Method for estimating the degree of clogging in a blood purification device, and blood purification device

Abstract

To provide a method for estimating the degree of clogging in a blood purifier during dialysis, and a blood purifier capable of estimating the degree of clogging in a blood purifier during dialysis. [Solution] The method for estimating the degree of clogging in a blood purifier, in hemodialysis treatment using a blood purifier, comprises: a blood marker application step of applying a predetermined amount of blood marker to the circulating blood; a blood marker detection step of detecting the blood marker from the blood that has passed through the blood purifier; a blood marker detection time acquisition step of obtaining the blood marker detection time, which is the time from the time the blood marker is applied to the time the blood marker is detected; and a clogging degree estimation step of estimating the degree of clogging of the dialyzer contained in the blood purifier from the blood marker detection time.

Description

[Technical Field]

[0001] This invention relates to a method for estimating the degree of clogging in a blood purifier, and to a blood purifier. [Background technology]

[0002] In hemodialysis therapy, a method is known in which a blood purifier is connected between the arterial and venous blood circuits, and the blood is purified while being circulated extracorporeally through the blood purifier. Patent Document 1 describes an example of this method. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2019-187888 [Overview of the project] [Problems that the invention aims to solve]

[0004] During dialysis, diffusion and filtration occur through a blood purifier. Clogging of the blood purifier membrane during dialysis affects treatment efficiency and leads to increased dialysate pressure and venous pressure during filtration and backfiltration. Therefore, understanding membrane clogging during dialysis is crucial for managing the procedure. However, to date, no method has been proposed for monitoring membrane clogging over time.

[0005] Therefore, the object of the present invention is to provide a method for estimating the degree of clogging of a blood purifier during dialysis, and a blood purifier capable of estimating the degree of clogging of a blood purifier during dialysis. [Means for solving the problem]

[0006] The method for estimating the degree of clogging of the blood purifier of the present invention includes a blood marker adding step of adding a predetermined amount of blood marker to the circulating blood in hemodialysis treatment using the blood purifier, a blood marker detecting step of detecting the blood marker from the blood that has passed through the blood purifier, a blood marker detection time acquisition step of acquiring a blood marker detection time, which is the time from the point when the blood marker is added to the point when the blood marker is detected, and a clogging degree estimation step of estimating the degree of clogging of the blood purifier included in the blood purifier from the blood marker detection time.

[0007] In addition, the blood purification device of the present invention includes a blood purifier, an arterial line for sending blood to the blood purifier, a venous line for returning the blood purified by the blood purifier to the patient, a blood marker adding means for adding a blood marker to the blood in the blood purifier or the arterial line, an arterial side measuring means provided on the arterial line for measuring the state of the blood flowing through the arterial line, and a control unit for controlling the blood marker adding means and the arterial side measuring means. The control unit estimates the degree of clogging of the blood purifier based on the blood marker detection time from the point when the blood marker is added to the blood by the blood marker adding means to the point when the change in the state of the blood caused by the addition is detected by the arterial side measuring means.

Advantages of the Invention

[0008] According to the present invention, it is possible to provide a method for estimating the degree of clogging of a blood purifier during dialysis and a blood purification device capable of estimating the degree of clogging of a blood purifier during dialysis.

Brief Description of the Drawings

[0009] [Figure 1] It is a diagram showing a schematic configuration of a blood purification device according to an embodiment of the present invention. [Figure 2] It is a block diagram of a blood purification device. [Figure 3A] It is a flowchart showing an outline of creating an analysis model of the recirculation rate. [Figure 3B] It is a flowchart showing the schematic configuration of the method for estimating the recirculation rate. [Figure 4] It is a diagram showing the schematic configuration of the recirculation rate measurement model. [Figure 5] It is a diagram showing the change over time of blood concentration. [Figure 6] It is a schematic diagram showing a part of the blood purification device. [Figure 7] It is a diagram showing a part of the model data. (a) shows the relationship between the low area and the recirculation rate, (b) shows the relationship between the low area and the hematocrit value, (c) shows the relationship between the low area SA and the blood flow rate, and (d) shows the relationship between the low area SA and the UFR / membrane area. [Figure 8] It is a diagram showing an example of a regression equation obtained by multivariate analysis. [Figure 9] It is a schematic diagram of the blood purification device for explaining the acquisition of treatment data. [Figure 10] It is a flowchart showing the flow of acquisition of treatment data. [Figure 11] It is a diagram showing the control of the pump in the process for acquiring treatment data. [Figure 12] It is a diagram showing the correlation between the actual recirculation rate and the estimated recirculation rate. [Figure 13] It is a diagram showing the relationship between the dialyzer ultrafiltration rate and the blood marker detection time. [Figure 14] It is a flowchart showing the outline of the method for estimating the degree of clogging.

Mode for Carrying Out the Invention

[0010] The following describes preferred embodiments for implementing the blood purification device of the present invention with reference to the drawings. The blood purification device of the present invention purifies the blood of patients with renal failure and drug poisoning. Furthermore, in the blood purification device of the first embodiment of the present invention, it is possible to estimate the recirculation rate. Furthermore, in the blood purification device of the second embodiment of the present invention, it is possible to estimate the degree of clogging of the blood purifier. Clogging of the blood purifier refers to clogging of components such as dialysis membranes provided in the blood purifier, such as dialyzers.

[0011] (First Embodiment) The first embodiment will be described with reference to Figure 1. Figure 1 is a diagram showing the schematic configuration of a blood purification device 100 according to the first embodiment of the present invention.

[0012] (Blood purification device 100) As shown in Figure 1, the blood purification device 100 comprises a blood circuit 110, a blood purifier 120, an arterial side measuring means 111M, a venous side measuring means 112M, a dialysate circuit 130, and a control unit 140. Part of the dialysate circuit 130 and the control unit 140 are located within the console 102. The console 102 also includes a water removal and reverse filtration pump 1333 and a fluid replacement pump 150, which are used when adding blood markers to the blood.

[0013] (Blood circuit 110) The blood circuit 110 includes an arterial line 111, a venous line 112, a drug line 113, and a drainage line 114. The arterial line 111, the venous line 112, the drug line 113, and the drainage line 114 are all mainly composed of flexible, soft tubes through which liquid can flow.

[0014] One end of the arterial line 111 is connected to the blood inlet 122a of the blood purifier 120, which will be described later. The arterial line 111 is equipped with an arterial connection part 111a, an arterial bubble detector 111b, and a blood pump 111c.

[0015] The arterial connection 111a is located at the other end of the arterial line 111. The needle that will be used to puncture the patient's blood vessel is connected to the arterial connection 111a. The arterial bubble detector 111b detects the presence or absence of bubbles in the tube. The blood pump 111c is located downstream of the arterial bubble detector 111b in the arterial line 111. The blood pump 111c pumps out blood, priming fluid, and other liquids from inside the arterial line 111 by squeezing the tube that makes up the arterial line 111 with rollers.

[0016] One end of the venous line 112 is connected to the blood outlet 122b of the blood purifier 120, which will be described later. The venous line 112 is equipped with a venous connection part 112a, a venous bubble detector 112b, a drip chamber 112c, and a venous clamp 112d.

