JP5026542B2 - Electronic blood pressure monitor - Google Patents

Description

  The present invention relates to an electronic sphygmomanometer based on a vibration method (oscillometric method) for calculating a systolic blood pressure and a diastolic blood pressure based on an arterial pulse wave component for each heartbeat superimposed on a cuff pressure.

  Blood pressure measurement using such an electronic sphygmomanometer is performed by winding a cuff with a built-in rubber sac around the upper arm of the subject and gradually increasing or reducing the pressure in the cuff. Cuff pressure) The pulse wave due to the pulsation of the blood flow superimposed on the signal is detected, the maximum peak value of the pulse wave is determined, and the pulse wave value obtained by multiplying it by the predetermined ratio α is high corresponding to the time when the peak value is generated The lower cuff pressure corresponding to the time when the crest value obtained by multiplying the different ratio β is generated is set as the lowest blood pressure. Alternatively, there is a variation parameter determination method for determining the timing based on the variation parameter of the arterial pulse wave value (see Patent Document 1).

  However, if a body movement (artifact), which is the movement of the body of the person being measured, occurs during blood pressure measurement, the arm muscles expand and contract and the volume in the cuff changes, resulting in a sudden increase in the cuff pressure signal. The pressure signal is disturbed. When such a disturbance of the pressure signal occurs, the pulse wave cannot be detected accurately, and accurate blood pressure measurement may not be possible.

  Therefore, when detecting a pulse wave superimposed on the cuff pressure signal in the process of gradually increasing or decreasing the pressure in the cuff with an electronic sphygmomanometer, abnormal data including body movements and noise signals are removed. Various calculations have been proposed to calculate the systolic blood pressure and the diastolic blood pressure using only appropriate pulse waves, as can be seen, for example, in Patent Document 2.

Japanese Examined Patent Publication No. 3-62088 Japanese Patent Publication No. 5-32053

  As described above, if the systolic blood pressure and the diastolic blood pressure are calculated only from appropriate pulse waves from which abnormal data and noise signals have been removed, blood pressure can be measured even with some abnormal data and noise. Because there are individual differences in the magnitude of the pulse wave, if the judgment reference value is uniform, a normal pulse wave may be mistakenly detected as a result of body movement, or a pulse wave mixed with body movement may be normal. In some cases, it is difficult to accurately and efficiently detect abnormalities in the pulse wave due to body movement.

  Therefore, in the electronic sphygmomanometer described in Patent Document 2, the blood pressure is measured when the cuff pressure is reduced, and the determination upper limit value and the determination lower limit value are calculated from a part of the pulse wave data detected at that time, Based on the determination upper limit value and the determination lower limit value, normal or abnormal pulse wave data thereafter is determined and the abnormal data is removed. In this way, the individual difference in the magnitude of the pulse wave is reflected in the body movement determination criterion.

However, in this method, since the determination upper limit value and the determination lower limit value are calculated using the pulse wave data detected during the reduction of the cuff pressure for measuring the blood pressure, the abnormal data cannot be determined until the calculation can be performed, Blood pressure measurement cannot be started. Therefore, the time for blood pressure measurement is lengthened. In addition, the calculation process for the upper and lower determination limits and the subsequent process for determining abnormal data are complicated, and the measurement of the subject under measurement is being performed by accurately and efficiently detecting abnormalities in the pulse wave due to body movement. There was a problem that the state could not be determined.

  The present invention has been made to solve such a problem, and it is possible to accurately and efficiently detect an abnormality of a pulse wave due to body movement or the like, and to determine a measurement state of a measurement subject during measurement. For the purpose.

