Sphygmomanometer, blood pressure measurement method, and storage medium

Abstract

The blood pressure monitor of the present invention has a storage unit for storing measured blood pressure values. In the nighttime blood pressure measurement mode (S11), blood pressure measurement is automatically started according to a schedule (S12), and when the blood pressure measurement cuff is in the pressurization process or the decompression process, blood pressure is measured (S13 to S20). In addition, it is determined whether the measured blood pressure value this time has a difference exceeding the allowable range relative to the past blood pressure values ​​stored in the storage unit (S21). When the current blood pressure value has a difference exceeding the allowable range relative to the past blood pressure values, it is determined whether one of a plurality of predetermined phenomena has occurred in the subject (S22). Depending on whether one of the plurality of phenomena has occurred, the time for re-measurement relative to the measurement time of the current blood pressure value can be variably set.

Description

Technical Field

[0001] The present invention relates to a sphygmomanometer, and more specifically, to a sphygmomanometer having a nighttime (sleep) blood pressure measurement mode. Furthermore, the present invention relates to a blood pressure measurement method for measuring blood pressure using such a sphygmomanometer. Furthermore, the present invention relates to a storage medium storing a program for causing a computer to execute such a blood pressure measurement method. Background Art

[0002] In the past, as a blood pressure monitor of this type, for example, in Patent Document 1 (International Publication No. 2018 / 168797), a blood pressure monitor was disclosed that, when it was determined that the blood pressure value measured in the blood pressure measurement mode at night (during sleep) may contain an error (measurement error caused by poor posture), measured the blood pressure again after a predetermined set time had passed.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2018 / 168797 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] When measuring blood pressure at night for a long period of time (typically overnight), the subject may experience various phenomena that may affect the blood pressure value, such as changes in sleep state, irregular pulse waves, changes in posture, and body movements.

[0008] However, in the conventional blood pressure monitor described above, in nighttime blood pressure measurement mode, blood pressure is measured again after a certain set time has passed, as the current blood pressure value may contain measurement errors. Therefore, if the set time is too long compared to the phenomenon occurring in the subject (for example, if a wait of more than 30 minutes is required for a few tens of seconds of body movement), the blood pressure measurement may be performed at a time far from the time when the blood pressure measurement should have been performed, resulting in an inability to obtain the appropriate blood pressure value. On the other hand, if the set time is too short compared to the phenomenon occurring in the subject, there is a high possibility that the phenomenon is still continuing at the time of re-measurement, resulting in an inaccurate blood pressure value.

[0009] Therefore, the present invention aims to provide a blood pressure monitor and blood pressure measurement method that, when the current blood pressure value measured in the nighttime blood pressure measurement mode may contain a measurement error, can appropriately set the timing for re-measurement based on a phenomenon occurring in the subject. Furthermore, the present invention aims to provide a storage medium storing a program for causing a computer to execute such a blood pressure measurement method.

[0010] Means used to solve problems

[0011] In order to solve the above-mentioned problems, the blood pressure meter of the present invention measures blood pressure by temporarily pressing the measured part of the subject with a blood pressure measurement cuff, and is characterized in that:

[0012] The blood pressure monitor has a nighttime blood pressure measurement mode that automatically starts blood pressure measurement according to a predetermined schedule.

[0013] The blood pressure monitor has:

[0014] a storage unit for storing the measured blood pressure value;

[0015] a blood pressure measurement unit that automatically starts blood pressure measurement according to the schedule in the nighttime blood pressure measurement mode and measures blood pressure when the blood pressure measurement cuff is in the pressurization process or the depressurization process;

[0016] a difference determination unit for determining whether the currently measured blood pressure value differs from the past blood pressure values ​​stored in the storage unit by exceeding a predetermined allowable range;

[0017] a phenomenon determination unit for determining whether the subject has experienced any one of a plurality of predetermined phenomena that may affect the blood pressure value when the current blood pressure value differs from the past blood pressure value by more than the allowable range; and

[0018] The schedule resetting unit variably sets a remeasurement time relative to the current blood pressure value measurement time, depending on whether any one of the plurality of phenomena has occurred.

[0019] In this specification, "a current blood pressure value differing from a past blood pressure value by more than a predetermined allowable range" typically means that, after accounting for measurement errors, the current blood pressure value is substantially different from the past blood pressure value. The "past blood pressure value" may be, for example, the last blood pressure value obtained in the nighttime blood pressure measurement mode according to the schedule, or the average of the nighttime blood pressure values ​​from the previous day obtained in the nighttime blood pressure measurement mode according to the schedule.

[0020] "Predetermined multiple phenomena" typically refer to phenomena that may affect blood pressure values, such as changes in sleep state, generation of irregular pulse waves, changes in posture, and body movements. "Changes in sleep state" refers to changes in the depth of sleep, such as changes from non-rapid eye movement sleep (deep sleep) to rapid eye movement sleep (light sleep), and changes from rapid eye movement sleep (light sleep) to the awake state. "Generation of irregular pulse waves" refers to a state in which the pulse wave that should be repeated at a constant period / constant intensity becomes disordered (including arrhythmia). "Changes in posture" refers to the phenomenon that the subject switches from a certain posture (typically a supine position in the case of nighttime blood pressure measurement) to another posture. "Body movement" refers to movements of the body that do not conform to changes in posture (for example, repetitive movements).

[0021] "Whether a phenomenon has occurred" refers to whether a phenomenon has occurred at the time of blood pressure measurement. In addition, even if none of the predetermined multiple phenomena have occurred, this is also included in the determination target.

[0022] The "measurement time" of the blood pressure value refers to the time when the blood pressure measurement is automatically started according to the schedule (usually takes about 1 to 2 minutes), and is synonymous with the time when the blood pressure value is actually calculated during the inflation or deinflation process of the blood pressure measurement cuff.

[0023] In the nighttime blood pressure measurement mode, the sphygmomanometer of the present invention automatically starts blood pressure measurement according to the schedule. When the blood pressure cuff is in the process of being pressurized or depressurized, the blood pressure measurement unit measures blood pressure (for example, by calculating the blood pressure value using the oscillometric method based on the pressure of the blood pressure cuff). A difference determination unit determines whether the currently measured blood pressure value differs from past blood pressure values ​​stored in the storage unit by more than a predetermined allowable range. This determines whether the currently measured blood pressure value may contain a measurement error. If the currently measured blood pressure value differs from the past blood pressure value by more than the allowable range, the phenomenon determination unit determines whether the subject has experienced one of multiple predetermined phenomena that may affect the blood pressure value. The schedule resetting unit variably sets the remeasurement time relative to the current blood pressure value measurement time based on whether one of the multiple phenomena has occurred. Therefore, according to this sphygmomanometer, even if the current blood pressure value may contain a measurement error, the remeasurement time can be appropriately set based on the phenomenon occurring in the subject. As a result, it is possible to avoid situations where the remeasurement time is too late or too early relative to the occurring phenomenon.