[0017] The venous connection port 112a is located on the other end of the venous line 112. The needle that will be used to puncture the patient's blood vessel is connected to the venous connection port 112a. The venous bubble detector 112b detects the presence or absence of bubbles in the tube. The drip chamber 112c is located upstream of the venous bubble detector 112b. The drip chamber 112c stores a certain amount of blood or air to remove bubbles or coagulated blood that have entered the venous line 112, and to measure venous pressure. The venous clamp 112d is located downstream of the venous bubble detector 112b. The venous clamp 112d is controlled according to the bubble detection result by the venous bubble detector 112b and opens and closes the flow path of the venous line 112.

[0018] The drug line 113 supplies the necessary drugs to the arterial line 111 during hemodialysis. One end of the drug line 113 is connected to a drug solution pump 113a that delivers the drugs. The other end of the drug line 113 is connected to the arterial line 111. The drug line 113 is also provided with a clamping mechanism (not shown). The flow path is closed by the clamping mechanism except when injecting drugs. In the first embodiment, the other end of the drug line 113 is connected downstream of the blood pump 111c in the arterial line 111.

[0019] The drain line 114 is connected to the drip chamber 112c. A drain line clamp 114a is positioned on the drain line 114. The process of cleaning and purifying the blood circuit 110 and the blood purifier 120 is called the priming process. The drain line 114 is a line for draining the priming fluid during the priming process.

[0020] (Blood purifier 120) The blood purifier 120 comprises a cylindrical container body 121 and a dialysis membrane (not shown) housed inside the container body 121. The dialysis membrane can be, for example, a dialyzer. The inside of the container body 121 is divided by the dialysis membrane into a blood-side flow path and a dialysate-side flow path, neither of which are shown.

[0021] The container body 121 has a blood inlet 122a and a blood outlet 122b. The blood inlet 122a and blood outlet 122b are in communication with the blood circuit 110. The container body 121 also has a dialysate inlet 123a and a dialysate outlet 123b. The dialysate inlet 123a and dialysate outlet 123b are in communication with the dialysate circuit 130.

[0022] (Arterial side measurement means 111M) The arterial side measuring means 111M is a sensor for measuring the condition of the blood taken from the patient. The arterial side measuring means 111M is provided on the arterial side line 111. In the first embodiment, the arterial side measuring means 111M is located on the arterial side line 111 near the blood inlet 122a of the blood purifier 120.

[0023] (Venous side measurement means 112M) The venous measuring means 112M is a sensor for measuring the state of the blood being returned to the patient. The venous measuring means 112M is provided in the venous line 112. In the first embodiment, the venous measuring means 112M is positioned between the blood purifier 120 and the drip chamber 112c in the venous line 112. The venous measuring means 112M can also be positioned downstream of the drip chamber 112c. The venous measuring means 112M is not essential when measuring blood recirculation. However, by measuring and comparing changes in the state of the blood in both the arterial line 111 and the venous line 112, the accuracy of measuring blood recirculation can be improved compared to measuring blood recirculation based only on changes in the state of the blood in the arterial line 111.

[0024] The blood conditions measured by the arterial measuring means 111M and the venous measuring means 112M specifically include hematocrit, hemoglobin, and electrical resistivity, which change depending on the blood concentration. In the first embodiment, the hematocrit value is measured as an indicator of the blood condition.

[0025] Furthermore, the arterial side measuring means 111M and the venous side measuring means 112M can continuously measure the state of the blood. As a result, the arterial side measuring means 111M and the venous side measuring means 112M can acquire time-series data on changes in the state of the blood.

[0026] Furthermore, the arterial measuring means 111M and the venous measuring means 112M can acquire data on blood flow rate in addition to the blood condition. It should be noted that blood flow rate can also be measured by means other than the arterial measuring means 111M and the venous measuring means 112M. Alternatively, blood flow rate can be measured by the measuring means, and the blood pump's set speed can be used as data in addition to the acquired data.

[0027] According to the blood circuit 110 and blood purifier 120 described above, blood taken from the artery of the dialysis patient is introduced into the blood flow path of the blood purifier 120 via the arterial line 111 by the blood pump 111c. The blood introduced into the blood purifier 120 is purified by the dialysate flowing through the dialysate circuit 130, which will be described later, via the dialysis membrane. The blood purified in the blood purifier 120 is returned to the patient's vein via the venous line 112.

[0028] (Dialysate circuit 130) In the first embodiment, the dialysate circuit 130 is configured as a so-called closed-volume controlled dialysate circuit 130. This dialysate circuit 130 includes a dialysate supply line 131a, a dialysate drain line 131b, a dialysate introduction line 132a, a dialysate outlet line 132b, and a dialysate delivery unit 133.

[0029] The dialysate delivery unit 133 comprises a dialysate chamber 1331, a bypass line 1332, and a water removal and reverse filtration pump 1333. The dialysate chamber 1331 is a rigid container capable of holding a certain volume of dialysate. A certain volume means, for example, 300 mL or more and 500 mL or less. The inside of this container is divided into a delivery storage section 1331a and a drain storage section 1331b by a flexible diaphragm. The diaphragm is also called a diaphragm. The bypass line 1332 connects the dialysate outlet line 132b and the dialysate drain line 131b.

[0030] The ultrafiltration and reverse filtration pump 1333 is located in the bypass line 1332. The ultrafiltration and reverse filtration pump 1333 consists of a pump that drives the dialysate inside the bypass line 1332 to be delivered in the ultrafiltration direction and the reverse filtration direction. The ultrafiltration direction is the direction in which the dialysate flows toward the dialysate drain line 131b. The reverse filtration direction is the direction in which the dialysate flows toward the dialysate outlet line 132b.

[0031] The proximal end of the dialysate supply line 131a is connected to a dialysate supply device (not shown). On the other hand, the tip end of the dialysate supply line 131a is connected to the dialysate chamber 1331. The dialysate supply line 131a supplies dialysate to the fluid supply and containment section 1331a of the dialysate chamber 1331.

[0032] The dialysate introduction line 132a connects the dialysate chamber 1331 to the dialysate inlet 123a of the blood purifier 120. As a result, the dialysate introduction line 132a introduces the dialysate contained in the fluid delivery section 1331a of the dialysate chamber 1331 into the dialysate side flow path of the blood purifier 120.

[0033] The dialysate outlet line 132b connects the dialysate outlet 123b of the blood purifier 120 to the dialysate chamber 1331. As a result, the dialysate outlet line 132b leads the dialysate discharged from the dialysate side flow path of the blood purifier 120 to the drain collection section 1331b of the dialysate chamber 1331.

[0034] The dialysate drain line 131b is connected at its proximal end to the dialysate chamber 1331. As a result, the dialysate drain line 131b discharges the dialysate contained in the drain collection section 1331b.

[0035] According to the dialysate circuit 130 described above, the inside of the rigid container constituting the dialysate chamber 1331 is partitioned by a flexible diaphragm. This makes it possible to make the amount of dialysate discharged from the dialysate chamber 1331 equal to the amount of drainage collected in the dialysate chamber 1331 in the dialysate circuit 130. The amount of dialysate discharged from the dialysate chamber 1331 is equal to the amount of dialysate supplied to the fluid delivery and storage unit 1331a. Also, the amount of drainage collected in the dialysate chamber 1331 is equal to the amount of drainage collected in the drainage storage unit 1331b.

