Blood circulation monitoring method, dialysis device, and computer-readable non-transitory recording medium

Abstract

This invention provides a technique for detecting leakage in extracorporeal blood circulation while mitigating the increase in the cost of dialysis devices. The dialysis device (1) includes an arterial blood circuit (110), a dialyzer (103), and a venous blood circuit (120). The dialysis device (1) detects abnormalities based on the difference between the theoretical and measured values ​​of blood concentration in the venous blood circuit (120). The theoretical value of blood concentration in the venous blood circuit (120) is determined based on the blood concentration in the arterial blood circuit (110), blood flow rate, and the water removal rate in the dialyzer (103).

Description

Technical Field

[0001] This disclosure relates to the monitoring of blood circulation patterns outside the body. Background Technology

[0002] In the past, various techniques have been proposed for extracorporeal blood circulation in dialysis treatments. For example, Patent Document 1 (Patent Publication No. 2015-141621) discloses a method for calibrating blood concentration measurements that include the offset of extracorporeal blood circulation due to differences in resin tubes.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Republished 2015-141621 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] Dialysis treatment uses a sealed system for water removal; however, in this system, over- or under-removal can occur due to leaks in the solenoid valves, etc. These issues can be detected by incorporating a mechanism in the dialysis unit to detect leaks in each solenoid valve. However, adding such a mechanism may increase the cost of the dialysis unit. Furthermore, leaks occurring outside the solenoid valves, such as those in the water pump, cannot be detected by this mechanism.

[0008] This disclosure was conceived in view of the actual circumstances involved, and its purpose is to provide a technique for detecting leaks in extracorporeal blood circulation while controlling cost increases in dialysis devices.

[0009] Technical means for solving technical problems

[0010] According to certain aspects of this disclosure, a blood circulation monitoring method is provided, which is a computer-executed method, comprising: acquiring physical quantities in an arterial-side blood circuit for injecting blood into a blood purifier; acquiring physical quantities in a venous-side blood circuit for draining blood from the blood purifier; acquiring, using at least one of the physical quantities acquired in the arterial-side blood circuit and the venous-side blood circuit, a theoretical value for determining whether an abnormality exists in the mechanism supplying dialysate to the blood purifier; determining the occurrence of an abnormality based on the theoretical value, the physical quantities in the arterial-side blood circuit or the venous-side blood circuit, and a given threshold; and, if an abnormality is determined to have occurred, performing a procedure for handling the abnormality.

[0011] The step of obtaining the theoretical value may include calculating the theoretical value of the blood concentration index in the venous blood circuit based on the blood concentration index obtained in the arterial blood circuit. The step of determining an anomaly may include determining that an anomaly has occurred if the difference between the blood concentration index obtained in the venous blood circuit and the theoretical value is above a given threshold.

[0012] The step of obtaining the theoretical value may include deriving the theoretical value of the blood flow in the venous blood circuit based on the blood flow obtained in the arterial blood circuit. The step of determining an anomaly may include determining that an anomaly has occurred if the difference between the blood flow obtained in the venous blood circuit and the theoretical value is above a given threshold.

[0013] The blood flow rate obtained in the arterial side blood circuit can also be obtained from the flow rate of a blood pump installed to deliver blood in the arterial side blood circuit.

[0014] Theoretical values ​​can also be based on the water removal rate in a blood purifier.

[0015] The process of obtaining theoretical values ​​may include storing the blood concentration in the arterial or venous blood circuit as a theoretical value in a storage device at the first time interval when the dialysate pump used to cause the dialysate to be discharged from the blood purifier is not in operation.

[0016] The steps for determining the occurrence of an anomaly may include the following: if the difference between the theoretical value and the indicator obtained at a second time when the dialysate pump is not in operation is above a given threshold, an anomaly is determined to have occurred.

[0017] An abnormality assessment procedure can be performed before dialysis treatment using a blood purification device begins.

[0018] The step of obtaining the theoretical value may include obtaining a first difference, which is the difference between the blood concentration index in the arterial blood circuit and the blood concentration index in the venous blood circuit obtained at a first timing. The step of determining the occurrence of an anomaly may include obtaining a second difference, which is the difference between the blood concentration index in the arterial blood circuit and the blood concentration index in the venous blood circuit obtained at a second timing, and determining that an anomaly has occurred if the difference between the first difference and the second difference is above a given threshold.

[0019] The water removal rate in the blood purifier can be equal during the first and second time intervals.

[0020] Blood concentration indicators can include blood cell ratio.

