Sphygmomanometer

Abstract

The present invention enables both blood pressure measurement and atrial fibrillation determination while reducing the burden on a user. A sphygmomanometer (20) measures the blood pressure of a user on the basis of a pulse wave signal superimposed on a cuff pressure signal detected during pressurization or decompression of cuff pressure indicating the internal pressure of a cuff worn on a measurement site of the user. A sphygmomanometer (20) is provided with: an information acquisition unit that acquires pulse wave characteristic information indicating a characteristic quantity of a pulse wave from a pulse wave signal superimposed on a cuff pressure signal detected during each blood pressure measurement; a storage unit for storing the acquired pulse wave feature information for each blood pressure measurement; a pulse rate determination unit that determines the number of pulse waves having a feature quantity indicated by pulse wave feature information for each blood pressure measurement; and an atrial fibrillation determination unit that determines atrial fibrillation in the pulse waves on the basis of the pulse wave feature information in the storage unit when the total number of pulse waves for each blood pressure measurement reaches a predetermined number.

Description

Technical Field

[0001] The present disclosure relates to a sphygmomanometer, and more particularly, to a sphygmomanometer capable of determining atrial fibrillation. Background Art

[0002] People want to find atrial fibrillation (Atrial fibrillation), which is the cause of heart disease, as early as possible. In the past, a technology for estimating atrial fibrillation based on pulse wave information obtained by a home electronic blood pressure monitor has been proposed. Specifically, in one measurement opportunity using an electronic blood pressure monitor, for example, multiple blood pressure measurements are continuously performed, and the interval between the pulse wave signals obtained in each blood pressure measurement, i.e., the pulse wave interval, is obtained, and atrial fibrillation is detected based on the pulse wave interval.

[0003] For example, US Patent Application Publication No. 2016 / 0228017 (Patent Document 1) discloses a blood pressure measurement device that can indicate the presence or absence of atrial fibrillation.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: U.S. Patent Application Publication No. 2016 / 0228017 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In the device disclosed in Patent Document 1, it is necessary to continuously perform blood pressure measurement three times in one measurement opportunity in order to determine the presence or absence of atrial fibrillation. In this way, blood pressure is always measured three times in each measurement opportunity, which takes a long time to measure and causes the user to feel constrained because the measurement site is compressed by the cuff. This is a burden for the user.

[0009] The present disclosure provides a blood pressure meter that can reduce the burden on a user and can perform both blood pressure measurement and atrial fibrillation determination.

[0010] Technical Solution

[0011] The sphygmomanometer of the present disclosure comprises: a cuff pressure adjustment unit for increasing or decreasing the cuff pressure indicating the internal pressure of the cuff attached to the measurement site of the user; a cuff pressure detection unit for detecting a cuff pressure signal indicating the cuff pressure; a blood pressure measurement unit for measuring the user's blood pressure based on a pulse wave signal superimposed on the cuff pressure signal detected in the process of increasing or decreasing the cuff pressure; an information acquisition unit for acquiring pulse wave characteristic information indicating a characteristic amount of the pulse wave from the pulse wave signal superimposed on the cuff pressure signal detected in the blood pressure measurement each time the blood pressure is measured; a storage unit for storing the acquired pulse wave characteristic information for each blood pressure measurement; a pulse number determination unit for determining the number of pulse waves having the characteristic amount indicated by the pulse wave characteristic information for each blood pressure measurement; and an atrial fibrillation determination unit for determining atrial fibrillation in the pulse wave based on the pulse wave characteristic information in the storage unit when the total number of pulse waves for each blood pressure measurement reaches a predetermined number.

[0012] According to the above disclosure, atrial fibrillation in the pulse wave is determined based on the pulse wave characteristic information stored in the storage unit when the total number of pulse waves in each blood pressure measurement reaches a predetermined number. As a result, it is not necessary to perform multiple blood pressure measurements for atrial fibrillation determination in one blood pressure measurement opportunity. As a result, in blood pressure measurement, the burden on the user caused by repeated compression of the measurement site of the user and the increase in blood pressure measurement time can be reduced, and both blood pressure measurement and atrial fibrillation determination can be achieved.

[0013] The pulse rate determination unit in the above-mentioned sphygmomanometer determines the number of pulse waves in each blood pressure measurement by excluding pulse wave characteristic information corresponding to blood pressure measurement for which the elapsed time from the blood pressure measurement is greater than a threshold value from the pulse wave characteristic information in each blood pressure measurement.

[0014] According to the above-described blood pressure monitor, old and past pulse wave characteristic information can be excluded in advance from the pulse wave characteristic information used to determine atrial fibrillation.

[0015] In the above-mentioned blood pressure monitor, the pulse wave feature amount represented by the pulse wave feature information includes an interval of the pulse wave represented by a pulse wave signal superimposed on a cuff pressure signal detected in blood pressure measurement.

[0016] According to the above-described sphygmomanometer, the pulse wave interval can be included in the pulse wave feature amount used for determining atrial fibrillation.

[0017] In the above-mentioned sphygmomanometer, the interval between pulse waves includes a time interval between maximum amplitude values ​​in adjacent pulse waves.

[0018] According to the above-mentioned sphygmomanometer, the pulse wave interval can include the time interval of the maximum amplitude.