[0036] This allows the flow rate of dialysate introduced into the blood purifier 120 and the amount of dialysate discharged from the blood purifier 120 to be equal when the water removal and reverse filtration pump 1333 is stopped. The dialysate discharged from the blood purifier 120 is also called drainage fluid.

[0037] Furthermore, when the ultrafiltration and reverse filtration pump 1333 is driven to pump fluid in the ultrafiltration direction, a predetermined amount of ultrafiltration is removed from the blood at a predetermined rate in the blood purifier 120. Also, when the ultrafiltration and reverse filtration pump 1333 is driven to pump fluid in the reverse filtration direction, a predetermined amount of dialysate is injected into the blood circuit 110 in the blood purifier 120. The injection of a predetermined amount of dialysate into the blood circuit 110 is also called reverse filtration.

[0038] (Control unit 140) The control unit 140 is composed of an information processing device such as a computer. Specifically, as shown in Figure 2, the control unit 140 controls the operation of the blood purification device 100 by executing a control program. Specifically, the control unit 140 controls the operation of various pumps and clamps, including the replacement fluid pump 150P, which are located in the blood circuit 110 and the dialysate circuit 130, to execute various processes performed by the blood purification device 100. These various processes include, for example, the priming process, the blood withdrawal process, the dialysis process, the replacement fluid process, and the blood return process.

[0039] Of the various processes described above, the dialysis process and the fluid replacement process will be explained below. (dialysis process) In the dialysis process, excess fluid from the patient is removed and waste products are eliminated. During the dialysis process, the patient's blood, introduced from the arterial connection 111a, is purified by the blood purifier 120 through the arterial line 111. The purified blood is returned to the patient through the venous line 112 and the venous connection 112a.

[0040] During the dialysis process, the arterial connection 111a and the venous connection 112a are connected to needles that will be inserted into the patient's blood vessels. The drainage line clamp 114a is closed, and the venous clamp 112d is open.

[0041] (fluid replacement process) The fluid replacement procedure is a process aimed at increasing the patient's circulating blood volume. It can be performed as needed if symptoms such as a drop in blood pressure or muscle cramps occur during the dialysis process. Furthermore, the fluid replacement procedure can be planned and performed multiple times at regular intervals during the dialysis process to prevent a drop in blood pressure and improve peripheral circulation.

[0042] As a means of fluid replacement, a blood purifier 120, a dialysate introduction line 132a, a dialysate discharge line 132b, and a dialysate delivery unit 133 are used, and the reverse filtration dialysate injected into the venous line 112 via the blood purifier 120 can be used as replacement fluid.

[0043] The method of performing the fluid replacement process is not limited to injecting fluid into the venous line 112 via the blood purifier 120. As another method of performing the fluid replacement process, for example, depending on the configuration of the blood circuit 110, fluid can also be injected directly into the arterial line 111 or the venous line 112.

[0044] In the fluid replacement process, similar to the dialysis process, the arterial connection 111a and the venous connection 112a are connected to needles that will be inserted into the patient's blood vessels. The drainage line clamp 114a is closed, and the venous clamp 112d is open.

[0045] As explained above, the amount of fluid injected during the fluid replacement process increases the patient's circulating blood volume. Therefore, in order to remove excess fluid to the patient's target weight during the dialysis process, the dialysis time needs to be extended if the fluid removal rate is constant. Alternatively, by increasing the fluid removal rate to remove the amount increased by the fluid replacement, it is possible to remove excess fluid to the target weight without extending the dialysis time.

[0046] (Estimation of recirculation rate) The estimation of the recirculation rate will now be explained. In the blood purification device 100 of this embodiment, the recirculation rate can be determined by estimation without measuring the state of the blood before recirculation using the venous side measuring means 112M. The estimation of the recirculation rate includes acquiring model data using a recirculation rate measurement model, multivariate analysis of the acquired model data, derivation of a regression equation from the multivariate analysis, acquisition of treatment data during hemodialysis treatment, and estimation of the recirculation rate by substituting the treatment data into the regression equation. The estimation process is shown below.

[0047] Figure 3A is a flowchart illustrating the outline of creating an analysis model for the recirculation rate. (S1) S1 is the starting step. At S1, the flow for estimating the recirculation rate begins. Here, S1 represents step 1. The same applies to the other steps. (S2) S2 is the model data acquisition step. In S2, data is acquired for use in the multivariate analysis in S3. Data acquisition is performed using a recirculation rate measurement model. The data acquired in S2 is used as model data. (S3) S3 is the analysis step. In S3, the model data obtained in S2 is subjected to multivariate analysis. This multivariate analysis derives a regression equation with the recirculation rate as the dependent variable. (S4) S4 is the final step. In S4, the flow for creating the recirculation rate analysis model ends.

[0048] Figure 3B is a flowchart showing the schematic configuration of the method for estimating the recirculation rate in this embodiment. (S11) S11 is the start step. In S11, the flow for estimating the recirculation rate begins. (S12) S12 is the treatment data acquisition step. In S12, data is measured during the actual treatment to be input into the regression equation derived in S3. Data can be measured from blood flowing through the arterial or venous line. The data acquired in S12 is considered the treatment data. (S13) S13 is the recirculation rate estimation step. In S13, the treatment data obtained in S12 is input to the regression equation derived in S3. This gives the estimated recirculation rate. (S14) S14 is the termination step. In S14, the flow for estimating the recirculation rate ends.

[0049] In the above explanation, multivariate analysis may also be performed using machine learning to create a model. In that case, the regression equation can be used in the transformation model, and the input of treatment data to the regression equation can be used in the transformation model.

[0050] Step S2 for acquiring model data will be explained. (Recirculation rate measurement model) The recirculation rate measurement model 200 will be described based on Figure 4. Figure 4 is a diagram showing the schematic configuration of the recirculation rate measurement model 200. In the recirculation rate measurement model 200, the biological parts connected to the arterial connection 111a and venous connection 112a in the blood purification device 100 shown in Figure 1 are replaced with blood bottles 202 and drainage bottles 204, etc. The recirculation rate measurement model 200 will be described below, focusing on the differences from the blood purification device 100 shown in Figure 1.

[0051] The recirculation rate measurement model 200 is equipped with a blood bottle 202 and a drainage bottle 204. Blood is supplied from the blood bottle 202 through the blood withdrawal line 220 and arterial connection 111a to the blood purifier 120 and other devices. This blood flow is indicated by arrow AR1.

[0052] The blood purified by the blood purifier 120 returns to the blood bottle 202 via the venous connection port 112a and the return line 222. This blood flow is indicated by arrow AR2.

[0053] A first three-way stopcock 231 is located in the blood withdrawal line 220. A second three-way stopcock 232 and a third three-way stopcock 233 are located in the return line 222. The first three-way stopcock 231 and the second three-way stopcock 232 are connected by a recirculation line 226. A metering pump 240 is provided in the recirculation line 226.

[0054] The third three-way stopcock 233 is connected to the drain bottle 204 via the drain line 224.

