Blood pressure decrease prediction device, monitoring system, and program

Abstract

To provide a blood pressure reduction prediction device, a monitoring system, and a program capable of predicting the occurrence of blood pressure reduction during dialysis.SOLUTION: The decrease in blood pressure prediction device 1 includes a blood flow rate acquiring section 11 that acquires a blood flow rate value that is a value of a blood flow rate from a blood flow measuring device 4 that continuously measures the blood flow rate at a peripheral site of a patient P during dialysis, a rate-of-change calculating section 13 that calculates a rate of change of the blood flow rate based on the blood flow rate value acquired by the blood flow rate acquiring section 11, and a notification controller 14 that performs notification indicating a tendency to lower blood pressure.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a blood pressure decrease prediction device, a monitoring system, and a program. [Background technology]

[0002] It has been reported that a drop in blood pressure in patients undergoing dialysis has a negative impact on their prognosis (see, for example, Non-Patent Documents 1 and 2). Therefore, there is a demand for dialysis treatment that does not cause a drop in blood pressure. The Japanese Society for Dialysis Therapy's "Guidelines for the Evaluation and Treatment of Cardiovascular Complications in Hemodialysis Patients" defines a sudden drop in blood pressure during dialysis as "a drop in systolic blood pressure of 20 mmHg or more during dialysis, or a drop in mean blood pressure of 10 mmHg or more accompanied by symptoms." [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] SHOJI, Tatsuya, et al. Hemodialysis-associated hypotension as an independent risk factor for two-year mortality in hemodialysis patients. Kidney international,2004,66.3:1212-1220. [Non-patent document 2] ZAGER, Philip G., et al. “U” curve association of blood pressure and mortality in hemodialysis patients. Kidney international,1998,54.2:561-569. Summary of the Invention [Problem to be solved by the invention]

[0004] If intradialytic hypotension (IDH) occurs during dialysis, it may be necessary to interrupt dialysis treatment that day. Therefore, it is desirable to predict and deal with the occurrence of intradialytic hypotension in advance so that it does not occur and dialysis treatment does not have to be interrupted.

[0005] Therefore, an object of the present invention is to provide a blood pressure decrease prediction device, a monitoring system, and a program that make it possible to predict in advance the occurrence of a blood pressure decrease during dialysis. [Means for solving the problem]

[0006] The present invention relates to a blood pressure decrease prediction device comprising: a blood flow value acquisition unit that acquires a blood flow value, which is the value of the blood flow, from a blood flow measurement unit that continuously measures the blood flow in a peripheral area of ​​a patient undergoing dialysis; a change rate calculation unit that calculates the rate of change of the blood flow from time series data of the blood flow based on the blood flow value acquired by the blood flow value acquisition unit; and an alarm unit that issues an alarm indicating a blood pressure decrease trend based on the change rate calculated by the change rate calculation unit.

[0007] In the blood pressure decrease prediction device, it is preferable that the notification unit issues a notification indicating a blood pressure decrease tendency when the rate of change calculated by the rate of change calculation unit falls below a predetermined threshold.

[0008] Furthermore, it is preferable that the blood pressure decrease prediction device includes a reference value acquisition unit that acquires a judgment reference value based on the blood flow value acquired by the blood flow value acquisition unit after a predetermined time from the start of dialysis, and the change rate calculation unit calculates the change rate using the judgment reference value acquired by the reference value acquisition unit.

[0009] In the blood pressure decrease prediction device, it is preferable that the change rate calculation unit calculates the change rate over a predetermined time interval using a moving average.

[0010] In the blood pressure decrease prediction device, it is preferable that the blood flow value acquisition unit acquires the blood flow value at an earlobe of the patient.

[0011] The present invention also relates to a blood pressure decrease prediction device comprising: a blood flow value acquisition unit that acquires blood flow values, which are values ​​of blood flow, from a blood flow measurement unit that continuously measures blood flow in a peripheral region of a patient undergoing dialysis; a sign prediction unit that inputs time series data of the blood flow based on the blood flow values ​​acquired by the blood flow value acquisition unit into a learning model and predicts signs of a blood pressure decrease tendency; and a notification unit that issues a notification indicating a blood pressure decrease tendency in accordance with the prediction by the sign prediction unit, wherein the learning model is learned by correlating the time series data of the patient's blood flow values ​​with time series data of their blood pressure state.