[0024] In one embodiment of the sphygmomanometer, it is characterized in that:

[0025] The storage unit includes a time difference table for pre-storing, for each of the plurality of phenomena, a relative time difference between the re-measurement times.

[0026] The schedule resetting unit reads the relative time difference stored in the time difference table according to whether any one of the plurality of phenomena occurs, and sets the remeasurement time by adding the read relative time difference to the current blood pressure measurement time.

[0027] The "relative time difference for determining the re-measurement timing" is empirically set in consideration of the normal duration of the corresponding phenomena, such as 30 minutes for "posture change" and 5 minutes for "body movement."

[0028] In this embodiment of the blood pressure monitor, a time difference table pre-stores relative time differences for determining the time of re-measurement for each of the multiple phenomena. The schedule resetting unit reads the relative time difference stored in the time difference table based on whether one of the multiple phenomena has occurred, and adds the read relative time difference to the current blood pressure measurement time to set the time of re-measurement. This allows for smoother setting of the re-measurement time.

[0029] In one embodiment of the sphygmomanometer, it is characterized in that:

[0030] When two or more phenomena among the plurality of phenomena occur overlappingly, the schedule resetting unit selects the longest time difference among the relative time differences read from the time difference table for the two or more phenomena occurring overlappingly.

[0031] In this embodiment of the blood pressure monitor, when two or more of the multiple phenomena occur overlappingly, the schedule resetting unit selects the longest time difference among the relative time differences read from the time difference table for the two or more overlapping phenomena. In other words, the remeasurement timing is set based on the phenomenon that is likely to last the longest among the two or more overlapping phenomena. This avoids situations where remeasurement is initiated while one of the two or more overlapping phenomena (the longest-lasting phenomenon) is still ongoing.

[0032] In one embodiment of the sphygmomanometer, it is characterized in that:

[0033] The blood pressure monitor includes a main body integrally provided with the blood pressure measurement cuff.

[0034] The main body is equipped with the storage unit, the blood pressure measurement unit, the difference determination unit, the phenomenon determination unit, and the schedule resetting unit.

[0035] Here, the “blood pressure measurement unit” includes, for example, a pump that supplies pressurized fluid to the blood pressure measurement cuff, a valve that discharges fluid from the blood pressure measurement cuff, and components that drive and control the pump and valve.

[0036] The blood pressure monitor of this embodiment can be constructed in an integrated and compact manner, thereby facilitating operation by the user.

[0037] In one embodiment of the sphygmomanometer, it is characterized in that:

[0038] The blood pressure measurement unit includes a pressure sensor that detects the pressure of the blood pressure measurement cuff. When the blood pressure measurement cuff is in a pressurization process or a depressurization process, the blood pressure value is obtained by oscillometric measurement based on the pressure of the blood pressure measurement cuff.

[0039] The phenomenon determination unit includes:

[0040] a sleep state determination unit that determines whether the sleep state of the subject has changed based on the pulse rate obtained from the pressure of the blood pressure measurement cuff;

[0041] an irregular pulse wave determination unit that determines whether an irregular pulse wave has occurred based on an interval of the pulse wave obtained from the pressure of the blood pressure measurement cuff;

[0042] a posture determination unit including an acceleration sensor integrally mounted on the main body, and determining whether the posture of the subject has changed based on an output of the acceleration sensor; and

[0043] The body movement determination unit determines whether the subject has experienced body movement based on the output of the acceleration sensor.

[0044] In this embodiment of the blood pressure monitor, relatively few hardware components (especially pressure sensors and acceleration sensors) are used to determine whether the four phenomena mentioned above, namely changes in sleep state, generation of irregular pulse waves, changes in posture, and body movements, have occurred.

[0045] In one embodiment of the blood pressure monitor, the measured site is a wrist.

[0046] Since the blood pressure monitor of this embodiment compresses the wrist, the measured area, it is expected to interfere with the subject's sleep less than a type that compresses the upper wrist (Imai et al., "Development and evaluation of a home nocturnal blood pressure monitoring system using awrist-cuff device", Blood Pressure Monitoring 2018, 23, pp. 318-326). Therefore, this blood pressure monitor is suitable for measuring blood pressure at night (while sleeping).

[0047] On the other hand, the blood pressure measurement method of the present invention is used for a blood pressure meter that measures blood pressure by temporarily compressing a measured portion of a subject with a blood pressure measurement cuff, characterized in that:

[0048] The blood pressure monitor has a nighttime blood pressure measurement mode for automatically starting blood pressure measurement according to a predetermined schedule, and has a storage unit for storing measured blood pressure values.

[0049] The blood pressure measurement method performs the following processing:

[0050] In the nighttime blood pressure measurement mode, blood pressure measurement is automatically started according to the schedule, and blood pressure is measured when the blood pressure measurement cuff is in the pressurization process or the depressurization process.

[0051] determining whether the currently measured blood pressure value differs from the past blood pressure values ​​stored in the storage unit by a difference exceeding a predetermined allowable range,

[0052] When the current blood pressure value differs from the past blood pressure value by more than the allowable range, it is determined whether the subject has experienced any one of a plurality of predetermined phenomena that may affect the blood pressure value.

[0053] The time of re-measurement relative to the time of measurement of the current blood pressure value is variably set according to whether any one of the plurality of phenomena has occurred.

[0054] According to the blood pressure measurement method of the present invention, when the current blood pressure value may contain measurement errors, the remeasurement time is appropriately set according to the phenomenon occurring in the subject. As a result, it is possible to avoid remeasurement being performed too late or too early relative to the phenomenon occurring.

[0055] Furthermore, in yet another aspect, a storage medium of the present invention stores a program for causing a computer to execute the blood pressure measurement method.

[0056] The blood pressure measurement method can be performed by causing a computer to execute the program stored in the storage medium of the present invention.

[0057] Effects of the Invention

[0058] As can be seen from the foregoing, according to the sphygmomanometer and blood pressure measurement method of the present invention, when the current blood pressure value measured in the nighttime blood pressure measurement mode may contain measurement errors, the timing of re-measurement can be appropriately set based on the subject's condition. Furthermore, the program stored on the storage medium of the present invention can cause a computer to execute this blood pressure measurement method. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a diagram showing the appearance of a wrist blood pressure monitor according to one embodiment of the present invention.

[0060] Figure 2 It is a diagram showing the block configuration of a sphygmomanometer.

[0061] Figure 3 1 and 2 are diagrams showing a manner in which the blood pressure monitor is worn on the left wrist, which is the measurement site.

[0062] Figure 4A A diagram showing a sitting position as a measurement posture.

[0063] Figure 4B The figure shows the supine position as a measurement posture.

[0064] Figure 5 This is a diagram showing the operation flow when the blood pressure monitor is used to measure blood pressure in the normal blood pressure measurement mode.

[0065] Figure 6 1 is a diagram showing the operation flow when the blood pressure monitor is used to measure blood pressure in the nighttime blood pressure measurement mode.

