Electronic blood pressure monitors, and methods for determining atrial fibrillation in electronic blood pressure monitors.

Abstract

The electronic blood pressure monitor of the present invention includes: a cuff pressure control unit for controlling the pressure of the cuff to be increased or decreased; a pressure detection unit for detecting the cuff pressure signal; and a blood pressure measurement unit for extracting a pulse wave signal representing a pulse wave that overlaps with the cuff pressure signal and measuring blood pressure based on the pulse wave signal. A pulse wave interval calculation unit calculates a set of data representing the pulse wave interval for each measurement opportunity of a subject, based on the pulse wave signal obtained only in one inflation or deflation process (S102). A determination unit aggregates the data sets from three or more measurement opportunities for the subject, calculates the average pulse wave interval, and determines whether there is a possibility of atrial fibrillation based on whether there are irregular pulse wave data in the aggregated data sets that exceed a preset allowable range relative to the average value (S104).

Description

Technical Field

[0001] This invention relates to electronic blood pressure monitors, and more specifically, to an electronic blood pressure monitor capable of determining the possibility of atrial fibrillation. Furthermore, this invention relates to a method for determining the possibility of atrial fibrillation in an electronic blood pressure monitor. Background Technology

[0002] Previously, electronic blood pressure monitors intended for home use included those equipped with a function to determine the likelihood of atrial fibrillation based on acquired pulse wave information (e.g., the Omron Healthcare M7 Intelli IT automatic electronic blood pressure monitor). For example, a subject uses such a blood pressure monitor to take multiple (e.g., three) blood pressure measurements consecutively within a single measurement session. The interval between the pulse wave signals acquired in each measurement, known as the pulse wave interval, is calculated and compared to the average pulse wave interval across the measurements. Pulse wave intervals exceeding a preset tolerance value, such as ±25%, are then classified as irregular pulse waves, and the number of occurrences of these irregular pulse waves is counted. Based on the number of measurements in which irregular pulse waves occur more than a predetermined number across multiple consecutive blood pressure measurements, the likelihood of atrial fibrillation is determined.

[0003] For example, non-patent literature 1 (M. Ishizawa et al. “Development of a Novel Algorithm to Detect Atrial Fibrillation Using an Automated Blood Pressure Monitor With an Irregular Heartbeat Detector”, Circulation Journal, Japan Society of Circulatory Incorporated Associations, September 2019, Vol. 83, No. 12, pp. 2416-2417) reported the following results: In three consecutive blood pressure measurements, the presence of more than two measurements showing an irregular pulse wave was considered a possible indication of atrial fibrillation. In this result, the sensitivity (the proportion of patients accurately diagnosed with atrial fibrillation) was 95.5%, and the specificity (the proportion of patients not diagnosed with atrial fibrillation) was 96.5%, demonstrating very high accuracy.

[0004] Existing technical documents

[0005] Non-patent literature

[0006] Non-patent literature 1: M. Ishizawa et al., “Development of a Novel Algorithm to Detect Atrial Fibrillation Using an Automated Blood Pressure Monitor With an Irregular Heartbeat Detector”, Circulation Journal, Japan Circulatory Society, September 2019, Vol. 83, No. 12, pp. 2416-2417. Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] Typically, the pulse count obtained during a single blood pressure measurement is around 10 beats. Therefore, it is considered that screening for atrial fibrillation based solely on the pulse count obtained from a single blood pressure measurement is not a reliable method.

[0009] However, performing three blood pressure measurements at each testing opportunity is quite inconvenient for the person being tested, due to the increased total time required for each measurement and the feeling of repeated pressure from the cuff above systolic blood pressure. For example, a typical blood pressure measurement takes about 40 to 60 seconds. Furthermore, it is recommended to allow a 30-second to 1-minute interval between measurements. Therefore, to perform three consecutive blood pressure measurements, such as… Figure 14 As shown, a total time of at least 180 seconds is required (40 seconds for the first measurement + 30 seconds for the interval + 40 seconds for the second measurement + 30 seconds for the interval + 40 seconds for the third measurement).

[0010] Therefore, the objective of this invention is to provide an electronic blood pressure monitor capable of accurately determining the possibility of atrial fibrillation in a relatively short time for each measurement opportunity, and a method for determining atrial fibrillation in the electronic blood pressure monitor.

[0011] Technical means to solve the problem

[0012] To address the aforementioned problem, the electronic blood pressure monitor of the present invention measures blood pressure based on the pulse wave of the artery at the site of measurement, characterized in that...

[0013] have:

[0014] The cuff pressure control unit controls the pressure of the cuff worn on the measurement site by applying pressure or depressurizing it.

[0015] The pressure detection unit detects a cuff pressure signal, representing the pressure of the cuff, during the pressurization or depressurization process based on the cuff pressure control unit.

[0016] The blood pressure measuring unit extracts a pulse wave signal that overlaps with the cuff pressure signal, representing a pulse wave, and measures blood pressure based on this pulse wave signal;

[0017] The pulse wave interval calculation unit, for each measurement opportunity of a given subject, calculates a set of data representing the pulse wave interval based on the pulse wave signal obtained only during one inflation or depressurization process; and

[0018] The determination unit aggregates the data sets from three or more testing opportunities for the subject, calculates the average value of the pulse wave intervals, and determines the possibility of atrial fibrillation based on whether there are any irregular pulse wave data in the aggregated data sets that exceed the preset allowable range relative to the average value.

[0019] The time interval between the three measurement opportunities is within a pre-set allowable period.

[0020] "A measurement opportunity" refers to an opportunity for the subject to temporarily wear the cuff for blood pressure measurement. In this invention, a blood pressure measurement is scheduled for each measurement opportunity.

[0021] "Only one pressurization or one depressurization process" means that only one blood pressure measurement is taken at each measurement opportunity. The number of data points included in a dataset is typically assumed to be around ten.

[0022] As for "three testing opportunities", for example, it can be assumed that there are three testing opportunities such as once in the morning, once during the day, and once in the evening of a certain day, or once in the morning of a certain day, once in the morning of the second day, and once in the morning of the third day, etc.

[0023] "Pulse wave interval" refers to the interval between peak values ​​of a pulse wave (or the interval between trough values).

[0024] "Irregular pulse wave" refers to a pulse wave whose intervals exceed a preset tolerance range relative to the average value. "Preset tolerance range" means, for example, within ±25% of the average value. Additionally, "preset tolerance period" means, for example, "one day".

[0025] In the electronic blood pressure monitor of the present invention, blood pressure is measured based on the pulse wave of the artery passing through the measurement site in the following manner: First, the subject wears a cuff on the measurement site and waits for a measurement opportunity. A cuff pressure control unit controls the pressure of the cuff worn on the measurement site during either the inflation or deflation process. During the inflation or deflation process based on the cuff pressure control unit, a pressure detection unit detects a cuff pressure signal representing the cuff pressure. A blood pressure measurement unit extracts a pulse wave signal representing the pulse wave that overlaps with the cuff pressure signal, and measures blood pressure based on this pulse wave signal. Thus, a blood pressure measurement is performed once for each measurement opportunity.

[0026] Here, the pulse wave interval calculation unit calculates a set of data representing the pulse wave interval for each measurement opportunity of a subject, based on the pulse wave signal obtained only in one inflation or deflation process. The number of data points in a set is typically assumed to be around ten. As mentioned above, it is considered that with around ten data points, it is impossible to accurately determine the possibility of atrial fibrillation. Therefore, in this electronic blood pressure monitor, the determination unit aggregates the data sets for three or more measurement opportunities of the subject, calculates the average value of the pulse wave interval, and determines the possibility of atrial fibrillation based on whether there are irregular pulse wave data points in the aggregated data sets that exceed a preset tolerance range relative to the average value. In this case, the number of data points used as the basis for the determination is the same as or greater than the number of data points from three consecutive blood pressure measurements in conventional methods (referring to the method of performing three consecutive blood pressure measurements for each measurement opportunity as described in Non-Patent Document 1, hereinafter the same). Therefore, according to this electronic blood pressure monitor, it is possible to accurately determine the possibility of atrial fibrillation. In particular, in this electronic blood pressure monitor, since the time interval between the three measurement opportunities is within a preset allowable period, the reliability of the determination can be improved.

[0027] Furthermore, in this electronic blood pressure monitor, it is sufficient to perform one blood pressure measurement at each measurement session to determine the possibility of atrial fibrillation; therefore, the time required for each measurement session is relatively short. Alternatively, multiple blood pressure measurements can be performed at each measurement session.

[0028] In one embodiment of the electronic blood pressure monitor, the characteristic is that,

[0029] The determination unit is configured as follows:

[0030] For each set of data from each measurement opportunity, the average value of the pulse wave interval is calculated, and it is determined whether there is data indicating an irregular pulse wave in the set of data. For each measurement opportunity, an individual determination result indicating whether an irregular pulse wave occurred is obtained.

[0031] If an individual determination result showing the occurrence of the irregular pulse wave is obtained in two or more of the three measurement opportunities, it is determined that there is a possibility of atrial fibrillation.

[0032] In this embodiment of the electronic blood pressure monitor, the determination unit calculates the average value of the pulse wave interval for each set of data from each measurement opportunity, and determines whether irregular pulse waves exist in the data set. For each measurement opportunity, it calculates an individual determination result regarding whether an irregular pulse wave has occurred. Furthermore, if an individual determination result indicating the occurrence of an irregular pulse wave is obtained in two or more of the three measurement opportunities, the determination unit determines that there is a possibility of atrial fibrillation. Thus, the possibility of atrial fibrillation can be determined using a simple algorithm.

[0033] In one embodiment of the electronic blood pressure monitor, the characteristic is that,

[0034] The electronic blood pressure monitor has a storage unit that stores the individual judgment result of each measurement opportunity in a corresponding manner with the measurement date and time.

[0035] The determination unit backtracks from the latest result and searches the individual determination results stored in the storage unit. As long as the condition that the time interval between the measurement opportunities is within the allowable period is met and the individual determination results for more than three measurement opportunities are met, it determines whether there is a possibility of atrial fibrillation.

[0036] In this embodiment of the electronic blood pressure monitor, the storage unit stores the individual determination results of each measurement opportunity in a corresponding manner with the measurement date and time. The determination unit backtracks from the latest result and searches the individual determination results stored in the storage unit. If the condition that the time interval between measurement opportunities is within the allowable period is met, and the individual determination results for three or more measurement opportunities are found, it determines whether there is a possibility of atrial fibrillation. Conversely, older individual determination results where the time interval between measurement opportunities exceeds the allowable period are not used as the basis for the determination unit's decision. Therefore, the reliability of the determination can be improved.