[0019] In the above-mentioned sphygmomanometer, the pulse rate determination unit determines the number of pulse waves for each blood pressure measurement by excluding pulse wave characteristic information corresponding to a pulse wave having a characteristic amount represented by the pulse wave characteristic information for each blood pressure measurement and having an amplitude less than a threshold value.

[0020] According to the above-described blood pressure monitor, pulse wave characteristic information corresponding to a pulse wave having an amplitude equal to or smaller than a threshold value can be excluded in advance from pulse wave characteristic information used to determine atrial fibrillation.

[0021] In the above-mentioned sphygmomanometer, the pulse rate determination unit further determines whether the total number of pulse wave rates corresponding to the pulse wave characteristic information for each blood pressure measurement in the storage unit has reached a predetermined number.

[0022] According to the above sphygmomanometer, when the pulse rate determination unit determines that the total number of pulse wave rates corresponding to the pulse wave characteristic information for each blood pressure measurement in the storage unit has reached a predetermined number, atrial fibrillation can be determined in the pulse wave based on the pulse wave characteristic information stored in the storage unit.

[0023] Effects of the Invention

[0024] In the present disclosure, it is possible to reduce the burden on the user and perform both blood pressure measurement and atrial fibrillation determination. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 FIG. 1 is a diagram showing an example of a network configuration of a blood pressure measurement system to which the present embodiment is applied.

[0026] Figure 2 This is a block diagram showing an example of the hardware configuration of the sphygmomanometer 20 according to the present embodiment.

[0027] Figure 3 This is a diagram showing an example of the functional configuration of the sphygmomanometer 20 according to the present embodiment.

[0028] Figure 4 This is a flowchart showing an example of the measurement process of the sphygmomanometer 20 according to the present embodiment.

[0029] Figure 5 Yes means Figure 4 A flowchart of an example of a process of blood pressure measurement.

[0030] Figure 6 It is a diagram showing an example of information display on the display 31 according to the present embodiment.

[0031] Figure 7 It is a diagram showing an example of information display on the display 31 according to the present embodiment.

[0032] Figure 8FIG. 1 is a diagram showing an example of a plurality of pulse waves for AF determination according to the present embodiment. DETAILED DESCRIPTION

[0033] Hereinafter, the embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same components are marked with the same reference numerals. Their names and functions are also the same. Therefore, they will not be described in detail again.

[0034] <Application Examples>

[0035] Reference Figure 3 , an application example of the blood pressure monitor of this embodiment is described. Figure 3 1 is a diagram showing an example of the functional configuration of the sphygmomanometer 20 according to the present embodiment. Hereinafter, atrial fibrillation (Atrial fibrillation) is referred to as AF.

[0036] The sphygmomanometer 20 of this embodiment is configured to measure blood pressure by increasing or decreasing the cuff pressure indicating the internal pressure of a cuff (air bag) wrapped around a measurement site, such as an arm, worn by the user. The measurement site is not limited to the upper arm.

[0037] Reference Figure 3 The sphygmomanometer 20 includes a blood pressure measuring unit 220, an AF determination unit 230, an output control unit 240 for controlling the output of information, and a storage control unit 250 for controlling the reading and writing of information to the storage unit 36 ​​as main functional components. These components are implemented, for example, by the processor 30 of the sphygmomanometer 20 reading a program stored in a storage device such as a HDD (Hard Disk Drive) 35 described later, expanding and executing the read program in the memory 33 described later. It should be noted that some or all of these components may be implemented by hardware circuits including ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array).

[0038] The storage unit 36 ​​is configured to include a later-described HDD 35 or a later-described memory 33. The storage unit 36 ​​includes a working storage area 361 mainly composed of a volatile storage medium and an information storage area. In the information storage area, information including interval information 362, blood pressure measurement information 363 indicating information of the measured blood pressure, and AF determination information 364 indicating the determination result of AF is stored. The interval information 362 indicates the interval of the pulse wave as an example of a feature amount of the pulse wave detected in time series from the measurement site in the blood pressure measurement.

[0039] The blood pressure measuring unit 220 measures the blood pressure of the user based on the pulse wave signal superimposed on the cuff pressure signal indicating the cuff pressure detected by the pressure sensor 22, and uses the following instructions indicated by the user's operation of the blood pressure measuring unit and the sphygmomanometer to measure the blood pressure of the user. Figure 2 Specifically, the blood pressure measuring unit 220 controls the pump 23 to be driven via the pump driving circuit 26 and the valve 24 to be driven via the valve driving circuit 27. The valve 24 is controlled to be opened / closed to discharge or seal air in the fluid bag to adjust the cuff pressure.