[0055] In the recirculation rate measurement model 200, the flow direction of the three three-way stopcocks mentioned above can be switched between a non-recirculating state and a recirculating state.

[0056] (Not recirculating) The blood flow in the non-recirculating state is indicated by arrow L10. In the non-recirculating state, blood flows from the blood bottle 202 through the blood withdrawal line 220 towards the arterial connection 111a. The opening direction of the first three-way stopcock 231, located between the blood bottle 202 and the arterial connection 111a, is such that blood does not flow through the recirculation line 226 but flows through the blood withdrawal line 220. Therefore, the entire volume of blood flows towards the arterial connection 111a.

[0057] With regard to the blood returning from the venous connection 112a to the blood bottle 202, the opening directions of the second three-way stopcock 232 and the third three-way stopcock 233 are as follows: The opening direction of the second three-way stopcock 232 is such that the blood does not flow through the recirculation line 226, and the entire volume of blood flows through the return line 222. The opening direction of the third three-way stopcock 233 is such that the blood does not flow through the blood bottle 202, and the entire volume of blood flows through the drainage line 224. Therefore, the entire volume of blood from the venous connection 112a flows through the drainage line 224 and into the drainage bottle 204.

[0058] (In a state of recirculation) The blood flow in the recirculation state is indicated by arrow L11. In the recirculation state, blood flows from the blood bottle 202 through the blood withdrawal line 220 towards the arterial connection 111a. The first three-way stopcock 231, located along this path, is opened in three directions, including the recirculation line 226, so that blood flows through the blood withdrawal line 220. The blood flow up to this point is the same as in the non-recirculation state. Note that when the metering pump 240 is stopped, the flow path of the recirculation line 226 is blocked, so no blood flows from the blood withdrawal line 220 to the return line 222.

[0059] In the recirculation state, at the first three-way stopcock 231, the blood that has flowed through the recirculation line 226 merges with the blood that has flowed through the blood withdrawal line 220. This blood that has flowed through the recirculation line 226 corresponds to the recirculated blood.

[0060] The blood flowing from the venous connection 112a through the return line 222 is partially recirculated, and the remainder is discarded into the drainage bottle. With regard to the flow of blood returning from the venous connection 112a towards the blood bottle 202, the opening directions of the second three-way stopcock 232 and the third three-way stopcock 233 are as follows: The opening direction of the second three-way stopcock 232 is such that a portion of the blood flows through the recirculation line 226, and the remaining blood flows through the return line 222.

[0061] The direction in which the third three-way stopcock 233 is opened is such that the entire volume of blood flows through the drainage line 224.

[0062] By directing the opening of the second three-way stopcock 232 and the third three-way stopcock 233 as described above, a state of blood recirculation can be created. Furthermore, by adjusting the opening direction of the second three-way stopcock 232 and the flow rate ratio between the blood flow rate from the blood pump 111c and the metering pump 240, various recirculation rates can be achieved.

[0063] (Blood markers) This section explains blood markers. Examples of blood markers that can be added to blood circulating extracorporeally include reverse filtration, online fluid replacement (pre-dilution or post-dilution), and filtration.

[0064] Reverse filtration fluid replacement refers to the injection of replacement fluid in the dialyzer contained in the blood purifier 120. Pre-dilution refers to the injection of replacement fluid into the blood upstream of the blood purifier 120. Post-dilution refers to the injection of replacement fluid into the blood downstream of the blood purifier 120. Filtration refers to the removal of water in the filtration direction in the dialyzer contained in the blood purifier 120.

[0065] The addition of blood markers involves temporarily altering the blood concentration by injecting or filtering replacement fluid into the blood. The portion of the blood whose concentration has temporarily changed becomes the marker. Note that a different fluid from the dialysate may be used as replacement fluid, or the dialysate may be used as replacement fluid.

[0066] (Assignment of blood markers) This section explains the locations on the line where blood markers are added to the blood. Figure 4 shows the points where blood markers are added, labeled P1 to P4. The points where blood markers are added are the points where replacement fluids are injected into the blood or where the blood is filtered.

[0067] Point P1 indicates the application point of the first blood marker. The first application point P1 is the application point of the blood marker when the blood marker is obtained through reverse filtration. The first application point P1 is located, for example, in the dialysate introduction line 132a.

[0068] Point P2 indicates the application point for the second blood marker. The second application point P2 is the application point for the blood marker when the blood marker is pre-diluted. The second application point P2 is located, for example, on the arterial line 111.

[0069] Point P3 indicates the application point for the third blood marker. The third application point P3 is the application point for the blood marker when the blood marker is post-diluted. The third application point P3 is located, for example, on the venous line 112.

[0070] Point P4 indicates the point of application for the fourth blood marker. Point P4 is the point of application for the blood marker when the blood marker is filtration. Point P4 is located, for example, in the dialysate outlet line 132b.

[0071] (Measurement of blood concentration) By adding blood markers to the blood through fluid replacement, the blood concentration decreases. Conversely, by adding blood markers to the blood through filtration, the blood concentration increases. This change in blood concentration is detected by the measurement unit. The measurement unit is the part that measures blood concentration over time. The measurement unit is located in different positions depending on the type of blood marker.

[0072] The measurement unit in the recirculation rate measurement model 200 is positioned upstream of the blood marker application point and downstream of the recirculation line 226 in order to measure the blood before it passes through the blood purifier. This is because the blood that has flowed through the recirculation line 226 corresponds to the recirculated blood.

[0073] If the blood marker is obtained by backfiltration, post-dilution, or filtration, the measuring unit can be an arterial measuring means 111M. This is because the arterial measuring means 111M is positioned upstream of the first application point P1 and the third application point P3, and downstream of the recirculation line 226.

[0074] If the blood marker is pre-diluted, the measurement unit can be the second arterial-side measurement means 111M'. The second arterial-side measurement means 111M' is located downstream of the first three-way stopcock 231 in the return line 222. If the blood marker is pre-diluted, the measurement unit cannot be the arterial-side measurement means 111M. This is because the arterial-side measurement means 111M is located downstream of the second application point P2 and downstream of the recirculation line 226.

[0075] (Detection of blood markers) Based on Figures 5 and 6, the detection of blood markers by fluid replacement will be explained. Figure 5 shows the change in blood concentration over time as measured by the measurement unit. Figure 6 is a schematic diagram showing a part of the blood purification device 1. The detection of blood markers by filtration is similar, except that the change in blood concentration is the reverse of that with fluid replacement.

[0076] In the graph shown in Figure 5, the horizontal axis represents time, and the vertical axis represents hematocrit. Here, hematocrit is used as a value indicating blood concentration. Hematocrit is a numerical value that indicates the percentage of the volume of blood occupied by red blood cells. As shown in Figure 6, when blood with a blood marker is added is recirculated in the body, a change in blood concentration is detected at the measurement unit. This is because the change in blood concentration due to the addition of the blood marker is detected at the measurement unit without being diminished in the body.

[0077] Figure 5 H A This shows the average hematocrit value. As shown in Figure 5, for recirculated blood, time T S Blood markers administered via fluid replacement showed that at time T1, the hematocrit value began to decrease rapidly, and the average hematocrit value was HA It becomes as follows. Time T B At this time, the hematocrit value reaches the lowest value, and the hematocrit value begins to increase. Time T B The hematocrit value at time T, and the average value H A The difference between and is the drop width H B It is.