[0037] In one embodiment of the electronic blood pressure monitor, the characteristic is that,

[0038] The electronic blood pressure monitor has a normal blood pressure measurement mode and an atrial fibrillation screening mode. In the normal blood pressure measurement mode, the cuff pressure control unit, the pressure detection unit, and the blood pressure measurement unit perform only one blood pressure measurement per measurement opportunity. In the atrial fibrillation screening mode, the cuff pressure control unit, the pressure detection unit, and the blood pressure measurement unit perform more than three blood pressure measurements per measurement opportunity.

[0039] In the normal blood pressure measurement mode, the determination unit determines whether the irregular pulse wave data in the totaled data set representing the pulse wave intervals meets a preset frequency condition.

[0040] The electronic blood pressure monitor has a notification unit that, when the frequent occurrence condition is met, prompts the user to switch from the normal blood pressure measurement mode to the atrial fibrillation screening mode.

[0041] Examples of "pre-set frequent occurrence conditions" include the following:

[0042] i) The condition that there is more than one irregular pulse wave in each of the data sets representing pulse wave intervals of the two most recent measurement opportunities;

[0043] ii) The condition that in more than half of the data sets representing pulse wave intervals for the most recent five measurement opportunities (i.e., for data sets with more than three measurement opportunities), there is more than one irregular pulse wave.

[0044] iii) In the most recent two sets of data representing pulse wave intervals for the same time period each day (morning, daytime, evening, etc.), there are data for more than one irregular pulse wave.

[0045] iv) In more than half of the data sets representing pulse wave intervals at the latest five measurement opportunities for the same time period of the day (morning, daytime, evening, etc.) (i.e., in data sets with more than three measurement opportunities), there is a condition that there is more than one irregular pulse wave.

[0046] In this embodiment of the electronic blood pressure monitor, the default mode is the normal blood pressure measurement mode. In this mode, the cuff pressure control unit, the pressure detection unit, and the blood pressure measurement unit perform only one blood pressure measurement per measurement opportunity. In this normal blood pressure measurement mode, the determination unit determines whether the irregular pulse wave data in the aggregated data set representing the pulse wave intervals meets a preset frequency condition. When the frequency condition is met, the notification unit prompts the user to switch from the normal blood pressure measurement mode to the atrial fibrillation screening mode. This notification prompts the user (including the person being tested, doctors, nurses, and other medical personnel; hereinafter the same) to switch from the normal blood pressure measurement mode to the atrial fibrillation screening mode. If switched to the atrial fibrillation screening mode, atrial fibrillation screening can be performed with higher accuracy compared to the normal blood pressure measurement mode.

[0047] In one embodiment of the electronic blood pressure monitor, the characteristic is that,

[0048] The electronic blood pressure monitor has a normal blood pressure measurement mode and an atrial fibrillation screening mode. In the normal blood pressure measurement mode, the cuff pressure control unit, the pressure detection unit, and the blood pressure measurement unit perform only one blood pressure measurement per measurement opportunity. In the atrial fibrillation screening mode, the cuff pressure control unit, the pressure detection unit, and the blood pressure measurement unit perform more than three blood pressure measurements per measurement opportunity.

[0049] In the normal blood pressure measurement mode, the determination unit determines whether the irregular pulse wave data in the totaled data set representing the pulse wave intervals meets a preset frequency condition.

[0050] The electronic blood pressure monitor has a mode control unit, which controls the switching from the normal blood pressure measurement mode to the atrial fibrillation screening mode when the frequent occurrence condition is met.

[0051] In this embodiment of the electronic blood pressure monitor, a default mode is the normal blood pressure measurement mode. In this mode, the cuff pressure control unit, the pressure detection unit, and the blood pressure measurement unit perform only one blood pressure measurement per measurement opportunity. In this normal blood pressure measurement mode, the determination unit determines whether the irregular pulse wave data in the aggregated data set representing the pulse wave intervals meets a preset frequency condition. When the frequency condition is met, the mode control unit controls the switching from the normal blood pressure measurement mode to the atrial fibrillation screening mode. In the atrial fibrillation screening mode, blood pressure measurements are performed more than three times per measurement opportunity. Therefore, compared to the normal blood pressure measurement mode, the atrial fibrillation screening mode allows for a more accurate determination of the possibility of atrial fibrillation.

[0052] In a second aspect, the present invention provides a method for determining atrial fibrillation in an electronic blood pressure monitor, the electronic blood pressure monitor measuring blood pressure based on the pulse wave of the artery at the measurement site, characterized in that...

[0053] The electronic blood pressure monitor has the following features:

[0054] The cuff pressure control unit controls the pressure of the cuff worn on the measurement site by applying pressure or depressurizing it.

[0055] The pressure detection unit detects a cuff pressure signal, representing the pressure of the cuff, during the pressurization or depressurization process based on the cuff pressure control unit; and

[0056] The blood pressure measuring unit extracts a pulse wave signal that overlaps with the cuff pressure signal, representing a pulse wave, and measures blood pressure based on this pulse wave signal;

[0057] In the aforementioned method for determining atrial fibrillation,

[0058] For each measurement opportunity for a given subject, a set of data representing the pulse wave interval is determined based on the pulse wave signal obtained only in one pressurization process or one depressurization process;

[0059] The data sets from three or more testing opportunities for the subject are aggregated to calculate the average pulse wave interval. Based on whether any irregular pulse waves exceeding a predetermined tolerance range relative to the average exist in the aggregated data sets, a possibility of atrial fibrillation is determined.

[0060] The time interval between the three measurement opportunities is within a pre-set allowable period.

[0061] The atrial fibrillation determination method in the electronic blood pressure monitor according to the present invention can accurately determine whether there is a possibility of atrial fibrillation. In particular, in this electronic blood pressure monitor, since the time interval between the three measurement opportunities is within a pre-set allowable period, the reliability of the determination is improved. Furthermore, to determine whether there is a possibility of atrial fibrillation, only one blood pressure measurement is required for each measurement opportunity; therefore, the time required for each measurement opportunity is relatively short.

[0062] In a third aspect, the electronic blood pressure monitor of the present invention measures blood pressure based on the pulse wave of the artery at the site of measurement, characterized in that...

[0063] have:

[0064] The cuff pressure control unit controls the pressure of the cuff worn on the measurement site by applying pressure or depressurizing it.

[0065] The pressure detection unit detects a cuff pressure signal, representing the pressure of the cuff, during the pressurization or depressurization process based on the cuff pressure control unit.

[0066] The blood pressure measuring unit extracts a pulse wave signal that overlaps with the cuff pressure signal, representing a pulse wave, and measures blood pressure based on this pulse wave signal;

[0067] The pulse wave interval calculation unit, for each measurement opportunity of a given subject, calculates a set of data representing the pulse wave interval based on the pulse wave signal obtained only during one inflation or depressurization process; and

[0068] The determination unit aggregates the data sets from three or more testing opportunities for the subject, calculates the average value of the pulse wave intervals, and determines the possibility of atrial fibrillation based on whether there are any irregular pulse wave data in the aggregated data sets that exceed the preset allowable range relative to the average value.

[0069] The electronic blood pressure monitor has a normal blood pressure measurement mode and an atrial fibrillation screening mode. In the normal blood pressure measurement mode, the cuff pressure control unit, the pressure detection unit, and the blood pressure measurement unit perform only one blood pressure measurement per measurement opportunity. In the atrial fibrillation screening mode, the cuff pressure control unit, the pressure detection unit, and the blood pressure measurement unit perform more than three blood pressure measurements per measurement opportunity.

[0070] In the normal blood pressure measurement mode, the determination unit determines whether the irregular pulse wave data in the totaled data set representing the pulse wave intervals meets a preset frequency condition.

[0071] The electronic blood pressure monitor has a notification unit that, when the frequent occurrence condition is met, prompts the user to switch from the normal blood pressure measurement mode to the atrial fibrillation screening mode.

[0072] In a fourth aspect, the electronic blood pressure monitor of the present invention measures blood pressure based on the pulse wave of an artery at the site of measurement, characterized in that...

[0073] have:

[0074] The cuff pressure control unit controls the pressure of the cuff worn on the measurement site by applying pressure or depressurizing it.

[0075] The pressure detection unit detects a cuff pressure signal, representing the pressure of the cuff, during the pressurization or depressurization process based on the cuff pressure control unit.

[0076] The blood pressure measuring unit extracts a pulse wave signal that overlaps with the cuff pressure signal, representing a pulse wave, and measures blood pressure based on this pulse wave signal;

[0077] The pulse wave interval calculation unit, for each measurement opportunity of a given subject, calculates a set of data representing the pulse wave interval based on the pulse wave signal obtained only during one inflation or depressurization process; and

[0078] The determination unit aggregates the data sets from three or more testing opportunities for the subject, calculates the average value of the pulse wave intervals, and determines the possibility of atrial fibrillation based on whether there are any irregular pulse wave data in the aggregated data sets that exceed the preset allowable range relative to the average value.

[0079] The electronic blood pressure monitor has a normal blood pressure measurement mode and an atrial fibrillation screening mode. In the normal blood pressure measurement mode, the cuff pressure control unit, the pressure detection unit, and the blood pressure measurement unit perform only one blood pressure measurement per measurement opportunity. In the atrial fibrillation screening mode, the cuff pressure control unit, the pressure detection unit, and the blood pressure measurement unit perform more than three blood pressure measurements per measurement opportunity.

[0080] In the normal blood pressure measurement mode, the determination unit determines whether the irregular pulse wave data in the totaled data set representing the pulse wave intervals meets a preset frequency condition.

[0081] The electronic blood pressure monitor has a mode control unit, which controls the switching from the normal blood pressure measurement mode to the atrial fibrillation screening mode when the frequent occurrence condition is met.

[0082] Invention Effects

[0083] As can be seen from the above, the electronic blood pressure monitor and the atrial fibrillation determination method in the electronic blood pressure monitor according to the present invention can determine with high accuracy whether there is a possibility of atrial fibrillation in a relatively short time during each measurement opportunity. Attached Figure Description

[0084] Figure 1 This is a block diagram illustrating the structure of an electronic blood pressure monitor according to one embodiment of the present invention.

[0085] Figure 2 (A) is a diagram showing the process of determining the possibility of atrial fibrillation in the normal blood pressure measurement mode of the above-mentioned electronic blood pressure monitor. Figure 2 (B) indicates that in Figure 2 (A) is a diagram illustrating the process of searching memory for data on the determination object used to determine the possibility of atrial fibrillation.

[0086] Figure 3 (A) is a diagram showing the procedure for blood pressure measurement performed by the aforementioned electronic blood pressure monitor. Figure 3 (B) is a diagram illustrating the standard pulse wave interval. Figure 3 (C) is a diagram illustrating the pulse intervals in which irregular pulse waves occur.