[0040] The blood pressure measuring unit 220 receives the cuff pressure signal detected by the pressure sensor 22, and extracts a pulse wave signal indicating the pulse wave of the measured part superimposed on the cuff pressure signal. That is, the blood pressure measuring unit 220 detects the pressure component, i.e., the time-series pulse wave, which is superimposed on the cuff pressure signal in synchronization with the pulsation of the user's heart from the cuff pressure signal. The pulse wave signal of the analog signal measured by the pressure sensor 22 is converted into pulse wave information of the digital signal. The interval calculating unit 221 included in the blood pressure measuring unit 220 calculates the interval between adjacent pulse waves in the time-series pulse wave constituting the pulse wave information. The interval calculating unit 221 generates interval information 362 indicating the interval between adjacent pulse waves constituting the group for each group consisting of two adjacent pulse waves in the time-series pulse wave. The interval information 362 is stored in the storage unit 36 ​​through the storage control unit 250. In the present embodiment, the interval between pulse waves indicates, for example, the time from when a peak with the largest amplitude of a pulse wave signal is detected to when the next peak of the amplitude of a pulse wave signal is detected.

[0041] The interval calculation unit 221 is an example of an "information acquisition unit" that acquires the characteristic amount of the pulse wave. Figure 3 In the figure, the interval calculation unit 221 is shown as a function included in the blood pressure measurement unit 220, but it can also be provided as a function independent of the blood pressure measurement unit 220. It should be noted that the feature amount is set as the interval of the pulse wave, but it is not limited to the interval.

[0042] The blood pressure measurement unit 220 calculates blood pressure measurement information 363 indicating the user's blood pressure based on the pulse wave signal. The blood pressure measurement information 363 is stored in the storage unit 36, and is output to the output control unit 240 as a measurement result. Specifically, in the blood pressure measurement, the cuff pressure is increased to a predetermined pressure. Based on the pulse wave signal detected in the subsequent decompression process, the blood pressure measurement unit 220 measures the user's blood pressure according to the oscillometric method, outputs the measurement result to the output control unit 240, and stores the blood pressure measurement information 363 including the measurement result in the storage unit 36 ​​via the storage control unit 250. Typically, the blood pressure measurement information 363 calculated by the blood pressure measurement unit 220 includes systolic blood pressure, diastolic blood pressure, and pulse rate.

[0043] In the AF determination process performed by the AF determination unit 230, the pulse rate determination unit 232 analyzes the interval information 362 stored in the storage unit 36, and determines whether the number of pulse waves corresponding to the interval information 362 has reached a predetermined number based on the analysis result. In response to the pulse rate determination unit 232 determining that the number of pulse waves corresponding to the interval information 362 has reached a predetermined number, the AF determination unit 230 performs a predetermined process based on the interval information 362 corresponding to the predetermined number of pulse waves in the storage unit 36, thereby determining the presence or absence of AF in the pulse wave. The predetermined process is a process for detecting AF, for example, determining the presence or absence of AF using a pulse wave interval pattern. The peak value (maximum point) of the amplitude of each beat is detected in the pulse wave signal, and the time interval between the peak value of the current beat and the peak value of the previous beat is calculated as the pulse wave interval. It should be noted that the interval used for determination is not limited to the interval of the peak value, and may also be the interval between the rising points of adjacent pulse waves.

[0044] The determination result of the above-described AF determination process is output to the output control section 240 , and AF determination information 364 indicating the determination result is stored in the storage section 36 .

[0045] The output control unit 240 generates display data for displaying the blood pressure value and the result of AF determination based on the measurement result from the blood pressure measurement unit 220 and the determination result from the AF determination unit 230, and outputs the display data to the display control circuit 31A. The display control circuit 31A drives the display 31 based on the display data, so that the blood pressure value and the information of AF determination are displayed on the display 31.

[0046] Furthermore, in the AF determination process, a group of pulse waves for which AF determination is performed with high accuracy is selected by the selection unit 231 included in the AF determination unit 230. Specifically, for each of a plurality of groups of pulse waves indicated by the interval information 362 stored in the storage unit 36, the selection unit 231 deletes from the interval information 362 a group of pulse numbers corresponding to blood pressure measurements for which the elapsed time from the time when the pulse wave was measured (blood pressure measurement date and time) is greater than or equal to a threshold value.

[0047] Furthermore, in the AF determination process, the selection unit 231 compares the peak value of the amplitude of the pulse wave signal with the threshold value for each of the plurality of groups of pulse waves indicated by the interval information 362 stored in the storage unit 36. The selection unit 231 detects a group of pulse waves having an amplitude corresponding to a peak value smaller than the threshold value based on the comparison result, and deletes the detected group from the interval information 362.

[0048] The processing of the pulse rate determination unit 232 and the AF determination unit 230 is performed on the interval information 362 after the selective deletion of the pulse wave group by the selection unit 231. As a result, the information of the pulse wave of the old past measurement date and time or the pulse wave with insufficient amplitude is excluded from the information of the pulse wave used for AF determination. Therefore, it is possible to prevent such information from acting as noise, thereby improving the AF determination accuracy. It should be noted that the method of selecting the pulse wave to be deleted may be one of the selection based on the elapsed time from the measurement time and the selection based on the amplitude of the pulse wave signal, or both.

[0049] According to the above-mentioned sphygmomanometer 20, AF determination is performed based on the interval information 362 corresponding to the predetermined number of pulse waves stored in the storage unit 36 ​​when the total number of pulse waves acquired in each blood pressure measurement reaches a predetermined number. In this way, the trigger for AF determination is not the number of blood pressure measurements, but the total number of pulse waves acquired by the measurement reaches a predetermined number. Therefore, it is not necessary to perform blood pressure measurement three times in succession every time blood pressure measurement is performed in order to perform AF determination as in Patent Document 1, and thus the burden on the user can be reduced.