[0066] Figure 7 (A) in FIG. 1 is a graph showing the temporal evolution of the cuff pressure PC during blood pressure measurement. Figure 7 (B) in FIG. 1 is a diagram showing the temporal evolution of the pulse wave signal SM accompanying blood pressure measurement. Figure 7 (C) is a diagram showing an envelope ENV set for the sequence of pulse wave amplitudes formed by the pulse wave signal SM.

[0067] Figure 8 This is a diagram explaining the method of calculating blood pressure in the nighttime blood pressure measurement mode.

[0068] 9(A) and 9(B) are diagrams showing a method for determining whether or not there is a difference between the current blood pressure value measured in the nighttime blood pressure measurement mode and the past blood pressure values.

[0069] Figure 10 This is a diagram showing a specific flow of the process of phenomenon identification and schedule resetting in the nighttime blood pressure measurement mode. DETAILED DESCRIPTION

[0070] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0071] (Structure of a blood pressure monitor)

[0072] Figure 1 The external appearance of a wrist-type blood pressure monitor 100 according to one embodiment of the present invention is shown. The blood pressure monitor 100 generally comprises a blood pressure measurement cuff 20 to be worn on the left wrist 90 (see the following) as the measurement site. Figure 3 ); and a main body 10, integrally mounted on the cuff 20.

[0073] The cuff 20 is a common cuff for wrist-type blood pressure monitors and has a long and narrow band shape so as to be wrapped around the left wrist 90 along the circumferential direction. The cuff 20 contains a fluid bag 22 (see FIG. Figure 2 ) In addition, in order to always maintain the cuff 20 in an annular shape, a loop with appropriate flexibility may be provided in the cuff 20.

[0074] like Figure 3 As shown, the main body 10 is integrally attached to a substantially central portion in the longitudinal direction of the band-shaped cuff 20. In this example, the portion where the main body 10 is to be attached corresponds to the palm side surface 90a of the left wrist 90 when worn.

[0075] The main body 10 has a flat, generally rectangular parallelepiped shape that conforms to the outer circumference of the cuff 20. The main body 10 is compact and thin so as not to interfere with the user's (in this example, the subject, and the same applies hereinafter) sleep. Furthermore, the corners of the main body 10 are rounded.

[0076] like Figure 1 As shown, a display 50 constituting a display screen and an operation unit 52 for inputting instructions from the user are provided on the surface (top surface) of the outer surface of the main body 10 that is farthest from the left wrist 90 .

[0077] In this example, the display 50 is comprised of an LCD (Liquid Crystal Display) and displays predetermined information based on control signals from a CPU (Central Processing Unit) 110 (described later). In this example, the display shows the maximum blood pressure (in mmHg), the minimum blood pressure (in mmHg), and the pulse rate (in beats per minute). Alternatively, the display 50 may be comprised of an organic EL (Electro Luminescence) display or an LED (Light Emitting Diode).

[0078] The operating unit 52 inputs an operating signal corresponding to the user's instruction to the CPU 110 described later. In this example, the operating unit 52 includes: a measurement switch 52A for receiving a blood pressure measurement instruction from the user; and a nighttime measurement switch 52B for receiving an instruction to switch the mode between a normal blood pressure measurement mode and a nighttime blood pressure measurement mode. Here, the "normal blood pressure measurement mode" refers to a mode in which blood pressure measurement is performed according to a blood pressure measurement instruction when a blood pressure measurement instruction is input through the measurement switch 52A. The "nighttime blood pressure measurement mode" refers to a mode in which blood pressure measurement is automatically started according to a predetermined schedule so that the user can measure the blood pressure value while sleeping. The predetermined schedule refers to a plan to perform measurements at predetermined times such as 1 a.m., 2 a.m., or 3 a.m., or a plan to perform measurements every two hours, for example, starting from pressing the nighttime measurement switch 52B.

[0079] Specifically, in this example, both the measurement switch 52A and the nighttime measurement switch 52B are momentary (automatic reset) switches, which are in the on state only while being pressed and return to the off state when released.

[0080] While the sphygmomanometer 100 is in normal blood pressure measurement mode, pressing the measurement switch 52A once instructs blood pressure measurement, temporarily compressing the measurement site (left wrist 90) with the cuff 20, and performing oscillometric blood pressure measurement. Pressing the measurement switch 52A again during blood pressure measurement (e.g., while the cuff 20 is being inflated) instructs the blood pressure measurement to stop, immediately terminating the blood pressure measurement.

[0081] While the sphygmomanometer 100 is in the normal blood pressure measurement mode, if the nighttime measurement switch 52B is pressed once, this instructs the monitor to switch to the nighttime blood pressure measurement mode, and the sphygmomanometer 100 switches from the normal blood pressure measurement mode to the nighttime blood pressure measurement mode. In the nighttime blood pressure measurement mode, as described above, oscillometric blood pressure measurement automatically begins according to a predetermined schedule. If the nighttime measurement switch 52B is pressed again while the sphygmomanometer 100 is in the nighttime blood pressure measurement mode, this instructs the monitor 100 to stop the nighttime blood pressure measurement mode, and the monitor 100 switches from the nighttime blood pressure measurement mode to the normal blood pressure measurement mode.

[0082] Even while the sphygmomanometer 100 is in the nighttime blood pressure measurement mode, the user can interrupt the blood pressure measurement by pressing the measurement switch 52A, unlike the predetermined schedule. In this case, in response to the interrupted blood pressure measurement instruction, the cuff 20 temporarily compresses the measurement site (left wrist 90), and blood pressure measurement is performed using the oscillometric method.

[0083] Figure 2 The block structure of the sphygmomanometer 100 is shown.

[0084] As described above, the cuff 20 includes the fluid bag 22 for compressing the measurement site, the left wrist 90. The fluid bag 22 and the main body 10 are connected via the air pipe 39 so that fluid can flow therethrough.

[0085] In addition to the display 50 and operating unit 52 described above, the main body 10 is equipped with a CPU 110 as a control unit, a memory 51 as a storage unit, a power supply unit 53, an acceleration sensor 34, a pressure sensor 31, a pump 32, and a valve 33. Furthermore, the main body 10 is equipped with an A / D conversion circuit 310 that converts the output of the pressure sensor 31 from an analog signal to a digital signal; a pump drive circuit 320 that drives the pump 32; a valve drive circuit 330 that drives the valve 33; and an A / D conversion circuit 340 that converts the output of the acceleration sensor 34 from an analog signal to a digital signal. The pressure sensor 31, pump 32, and valve 33 are connected to the fluid bag 22 via air piping 39 to allow fluid to flow.

[0086] The memory 51 stores programs for controlling the sphygmomanometer 100, data for controlling the sphygmomanometer 100, setting data for setting various functions of the sphygmomanometer 100, and data on blood pressure measurement results, pulse rate, pulse wave interval, and output data from the acceleration sensor 34. The memory 51 is also used as a working memory, etc., during program execution.