[0087] Figure 4 (A) is an example of the screen displayed when the possibility of atrial fibrillation is determined in the above-mentioned normal blood pressure measurement mode. Figure 4 (B) is a diagram illustrating the screen displayed when there is no possibility of atrial fibrillation (or information related to atrial fibrillation) in the above-described normal blood pressure measurement mode.

[0088] Figure 5 (A) is a graph illustrating the determination of whether a subject (atrial fibrillation patient A) is likely to develop atrial fibrillation based on previous methods of determining the subject data. Figure 5 (B) is a graph illustrating the determination of the subject data and the determination of whether there is a possibility of atrial fibrillation based on the first embodiment of the present invention regarding the subject being tested.

[0089] Figure 6 (A) is a graph illustrating the determination of the subject data and the determination of the possibility of developing atrial fibrillation based on previous methods for another subject (atrial fibrillation patient B). Figure 6 (B) is a diagram illustrating the determination results based on the determination object data of the subject described in the first embodiment above and the determination of whether there is a possibility of atrial fibrillation.

[0090] Figure 7(A) is a graph illustrating the judgment results based on previous methods for judging another subject (healthy subject C) and whether there is a possibility of atrial fibrillation. Figure 7 (B) is a diagram illustrating the determination results based on the determination object data of the subject described in the first embodiment above and the determination of whether there is a possibility of atrial fibrillation.

[0091] Figure 8 This is a diagram illustrating a method for determining whether the judgment data is complete using another judgment object data about the subject being tested (atrial fibrillation patient A).

[0092] Figure 9 (A) is a diagram showing the process of determining whether the data on the irregular pulse wave of the subject meets the preset frequency conditions in the above-mentioned normal blood pressure measurement mode. Figure 9 (B) is a diagram showing another process in the above-mentioned normal blood pressure measurement mode for determining whether the data on the irregular pulse wave of the subject meets the preset frequency conditions.

[0093] Figure 10 This is a diagram illustrating the process of atrial fibrillation screening based on the aforementioned electronic blood pressure monitor.

[0094] Figure 11 (A) is an example of passing through Figure 9 (A) is the image displayed on the monitor when the frequent occurrence condition is met. Figure 11 (B) is an example of passing through Figure 9 (B) is the image displayed on the monitor when the frequent occurrence condition is met.

[0095] Figure 12 This is an example based on a test subject (atrial fibrillation patient A). Figure 9 (A) or Figure 9 (B) is a graph showing the data of the judgment object and the judgment result of whether the frequent occurrence condition is met.

[0096] Figure 13 This is an example based on the above-mentioned subject (atrial fibrillation patient A). Figure 9 (A) or Figure 9 (B) is a graph showing the other judgment object data and the judgment result of whether the frequent occurrence condition is met.

[0097] Figure 14 This graph represents the total time required for each measurement opportunity when determining the likelihood of atrial fibrillation using conventional methods. Detailed Implementation

[0098] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0099] (Structure of a blood pressure monitor)

[0100] Figure 1 The frame structure of an electronic blood pressure monitor 1 according to one embodiment of the present invention is shown. The blood pressure monitor 1 generally includes: a blood pressure measuring cuff 20, which is worn by wrapping around the bar-shaped measuring part (e.g., the upper arm) of the subject; and a body 10, which is equipped with elements for blood pressure measurement.

[0101] The aforementioned cuff 20 is a typical cuff, consisting of a fluid bag 22 sandwiched between a thin, long strip of outer fabric 21 and inner fabric 23, and the periphery of these outer fabrics 21 and inner fabrics 23 is sewn or welded together.

[0102] The main body 10 is equipped with a CPU (Central Processing Unit) 100 as a processor, a display 50, an operation unit 52, a memory 51 as a storage unit, a power supply 53, a pressure sensor 31, an oscillation circuit 310, a pump 32, a pump drive circuit 320, a valve 33, and a valve drive circuit 330. In this example, the air pipe 39a connected to the pressure sensor 31, the air pipe 39b connected to the pump 32, and the air pipe 39c connected to the valve 33 merge into a single air pipe 39, which is connected to the fluid bag 22 inside the cuff 20 in a fluid-flowable manner. Hereinafter, the air pipes 39a, 39b, and 39c mentioned above will be collectively referred to as air pipe 39.

[0103] In this example, the display 50 is composed of an LCD (Liquid Crystal Display) and displays prescribed information according to control signals from the CPU 100. In this example, such as... Figure 4 As illustrated in (B), the display 50, from top to bottom, includes a SYS display area 501 for displaying systolic blood pressure (SYS, mmHg), a DIA display area 502 for displaying diastolic blood pressure (DIA, mmHg), a PLS display area 503 for displaying pulse rate (PLS, beats per minute), and an AF display area 504 for displaying information related to the subject's atrial fibrillation. Furthermore, in Figure 4 In (B), for convenience, dashed boxes are used to illustrate the display areas 501, 502, 503, and 504, but the dashed boxes are not actually displayed. The display 50 may be composed of an organic EL (Electro Luminescence) display or may include LED (Light Emitting Diode).

[0104] In this example, Figure 1 The operation unit 52 shown includes a measurement switch 52A for receiving instructions to start / stop blood pressure measurement, a memory switch 52B for retrieving recorded blood pressure measurement results, and a mode switching switch 52C for receiving instructions to switch between normal blood pressure measurement mode and atrial fibrillation screening mode. The operation signal corresponding to the user's instruction is input to the CPU 100.

[0105] Here, "normal blood pressure measurement mode" refers to a mode in which blood pressure is measured only once per measurement opportunity, and the possibility of atrial fibrillation is determined when all data for the subject is collected. "Atrial fibrillation screening mode" refers to a mode in which blood pressure is measured more than three times per measurement opportunity, and the possibility of atrial fibrillation is determined when all data for the subject is collected.

[0106] The memory 51 stores data for the program used to control the blood pressure monitor 1, setting data for setting various functions of the blood pressure monitor 1, and data on blood pressure measurement results. Additionally, the memory 51 is also used as working memory when the program is executed.

[0107] The CPU 100 controls the overall operation of the blood pressure monitor 1 according to the program stored in the memory 51. The specific control method will be explained later.

[0108] In this example, the pressure sensor 31 is a piezoelectric resistive semiconductor pressure sensor. This pressure sensor 31 outputs the pressure (referred to as "cuff pressure Pc") within the fluid bag 22 of the cuff 20 via the air pipe 39 as a resistance output based on the piezoelectric effect. The oscillation circuit 310 oscillates at an oscillation frequency corresponding to the resistance from the pressure sensor 31. The CPU 100 calculates the cuff pressure Pc based on this oscillation frequency. The pressure sensor 31, the oscillation circuit 310, and the CPU 100 together constitute a pressure detection unit for detecting the pressure of the cuff 20. As described later, the cuff pressure Pc is superimposed with a pressure variation component based on the pulse wave indicated by the measured location (referred to as "pulse wave signal Pm").

[0109] Pump 32 is driven by pump drive circuit 320 based on control signals provided by CPU 100, supplying air to fluid bag 22 built into cuff 20 through air pipe 39. This pressurizes the fluid bag 22 (cuff pressure Pc). Valve 33 is a normally open solenoid valve, opened and closed by valve drive circuit 330 based on control signals provided by CPU 100, to control the cuff pressure Pc by discharging or sealing air into or out of fluid bag 22 through air pipe 39. Pump 32, pump drive circuit 320, valve 33, valve drive circuit 330, and CPU 100 together constitute a cuff pressure control unit for pressurizing or depressurizing cuff pressure Pc.

[0110] The power supply unit 53 supplies power to the CPU 100, display 50, memory 51, pressure sensor 31, pump 32, valve 33, and other components within the main body 10.

[0111] (First Implementation)

[0112] Figure 2 (A) illustrates the procedure for determining the possibility of atrial fibrillation in the normal blood pressure measurement mode of the CPU100 based on the sphygmomanometer 1. This procedure corresponds to the processing of a measurement opportunity for a subject (including one blood pressure measurement). In this example, the measurement opportunities are assumed to be once in the morning (04:00–10:00), once during the day (10:00–19:00), and once in the evening (19:00–02:00).

[0113] When the cuff 20 is worn on the area to be measured, and the subject presses the measuring switch 52A located on the main body 10, Figure 2 (A) Step S101), CPU100 first performs the blood pressure measurement process ( Figure 2 (A) Step S102).

[0114] Specifically, such as Figure 3 As shown in step S1 of (A), the CPU 100 first performs initialization. That is, the CPU 100 initializes the processing memory area and stops the pump 32, and with the valve 33 open, adjusts the pressure sensor 31 to 0 mmHg (setting the atmospheric pressure to 0 mmHg).

[0115] Next, the CPU 100 functions as a pressure control unit, closing valve 33 (step S2), driving pump 32, and initiating pressurization of cuff 20 (step S3). Specifically, the CPU 100 supplies air from pump 32 to the fluid bag 22 embedded in cuff 20 via air piping 39. Simultaneously, the CPU 100 functions as a pressure detection unit, detecting the pressure (cuff pressure Pc) within cuff 20 (fluid bag 22) via air piping 39 using pressure sensor 31, and controlling the pressurization rate based on pump 32 based on cuff pressure Pc. Thus, cuff 20 is pressurized, compressing the artery at the measurement site. Here, the cuff pressure Pc detected by pressure sensor 31 includes not only a smoothly varying component (DC component) but also a pressure variation component based on pulse wave (pulse wave signal Pm).

[0116] Next, when the cuff pressure Pc reaches a preset value (in this example, set to, for example, 200 mmHg, in a manner that sufficiently exceeds the assumed blood pressure value of the subject) (step S4 is "Yes"), the CPU100 stops the pump 32 (step S5).

[0117] Next, the CPU 100 functions as a pressure control unit, slowly opening valve 33 (step S6). This depressurizes the cuff pressure Pc at a substantially constant rate. During this depressurization process, the CPU 100 filters and extracts the pulse wave signal Pm from the cuff pressure Pc. Then, in step S7, the CPU 100 functions as a blood pressure measurement unit, attempting to calculate blood pressure values ​​(systolic blood pressure SYS and diastolic blood pressure DIA) using a known oscillometric method based on the pulse wave signal Pm acquired at this time point. Additionally, the CPU 100 calculates the pulse count PLS [beats per minute] based on the aforementioned pulse wave signal Pm. Furthermore, the CPU 100 functions as a pulse wave interval calculation unit, calculating a set of data representing the pulse wave interval (denoted as "Δt") based on the aforementioned pulse wave signal Pm regarding the current measurement opportunity (in this first embodiment, measurement opportunity is synonymous with measurement frequency). Then, the CPU100 acts as a determination unit, calculates the average value of the pulse wave interval (denoted by "Δtave") for the data set representing the pulse wave interval Δt, and determines whether there is data of irregular pulse waves in the data set.