[0021] According to another aspect of this disclosure, a dialysis apparatus is provided, including a blood purifier, an arterial blood circuit for injecting blood into the blood purifier, a venous blood circuit for allowing blood to flow out of the blood purifier, a blood pump for delivering blood from the arterial blood circuit, and a controller for controlling the operation of the blood pump, the controller being configured to implement the above-described blood circulation monitoring method.

[0022] According to another aspect of this disclosure, a computer-readable non-temporary recording medium is provided that stores a program, which is executed by a computer, thereby enabling the computer to implement the above-described blood circulation monitoring method.

[0023] Invention Effects

[0024] According to this disclosure, physical quantities in the arterial blood circuit and / or the venous blood circuit are used to detect the occurrence of abnormalities such as leakage in the extracorporeal blood circulation. Attached Figure Description

[0025] Figure 1 This is a diagram illustrating an example of the structure of a dialysis device.

[0026] Figure 2 This is a diagram illustrating an example of the formula relating Ht(A) and Ht(V).

[0027] Figure 3 This is a flowchart of the process performed by the dialysis apparatus 1 to detect abnormalities according to the first method.

[0028] Figure 4 This is a diagram illustrating a second method for detecting anomalies related to leaks.

[0029] Figure 5 This is a flowchart of the process performed by dialysis device 1 to detect abnormalities according to the second method.

[0030] Figure 6 This is a diagram used to illustrate a third method for detecting anomalies related to leaks.

[0031] Figure 7 This is a flowchart of the process performed by dialysis device 1 to detect abnormalities according to a third method.

[0032] Figure 8 This is a diagram illustrating a fourth method for detecting anomalies related to leaks.

[0033] Figure 9 This is a flowchart of the process performed by dialysis device 1 to detect abnormalities according to the fourth method. Detailed Implementation

[0034] Hereinafter, one embodiment of the dialysis apparatus will be described with reference to the accompanying drawings. In the following description, the same reference numerals will be used to denote the same parts and structural elements. Their names and functions are also the same. Therefore, these detailed descriptions will not be repeated.

[0035] [1. Structure of a dialysis apparatus]

[0036] Figure 1 This is a diagram illustrating an example of the structure of a dialysis device. (As shown...) Figure 1 As shown, the dialysis apparatus 1 includes a dialysis unit 100 and a controller 200.

[0037] (Dialysis Unit 100)

[0038] The dialysis unit 100 includes a dialyzer 103, an arterial blood circuit 110 connecting the patient's artery to the separator 103, and a venous blood circuit 120 connecting the patient's vein to the separator 103. The dialyzer 103 is an example of a blood purifier. The dialysis apparatus 1 also includes a blood pump 102 for delivering blood to the dialyzer 103 in the arterial blood circuit 110, a concentration measuring device 101 for measuring the blood concentration in the arterial blood circuit 110, and a concentration measuring device 104 for measuring the blood concentration in the venous blood circuit 120.

[0039] The dialysis apparatus 1 also includes a dehydration mechanism 150 for supplying dialysate to the dialyzer 103. In the dehydration mechanism 150, dialysate is supplied to the dialyzer 103 via an upstream dialysate line 151 and discharged from the dialyzer 103 via a downstream dialysate line 152. The dehydration mechanism 150 includes a dialysate pump 155 for facilitating the discharge of dialysate from the dialyzer 103. Various supply methods can be employed for supplying dialysate by the dehydration mechanism 150.

[0040] (Controller 200)

[0041] The controller 200 includes a processor 201, a storage device 202, an input device 203, an output device 204, and an input / output interface 205.

[0042] The processor 201 executes a program stored in the storage device 202. The storage device 202 is composed of a hard disk drive or a solid-state drive, etc. The storage device 202 can store various data used for executing the program.

[0043] The input device 203 is used by the user to input information into the dialysis device 1, for example, via a keyboard, mouse, hardware buttons and / or touch sensors.

[0044] The output device 204 is used to output information from the dialysis device 1, for example, through a display, an LED (Light Emitting Diode) lamp and / or a speaker.

[0045] Input / output interface 205 is used to output data from various elements within the dialysis unit 100 to the controller 200 and to output data from the controller 200 to various elements within the dialysis unit 100. In one example, the controller 200 outputs control commands to the blood pump 102 via input / output interface 205. In another example, the controller 200 acquires various measurement results from concentration measuring devices 101 and 104 via input / output interface 205.

[0046] In this embodiment, the controller 200 can control the dialysis unit 100 and detect leak-related anomalies in the dehydration mechanism 150. That is, the controller 200 can detect anomalies when leaks occur at various points including the solenoid valves of the dehydration mechanism 150 and the dialysate pump 155.