In order to achieve the above object, an electronic sphygmomanometer according to the present invention controls a cuff, a pressurizing unit that pressurizes the pressure in the cuff, a depressurizing unit that depressurizes the pressure in the cuff, and pressurization and depressurization. The control means, the pressure sensor for detecting the pressure in the cuff, and the amplitude of the differential waveform of the pressure detection signal by the pressure sensor, which is the pulse wave amplitude during pressurization, from the pressure sensor output signal during pressurization in the cuff The pressure pulse differential amplitude detecting means for detecting pressure, the pulse wave amplitude detecting means for detecting the pulse wave amplitude during pressure reduction from the output signal of the pressure sensor during pressure reduction in the cuff, and the pulse wave amplitude during pressure reduction A pressure reducing pulse wave differential amplitude detecting means for detecting the differential waveform amplitude of the pressure detection signal by the pressure sensor; and a blood pressure calculating means for calculating a blood pressure value based on the pulse wave amplitude detected by the pressure reducing pulse wave amplitude detecting means. , pressurization pulse wave differential amplitude detecting means Comparing the detected maximum pulse wave amplitude value with the maximum pulse wave amplitude value detected by the pulse wave differential amplitude detecting means during decompression, and detecting a body motion detecting means as a body motion when the value is equal to or greater than a predetermined value The body pulse is detected by the body motion detection means to detect that the measurement state of the subject is abnormal, and the maximum pulse wave amplitude value detected by the pulse wave differential amplitude detection means during pressurization is the pressurization in the cuff. Among them, the first largest amplitude is adopted when the difference between the first largest amplitude and the second largest amplitude of the divided waveform is less than a predetermined value, and the second largest amplitude is adopted when the difference is larger than the predetermined value. It shall be the.

The predetermined multiple of the value obtained by multiplying the maximum pulse wave differential amplitude by a predetermined value is preferably about 2 to 3 times.
You may have an alerting | reporting means to alert | report the state of the to-be-measured person determined by the said measurement state determination means.

  The electronic sphygmomanometer according to the present invention determines a threshold value that is a determination criterion of body motion suitable for the subject in a short time during the pressurization of the cuff pressure, and immediately detects the body motion and the blood pressure based on normal pulse wave data during the decompression. Measurement can be started, abnormalities of pulse waves due to body movements can be detected accurately and efficiently, and the measurement state of the subject under measurement can be determined.

It is a block diagram which shows the structure of one Embodiment of the electronic blood pressure meter by this invention. It is a wave form diagram which shows the example of the output signal (pressure detection signal) of a pressure sensor during the pressurization in a cuff of the electronic sphygmomanometer shown in FIG. 1, and its differential waveform. It is a wave form diagram which shows the example of the output signal (pressure detection signal) of a pressure sensor in the pressure reduction in a cuff of the electronic sphygmomanometer shown in FIG. 1, and its differential waveform. FIG. 4 is a diagram for explaining the relationship between the pulse wave height of the pulse wave component included in the pressure detection signal shown in FIG. 3, the maximum blood pressure and the minimum blood pressure, and the influence of body movement. It is a flowchart which shows the flow of the blood-pressure measurement process by the microcomputer 6 shown in FIG.

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

  First, the configuration of an embodiment of an electronic blood pressure monitor according to the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of the electronic sphygmomanometer, (a) is a schematic configuration diagram of the whole, and (b) is a functional block diagram showing the functional configuration of the storage / calculation means 10 in (a).

  As shown in FIG. 1 (a), this electronic sphygmomanometer includes a cuff 1, a pressurizing means 2, a depressurizing means 3 and a pressure sensor 4 respectively connected to the cuff 1 by a tube 12, and further includes a signal. As a system, an A / D converter 5, a microcomputer 6, an operation means 7, and a display means 8 are provided. In the figure, open bold lines indicate the air flow, and black thick lines indicate the signal flow.

  The cuff 1 is a band-shaped or cylindrical flexible member in which a rubber sac wound around the upper arm or wrist of the measurement subject is integrated. The pressurizing unit 2 is a pressurizing pump that sends air into the cuff through the tube 12 and pressurizes it. The depressurizing unit 3 is a constant-speed depressurizing unit that releases the air in the cuff at a constant speed through the tube 12 and decompresses the remaining air. It consists of a pressure reducing valve for performing rapid pressure reduction that exhausts rapidly.

  The pressure sensor 4 is a sensor that detects the pressure in the cuff 1 and converts it into an electrical signal. For example, a semiconductor pressure conversion element or a strain gauge is used. The A / D converter 5 converts an analog electrical signal (for example, a voltage signal) output from the pressure sensor 4 into a multi-value digital signal.

  The microcomputer 6 is connected to a central processing unit CPU, a read only memory (program memory) ROM, a read / write memory (data memory) RAM, and an input / output unit I / O port. The CPU executes a blood pressure measurement program stored in the ROM by a CPU bus or the like, and executes blood pressure measurement processing. In FIG. It shows.