[0050] <Network Configuration>

[0051] Figure 1 FIG. 2 is a diagram showing an example of a network configuration of the sphygmomanometer 20 to which this embodiment is applied. Figure 1The network system 1 includes a sphygmomanometer 20, a server 40, and portable information processing terminals 10A and 10B such as smart phones that can be connected to the network. The sphygmomanometer 20 communicates with the terminal 10A via the network 10. The terminal 10A and the terminal 10B communicate with the server 40 via the network 15. The information measured in the sphygmomanometer 20 can be transmitted to the server 40 and stored in the database 42. The networks 10 and 15 are configured to include various communication networks such as Wi-Fi (registered trademark), mobile communication networks, and the Internet.

[0052] The sphygmomanometer 20 may include different types of sphygmomanometers 20A, 20B, and 20C. The sphygmomanometer 20 is a fixed upper arm sphygmomanometer in which the main body and the cuff 21 are separate bodies. The sphygmomanometer 20B is a watch-type wrist sphygmomanometer in which the main body and the cuff are integrated. The sphygmomanometer 20C is configured such that the cuff and the main body are integrated, and the sphygmomanometer 20C is worn on the upper arm, for example. Hereinafter, for ease of explanation, the sphygmomanometers 20A, 20B, and 20C are sometimes collectively referred to as "sphygmomanometer 20". Regardless of the type of sphygmomanometer, it is configured to be able to perform the above-mentioned blood pressure measurement and AF judgment. In the present embodiment, the sphygmomanometer 20 is described by taking the sphygmomanometer 20A as an example.

[0053] The terminals 10A and 10B are, for example, smartphones having a touch panel constituting a display. The terminal 10A receives measurement information from the sphygmomanometer 20, displays the received measurement information on the display, and transmits the received measurement information to the server 40 to store it in the database 42. The terminal 10B communicates with the server 40, receives the measurement information retrieved from the database 42, and displays it on the display. Even if the sphygmomanometer 20 is a fixed type, the user can obtain the information measured by the sphygmomanometer 20 using the portable terminals 10A and 10B.

[0054] In this embodiment, Figure 3 The function is installed in the sphygmomanometer 20, but the installation method is not limited to this. For example, the sphygmomanometer 20 and multiple devices such as the server 40, the terminals 10A, 10B, etc. may cooperate to form a system. In the case of such multiple devices cooperating, the processing to realize the function of the blood pressure measurement system can be realized by distributed processing among such multiple devices. As a distributed processing, for example Figure 3 The AF determination unit 230 among the functions of the sphygmomanometer 20 may be installed in the terminal 10A or the server 40. In addition, the storage unit 36 ​​may be configured in the database 42 of the server 40 or the terminals 10A and 10B. It should be noted that the distribution method is not limited to this.

[0055] <Hardware Configuration>

[0056] Figure 22 is a block diagram showing an example of the hardware configuration of the sphygmomanometer 20 according to the present embodiment. Figure 2 The sphygmomanometer 20 includes a main body and a cuff 21 as main components. The cuff 21 contains a fluid bag containing air. The main body includes: a processor 30; an air system component, which constitutes a "cuff pressure adjustment unit" for blood pressure measurement; an A / D conversion circuit 25; a pump drive circuit 26; a valve drive circuit 27; a display 31, which is connected to a display control circuit 31A; a storage unit 36; an operation unit 32, which accepts user operations for the sphygmomanometer 20; a communication interface 28, which connects the sphygmomanometer 20 to a network in a communicative manner; a reader / writer 29, which is freely installed with a non-volatile storage medium such as a memory card 29A; and a power supply 34.

[0057] The processor 30 constitutes a calculation processing circuit such as a CPU (Central Processing Unit) and an MPU (MicroProcessing Unit). The processor 30 reads out and executes a program from the storage unit 36 ​​to realize the processing of the sphygmomanometer 20. For example, the processor 30 controls the driving pump 23 and the valve 24 in response to an operation signal from the operation unit 32. In addition, the processor 30 calculates the blood pressure value using an algorithm for blood pressure calculation by an oscillometric method, and displays the blood pressure value on the display 31.

[0058] The storage unit 36 ​​includes a nonvolatile storage medium such as the HDD 35 and a memory 33. The memory 33 includes a volatile or nonvolatile storage medium. The memory 33 includes, for example, a RAM (Random Access Memory), a ROM (Read-Only Memory), a flash memory, and the like. The memory 36 stores: a program for controlling the sphygmomanometer 20; data for controlling the sphygmomanometer 20; setting data for setting various functions of the sphygmomanometer 20; and information on the measurement results of the blood pressure value. In addition, the memory 33 is also used as a working memory for the processor 30 to expand and execute the program read from the storage unit 36.

[0059] The air system component pressurizes or depressurizes the cuff pressure indicating the internal pressure of the cuff 21 worn on the measurement site of the user. Specifically, in order to supply air to or discharge air from the fluid bag contained in the cuff 21 through the gas piping, the air system component includes: a pressure sensor 22 for detecting the pressure in the fluid bag, i.e., the cuff pressure; and a pump 23 and a valve 24 as an expansion and contraction mechanism for expanding and contracting the fluid bag.