[0012] The present invention also relates to a monitoring system comprising at least one of the above-mentioned blood pressure decrease prediction devices and a dialysis machine communicatively connected to the blood pressure decrease prediction device, wherein the blood pressure decrease prediction device comprises a control signal sending unit that sends a control signal to the dialysis machine based on the rate of change calculated by the rate of change calculation unit or the prediction by the sign prediction unit, and the dialysis machine comprises a water removal control unit that controls water removal in accordance with the received control signal.

[0013] The present invention also relates to a program for causing a computer to function as at least one of the above blood pressure decrease prediction devices. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a blood pressure decrease prediction device, a monitoring system, and a program that make it possible to predict in advance the occurrence of a blood pressure decrease during dialysis. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram showing the overall configuration of a monitoring system according to a first embodiment. [Figure 2]FIG. 2 is a diagram showing functional blocks of a blood pressure decrease prediction device and a blood flow measurement device according to the first embodiment. [Figure 3] FIG. 2 is a diagram for explaining thresholds used in processing in the blood pressure decrease prediction device according to the first embodiment. [Figure 4] FIG. 2 is a diagram for explaining thresholds used in processing in the blood pressure decrease prediction device according to the first embodiment. [Figure 5] 4 is a flowchart showing a blood pressure decrease prediction process of the blood pressure decrease prediction device according to the first embodiment. [Figure 6] FIG. 10 is a diagram showing functional blocks of each device used in the monitoring system according to the second embodiment. [Figure 7] 10 is a flowchart showing a blood pressure decrease prediction process of the blood pressure decrease prediction device according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] (First embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [Monitoring System 100] FIG. 1 is a diagram showing the overall configuration of a monitoring system 100 according to the first embodiment. FIG. 2 is a diagram showing functional blocks of the blood pressure decrease prediction device 1 and the blood flow measuring device 4 according to the first embodiment. The monitoring system 100 is a system that predicts a sudden drop in blood pressure of a patient P, for example, from a change in blood flow rate in the earlobe (peripheral part) of the patient P undergoing dialysis treatment at a medical institution.

[0017] The monitoring system 100 shown in FIG. 1 includes a blood pressure decrease prediction device 1, a blood flow measurement device 4 (blood flow measurement unit), and a dialysis machine 5. The blood pressure decrease prediction device 1 and the blood flow measurement device 4 are connected to each other so as to be able to communicate with each other via, for example, short-range wireless communication. For example, Bluetooth (registered trademark) can be used as the short-range wireless communication. Patient P is undergoing dialysis treatment using dialysis machine 5. A sensor unit 41 of blood flow measuring device 4 is attached to the earlobe of patient P. Blood flow measuring device 4 transmits a numerical value (blood flow value) indicating the blood flow rate at the earlobe of patient P measured by sensor unit 41 to blood pressure decrease prediction device 1. Blood pressure decrease prediction device 1 predicts a tendency for blood pressure decrease based on changes in the received blood volume value.

[0018] [Blood Pressure Decrease Prediction Device 1] The blood pressure decrease prediction device 1 is a device that receives, for example, a blood flow value of a patient P undergoing dialysis treatment at a medical institution and predicts a blood pressure decrease of the patient P from the received blood flow value. The blood pressure decrease prediction device 1 is, for example, a personal computer (PC). As shown in FIG. 2, the blood pressure decrease prediction device 1 includes a control unit 10, a storage unit 20, a display unit 26, an input unit 27, an audio output unit 28, and a communication unit 29. The control unit 10 is a central processing unit (CPU) that controls the blood pressure decrease prediction device 1. The control unit 10 appropriately reads and executes the operating system (OS) and application programs stored in the storage unit 20, thereby cooperating with the above-mentioned hardware and executing various functions.

[0019] Before describing the control unit 10, the storage unit 20 will be described. The storage unit 20 is a storage area such as a hard disk or semiconductor memory element for storing programs, data, etc. required for the control unit 10 to execute various processes. The storage unit 20 stores a program storage unit 21 and a blood flow value storage unit 22 . The program storage unit 21 is a storage area for storing various programs, such as programs for executing various functions of the control unit 10 (described later). The programs stored in the program storage unit 21 may be separate programs for each functional unit or multiple functional units of the control unit 10, or may be a single program.

[0020] The blood flow value storage unit 22 is a storage area for storing the patient's blood flow in chronological order. The blood flow value storage unit 22 stores the blood flow value in association with, for example, the elapsed time since the first blood flow value was received. The storage unit 20 also stores other information, such as the serial number of the blood flow measuring device 4, which is set in advance in the blood pressure decrease prediction device 1.

