Blood pressure estimation device, blood pressure estimation method, and blood pressure estimation program

Abstract

To provide a blood pressure estimation device, a blood pressure estimation method, and a blood pressure estimation program capable of estimating an estimated value of blood pressure with high accuracy.SOLUTION: A blood pressure estimation device includes a calculation unit that calculates a calculation value of a first blood pressure and a calculation value of a pulse rate from biological information, and an estimation unit that estimates an estimation value of a second blood pressure different from the first blood pressure from the calculation value of the first blood pressure and the calculation value of the pulse rate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to a blood pressure estimation device, a blood pressure estimation method, and a blood pressure estimation program. This application claims priority under Japanese Patent Application No. 2024-103460, filed in Japan on June 27, 2024, the contents of which are incorporated herein by reference. [Background technology]

[0002] Patent Document 1 discloses a blood pressure estimation device. In this blood pressure estimation device, heart rate and corrected normalized pulse wave volume are obtained by photoplethysmography, and blood pressure is calculated from the obtained heart rate and corrected normalized pulse wave volume. The calculated blood pressure includes systolic blood pressure and diastolic blood pressure (paragraphs 0022, 0030 and 0031). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-49134 [Overview of the project] [Problems that the invention aims to solve]

[0004] In the blood pressure estimation device disclosed in Patent Document 1, the calculated value of either systolic blood pressure or diastolic blood pressure may have high accuracy, while the calculated value of the other systolic or diastolic blood pressure may have low accuracy.

[0005] One aspect of this disclosure has been made in view of this problem. One aspect of this disclosure aims to provide, for example, a blood pressure estimation device, a blood pressure estimation method, and a blood pressure estimation program that can estimate blood pressure with high accuracy. [Means for solving the problem]

[0006] A blood pressure estimation device according to a first aspect of this disclosure includes a calculation unit that calculates a first blood pressure value and a pulse rate value from biological information, and an estimation unit that estimates a second blood pressure value different from the first blood pressure value from the first blood pressure value and the pulse rate value.

[0007] A blood pressure estimation method according to a second aspect of the present disclosure includes calculating a first blood pressure value and a pulse rate value from biological information, and estimating a second blood pressure value different from the first blood pressure value from the first blood pressure value and the pulse rate value.

[0008] A blood pressure estimation program according to a third aspect of this disclosure causes a computer to perform the following actions: calculate a first blood pressure value and a pulse rate value from biological information, and estimate a second blood pressure value different from the first blood pressure value from the first blood pressure value and the pulse rate value.

[0009] A blood pressure estimation method according to a fourth aspect of the present disclosure includes: acquiring a plurality of measurement groups by a blood pressure monitor, each measurement group including a first blood pressure measurement, a pulse rate measurement, and a second blood pressure measurement different from the first blood pressure; creating a function of the first blood pressure and the pulse rate from the plurality of measurement groups; calculating the first blood pressure value and the pulse rate value from the biological information; and estimating the second blood pressure estimate from the value of the function obtained by substituting the first blood pressure value and the pulse rate value into the function.

[0010] A blood pressure estimation device according to a fifth aspect of the present disclosure comprises a calculation unit that calculates a first blood pressure value and a period value from biological information, and an estimation unit that estimates a second blood pressure value different from the first blood pressure value from the first blood pressure value and the period value.

[0011] A blood pressure estimation method according to a sixth aspect of this disclosure includes calculating a first blood pressure value and a period value from biological information, and estimating a second blood pressure value different from the first blood pressure value from the first blood pressure value and the period value.

[0012] The blood pressure estimation program according to the seventh aspect of the present disclosure causes a computer to calculate a calculated value of a first blood pressure and a calculated value of a cycle from biological information, and estimate an estimated value of a second blood pressure different from the first blood pressure from the calculated value of the first blood pressure and the calculated value of the cycle.

[0013] The blood pressure estimation method according to the eighth aspect of the present disclosure includes obtaining, with a sphygmomanometer, a plurality of measurement value groups in which each measurement value group includes a measurement value of a first blood pressure, a measurement value of a cycle, and a measurement value of a second blood pressure different from the first blood pressure; creating a function of the first blood pressure and the cycle from the plurality of measurement value groups; calculating a calculated value of the first blood pressure and a calculated value of the cycle from biological information; and estimating an estimated value of the second blood pressure from a value of the function when the calculated value of the first blood pressure and the calculated value of the cycle are substituted into the function.

Brief Description of Drawings

[0014] [Figure 1] It is a block diagram of the blood pressure estimation device according to the first embodiment. [Figure 2] It is a block diagram of a computer provided in the blood pressure estimation device according to the first embodiment. [Figure 3] It is an example of a Bland-Altman plot of the calculated value of the minimum blood pressure calculated by an existing method. [Figure 4] It is an example of a Bland-Altman plot of the estimated value of the minimum blood pressure estimated by the blood pressure estimation device according to the first embodiment. [Figure 5] It is a flowchart showing the flow of processing performed by the blood pressure estimation device according to the first embodiment. [Figure 6] It is a flowchart showing the flow of processing for creating a function used by the estimation unit provided in the blood pressure estimation devices according to the first, second, and third embodiments. [Figure 7] It is a block diagram of the blood pressure estimation device according to the second embodiment. [Figure 8] It is a flowchart showing the flow of processing performed by the blood pressure estimation device according to the second embodiment. [Figure 9] This is a block diagram of the blood pressure estimation device according to the third embodiment. [Figure 10] This figure shows the information processed by the blood pressure estimation device of the third embodiment. [Figure 11] This is a flowchart showing the processing flow performed by the blood pressure estimation device of the third embodiment. [Modes for carrying out the invention]

[0015] The embodiments of this disclosure will be described below with reference to the drawings. In the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant descriptions are omitted.