[0060] The pressure sensor 22 detects the pressure in the fluid bag (cuff pressure) and outputs a signal (cuff pressure signal) corresponding to the detected pressure to the A / D conversion circuit 25. The pressure sensor 22 is, for example, a piezo-resistance pressure sensor, and is fluidically connected to the pump 23, the valve 24, and the fluid bag contained in the cuff 21 via a gas pipe. In order to pressurize the cuff pressure, the pump 23 supplies air as a fluid to the fluid bag via the gas pipe. The control valve 24 is opened / closed, thereby discharging the air in the fluid bag or sealing the air into the fluid bag via the gas pipe to control the cuff pressure.

[0061] The A / D conversion circuit 25 converts the output value (e.g., resistance) of the pressure sensor 22 from an analog signal into a digital signal and outputs it to the processor 30. In this example, the processor 30 functions as an oscillation circuit that oscillates at a frequency corresponding to the change in resistance caused by the piezoresistive effect from the pressure sensor 22, and the processor 30 obtains a signal indicating the cuff pressure based on the oscillation frequency. The pump drive circuit 26 controls the drive of the pump 23 based on the control signal given by the processor 30. The valve drive circuit 27 controls the opening / closing of the valve 24 based on the control signal given by the processor 30.

[0062] When measuring blood pressure according to the oscillometric method, the following actions are generally performed. Specifically, the cuff 21 is pre-wound around the measured part (wrist, arm, etc.) of the user (subject), and during the measurement, the pump 23 and the valve 24 are controlled to pressurize the cuff 21. During the pressurization process, when the cuff pressure is pressurized to the specified pressure Cp, the pump 23 is stopped and the valve 24 is gradually opened. In this way, the cuff pressure is decompressed. During the decompression process, the change in arterial volume generated in the artery of the measured part is extracted as a pulse wave signal superimposed on the cuff pressure signal. Based on the change in the amplitude of the pulse wave signal accompanied by the change in the cuff pressure during the decompression process (mainly rising and falling), the systolic blood pressure and the diastolic blood pressure are calculated. It should be noted that such blood pressure measurement is not limited to the case implemented during the decompression process, and can also be implemented using the pulse wave signal detected during the pressurization process and superimposed on the cuff pressure signal.

[0063] The operation unit 32 receives the user's operation on the blood pressure meter 20, and outputs an operation signal indicating the received user operation to the processor 30. The processor 30 outputs instructions based on the operation signal to each unit. The operation unit 32 includes a measurement switch 32A that is operated to instruct the start of blood pressure measurement. The operation unit 32 may also include other types of switches or buttons.

[0064] When the measurement switch 32A is operated, the processor 30 controls the air system to compress the measurement site through the cuff 21 and calculates the blood pressure value by the oscillometric method. When the measurement switch 32A is operated again during the blood pressure measurement, the processor 30 stops the blood pressure measurement.

[0065] The reader / writer 29 reads a program or data from the mounted memory card 29A. The processor 30 stores the read program or data in the storage unit 36. The reader / writer 29 also writes information such as measurement results read from the storage unit 36 ​​by the processor 30 into the mounted memory card 29A.

[0066] The display 31 displays various information including blood pressure measurement results, AF determination information, etc. based on a display signal from the display control circuit 31A. The communication interface 28 is configured to include, for example, a NIC (Network Interface Card) to control the exchange of information between the sphygmomanometer 20 and other devices (terminals 10A, 10B and server 40). The power supply unit 34 supplies power to the processor 30 and various hardware.

[0067] <Flowchart and Display Example>

[0068] Figure 4 1 is a flowchart showing an example of the measurement process of the sphygmomanometer 20 according to the present embodiment. When the process starts, the cuff 21 of the sphygmomanometer 20 is attached (wrapped) around the measurement site of the user.

[0069] Reference Figure 4 The processor 30 of the sphygmomanometer 20 receives an operation signal of the measurement switch 32A from the operation unit 32 based on the user's operation (step S1). The processor 30 starts the blood pressure measurement process in response to the operation signal (step S2). During the blood pressure measurement process, the interval information 362 is stored in the storage unit 36. The details of the blood pressure measurement process will be described later.

[0070] The processor 30 detects the number of pulse waves corresponding to the interval information 362 stored in the storage unit 36, and determines whether the number of detected pulse waves reaches a predetermined number (step S4). When the processor 30 determines that the number of pulse waves reaches a predetermined number (yes in step S4), the above-mentioned AF determination process is implemented (step S5). In the AF determination process of step S5, the processor 30 extracts the interval information corresponding to the predetermined number of pulse waves from the interval information 362 of the storage unit 36, and determines the presence or absence of AF in the pulse wave based on the extracted interval information.

[0071] The processor 30 outputs display data for causing the display 31 to display the result of the AF determination in step S5 (step S6 ) to the display control circuit 31A.

[0072] On the other hand, when processor 30 does not determine that the number of pulse waves has reached the predetermined number (NO in step S4 ), the AF determination in step S5 and the display of the determination result (steps S5 and S6 ) are not performed, and the process ends.