[0021] Next, the control unit 10 will be described. The control unit 10 includes a blood flow value acquisition unit 11, a reference value acquisition unit 12, a change rate calculation unit 13, and a notification control unit 14 (notification unit). The blood flow value acquiring unit 11 functions as a blood flow value acquiring means. The blood flow value acquiring unit 11 acquires a blood flow value, which is a numerical value indicating the blood flow, from the blood flow measuring device 4. The blood flow value acquired by the blood flow value acquiring unit 11 is a numerical value of the blood flow in a peripheral part of the patient P, and specifically, for example, is the value of the blood flow in the earlobe of the patient P. The blood flow value acquiring unit 11 may constantly acquire the blood flow value from the blood flow measuring device 4. Alternatively, the blood flow value acquiring unit 11 may acquire the blood flow value from the blood flow measuring device 4 at a predetermined time interval (for example, 1 second, etc.).

[0022] The reference value acquiring unit 12 functions as a reference value acquiring means. For example, the reference value acquiring unit 12 acquires as a judgment reference value a first rate of change calculated from the blood flow value after a predetermined time from the start of dialysis among the blood flow values ​​acquired by the blood flow measuring device 4. The reference value acquiring unit 12 sets the predetermined time to, for example, 10 minutes, and sets as the judgment reference value, for example, a rate of change per second calculated using the blood flow value immediately after the start of dialysis and the blood flow value 10 minutes after the start of dialysis.

[0023] The change rate calculation unit 13 calculates a first change rate and a second change rate (change rate) of the blood flow rate from time series data of the blood flow rate based on the blood flow rate value acquired by the blood flow rate value acquisition unit 11. The change rate calculation unit 13 calculates the first change rate from the current blood flow rate value and the blood flow value 10 minutes prior according to the measurement interval. The change rate calculation unit 13 also calculates the second change rate using the calculated first change rate and the judgment reference value acquired by the reference value acquisition unit 12. The change rate calculation unit 13 may calculate the second change rate over a predetermined time interval, for example, as a moving average. Specifically, for example, when blood flow rate is acquired every second, the change rate calculation unit 13 calculates the first change rate as the change rate of the moving average of blood flow rate over 10 minutes. Then, the change rate calculation unit 13 calculates the second change rate using the calculated first change rate and the judgment reference value.

[0024] The notification control unit 14 functions as a notification means. When the second rate of change calculated by the rate of change calculation unit 13 falls below a predetermined threshold, the notification control unit 14 determines that the blood pressure is on a downward trend and issues a notification indicating this downward trend using the audio output unit 28 or the display unit 26. Here, when the measurement target is blood flow volume at the earlobe, clinical studies have shown that the threshold is approximately -2.3% to -2.4%. Furthermore, clinical studies have shown that when the second rate of change calculated by the rate of change calculation unit 13 falls below the threshold, a drop in blood pressure occurs 5 to 10 minutes after the second rate of change falls below the threshold.

[0025] The clinical research mentioned above will be explained using research examples. 3 and 4 are diagrams for explaining thresholds used in the processing of the blood pressure decrease prediction device according to the first embodiment. 3A shows a graph 30 in which the left axis represents a line graph 31 of EBF (Earlobe Blood Flow), which is the amount of earlobe blood flow from the start of dialysis for a patient, and the right axis represents a bar graph 32 of ΔaEBF, which is a second rate of change in earlobe blood flow. An example of a method for calculating ΔaEBF is described below.

[0026] The earlobe blood flow 10 minutes after the start of dialysis is defined as EBF (10 min), and the judgment reference value is defined as aEBF (10 min). EBF (10 min) is used to express the following formula 1. aEBF(10min)=(EBF(10min)-EBF(0min)) / 600 ...(Formula 1)

[0027] Furthermore, aEBF(t), which is the first rate of change when the time elapsed since the start of dialysis is t, is expressed by the following equation 2. aEBF(t)=(EBF(t)-EBF(t-10min)) / 600 ...(Formula 2) Here, aEBF(t) is the difference between the blood flow value at the reference time t and the blood flow value 10 minutes before time t, expressed as the difference over one second (first rate of change).

[0028] The second rate of change, ΔaEBF(t), when the time elapsed since the start of dialysis is t, is expressed by the following equation 3. ΔaEBF(t)=(aEBF(t) / aEBF(10min))-1 ...(Formula 3) Here, ΔaEBF(t) represents the proportion of the first rate of change at time t based on the judgment reference value.