[0047] [2. Water removal in dialysis equipment]

[0048] Next, the removal of water from the blood in dialysis apparatus 1 will be described. In the following description, the names of the physical quantities associated with dialysis apparatus 1 are defined as follows.

[0049] “BP” indicates the flow rate of blood pump 102.

[0050] “Ht(A)” represents the blood concentration on the arterial side (A side). In this embodiment, the blood cell ratio is used as an example of an indicator of blood concentration. Alternatively, all other types of indicators can be used as indicators of blood concentration.

[0051] “Ht(V)” indicates the blood concentration on the venous side (V side).

[0052] “QB(A)” indicates the blood flow on the arterial side (A side).

[0053] “QB(V)” indicates the blood flow on the venous side (V side).

[0054] “QD” indicates the flow rate of dialysate delivered from the dehydration unit 150 to the dialyzer 103.

[0055] “UF” indicates the rate of water removal from the blood in dialyzer 103 (per unit of water removed).

[0056] In dialysis apparatus 1, the dehydration unit 150 delivers dialysate at a flow rate of "QD" to dialyzer 103 and discharges a solution at a flow rate of "QD+UF" (a mixture of dialysate and solution contained in the patient's blood) from dialyzer 103. Thus, a solution at a flow rate of "UF" is removed from the patient's blood.

[0057] More specifically, in dialysis apparatus 1, blood pump 102 delivers blood at a flow rate of QB(A) per unit time from the patient's arm artery via arterial-side blood circuit 110 to dialyzer 103. Meanwhile, dialysate at a flow rate of QD per unit time is supplied to the inlet of dialysate line 151 upstream of dialyzer 103. Based on the concentration gradient, water at a flow rate of UF per unit time is removed from the blood passing through the hollow fibers of dialyzer 103 into the dialysate flowing around the hollow fibers of dialyzer 103. Then, the blood with water removed at a flow rate of QB(V) per unit time is returned to the vein in the patient's arm via venous-side blood circuit 120. The removed water at a flow rate of UF, along with the dialysate, is discharged from dialyzer 103 via downstream dialysate line 152.

[0058] [3. Overview of the First Method]

[0059] A first method for detecting leak-related anomalies will be described. In this first method, the dialysis apparatus 1 detects the anomaly based on the difference between the theoretical and measured values ​​of the blood concentration in the venous-side blood circuit 120. The theoretical value of the blood concentration in the venous-side blood circuit 120 is determined based on the blood concentration in the arterial-side blood circuit 110, the blood flow rate, and the water removal rate in the dialyzer 103.

[0060] Figure 2 This is a diagram illustrating an example of an expression representing the relationship between Ht(A) and Ht(V). For example... Figure 2 As shown in Chinese equation (1), Ht(V) can be expressed as the product of Ht(A) and QB(A) divided by "QB(A)-UF".

[0061] In dialysis device 1, UF and QB(A) are input as setpoints by the user (e.g., a doctor or other medical worker) or pre-registered. Controller 200 controls blood pump 102 based on the setpoint of QB(A) and dialysate pump 155 based on the setpoint of UF.

[0062] The controller 200 obtains the measured value of Ht(A) and the set values ​​of UF and QB(A) from the concentration measuring device 101, and calculates the theoretical value of Ht(V) according to formula (1). Then, the controller 200 obtains the measured value of Ht(V) from the concentration measuring device 104, compares the measured value of Ht(V) with the theoretical value, and determines that an abnormality has occurred in the water removal mechanism 150 if the difference between the theoretical value and the measured value is above a given threshold.

[0063] A threshold can be set for each scenario in which the technology involved in this embodiment is applied. In one implementation example, the threshold is a pre-set value registered in the dialysis apparatus 1. In other implementation examples, the threshold can be defined based on the theoretical value calculated at that time (e.g., 10% of the theoretical value). That is, for example, if the difference between the measured value and the theoretical value is more than 10% of the theoretical value, the controller 200 can determine that an abnormality has occurred in the water removal mechanism 150.

[0064] [4. The flow of the first method]

[0065] Figure 3 This is a flowchart of the process performed by the dialysis apparatus 1 to detect an abnormality according to the first method. In one implementation example, the dialysis apparatus 1 implements this by causing the processor 201 to execute a given program. Figure 3 The dialysis device 1 may include dedicated circuits such as ASIC (Application Specific Integrated Circuit) or FPGA (Field-Programmable Gate Array), and as a function of this dedicated circuit, it can realize... Figure 3 The processing.