[0073] Figure 5 Yes means Figure 4 A flowchart of an example of the processing of blood pressure measurement. Figure 5 In the process, the processor 30 initializes the pressure sensor 22 in a state where the pump 23 is disconnected (stopped) and the valve 24 is opened (step S21). In the initialization of the pressure sensor 22, the output value of the pressure sensor 22 at the current time point is set to a value equivalent to the atmospheric pressure. In step S21, the processor 30 initializes the operation storage area 361 of the storage unit 36.

[0074] The processor 30 closes the valve 24 via the valve drive circuit 27 (step S22 ). Next, the processor 30 turns on (activates) the pump 23 via the pump drive circuit 26 to start pressurizing the cuff 21 (fluid bag) at a predetermined pressurization speed (step S23 ).

[0075] The processor 30 compares the cuff pressure indicated by the cuff pressure signal detected by the pressure sensor 22 with the prescribed pressure Cp, and determines whether the cuff pressure has reached the prescribed pressure Cp based on the comparison result (step S24). If it is not determined that the cuff pressure has reached the prescribed pressure Cp (No in step S24), the processor 30 returns to step S23 to pressurize the cuff 21 at a prescribed pressurization speed.

[0076] When it is determined that the cuff pressure has reached the predetermined pressure Cp (Yes in step S24), the processor 30 turns off (stops) the pump 23 via the pump drive circuit 26 (step S25). Thereafter, the processor 30 gradually opens the valve 24 via the valve drive circuit 27 so that the cuff 21 is decompressed at a predetermined decompression rate according to the cuff pressure indicated by the cuff pressure signal detected by the pressure sensor 22 (step S26).

[0077] During the decompression process of implementing the decompression at the predetermined speed, the processor 30 extracts the pulse wave signal from the cuff pressure signal detected by the pressure sensor 22, attempts to calculate the highest blood pressure (systolic blood pressure) and the lowest blood pressure (diastolic blood pressure) based on the extracted pulse wave signal, and determines whether the blood pressure calculation is completed (step S28). The processor 30 stores the pulse wave signal detected during the decompression process in the working storage area 361. When the processor 30 determines that the blood pressure calculation is not completed due to insufficient acquisition of the pulse wave signal or the like based on the pulse wave signal stored in the working storage area 361 (no in step S28), the processor 30 returns to step S26. When it is determined that the blood pressure calculation is completed (yes in step S28), the processor 30 sets the valve 24 to be fully opened via the valve drive circuit 27 to rapidly exhaust the air in the cuff 21 (step S29). The processor 30 displays the blood pressure value (measurement result) measured in step S27 on the display 31 (step S30). In addition, blood pressure measurement information 363 indicating the blood pressure value (measurement result) is stored in the storage unit 36 ​​.

[0078] Processor 30 calculates the interval between pulse waves for each group of a plurality of pulse waves represented by the pulse wave signal stored in working storage area 361 (step S31 ), and stores interval information 362 indicating the calculated interval between each group in storage unit 36 ​​(step S32 ).

[0079] Thus, in this embodiment, each time blood pressure is measured, interval information 362 is obtained for a plurality of pulse waves corresponding to the pulse wave signal used for calculating the blood pressure. Thus, interval information 362 obtained each time blood pressure is measured is stored in the storage unit 36 ​​in association with the measurement date and time of the corresponding blood pressure measurement.

[0080] Figure 6 and Figure 7 It is a diagram showing an example of information display on the display 31 according to the present embodiment. Figure 6 In the case where the AF determination process (step S5) is performed after the blood pressure measurement (step S2), a display example when AF is determined to exist is shown. Figure 6 In the figure, the results of the blood pressure measurement (systolic blood pressure SYS, diastolic blood pressure DIA, pulse rate PLS) and a message 311 indicating that AF is determined to be present are displayed.

[0081] In contrast, Figure 7 This is a display example showing a case where the AF determination process (step S5) is not performed after the blood pressure measurement (step S2), or a case where the AF determination process (step S5) is performed after the blood pressure measurement (step S2) and the result is determined to be "no AF". Figure 7Among them, only the results of blood pressure measurement (systolic blood pressure SYS, diastolic blood pressure DIA, pulse rate PLS) are displayed, while the determination result of AF is not displayed. It should be noted that in cases where AF determination processing (step S5) is performed after blood pressure measurement (step S2) and it is determined that there is "no AF", Figure 7 the message "no AF" can be displayed on the

[0082] <Examples of AF determination>

[0083] Figure 8 is a diagram showing an example of a plurality of pulse waves for AF determination according to the present embodiment. In the present embodiment, the interval information 362 of the pulse waves obtained in each of multiple blood pressure measurements is integrated, and AF determination is performed based on the integrated interval information 362.