[0029] 3A, a threshold value 33 is shown at a position where ΔaEBF is −2.4%. Time tx indicates the point in time at which ΔaEBF falls below the threshold value 33. On the other hand, Figure 3(B) is a graph 35 showing the blood pressure of the same patient from the start of dialysis. Referring to graph 35, it can be seen that a drop in blood pressure occurs 5 to 10 minutes (α hours) after the time tx shown in FIG. 3(A).

[0030] FIG. 4 is a graph showing the likelihood of ΔaEBF, which is the second rate of change of earlobe blood flow explained in FIG. 3, and shows result data when the number of subjects n is 118. FIG. 4(A) is a bar graph 71 showing sensitivity and specificity due to changes in ΔaEBF, which is the second rate of change in earlobe blood flow. Here, sensitivity, in this example, refers to the percentage of cases where a drop in blood pressure was predicted to occur due to a drop in blood flow and a drop in blood pressure actually occurred. Also, specificity, in this example, refers to the percentage of cases where a drop in blood pressure was predicted not to occur due to a lack of drop in blood flow and a drop in blood pressure actually did not occur. The sensitivity at position 71a of the result data where ΔaEBF was -2.4% was 82% of the 118 subjects, and the specificity at position 71a was 82% of the 118 subjects.

[0031] Figure 4(B) is a line graph 72 of the ROC (Receiver Operating Characteristic) curve based on the bar graph 71 in Figure 4(A). The ROC curve, with sensitivity on the vertical axis and 1-specificity on the horizontal axis, shows the relationship between sensitivity and specificity depending on the threshold (cutoff). The range of both the vertical and horizontal axes is 0 to 1. The position on the line graph 72 corresponding to position 71a on the bar graph 71 in Figure 4(A) is position 72a. Furthermore, AUC (Area Under the Curve) is the area under the ROC curve, and the closer it is to 1.0, the better the test's separation ability (sensitivity and specificity). When the number of subjects n was 118, the AUC was 0.87. In this embodiment, the occurrence of a decrease in blood pressure is predicted using a threshold value determined from the results of such clinical research.

[0032] Returning to the explanation of the blood pressure decrease prediction device 1. The display unit 26 in FIG. 2 is, for example, a display device such as a liquid crystal display. The input unit 27 is, for example, an input device such as a keyboard or a mouse. The display unit 26 and the input unit 27 may be integrated into a touch panel display. The audio output unit 28 is, for example, a speaker that outputs audio to the outside.

[0033] The communication unit 29 is an interface for performing short-range wireless communication with the blood flow measuring device 4. The communication unit 29 includes, for example, an IC (Integrated Circuit) chip and a loop antenna created in accordance with the Bluetooth (registered trademark) standard. The communication unit 29 can perform communication over a distance of approximately 10 m to 100 m. It should be noted that a computer refers to an information processing device equipped with a control unit, a storage device, etc., and the blood pressure decrease prediction device 1 is an information processing device equipped with a control unit 10, a storage unit 20, etc., and is included in the concept of a computer.

[0034] [Blood flow measuring device 4] The blood flow measuring device 4 is a device that measures blood flow and transmits the blood flow value to the blood pressure decrease prediction device 1. The blood flow measuring device 4 may be, for example, a laser Doppler blood flowmeter. A laser Doppler blood flowmeter irradiates near-infrared light to measure blood flow in capillaries flowing near the skin surface. When a laser detects a moving object, the laser measures blood flow using a phenomenon called the "Doppler effect," in which the frequency of scattered light changes in response to the moving speed. The laser Doppler blood flowmeter numerically represents the blood flow rate in the earlobe, where the laser is applied. Note that the blood flow measuring device 4 is not limited to the above-mentioned laser Doppler blood flowmeter, and may also be one that uses sound waves or other light.

[0035] The blood flow measuring device 4 includes a sensor unit 41 (blood flow measuring unit) and a communication unit 49. The sensor unit 41 is attached to, for example, the earlobe of the patient P to detect the blood flow in the earlobe. The sensor unit 41 continuously irradiates a constant amount of light and detects the amount of returning light, which changes according to the amount of blood flow in the capillaries in the area where the light is irradiated. The communication unit 49 is an interface for performing short-distance wireless communication with the blood pressure decrease prediction device 1. Although not shown, the blood flow measuring device 4 includes a control unit, a storage unit, and the like.