[0016] 1. First Embodiment 1.1 Blood pressure estimation device Figure 1 is a block diagram of the blood pressure estimation device according to the first embodiment.

[0017] The blood pressure estimation device 1 of the first embodiment shown in Figure 1 acquires the pulse wave 101 of a living organism, calculates the systolic blood pressure value 102 and the pulse rate value 104 from the acquired pulse wave 101, and estimates the diastolic blood pressure value 106 from the calculated systolic blood pressure value 102 and pulse rate value 104. The systolic blood pressure is the blood pressure when the living organism's heart is contracting most strongly, and is also called systolic blood pressure or maximum blood pressure. The diastolic blood pressure is the blood pressure when the living organism's heart is expanding most strongly, and is also called diastolic blood pressure or minimum blood pressure. In the blood pressure estimation device 1, the systolic blood pressure is a first blood pressure for which a highly accurate calculation value can be calculated, and the diastolic blood pressure is a second blood pressure that differs from the first blood pressure and for which a highly accurate calculation value cannot be calculated.

[0018] As shown in Figure 1, the blood pressure estimation device 1 comprises an acquisition unit 11, a calculation unit 12, and an estimation unit 13.

[0019] The acquisition unit 11 acquires the pulse wave 101 of the living body and passes the acquired pulse wave 101 to the calculation unit 12. Alternatively, a pulse wave 101 acquired by a device other than the blood pressure estimation device 1 may be input to the blood pressure estimation device 1, and the input pulse wave 101 may be passed to the calculation unit 12.

[0020] The acquisition unit 11 is equipped with a pulse wave sensor. Pulse wave sensors include contact-type pulse wave sensors and non-contact-type pulse wave sensors. Contact-type pulse wave sensors acquire the pulse wave 101 of a living body when in contact with the living body. Examples of contact-type pulse wave sensors include reflective-type photoelectric pulse wave sensors, transmissive-type photoelectric pulse wave sensors, piezoelectric sensors, etc. Non-contact-type pulse wave sensors acquire the pulse wave 101 of a living body when not in contact with the living body. Examples of non-contact-type pulse wave sensors include pulse wave sensors equipped with microwave Doppler sensors, sensors that acquire pulse waves using photoplethysmography from images of living bodies, etc.

[0021] The calculation unit 12 calculates the calculated value of systolic blood pressure 102 and the calculated value of pulse rate 104 from the pulse wave 101 that it receives, and passes the calculated value of systolic blood pressure 102 and the calculated value of pulse rate 104 to the estimation unit 13. The calculation unit 12 calculates the calculated value of systolic blood pressure 102 from information such as the amplitude, wavelength, waveform characteristics, and frequency spectrum of the pulse wave 101, and calculates the calculated value of pulse rate 104 from information such as the period, frequency spectrum, spectrogram, and number of peaks of the pulse wave 101. For example, the calculated value of pulse rate 104 may be calculated by taking the reciprocal of the period of the pulse wave 101.

[0022] The calculation unit 12 can calculate a highly accurate systolic blood pressure value 102, but it cannot calculate a highly accurate diastolic blood pressure value. Furthermore, the calculation unit 12 can calculate a highly accurate pulse rate value 104.

[0023] The acquisition unit 11 may acquire biological information other than the pulse wave 101, and the calculation unit 12 may calculate the calculated value of the systolic blood pressure 102 and the calculated value of the pulse rate 104 from the acquired biological information other than the pulse wave 101. The biological information other than the pulse wave 101 may be the time change of an image of the body, the time change of the body's complexion, etc.

[0024] The estimation unit 13 estimates the diastolic blood pressure 106 from the calculated systolic blood pressure 102 and calculated pulse rate 104 that it has been given, and outputs the estimated diastolic blood pressure 106. The estimation unit 13 uses an estimation formula that has been prepared in advance for estimating the diastolic blood pressure 106 from the calculated systolic blood pressure 102 and calculated pulse rate 104. The estimation formula used is a function 111 of systolic blood pressure and pulse rate. The estimation unit 13 estimates the diastolic blood pressure 106 from the value of the function 111 obtained by substituting the calculated systolic blood pressure 102 and calculated pulse rate 104 into the function 111. For example, the estimation unit 13 uses the value of the function 111 obtained by substituting the calculated systolic blood pressure 102 and calculated pulse rate 104 into the function 111 as the estimated diastolic blood pressure 106.

[0025] Generally, the calculated pulse rate 104 has high accuracy. Therefore, if the calculation unit 12 can calculate a highly accurate systolic blood pressure 102, and the function 111 expresses the relationship between systolic blood pressure, pulse rate, and diastolic blood pressure with high accuracy, even if the calculation unit 12 cannot calculate a highly accurate diastolic blood pressure 102, the calculation pulse rate 104, and the function 111, the estimation unit 13 can estimate a highly accurate diastolic blood pressure 106 from the calculated systolic blood pressure 102, the calculated pulse rate 104, and the function 111.

[0026] The blood pressure estimation device 1 may include a display unit that displays the estimated minimum blood pressure value 106, a communication unit that transmits the estimated minimum blood pressure value 106 to an external source, a storage unit that stores the estimated minimum blood pressure value 106, and the like.