[0066] Dialysis device 1 can be started, for example, at regular time intervals (e.g., every 10 seconds) during dialysis treatment. Figure 3 The process involves controlling the operation of the blood pump 102 and the dialysate pump 155 according to set values ​​during dialysis treatment. The set values ​​for both the blood pump 102 and the dialysate pump 155 can change over time during the dialysis treatment.

[0067] Reference Figure 3 In step S100, the dialysis apparatus 1 obtains the measured value of Ht(A) from the concentration measuring device 101.

[0068] In step S102, the dialysis apparatus 1 obtains the measured value of Ht(V) from the concentration measuring device 104.

[0069] In step S104, the dialysis apparatus 1 uses the measured value of Ht(A) obtained in step S100 and the set values ​​of QB(A) and UF to calculate the theoretical value of Ht(V) according to equation (1).

[0070] In step S106, the dialysis apparatus 1 determines whether the difference between the theoretical value of Ht(V) calculated in step S106 and the measured value of Ht(V) obtained in step S102 is above a predetermined threshold. When the dialysis apparatus 1 determines that the difference is less than the threshold ("No" in step S106), it returns control to step S100. Thus, for example, after a certain period of time since the last execution of step S100, the dialysis apparatus 1 executes the control of step S100 again. When the dialysis apparatus 1 determines that the difference is above the threshold ("Yes" in step S106), it advances control to step S108.

[0071] In step S108, the dialysis device 1 stops the blood pump 102.

[0072] In step S110, the dialysis apparatus 1 stops the dialysate pump 155.

[0073] In step S112, dialysis device 1 notifies of an abnormality and the process ends. Figure 3 The processing of notifications. One example is the display of information on a monitor, which is an example of output device 204. Another example is the output of sound from a speaker, which is an example of output device 204. Yet another example is the sending of notifications to external devices (such as mobile terminals held by medical personnel).

[0074] In the first method described above, stopping the blood pump 102 (step S108), stopping the dialysate pump 155 (step S110), and notifying of the abnormality (step S112) are examples of procedures for handling abnormal operations.

[0075] [5. Overview of the Second Method]

[0076] Figure 4 This is a diagram illustrating a second method for detecting anomalies related to leaks. (See diagram for example.) Figure 4 As shown, the dialysis apparatus 1 may also include a flow meter 190. The flow meter 190 detects the flow rate (flow rate per unit time) of blood in the venous side blood circuit 120.

[0077] The flow meter 190 is implemented, for example, by an ultrasonic flow meter, but it can also be a device that measures blood flow rate in other ways. The controller 200 acquires the measured value of QB(V) from the flow meter 190.

[0078] In the dialysis device 1, the relationship between the blood flow in the arterial blood circuit 110 and the blood flow in the venous blood circuit 120 can be expressed as the following formula (2).

[0079] QB(V)=QB(A)-UF...(2)

[0080] In the second method, the dialysis apparatus 1 calculates the theoretical value of QB(V) according to equation (2) by obtaining the set values ​​of the blood pump 102 and the dialysate pump 155 as the respective values ​​of QB(A) and UF. Then, when the difference between the measured value of QB(V) and the theoretical value of QB(V) is above a given threshold, the dialysis apparatus 1 determines that an abnormality has occurred in the water removal mechanism 150.

[0081] In one implementation, the threshold is a pre-set value registered in the dialysis apparatus 1. In other implementations, the threshold can be defined based on a theoretical value calculated at that time (e.g., a value set as 10% of the theoretical value). That is, for example, if the difference between the measured value and the theoretical value is greater than 10% of the theoretical value, the controller 200 can determine that an anomaly has occurred in the dehydration mechanism 150.

[0082] [6. The process of the second method]

[0083] Figure 5 This is a flowchart of the process performed by the dialysis apparatus 1 to detect abnormalities according to the second method. In one implementation example, the dialysis apparatus 1 implements this by having the processor 201 execute a given program. Figure 5 The dialysis device 1 may include dedicated circuitry such as ASIC or FPGA, and as a function of this dedicated circuitry, it can achieve... Figure 5 The processing.

[0084] Dialysis device 1 can be started, for example, at regular time intervals (e.g., every 10 seconds) during dialysis treatment. Figure 5 The process involves controlling the operation of the blood pump 102 and the dialysate pump 155 according to set values ​​during dialysis treatment. The set values ​​for both the blood pump 102 and the dialysate pump 155 can change over time during the dialysis treatment.

[0085] Reference Figure 5 In step S200, the dialysis device 1 reads the set value of BP.

[0086] In step S202, the dialysis device 1 reads the UF setting value.

[0087] In step S204, the dialysis apparatus 1 uses the BP and UF read in steps S200 and S202 to calculate the theoretical value of QB(V) according to equation (2). At this time, the dialysis apparatus 1 uses BP as the measured value of QB(A).