  The function of the control means 11 is to control the pressurization operation by the pressurization means 2 and the constant speed decompression operation and the rapid decompression operation by the decompression means 3. When a measurement start button (not shown) of the operating means 7 is pressed, the pressurizing pump of the pressurizing means 2 is operated, air is sent into the cuff 1 to rapidly pressurize, and is detected by the pressure sensor 4. When the pressure in the cuff 1 reaches a predetermined value, the pressurizing pump is stopped.

  Thereafter, constant pressure reduction is performed by the decompression means 3. At this time, when a rubber exhaust valve is used as the constant speed pressure reducing valve, the pressure is reduced by the rubber exhaust valve at a substantially constant speed. At the end of blood pressure measurement, a rapid pressure reducing valve provided separately from the rubber exhaust valve is opened, and the air remaining in the cuff 1 is rapidly exhausted. When a solenoid valve is used as the constant speed pressure reducing valve, the opening degree of the solenoid valve is determined according to the detected pressure value in the cuff 1 detected by the pressure sensor 4 so that the pressure in the cuff 1 is reduced at a constant speed. To control. At the end of blood pressure measurement, the solenoid valve is fully opened, and the air remaining in the cuff 1 is rapidly exhausted.

  The function of the storage / calculation means 10 by the microcomputer 6 will be described later.

  The operating means 7 has various buttons and switches operated by the subject at the time of blood pressure measurement. For example, a measurement start button also serving as a power switch, an ID button for inputting the subject's identifier, and a measurement result A memory button or the like is stored as appropriate.

  The display means 8 displays the maximum blood pressure and the minimum blood pressure calculated by the storage / calculation means 10 of the microcomputer 6 and is, for example, a liquid crystal display device. The display means 8 may also display the pulse rate and time, particularly a large body movement.

As shown in FIG. 1B, the storage / calculation means 10 by the microcomputer 6 includes a pressurizing pulse wave differential amplitude detecting means 13, a decompressing pulse wave differential detecting means 14, a decompressing pulse wave differential amplitude detecting means 15, and a body motion detection. Functions of means 16 and blood pressure calculation means 17 are provided.

The pulse wave differential amplitude detecting means 13 during pressurization differentiates the output signal of the pressure sensor input via the A / D converter 5 during pressurization in the cuff 1, and determines the maximum amplitude of the differential wave (by pulse wave). Detect and store.

  The depressurizing pulse wave detecting means 14 detects a pulse wave component included in the output signal of the pressure sensor input via the A / D converter 5 during depressurization in the cuff 1.

  The pulse wave differential amplitude detecting means 15 during decompression detects the pulse wave differential amplitude (h) by differentiating the output signal of the pressure sensor during decompression of the cuff.

The body motion detection means 16 is a value obtained by multiplying the maximum pulse wave differential amplitude detected by the pressurizing pulse wave differential amplitude detection means 13 by a predetermined value (h ×). α) If it is greater than or equal to, it is detected as body movement.

  The blood pressure calculation unit 17 calculates the maximum blood pressure based on the maximum peak value obtained by subtracting the peak value when body motion is detected by the body motion detection unit from each peak value of the pulse wave detected by the decompressing pulse wave detection unit 14. Calculate the minimum blood pressure. The calculation method will be described later.

  The maximum blood pressure and the minimum blood pressure calculated by the blood pressure calculation unit 17 are displayed by the display unit 8.

  Of the body motions detected by the body motion detection means 16, if there is body motion that cannot be calculated accurately even if the peak value of the pulse wave at that time is removed, It may be determined that there is an abnormality affecting the blood pressure value in the state of the measurer, and this is displayed on the display means 8 with a body movement mark, a measurement abnormality mark, or the like.

  In that case, the measurement operation may be stopped when the body movement is detected, and the remaining air in the cuff 1 may be exhausted rapidly.

  Here, FIG. 2 shows an output signal (pressure detection signal Pu) of the pressure sensor 4 during pressurization in the cuff 1 during blood pressure measurement by this electronic sphygmomanometer, and a differential wave (differential) indicating a pressure change speed obtained by differentiating the output signal. An example of the signal Du) is shown. In this figure, the horizontal axis is time [sec], the scale on the left side of the vertical axis is the pressure [mmHg] of the pressure detection signal Pu, and the scale on the right side is the pressurization speed [mmHg / sec] of the differential signal Du.