[0036] [Dialysis machine 5] The dialysis machine 5 shown in FIG. 1 is an apparatus comprising a blood purification circuit having an arterial blood circuit and a venous blood circuit that constitute a blood circuit for circulating at least the blood of a patient P extracorporeally, a blood purifier having a plurality of connectors connectable to the blood purification circuit for purifying the blood circulating extracorporeally in the blood circuit, and an apparatus main body (console) in which various treatment means for performing blood purification treatment using the blood circuit and the blood purifier are arranged.

[0037] [Processing Description] Next, the processing in the blood pressure decrease prediction device 1 will be described. FIG. 5 is a flowchart showing the blood pressure decrease prediction process of the blood pressure decrease prediction device 1 according to the first embodiment. As a prerequisite for performing blood pressure decrease prediction processing, first, a medical professional (for example, a person operating the blood pressure decrease prediction device 1 at a medical institution, hereinafter referred to as the operator) executes a program (not shown) for blood pressure decrease prediction processing stored in the program memory unit 21 of the blood pressure decrease prediction device 1.

[0038] The operator also attaches the sensor unit 41 of the blood flow measuring device 4 to the earlobe of the patient P about to start dialysis treatment. Here, the sensor unit 41 is attached to either the left or right earlobe of the patient P. Then, the operator operates the blood pressure decrease prediction device 1 and the blood flow measuring device 4, respectively, and in step S (hereinafter, "step S" will be simply referred to as "S") 11 of Figure 5, the control unit 10 establishes communication between the blood pressure decrease prediction device 1 and the blood flow measuring device 4.

[0039] Thereafter, the operator starts dialysis treatment of the patient P, and the control unit 10 accepts the start of measurement through an operation by the operator on the blood pressure decrease prediction device 1. For example, the control unit 10 accepts the start of measurement through the operator selecting a button (described later) for starting measurement on a monitor screen (not shown) displayed on the display unit 26. In S12, the control unit 10 (blood flow value acquisition unit 11) acquires the blood flow value from the blood flow measurement device 4. Then, the control unit 10 stores the acquired blood flow value in the blood flow value storage unit 22 in association with time. In S13, the control unit 10 (reference value acquisition unit 12) calculates the first rate of change using the blood flow rate value 10 minutes after the start of dialysis, for example, and acquires it as the judgment reference value.

[0040] In S14, the control unit 10 (change rate calculation unit 13) calculates the rate of change from the time series data of blood flow based on the blood flow values ​​acquired by the blood flow value acquisition unit 11 and stored in the blood flow value storage unit 22. Specifically, the control unit 10 (change rate calculation unit 13) calculates a first rate of change of blood flow from the time series data of blood flow, and calculates a second rate of change of blood flow from the first rate of change and the judgment reference value. In S15, the control unit 10 determines whether the calculated second rate of change (rate of change) is below a predetermined threshold. If the calculated second rate of change is below the predetermined threshold (S15: YES), the control unit 10 proceeds to S16. On the other hand, if the calculated second rate of change is not below the predetermined threshold (S15: NO), the control unit 10 proceeds to S17.

[0041] In S16, the control unit 10 (notification control unit 14) determines that the blood pressure is on a downward trend and issues a notification indicating this downward trend using the audio output unit 28 or the display unit 26. The control unit 10 may issue the notification by, for example, outputting a warning sound from the audio output unit 28. Alternatively, the control unit 10 may issue the notification by outputting a warning screen such as "Your blood pressure is on a downward trend" to the display unit 26. Thereafter, the control unit 10 ends this process.

[0042] On the other hand, in S17, the control unit 10 determines whether or not to terminate this process, for example, based on an input by the operator via the input unit 27. The operator inputs an indication of termination, for example, when dialysis is to be terminated or when dialysis is to be stopped midway. If this process is to be terminated (S17: YES), the control unit 10 terminates this process. On the other hand, if this process is not to be terminated (S17: NO), the control unit 10 proceeds to S18. In S18, the control unit 10 (blood flow value acquisition unit 11) acquires the blood flow value from the blood flow measurement device 4. Thereafter, the control unit 10 moves the process to S14.

[0043] When the blood pressure decrease prediction device 1 issues a notification indicating a blood pressure decrease tendency, the operator takes measures to improve the peripheral condition of the patient P, for example, by operating the dialysis device 5 to stop water removal, slow down the water removal speed, or administer fluid replacement. The operator also takes measures, for example, to elevate the lower limbs of the patient P. These measures are intended to stabilize the blood pressure.