[0088] In step S206, the dialysis apparatus 1 obtains a measured value of QB(V) from the flow meter 190 and compares this measured value of QB(V) with the theoretical value of QB(V) calculated in step S204. Then, the dialysis apparatus 1 determines whether the difference between these measured values ​​and the theoretical value is above a given threshold.

[0089] When the dialysis device 1 determines that the difference is less than the threshold ("No" in step S106), control returns to step S200. Thus, for example, after a certain period of time since the last step S200, the dialysis device 1 executes the control of step S200 again. When the dialysis device 1 determines that the difference is greater than the threshold ("Yes" in step S206), control proceeds to step S208.

[0090] In step S208, the dialysis device 1 stops the blood pump 102.

[0091] In step S210, the dialysis apparatus 1 stops the dialysate pump 155.

[0092] In step S212, the dialysis device 1 notifies of an error and terminates. Figure 5 The processing of notifications. One example is the display of information on a monitor, which is an example of output device 204. Another example is the output of sound from a speaker, which is an example of output device 204. Yet another example is the sending of notifications to external devices (e.g., mobile terminals carried by healthcare workers).

[0093] In the second method described above, stopping the blood pump 102 (step S208), stopping the dialysate pump 155 (step S210), and notifying of abnormalities (step S212) are examples of procedures for handling abnormal operations.

[0094] [7. Overview of the Third Method]

[0095] Next, the third method will be described. In the third method, the dialysis device 1 detects abnormalities based on changes in the difference between the measured and theoretical values ​​of blood concentration.

[0096] For example, in dialysis apparatus 1, the arterial blood circuit 110 is connected to the patient's artery, the venous blood circuit 120 is connected to the patient's vein, and the dehydration mechanism 150 is connected to the dialyzer 103. In this state, the blood pump 102 and the dialysate pump 155 are not yet activated. That is, this state is an example of the state before the start of dialysis treatment, such that if the blood pump 102 and the dialysate pump 155 are activated, dialysis treatment will begin.

[0097] In this state, it is assumed that there is virtually no blood flow, and the patient's fluid volume in the blood within the arterial blood circuit 110 and the venous blood circuit 120 remains unchanged. Therefore, in this state, when the blood concentration in the arterial blood circuit 110 or the venous blood circuit 120 changes, the likelihood of abnormalities such as leakage in the water removal mechanism 150 is higher.

[0098] In the third method, the dialysis apparatus 1 is maintained in the aforementioned state (at least without the dialysate pump 155 being driven), and the blood concentration within the arterial blood circuit 110 is measured at a first time interval and a second time interval, respectively. If the difference between the blood concentration measured at the first time interval and the blood concentration measured at the second time interval is above a given threshold, the dialysis apparatus 1 determines that an abnormality such as a leak has occurred in the water removal mechanism 150. In this case, the blood concentration measured at the first time interval is used as an ideal value relative to the blood concentration measured at the second time interval.

[0099] Figure 6 This is a diagram used to illustrate a third method for detecting anomalies related to leaks. Figure 6 The diagram illustrates an example of how blood concentration changes over time in the aforementioned state (at least the state where the dialysate pump 155 is not activated). Line L11 represents the ideal value of blood concentration, and line L12 represents an example of the measured blood concentration when an abnormality occurs. When the blood concentration C1 measured at time T2 (second timing) changes by more than a threshold relative to the blood concentration C0 measured at time T1 (first timing), the dialysis apparatus 1 determines that an abnormality has occurred.

[0100] In one implementation, the threshold is a pre-set value registered in the dialysis apparatus 1. In other implementations, the threshold can be defined based on a theoretical value calculated at that time (e.g., 10% of the theoretical value). That is, for example, if the difference between the measured value and the theoretical value is greater than 10% of the theoretical value, the controller 200 can determine that an abnormality has occurred in the dehydration mechanism 150.

[0101] [8. The process of the third method]

[0102] Figure 7This is a flowchart of the process performed by dialysis apparatus 1 to detect abnormalities according to a third method. In one implementation example, dialysis apparatus 1 achieves this by having processor 201 execute a given program. Figure 7 The dialysis device 1 may include dedicated circuitry such as ASIC or FPGA, and as a function of this dedicated circuitry, it can achieve... Figure 7 The processing.

[0103] Reference Figure 7 In step S300, the dialysis apparatus 1 acquires the concentration measurement value (Ht(A)) of the concentration measuring device 101 at time T1.

[0104] In step S302, the dialysis device 1 stores the Ht(A) obtained in step S300 in the storage device 202.