[0078] The hematocrit value starts to decrease again at time T E At. The average value H of the hematocrit value from time T1 to time T E Let the change amount from be S A Let it be. This change amount S A In FIGS. 5 and 6, is shown as the change area S A This change area S A Corresponds to the change amount of blood concentration. A

[0079] Note that time T1 is the timing when the detector starts to detect the blood marker applied by recirculation. This T1 is obtained from the filling amount in the circuit and the speed of the blood pump. For example, when the blood filling amount in the circuit is 200 mL and the blood pump speed is 250 mL / min, 200 / 250 = 0.8 (≈50 seconds = (T1 - T s )) When the detector starts to detect from time T1, the detection accuracy is improved, and false detection can be suppressed.

[0080] (Model data) ​In this embodiment, the recirculation rate measurement model 200 is used to obtain model data for determining the regression equation, which will be explained later. The model data includes data showing the change in blood concentration after recirculation when a predetermined amount of blood marker is added to the extracorporeal circulation blood, data showing the relationship between the change in blood concentration after recirculation and the blood concentration, data showing the relationship between the change in blood concentration after recirculation and the blood flow rate, data showing the relationship between the blood marker detection time (the time from recirculation to the point in time when the blood marker is detected) and the type of dialyzer used in the recirculation rate measurement model, and data showing the relationship between the type of dialyzer and the change in blood concentration after recirculation. The predetermined amount of blood marker is not particularly limited, but for example, it can be the minimum detectable amount.

[0081] Furthermore, the aforementioned measuring unit can be configured to measure items other than blood concentration, such as blood flow rate, in addition to blood concentration. Alternatively, a separate measuring unit can be provided in addition to the aforementioned measuring unit to measure items other than blood concentration.

[0082] Model data can be obtained under conditions such as those listed below. The model parameters and their settings are listed below. Planned fluid replacement volume: 20 mL Fluid replacement rate: 250mL / min

[0083] Also, the area of ​​change S A The following is a list of factors that can change the value and an example of the corresponding test conditions. Recirculation rate: 0% or more and 100% or less Ht (Hematocrit value (bovine bloodline)): 10% to 50% Blood flow (QB:Quantity of Blood flow): 100mL / min or more and 400mL / min or less UFR / membrane area: 6 or more and 52.3 or less UFR: 12mL / mmHg / hr or more and 84mL / mmHg / hr or less Membrane area: 0.8 square meters or more and 2.5 square meters or less

[0084] UFR stands for Ultra Filtration Rate of the dialyzer. Membrane area refers to the hollow fiber membrane area. The recirculation rate can be set to various rates by adjusting the direction of opening of each of the three-way stopcocks or the output of the metering pump 240.

[0085] Figure 7 shows a portion of the model data obtained using the recirculation rate measurement model 200. Figure 7(a) shows the change area S. A This graph shows the relationship between the change area S and the recirculation rate. Figure 7(b) shows the change area S A This graph shows the relationship between and the hematocrit value. Figure 7(c) shows the change area S A This graph shows the relationship between and blood flow rate (QB). Figure 7(d) shows the area of ​​change S A This graph shows the relationship between UFR / membrane area. Note that UFR / membrane area usually varies depending on the type of dialyzer.

[0086] Furthermore, Figures 7(a) to 7(d) show the cases of blood markers in reverse filtration, pre-dilution, and post-dilution. As shown in Figures 7(a), 7(b), and 7(d), the change area S A The relationship between the recirculation rate and the change area S A The relationship between the hematocrit value and the change area S. A The relationship between UFR and film area exhibits a linear correlation.

[0087] The strength of the correlation is shown by the change area S in Figure 7(d). A A correlation has been shown between blood markers and UFR / membrane area, except in cases where the blood markers are post-diluted and do not pass through the blood purifier.

[0088] Furthermore, as shown in Figure 7(c), the area of ​​change S A The relationship between this and blood flow (QB) exhibits an exponential correlation.

[0089] Let's explain analysis step S3. (Multivariate analysis) The model data acquired in step S2 is subjected to multivariate analysis. The model data consists of pairs of correlated values. By analyzing the model data, a regression equation is obtained with the recirculation rate as the dependent variable.

[0090] As an example of multivariate analysis, the area of ​​change S shown in Figure 7(a) is an example of multivariate analysis. A The model data showing the relationship between the recirculation rate and the change area S is shown in Figure 7(b). A The model data showing the relationship between and the hematocrit value, and the change area S shown in Figure 7(d) A We will perform a multivariate analysis using model data that shows the relationship between UFR and membrane area.

[0091] Figure 8 shows an example of a regression equation obtained by multivariate analysis. The analytical method used in multivariate analysis is not particularly limited. For example, multiple regression analysis can be used.

[0092] Area of ​​change S A Model data showing the relationship between and the recirculation rate, and the area of ​​change S A Model data showing the relationship between and hematocrit value, and the area of ​​change S A When performing multivariate analysis using model data showing the relationship between UFR / membrane area and deriving a regression equation with recirculation rate as the dependent variable, the explanatory variables are the change in blood concentration after recirculation, blood concentration, and blood flow rate. Here, the change in blood concentration after recirculation is the change area S. A It is the same content as above.

[0093] (modified version) The types of model data used in multivariate analysis and the explanatory variables in the regression equation are not limited to the examples given above. Any data that correlates with the recirculation rate can be used for multivariate analysis. Furthermore, the explanatory variables can be set to match the data used in the multivariate analysis.

[0094] Let's explain another example. The time from the application of the blood marker to the detection of the blood marker is defined as the blood marker detection time. The blood marker detection time can also be added as an explanatory variable in the regression equation. The blood marker detection time correlates with the type of dialyzer. The type of dialyzer corresponds to the UFR / membrane area shown in Figure 7(d), because the UFR / membrane area is determined by the type of dialyzer. And the UFR / membrane area is the change area S A It is correlated with the change area S. A This correlates with the recirculation rate. Therefore, when deriving a regression equation with the recirculation rate as the dependent variable, data on blood marker detection time can be included in the data used for multivariate analysis. Furthermore, by including data on blood marker detection time in the multivariate analysis, blood marker detection time can be included as an explanatory variable in the regression equation.

[0095] Specifically, additional data will be acquired showing the relationship between blood marker detection time and the type of dialyzer used in the recirculation rate measurement model, and the relationship between the type of dialyzer and the change in blood concentration after recirculation. More precisely, blood marker detection time is the time from the moment a predetermined amount of blood marker is added to the extracorporeal circulation blood until the time when the blood marker is detected after recirculation.

[0096] Next, a multivariate analysis is performed, including the acquired additional data. In this way, a regression equation can be obtained that includes blood marker detection time as an explanatory variable.

[0097] In determining the blood marker detection time, the time point at which the blood marker is detected is time T as shown in Figure 5. B This can be done as follows: In other words, when detecting blood markers, changes in blood concentration are obtained over time. Then, after the blood marker is added, the point in time when the blood concentration changes from decreasing to increasing can be considered the point in time when the blood marker was detected.