[0027] 1.2 Functions used to estimate diastolic blood pressure Function 111 preferably uses the factor SYS, where systolic blood pressure is SYS and pulse rate is HR. γ_1 × parts γ_2 Includes. Factor SYS γ_1 × parts γ_2The coefficients γ_1 and γ_2 included in it can be determined by performing multiple regression analysis using a plurality of measurement value groups obtained by a sphygmomanometer, where each measurement value group includes a measurement value of systolic blood pressure, a measurement value of pulse rate, and a measurement value of diastolic blood pressure. The sphygmomanometer only needs to be able to obtain measurement values of systolic blood pressure, pulse rate, and diastolic blood pressure with high accuracy. For example, it can be a general upper arm cuff type sphygmomanometer. When function 111 includes factor SYS γ_1 ×HR γ_2 and the coefficients γ_1 and γ_2 are determined by performing multiple regression analysis, function 111 represents the relationship between systolic blood pressure, pulse rate, and diastolic blood pressure with high accuracy.

[0028] More preferably, when systolic blood pressure is SYS, pulse rate is HR, and diastolic blood pressure is DIA, function 111 is represented by formula (1). The coefficients α_0, α_1, α_2, α_3, α_4, γ_1, and γ_2 included in formula (1) can be determined by performing multiple regression analysis using a plurality of measurement value groups obtained by a sphygmomanometer, where each measurement value group includes a measurement value of systolic blood pressure, a measurement value of pulse rate, and a measurement value of diastolic blood pressure. The sphygmomanometer only needs to be able to obtain measurement values of systolic blood pressure, pulse rate, and diastolic blood pressure with high accuracy. For example, it can be a general upper arm cuff type sphygmomanometer.

[0029]

Equation

[0030] 1.3 Estimation of blood pressure values ​​other than diastolic blood pressure The estimation unit 13 may also estimate blood pressure values ​​other than the diastolic blood pressure. These other blood pressure values ​​include pulse pressure and mean arterial pressure. Pulse pressure is the blood pressure obtained by subtracting the diastolic blood pressure from the systolic blood pressure. Mean arterial pressure is the blood pressure obtained by adding 1 / 3 of the pulse pressure to the diastolic blood pressure.

[0031] When estimating pulse pressure, the estimation unit 13 estimates the pulse pressure from the value of a function obtained by substituting the calculated value of systolic blood pressure 102 and the calculated value of pulse rate 104 into a function of systolic blood pressure and pulse rate, similar to when estimating diastolic blood pressure 106. Preferably, the function is such that systolic blood pressure is SYS and pulse rate is HR, and the factor SYS γ_1 × parts γ_2 The factor SYS is expressed by equation (2), where systolic blood pressure is SYS, pulse rate is HR, and pulse pressure is PP. γ_1 × parts γ_2 The coefficients γ_1 and γ_2 included in equation (2), and the coefficients α_0, α_1, α_2, α_3, α_4, γ_1, and γ_2 included in equation (2), can be determined by performing multiple regression analysis using multiple measurement sets obtained by a blood pressure monitor, each set of measurements including systolic blood pressure, pulse rate, and pulse pressure. The blood pressure monitor only needs to be able to obtain highly accurate systolic blood pressure, pulse rate, and pulse pressure measurements, for example, a general upper arm cuff type blood pressure monitor.

[0032]

number

[0033] The estimation unit 13, when estimating the mean blood pressure, estimates the mean blood pressure from the value of a function obtained by substituting the calculated value of systolic blood pressure 102 and the calculated value of pulse rate 104 into a function of systolic blood pressure and pulse rate, similar to when estimating the diastolic blood pressure estimate 106. Preferably, the function is such that systolic blood pressure is SYS and pulse rate is HR, and the factor SYS γ_1 × parts γ_2 The factor SYS is expressed by equation (3), which includes, and more preferably, when systolic blood pressure is denoted as SYS, pulse rate as HR, and mean arterial pressure as MAP. γ_1 × parts γ_2 The coefficients γ_1 and γ_2 included in equation (3), and the coefficients α_0, α_1, α_2, α_3, α_4, γ_1, and γ_2 included in equation (3), can be determined by performing multiple regression analysis using multiple measurement sets obtained by a blood pressure monitor, each set of measurements including systolic blood pressure, pulse rate, and mean arterial pressure. The blood pressure monitor only needs to be able to obtain highly accurate systolic blood pressure, pulse rate, and mean arterial pressure measurements, for example, a general upper arm cuff type blood pressure monitor.

[0034]

number

[0035] 1.4 Execution of a computer-based blood pressure estimation program Figure 2 is a block diagram of the computer included in the blood pressure estimation device of the first embodiment.

[0036] As shown in Figure 2, the blood pressure estimation device 1 includes a computer 21. The computer 21 includes a processor 31, memory 32, and storage 33. A blood pressure estimation program 41 is installed in the storage 33.

[0037] The processor 31 is a central processing unit (CPU), graphics processing unit (GPU), etc. The memory 32 is a random access memory (RAM), read-only memory (ROM), etc. The storage 33 is a solid-state drive (SSD), hard disk drive (HDD), etc. The processor 31 executes the blood pressure estimation program 41 loaded from the storage 33 into the memory 32 and makes the computer 21 operate as an element of the blood pressure estimation device 1. For example, the processor 31 executes the blood pressure estimation program 41 and makes the computer 21 operate as a calculation unit 12 and an estimation unit 13. The memory 32 and the storage 33 are non-temporary storage media that store the blood pressure estimation program 41.

[0038] 1.5 Comparison of the accuracy of diastolic blood pressure calculated using existing methods and the accuracy of diastolic blood pressure estimated by the blood pressure estimation device of the first embodiment. Figure 3 shows an example of a Brand-Altman plot of the diastolic blood pressure calculated using an existing method. Figure 4 shows an example of a Brand-Altman plot of the estimated diastolic blood pressure estimated by the blood pressure estimation device of the first embodiment.