[0105] In step S304, the dialysis apparatus 1 acquires the concentration measurement value (Ht(A)) of the concentration measuring device 101 at time T2.

[0106] In the third method, time T1 and time T2 can be set for each scenario in which the third method is applied. In one embodiment, time T1 and time T2 can be the period before the start of dialysis treatment, and time T2 can be set as the time at which a significant difference occurs relative to time T1 in the event of a leak in the water removal unit 150.

[0107] In step S306, the dialysis device 1 determines whether the difference between Ht(A) at time T1 stored in step S302 and Ht(A) obtained in step S304 is above a given threshold. When the dialysis device 1 determines that the difference is less than the given threshold ("No" in step S306), dialysis treatment begins in step S308 and ends. Figure 7 The process is then initiated. Thus, in the dialysis apparatus 1, the action of driving the dialysate pump 155 for dialysis treatment begins. On the other hand, when the dialysis apparatus 1 determines that the difference is above a given threshold ("Yes" in step S306), control proceeds to step S310.

[0108] In step S310, the dialysis device 1 notifies of the abnormality via display, sound, and / or notification to external devices, and then terminates the process. Figure 7 The handling of the exception. The exception notification in step S310 is an example of a procedure used for handling exceptions.

[0109] As Figure 7In handling this situation, the dialysis unit 1 detects an anomaly while the dialysate pump 155 is stopped, and notifies the user of the anomaly if the anomaly is detected (if the difference in step S306 is above a given threshold). The user (e.g., a healthcare worker) can respond to the anomaly notification by checking the dehydration mechanism 150 containing the dialysate pump 155 and, if necessary, repairing or replacing the solenoid valve.

[0110] In the above description, the blood concentration in the arterial blood circuit 110 is used to detect abnormalities, but the blood concentration in the venous blood circuit 120 can also be used. That is, the dialysis device 1 can obtain measurement values ​​from the concentration measuring device 104 at times T1 and T2 respectively. Then, if the difference between these measurement values ​​is less than a predetermined threshold, the dialysis device 1 starts dialysis treatment as if there is no abnormality; if it is above the threshold, an abnormality can be notified.

[0111] In the above description, dialysis device 1 performs [the procedure] before dialysis treatment begins. Figure 7 The system processes the fluid, and if no abnormalities are detected, dialysis treatment begins. Additionally, even during dialysis treatment, the dialysis unit 1 can stop the dialysate pump 155 to perform... Figure 7 The process involves detecting abnormalities. In this case, if an abnormality is detected, the dialysis device 1 can perform a procedure to interrupt dialysis treatment (e.g., stop the blood pump 102) before step S310.

[0112] [9. Overview of the Fourth Method]

[0113] Next, the fourth method will be described. In the fourth method, the dialysis device 1 detects abnormalities based on changes in the difference in blood concentration between the arterial and venous sides.

[0114] More specifically, in dialysis apparatus 1, when the water removal rate UF is constant, the blood concentration on the arterial side and the blood concentration on the venous side are theoretically constant. However, in the event of a leak in the water removal mechanism 150, the leaked water is discharged from the dialyzer 103, causing the blood concentration on the downstream side of dialyzer 103, i.e., the venous side, to increase more than assumed. Consequently, the difference in blood concentration between the arterial and venous sides is larger than theoretically expected. When the change in the difference in blood concentration between the arterial and venous sides exceeds a given threshold, dialysis apparatus 1 notifies of an anomaly.

[0115] In one implementation, the threshold is a pre-set value registered in the dialysis device 1. In other implementations, the threshold can be defined based on a difference at a given time (e.g., a value set as 10% of the difference before or at the start of dialysis treatment). That is, for example, if the difference in blood concentration between the arterial and venous sides changes by more than 10% compared to the difference at the start of dialysis treatment, the controller 200 can determine that the dehydration mechanism 150 has malfunctioned.

[0116] Figure 8 This is a diagram illustrating a fourth method for detecting anomalies related to leaks. Figure 8 The image shows the changes in blood concentration over time on the arterial and venous sides. Figure 8 At time T21, the difference in blood concentration between the arterial and venous sides is D1, but at time T22, the difference in blood concentration between the arterial and venous sides is D2, which is greater than D1. If the difference between D1 and D2 is above a given threshold, the dialysis device 1 can detect an abnormality based on the change in the difference from D1 to D2.

[0117] [10. The process of the fourth method]

[0118] Figure 9 This is a flowchart of the process performed by dialysis apparatus 1 according to the fourth method to detect abnormalities. In one implementation example, dialysis apparatus 1 achieves this by having processor 201 execute a given program. Figure 9 The dialysis device 1 may include dedicated circuitry such as ASIC or FPGA, and as a function of this dedicated circuitry, it can achieve... Figure 9 The processing.