[0044] As described above, the monitoring system 100 according to the first embodiment provides the following effects. (1) The blood pressure decrease prediction device 1 includes a blood flow value acquisition unit 11 that acquires a blood flow value, which is a value of the blood flow, from a blood flow measurement device 4 that continuously measures the blood flow in the peripheral area of ​​a patient P undergoing dialysis; a change rate calculation unit 13 that calculates the rate of change of the blood flow from time series data of the blood flow based on the blood flow value acquired by the blood flow value acquisition unit 11; and an alarm control unit 14 that issues an alarm indicating a tendency for blood pressure to decrease when the change rate calculated by the change rate calculation unit 13 falls below a predetermined threshold. This makes it possible to use the results of measuring the blood flow rate in the peripheral region of patient P to predict in advance whether a drop in blood pressure will occur during dialysis, and to issue a notification indicating a drop in blood pressure.

[0045] (2) The blood pressure decrease prediction device 1 is provided with a reference value acquisition unit 12 that acquires a judgment reference value based on the blood flow value acquired by the blood flow value acquisition unit 11 after a predetermined time has elapsed since the start of dialysis, and the change rate calculation unit 13 calculates the change rate using the judgment reference value acquired by the reference value acquisition unit 12. This allows the rate of change to be calculated using the stable blood flow value after the start of dialysis.

[0046] (3) The change rate calculation unit 13 calculates the change rate over a predetermined time interval as a moving average. This makes it possible to smooth the data used to calculate the rate of change, making it easier to grasp the trend in the rate of change.

[0047] (4) The blood flow value acquiring unit 11 acquires the blood flow value at the patient P's earlobe. This allows blood flow to be obtained at the earlobe, where changes in blood flow in the head are particularly likely to occur, making it easier to more accurately grasp trends in blood pressure decline.

[0048] (Second embodiment) Next, a second embodiment of the present invention will be described. In the second embodiment, a blood pressure decrease prediction device and a dialysis device are enabled to communicate with each other, and the blood pressure decrease prediction device controls the dialysis device. In the following description, parts that perform the same functions as those in the first embodiment are designated by the same reference numerals or with the same reference numerals at the end, and duplicated descriptions will be omitted as appropriate.

[0049] [Monitoring System 200] FIG. 6 is a diagram showing functional blocks of each device used in a monitoring system 200 according to the second embodiment. The monitoring system 200 shown in FIG. 6 includes a blood pressure decrease prediction device 201, a blood flow measurement device 4, and a dialysis device 205. The blood pressure decrease prediction device 201 and the blood flow measuring device 4, and the blood pressure decrease prediction device 201 and the dialysis device 205 are each communicably connected via, for example, short-range wireless communication.

[0050] [Blood Pressure Decrease Prediction Device 201] The blood pressure decrease prediction device 201 includes a control unit 210 , a storage unit 220 , a display unit 26 , an input unit 27 , an audio output unit 28 , and a communication unit 229 . The control unit 210 includes a blood flow value acquisition unit 11 , a reference value acquisition unit 12 , a change rate calculation unit 13 , a notification control unit 14 , and a control signal transmission unit 215 . The control signal transmitting unit 215 transmits a control signal to the dialysis device 205 based on the rate of change calculated by the rate of change calculating unit 13. More specifically, when the rate of change calculated by the rate of change calculating unit 13 is below a predetermined threshold, the control signal transmitting unit 215 transmits, for example, a control signal related to water removal to the dialysis device 205.

[0051] The storage unit 220 stores a program storage unit 221 and a blood flow value storage unit 22. The program storage unit 221 is a storage area for storing various programs, such as programs for executing the various functions of the control unit 210 described above. The communication unit 229 is an interface for performing short-range wireless communication with the blood flow measuring device 4 and with the dialysis machine 205 .

[0052] [Dialysis machine 205] In the following, we will omit a description of the functions for dialysis such as the blood purification circuit, blood purifier, and various treatment means that the dialysis device 205 has, and will explain the various functions necessary for explaining this embodiment.

[0053] The dialysis machine 205 includes a control unit 250, a storage unit 251, a display unit 256, an operation unit 257, and a communication unit 259. The control unit 250 is a CPU that controls the entire dialysis device 205. The control unit 250 appropriately reads and executes the OS and application programs stored in the storage unit 251, thereby cooperating with the above-mentioned hardware and performing various functions. The control unit 250 includes a water removal control unit (not shown) that controls water removal in accordance with a control signal received from the blood pressure decrease prediction device 201.