[0118] In this example, such as Figure 3(B) (A graph representing the pulse wave waveform with time t on the horizontal axis and the pulse wave signal Pm on the vertical axis) As illustrated, the pulse wave interval Δt is defined as the peak-to-peak interval of the pulse wave Pw. An irregular pulse wave is defined as a pulse wave whose average pulse wave interval Δtave exceeds a predetermined tolerance range (±25% in this example). For example, in Figure 3 In the pulse wave Pw1 shown in (C), the interval Δt1 between the preceding pulse wave and the following pulse wave, or the interval Δt2 between the following pulse wave and the average pulse wave interval Δtave, exceeds the allowable range of ±25%. Therefore, the pulse wave Pw1 is determined to be an irregular pulse wave.

[0119] In this example, the CPU100 calculates the number of irregular pulse waves generated in the data set related to the current measurement opportunity (referred to as "irregular pulse wave generation count n") as an individual judgment result. If the irregular pulse wave generation count n is 0, it indicates that no irregular pulse wave was generated for the current measurement opportunity. Conversely, if the irregular pulse wave generation count n is 1 or more, it indicates that an irregular pulse wave was generated for the current measurement opportunity.

[0120] In cases where CPU100 is unable to calculate blood pressure values ​​SYS, DIA, pulse count PLS, and the number of irregular pulse waves n due to insufficient data ( Figure 3 (A) If step S8 is "No", repeat steps S6 to S8 until the calculation is possible.

[0121] If the blood pressure values ​​SYS, DIA, pulse count PLS, and number of irregular pulse waves n can be calculated (step S8 is "yes"), then the CPU100 functions as a pressure control unit, opening valve 33 to control the rapid discharge of air from the cuff 20 (fluid bag 22) (step S9).

[0122] Then, in Figure 3 In step S10 of (A), the CPU 100 controls the display of the blood pressure values ​​SYS, DIA, and pulse count PLS on the display 50. Thus, as... Figure 4 As shown in (B), the SYS display area 501, DIA display area 502, and PLS display area 503 within the display 50 respectively display, for example, systolic blood pressure SYS = 130 mmHg, diastolic blood pressure DIA = 72 mmHg, and pulse rate PLS = 66 beats / minute. Furthermore, in... Figure 3In step S7 of (A), since the possibility of atrial fibrillation has not yet been determined, no information is displayed in the AF display area 504. However, if the number of irregular pulse waves n that occur with respect to the current measurement opportunity is 1 or more, a mark, message, etc. indicating that an "irregular pulse wave" has occurred may be displayed in the AF display area 504.

[0123] Furthermore, in Figure 3 In step S10 of (A), the CPU 100, based on the current measurement opportunity of the subject, controls the storage of the measurement date and time, blood pressure value SYS, DIA, pulse count PLS, and the number of irregular pulse waves n in the memory 51 to establish a corresponding relationship. Thus, as... Figure 5 (B) As illustrated, as a table within memory 51, regarding the current testing opportunity for the aforementioned subject (in this example, atrial fibrillation patient A), in this example, in... Figure 5 In table (B), the first paragraph (the paragraph number directly below the header, and the same applies below) is stored in a corresponding manner, with the measurement date being 09 / 22, the measurement time being 21:17, and the blood pressure values ​​SYS, DIA, and PLS being 130 / 72 / 66, and the number of irregular pulse waves n being 0. Furthermore, the units for the blood pressure values ​​SYS, DIA, and PLS are omitted for simplicity, but as mentioned above, the blood pressure values ​​SYS and DIA are in mmHg, and the pulse count PLS is in beats per minute (the same applies below). In this way, one blood pressure measurement is performed for each measurement opportunity. Then, return... Figure 2 (A) process.

[0124] In addition, in the example above, the blood pressure value, pulse count PLS, and number of irregular pulse waves n were calculated during the decompression of the cuff 20 (fluid bag 22), but it is not limited to this and can also be calculated during the pressurization of the cuff 20 (fluid bag 22).

[0125] Next, in Figure 2 In step S103 of (A), the CPU100 acts as a determination unit, retrospectively searching the individual determination results stored in the memory 51 from the latest measurement (the current measurement opportunity) to determine whether the determination object data is complete.

[0126] Specifically, such as Figure 2 As shown in (B), by going back from the current measurement opportunity, it is determined whether there is data from the previous measurement opportunity within the allowable period (one day in this example). Figure 2(B) In step S131), if there is data (step S131 is "Yes"), then the process further backtracks from the last measurement opportunity to determine if there is data from the previous measurement opportunity within the allowable period (one day in this example) (step S132). If there is no data (step S131 or S132 is "No"), then the processing of this normal blood pressure measurement mode ends.

[0127] For example, current measurement opportunities relative to Figure 5 If there is no data from the previous measurement opportunity (step S131 is "No") in the first segment of (B) (measurement date is 09 / 22, measurement time is 21:17), then the processing of the normal blood pressure measurement mode ends.

[0128] In the next measurement opportunity, with the cuff 20 worn on the measurement site, when the subject presses the measurement switch 52A located on the main body 10 ( Figure 2 (A) Step S101), CPU100 restarts the blood pressure measurement process ( Figure 2 (A) Step S102). Processing of this blood pressure measurement, such as Figure 5 As shown in the second paragraph of (B), the data stored includes the measurement date as 09 / 23, the measurement time as 08:39, the blood pressure values ​​SYS, DIA, and pulse count PLS as 124 / 78 / 76, and the number of irregular pulse waves n as 5. Since there is no data from the measurement two days prior (step S132 is "No"), the processing of this normal blood pressure measurement mode ends.

[0129] Furthermore, in the next measurement opportunity, with the cuff 20 worn on the measurement site, when the subject presses the measurement switch 52A located on the main body 10 ( Figure 2 (A) Step S101), CPU100 restarts the blood pressure measurement process ( Figure 2 (A) Step S102). Processing of this blood pressure measurement, such as Figure 5 As shown in the third paragraph of (B), data such as the measurement date of 09 / 23, the measurement time of 16:14, the blood pressure values ​​SYS, DIA, and pulse count PLS of 117 / 72 / 59, and the number of irregular pulse waves n of 5 are stored. In this measurement opportunity, if the time interval between measurement opportunities is within the aforementioned allowable period, the individual judgment results (data on the number of irregular pulse waves n) for three or more measurement opportunities are collected (D1). Figure 2 (B) Steps S131 and S132 are "Yes"). Therefore, CPU100 determines that the judgment object data D1 is complete. Figure 2(A) Step S103 is "Yes"). In addition, the above-mentioned allowable period is within one day, but can also span multiple days.

[0130] At this point, the CPU100 further functions as a determination unit, determining whether an individual determination result (number of irregular pulse wave occurrences n) has been obtained in two or more of the three measurement opportunities. Figure 2 (A) Step S104). In Figure 5 In example (B), during the first testing opportunity (the previous testing opportunity: testing date 09 / 22, testing time 21:17), no irregular pulse waves were generated (number of irregular pulse waves n = 0). During the second testing opportunity (the previous testing opportunity: testing date 09 / 23, testing time 08:39), an irregular pulse wave was generated (number of irregular pulse waves n = 5). During the third testing opportunity (the current testing opportunity: testing date 09 / 23, testing time 16:14), an irregular pulse wave was generated (number of irregular pulse waves n = 5). In this example, because irregular pulse waves were generated in two out of the three testing opportunities, it was determined that there was a possibility of atrial fibrillation. For ease of understanding, in Figure 5 (B) The rightmost column shows the range of the judgment object data D1 and indicates the judgment result "AF" indicating the possibility of atrial fibrillation. In addition, the judgment result "Non-AF" indicates the possibility of atrial fibrillation.

[0131] Next, the CPU100 will control the display 50 to show information indicating the possibility of atrial fibrillation, in addition to the blood pressure values ​​SYS, DIA, and pulse count PLS related to the current measurement opportunity. In this example, as... Figure 4 As shown in (A), a message such as "Possibility of atrial fibrillation" is displayed in the AF display area 504 of the display 50. In addition, a mark indicating the possibility of atrial fibrillation may be displayed instead of the message or in addition to the message.

[0132] Then, in the next measurement opportunity, with the cuff 20 worn on the measurement site, when the subject presses the measurement switch 52A located on the main body 10 ( Figure 2 (A) Step S101), CPU100 restarts the blood pressure measurement process ( Figure 2 (A) Step S102). Processing of this blood pressure measurement, such as Figure 5As shown in the fourth paragraph of (B), the data stored includes a measurement date of 09 / 23, a measurement time of 21:52, blood pressure values ​​SYS, DIA, and pulse count PLS of 112 / 70 / 61, and the number of irregular pulse waves n of 3. In this case, Figure 2 In step S103 of (A), it is determined that... Figure 5 The judgment data D2 shown in the second to fourth paragraphs of (B) is complete. In this example, since irregular pulse waves were generated in all three of the three measurement opportunities, therefore... Figure 2 In step S104 of (A), it is determined that there is a possibility of atrial fibrillation.

[0133] Similarly, if the subjects are tested repeatedly during the morning, daytime, and evening testing sessions, it is determined whether there is a possibility of atrial fibrillation at each testing session.

[0134] In this case, the amount of data that forms the basis for the aforementioned determination based on CPU 100 is the same as or greater than the amount of data from three consecutive blood pressure measurements in conventional methods. Therefore, based on this blood pressure monitor 1, it is possible to determine with high accuracy whether there is a possibility of atrial fibrillation. Furthermore, it is possible to determine whether there is a possibility of atrial fibrillation using a simple algorithm.

[0135] Furthermore, in this blood pressure monitor 1, to determine the possibility of atrial fibrillation, one blood pressure measurement per measurement session is sufficient, thus requiring a relatively short measurement time per session. Alternatively, multiple blood pressure measurements can be performed per measurement session.