[0098] By increasing the types of model data and the number of explanatory variables in the regression equation, it may be possible to estimate a recirculation rate that is closer to the actual recirculation rate using the regression equation.

[0099] Each step from step S1 to step S3 for obtaining the regression equation can be performed, for example, by an analysis device equipped with a recirculation rate measurement model 200. This analysis device may include a model data acquisition unit that acquires model data using the recirculation rate measurement model 200, and an analysis unit that performs multivariate analysis using the model data and derives the regression equation.

[0100] The treatment data acquisition step S12 is explained below. In the treatment data acquisition step S12, various data are acquired during actual hemodialysis treatment. To distinguish it from model data acquired using the recirculation rate measurement model, the data acquired during hemodialysis treatment is called treatment data. Treatment data is acquired in order to estimate the recirculation rate by substituting this data into a regression equation.

[0101] The types of data acquired during treatment correspond to the explanatory variables in the regression equation used to estimate the recirculation rate. For example, if the explanatory variables in the regression equation are the change in blood concentration after recirculation, blood concentration, and blood flow rate, then the change in blood concentration after recirculation, blood concentration, and blood flow rate will be acquired during treatment. Also, if the explanatory variables in the regression equation include blood marker detection time, then blood marker detection time will be acquired during treatment as well.

[0102] The type of blood marker used when acquiring treatment data should be the same as the type of blood marker used when acquiring model data. For example, if reverse filtration was used as the blood marker when acquiring model data, then reverse filtration should also be used as the blood marker when acquiring treatment data. This allows for a more accurate estimation of the recirculation rate.

[0103] (Treatment device) Figure 9 shows a schematic configuration of the blood purification device 100 used to acquire data during treatment. The following explanation will focus on the differences from those described in Figures 1 and 4.

[0104] During actual hemodialysis treatment, the arterial line 111 and the venous line 112 are connected to the body.

[0105] In Figure 9, A indicates the blood marker application point when the blood marker is applied via reverse filtration. When A is the blood marker application point, it corresponds to the case where the blood purification device 100 is under automatic reverse filtration control.

[0106] Arrow B in Figure 9 indicates the flow of replacement fluids when the blood marker is pre-diluted. When replacement fluids flow along arrow B, it corresponds to the case where the blood purification device 100 is under online automatic control for pre-dilution.

[0107] Arrow C in Figure 9 indicates the flow of replacement fluids, etc., when the blood marker is post-diluted. When replacement fluids, etc., flow along arrow C, it corresponds to when the blood purification device 100 is using online automatic control for post-dilution.

[0108] In Figure 9, D indicates the blood marker application point when the blood marker is filtered. When D is the blood marker application point, it corresponds to when the blood purification device 100 is controlled for filtration.

[0109] As shown in Figure 9, the console 102 of the blood purification device 100 used for treatment is equipped with a fluid replacement pump 150 used to add blood markers to the blood. From the fluid replacement pump 150, fluid replacement or dialysate as replacement fluid is supplied to the second application point P2 or the third application point P3 via the fluid replacement line 152.

[0110] Specifically, if the blood marker is pre-diluted, the replacement fluid is supplied to the second administration point P2 via the replacement fluid line 152 along arrow B, under pressure from the replacement fluid pump 150.

[0111] Furthermore, if the blood marker is post-diluted, the replacement fluid is supplied to the third administration point P3 through the replacement fluid line 152 along arrow C, under pressure from the replacement fluid pump 150.

[0112] In Figure 9, the blood purification device 100 has a pressure monitoring line 160 connected to the drip chamber 112c. Figure 9 also includes examples of flow rates for each line.

[0113] (measurement) The measurement of blood concentration and other parameters will now be explained. Measurement can be performed using the measurement unit described above. The measurement unit described above includes, for example, the arterial side measurement means 111M or the second arterial side measurement means 111M'. As the measurement unit, for example, a circulating blood volume monitor (hematocrit measuring device) can be used. Furthermore, in the blood purification device 100 of this embodiment, measurement of blood concentration and other parameters on the venous side is not required. In the blood purification device 100 of this embodiment, the recirculation rate can be estimated by measuring blood concentration and other parameters only on the arterial side.

[0114] An example of acquiring treatment data will be explained in more detail based on Figures 10 and 11. Figure 10 is a flowchart showing the flow of acquiring treatment data. Figure 11 is a diagram showing the control of each pump in each step of acquiring treatment data. The measurement flow during treatment will be explained below based on Figures 10 and 11. K2 in Figure 10 represents step 2. The same applies to the other steps. The step numbers in Figure 10 correspond to the step numbers in Figure 11.

[0115] (Process 1) Step 1 is the step before the measurement flow for acquiring treatment data begins. In Step 1, the ultrafiltration and reverse filtration pump 1333 rotates forward, reverses, or stops as appropriate. In Figure 11, the ultrafiltration and reverse filtration pump 1333 is simply referred to as the ultrafiltration pump. The fluid replacement pump 150 rotates or stops as appropriate. The blood pump 111c is rotating, and dialysis treatment is being performed.

[0116] (Process 2) Step 2 is the step in which the measurement flow begins. In Step 2, the water removal pump 1333, the fluid replacement pump 150, and the blood pump 111c operate in the same manner as in Step 1.

[0117] (Step 3) Step 3 is the circulation step. In step 3, the water removal pump 1333 and the fluid replacement pump 150 are stopped. The blood pump 111c operates in the same manner as in step 1. As a result, blood circulates through the blood circuit 110 without the supply of replacement fluids or other fluids.

[0118] (Step 4) Step 4 is a step to determine if the state is stable. In step 4, it is determined whether or not the state of blood purification is stable. Since step 4 is a step to determine if the state is stable, the water removal pump 1333 and the fluid replacement pump 150 are stopped, just as in step 3.

[0119] If the blood purification state is determined to be stable, proceed to step 5. If the blood purification state is not determined to be stable, proceed to step 8 and the measurement flow ends. Whether or not the blood purification state is stable can be determined, for example, by changes in blood concentration over time.

[0120] (Step 5) Step 5 is the circuit pressure stabilization step. In step 5, in addition to the water removal pump 1333 and the fluid replacement pump 150 that were stopped in step 4, the blood pump 111c is stopped. By stopping the circulation of blood, the internal pressure of the blood circuit 110 is stabilized.

[0121] (Step 6) Step 6 is the blood marker application step. The control of the water removal pump 1333 and the fluid replacement pump 150 differs depending on the type of blood marker to be applied. If the blood marker is reverse filtration, in the automatic reverse filtration control, the water removal pump 1333 rotates in reverse and the fluid replacement pump 150 stops. If the blood marker is filtration, in the water removal control, the water removal pump 1333 rotates in the forward direction and the fluid replacement pump 150 stops.

[0122] If the blood marker is pre-diluted or post-diluted, in the online fluid replacement control, the water removal pump 1333 rotates in reverse and the fluid replacement pump 150 rotates. In the case of pre-dilution, fluid replacement is injected into the arterial line 111 from the second injection point P2. On the other hand, in the case of post-dilution, fluid replacement is injected into the venous line 112 from the third injection point P3.