[0054] The storage unit 251 is a storage area such as a hard disk or semiconductor memory element for storing programs, data, etc. required for the control unit 250 to execute various processes. The display unit 256 is, for example, a display device such as an LCD (Liquid Crystal Display). The operation unit 257 is, for example, an input device such as an operation button or a pointing device such as a controller. The communication unit 259 is an interface for performing short-distance wireless communication with the blood pressure decrease prediction device 1.

[0055] [Processing Description] Next, the processing in the blood pressure decrease prediction device 201 will be described. FIG. 7 is a flowchart showing the blood pressure decrease prediction process of the blood pressure decrease prediction device 201 according to the second embodiment. As a prerequisite for performing the blood pressure decrease prediction process, first, the operator executes a program (not shown) for the blood pressure decrease prediction process stored in the program storage unit 221 of the blood pressure decrease prediction device 201. The operator also attaches the sensor unit 41 of the blood flow measuring device 4 to the earlobe of the patient P about to start dialysis treatment. Here, the sensor unit 41 is attached to either the left or right earlobe of the patient P. Furthermore, the operator operates the dialysis device 205 to bring the dialysis treatment for the patient P into a state in which it can begin.

[0056] Then, the operator operates the blood pressure decrease prediction device 201, the blood flow measuring device 4, and the dialysis device 205, respectively, to establish communication between the blood pressure decrease prediction device 201 and the dialysis device 205 and between the blood pressure decrease prediction device 201 and the blood flow measuring device 4 in S211 of Figure 7. Thereafter, the operator operates the dialysis device 205 to start dialysis treatment for the patient P. The processing from S212 to S216 in FIG. 7 is the same as the processing from S12 to S16 in the first embodiment (FIG. 5).

[0057] In S217, the control unit 210 (control signal transmission unit 215) transmits a control signal to the dialysis machine 205. When the dialysis device 205 receives the control signal from the blood pressure decrease prediction device 201, the control unit 250 (water removal control unit) performs processing to control water removal in accordance with the control signal. S218 and S219 in FIG. 7 are similar to the processes of S17 and S18 in the first embodiment (FIG. 5).

[0058] As described above, the monitoring system 200 according to the second embodiment provides the following effects. The blood pressure decrease prediction device 201 is provided with a control signal transmitting unit 215 that transmits a control signal to a dialysis device 205 that is communicatively connected to the blood pressure decrease prediction device 201 based on the rate of change calculated by the rate of change calculating unit 13, and the dialysis device 205 controls water removal in accordance with the received control signal. This makes it possible to use the results of measuring the blood flow rate in the peripheral areas of patient P to predict in advance whether a drop in blood pressure will occur during dialysis, and to automatically control the dialysis device 205 to take preventive measures to prevent a drop in blood pressure.

[0059] The present invention is not limited to the embodiments, and includes modifications and improvements within the scope of achieving the object of the present invention. The above-described embodiments and the modifications described below can be used in combination as appropriate, but detailed description thereof will be omitted.

[0060] (Variations) (1) In each embodiment, the blood flow measuring device is attached to the patient's earlobe, but this is not limiting. The blood flow measuring device may be attached to any other part of the patient's periphery. The correlation between cerebral blood flow and mean blood pressure has been reported in the following paper. Lassen, Niels A. “Cerebral blood flow and oxygen consumption in man.” Physiological reviews 39.2(1959):183-238. Therefore, it is believed that measuring blood flow at peripheral sites such as the earlobe is an effective indicator of blood pressure reduction, and it is also believed that it can be used in the same way at the patient's forehead, for example.

[0061] (2) In each embodiment, an example has been described in which a notification indicating a blood pressure decrease trend is issued when the rate of change falls below a predetermined threshold. However, this is not limited to this. For example, a notification indicating a blood pressure decrease trend may be issued using a learning model based on machine learning. Specifically, for example, a learning model that is trained by associating time series data of a patient's blood flow value with time series data of their blood pressure status is used. The control unit (sign prediction unit) of the blood pressure decrease prediction device inputs time series data of blood flow based on the blood flow value acquired by the blood flow value acquisition unit 11 into the learning model. Then, the control unit (notification unit) of the blood pressure decrease prediction device issues a notification indicating a blood pressure decrease trend according to the blood pressure state prediction output from the learning model.