[0087] In particular, in this example, the memory 51 stores an algorithm for a sitting position and an algorithm for a supine position as algorithms for calculating blood pressure using the oscillometric method. Figure 4A As shown, the "sitting position" refers to a posture in which the user 80 wearing the blood pressure monitor 100 on the left wrist 90 sits on a chair 97 or the like, places the left elbow on a table 98, and raises the left wrist 90 forward relative to the torso (hand up, elbow down), thereby maintaining the left wrist 90 (and the blood pressure monitor 100) at the height level of the heart 81. This posture eliminates the height difference between the left wrist 90 of the user 80 and the heart 81, and is therefore recommended for improving blood pressure measurement accuracy. On the other hand, as Figure 4B As shown in FIG, the "supine position" refers to a position in which the user 80, wearing the blood pressure monitor 100 on the left wrist 90, lies on his back on a horizontal floor 99 or the like with his left elbow extended along the torso. In this position, a height difference ΔH is generated between the left wrist 90 (and the blood pressure monitor 100) of the user 80 and the heart 81 (the heart 81 is higher than the left wrist 90), which causes deviations in the blood pressure measurement value. In addition, in the sitting position ( Figure 4A ) with the left elbow bent, and in the supine position ( Figure 4B ), the left elbow is extended during the supine position, so the flexion and extension of the left elbow may cause a deviation in the blood pressure measurement value. In order to eliminate this deviation in the blood pressure measurement value in the supine position relative to the blood pressure measurement value in the sitting position, it is preferable to change the blood pressure calculation algorithm for the case of blood pressure measurement in the supine position relative to the blood pressure calculation algorithm for the case of blood pressure measurement in the sitting position. For this reason, in this example, the memory 51 stores an algorithm for the sitting position and an algorithm for the supine position as algorithms for calculating blood pressure using the oscillometric method. The specific method of blood pressure calculation using these algorithms will be described later.

[0088] Furthermore, in this example, as shown in the time difference table in Table 1 below, memory 51 pre-stores relative time differences used to determine the timing of re-measurement for each of a plurality of predetermined phenomena that may occur in the subject during the nighttime blood pressure measurement mode. In this example, the "predetermined plurality of phenomena" refers to four phenomena that may affect blood pressure values: changes in sleep state, the occurrence of irregular pulse waves, changes in posture, and body movement. "Changes in sleep state" refers to changes in sleep depth, such as the transition from non-rapid eye movement (NREM) sleep (deep sleep) to REM sleep (light sleep), or from REM sleep (light sleep) to wakefulness. "Occurrence of irregular pulse waves" refers to the occurrence of disturbances (including arrhythmias) in a pulse wave that should repeat at a constant period and constant intensity. "Posture changes" refer to the subject's transition from a certain posture (typically the supine position in the case of nighttime blood pressure measurement) to another posture. "Body movement" refers to body movements that are inconsistent with changes in posture (e.g., repetitive movements). In this example, a time difference of "30 minutes" for changes in posture, a time difference of "5 minutes" for body movement, a time difference of "15 minutes" for changes in sleep state, and a time difference of "5 minutes" for the occurrence of an irregular pulse wave are stored. These time differences are empirically set based on the typical duration of the corresponding phenomena. A method for determining the specific remeasurement timing using this time difference table will be described later.

[0089] (Table 1) Time difference table

[0090] Phenomenon Time Difference Changes in sleep patterns 15 minutes Generation of irregular pulse waves 5 minutes Changes in posture 30 minutes body movement 5 minutes

[0091] Figure 2 The CPU 110 shown in FIG. 1 controls the overall operation of the sphygmomanometer 100. Specifically, the CPU 110 operates as a pressure control unit according to a program for controlling the sphygmomanometer 100 stored in the memory 51, and controls the driving of the pump 32 and the valve 33 in response to an operation signal from the operation unit 52. Furthermore, the CPU 110 operates as a blood pressure measurement unit, calculates blood pressure values ​​using an algorithm for calculating blood pressure using the oscillometric method, and controls the display 50 and the memory 51.

[0092] In this example, the power supply unit 53 is composed of a rechargeable battery and supplies power to the CPU 110, the pressure sensor 31, the pump 32, the valve 33, the acceleration sensor 34, the display 50, the memory 51, the A / D conversion circuits 310 and 340, the pump drive circuit 320, and the valve drive circuit 330.

[0093] In this example, the acceleration sensor 34 includes a three-axis acceleration sensor integrally mounted on the main body 10. It outputs data indicating the orientation of the gravitational acceleration vector relative to the main body 10 (thus, the posture of the subject wearing the main body 10), data indicating the subject's body motion, and the like. The A / D conversion circuit 340 converts the output of the acceleration sensor 34 from an analog signal to a digital signal and outputs it to the CPU 110. The acceleration sensor 34 functions as a phenomenon determination unit, described later, and in particular, as a component of the posture determination unit and the body motion determination unit.

[0094] The pump 32 supplies air (fluid) to the fluid bag 22 via the air pipe 39 to increase the pressure (cuff pressure) within the fluid bag 22 contained within the cuff 20. The valve 33 opens and closes to control the cuff pressure by either exhausting air from the fluid bag 22 via the air pipe 39 or sealing air into the fluid bag 22. The pump drive circuit 320 drives the pump 32 based on a control signal supplied from the CPU 110. The valve drive circuit 330 opens and closes the valve 33 based on a control signal supplied from the CPU 110.

[0095] The pressure sensor 31 and the A / D conversion circuit 310 operate as a pressure detection unit that detects the pressure of the cuff. In this example, the pressure sensor 31 is a piezo-resistive pressure sensor that outputs the pressure (cuff pressure) within the fluid bag 22 enclosed in the cuff 20 as resistance due to the piezoelectric impedance effect via the air piping 39. The A / D conversion circuit 310 converts the output (resistance) of the pressure sensor 31 from an analog signal to a digital signal and outputs it to the CPU 110. In this example, the CPU 110 operates as an oscillation circuit that oscillates at a frequency corresponding to the resistance from the pressure sensor 31, and obtains a signal representing the cuff pressure based on this oscillation frequency. In addition to operating as a component constituting the blood pressure measurement unit, the pressure sensor 31 also operates as a phenomenon determination unit described later, and in particular, as a component constituting the sleep state determination unit and the irregular pulse wave determination unit.

[0096] (Blood Pressure Measurement Method)

[0097] Figure 5 The flow of operations when a user measures blood pressure in the normal blood pressure measurement mode using the blood pressure monitor 100 is shown. In this example, if the measurement switch 52A is pressed continuously for, for example, 3 seconds or more in the power-off state, the power is turned on, and the normal blood pressure measurement mode is entered by default.

[0098] like Figure 4A As shown, user 80 wearing blood pressure monitor 100 on left wrist 90 is sitting.

[0099] In this state, if Figure 5As shown in step S1, when the user presses the measurement switch 52A provided on the main body 10 and inputs a blood pressure measurement instruction, the CPU 110 initializes the pressure sensor 31 (step S2). Specifically, the CPU 110 initializes the processing storage area, turns off (stops) the pump 32, opens the valve 33, and adjusts the pressure sensor 31 to 0 mmHg (setting the atmospheric pressure to 0 mmHg).