[0136] In addition, Figure 2 In step S103 of (A), even if individual judgment results (data on the number of irregular pulse wave generation times n) are obtained for more than three measurement opportunities, if the time interval between the measurement opportunities deviates from the above-mentioned allowable period ( Figure 2 (B) If step S131 or S132 is "No", then Figure 2 If step S103 of (A) is "No", then CPU 100 does not determine the possibility of atrial fibrillation and ends the processing of the normal blood pressure measurement mode. For example, in Figure 8In the first to third paragraphs of the table, regarding the three testing opportunities for the aforementioned subjects, data D7 was obtained regarding the individual judgment results (number of irregular pulse waves n) of whether an irregular pulse wave was generated. Specifically, no irregular pulse wave was generated in the first testing opportunity (the previous testing opportunity: testing date 09 / 17, testing time 11:10) (number of irregular pulse waves n = 0), no irregular pulse wave was generated in the second testing opportunity (previous testing opportunity: testing date 09 / 20, testing time 08:36) (number of irregular pulse waves n = 0), and an irregular pulse wave was generated in the third testing opportunity (current testing opportunity: testing date 09 / 21, testing time 07:40) (number of irregular pulse waves n = 1). In this example, the period from the third testing opportunity (current testing opportunity) to the second testing opportunity (previous testing opportunity) is less than one day, therefore within the allowable period ( Figure 2 (B) Step S131 is "Yes"). However, the measurement opportunity from the second segment (the last measurement opportunity) to the first segment (the measurement opportunity before that) deviates from the allowable period because the backtracking exceeds two days. Figure 2 (B) Step S132 is "No", therefore Figure 2 (Step S103 of (A) is "No"). Therefore, no determination is made regarding the possibility of atrial fibrillation. Figure 2 (A) step S104). Furthermore, in Figure 8 The rightmost column indicates this situation as "D7: Outside the permitted period".

[0137] In this way, old individual judgment results (data on the number of irregular pulse wave occurrences n) where the time interval between measurement opportunities exceeds the aforementioned allowable period are not used as the basis for the above-mentioned judgment based on CPU100. Therefore, the reliability of the judgment can be improved.

[0138] (Comparison and verification between previous methods and the present invention)

[0139] For example, Figure 5 (A) shows the data from three consecutive blood pressure measurements taken by the subject (in this case, atrial fibrillation patient A) at each measurement opportunity, following the usual procedure. In this example, as... Figure 5As shown in the first to third paragraphs of table (A), three consecutive blood pressure measurements were taken during the 9 PM time slot (evening) on ​​the measurement date of September 22nd. In the blood pressure measurements taken at 9:17 PM, 9:18 PM, and 9:19 PM, the number of irregular pulse waves (n) was 0 in each measurement. Using this data as the judgment target, and following the usual method (where two or more measurements showing irregular pulse waves in three consecutive blood pressure measurements are considered a possibility of atrial fibrillation), the judgment result "Non-AF" was obtained, indicating no possibility of atrial fibrillation. Next, as... Figure 5 As shown in paragraphs four through six of (A), three consecutive blood pressure measurements were taken during the 8:00 AM time slot (morning) on ​​the measurement date of September 23rd. In the measurements taken at 08:39, 08:40, and 08:42, the number of irregular pulse waves (n) were 5, 2, and 7, respectively. Using these as the data for judgment, and following the usual method, a judgment result of "AF" indicating a possibility of atrial fibrillation was obtained. Similarly, below, even regarding... Figure 5 The testing opportunity during the 4 PM time slot (daytime) on September 23rd, as shown in paragraphs 7-9 of (A), also yielded a result indicating a possibility of atrial fibrillation, "AF". Furthermore, even regarding... Figure 5 The testing opportunities during the 9 PM time slot (evening) on ​​September 23rd, as shown in paragraphs 10-12 of (A), also yielded a judgment result of "AF" indicating a possibility of atrial fibrillation. Thus, following conventional methods, since the possibility of atrial fibrillation is determined for each testing opportunity of the subject, even the data from atrial fibrillation patient A depends on the irregular pulse wave pattern at that testing opportunity, resulting in a judgment result categorized as "Non-AF" or "AF". The rationale is that even atrial fibrillation patients do not necessarily experience this symptom frequently; it may only occur temporarily due to environmental factors such as alcohol consumption, stress, and lack of sleep.

[0140] The invention described in the first embodiment uses Figure 5 The data in (B) regarding the blood pressure values ​​SYS, DIA, pulse rate PLS, and number of irregular pulse waves n in patient A with atrial fibrillation are essentially excerpts. Figure 5 (A) contains data from the first blood pressure measurement at each measurement opportunity. Specifically, Figure 5 The data from the first segment (measurement date: 09 / 22, measurement time: 21:17) of the data from the first to third segments of (A) representing the time period from 21:00 on the measurement date 09 / 22 (evening) was used as... Figure 5 The data in the first paragraph of (B). Additionally, Figure 5The data from the fourth segment (measurement date: 09 / 23, measurement time: 08:39) of the 8:00 AM time slot shown in segments four through six of (A) on the measurement date 09 / 23 was used as... Figure 5 The data in the second paragraph of (B). Similarly, the following... Figure 5 The data from the seventh to ninth segments of (A) representing the time period (daytime) from the measurement date 09 / 23 at 16:14 was used as... Figure 5 The data in the third paragraph of (B). Additionally, Figure 5 The data from the tenth segment (measurement date: 09 / 23, measurement time: 21:52) of the data from the 21:00 time period (evening) of the measurement date 09 / 23 shown in segments ten through twelfth in (A) was used as... Figure 5 The data in the fourth segment of (B). As described above, according to the first embodiment described above, after obtaining... Figure 5 In the third segment of (B) (measurement date: 09 / 23, measurement time: 16:14), during the measurement opportunity, the data D1 of the judgment subject was complete, resulting in the judgment result "AF" indicating a possibility of atrial fibrillation. Additionally, after obtaining... Figure 5 In the fourth segment of (B) (measurement date: 09 / 23, measurement time: 21:52), the data for the judgment object D2 was complete, resulting in a judgment result "AF" indicating a possibility of atrial fibrillation. Thus, according to the first embodiment described above, if an individual judgment result indicating the generation of irregular pulse waves is obtained in two or more of the three measurement opportunities, it is determined that there is a possibility of atrial fibrillation. Therefore, compared with the conventional method, the dependence of the irregular pulse wave generation status on a specific measurement opportunity is mitigated, and the result is considered to be a proper (highly accurate) judgment result regarding the possibility of atrial fibrillation.

[0141] Figure 6 (A) shows the data from three consecutive blood pressure measurements taken by another subject (in this case, atrial fibrillation patient B) in the usual manner, at each measurement opportunity. In this example, as Figure 6As shown in the first to third paragraphs of table (A), three consecutive blood pressure measurements were taken during the evening period (7 PM) on the measurement date of September 16th. In the blood pressure measurements taken at 7:32 PM, 7:35 PM, and 7:36 PM, the number of irregular pulse waves (n) were 6, 2, and 3, respectively. Using these as the judgment data, and following the usual method (where two or more measurements showing irregular pulse waves in three consecutive blood pressure measurements are considered a possibility of atrial fibrillation), the judgment result "AF" indicating a possibility of atrial fibrillation was obtained. Next, as... Figure 6 As shown in paragraphs four and five of (A), two consecutive blood pressure measurements were performed during the 6 AM time slot (morning) on ​​the measurement date of September 17th. In the blood pressure measurements taken at 06:08 and 06:11, the number of irregular pulse waves (n) was 3 and 4, respectively. In this case, because the measurement was stopped at the second blood pressure measurement, the data for the subject was not complete in the conventional method, resulting in an "insufficient number of measurements". Next, as... Figure 6 As shown in paragraphs six through eight of (A), three consecutive blood pressure measurements were taken during the 12:00 PM time slot (daytime) on the measurement date of September 17th. In the blood pressure measurements taken at 12:49, 12:50, and 12:51, the number of irregular pulse waves (n) was 2, 4, and 6, respectively. Using these as the data for judgment, and after judgment according to the usual method, a judgment result of "AF" indicating the possibility of atrial fibrillation was obtained. Similarly, even regarding... Figure 6 The testing opportunity during the 7 PM time slot (evening) on ​​September 17th, as shown in paragraphs 9-11 of (A), also yielded a result of "AF" indicating a possibility of atrial fibrillation. Thus, according to conventional methods, if a blood pressure measurement for a given subject is less than three times due to some reason (error in the number of measurements performed on the subject, malfunction of the blood pressure monitor, etc.), it is considered an insufficient number of measurements, and the possibility of atrial fibrillation is not assessed.

[0142] Figure 6 The data shown in (B) regarding the blood pressure values ​​SYS, DIA, pulse rate PLS, and number of irregular pulse waves n of atrial fibrillation patient B are extracted for the purpose of implementing the first embodiment of the present invention. Figure 6 Data from the first blood pressure measurement at each measurement opportunity in (A). Specifically, Figure 6 The data from the first segment (measurement date: 09 / 16, measurement time: 19:32) of the data from the first to third segments of Table (A) for the time period (evening) of the measurement date 09 / 16 was used as... Figure 6(B) The data in the first paragraph of the table. Additionally, Figure 6 The data from the fourth segment (measurement date: 09 / 17, measurement time: 06:08) of the 6:00 AM time slot shown in the fourth and fifth segments of (A) was used as... Figure 6 The data in the second paragraph of (B). Similarly, the following... Figure 6 The data from the sixth segment (measurement date: 09 / 17, measurement time: 12:49) of the data from the 12:00 time period (daytime) on the measurement date of 09 / 17, shown in segments six through eight of (A), was used as... Figure 6 The data in the third paragraph of (B). Additionally, Figure 6 The data from the ninth segment (measurement date: 09 / 17, measurement time: 19:35) of the data from the 19:00 time period (evening) on ​​the measurement date of 09 / 17, as shown in segments nine through eleven of (A), was used as... Figure 6 The data in the fourth segment of (B). According to the first embodiment described above, after obtaining... Figure 6 In the third segment of (B) (measurement date: 09 / 17, measurement time: 12:49), during the measurement opportunity, the data D3 of the judgment subject was complete, resulting in the judgment result "AF" indicating a possibility of atrial fibrillation. Additionally, after obtaining... Figure 6 In the fourth segment of (B) (measurement date: 09 / 17, measurement time: 19:35), the data for the judgment subject D4 was collected, resulting in a judgment result "AF" indicating a possibility of atrial fibrillation. Thus, according to the first embodiment described above, since only one blood pressure measurement is used per measurement opportunity, after the third segment (measurement date: 09 / 17, measurement time: 12:49) where the judgment subject data for atrial fibrillation patient B was collected, a judgment result "AF" indicating a possibility of atrial fibrillation was obtained in every measurement opportunity. Therefore, according to the first embodiment described above, as long as the subject only needs to have one blood pressure measurement performed at each measurement opportunity where the cuff 20 is temporarily worn on the measurement site, it can be said that insufficient measurement counts for each measurement opportunity are unlikely to occur.