[0119] For example, dialysis device 1 starts as soon as dialysis treatment begins. Figure 9 The process involves controlling the operation of the blood pump 102 and the dialysate pump 155 according to set values ​​during dialysis treatment. The set values ​​for both the blood pump 102 and the dialysate pump 155 can change over time during the dialysis treatment.

[0120] Reference Figure 9 In step S400, the dialysis apparatus 1 obtains the measured value (Ht(A)) from the concentration measuring device 101.

[0121] In step S402, the dialysis apparatus 1 obtains the measured value (Ht(V)) from the concentration measuring device 104.

[0122] In step S404, the dialysis apparatus 1 calculates the difference D1 between Ht(A) obtained in step S400 and Ht(V) obtained in step S402. After this, after a predetermined time (e.g., 10 seconds), the dialysis apparatus 1 proceeds to step S406.

[0123] In step S406, the dialysis apparatus 1 obtains the measured value (Ht(A)) from the concentration measuring device 101.

[0124] In step S408, the dialysis apparatus 1 obtains the measured value (Ht(V)) from the concentration measuring device 104.

[0125] In step S410, the dialysis apparatus 1 calculates the difference D2 between Ht(A) obtained in step S406 and Ht(V) obtained in step S408.

[0126] In step S412, the dialysis apparatus 1 determines whether the difference between D1 and D2 is above a given threshold. If the dialysis apparatus 1 determines that the difference is less than the given value ("No" in step S412), it advances control to step S414; if the dialysis apparatus 1 determines that the difference is above the given value ("Yes" in step S412), it advances control to step S416.

[0127] In step S414, the dialysis apparatus 1 stores the value calculated as difference D2 in step S410 as D1 in the storage device 202, and returns control to step S406. Then, in step S412, D1 stored in the storage device 202 in step S414 is compared with D2 calculated in step S410.

[0128] In step S416, the dialysis device 1 stops the blood pump 102.

[0129] In step S418, the dialysis apparatus 1 stops the dialysate pump 155.

[0130] In step S420, the dialysis device 1 notifies of an abnormality and terminates. Figure 9 The processing of notifications. One example is the display of information on a monitor, which is an example of output device 204. Another example is the output of sound from a speaker, which is an example of output device 204. Yet another example is the sending of notifications to external devices (e.g., mobile terminals carried by healthcare workers).

[0131] In the fourth method described above, stopping the blood pump 102 (step S416), stopping the dialysate pump 155 (step S418), and notifying of abnormalities (step S420) are examples of procedures for handling abnormal operations.

[0132] In the fourth method, the difference between the blood concentration on the arterial side (Ht(A)) and the blood concentration on the venous side (Ht(V)) is calculated at regular intervals. If the calculated difference changes by more than a given threshold compared to the previously calculated difference, it is judged as an abnormality and the procedure for abnormal action is executed.

[0133] Alternatively, in the fourth method, step S414 can be omitted. In this case, in step S412, D2 calculated in step S410 is compared with D1 calculated in step S404. That is, D2 calculated at predetermined time intervals is compared with... Figure 9 The D1 calculated at the beginning of the treatment (e.g., D1 at the start of dialysis treatment) is compared with the D1 calculated at the beginning of the treatment.

[0134] [11. Controller]

[0135] In this implementation method, refer to Figure 3 , Figure 5 , Figure 7 and Figure 9 The described process is achieved by the controller 200 of the dialysis apparatus 1 using elements such as the concentration measuring device 101 within the dialysis unit 100. In this sense, the controller 200 can be implemented remotely from the dialysis apparatus 1. That is, referring to… Figure 3 , Figure 5 , Figure 7 and Figure 9 The described process can communicate with the various elements of the dialysis apparatus 1, and a computer located outside the dialysis apparatus 1 can function as a controller 200.

[0136] All descriptions of the embodiments disclosed herein should be considered illustrative rather than limiting. The scope of the invention is defined by the scope of the claims, not by the foregoing description, and also includes all modifications within the scope of the claims. Furthermore, the invention described in the embodiments and variations is intended to be practiced individually or in combination whenever possible.

[0137] Label Explanation

[0138] 1. Dialysis apparatus, 100. Dialysis unit, 101, 104. Concentration measuring devices, 102. Blood pump, 103. Dialyzer, 110. Arterial blood circuit, 120. Venous blood circuit, 150. Water removal mechanism, 151. Upstream dialysate line, 152. Downstream dialysate line, 155. Dialysate pump, 190. Flow meter, 200. Controller.