The amplitude of the differential signal Du depends on the magnitude of the pulse wave detected during pressurization. Therefore, the amplitude h of the differential signal Du is detected and stored. However, the amplitude of the differential signal Du may be due to body movement during pressurization. Therefore, the first largest amplitude and the second largest amplitude of the differential waveform are compared, and when the difference is less than a predetermined value, the first largest amplitude is set as the maximum amplitude h, and when the difference is greater than the predetermined value, the first Therefore, it is better to set the second largest amplitude as the maximum amplitude h.

  This is the function of the pressurizing pulse wave differential amplitude detecting means 13 in FIG. Determination of body motion detection at the time of decompression is h × α obtained by multiplying the maximum pulse wave differential amplitude h during pressurization with the maximum amplitude among the pulse wave differential amplitudes obtained by the pulse wave differential amplitude detection means 13 during pressurization. Used as a reference threshold.

  Then, after pressurizing the cuff 1 to a predetermined pressure, the blood pressure is calculated by detecting the pulse wave while reducing pressure relatively slowly at a substantially constant speed. FIG. 3 shows the output signal of the pressure sensor 4 at that time. An example of (pressure detection signal Pd) and a differential wave (differential signal Dd) indicating a pressure change speed obtained by differentiating the pressure detection signal Pd is shown. In this figure, the horizontal axis is time [sec], the scale on the left side of the vertical axis is the pressure [mmHg] of the pressure detection signal Pd, and the scale on the right side is the pressure reduction rate [mmHg / sec] of the differential signal Dd.

  The pulse wave detecting means 14 during decompression in FIG. 1B detects and stores the starting pressure and pulse wave height of each pulse wave from the pressure detection signal Pd, and the blood pressure calculating means 17 determines the maximum blood pressure based on the pulse wave data. The minimum blood pressure is calculated, details of which will be described later.

  The pulse wave differential amplitude detection means 15 during decompression differentiates the pressure detection signal Pd shown in FIG. 3 to detect each amplitude (differential amplitude) A of the differential signal Dd, and the body motion detection means 16 detects the differential amplitude A. The above-described maximum pulse wave differential amplitude h is compared with a value (h × α) multiplied by α, and body motion is detected when A ≧ h × α. In the example shown in FIG. 3, the large differential amplitude An is greater than or equal to h × α and is detected as body movement.

  By the way, in the pressure detection signal Pd shown in FIG. 3, a pulse wave synchronized with the heartbeat is superimposed on the pressure in the cuff decreasing at a substantially constant rate.

  FIG. 4 shows each pulse wave (including noise components such as body movement) detected by the pulse wave detecting means 14 during pressure reduction shown in FIG. 1B from the pressure detection signal Pd during pressure reduction. The horizontal axis in FIG. 4 is the pulse wave start pressure [mmHg] when each pulse wave starts to rise, and the vertical axis is the pulse wave height (wave height value) [mmHg]. As shown in FIG. 4, the pulse wave height is small when the pressure in the cuff is high, increases as the pressure decreases, and then decreases again after showing the maximum wave height pulse wave Pmax.

  However, the pulse wave Pn mixed with body motion is detected by the body motion detection means 16 as described above as a pulse wave having an abnormal peak value.

  The blood pressure is calculated based on the pulse wave value of the maximum pulse wave value among the pulse wave value values of the normal pulse wave, that is, the wave wave value Hmax of the pulse wave Pmax in the example of FIG. That is, a higher pulse wave start pressure corresponding to a peak value of Hmax × 50% obtained by multiplying the maximum peak value Hmax by a predetermined ratio α, for example, 50% is calculated as a maximum blood pressure (SYS), and the maximum peak value is calculated. A lower pulse wave start pressure corresponding to a peak value of Hmax × 70% obtained by multiplying Hmax by a predetermined ratio β, for example, 70% is calculated as a minimum blood pressure (DIA).

However, if the peak value of the pulse wave Pn mixed with body motion is erroneously determined as the maximum peak value Hmax ′, the maximum blood pressure is calculated as the higher pulse wave start pressure SYS ′ corresponding to the peak value of Hmax ′ × 50%. Thus, the minimum blood pressure is calculated as the lower pulse wave start pressure DIA ′ corresponding to the peak value of Hmax ′ × 70%. Then, since SYS ′ <SYS, DIA ′> DIA, the pulse pressure =
(Maximum blood pressure−minimum blood pressure) is calculated to be small.