[0084] In Figure 8 when blood pressure measurements are performed three times in a day, in the morning (7:00), at noon (13:00), and in the evening (23:00), the interval information 362 of the pulse waves is obtained in each blood pressure measurement and stored in the storage unit 36. In this case, in the blood pressure measurements in the morning and at noon respectively, the interval information 362 corresponding to each blood pressure measurement is stored in the storage unit 36. When the blood pressure measurement at noon is performed, in Figure 4 step S4 of Figure 4 it is determined by the pulse rate determination unit 232 that the number of pulse waves corresponding to the interval information 362 stored in the storage unit 36 does not reach M required for AF determination (in Figure 4 step S4 of Figure 4 it is no), and the AF determination process is not performed. In the subsequent blood pressure measurement in the evening, the interval information 362 corresponding to this blood pressure measurement is stored in the storage unit 36. When this blood pressure measurement in the evening is performed, in Figure 4 step S4 of Figure 8 it is determined by the pulse rate determination unit 232 that the number of pulse waves corresponding to the interval information 362 stored in the storage unit 36 reaches M required for AF determination (in Figure 4In step S2, the AF determination unit 230 integrates the interval information 362 corresponding to the pulse waves (M pulse waves) obtained in the blood pressure measurements in the morning, noon and evening stored in the storage unit 36, and performs AF determination based on such integrated information ( Figure 4 Step S5). It should be noted that the above-mentioned M pulse waves are composed of one or more blood pressure measurements ( Figure 4 More specifically, the M pulse waves are composed of one or more blood pressure measurements ( Figure 4 The multiple pulse waves obtained in step S2).

[0085] <Advantages of Embodiment>

[0086] AF is a disease that causes serious heart disease and requires treatment to be started as soon as possible. However, many cases are asymptomatic, so people are not aware of AF and the start of treatment is delayed. Therefore, people want to screen for the presence of AF on a daily basis. Such screening is based on electrocardiogram examinations performed by medical institutions, etc., and the opportunities for discovering AF are limited. In contrast, the home sphygmomanometer 20 of the present embodiment can take advantage of the opportunity of the user to measure blood pressure and use the pulse wave obtained in the blood pressure measurement to screen (determine) AF, thereby providing many opportunities for discovering AF. Among patients with AF, symptoms of AF do not always appear, and there are also cases where symptoms appear due to environmental factors such as drinking, stress, and lack of sleep. Therefore, as in the present embodiment, a mechanism that provides many opportunities for discovering AF can also provide supporting information for effectively determining the start of treatment in such cases.

[0087] In addition, the sphygmomanometer 20 of the present embodiment is configured to perform AF determination processing when it is determined that the total number of pulse waves corresponding to the interval information 362 has reached a predetermined number. This configuration eliminates the need to perform three consecutive measurements each time the blood pressure is measured, as in Patent Document 1. Thus, according to the present embodiment, the user is not burdened with the time required for measurement becoming longer, and the measurement site being repeatedly pressed with a predetermined pressure Cp higher than the systolic blood pressure.

[0088] Furthermore, in the present embodiment, unlike Patent Document 1, even if three consecutive blood pressure measurements are not required, the selection unit 231 can remove information related to old past measurement dates and times or pulse waves with insufficient amplitude from the interval information 362 used for AF determination, thereby preventing such information from affecting the determination as noise, and improving the determination accuracy.

[0089] Furthermore, in the present embodiment, only the pulse wave interval information 362 is stored in the storage unit 36 ​​for AF determination, not the pulse wave information itself. Therefore, the memory capacity for storing information required for determination can be saved.

[0090] <Other Implementation Methods>

[0091] (1) In the above embodiment, a program is provided that causes a computer such as the processor 30 of the sphygmomanometer 20 to execute the processing described in the above flowchart. Such a program may also be recorded in a non-temporary computer-readable recording medium such as a floppy disk, a CD-ROM (Compact Disc Read Only Memory), a secondary storage device, a main storage device, and a memory card 29A attached to the computer and provided as a program product. Alternatively, such a program may be recorded in a recording medium such as a HDD 35 built into the computer and provided. In addition, the program may be provided to such a computer by downloading it from a distribution server not shown in the figure via the network 10, 15.

[0092] (2) The configurations described as examples in the above embodiments are examples of the configurations of the present invention, and can be combined with other known technologies, or can be modified by omitting a portion of the configurations without departing from the gist of the present invention. In addition, in the above embodiments, the processes and configurations described in other embodiments can be appropriately adopted for implementation.

[0093] [Note]

[0094] As described above, the present embodiment includes the following disclosures.

[0095] (Composition 1)

[0096] A sphygmomanometer (20), comprising:

[0097] a cuff pressure adjustment unit (23, 24) for increasing or decreasing the cuff pressure indicating the internal pressure of the cuff worn on the measurement site of the user;

[0098] A cuff pressure detection unit (22) detects a cuff pressure signal indicating the cuff pressure;

[0099] a blood pressure measuring unit (220) for measuring the blood pressure of the user based on a pulse wave signal superimposed on a cuff pressure signal detected during the process of increasing or decreasing the cuff pressure;

[0100] an information acquisition unit (221) for acquiring, each time blood pressure is measured, pulse wave characteristic information representing a characteristic amount of the pulse wave from the pulse wave signal superimposed on the cuff pressure signal detected in the blood pressure measurement;

[0101] A storage unit (36) for storing the acquired pulse wave characteristic information of each blood pressure measurement;

[0102] a pulse rate determination unit (232) for determining the number of pulse waves having a characteristic value indicated by the pulse wave characteristic information for each blood pressure measurement; and

[0103] An atrial fibrillation determination unit (230) determines atrial fibrillation in the pulse wave based on the pulse wave characteristic information stored in the storage unit when the total number of the pulse waves in each blood pressure measurement reaches a predetermined number.

