow path of one of the dialysate chambers 31. Then, at the timing when the dialysate chambers 31 switch, the dialysate flow rate is calculated, and correction control for flow rate adjustment is performed at that time. The dialysate flow rate can be calculated based on the volume of the dialysate chamber 31 and the time until the switch. After the dialysate chamber 31 switches, the dialysate flow rate is calculated again at the timing when the dialysate chamber 31 switches again. By repeating this, it is possible to control the dialysate flow rate accurately and quickly.

[0144] The control of the dialysate flow rate will be explained based on Figure 13. The horizontal axis of Figure 13 represents time (t). First, at time T1, the desired dialysate flow rate is set. Then, the circulation pump is controlled using a pump control value based on calibration values. After that, the first dialysate chamber operates (CV1-1), followed by the second dialysate chamber (CV2-1). At the time when the second dialysate chamber has finished operating, i.e., at time T2, the current dialysate flow rate is calculated. At this time, the dialysate flow rate may also be calculated by averaging the dialysate flow rates of the two dialysate chambers. By averaging the dialysate flow rates of the two dialysate chambers, a more accurate dialysate flow rate can be calculated.

[0145] If the difference between the current dialysate flow rate and the desired dialysate flow rate is within a predetermined range, the flow rate adjustment is complete.

[0146] If the difference between the current dialysate flow rate and the desired dialysate flow rate is not within a predetermined range, a correction value is calculated. Then, the pump is controlled using the corrected pump control value. Specifically, the first dialysate chamber operates again (CV1-2), followed by the second dialysate chamber operating again (CV2-2). At the timing when the second dialysate chamber has finished operating, i.e., time T3, the current dialysate flow rate is calculated.

[0147] If the difference between the current dialysate flow rate and the desired dialysate flow rate is within a predetermined range, the flow rate adjustment is complete. If the difference between the current dialysate flow rate and the desired dialysate flow rate is not within the predetermined range, the correction value is calculated again. Then, the pump is controlled using the corrected pump control value. This process is repeated until the difference between the current dialysate flow rate and the desired dialysate flow rate falls within the predetermined range.

[0148] The embodiments of the present invention have been described above. The present invention is not limited to the embodiments described above, and various modifications, variations, and combinations are possible.

[0149] <1> A method for adjusting the dialysate flow rate in a personal hemodialysis machine 1 comprising a dialysate circuit 30 and a circulation pump 92 provided in the dialysate circuit 30, comprising: a pump control value determination step of determining a pump control value corresponding to the desired dialysate flow rate based on a calibration value that shows the correlation between the desired dialysate flow rate and the pump control value of the circulation pump; a pump operation step of operating the circulation pump with the pump control value determined in the pump control value determination step; a difference calculation step of calculating the difference between the current dialysate flow rate and the desired dialysate flow rate; and a calibration value correction step of correcting the calibration value based on the difference calculated in the difference calculation step.

[0150] According to the above method for adjusting the dialysate flow rate, the current dialysate flow rate can be quickly adjusted to the desired flow rate.

[0151] <2> The method for adjusting the dialysate flow rate according to <1>, wherein the pump control value determination step, the pump operation step, the difference calculation step, and the calibration value correction step are repeated until the difference falls within a predetermined tolerance range.

[0152] According to the above method for adjusting the dialysate flow rate, the current dialysate flow rate can be brought closer to the desired dialysate flow rate.

[0153] <3> The method for adjusting the dialysate flow rate according to <1> or <2>, wherein the difference calculation step and the calibration value correction step are performed when the circulation pump is operated with a new pump control value.

[0154] According to the above method for adjusting the dialysate flow rate, when the desired dialysate flow rate is changed, the current dialysate flow rate can be quickly brought closer to the desired flow rate.

[0155] <4> A method for adjusting the dialysate flow rate according to any one of <1> to <3>, wherein the difference calculation step is performed at predetermined intervals, and the calibration value correction step is performed when the difference calculated in the difference calculation step exceeds a predetermined value.

[0156] According to the above method for adjusting the dialysate flow rate, it becomes possible to adjust the dialysate flow rate as needed, without requiring human monitoring of the dialysate flow rate.

[0157] <5> A personal hemodialysis apparatus 1 comprising a dialysate circuit 30 and a circulation pump 92 provided in the dialysate circuit 30, wherein the output of the circulation pump 92 changes according to a set pump control value, the pump control value is determined based on a calibration value that shows the correlation between a desired dialysate flow rate and the pump control value, and the personal hemodialysis apparatus 1 comprises a flow rate calculation unit 509 that calculates the dialysate flow rate of the dialysate circuit 30, and a correction value calculation unit 507 that corrects the calibration value based on the difference between the dialysate flow rate calculated by the flow rate calculation unit 509 and a desired dialysate flow rate corresponding to a set pump control value.

[0158] According to the hemodialysis machine described above, the current dialysate flow rate can be quickly adjusted to the desired flow rate.