[0039] In the example of the Brand-Altman plot in Figure 3, the calculated diastolic blood pressure and the average diastolic blood pressure obtained by the blood pressure monitor are plotted on the horizontal axis, and the difference between the calculated diastolic blood pressure and the measured diastolic blood pressure obtained by the blood pressure monitor is plotted on the vertical axis. In the example of the Brand-Altman plot in Figure 4, the estimated diastolic blood pressure and the average diastolic blood pressure obtained by the blood pressure monitor are plotted on the horizontal axis, and the difference between the estimated diastolic blood pressure and the measured diastolic blood pressure obtained by the blood pressure monitor is plotted on the vertical axis.

[0040] In the example of the Brand-Altman plot in Figure 3, the magnitude of the error range, expressed as ±1.96 × standard deviation (SD), is 47.5. In contrast, in the example of the Brand-Altman plot in Figure 4, the magnitude of the error range, expressed as ±1.96 × standard deviation (SD), is 25.4. This means that the estimated diastolic blood pressure value estimated by the blood pressure estimation device 1 has higher accuracy than the calculated diastolic blood pressure value obtained by existing methods.

[0041] 1.6 Flowchart of the blood pressure estimation device Figure 5 is a flowchart showing the processing flow performed by the blood pressure estimation device of the first embodiment.

[0042] The blood pressure estimation device 1 performs steps S101 to S103 shown in Figure 5.

[0043] In step S101, the acquisition unit 11 acquires the pulse wave 101.

[0044] In the subsequent step S102, the calculation unit 12 calculates the systolic blood pressure value 102 and the pulse rate value 104 from the acquired pulse wave 101.

[0045] In the subsequent step S103, the estimation unit 13 estimates the diastolic blood pressure 106 from the calculated systolic blood pressure 102 and pulse rate 104.

[0046] 1.7 Process for creating the function used by the estimation unit Figure 6 is a flowchart showing the process flow for creating a function used by the estimation unit provided in the blood pressure estimation device of the first embodiment.

[0047] When function 111 is created, steps S111 and S112 shown in Figure 6 are executed.

[0048] In step S111, multiple measurement groups are acquired by the blood pressure monitor. Each measurement group includes a systolic blood pressure measurement, a pulse rate measurement, and a diastolic blood pressure measurement. The blood pressure monitor only needs to be able to acquire highly accurate systolic blood pressure, pulse rate, and diastolic blood pressure measurements, for example, a general upper arm cuff blood pressure monitor.

[0049] In the subsequent step S112, a function 111 is created from the multiple sets of measurements obtained. At this time, the coefficients included in the function 111 are determined by performing multiple regression analysis using the set of measurements.

[0050] 2. Second Embodiment The following describes the differences between the second embodiment and the first embodiment. For aspects not described, the same configuration as that used in the first embodiment is used in the second embodiment.

[0051] Figure 7 is a block diagram of the blood pressure estimation device according to the second embodiment.

[0052] The blood pressure estimation device 2 of the second embodiment shown in Figure 7 acquires the pulse wave 101 of a living body, calculates the diastolic blood pressure value 103 and the pulse rate value 104 from the acquired pulse wave 101, and estimates the systolic blood pressure value 105 from the calculated diastolic blood pressure value 103 and pulse rate value 104. In the blood pressure estimation device 2, the diastolic blood pressure is a first blood pressure for which a highly accurate calculation value can be calculated, and the systolic blood pressure is a second blood pressure that differs from the first blood pressure and for which a highly accurate calculation value cannot be calculated.

[0053] The calculation unit 12 calculates the diastolic blood pressure value 103 and the pulse rate value 104 from the pulse wave 101 it receives, and passes the calculated diastolic blood pressure value 103 and pulse rate value 104 to the estimation unit 13. The calculation unit 12 calculates the diastolic blood pressure value 103 from information such as the amplitude, wavelength, waveform characteristics, and frequency spectrum of the pulse wave 101, and calculates the pulse rate value 104 from information such as the period, frequency spectrum, spectrogram, and number of peaks of the pulse wave 101. For example, the pulse rate value 104 may be calculated by taking the reciprocal of the period of the pulse wave 101.

[0054] The calculation unit 12 can calculate a highly accurate minimum blood pressure value 103, but it cannot calculate a highly accurate maximum blood pressure value. Furthermore, the calculation unit 12 can calculate a highly accurate pulse rate value 104.

[0055] The estimation unit 13 estimates the systolic blood pressure 105 from the calculated diastolic blood pressure 103 and calculated pulse rate 104 that it has been given, and outputs the estimated systolic blood pressure 105. The estimation unit 13 uses an estimation formula that has been prepared in advance for estimating the systolic blood pressure 105 from the calculated diastolic blood pressure 103 and calculated pulse rate 104. The estimation formula used is a function 112 for diastolic blood pressure and pulse rate. The estimation unit 13 estimates the systolic blood pressure 105 from the value of the function 112 obtained by substituting the calculated diastolic blood pressure 103 and calculated pulse rate 104 into the function 112. For example, the estimation unit 13 uses the value of the function 112 obtained by substituting the calculated diastolic blood pressure 103 and calculated pulse rate 104 into the function 112 as the estimated systolic blood pressure 105.

[0056] Generally, the calculated pulse rate 104 has high accuracy. Therefore, if the calculation unit 12 can calculate a highly accurate diastolic blood pressure 103, and the function 112 expresses the relationship between diastolic blood pressure, pulse rate, and systolic blood pressure with high accuracy, even if the calculation unit 12 cannot calculate a highly accurate systolic blood pressure 103, the estimation unit 13 can estimate a highly accurate systolic blood pressure 105 from the calculated diastolic blood pressure 103, the calculated pulse rate 104, and the function 112.