[0104] (Composition 2)

[0105] The sphygmomanometer (20) according to configuration 1, wherein:

[0106] The pulse rate determination unit (232) extracts the pulse wave characteristic information corresponding to the blood pressure measurement for which the elapsed time from the blood pressure measurement is greater than a threshold value from the pulse wave characteristic information of each blood pressure measurement, and determines the number of pulse waves of each blood pressure measurement.

[0107] (Composition 3)

[0108] The sphygmomanometer (20) according to configuration 1 or 2, wherein:

[0109] The pulse wave feature quantity represented by the pulse wave feature information includes an interval of the pulse wave represented by the pulse wave signal superimposed on the cuff pressure signal detected in the blood pressure measurement.

[0110] (Composition 4)

[0111] The sphygmomanometer (20) according to Configuration 3, wherein:

[0112] The pulse wave interval includes a time interval between the maximum amplitudes of adjacent pulse waves.

[0113] (Composition 5)

[0114] A sphygmomanometer (20) according to any one of Configurations 1 to 4, wherein:

[0115] The pulse rate determination unit determines the number of pulse waves for each blood pressure measurement by excluding pulse wave characteristic information corresponding to a pulse wave having an amplitude of a characteristic amount represented by the pulse wave characteristic information for each blood pressure measurement that is less than a threshold value.

[0116] (Composition 6)

[0117] The sphygmomanometer (20) according to any one of Configurations 1 to 5, wherein:

[0118] The pulse rate determination unit further determines whether the total number of pulse wave numbers corresponding to the pulse wave characteristic information of each blood pressure measurement in the storage unit has reached the predetermined number.

[0119] The embodiments disclosed this time should be considered in all respects as illustrative and non-restrictive. The scope of the present invention is indicated by the claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0120] Description of Reference Numerals

[0121] 1: network system; 10, 15: network; 10A, 10B: terminal; 20, 20A, 20B, 20C: blood pressure meter; 21: cuff; 22: pressure sensor; 23: pump; 24: valve; 25: A / D conversion circuit; 26: pump drive circuit; 27: valve drive circuit; 28: communication interface; 29: reader / writer; 29A: memory card; 30: processor; 31: display; 31A: display control circuit; 32: operation unit; 32A: measurement switch; 3 3: memory; 34: power supply; 35: HDD; 36: storage unit; 40: server; 42: database; 220: blood pressure measurement unit; 221: interval calculation unit; 230: AF determination unit; 231: selection unit; 232: pulse rate determination unit; 240: output control unit; 250: storage control unit; 311: message; 361: storage area for operation; 362: interval information; 363: blood pressure measurement information; 364: determination information; Cp: specified pressure.

Claims

1. A sphygmomanometer, comprising: a cuff pressure adjustment unit that increases or decreases a cuff pressure indicating an internal pressure of a cuff worn on a measurement site of a user; a cuff pressure detection unit, detecting a cuff pressure signal indicating the cuff pressure; a blood pressure measuring unit that measures the blood pressure of the user based on a pulse wave signal superimposed on a cuff pressure signal detected during the process of increasing or decreasing the cuff pressure; an information acquisition unit that acquires pulse wave characteristic information indicating a characteristic amount of the pulse wave from the pulse wave signal superimposed on the cuff pressure signal detected in the blood pressure measurement each time the blood pressure is measured; A storage unit for storing the acquired pulse wave characteristic information of each blood pressure measurement; a pulse rate determination unit that determines the number of pulse waves having a characteristic amount represented by the pulse wave characteristic information for each blood pressure measurement; as well as The atrial fibrillation determination unit determines atrial fibrillation in the pulse wave based on the pulse wave characteristic information in the storage unit when the total number of the pulse waves in each blood pressure measurement reaches a predetermined number.

2. The sphygmomanometer according to claim 1, wherein: The pulse rate determination unit determines the number of pulse waves in each blood pressure measurement by excluding pulse wave characteristic information corresponding to a blood pressure measurement for which an elapsed time from the blood pressure measurement is greater than a threshold value, from the pulse wave characteristic information in each blood pressure measurement.

3. The sphygmomanometer according to claim 1 or 2, wherein: The pulse wave feature quantity represented by the pulse wave feature information includes an interval of the pulse wave represented by the pulse wave signal superimposed on the cuff pressure signal detected in the blood pressure measurement.

4. The sphygmomanometer according to claim 3, wherein: The pulse wave interval includes a time interval between the maximum amplitudes of adjacent pulse waves.

5. The sphygmomanometer according to claim 4, wherein: The pulse rate determination unit determines the number of pulse waves for each blood pressure measurement by excluding pulse wave characteristic information corresponding to a pulse wave having an amplitude of a characteristic amount represented by the pulse wave characteristic information for each blood pressure measurement that is less than a threshold value.

6. The sphygmomanometer according to claim 5, wherein: The pulse rate determination unit further determines whether the total number of pulse wave numbers corresponding to the pulse wave characteristic information of each blood pressure measurement in the storage unit has reached the predetermined number.

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