[0143] Figure 7 (A) shows the data from three consecutive blood pressure measurements taken by another subject (in this case, healthy subject C) in the usual manner at each measurement opportunity. In this example, as Figure 7As shown in the first to third paragraphs of table (A), three consecutive blood pressure measurements were taken during the 4 AM time slot (morning) on ​​the measurement date of August 1st. The number of irregular pulse waves (n) observed in the measurements at 04:51, 04:52, and 04:53 was 0. Using this data as the judgment criteria, and following the usual method, the judgment result "Non-AF" was obtained, indicating no possibility of atrial fibrillation. Next, as... Figure 7 As shown in paragraphs four through six of (A), three consecutive blood pressure measurements were taken during the 13:00 time slot (daytime) on the measurement date of August 1st. The number of irregular pulse waves (n) observed in the measurements at 13:35, 13:36, and 13:37 was 0. Using this data as the judgment criteria, and following conventional methods, a judgment of "Non-AF" was obtained, indicating no possibility of atrial fibrillation. Similarly, the following applies even to... Figure 7 The testing opportunity during the 10 PM time slot (evening) on ​​August 1st, as shown in paragraphs 7-9 of (A), also yielded a "Non-AF" result indicating no possibility of atrial fibrillation. Furthermore, even for... Figure 7 The testing opportunity at 5 a.m. (morning) on ​​the testing date of 08 / 02, as shown in paragraphs 10 to 12 of (A), also yielded a result of "Non-AF" indicating no possibility of atrial fibrillation. Thus, according to the conventional method, for healthy individual C, every testing opportunity yielded a result of "Non-AF" indicating no possibility of atrial fibrillation.

[0144] Figure 7 (B) shows the blood pressure values ​​SYS, DIA, pulse rate PLS, and number of irregular pulse waves n for healthy individual C, which are extracted for the purpose of implementing the first embodiment of the present invention. Figure 7 (A) contains data from the first blood pressure measurement at each measurement opportunity. Specifically, Figure 7 The data from the first segment (measurement date 08 / 01, measurement time 04:51) of the data in the first to third segments of Table (A) for the 4 AM time period on the measurement date 08 / 01 was used as... Figure 7 (B) The data in the first paragraph of the table. Additionally, Figure 7 The data from the fourth segment (measurement date 08 / 01, measurement time 13:35) of the time period (daytime) shown in segments four through six of (A) on the measurement date 08 / 01 was used as... Figure 7 The data in the second paragraph of (B). Similarly, the following... Figure 7The data from the seventh to ninth segments of (A) representing the time period from 22:00 (evening) on ​​the measurement date of 08 / 01 was used as... Figure 7 The data in the third paragraph of (B). Additionally, Figure 7 The data from the tenth segment (measurement date 08 / 02, measurement time 05:00) of the data from the 5:00 AM time slot (measurement time 05:00) of the measurement date 08 / 02 shown in segments ten through twelfth in (A) was used as... Figure 7 The data in the fourth segment of (B). According to the first embodiment described above, after obtaining... Figure 7 In the third segment of (B) (measurement date: 08 / 01, measurement time: 22:53), during the measurement opportunity, the subject's data D5 was complete, resulting in the judgment result "Non-AF," indicating no possibility of atrial fibrillation. Additionally, after obtaining... Figure 6 In the fourth segment of (B) (measurement date: 08 / 02, measurement time: 05:00), the data for the subject D6 was collected, resulting in a "Non-AF" determination that there was no possibility of atrial fibrillation. Thus, according to the first embodiment described above, for healthy individual C, after collecting the data for the third segment of the subject (measurement date: 08 / 01, measurement time: 22:53), the determination of "Non-AF" indicating no possibility of atrial fibrillation was obtained in every measurement opportunity.

[0145] Thus, from Figure 5 (A) judgment result and Figure 5 (B) Comparison of the judgment results Figure 6 (A) judgment result and Figure 6 (B) Comparison of the judgment results Figure 7 (A) judgment result and Figure 7 The comparison of the determination results in (B) verifies that, according to the first embodiment of the present invention, it is possible to determine with high accuracy whether there is a possibility of atrial fibrillation. Furthermore, from... Figure 6 (A) judgment result and Figure 6 (B) Comparison of the judgment results shows that, in the first embodiment of the present invention, since it is sufficient to perform only one blood pressure measurement in each measurement opportunity when the subject temporarily wears the cuff 20 on the measurement site, it is not easy to have insufficient measurement times for each measurement opportunity.

[0146] The condition that the time interval between the determination opportunities is "within one day" is not a strict numerical value, but rather, for example, within one day after rounding to the decimal point (the same applies below).

[0147] Furthermore, in the example above, the testing opportunities are assumed to be once in the morning (04:00–10:00), once during the day (10:00–19:00), and once in the evening (19:00–02:00), but are not limited to these. For example, such as Figure 8 As shown in paragraphs five through seven of the table, the testing opportunities can also be set to three times: once on the morning of one day, once on the morning of the second day, and once on the morning of the third day. Specifically, Figure 8 The fifth measurement opportunity (measurement date 09 / 23, measurement time 08:39) corresponds to once on a certain day in the morning, and the number of irregular pulse waves generated, n, is 5. The sixth measurement opportunity (measurement date 09 / 24, measurement time 08:16) corresponds to once on the morning of the second day, and the number of irregular pulse waves generated, n, is 2. Furthermore, the seventh measurement opportunity (measurement date 09 / 25, measurement time 08:32) corresponds to once on the morning of the third day, and the number of irregular pulse waves generated, n, is 0. In this example, in the seventh measurement opportunity (measurement date 09 / 25, measurement time 08:32), the data D8 of the judgment subject was complete, resulting in the judgment result "AF" indicating a possibility of atrial fibrillation. Thus, in the first embodiment described above, it can also be assumed that there are three measurement opportunities: once on a certain day in the morning, once on the morning of the second day, and once on the morning of the third day.

[0148] Furthermore, while the example above uses data from three testing opportunities as the judgment data, it is not limited to this. Data from four or more testing opportunities can also be used as the judgment data.

[0149] Additionally, in the example above, in Figure 3 In step S7 of (A), an individual determination result (number of irregular pulse waves n) is obtained for each measurement opportunity where an irregular pulse wave was generated, but this is not limited to this. Alternatively, the data sets representing pulse wave intervals from three or more measurement opportunities for the subject can be aggregated together to calculate the average pulse wave interval, and the possibility of atrial fibrillation can be determined based on whether there are any irregular pulse waves in the aggregated data set that exceed a preset allowable range relative to the average value.

[0150] (Second Implementation)

[0151] Figure 9 (A) illustrates the procedure for determining whether data on irregular pulse waves of the subject meet the pre-selected frequency conditions in the above-described normal blood pressure measurement mode.

[0152] Examples of "pre-set frequent occurrence conditions" include the following:

[0153] i) The condition that there is more than one irregular pulse wave in each of the data sets representing pulse wave intervals of the two most recent measurement opportunities;

[0154] ii) The condition that in more than half of the data sets representing pulse wave intervals for the most recent five measurement opportunities (i.e., for data sets with more than three measurement opportunities), there is more than one irregular pulse wave.

[0155] iii) In the most recent two sets of data representing pulse wave intervals for the same time period each day (morning, daytime, evening, etc.), there are data for more than one irregular pulse wave.

[0156] iv) In more than half of the data sets representing pulse wave intervals at the latest five measurement opportunities for the same time period of the day (morning, daytime, evening, etc.) (i.e., in data sets with more than three measurement opportunities), there is a condition that there is more than one irregular pulse wave.

[0157] Given the frequency conditions i) and iii) above, as the data to be judged, it is necessary to gather individual judgment results (data on the number of irregular pulse wave occurrences n) for two measurement opportunities within the allowable period. Given the frequency conditions ii) and iv) above, as the data to be judged, it is necessary to gather individual judgment results for five measurement opportunities within the allowable period. Thus, based on the pre-set frequency conditions, as the data to be judged, it is determined how many measurement opportunities require the gathering of individual judgment results.

[0158] In the initial example, the frequent occurrence condition was set as i) above: "the condition that there is more than one irregular pulse wave in each of the two most recent measurement opportunities".

[0159] With the cuff 20 worn on the site of measurement, when the subject (in this example, atrial fibrillation patient A) presses the measurement switch 52A located on the main body 10 ( Figure 9 (A) Step S201), CPU100 first performs the blood pressure measurement process ( Figure 9 (A) Step S202). In this step S202, with Figure 2 Similarly, in step S102 of (A), the CPU100 acts as a determination unit and calculates the number of irregular pulse waves generated as an individual determination result in the data set regarding the current measurement opportunity (in this second embodiment, it is limited to the normal blood pressure measurement mode, where measurement opportunity is synonymous with measurement number).

[0160] Here, for example Figure 12The data in the first and second paragraphs of the table has been saved, and the data on the current measurement opportunities has been saved in... Figure 12 The third paragraph of the table. Specifically, in Figure 12 In the first measurement opportunity (the previous measurement opportunity: measurement date 09 / 17, measurement time 11:10), the number of irregular pulse waves generated, n, was 0. In the second measurement opportunity (the previous measurement opportunity: measurement date 09 / 18, measurement time 21:41), the number of irregular pulse waves generated, n, was 1. In the third measurement opportunity (the current measurement opportunity: measurement date 09 / 19, measurement time 17:09), the number of irregular pulse waves generated, n, was 1.

[0161] Next, in Figure 9 In step S203 of (A), the CPU 100 backtracks from the latest measurement opportunity (the current measurement opportunity) and searches for individual judgment results stored in the memory 51 to determine whether the judgment object data is complete. Figure 12 In the examples in the second and third paragraphs, individual judgment results were obtained regarding the two measurement opportunities (data on the number of irregular pulse wave occurrences, n). Therefore, CPU100 determined that the judgment object data D9 was complete. Figure 9 (A) If step S203 is "Yes". In addition, if the data of the determination object is not complete (step S203 is "No"), the process ends and waits for the next measurement opportunity.

[0162] If the data for the aforementioned judgment objects are complete, Figure 9 In step S204 of (A), the CPU100 functions as a determination unit, determining whether the data of the irregular pulse wave meets the preset frequency conditions. Figure 12 In the examples of the second and third paragraphs, in the previous measurement opportunity (measurement date 09 / 18, measurement time 21:41) and the current measurement opportunity (measurement date 09 / 19, measurement time 17:09), the number of irregular pulse waves generated, n, is 1 or more in each of them. Therefore, the CPU100 determines that the condition i) above is satisfied: "In the data set representing the pulse wave interval for the two most recent measurement opportunities, there is data on more than one irregular pulse wave in each of them". Figure 9 (A) Step S204 is "Yes"). For ease of understanding, in Figure 12 The rightmost column shows the range of the data D9 to be judged, and indicates the judgment result of "frequent irregular pulse waves" if the frequent occurrence condition is met. In addition, if the frequent occurrence condition is not met ("No" in step S204), the process ends and waits for the next measurement opportunity.