Claims

1. A method for monitoring blood circulation, wherein the method is executed by a computer, characterized in that, include: Steps for obtaining physical quantities in the arterial side blood circuit used to inject blood into a blood purifier; The step of obtaining physical quantities in the venous-side blood circuit used to allow blood to flow out of the blood purifier; The steps of obtaining theoretical values ​​of the physical quantities in the venous-side blood circuit, used to determine whether there is an abnormality in the mechanism supplying dialysate to the blood purifier, using the physical quantities acquired in the arterial-side blood circuit; and The steps for determining the occurrence of an abnormality are based on the theoretical value, the physical quantities in the venous blood circuit, and the given threshold.

2. The blood circulation monitoring method as described in claim 1, characterized in that, The step of obtaining the theoretical value includes calculating the theoretical value of the blood concentration index in the venous side blood circuit based on the blood concentration index obtained in the arterial side blood circuit. The step of determining the occurrence of the abnormality includes the following: if the difference between the blood concentration index obtained in the venous blood circuit and the theoretical value is above a given threshold, it is determined that an abnormality has occurred.

3. The blood circulation monitoring method as described in claim 1, characterized in that, The step of obtaining the theoretical value includes deriving the theoretical value of the blood flow in the venous side blood circuit based on the blood flow obtained in the arterial side blood circuit. The step of determining the occurrence of the abnormality includes the following: if the difference between the blood flow obtained in the venous blood circuit and the theoretical value is above a given threshold, it is determined that an abnormality has occurred.

4. The blood circulation monitoring method as described in claim 3, characterized in that, The blood flow rate obtained in the arterial side blood circuit is obtained using the flow rate of a blood pump installed to deliver blood in the arterial side blood circuit.

5. The blood circulation monitoring method according to any one of claims 2 to 4, characterized in that, The theoretical value is also based on the water removal rate in the blood purifier.

6. The blood circulation monitoring method as described in claim 1, characterized in that, The step of obtaining the theoretical value includes storing an index of the blood concentration in the arterial or venous blood circuit, obtained at a first time interval during which the dialysate pump used to cause dialysate to be discharged from the blood purifier is not in operation, as the theoretical value in a storage device. The step of determining the occurrence of the anomaly includes determining that an anomaly has occurred if the difference between the theoretical value and the index obtained at a second time when the dialysate pump is not in operation is above a given threshold.

7. The blood circulation monitoring method as described in claim 6, characterized in that, Also includes: The steps to obtain the physical quantities in the arterial blood circuit used to inject blood into the blood purifier before the start of dialysis treatment; The steps of acquiring physical quantities in the venous-side blood circuit used to allow blood to flow from the blood purifier before the start of dialysis treatment; and The steps for determining the occurrence of an abnormality are based on the physical quantities obtained in the arterial blood circuit before the start of dialysis treatment, the physical quantities in the venous blood circuit used to determine whether there is an abnormality in the mechanism for supplying dialysate to the blood purifier, the physical quantities in the venous blood circuit obtained before the start of dialysis treatment, and a given threshold.

8. The blood circulation monitoring method as described in claim 1, characterized in that, The step of obtaining the theoretical value includes obtaining a first difference, which is a measure of the blood concentration in the arterial blood circuit and the blood concentration in the venous blood circuit, obtained at a first timing interval. The step of determining the occurrence of the abnormality includes obtaining a second difference, which is the difference between the blood concentration index in the arterial blood circuit and the blood concentration index in the venous blood circuit obtained in the second timing, and determining that an abnormality has occurred if the difference between the first difference and the second difference is above a given threshold.

9. The blood circulation monitoring method as described in claim 8, characterized in that, During the first and second timing periods, the water removal rate in the blood purifier is equal.

10. The blood circulation monitoring method according to any one of claims 2 and 6 to 9, characterized in that, The indicators of blood concentration include the blood cell ratio.

11. A dialysis device, characterized in that, include: Blood purifier; The arterial side blood circuit used to inject blood into the blood purifier; A venous-side blood circuit for allowing blood to flow out of the blood purifier; A blood pump designed to deliver blood from the arterial side blood circuit; and A controller that controls the operation of the blood pump. The controller is configured to implement the blood circulation monitoring method as described in any one of claims 1 to 4 and 6 to 9.

12. A storage program recording medium, wherein the recording medium is a computer-readable non-temporary recording medium, characterized in that, The program is executed by a computer, thereby enabling the computer to implement the blood circulation monitoring method as described in any one of claims 1 to 4 and 6 to 9.

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