[0100] Next, the CPU 110 closes the valve 33 via the valve drive circuit 330 (step S3), and then turns on (starts) the pump 32 via the pump drive circuit 320 to start pressurizing the cuff 20 (fluid bag 22) (step S4). At this time, the CPU 110 supplies air from the pump 32 to the fluid bag 22 through the air pipe 39, and based on the output of the pressure sensor 31, as shown in FIG. Figure 7 As shown in (A) in FIG. 1 , the inflation speed of the cuff pressure PC, which is the pressure in the fluid bag 22 , is controlled.

[0101] Next, in Figure 5 In step S5, the CPU 110 operates as a blood pressure measurement unit and calculates the blood pressure based on the pulse wave signal SM (the pulse wave variation component included in the output of the pressure sensor 31) acquired at that time (see Figure 7 (B) in the figure), an algorithm for sitting position stored in the memory 51 is used to try to calculate the blood pressure values ​​(maximum blood pressure (systolic blood pressure) and minimum blood pressure (diastolic blood pressure)).

[0102] At this point, if the blood pressure value cannot be calculated due to insufficient data ("No" in step S6), the processing of steps S4 to S6 is repeated as long as the cuff pressure PC does not reach the upper limit pressure (for example, predetermined to 300 mmHg for safety reasons).

[0103] The CPU 110 calculates the blood pressure value in the following manner. That is, the blood pressure value obtained from the cuff pressure PC when the cuff 20 is in the pressurization process is calculated. Figure 7 The sequence of pulse wave amplitudes (peak to peak) formed by the pulse wave signal SM shown in (B) is set Figure 7 At the same time, a predetermined ratio α is set for the maximum value AmpMax of the envelope ENV used when sitting. dia , α sys There are two threshold levels THD1 and THS1. THD1 is the threshold level for diastolic blood pressure and is set to THD1 = α dia ×AmpMax. In addition, THS1 is the threshold level for systolic blood pressure and is set as THS1 = α sys ×AmpMax. As an example, set αdia =0.75, and set α sys = 0.4 (that is, THD1 is set to 0.75 × AmpMax, and THS1 is set to 0.4 × AmpMax.) Then, as Figure 7 As shown in (A) in FIG. 1 , the cuff pressure PC at the time when the envelope ENV crosses the threshold levels THD1 and THS1 is calculated as the lowest blood pressure (diastolic blood pressure) BPdial and the highest blood pressure (systolic blood pressure) BPsys1, respectively.

[0104] When the blood pressure value is calculated in this manner (YES in step S6 ), the CPU 110 turns off the pump 32 (step S7 ), opens the valve 33 (step S8 ), and performs control to discharge the air in the cuff 20 (fluid bag 22 ).

[0105] Furthermore, while repeating the processing of steps S4 to S6 , CPU 110 counts the pulse wave obtained from the cuff pressure PC to calculate the pulse rate (unit: beats / minute).

[0106] Then, the CPU 110 displays the calculated blood pressure value and pulse rate on the display 50 (step S9 ), and performs control to store data such as the blood pressure value and pulse rate in the memory 51 .

[0107] Figure 6 The following is an operational flow when a user measures blood pressure in the nighttime blood pressure measurement mode using the blood pressure monitor 100. At the beginning of this flow, the blood pressure monitor 100 is in the normal blood pressure measurement mode.

[0108] like Figure 6 As shown in step S11, when the user presses the nighttime measurement switch 52B provided on the main body 10, the blood pressure monitor 100 switches from the normal blood pressure measurement mode to the nighttime blood pressure measurement mode. In this example, in the nighttime blood pressure measurement mode, a schedule is set to perform measurements every hour from the time the nighttime measurement switch 52B is pressed until, for example, 7:00 AM. However, this schedule is not limited to this; a schedule may also be set to perform measurements at predetermined times, such as 1:00 AM, 2:00 AM, or 3:00 AM, from the time the nighttime measurement switch 52B is pressed until 7:00 AM.

[0109] Next, if Figure 6 As shown in step S12, CPU 110 determines whether it is the measurement time specified in the schedule (for the nighttime blood pressure measurement mode). If it is not the measurement time specified in the schedule ("No" in step S12), it waits for the measurement time specified in the schedule to become.

[0110] If it is the measurement time specified in the above schedule ("Yes" in step S12), Figure 6 As shown in steps S13 to S15, CPU 110 Figure 5 Blood pressure measurement is started in the same manner as in steps S2 to S4. That is, CPU 110 first initializes pressure sensor 31 (step S13).

[0111] Next, the CPU 110 closes the valve 33 via the valve drive circuit 330 (step S14), and then turns on (starts) the pump 32 via the pump drive circuit 320 to start pressurizing the cuff 20 (fluid bag 22) (step S15). Figure 7 In the same manner as in the case (A), the pressure increase speed of the cuff pressure PC is controlled.

[0112] Next, in Figure 6 In step S16, the CPU 110 operates as a blood pressure measurement unit and measures the blood pressure based on the pulse wave signal SM (the pulse wave variation component included in the output of the pressure sensor 31) acquired at that time (and Figure 7 (The same as the situation shown in (B) in the figure), the algorithm for the supine position is used to try to calculate the blood pressure values ​​(maximum blood pressure (systolic blood pressure) and minimum blood pressure (diastolic blood pressure)).

[0113] At this point, if the blood pressure value cannot be calculated due to insufficient data ("No" in step S17), the processing of steps S15 to S17 is repeated as long as the cuff pressure PC does not reach the upper limit pressure (for example, predetermined to 300 mmHg for safety reasons).

[0114] Here, the CPU 110 calculates the blood pressure value in the following manner. That is, for the sequence of pulse wave amplitudes (peak to peak) formed by the pulse wave signal SM obtained from the cuff pressure PC when the cuff 20 is in the process of being pressurized, Figure 8 The envelope ENV (with Figure 7 The same as the situation shown in (C) in FIG. 1 ). In the algorithm for the supine position, if Figure 8 As shown in FIG, THD2 = 0.6 × AmpMax is used as the threshold level for diastolic blood pressure instead of THD1 = 0.75 × AmpMax, and THS2 = 0.5 × AmpMax is used as the threshold level for systolic blood pressure instead of THS1 = 0.4 × AmpMax. Figure 4B ) blood pressure measurements relative to those in the sitting position ( Figure 4A) of the blood pressure measurement value. The cuff pressure PC at the moment when the envelope ENV crosses the currently set supine position threshold levels THD2 (= 0.6 × AmpMax) and THS2 (= 0.5 × AmpMax) is calculated as the minimum blood pressure (diastolic blood pressure) BPdia2 and the maximum blood pressure (systolic blood pressure) BPsys2, respectively.

[0115] In nighttime blood pressure measurement mode, it is usually recommended that the user be in the supine position. Therefore, by using the supine position algorithm, blood pressure values ​​(maximum and minimum blood pressure) can be calculated stably and with high accuracy.