[0057] Function 112 preferably uses DIA as the minimum blood pressure and HR as the pulse rate, and the factor DIA γ_1 × parts γ_2 Includes the factor DIA. γ_1 × parts γ_2 The coefficients γ_1 and Rγ_2 included in can be determined by performing multiple regression analysis using multiple measurement sets obtained by a blood pressure monitor, each set of measurements including diastolic blood pressure, pulse rate, and systolic blood pressure. The blood pressure monitor should be capable of obtaining highly accurate diastolic blood pressure, pulse rate, and systolic blood pressure measurements; for example, a general upper arm cuff blood pressure monitor is used. Function 112 is factor DIA γ_1 × parts γ_2 If the coefficients γ_1 and γ_2 are determined by performing multiple regression analysis, function 112 will represent the relationship between diastolic blood pressure, pulse rate, and systolic blood pressure with high accuracy.

[0058] Function 112 is more preferably expressed by equation (4) when diastolic blood pressure is DIA, pulse rate is HR, and systolic blood pressure is SYS. The coefficients α_0, α_1, α_2, α_3, α_4, γ_1, and γ_2 included in equation (4) can be determined by performing multiple regression analysis using multiple measurement groups obtained by a blood pressure monitor, each of which includes diastolic blood pressure measurements, pulse rate measurements, and systolic blood pressure measurements. The blood pressure monitor should be capable of obtaining highly accurate diastolic blood pressure measurements, pulse rate measurements, and systolic blood pressure measurements, for example, a general upper arm cuff blood pressure monitor.

[0059]

number

[0060] Figure 8 is a flowchart showing the processing flow performed by the blood pressure estimation device of the second embodiment.

[0061] The blood pressure estimation device 2 performs steps S201 to S203 shown in Figure 8.

[0062] In step S201, the acquisition unit 11 acquires the pulse wave 101.

[0063] In the subsequent step S202, the calculation unit 12 calculates the diastolic blood pressure value 103 and the pulse rate value 104 from the acquired pulse wave 101.

[0064] In the subsequent step S203, the estimation unit 13 estimates the systolic blood pressure value 105 from the calculated diastolic blood pressure value 103 and the calculated pulse rate value 104.

[0065] Figure 6 is also a flowchart showing the process flow for creating a function used by the estimation unit provided in the blood pressure estimation device of the second embodiment.

[0066] When function 112 is created, steps S111 and S112 shown in Figure 6 are executed.

[0067] In step S111, multiple measurement groups are acquired by the blood pressure monitor. Each measurement group includes a measurement of the diastolic blood pressure, a measurement of the pulse rate, and a measurement of the systolic blood pressure. The blood pressure monitor only needs to be able to acquire highly accurate measurements of the diastolic blood pressure, pulse rate, and systolic blood pressure, for example, a general upper arm cuff blood pressure monitor.

[0068] In the subsequent step S112, a function 112 is created from the acquired set of measurements. During this process, multiple regression analysis is performed using the set of measurements to determine the coefficients included in the function 112.

[0069] 3. Third Embodiment The following describes the differences between the third embodiment and the first embodiment. For aspects not described, the same configuration as that used in the first embodiment is employed in the third embodiment.

[0070] Figure 9 is a block diagram of the blood pressure estimation device according to the third embodiment. Figure 10 is a diagram showing the information processed by the blood pressure estimation device according to the third embodiment.

[0071] The blood pressure estimation device 3 of the third embodiment shown in Figure 9 acquires the pulse wave 101 of a living organism, calculates the systolic blood pressure 102, the diastolic blood pressure 103, and the pulse rate 104 from the acquired pulse wave 101, estimates the diastolic blood pressure 106 from the calculated systolic blood pressure 102 and pulse rate 104, estimates the systolic blood pressure 105 from the calculated diastolic blood pressure 103 and pulse rate 104, obtains the corrected systolic blood pressure 107 from the calculated systolic blood pressure 102 and the estimated systolic blood pressure 105, and obtains the corrected diastolic blood pressure 108 from the calculated diastolic blood pressure 103 and the estimated diastolic blood pressure 106. In the blood pressure estimation device 3, one of the systolic blood pressure and diastolic blood pressure is the first blood pressure, and the other of the systolic blood pressure and diastolic blood pressure is the second blood pressure, which is different from the first blood pressure. Alternatively, the blood pressure estimation device 3 of the third embodiment may acquire the pulse wave 101 of the living body, calculate the systolic blood pressure value 102, the diastolic blood pressure value 103, and the period of the pulse wave 101 from the acquired pulse wave 101, estimate the diastolic blood pressure value 106 from the calculated systolic blood pressure value 102 and the calculated period, estimate the systolic blood pressure value 105 from the calculated diastolic blood pressure value 103 and the calculated period, obtain the corrected systolic blood pressure value 107 from the calculated systolic blood pressure value 102 and the estimated systolic blood pressure value 105, and obtain the corrected diastolic blood pressure value 108 from the calculated diastolic blood pressure value 103 and the estimated diastolic blood pressure value 106.

[0072] As shown in Figure 9, the blood pressure estimation device 3 comprises an acquisition unit 11, a calculation unit 12, an estimation unit 13, and a correction unit 14.