Therefore, by detecting body movement as described above and excluding the pulse wave Pn mixed with such body movement from the determination target of the maximum peak value Hmax, the calculation accuracy of the blood pressure value can be improved.
The blood pressure stability determination means 18 in FIG. 1 (b) is added from the maximum pulse wave differential amplitude during pressurization obtained by the pulse wave differential amplitude detection means 13 during pressurization and the pulse wave differential amplitudes of the pulse waves detected before and after that. The pulse wave differential amplitude during pressure reduction, the maximum pulse wave differential amplitude during pressure reduction obtained by the pressure pulse differential amplitude detecting means 15 during pressure reduction, and the pulse wave differential amplitude during pressure reduction from the pulse wave differential amplitude of the pulse wave detected before and after that, To determine whether or not the measured blood pressure is unstable.

  A comparison of the transition of the pulse wave differential amplitude is, for example, a well-known method of calculating an approximate straight line before and after the maximum pulse wave differential amplitude from the maximum pulse wave differential amplitude obtained at the time of pressurization and at the time of decompression and the differential pulse wave amplitude detected before and after that. Each is calculated by comparing the slopes. When the inclinations are compared and there is a large difference, it is determined that the blood pressure is unstable.

  For example, the comparison of the slopes of the approximate straight lines of the pulse wave differential amplitude is performed as follows. First, the difference between the peak value of the maximum pulse wave differential amplitude during pressurization and the pulse wave differential amplitude immediately before (low pressure side) is obtained. Next, the difference between the pressure value when the maximum pulse wave differential amplitude is detected and the pressure value when the pulse wave differential amplitude immediately before (low pressure side) is detected is obtained. Then, the slope L1 of the straight line is calculated by dividing the difference in peak values by the difference in pressure values. Similarly, the slope M1 of the straight line is calculated from the maximum pulse wave differential amplitude during decompression, the peak value of the pulse wave differential amplitude immediately after (low pressure side), and the pressure value when each pulse wave differential amplitude is detected. Similarly, the maximum pulse wave differential amplitude at the time of pressurization, the peak value of the pulse wave differential amplitude immediately after (high-pressure side), and the slope L2 of the straight line from the pressure value when each pulse wave differential amplitude is detected, The slope M2 of the straight line is calculated from the maximum pulse wave differential amplitude, the peak value of the pulse wave differential amplitude immediately before (high-pressure side), and the pressure value when each pulse wave differential amplitude is detected.

When L1 and M1 are compared and are 1.5 times (or more than 2 times), it is determined that there is a large difference in the slope of the approximate line. Similarly, when L2 and M2 are compared and are 1.5 times (or more than 2 times), it is determined that the inclination of the approximate straight line is large.
In the above example, one pulse (three pulses in total) centered on the maximum pulse wave differential amplitude is used as an object, but an approximate straight line with two pulses before and after the maximum pulse wave (five pulses in total) as a target. The blood pressure instability state may be determined by calculating and comparing the slope and the slope.

Moreover, even if there is a large difference between the pressure value at which the maximum pulse wave differential amplitude during pressurization is detected and the pressure value at which the maximum pulse wave differential amplitude during decompression is detected, it is determined that the blood pressure is unstable.
For example, the absolute value of the pressure value at which the maximum pulse wave differential amplitude is detected during pressurization and decompression is compared, and if there is a difference of 20 mmHg or more, it is determined that the blood pressure is unstable. Furthermore, even if the absolute value of the difference between the pressure values at which the maximum pulse wave differential amplitude is detected during pressurization and decompression is greater than or equal to the pressure value for one pulse of the pulse wave during pressurization, it is determined that the blood pressure is unstable. May be.

The pressure value for one pulse of the pulse wave during pressurization is the absolute value of the difference between the pressure values obtained by detecting each of the two pulse wave differential amplitudes that continue during pressurization. The pressure value of any pulse wave differential amplitude may be used as long as it is calculated from the detected pressure values of two pulse wave differential amplitudes that are continuous during pressurization, but is detected immediately before (or immediately after) the maximum pulse wave differential amplitude. If the pressure value for one beat calculated from the pressure value of the pulse wave differential amplitude is used, the blood pressure unstable state can be determined more accurately.
In addition, it can be determined that the blood pressure is unstable by determining that the blood pressure is unstable when both of the above conditions are satisfied, but it is determined that the blood pressure is unstable only by either one of the conditions. May be.