[0123] Regardless of the type of blood marker being administered, the blood pump 111c will rotate. The rotation speed will be, for example, 30 mL / min.

[0124] (Step 7) Step 7 is the blood marker measurement step. The blood pump 111c rotates under the conditions prior to measurement. This ensures that blood circulation continues as it did during treatment. Meanwhile, the water removal pump 1333 and the fluid replacement pump 150 are stopped. This allows for the measurement of the effects of only the blood markers applied in step 6.

[0125] (Step 8) Step 8 is the final step. The water removal pump 1333, the fluid replacement pump 150, and the blood pump 111c continue in the state of step 7.

[0126] (Step 9) Step 9 is a post-measurement step. The measurement was completed in Step 8. Therefore, the water removal pump 1333, the fluid replacement pump 150, and the blood pump 111c return to the state of Step 1, which is the pre-measurement step.

[0127] The acquisition of treatment data, including the supply of replacement fluids, measurement of various values, and operation of each pump, as described above, can be controlled by the control unit 140 described earlier.

[0128] Let's explain step S5, which estimates the recirculation rate. In S5, the treatment data obtained in S4 is substituted into the regression equation derived in S3. This allows us to obtain the estimated recirculation rate.

[0129] Figure 12 shows an example of the correlation between the recirculation rate estimated in step S13 and the actual recirculation rate. Figure 12 is a diagram showing the correlation between the estimated recirculation rate and the actual recirculation rate. The horizontal axis of the graph in Figure 12 is the actual recirculation rate. The vertical axis of the graph in Figure 12 is the estimated recirculation rate. The actual recirculation rate is the actual recirculation rate. The estimated recirculation rate is the recirculation rate estimated in step S13.

[0130] As shown in Figure 12, there is a correlation between the estimated recirculation rate and the actual recirculation rate. Furthermore, the estimated recirculation rate closely matches the actual recirculation rate. Note that the graph in Figure 12 shows an example where reverse filtration infusion is used as a blood marker. Even when online infusion (pre-dilution or post-dilution) or filtration is used as a blood marker, the estimated recirculation rate closely matches the actual recirculation rate, similar to the reverse filtration infusion example shown in Figure 12.

[0131] The steps of obtaining the estimated recirculation rate in steps S12 and S13 can be performed, for example, by the control of the control unit 140 of the blood purification device 100. When performed by the control unit 140, the control unit 140 may include a treatment data acquisition unit that acquires treatment data using each part arranged in the blood circuit 110, and a recirculation rate estimation unit that estimates the recirculation rate by substituting the treatment data acquired by the treatment data acquisition unit into a regression equation determined by an analysis device.

[0132] According to the method for estimating the recirculation rate of the first embodiment, it is possible to estimate the recirculation rate without being limited by the location of blood marker creation and the placement of blood marker detection means. This is because it eliminates the need to place the measurement means on the venous side, increasing the degree of freedom regarding the location of blood marker creation and blood marker detection means.

[0133] (Second embodiment) A second embodiment will now be described. The second embodiment relates to a method for estimating the degree of clogging of a dialyzer used in a blood purifier 120. The second embodiment will be described below, focusing on the differences from the first embodiment.

[0134] The degree of dialyzer clogging can be estimated based on the blood marker detection time. The blood marker detection time is the time from when a predetermined amount of blood marker is added to extracorporeal circulation blood until the blood marker is detected after passing through the dialyzer.

[0135] In determining the blood marker detection time, the time point at which the blood marker is detected is time T as shown in Figure 5. B This can be done as follows: In detecting blood markers, blood concentrations are obtained over time. Then, after the blood marker is added, the point in time when the concentration changes to an extreme value can be considered the point in time when the blood marker was detected.

[0136] Figure 13 shows UFR and time T. B The relationship is shown in Figure 13. Figure 13 shows the UFR per unit area and time T. B This figure shows the relationship. The horizontal axis of the graph in Figure 13 is UFR / ESA. The vertical axis of the graph in Figure 13 is time T. B UFR stands for Ultra Filtration Rate of the dialyzer. ESA stands for Diameter Surface Area of ​​the dialyzer. Time T B This indicates the blood marker detection time.

[0137] As shown in Figure 13, as UFR increases, T B The value decreases. This indicates that as the water permeability of the dialyzer increases, the blood marker detection time decreases. In other words, as the water permeability of the dialyzer decreases, the blood marker detection time increases. Here, the decrease in the water permeability of the dialyzer is due to clogging of the dialyzer. Therefore, the graph in Figure 13 shows that when the dialyzer becomes clogged, the blood marker detection time increases.

[0138] From the above, it is possible to estimate the degree of dialyzer clogging by measuring the blood marker detection time. Measuring the blood marker detection time makes it possible to estimate the degree of membrane clogging during dialysis treatment, in addition to identifying the type of dialyzer as described in the first embodiment. Furthermore, by measuring the blood marker detection time over time, the degree of clogging can be estimated over time.

[0139] In the second embodiment, the application of blood markers to the blood and the measurement of blood concentration can be carried out by the same means as in the first embodiment. Furthermore, administering fluids multiple times at regular intervals during the dialysis process (intermittent fluid replacement) can also be used as a method for applying blood markers.

[0140] However, in the second embodiment, the application of blood markers is performed by one of the following: injecting replacement fluid into the blood upstream of the blood purifier 120, injecting replacement fluid into the blood purifier 120 in the reverse filtration direction, or performing water removal in the blood purifier 120 in the filtration direction. That is, in the first embodiment, the application of blood markers was selected from reverse filtration replacement fluid, online replacement fluid (pre-dilution or post-dilution), and filtration. In contrast, in the second embodiment, the application of blood markers is one of reverse filtration, pre-dilution, or filtration. In post-dilution, the position where replacement fluid is supplied is downstream of the blood purifier 120. Therefore, post-dilution is unsuitable for detecting clogging in the blood purifier 120. The application of blood markers by reverse filtration, pre-dilution, or filtration can be performed using the same means as described in the first embodiment as the blood marker application means in the second embodiment.

[0141] The general flow of the method for estimating the degree of dialyzer clogging, as described above, can be summarized as follows. Figure 14 is a flowchart showing the flow of the method for estimating the degree of dialyzer clogging.

[0142] (S21) In step S21, this estimated flow begins. (S22) Step S22 is the blood marker addition step. In step S22, a predetermined amount of blood markers is added to the extracorporeal circulation blood during actual hemodialysis treatment using the blood purifier 120. The predetermined amount can be, for example, an amount that does not interfere with the treatment and allows for the detection of the blood markers. This blood marker addition step can be substituted with intravenous fluid replacement (reverse filtration fluid replacement or online automated (pre-dilution)) or filtration during treatment. (S23) Step S23 is a blood marker detection step. In step S23, blood markers are detected from the blood that has passed through the blood purifier 120. (S24) Step S24 is a step to obtain the blood marker detection time. In step S24, the blood marker detection time is obtained, which is the time from the time the blood marker is applied to the time the blood marker is detected. (S25) Step S25 is a step for estimating the degree of clogging. In step S25, the degree of clogging of the dialyzer in the blood purifier 120 is estimated from the blood marker detection time obtained in step S24. (S26) In step S26, this estimated flow ends.