[0163] Under the condition of frequent occurrence described above, Figure 9In step S205 of (A), the CPU100 functions as a notification unit, prompting a switch from the normal blood pressure measurement mode to the atrial fibrillation screening mode. For example, as... Figure 11 As shown in (A), a message such as "Recommended Atrial Fibrillation Mode Measurement" is displayed in the AF display area 504 of the display 50. This notification prompts users (including the person being tested, doctors, nurses, and other medical personnel) to switch from the normal blood pressure measurement mode to the atrial fibrillation screening mode (described later). If the user switches via mode switch 52C (see...) Figure 1 Switching to atrial fibrillation screening mode allows for more accurate screening of atrial fibrillation compared to the normal blood pressure measurement mode. Additionally, a prompt to switch to atrial fibrillation screening mode can be displayed instead of a message, or in addition to a message.

[0164] Instead, such as Figure 9 As shown in step S205′ of (B), the CPU100 can also function as a mode control unit, controlling the switching from the normal blood pressure measurement mode to the atrial fibrillation screening mode. In this case, for example, as... Figure 11 As shown in (B), the message "Next measurement will be performed in atrial fibrillation mode" is displayed in the AF display area 504 of the display 50. Furthermore, Figure 9 (B) Steps S201 to S204 and Figure 9 (A) Steps S201 to S204 are the same.

[0165] Figure 10 The procedure for the atrial fibrillation screening mode of the CPU100 of the blood pressure monitor 1 is shown. In the atrial fibrillation screening mode, blood pressure measurements are scheduled to be repeated at least three times at each measurement opportunity.

[0166] With the cuff 20 worn on the area to be measured, when the subject presses the measuring switch 52A located on the main body 10 ( Figure 10 In step S301), CPU100 begins processing the atrial fibrillation screening mode.

[0167] In this atrial fibrillation screening mode, the CPU100 first performs the blood pressure measurement process. Figure 10 Step S302). This step S302 is related to... Figure 9 (A) or Figure 9 (B) Step S202 (specifically, Figure 3 (A) Steps S1 to S10 are the same. Therefore, for the current number of measurements in the current measurement opportunity of the subject, the measurement date and time, blood pressure value SYS, DIA, pulse count PLS, and number of irregular pulse waves n are correspondingly established and stored in memory 51.

[0168] Next, as Figure 10 As shown in step S303, the CPU 100 determines whether the blood pressure measurement (step S302) has only been performed a preset number of times (three times in this example). If the blood pressure measurement has not been performed a preset number of times (step S303 is "No"), the process is repeated until the preset number of times is performed. Thus, data on the three consecutive blood pressure measurements for the current measurement opportunity (i.e., the measurement date and time, blood pressure value SYS, DIA, pulse count PLS, and number of irregular pulse waves n) are stored in the memory 51.

[0169] Next, as Figure 10 As shown in step S304, the CPU 100 uses the data from three consecutive blood pressure measurements stored in the memory 51 as the judgment data, and determines, for example, whether there is a possibility of atrial fibrillation using conventional methods. Specifically, if two or more of the three consecutive blood pressure measurements show an irregular pulse wave, it is determined that there is a possibility of atrial fibrillation. If the number of measurements showing an irregular pulse wave is less than one, it is determined that there is no possibility of atrial fibrillation.

[0170] Next, as Figure 10 As shown in step S305, in addition to the blood pressure values ​​SYS, DIA, and pulse count PLS from the last number of measurements, the CPU 100 also displays information indicating the possibility of atrial fibrillation on the display 50. For example, with Figure 4 Similarly, in AF display area 504 of (A), a message such as "Possibility of atrial fibrillation" is displayed. In addition, a marker urging switching to atrial fibrillation screening mode may be displayed instead of the message or in addition to the message.

[0171] In this atrial fibrillation screening mode, blood pressure is measured more than three times during each measurement opportunity. Therefore, compared with the usual blood pressure measurement mode, this atrial fibrillation screening mode can determine the possibility of atrial fibrillation with higher accuracy.

[0172] In addition, Figure 10 In this example, the data set of three consecutive blood pressure measurements taken at the current measurement opportunity is used as the judgment data, but it is not limited to this. Data sets of four or more measurement opportunities can also be used as the judgment data.

[0173] (Variation Example 1)

[0174] As an example of the aforementioned frequent occurrence condition, the condition described in ii) above, "in more than half of the data sets representing pulse wave intervals for the five most recent measurement opportunities (i.e., for data sets with three or more measurement opportunities), there is data on one or more irregular pulse waves," will be explained.

[0175] When attention Figure 12 In the fifth through ninth sections of the table, during the fifth measurement opportunity (measurement date 09 / 21, measurement time 07:40), the number of irregular pulse waves, n, was 1. During the sixth measurement opportunity (measurement date 09 / 22, measurement time 07:50), the number of irregular pulse waves, n, was 0. During the seventh measurement opportunity (measurement date 09 / 23, measurement time 08:39), the number of irregular pulse waves, n, was 5. During the eighth measurement opportunity (measurement date 09 / 24, measurement time 08:16), the number of irregular pulse waves, n, was 2. During the ninth measurement opportunity (current measurement opportunity: measurement date 09 / 25, measurement time 08:32), the number of irregular pulse waves, n, was 0.

[0176] In this case, after obtaining Figure 12 When the CPU100 receives the data for the ninth measurement opportunity (the current measurement opportunity), it determines that the data for the judgment object D10 is complete. Figure 9 (A) Step S203 is "Yes"). Then, in Figure 9 In step S204 of (A), the CPU100 functions as a determination unit, determining whether the data of the irregular pulse wave meets the frequency condition of ii) above. Figure 12 In the examples of segments 5 through 9, in the three measurement opportunities of segment 5 (measurement date 09 / 21, measurement time 07:40), segment 7 (measurement date 09 / 23, measurement time 08:39), and segment 8 (measurement date 09 / 24, measurement time 08:16), the number of irregular pulse waves generated, n, is 1 or more in each of them. Therefore, CPU 100 determines that the condition ii) above is satisfied: "In more than half of the data sets representing pulse wave intervals for the five most recent measurement opportunities (i.e., for data sets with three or more measurement opportunities), there is data on one or more irregular pulse waves." Figure 9 (A) Step S204 is "Yes"). For ease of understanding, in Figure 12 The rightmost column shows the range of the data D10 for the judgment object, and indicates the judgment result "frequent irregular pulse waves" that meets the frequent occurrence condition. Following this judgment, as described above, continue... Figure 9 (A) step S205 or Figure 9 (B) Step S205′ processing.

[0177] (Variation Example 2)

[0178] As an example of the aforementioned frequent occurrence condition, we will explain the condition that "in the data sets representing pulse wave intervals of the two most recent measurement opportunities for the same time period of each day (morning, daytime, evening, etc.), there are more than one irregular pulse wave data respectively".

[0179] Figure 13 The table header indicates the measurement dates 09 / 19, 09 / 20, ..., 09 / 25, and the side of the table indicates the measurement time periods: "Morning (04:00-10:00)," "Daytime (10:00-19:00)," and "Evening (19:00-02:00)." Within each box on the table body, the measurement time is indicated from top to bottom (e.g., 08:07 in the top left box), the blood pressure values ​​SYS, DIA, and pulse count PLS obtained at that time (e.g., 124 / 76 / 62 in the top left box), and the number of irregular pulse waves n (e.g., n=0 in the top left box). In this example, in... Figure 13 In this study, we focus on the daytime measurement opportunities on measurement date 09 / 23 (measurement date 09 / 23, measurement time 16:14) and the daytime measurement opportunities on measurement date 09 / 24 (measurement date 09 / 24, measurement time 15:06). The latter measurement opportunity (measurement date 09 / 24, measurement time 15:06) is set as the current measurement opportunity.

[0180] In this case, upon obtaining the measurement opportunity during the daytime period of the aforementioned measurement date 09 / 24 (measurement date 09 / 24, measurement time 15:06), the CPU100 determines that the judgment object data D11 is complete. Figure 9 (A) Step S203 is "Yes"). Then, in Figure 9 In step S204 of (A), the CPU 100 acts as a determination unit, judging whether the irregular pulse wave data satisfies the frequency condition of iii) above. In the example above, in the daytime measurement opportunities on the measurement date 09 / 23 (measurement date 09 / 23, measurement time 16:14) and the daytime measurement opportunities on the measurement date 09 / 24 (measurement date 09 / 23, measurement time 15:06), the number of irregular pulse waves n is 1 or more in both cases. Therefore, the CPU 100 determines that the condition of iii) above is satisfied: "In the data sets representing pulse wave intervals of the two most recent measurement opportunities for the same time period of each day (morning, daytime, evening, etc.), there is data of more than one irregular pulse wave in each case." Figure 9 (A) Step S204 is "Yes"). For ease of understanding, in Figure 13 The daytime time period column shows the range of the data D11 to be judged, and indicates the judgment result "frequent irregular pulse waves" that meets the frequent occurrence condition. After this judgment, as described above, continue... Figure 9 (A) step S205 or Figure 9 (B) Step S205′ processing.

[0181] (Variation Example 3)

[0182] As an example of the aforementioned frequent occurrence condition, we will explain the condition that, in more than half of the data sets representing pulse wave intervals from the five most recent measurement opportunities for the same time period (morning, daytime, evening, etc.) of each day (i.e., in data sets with more than three measurement opportunities), there is data on more than one irregular pulse wave.

[0183] In this example, Figure 13 In this study, we focus on the testing opportunities during the morning time slots of the following testing dates: September 20th (test date 09 / 20, test time 08:36), September 21st (test date 09 / 21, test time 07:40), September 22nd (test date 09 / 22, test time 07:50), September 23rd (test date 09 / 23, test time 08:39), and September 24th (test date 09 / 24, test time 08:16). The testing opportunity during the morning time slot of September 24th (test date 09 / 24, test time 08:16) is set as the current testing opportunity.

[0184] In this case, upon receiving data from the morning time slot of the aforementioned measurement date 09 / 24 (measurement date 09 / 24, measurement time 08:16), the CPU100 determines that the data D12 of the judgment object is complete (in... Figure 9 (A) Step S203 is "Yes"). Then, in Figure 9In step S204 of (A), the CPU100 acts as a determination unit, determining whether the data of irregular pulse waves satisfies the frequency condition of iv) above. In the example above, in the three measurement opportunities—the morning time period of measurement date 09 / 21 (measurement date 09 / 21, measurement time 07:40), the morning time period of measurement date 09 / 23 (measurement date 09 / 23, measurement time 08:39), and the morning time period of measurement date 09 / 24 (measurement date 09 / 24, measurement time 08:16)—the number of irregular pulse wave occurrences n is 1 or more in each of the three measurement opportunities. Therefore, the CPU100 determines that the condition of iv) above is satisfied: "In more than half of the data sets representing pulse wave intervals in the latest five measurement opportunities for the same time period (morning, daytime, evening, etc.) of each day (i.e., in data sets of three or more measurement opportunities), there is data of one or more irregular pulse waves." Figure 9 (A) Step S204 is "Yes"). For ease of understanding, in Figure 13 The "Morning Time Period" column shows the range of the data D12 to be judged, and indicates the judgment result "Frequent AF" that meets the frequent occurrence condition. Following this judgment, as described above, the process continues... Figure 9 (A) step S205 or Figure 9 (B) Step S205′ processing.