  Since such processing is performed by the microcomputer 6 shown in FIG. 1A, the flow of blood pressure measurement processing by the microcomputer 6 will be described with reference to the flowchart shown in FIG.

  The measurement is started by turning on the measurement start button of the operation means 7, the pressurization in the cuff 1 is started in step S1, and the pressure detected by the pressure sensor 4 is predetermined until it is determined that the pressurization is finished in step S3. During the pressurization, the differential waveform of the pressure detection signal is monitored in step 2, and the maximum pulse wave differential amplitude (h shown in FIG. 2) is detected and stored. In that case, as described above, either one may be selected as the maximum pulse wave differential amplitude h during pressurization depending on the magnitude relationship between the first and second largest pulse waves.

  Thereafter, pressure reduction in the cuff 1 is started in step S4, and pulse waves (each pulse wave start pressure and pulse wave height shown in FIG. 4) are detected and stored in step S5 while reducing pressure at a substantially constant speed.

  Next, the pulse wave differential amplitude during decompression (A shown in FIG. 3) is detected in step S6, and h × α is compared with the pulse wave differential amplitude A during decompression in step S7, and when A ≧ h × α. Detects body movement in step S8, removes the pulse height data at that time, and proceeds to step S9. If A <h × α in step S7, the body movement is not detected and the process proceeds to step S9.

  The value of the magnification α can be arbitrarily set, and thereby the sensitivity of body motion detection can be adjusted. However, it is preferable to set a standard value of about 2 to 3, for example, about 2.5.

  In step S9, the maximum peak value Hmax is determined from the peak value stored as measurement data in step S5, and in step S10, the maximum blood pressure (SYS) and the minimum blood pressure (DIA) are calculated as described above with reference to FIG. Then, the processes in steps S5 to S10 are repeated until it is determined in step S11 that the blood pressure value calculation is finished.

  Here, the end of the blood pressure value calculation in step S11 is that after both the maximum blood pressure and the minimum blood pressure have been calculated, the processing in steps S5 to S10 is further repeated to acquire pulse waves for several beats. Judgment is made based on whether or not a pulse wave having a high value Hmax is detected.

  The end of the blood pressure value calculation in step S11 may be determined only by whether or not both the maximum blood pressure and the minimum blood pressure have been calculated in step S10.

  The reason for this is to finish the measurement as soon as possible so that the cuff can be quickly exhausted. Instead of continuing to detect the pulse wave until the pulse wave can no longer be detected, the pulse wave is detected in step S5. Each time, if it is larger than the previous peak value, it is determined that the maximum peak value Hmax is obtained in step S9, and if the maximum blood pressure and the minimum blood pressure are calculated based on the maximum peak value Hmax in step S10, the pulse between several beats is further obtained. If a wave is detected and a larger pulse wave is detected, the maximum peak value Hmax is updated in step S9, and the maximum blood pressure and the minimum blood pressure are recalculated. However, if the maximum peak value Hmax is not updated, it is determined in step S11 that the blood pressure value calculation is completed.

When it is determined in step S11 that the blood pressure value calculation is completed, the pulse wave amplitude transition detected before and after the maximum pulse wave amplitude value detected by the pressurizing pulse wave detecting means in step S12, and the pulse wave amplitude during decompression are detected. The transition of the pulse wave amplitude detected before and after the maximum pulse wave amplitude value of the pulse wave detected by the detecting means is compared. When a change is detected in the transition of the pulse wave amplitude in step S12, the blood pressure value measured in step S13 detects an unstable state, and when no change is detected in the transition of the pulse wave amplitude, the process proceeds to step S14.
In step S14, the maximum blood pressure and the minimum blood pressure as measurement results are displayed on the display means 8. At that time, if body movement is detected in step S8 or if an unstable state of blood pressure is detected in step S13, the state of the person being measured may be abnormal during measurement and the accuracy of the blood pressure calculation value may be low. Since there are many, it is good to display a body movement mark, a measurement abnormality mark, etc., to notify that there was an abnormality in the measurement, and to urge remeasurement.

    Finally, in step S15, the air in the cuff 1 is rapidly exhausted to finish the pressure reduction, and the measurement process is finished.