[0143] The method for estimating the degree of clogging, specifically steps S22 to S25 described above, can be performed, for example, by the control of the control unit 140 of the blood purification device 100. When performed by the control unit 140, the control unit 140 controls a blood marker application means for applying blood markers to the blood in the blood purifier 120 or the arterial line 111, an arterial measuring means 111M provided in the arterial line 111 for measuring the state of the blood flowing through the arterial line 111, a venous measuring means 112M provided in the venous line 112 for measuring the state of the blood flowing through the venous line 112, or a second arterial measuring means 111M', and can estimate the degree of clogging of the blood purifier 120 based on the blood marker detection time.

[0144] It is also possible to obtain a quantitative relationship between blood marker detection time and the degree of clogging in advance. This allows for an accurate estimation of the degree of dialyzer clogging by measuring the blood marker detection time.

[0145] Furthermore, it is possible to obtain the relationship between blood marker detection time and the degree of clogging for each dialyzer, as the relationship may differ depending on the type of dialyzer.

[0146] Although preferred embodiments of the blood purification device of the present invention have been described above, the present invention is not limited to the embodiments described above and can be modified as appropriate.

[0147] For example, in the second embodiment, the target for estimating the degree of clogging is not limited to the dialyzer. If the blood purifier 120 is equipped with other components for blood purification other than the dialyzer, such as dialysis membranes, those components can be targeted. Clogging can also be estimated in a configuration that measures blood concentration before recirculation. In other words, by detecting blood markers with the venous side measuring means 112M, it is possible to estimate the degree of clogging regardless of whether recirculation occurs.

[0148] The estimation of the degree of clogging described above can be performed without changing the treatment operation of a standard blood purification device. Furthermore, by monitoring membrane clogging over time, it is possible to control filtration or reverse filtration to reflect the clogging situation. In addition, the combination of treatment conditions, dialyzer, and blood circuit differs from patient to patient. By understanding the degree of dialyzer clogging, it becomes possible to perform optimal dialysis that maximizes the characteristics of the dialyzer membrane and is best suited to the patient.

[0149] <1> The method for estimating the degree of clogging in a blood purification device is: In hemodialysis treatment using a blood purifier, A blood marker application step involves applying a predetermined amount of blood marker to circulating blood, A blood marker detection step involves detecting the blood marker from the blood that has passed through the blood purifier, A blood marker detection time acquisition step, which involves obtaining the blood marker detection time, which is the time from the time the blood marker is applied to the time the blood marker is detected. The system includes a clogging degree estimation step, which estimates the degree of clogging of the dialyzer contained in the blood purifier from the blood marker detection time.

[0150] <2> In the blood marker detection step, Blood concentration is obtained over time. The point in time when the blood concentration changes after the application of the blood marker is defined as the point in time when the blood marker is detected. <1> A method for estimating the degree of clogging in the blood purification device described above.

[0151] <3> In the blood marker application step, the application of the blood marker is performed as follows: Injecting replacement fluid into the blood upstream of the aforementioned blood purifier, The method involves flowing replacement fluid in the reverse filtration direction through the dialyzer included in the blood purifier, and This is done by one of the following methods: filtration <1> or <2> A method for estimating the degree of clogging in the blood purification device described above.

[0152] <4> In the above step of estimating the degree of clogging, When the blood marker detection time is long, it is estimated that the degree of clogging of the dialyzer is higher compared to when the blood marker detection time is short. <1> from <3> A method for estimating the degree of clogging in a blood purifier, as described in one of the following:

[0153] <5> A blood purification device consists of a blood purifier and, The arterial line that supplies blood to the aforementioned blood purifier, A venous line that returns the blood purified by the aforementioned blood purifier back to the patient, The blood purifier or the blood marker application means for applying a blood marker to the blood in the arterial line, An arterial measuring means provided in the arterial line for measuring the state of blood flowing through the arterial line, or a venous measuring means provided in the venous line for measuring the state of blood flowing through the venous line, The system comprises the blood marker application means and a control unit for controlling the arterial side measurement means or the venous side measurement means, The control unit estimates the degree of clogging of the blood purifier based on the blood marker detection time, from the time the blood marker is applied to the blood by the blood marker application means until the time the arterial side measuring means or the venous side measuring means detects a change in the state of the blood caused by the application. [Explanation of symbols]

[0154] 100 Blood purification devices 102 Console 110 Blood circuit 111 Arterial line 112 Venous line 113 Drug Line 114 Drainage line 120 Blood Purifiers 121 Container body 130 Dialysate circuit 133 Dialysate feeding section 1331 Dialysis fluid chamber 1332 Bypass Line 1333 Water Removal and Back Filtration Pump 140 Control Unit 150 Infusion pump 152 Infusion line 160 Pressure Monitoring Line 200 Recirculation Rate Measurement Model 202 blood bottles 204 Drainage bottle 220 blood withdrawal lines 222 Return Line 224 Drainage line 226 Recirculation Line 231 First three-way stopcock 232 Second three-way stopcock 233 Third three-way stopcock 240 Metering Pump

Claims

1. In hemodialysis treatment using a blood purifier, A blood marker application step involves applying a predetermined amount of blood marker to circulating blood, A blood marker detection step involves detecting the blood marker from the blood that has passed through the blood purifier, A blood marker detection time acquisition step, which involves obtaining the blood marker detection time, which is the time from the time the blood marker is applied to the time the blood marker is detected. A method for estimating the degree of clogging in a blood purifier, comprising: a clogging degree estimation step of estimating the degree of clogging of the dialyzer contained in the blood purifier from the blood marker detection time.

2. In the blood marker detection step, Blood concentration is obtained over time. A method for estimating the degree of clogging of a blood purifier according to claim 1, wherein the point in time when the blood concentration changes after the application of the blood marker is defined as the point in time when the blood marker is detected.

3. In the blood marker application step, the application of the blood marker is performed as follows: Injecting replacement fluid into the blood upstream of the aforementioned blood purifier, The method involves flowing replacement fluid in the reverse filtration direction through the dialyzer included in the blood purifier, and A method for estimating the degree of clogging of a blood purifier according to claim 1 or 2, which is performed by one of the following: filtering.

4. In the above step of estimating the degree of clogging, A method for estimating the degree of clogging in a blood purifier according to claim 1 or 2, wherein when the blood marker detection time is long, it is estimated that the degree of clogging in the dialyzer is higher than when the blood marker detection time is short.

5. A blood purifier, The arterial line that supplies blood to the aforementioned blood purifier, A venous line that returns the blood purified by the aforementioned blood purifier back to the patient, The blood purifier or the blood marker application means for applying a blood marker to the blood in the arterial line, An arterial measuring means provided in the arterial line for measuring the state of blood flowing through the arterial line, or a venous measuring means provided in the venous line for measuring the state of blood flowing through the venous line, The system comprises the blood marker application means and a control unit for controlling the arterial side measurement means or the venous side measurement means, A blood purification device in which the control unit estimates the degree of clogging of the blood purifier based on the blood marker detection time from the time the blood marker is applied to the blood by the blood marker application means to the time the arterial side measuring means or the venous side measuring means detects a change in the state of the blood caused by the application.

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