[0116] When the blood pressure value (this time's blood pressure value) is calculated in this manner (YES in step S17 ), CPU 110 turns off pump 32 (step S18 ) and opens valve 33 (step S19 ) to perform control to discharge the air in cuff 20 (fluid bag 22 ).

[0117] Furthermore, while repeating steps S15 to S17, CPU 110 counts the pulse waves obtained from cuff pressure PC to calculate the pulse rate (in beats per minute) and pulse wave interval (in seconds) for the purpose of determining phenomena described below, particularly determining a sleep state and irregular pulse waves. Simultaneously, CPU 110 acquires output data from acceleration sensor 34 for the purpose of determining posture and body movement, described below.

[0118] The CPU 110 then displays the calculated blood pressure value and pulse rate on the display 50 (step S20 ), and controls the memory 51 to store the current blood pressure value, pulse rate, pulse wave interval data, and output data of the acceleration sensor 34 .

[0119] When a blood pressure measurement specified in the aforementioned schedule is completed in this manner, the CPU 110 operates as a difference determination unit in step S21 to determine whether the current blood pressure value differs from the previous blood pressure value. Specifically, this determination is performed as follows. Furthermore, this determination compares the current blood pressure value with the previous blood pressure value at the highest blood pressure (systolic blood pressure).

[0120] i) One method of determining whether the current blood pressure value is different from the past blood pressure value

[0121] For example, the previous blood pressure value, which is a past blood pressure value, is acquired at 2:00 AM, and the current blood pressure value is acquired at 3:00 AM. In this case, as shown in step S31 of FIG9(A), CPU 110 reads the previous blood pressure value (in this example, 2:00 AM) from memory 51. Next, as shown in step S32, CPU 110 determines whether the current blood pressure value (in this example, 3:00 AM) differs from the previous blood pressure value by more than a predetermined allowable range (in this example, 20 mmHg). If the current blood pressure value differs from the previous blood pressure value by more than 20 mmHg ("Yes" in step S32), it is determined that the current blood pressure value differs from the previous blood pressure value (step S33). On the other hand, if the difference between the current blood pressure value and the previous blood pressure value is less than 20 mmHg ("No" in step S32), it is determined that the current blood pressure value does not differ from the previous blood pressure value (step S34).

[0122] ii) Method 2 for determining whether the current blood pressure value is different from the previous blood pressure value

[0123] Furthermore, multiple nighttime blood pressure values ​​are measured according to the schedule of the nighttime blood pressure measurement mode for the previous day and stored in memory 51 as past blood pressure values. This current blood pressure value is also obtained at 3:00 AM, similar to the above example. In this case, as shown in step S41 of FIG9(B), CPU 110 reads all nighttime blood pressure values ​​from memory 51 for the previous day. Next, as shown in step S42, CPU 110 calculates the average of the nighttime blood pressure values ​​for the previous day. Next, as shown in step S43, CPU 110 determines whether the current blood pressure value (in this example, at 3:00 AM) differs from the previous day's nighttime average (the average of the nighttime blood pressure values) by a value exceeding a predetermined allowable range (in this example, 20 mmHg). If the current blood pressure value differs from the previous blood pressure value by 20 mmHg or more ("YES" in step S43), it is determined that the current blood pressure value differs from the past blood pressure value (step S44). On the other hand, if the difference between the current blood pressure value and the previous blood pressure value is less than 20 mmHg (No in step S43), it is determined that the current blood pressure value has “no difference” from the past blood pressure value (step S45).

[0124] Typically, CPU 110 determines whether the current blood pressure value differs from the previous blood pressure value using either of the determination methods shown in FIG. 9(A) and FIG. 9(B). However, this is not limiting. CPU 110 may also perform both the determination methods shown in FIG. 9(A) and FIG. 9(B) each time a measurement is performed. If either method determines that a difference exists, CPU 110 determines that the current blood pressure value differs from the previous blood pressure value. This allows for widespread detection of situations where the current measurement value may contain a measurement error. Alternatively, CPU 110 may determine that the current blood pressure value differs from the previous blood pressure value only if either determination method determines that a difference exists. This allows for power conservation by performing the phenomenon identification and schedule resetting processes (steps S22 and S23) described later, provided that there is a high likelihood that the current measurement value contains a measurement error.

[0125] In this way, in Figure 6 In step S21, it is determined whether the current blood pressure value is different from the past blood pressure value. Thus, it is determined whether the current blood pressure value may contain a measurement error.

[0126] If it is determined that there is "no difference" between the current blood pressure value and the past blood pressure value ("No" in step S21), the process proceeds to step S24, where CPU 110 determines whether all blood pressure measurements specified in the above schedule have been completed.

[0127] If there are still blood pressure measurements scheduled according to the schedule ("Not Completed" in step S24), the process returns to step S12. The process then waits for the next measurement time specified in the schedule ("No" in step S12). If the next measurement time specified in the schedule has arrived ("Yes" in step S12), CPU 110 repeats the processes of steps S13 to S20.

[0128] On the other hand, Figure 6In step S21, if it is determined that the current blood pressure value differs from the previous blood pressure value ("Yes" in step S21), the process proceeds to steps S22 and S23, where CPU 110 operates as a phenomenon determination unit and a schedule resetting unit. Specifically, when the current blood pressure value differs from the previous blood pressure value by more than the aforementioned allowable range (20 mmHg in the above example), the phenomenon determination unit determines whether the subject has experienced any of a plurality of predetermined phenomena (in this example, four phenomena that may affect the blood pressure value, such as a change in sleep state, the occurrence of an irregular pulse wave, a change in posture, and body movement) (step S22). Furthermore, the schedule resetting unit variably sets the time for re-measurement relative to the time of measurement of the current blood pressure value, depending on whether any of the aforementioned phenomena has occurred (step S23).

[0129] Specifically, the process of phenomenon identification and schedule resetting is based on Figure 10 In this example, the Figure 10 Process B1 of steps S51 to S55 and process B2 of steps S56 to S60 in the figure. Process B1 includes phenomenon discrimination processing based on data on the pulse rate and pulse wave interval calculated from the output of pressure sensor 31. Process B2 includes phenomenon discrimination processing based on data indicating the orientation of the gravitational acceleration vector relative to main body 10 (and therefore, the posture of the subject wearing main body 10) obtained from the output of acceleration sensor 34 and data indicating the subject's body motion.

[0130] In process B1, first, in step S51, CPU 110 operates as a sleep state determination unit and determines whether the subject's sleep state has changed based on the pulse rate data stored in memory 51. Specifically, CPU 110 detects whether the subject's sleep state is deep sleep (non-rapid eye movement sleep) or light sleep (rapid eye movement sleep) based on changes in pulse rate, using methods such as those disclosed in Japanese Patent Application Laid-Open Nos. 2001-061819 and 2007-199025, and whether the subject has transitioned from sleep to wakefulness. As a simple example, if the pulse rate changes by more than ±20 percent from a past average value (e.g., 70 beats / minute), CPU 110 determines that the subject's sleep state has changed from non-rapid eye movement sleep to rapid eye movement sleep or wakefulness ("Yes" in step S51). At this time, CPU 110 reads the time difference of 15 minutes corresponding to "change in sleep state" as a candidate from the time difference table (see Table 1) in memory 51 (step S52). On the other hand, in cases other than the above, CPU 110 determines that there is no change in sleep state ("No" in step S51) and proceeds to step S53.