[0073] The calculation unit 12 calculates the systolic blood pressure value 102, the diastolic blood pressure value 103, and the pulse rate value 104 from the pulse wave 101. The calculated systolic blood pressure value 102, the diastolic blood pressure value 103, and the pulse rate value 104 are passed to the estimation unit 13, and the calculated systolic blood pressure value 102 and the diastolic blood pressure value 103 are passed to the correction unit 14. For example, the calculation unit 12 calculates the systolic blood pressure value 102 and the diastolic blood pressure value 103 from information such as the amplitude, wavelength, waveform characteristics, and frequency spectrum of the pulse wave 101, and calculates the pulse rate value 104 from information such as the period, frequency spectrum, spectrogram, and number of peaks of the pulse wave 101. For example, the pulse rate value 104 may be calculated by taking the reciprocal of the period of the pulse wave 101.

[0074] The estimation unit 13 estimates the diastolic blood pressure 106 from the calculated systolic blood pressure 102 and pulse rate 104 provided, estimates the systolic blood pressure 105 from the calculated diastolic blood pressure 103 and pulse rate 104 provided, and passes the estimated diastolic blood pressure 106 and systolic blood pressure 105 to the correction unit 14. The estimation unit 13 uses a first estimation formula prepared in advance for estimating the diastolic blood pressure 106 from the calculated systolic blood pressure 102 and pulse rate 104, and a second estimation formula for estimating the systolic blood pressure 105 from the calculated diastolic blood pressure 103 and pulse rate 104. The first estimation formula used is a function 111 of systolic blood pressure and pulse rate, and the second estimation formula used is a function 112 of diastolic blood pressure and pulse rate. The estimation unit 13 estimates the diastolic blood pressure 106 from the value of function 111 obtained by substituting the calculated systolic blood pressure 102 and the calculated pulse rate 104 into function 111, and estimates the systolic blood pressure 105 from the value of function 112 obtained by substituting the calculated diastolic blood pressure 103 and the calculated pulse rate 104 into function 112. For example, the estimation unit 13 uses the value of function 111 obtained by substituting the calculated systolic blood pressure 102 and the calculated pulse rate 104 into function 111 as the estimated diastolic blood pressure 106, and uses the value of function 112 obtained by substituting the calculated diastolic blood pressure 103 and the calculated pulse rate 104 into function 112 as the estimated systolic blood pressure 105. Alternatively, the estimation unit 13 may use the calculated value of the period of the pulse wave 101 instead of the calculated value of the pulse rate 104 to estimate the estimated value of the diastolic blood pressure 106, estimate the estimated value of the systolic blood pressure 105 from the calculated value of the period of the pulse wave 101, and pass the estimated diastolic blood pressure 106 and the estimated systolic blood pressure 105 to the correction unit 14.

[0075] The correction unit 14 obtains a corrected value 107 of systolic blood pressure from the provided calculated value 102 of systolic blood pressure and estimated value 105 of systolic blood pressure, and obtains a corrected value 108 of diastolic blood pressure from the provided calculated value 103 of diastolic blood pressure and estimated value 106 of diastolic blood pressure, and outputs the obtained corrected values ​​107 of systolic blood pressure and dias For example, the correction unit 14 may use the weighted average of the calculated systolic blood pressure value 102 and the estimated systolic blood pressure value 105 as the corrected systolic blood pressure value 107, or the weighted average of the calculated diastolic blood pressure value 103 and the estimated diastolic blood pressure value 106 as the corrected diastolic blood pressure value 108. In the weighted average of the calculated systolic blood pressure value 102 and the estimated systolic blood pressure value 105, the weights of the calculated systolic blood pressure value 102 and the estimated systolic blood pressure value 105 are different from each other. In the weighted average of the calculated diastolic blood pressure value 103 and the estimated diastolic blood pressure value 106, the weights of the calculated diastolic blood pressure value 103 and the estimated diastolic blood pressure value 106 are different from each other.

[0076] If the calculated systolic blood pressure value of 102 has high accuracy, then the estimated diastolic blood pressure value of 106 will also have high accuracy.

[0077] When the estimated diastolic blood pressure 106 has high accuracy, and the calculated diastolic blood pressure 103 also has high accuracy, then both the calculated diastolic blood pressure 103 and the estimated diastolic blood pressure 106, which form the basis of the corrected diastolic blood pressure 108, have high accuracy and are close to each other. Therefore, the corrected diastolic blood pressure 108 has high accuracy.

[0078] If the estimated diastolic blood pressure value 106 has high accuracy, but the calculated diastolic blood pressure value 103 has low accuracy, the calculated diastolic blood pressure value 103 with low accuracy is corrected by the estimated diastolic blood pressure value 106 with high accuracy to obtain the corrected diastolic blood pressure value 108. Therefore, the corrected diastolic blood pressure value 108 has higher accuracy than the calculated diastolic blood pressure value 103.

[0079] If the calculated minimum blood pressure value of 103 is highly accurate, then the estimated maximum blood pressure value of 105 will also be highly accurate.

[0080] When the estimated systolic blood pressure 105 has high accuracy, and the calculated systolic blood pressure 102 also has high accuracy, then both the calculated systolic blood pressure 102 and the estimated systolic blood pressure 105, which form the basis of the corrected systolic blood pressure 107, have high accuracy and are close to each other. Therefore, the corrected systolic blood pressure 107 has high accuracy.

[0081] If the estimated systolic blood pressure value 105 has high accuracy, but the calculated systolic blood pressure value 102 has low accuracy, the calculated systolic blood pressure value 102 with low accuracy is corrected by the estimated systolic blood pressure value 105 with high accuracy to obtain the corrected systolic blood pressure value 107. Therefore, the corrected systolic blood pressure value 107 has higher accuracy than the calculated systolic blood pressure value 102.

[0082] As a result, the corrected values ​​108 for diastolic blood pressure and 107 for systolic blood pressure have higher accuracy than the calculated values ​​103 for diastolic blood pressure and 102 for systolic blood pressure, respectively. In other words, the correction unit 14 contributes to improved accuracy.