[0062] Alternatively, for example, a learning model may be used that is learned by associating the rate of change with the blood pressure state of the patient at the time when the rate of change is indicated. The control unit (sign prediction unit) of the blood pressure decrease prediction device inputs to the learning model the rate of change calculated from the time-series data of blood flow based on the blood flow value acquired by the blood flow value acquisition unit 11. Then, the control unit (notification unit) of the blood pressure decrease prediction device issues a notification indicating a blood pressure decrease trend according to the prediction of the blood pressure state output from the learning model. In this way, even when a learning model is used, it is possible to predict in advance the occurrence of a drop in blood pressure during dialysis from time series data of blood flow.

[0063] (3) In each embodiment, the blood pressure decrease prediction device is described as being implemented by a general computer, but this is not limiting. The function of the blood pressure decrease prediction device may be incorporated into, for example, a dialysis machine. This would make it easier to control water removal and other processes in the dialysis machine.

[0064] (4) In each embodiment, the devices are connected to each other so that they can communicate with each other via short-range wireless communication, and communication via Bluetooth (registered trademark) is described as an example, but this is not limiting. For example, other wireless communication such as Wi-Fi may be used, or other devices may be connected to each other via a wired connection for communication. [Explanation of symbols]

[0065] 1, 201 Blood pressure drop prediction device 4 Blood flow measurement equipment 10, 210, 250 control section 11 Blood flow value acquisition unit 12 Reference value acquisition section 13 Change rate calculation section 14 Notification control section 20, 220, 251 storage section 21, 221 Program memory section 22 Blood flow value storage unit 26, 256 display section 27 Input section 28 Audio output section 29, 49, 229, 259 Communications Department 41 Sensor unit 100, 200 Monitoring System 215 Control signal transmitter P patient

Claims

1. a blood flow value acquiring unit that acquires a blood flow value, which is a value of the blood flow, from a blood flow measuring unit that continuously measures the blood flow in a peripheral part of a patient undergoing dialysis; a change rate calculation unit that calculates a change rate of the blood flow rate from time series data of the blood flow rate based on the blood flow rate value acquired by the blood flow rate value acquisition unit; a notification unit that notifies a blood pressure decrease tendency based on the rate of change calculated by the rate of change calculation unit; A blood pressure decrease prediction device comprising:

2. 2. The blood pressure decrease prediction device according to claim 1, The notification unit issues a notification indicating a tendency for blood pressure to decrease when the rate of change calculated by the rate of change calculation unit falls below a predetermined threshold.

3. 3. The blood pressure decrease prediction device according to claim 2, a reference value acquiring unit that acquires a judgment reference value based on the blood flow value acquired by the blood flow value acquiring unit after a predetermined time from the start of dialysis, The change rate calculation unit calculates the change rate using the determination reference value acquired by the reference value acquisition unit.

4. 3. The blood pressure decrease prediction device according to claim 2, The change rate calculation unit calculates the change rate over a predetermined time interval using a moving average.

5. 3. The blood pressure decrease prediction device according to claim 2, The blood pressure decrease prediction device, wherein the blood flow value acquisition unit acquires the blood flow value at the patient's earlobe.

6. a blood flow value acquiring unit that acquires a blood flow value, which is a value of the blood flow, from a blood flow measuring unit that continuously measures the blood flow in a peripheral part of a patient undergoing dialysis; a sign prediction unit that inputs time-series data of the blood flow based on the blood flow value acquired by the blood flow value acquisition unit into a learning model and predicts a sign of a tendency of blood pressure decreasing; a notification unit that notifies a blood pressure decrease tendency in accordance with the prediction by the sign prediction unit; Equipped with The learning model is learned by associating the time series data of the patient's blood flow value with the time series data of the patient's blood pressure state.

7. The blood pressure decrease prediction device according to any one of claims 1 to 6, a dialysis machine communicably connected to the blood pressure decrease prediction device; A monitoring system comprising: the blood pressure decrease prediction device includes a control signal transmission unit that transmits a control signal to the dialysis machine based on the rate of change calculated by the rate of change calculation unit or the prediction by the sign prediction unit; The dialysis device is equipped with a water removal control unit that controls water removal in accordance with the received control signal.

8. The computers that make up the monitoring system are a blood flow value acquiring means for acquiring a blood flow value from a blood flow measuring device that continuously measures the blood flow rate at a peripheral site of a patient undergoing dialysis; a change rate calculation means for calculating a change rate of the blood flow rate from time series data of the blood flow rate based on the blood flow rate value acquired by the blood flow rate value acquisition means; a notification means for notifying the user of a blood pressure decrease tendency when the change rate calculated by the change rate calculation means is lower than a predetermined threshold value; A program to make it function as such.

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