[0131] In step S53, CPU 110 functions as an irregular pulse wave determination unit, determining whether an irregular pulse wave has occurred based on the pulse wave interval data stored in memory 51. Specifically, CPU 110 determines that an irregular pulse wave has occurred if the pulse wave interval deviates by ±25% or more from the average pulse wave interval in the past, using the known methods disclosed in Japanese Patent Application Laid-Open Nos. 2018-102670 and 2019-115614 ("Yes" in step S53). In this case, CPU 110 reads the 5-minute time difference corresponding to "occurrence of an irregular pulse wave" from the time difference table in memory 51 (see Table 1) as a candidate (step S54). On the other hand, if this is not the case, CPU 110 determines that the pulse wave is regular ("No" in step S53). In this case, CPU 110 selects no time difference (zero) as a candidate (step S55).

[0132] In process B2, first, in step S56, CPU 110 acts as a posture determination unit and determines whether the subject's posture has changed based on the output data of the acceleration sensor 34 stored in the memory 51, in particular, based on the data indicating the orientation of the gravity acceleration vector relative to the main body 10. Specifically, CPU 110 determines that the subject's posture has changed ("Yes" in step S56) when the orientation of the gravity acceleration vector relative to the main body 10 exceeds a predetermined threshold value using a known method disclosed in, for example, Japanese Patent No. 3297971 and Japanese Patent Application Laid-Open No. 2013-183975. At this time, CPU 110 reads the time difference corresponding to "posture change" of 30 minutes from the time difference table (see Table 1) in memory 51 as a candidate (step S57). On the other hand, if this is not the case, CPU 110 determines that there is no posture change ("No" in step S56) and proceeds to step S58.

[0133] In step S58, CPU 110 functions as a body movement determination unit to determine whether the subject has experienced body movement based on the output data of acceleration sensor 34 stored in memory 51, particularly based on changes in the output of acceleration sensor 34. Specifically, CPU 110 determines whether the subject has experienced body movement based on changes in the output of acceleration sensor 34 using a known method such as disclosed in Japanese Patent Application Laid-Open No. 2017-118982. Specifically, during blood pressure measurement, the average values ​​<αx>, <αy>, and <αz> of the outputs αx, αy, and αz of acceleration sensor 34 are calculated for each unit period (e.g., one or several seconds). Furthermore, the amounts of change (αx-<αx>), (αy-<αy>), and (αz-<αz>) of the acceleration outputs αx, αy, and αz relative to the average values ​​<αx>, <αy>, and <αz>, respectively, are calculated at each time point within the unit period. Then, when the square root of the sum of the squares of these changes {(αx-<αx>) 2 +(αy-<αy>) 2 +(αz-<αz>) 2 ) 1 / 2 If the time difference exceeds a predetermined threshold (set as Δα), it is determined that there is body movement ("YES" in step S58). At this time, CPU 110 reads the time difference corresponding to "body movement" of 5 minutes from the time difference table (see Table 1) in memory 51 as a candidate (step S59). On the other hand, if this is not the case, CPU 110 determines that there is no body movement ("NO" in step S58). At this time, CPU 110 sets no time difference (zero) as a candidate (step S60).

[0134] After processes B1 and B2, in step S61, CPU 110 functions as a schedule resetting unit, adding the relative time difference read from the time difference table to the current blood pressure measurement time to set the time for re-measurement. For example, if the current blood pressure measurement time is 3:00 AM, and the relative time difference read is only 15 minutes, corresponding to a "change in sleep state," the re-measurement time is set to 3:15 AM. This allows for smooth re-measurement time setting.

[0135] When two or more of the aforementioned multiple phenomena overlap at the time of the current blood pressure measurement, processes B1 and B2 read two or more of the aforementioned relative time differences from the time difference table. For example, when a posture change and an irregular pulse wave overlap at the time of the current blood pressure measurement, processes B1 and B2 read a relative time difference of 30 minutes corresponding to the posture change and a relative time difference of 5 minutes corresponding to the irregular pulse wave. In step S61, CPU 110 selects the longest time difference from the relative time differences read from the time difference table for the two or more overlapping phenomena. In the above example, the longest time difference of 30 minutes is selected from the relative time difference of 30 minutes corresponding to the posture change and the relative time difference of 5 minutes corresponding to the irregular pulse wave. CPU 110 then adds the selected longest time difference of 30 minutes to the current blood pressure measurement time (e.g., 3:00 AM) and sets the time of the next measurement to 3:30 AM. In this manner, CPU 110 sets the re-measurement timing based on the longest-lasting phenomenon of the two or more overlapping phenomena. This avoids situations where re-measurement is initiated while one of the two or more overlapping phenomena (the longest-lasting phenomenon, in the above example, a change in posture) is still ongoing.

[0136] Furthermore, if there is no time difference (zero) as a candidate through processes B1 and B2 (particularly, steps S55 and S60 ), the CPU 110 does not set the time for re-measurement in step S61 .

[0137] If the phenomenon identification and schedule resetting process are completed in this way ( Figure 10 ,Right now, Figure 6 Steps S22 and S23) then proceed to Figure 6 In step S24, it is determined whether all blood pressure measurements specified in the above-mentioned schedule (including the remeasurements set by the above-mentioned phenomenon discrimination and schedule resetting processing) have been completed.

[0138] However, if there is still blood pressure measurement scheduled according to the above schedule ("Not Completed" in step S24), the process returns to step S12 and then waits for the next measurement time specified in the above schedule ("No" in step S12).

[0139] If the next measurement time specified in the schedule has arrived ("YES" in step S12), CPU 110 repeats the processes of steps S13 to S20. In this manner, CPU 110 repeats the measurement as long as there are blood pressure measurements scheduled according to the schedule ("Not Completed" in step S21). When all blood pressure measurements specified in the schedule are completed ("Ended" in step S24), the nighttime blood pressure measurement mode ends.

[0140] Thus, according to the sphygmomanometer 100, when the current blood pressure value may contain a measurement error (in Figure 6 In step S21 of the test, the re-measurement time is appropriately set according to the phenomenon occurring in the subject ( Figure 6 As a result, it is possible to avoid a situation where the remeasurement timing is too late compared to the phenomenon that has occurred, or the remeasurement timing is too early compared to the phenomenon that has occurred.

[0141] Furthermore, since this blood pressure monitor 100 compresses the wrist (the left wrist 90 in the above example, but the right wrist is also acceptable) as the measured part, it is expected to interfere with the user's (subject's) sleep less than a type that compresses the upper arm (Imai et al., "Development and evaluation of a home nocturnal blood pressure monitoring system using a wrist-cuff device," Blood Pressure Monitoring 2018, 23, pp. 318-326). Therefore, this blood pressure monitor 100 is suitable for nighttime blood pressure measurement.