When notifying body movement, as described above, the display means 8 is also used to display “with body movement” in characters or figures (marks), or sound, warning sound, warning lamp is lit or blinked. Various means such as blinking the display of the measurement result by the display means 8 or displaying the measurement result in a color different from the normal time can be adopted.
Further, when an unstable state of blood pressure is notified, it is displayed as characters or figures (marks) as in the case of leaving the body movement, or voice, warning sound, warning lamp is turned on or blinking, or display means 8 Various means can be employed, such as blinking the display of the measurement result by, or displaying the measurement result in a color different from the normal state.
In the above-described embodiment, the pulse wave differential amplitude during pressurization and the pressure value at that time are used for detection of body motion and determination of an unstable blood pressure, but the pulse wave amplitude is not the pulse wave differential amplitude. The value and the pressure value at that time may be used.

  When pressurization is rapid and it is difficult to detect a simple pulse wave component, it is easier to detect the amplitude by using the differential pulse wave, but when the pulse wave component can be taken, use a simple pulse wave instead of the differential pulse wave. Can do. The pressure values at which the pulse wave and the differential pulse wave become the maximum pulse wave are substantially the same.

  According to the electronic sphygmomanometer according to the present invention, a threshold value serving as a determination criterion of body motion suitable for the measurement subject is determined in a short time during the pressurization of the cuff pressure. Blood pressure measurement can be started, and abnormal pulse waves due to body motion can be detected accurately and efficiently. Moreover, an unstable state of blood pressure can be detected by comparing the transition of pulse waves during pressurization and decompression. As a result, an abnormality in the state of the person being measured can be detected and notified, so that blood pressure can be measured with high accuracy.

  The electronic sphygmomanometer according to the present invention can be widely applied to various electronic sphygmomanometers based on the oscillometric method for home use, portable electronic sphygmomanometers, and the like, and the reliability thereof can be improved.

1: Cuff 2: Pressurizing means 3: Pressure reducing means 4: Pressure sensor 5: A / D converter 6: Microcomputer 7: Operating means 8: Display means 10: Storage / calculating means 11: Control means 12: Tube 13: Addition Pressure pulse wave differential amplitude detection means 14: Pressure reduction pulse wave detection means 15: Pulse pressure differential amplitude detection means during pressure reduction 16: Body motion detection means 17: Blood pressure calculation means

Claims (3)

With cuff,
A pressurizing means for pressurizing the pressure in the cuff;
Pressure reducing means for reducing the pressure in the cuff;
Control means for controlling the pressurization and decompression;
A pressure sensor for detecting the pressure in the cuff;
During the pressurization in the cuff, from the output signal of the pressure sensor, the pulse wave differential amplitude detection means during pressurization for detecting the amplitude of the differential waveform of the pressure detection signal by the pressure sensor, which is the pulse wave amplitude during pressurization,
Depressurizing pulse wave amplitude detecting means for detecting the pulse wave amplitude during depressurization from the output signal of the pressure sensor during depressurization in the cuff;
Depressurizing pulse wave differential amplitude detecting means for detecting the amplitude of the differential waveform of the pressure detection signal by the pressure sensor which is the pulse wave amplitude during the depressurization;
And blood pressure calculating means for calculating a blood pressure value based on the pulse wave amplitude which said vacuum in pulse wave amplitude detecting means for detecting,
With
When the maximum pulse wave amplitude value detected by the pressurizing pulse wave differential amplitude detecting means and the maximum pulse wave amplitude value detected by the depressurizing pulse wave differential amplitude detecting means are equal to or greater than a predetermined value A body motion detecting means for detecting as body motion, and determining that the measurement state of the measurement subject is abnormal by detecting the body motion by the body motion detecting means,
The maximum pulse wave amplitude value detected by the pulse wave differential amplitude detecting means during pressurization is such that the difference between the first and second largest amplitudes of the differential waveform during pressurization in the cuff is less than a predetermined value. The electronic sphygmomanometer is characterized in that the first largest amplitude is adopted in the case, and the second largest amplitude is adopted in the case where it is equal to or greater than a predetermined value . The electronic sphygmomanometer according to claim 1 , wherein the predetermined multiplied value is 2 to 3 times. The electronic sphygmomanometer according to claim 1 , further comprising notification means for notifying that the measurement state is abnormal when it is determined that the measurement state of the measurement subject is abnormal.