[0083] Figure 11 is a flowchart showing the processing flow performed by the blood pressure estimation device of the third embodiment.

[0084] The blood pressure estimation device 3 performs steps S301 to S304 shown in Figure 11.

[0085] In step S301, the acquisition unit 11 acquires the pulse wave 101.

[0086] In the subsequent step S302, the calculation unit 12 calculates the systolic blood pressure value 102, the diastolic blood pressure value 103, and the pulse rate value 104 from the acquired pulse wave 101.

[0087] In the subsequent step S303, the estimation unit 13 estimates the diastolic blood pressure 106 from the calculated systolic blood pressure 102 and pulse rate 104, and estimates the systolic blood pressure 105 from the calculated diastolic blood pressure 103 and pulse rate 104.

[0088] In the subsequent step S304, the correction unit 14 obtains a corrected value 107 of the systolic blood pressure from the calculated value 102 of the systolic blood pressure and the estimated value 105 of the systolic blood pressure, and obtains a corrected value 108 of the diastolic blood pressure from the calculated value 103 of the diastolic blood pressure and the estimated value 106 of the diastolic blood pressure.

[0089] Figure 6 is also a flowchart showing the process flow for creating a function used by the estimation unit provided in the blood pressure estimation device of the third embodiment.

[0090] When functions 111 and 112 are created, steps S111 and S112 shown in Figure 6 are executed.

[0091] In step S111, multiple measurement groups are acquired by the blood pressure monitor. Each measurement group includes a systolic blood pressure measurement, a pulse rate measurement, and a diastolic blood pressure measurement. The blood pressure monitor only needs to be able to acquire highly accurate systolic blood pressure, pulse rate, and diastolic blood pressure measurements, for example, a general upper arm cuff blood pressure monitor.

[0092] In the subsequent step S112, functions 111 and 112 are created from the acquired set of measurements. At this time, multiple regression analysis is performed using the set of measurements to determine the coefficients included in functions 111 and 112.

[0093] This disclosure is not limited to the embodiments described above, and may be replaced with configurations that are substantially the same as those shown in the embodiments, configurations that produce the same effects, or configurations that can achieve the same purpose. [Explanation of Symbols]

[0094] 1,2,3 Blood pressure estimation device 11 Acquisition Department 12 Calculation Section 13 Estimation part 14 Correction section 21 Computer 31 processors 32 memory 33 Storage 41 Blood pressure estimation program 101 Pulse wave 102 Calculation of systolic blood pressure 103 Calculation value of diastolic blood pressure 104 Calculated pulse rate 105 Estimated systolic blood pressure 106 Estimated diastolic blood pressure 107 Corrected value of systolic blood pressure 108 Corrected value of diastolic blood pressure 111,112 Functions

Claims

1. A calculation unit that calculates a first blood pressure value and a pulse rate value from biological information showing the pulse wave of a living organism, An estimation unit that estimates a second blood pressure value different from the first blood pressure value from the first blood pressure value and the calculated pulse rate value, Equipped with, The first blood pressure mentioned above is the systolic blood pressure, The second blood pressure mentioned above is the diastolic blood pressure, The estimation unit estimates the diastolic blood pressure from the value of the function obtained by substituting the calculated values ​​of the systolic blood pressure and the calculated values ​​of the pulse rate into a function of the systolic blood pressure and the pulse rate that includes the factor SYS γ_1 × HR γ_2, where SYS is the systolic blood pressure and HR is the pulse rate. Blood pressure estimation device.

2. A calculation unit that calculates a first blood pressure value and a pulse rate value from biological information showing the pulse wave of a living organism, An estimation unit that estimates a second blood pressure value different from the first blood pressure value from the first blood pressure value and the calculated pulse rate value, Equipped with, The first blood pressure is the diastolic blood pressure, The second blood pressure mentioned above is the systolic blood pressure, The estimation unit estimates the systolic blood pressure from the value of the function obtained by substituting the calculated values ​​of the diastolic blood pressure and the calculated value of the pulse rate into a function of the diastolic blood pressure and the pulse rate that includes the factor DIA γ_1 × HR γ_2, where DIA is the diastolic blood pressure and HR is the pulse rate. Blood pressure estimation device.

3. A calculation unit that calculates a first blood pressure value and a pulse wave period value from biological information showing the pulse wave of a living organism, An estimation unit that estimates a second blood pressure value different from the first blood pressure value from the first blood pressure value and the period value, Equipped with, The first blood pressure mentioned above is the systolic blood pressure, The second blood pressure mentioned above is the diastolic blood pressure, The estimation unit estimates the diastolic blood pressure from the value of the function obtained by substituting the calculated values ​​of the systolic blood pressure and the period into a function of the systolic blood pressure and the period that includes the factor SYS γ_1 × T γ_2, where SYS is the systolic blood pressure and T is the period. Blood pressure estimation device.

4. A calculation unit that calculates a first blood pressure value and a pulse wave period value from biological information showing the pulse wave of a living organism, An estimation unit that estimates a second blood pressure value different from the first blood pressure value from the first blood pressure value and the period value, Equipped with, The first blood pressure mentioned above is the diastolic blood pressure. The second blood pressure mentioned above is the systolic blood pressure, The estimation unit estimates the systolic blood pressure from the value of the function obtained by substituting the calculated values ​​of the diastolic blood pressure and the period into a function of the diastolic blood pressure and the period that includes the factor DIA γ_1 × T γ_2, where DIA is the diastolic blood pressure and T is the period. Blood pressure estimation device.