[0142] Furthermore, the blood pressure monitor 100 is integrally and compactly configured as a wrist blood pressure monitor, and thus is easy for the user to operate.

[0143] Furthermore, the blood pressure monitor 100 uses relatively few hardware components (particularly, the pressure sensor 31 and the acceleration sensor 34) to determine whether the four aforementioned multiple phenomena, namely, changes in sleep state, generation of irregular pulse waves, changes in posture, and body movements, have occurred.

[0144] (Variation)

[0145] In the above embodiment, the blood pressure is calculated while the cuff 20 (fluid bag 22) is being inflated, but the present invention is not limited thereto. The blood pressure may be calculated while the cuff 20 is being deflated.

[0146] In addition, in the above embodiment, although the blood pressure measurement instruction and the instruction to switch to the nighttime blood pressure measurement mode are input via the measurement switch 52A and the nighttime measurement switch 52B as the operation unit provided on the main body 10, this is not limiting. For example, the main body 10 may be equipped with a communication unit capable of wireless communication, and the blood pressure measurement instruction and the instruction to switch to the nighttime blood pressure measurement mode may be input via this communication unit from a smartphone or the like located outside the blood pressure monitor 100.

[0147] In the above embodiment, the main body 10 and the cuff 20 are integrally provided, but the present invention is not limited thereto. The main body 10 may be configured as a separate body from the cuff 20 and connected to the cuff 20 (fluid bag 22) via a flexible air tube so that fluid can flow.

[0148] The above-mentioned blood pressure measurement method (especially, Figure 5 、 Figure 6 , Figure 9(A), Figure 9(B), Figure 10 The blood pressure measurement method described above can be performed by installing the software (computer program) recorded on a recording medium capable of non-temporary data storage, such as a CD (Compact Disc), a DVD (Digital Versatile Disc), or a flash memory. By installing the software recorded on such a recording medium on a physical computer device, such as a personal computer, a PDA (Personal Digital Assistant), or a smartphone, the computer device can be caused to execute the blood pressure measurement method described above.

[0149] In the above embodiment, the oscillometric method is used as the blood pressure measurement method, but the present invention is not limited thereto. As the blood pressure measurement method, a method of observing Korotkoff sounds by installing a microphone (Korotkoff method) may also be used.

[0150] The above embodiments are illustrative and can be modified in various ways without departing from the scope of the present invention. The above multiple embodiments can be established independently, but the embodiments can also be combined with each other. In addition, the various features in different embodiments can also be established independently, but the features in different embodiments can also be combined with each other.

[0151] Description of reference numerals:

[0152] 10: Main body

[0153] 20: Blood pressure measurement cuff

[0154] 31: Pressure sensor

[0155] 34: Accelerometer

[0156] 50: Display

[0157] 51: Memory

[0158] 52: Operation Department

[0159] 52A: Measuring switch

[0160] 52B: Night measurement switch

[0161] 110: CPU

Claims

1. A blood pressure monitor that measures blood pressure by temporarily compressing a measured area of ​​a subject with a blood pressure measurement cuff, wherein: The blood pressure monitor has a nighttime blood pressure measurement mode that automatically starts blood pressure measurement according to a predetermined schedule. The blood pressure monitor has: a storage unit for storing the measured blood pressure value; a blood pressure measurement unit that automatically starts blood pressure measurement according to the schedule in the nighttime blood pressure measurement mode and measures blood pressure when the blood pressure measurement cuff is in the pressurization process or the depressurization process; a difference determination unit for determining whether the currently measured blood pressure value differs from the past blood pressure values ​​stored in the storage unit by exceeding a predetermined allowable range; a phenomenon determination unit for determining whether the subject has experienced any one of a plurality of predetermined phenomena that may affect the blood pressure value when the current blood pressure value differs from the past blood pressure value by more than the allowable range; as well as The schedule resetting unit sets a remeasurement time relative to the current blood pressure value measurement time by adding a predetermined relative time difference based on whether any one of the plurality of phenomena has occurred.

2. The blood pressure monitor according to claim 1, wherein The storage unit includes a time difference table for pre-storing the relative time difference for each of the plurality of phenomena. The schedule resetting unit reads the relative time difference stored in the time difference table according to whether any one of the plurality of phenomena occurs, and sets the remeasurement time by adding the read relative time difference to the current blood pressure measurement time.

3. The blood pressure monitor according to claim 2, wherein: When two or more phenomena among the plurality of phenomena occur overlappingly, the schedule resetting unit selects the longest time difference among the relative time differences read from the time difference table for the two or more phenomena occurring overlappingly.

4. The sphygmomanometer according to any one of claims 1 to 3, characterized in that The blood pressure monitor includes a main body integrally provided with the blood pressure measurement cuff. The main body is equipped with the storage unit, the blood pressure measurement unit, the difference determination unit, the phenomenon determination unit, and the schedule resetting unit.

5. The blood pressure monitor according to claim 4, wherein: The blood pressure measurement unit includes a pressure sensor that detects the pressure of the blood pressure measurement cuff. When the blood pressure measurement cuff is in a pressurization process or a depressurization process, the blood pressure value is obtained by oscillometric measurement based on the pressure of the blood pressure measurement cuff. The phenomenon determination unit includes: a sleep state determination unit that determines whether the sleep state of the subject has changed based on the pulse rate obtained from the pressure of the blood pressure measurement cuff; an irregular pulse wave determination unit that determines whether an irregular pulse wave has occurred based on an interval of the pulse wave obtained from the pressure of the blood pressure measurement cuff; a posture determination unit including an acceleration sensor integrally mounted on the main body, and determining whether the posture of the subject has changed based on an output of the acceleration sensor; as well as The body movement determination unit determines whether the subject has experienced body movement based on the output of the acceleration sensor.

6. The sphygmomanometer according to any one of claims 1 to 3, characterized in that The measured part is the wrist.

7. A blood pressure measurement method, wherein a blood pressure measuring cuff is used to temporarily compress a measured portion of a subject to measure blood pressure, wherein the blood pressure measuring method comprises: The blood pressure monitor has a nighttime blood pressure measurement mode for automatically starting blood pressure measurement according to a predetermined schedule, and has a storage unit for storing measured blood pressure values. The blood pressure measurement method performs the following processing: In the nighttime blood pressure measurement mode, blood pressure measurement is automatically started according to the schedule, and blood pressure is measured when the blood pressure measurement cuff is in the pressurization process or the depressurization process. determining whether the currently measured blood pressure value differs from the past blood pressure values ​​stored in the storage unit by a difference exceeding a predetermined allowable range, When the current blood pressure value differs from the past blood pressure value by more than the allowable range, it is determined whether the subject has experienced any one of a plurality of predetermined phenomena that may affect the blood pressure value. The time for re-measurement relative to the time of measurement of the current blood pressure value is set by adding a predetermined relative time difference based on whether any one of the plurality of phenomena has occurred. 8 . A storage medium storing a program for causing a computer to execute the blood pressure measurement method according to claim 7 .

Images