[0159] <6> The correction value calculation unit 507 includes a correction value adjustment unit 511, and the correction value adjustment unit 511, with respect to the continuously calculated dialysate flow rate, when the relationship between the calculated dialysate flow rate when the circulation pump 92 is operated with a pump control value determined based on the calibration value before correction and the desired dialysate flow rate, and when the relationship between the calculated dialysate flow rate when the circulation pump 92 is operated with a pump control value determined based on the calibration value after correction and the desired dialysate flow rate are reversed, the personal hemodialysis apparatus 1 according to <5>, wherein in the next correction of the calibration value, the ratio of the correction amount to the difference between the calculated dialysate flow rate and the desired dialysate flow rate is made smaller than the previous correction of the calibration value.

[0160] According to the hemodialysis machine described above, the current dialysate flow rate can be adjusted to the desired flow rate more reliably and quickly.

[0161] <7> The personal hemodialysis apparatus 1 according to <5> or <6>, wherein the correction value calculation unit 507 includes a dialysate flow rate range out of range determination unit 513, the dialysate flow rate range out of range determination unit 513 determines whether the difference between the current dialysate flow rate and the desired dialysate flow rate exceeds a predetermined range, and the correction value calculation unit 507 corrects the calibration value when the dialysate flow rate range out of range determination unit 513 determines that it exceeds a predetermined value.

[0162] The hemodialysis machine described above allows for adjustment of the dialysate flow rate as needed, without requiring human monitoring of the dialysate flow rate.

[0163] 1. Personal hemodialysis machine 10. Dialyzer 11. Container body 20. Blood circuit 21. Arterial line 22. Venous line 23. Medication line 24. Overflow line 30. Dialysis fluid circuit 31. Dialysis fluid chamber 31A. First dialysis fluid chamber 31B. Second dialysis fluid chamber 32. Concentrate supply line 33. Dialysis fluid inlet line 34. Dialysis fluid outlet line 35. First drain line 36. Second drain line 37. Ultrafiltration / reverse filtration pump 38. Replacement fluid line 39. Replacement fluid pump 40. Heater 50. Control unit 70. Operation unit 80. Display unit 90. Circulation pump line 92. Circulation pump 100. Console 111. Blood inlet 112. Blood outlet 112d. Venous clamp 113. Dialysis fluid inlet 114. Dialysis fluid outlet 212. Blood pump 222 Venous side chamber 231 Drug pump 241 Overflow clamp 311 Container 312 Diaphragm

Claims

1. A method for adjusting the dialysate flow rate in a hemodialysis apparatus comprising a dialysate circuit and a circulating pump provided in the dialysate circuit, comprising: a pump control value determination step of determining a pump control value corresponding to the desired dialysate flow rate based on a calibration value showing the correlation between a desired dialysate flow rate and the pump control value of the circulating pump; a pump operation step of operating the circulating pump with the pump control value determined in the pump control value determination step; a difference calculation step of calculating the difference between the current dialysate flow rate and the desired dialysate flow rate; and a calibration value correction step of correcting the calibration value based on the difference calculated in the difference calculation step.

2. The method for adjusting the dialysate flow rate according to claim 1, wherein the pump control value determination step, the pump operation step, the difference calculation step, and the calibration value correction step are repeated until the difference falls within a predetermined tolerance range.

3. The method for adjusting the dialysate flow rate according to claim 1 or 2, wherein the difference calculation step and the calibration value correction step are performed when the circulation pump is operated with a new pump control value.

4. A method for adjusting the flow rate of dialysate according to any one of claims 1 to 3, wherein the difference calculation step is performed at predetermined intervals, and the calibration value correction step is performed when the difference calculated in the difference calculation step exceeds a predetermined value.

5. A hemodialysis apparatus comprising a dialysate circuit and a circulating pump provided in the dialysate circuit, wherein the output of the circulating pump changes according to a set pump control value, the pump control value is determined based on a calibration value that shows the correlation between a desired dialysate flow rate and the pump control value, and the apparatus comprises a flow rate calculation unit that calculates the dialysate flow rate of the dialysate circuit, and a correction value calculation unit that corrects the calibration value based on the difference between the dialysate flow rate calculated by the flow rate calculation unit and a desired dialysate flow rate corresponding to a set pump control value.

6. The correction value calculation unit comprises a correction value adjustment unit, wherein, with respect to the continuously calculated dialysate flow rate, when the relationship between the calculated dialysate flow rate when the circulation pump is operated with a pump control value determined based on the calibration value before correction and the desired dialysate flow rate, and the relationship between the calculated dialysate flow rate when the circulation pump is operated with a pump control value determined based on the calibration value after correction and the desired dialysate flow rate are reversed, the correction value adjustment unit makes the ratio of the correction amount to the difference between the calculated dialysate flow rate and the desired dialysate flow rate smaller than the previous correction of the calibration value in the next correction of the calibration value, as described in claim 5.

7. The hemodialysis apparatus according to claim 5 or 6, wherein the correction value calculation unit includes a dialysate flow rate range out-of-range determination unit, which determines whether the difference between the current dialysate flow rate and the desired dialysate flow rate exceeds a predetermined range, and the correction value calculation unit corrects the calibration value when the dialysate flow rate range out-of-range determination unit determines that it exceeds a predetermined value.

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