[0185] In addition, the frequency conditions described in i) to iv) above can be used individually or in combination. When used in combination, if any one of the frequency conditions described in i) to iv) above is satisfied during the current measurement opportunity, the CPU 100 determines that the data of the irregular pulse wave satisfies the frequency condition. Figure 9 (Step S204 of (A) is "Yes"). Thus, it is possible to determine with high accuracy whether irregular pulse waves occur frequently.

[0186] Furthermore, the "pre-set frequency condition" in this second embodiment can also be a condition as described in the first embodiment above, in which irregular pulse waves are generated in two or more of the three measurement opportunities during each measurement opportunity (the number of irregular pulse wave generation times n is 1 or more). In other words, it is a condition in itself that the data representing the pulse wave interval exists in the data set of two or more of the three measurement opportunities.

[0187] In the example above, the measurement site is set as the upper arm, but it is not limited to this. The measurement site can be the upper limb other than the upper arm, such as the wrist, or it can be the lower limb, such as the ankle.

[0188] In the above example, the atrial fibrillation determination method of the present invention is applicable to blood pressure monitors that measure blood pressure using the oscillometric method. However, it is not limited thereto, and the atrial fibrillation determination method based on the present invention can also be applied to various types of electronic blood pressure monitors, such as blood pressure monitors that measure blood pressure using the tension measurement method (pressing on the skin to partially flatten the blood vessels and continuously measuring blood pressure for each beat based on the pulse wave signal), etc.

[0189] The above embodiments are merely illustrative, and various modifications can be made without departing from the scope of the present invention. The multiple embodiments described can be implemented independently or combined with each other. Furthermore, features in different embodiments can be implemented independently or combined with each other.

[0190] Explanation of reference numerals in the attached figures:

[0191] 1. Blood pressure monitor

[0192] 10 main body

[0193] 20. Blood pressure measurement cuff

[0194] 31 Pressure Sensor

[0195] 50 monitors

[0196] 51 Memory

[0197] 52 Operations Department

[0198] 100 CPU

Claims

1. An electronic blood pressure monitor, based on measuring blood pressure through the pulse wave of an artery at the site of measurement, characterized in that, have: The cuff pressure control unit controls the pressure of the cuff worn on the measurement site by applying pressure or depressurizing it. The pressure detection unit detects a cuff pressure signal, representing the pressure of the cuff, during the pressurization or depressurization process based on the cuff pressure control unit. The blood pressure measuring unit extracts a pulse wave signal that overlaps with the cuff pressure signal, representing a pulse wave, and measures blood pressure based on this pulse wave signal; The pulse wave interval calculation unit, for each measurement opportunity of a given subject, calculates a set of data representing the pulse wave interval based on the pulse wave signal obtained only during one inflation or depressurization process; and The determination unit aggregates the data sets from three or more testing opportunities for the subject, calculates the average value of the pulse wave intervals, and determines the possibility of atrial fibrillation based on whether there are any irregular pulse wave data in the aggregated data sets that exceed the preset allowable range relative to the average value. The electronic blood pressure monitor has a normal blood pressure measurement mode and an atrial fibrillation screening mode. In the normal blood pressure measurement mode, the cuff pressure control unit, the pressure detection unit, and the blood pressure measurement unit perform only one blood pressure measurement per measurement opportunity. In the atrial fibrillation screening mode, the cuff pressure control unit, the pressure detection unit, and the blood pressure measurement unit perform more than three blood pressure measurements per measurement opportunity. In the normal blood pressure measurement mode, the determination unit determines whether the irregular pulse wave data in the totaled data set representing the pulse wave intervals meets a preset frequency condition. The electronic blood pressure monitor has a notification unit that, when the frequent occurrence condition is met, prompts the user to switch from the normal blood pressure measurement mode to the atrial fibrillation screening mode.

2. The electronic blood pressure monitor as described in claim 1, characterized in that, The determination unit is configured as follows: For each set of data from each measurement opportunity, the average value of the pulse wave interval is calculated, and it is determined whether there is data indicating an irregular pulse wave in the set of data. For each measurement opportunity, an individual determination result indicating whether an irregular pulse wave has occurred is obtained. If an individual determination result showing the occurrence of the irregular pulse wave is obtained in two or more of the three measurement opportunities, it is determined that there is a possibility of atrial fibrillation.

3. The electronic blood pressure monitor as described in claim 2, characterized in that, The time interval between the three measurement opportunities is within a pre-set allowable period.

4. The electronic blood pressure monitor as described in claim 3, characterized in that, The electronic blood pressure monitor has a storage unit that stores the individual judgment result of each measurement opportunity in a corresponding manner with the measurement date and time. The determination unit backtracks from the latest individual determination result and searches the individual determination results stored in the storage unit. As long as the condition that the time interval between the measurement opportunities is within the allowable period is met and the individual determination results for more than three measurement opportunities are met, it determines whether there is a possibility of atrial fibrillation.

5. A method for determining atrial fibrillation in an electronic blood pressure monitor, wherein the electronic blood pressure monitor measures blood pressure based on the pulse wave of the artery at the measurement site, characterized in that... The electronic blood pressure monitor has the following features: The cuff pressure control unit controls the pressure of the cuff worn on the measurement site by applying pressure or depressurizing it. The pressure detection unit detects a cuff pressure signal, representing the pressure of the cuff, during the pressurization or depressurization process based on the cuff pressure control unit. as well as The blood pressure measuring unit extracts a pulse wave signal that overlaps with the cuff pressure signal, representing a pulse wave, and measures blood pressure based on this pulse wave signal; The electronic blood pressure monitor has a normal blood pressure measurement mode and an atrial fibrillation screening mode. In the normal blood pressure measurement mode, the cuff pressure control unit, the pressure detection unit, and the blood pressure measurement unit perform only one blood pressure measurement per measurement opportunity. In the atrial fibrillation screening mode, the cuff pressure control unit, the pressure detection unit, and the blood pressure measurement unit perform more than three blood pressure measurements per measurement opportunity. The atrial fibrillation determination method, in the usual blood pressure measurement mode, has the following features: The step of determining a set of data representing the pulse wave interval based on the pulse wave signal obtained only in one pressurization process or one depressurization process for each measurement opportunity of a particular subject; The step involves amplifying the data sets from three or more testing opportunities for the subject, calculating the average pulse wave interval, and determining the potential for atrial fibrillation based on whether there are any irregular pulse wave data points in the amplified data sets that exceed the average value within a predetermined tolerance range. In the determination step, it is determined whether the data of the irregular pulse waves in the totaled data group representing the pulse wave intervals meet the preset frequency conditions. When the frequency condition is met, a notification is sent urging the user to switch from the normal blood pressure measurement mode to the atrial fibrillation screening mode.

6. An electronic blood pressure monitor, based on measuring blood pressure through the pulse wave of an artery at the site of measurement, characterized in that, have: The cuff pressure control unit controls the pressure of the cuff worn on the measurement site by applying pressure or depressurizing it. The pressure detection unit detects a cuff pressure signal, representing the pressure of the cuff, during the pressurization or depressurization process based on the cuff pressure control unit. The blood pressure measuring unit extracts a pulse wave signal that overlaps with the cuff pressure signal, representing a pulse wave, and measures blood pressure based on this pulse wave signal; The pulse wave interval calculation unit, for each measurement opportunity of a given subject, calculates a set of data representing the pulse wave interval based on the pulse wave signal obtained only during one inflation or depressurization process; and The determination unit aggregates the data sets from three or more testing opportunities for the subject, calculates the average value of the pulse wave intervals, and determines the possibility of atrial fibrillation based on whether there are any irregular pulse wave data in the aggregated data sets that exceed the preset allowable range relative to the average value. The electronic blood pressure monitor has a normal blood pressure measurement mode and an atrial fibrillation screening mode. In the normal blood pressure measurement mode, the cuff pressure control unit, the pressure detection unit, and the blood pressure measurement unit perform only one blood pressure measurement per measurement opportunity. In the atrial fibrillation screening mode, the cuff pressure control unit, the pressure detection unit, and the blood pressure measurement unit perform more than three blood pressure measurements per measurement opportunity. In the normal blood pressure measurement mode, the determination unit determines whether the irregular pulse wave data in the totaled data set representing the pulse wave intervals meets a preset frequency condition. The electronic blood pressure monitor has a mode control unit, which controls the switching from the normal blood pressure measurement mode to the atrial fibrillation screening mode when the frequent occurrence condition is met.

7. A method for determining atrial fibrillation in an electronic blood pressure monitor, wherein the electronic blood pressure monitor measures blood pressure based on the pulse wave of the artery at the measurement site, characterized in that... The electronic blood pressure monitor has the following features: The cuff pressure control unit controls the pressure of the cuff worn on the measurement site by applying pressure or depressurizing it. The pressure detection unit detects a cuff pressure signal, representing the pressure of the cuff, during the pressurization or depressurization process based on the cuff pressure control unit. as well as The blood pressure measuring unit extracts a pulse wave signal that overlaps with the cuff pressure signal, representing a pulse wave, and measures blood pressure based on this pulse wave signal; The electronic blood pressure monitor has a normal blood pressure measurement mode and an atrial fibrillation screening mode. In the normal blood pressure measurement mode, the cuff pressure control unit, the pressure detection unit, and the blood pressure measurement unit perform only one blood pressure measurement per measurement opportunity. In the atrial fibrillation screening mode, the cuff pressure control unit, the pressure detection unit, and the blood pressure measurement unit perform more than three blood pressure measurements per measurement opportunity. The atrial fibrillation determination method, in the usual blood pressure measurement mode, has the following features: The step of determining a set of data representing the pulse wave interval based on the pulse wave signal obtained only in one pressurization process or one depressurization process for each measurement opportunity of a particular subject; The step involves amplifying the data sets from three or more testing opportunities for the subject, calculating the average pulse wave interval, and determining the potential for atrial fibrillation based on whether there are any irregular pulse wave data points in the amplified data sets that exceed the average value within a predetermined tolerance range. In the determination step, it is determined whether the data of the irregular pulse waves in the totaled data group representing the pulse wave intervals meet the preset frequency conditions. When the frequency condition is met, control is performed to switch from the normal blood pressure measurement mode to the atrial fibrillation screening mode.

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