5. The calculation unit calculates the second blood pressure value from the biological information, The estimation unit estimates the first blood pressure value from the second blood pressure value and the pulse rate value, The system includes a correction unit that obtains a corrected value of the first blood pressure from the calculated value and estimated value of the first blood pressure, and obtains a corrected value of the second blood pressure from the calculated value and estimated value of the second blood pressure. The blood pressure estimation device according to claim 1 or 2.

6. The calculation unit calculates the second blood pressure value from the biological information, The estimation unit estimates the first blood pressure value from the second blood pressure value and the period value, The system includes a correction unit that obtains a corrected value of the first blood pressure from the calculated value and estimated value of the first blood pressure, and obtains a corrected value of the second blood pressure from the calculated value and estimated value of the second blood pressure. The blood pressure estimation device according to claim 3 or 4.

7. Calculating a first blood pressure value and a pulse rate value from biological information showing the pulse wave of a living organism, To estimate a second blood pressure value different from the first blood pressure value from the first blood pressure value and the calculated pulse rate value, Includes, The first blood pressure mentioned above is the systolic blood pressure, The second blood pressure mentioned above is the diastolic blood pressure, In estimating the second blood pressure estimate, when the systolic blood pressure is SYS and the pulse rate is HR, the diastolic blood pressure estimate is estimated from the value of the function obtained by substituting the calculated values ​​of the systolic blood pressure and the calculated values ​​of the pulse rate into a function of the systolic blood pressure and the pulse rate that includes the factor SYS γ_1 × HR γ_2. Methods for estimating blood pressure.

8. Calculating a first blood pressure value and a pulse wave period value from biological information showing the pulse wave of a living organism, Estimating a second blood pressure value different from the first blood pressure value from the first blood pressure value and the period value, Includes, The first blood pressure mentioned above is the systolic blood pressure, The second blood pressure mentioned above is the diastolic blood pressure, In estimating the second blood pressure estimate, the diastolic blood pressure estimate is obtained from the value of the function obtained by substituting the calculated values ​​of the systolic blood pressure and the period into a function of the systolic blood pressure and the period that includes the factor SYS γ_1 × T γ_2, where SYS is the systolic blood pressure and T is the period. Methods for estimating blood pressure.

9. Calculating a first blood pressure value and a pulse rate value from biological information showing the pulse wave of a living organism, To estimate a second blood pressure value different from the first blood pressure value from the first blood pressure value and the calculated pulse rate value, Have the computer run it, The first blood pressure mentioned above is the systolic blood pressure, The second blood pressure mentioned above is the diastolic blood pressure, In estimating the second blood pressure estimate, when the systolic blood pressure is SYS and the pulse rate is HR, the diastolic blood pressure estimate is estimated from the value of the function obtained by substituting the calculated values ​​of the systolic blood pressure and the calculated values ​​of the pulse rate into a function of the systolic blood pressure and the pulse rate that includes the factor SYS γ_1 × HR γ_2. Blood pressure estimation program.

10. Calculating a first blood pressure value and a pulse wave period value from biological information showing the pulse wave of a living organism, Estimating a second blood pressure value different from the first blood pressure value from the first blood pressure value and the period value, Have the computer run it, The first blood pressure mentioned above is the systolic blood pressure, The second blood pressure mentioned above is the diastolic blood pressure, In estimating the second blood pressure estimate, the diastolic blood pressure estimate is obtained from the value of the function obtained by substituting the calculated values ​​of the systolic blood pressure and the period into a function of the systolic blood pressure and the period that includes the factor SYS γ_1 × T γ_2, where SYS is the systolic blood pressure and T is the period. Blood pressure estimation program.

11. Each measurement group includes a first blood pressure measurement, a pulse rate measurement, and a second blood pressure measurement different from the first blood pressure, and multiple measurement groups are acquired by the blood pressure monitor. Creating a function of the first blood pressure and pulse rate from the aforementioned group of measurement values, The calculation of the first blood pressure value and the calculation of the pulse rate value from biological information showing the pulse wave of the living body, The second estimated blood pressure value is estimated from the value of the function obtained by substituting the first calculated blood pressure value and the calculated pulse rate value into the function, Includes, The first blood pressure mentioned above is the systolic blood pressure, The second blood pressure mentioned above is the diastolic blood pressure, In estimating the second blood pressure estimate, when the systolic blood pressure is SYS and the pulse rate is HR, the diastolic blood pressure estimate is estimated from the value of the function obtained by substituting the calculated values ​​of the systolic blood pressure and the calculated values ​​of the pulse rate into a function of the systolic blood pressure and the pulse rate that includes the factor SYS γ_1 × HR γ_2. Methods for estimating blood pressure.

12. Each measurement group includes a first blood pressure measurement, a pulse wave period measurement, and a second blood pressure measurement different from the first blood pressure, and multiple measurement groups are acquired by the blood pressure monitor. Creating a function of the first blood pressure and the period from the aforementioned group of measurement values, The calculation of the first blood pressure value and the calculation of the period from the biological information showing the pulse wave of the living body, The second estimated blood pressure value is estimated from the value of the function obtained by substituting the first calculated blood pressure value and the period calculated value into the function, Includes, The first blood pressure mentioned above is the systolic blood pressure, The second blood pressure mentioned above is the diastolic blood pressure, In estimating the second blood pressure estimate, the diastolic blood pressure estimate is obtained from the value of the function obtained by substituting the calculated values ​​of the systolic blood pressure and the period into a function of the systolic blood pressure and the period that includes the factor SYS γ_1 × T γ_2, where SYS is the systolic blood pressure and T is the period. Methods for estimating blood pressure.

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