JP2011200574A - Electronic sphygmomanometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability of an electronic sphygmomanometer by making it urge remeasurement by announcing a body movement such as to exert a great influence on the result of measurement only when detecting the body movement.SOLUTION: The electronic sphygmomanometer detects pressure in a cuff by a pressure sensor 4 while the pressure in the cuff 1 is increased by a pressurization unit 2, or while the pressure is decreased by a depressurization unit 3, detects a pulse wave component included in a detection signal by a pulse wave detection unit 13, decides on noise in the pulse wave by a noise separation and storage unit 14, stores the crest value as a noise value separately from the crest value of a normal pulse wave, computes a maximum blood pressure and a lowest blood pressure on the basis of the largest crest value of the normal pulse wave by a blood pressure computation unit 15, displays it on a display unit 8, compares the maximum noise value from among the stored noise values with the maximum crest value by a body movement detection unit 16, and detects noise as the body movement when there is a difference or a ratio of a fixed value or higher and announces the body movement by a body movement announcement unit 9.

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 at which the crest value obtained by multiplying the different ratio β is generated is set as the lowest blood pressure with the higher cuff pressure as the highest blood pressure (see Patent Document 1).

  However, if body movements (artifacts) such as the body movement of the subject's arm or fingers occur 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. Depressurization or pressurization occurs. When such a sudden change in cuff pressure occurs, the pulse wave cannot be accurately detected, which adversely affects blood pressure measurement accuracy.

  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 proposals have been made to calculate the systolic blood pressure and the diastolic blood pressure using only appropriate pulse waves (see Patent Document 2 and Patent Document 3).

Japanese Examined Patent Publication No. 3-62088 Japanese Patent Publication No. 5-32053 Japanese Unexamined Patent Publication No. 7-39529

  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. When there was a large body movement, the reliability of the measurement result was low.

  Therefore, if abnormal data or noise is detected during measurement, the measurement result is displayed or alerted with a warning sound, etc. so that the measurement subject can recognize that the reliability of the measurement result is low, and remeasure Can be encouraged. However, abnormal data and noise during measurement are not only those that have a large effect on the measurement results, so if such notification is frequently made, it is bothersome for the subject and the reliability of the electronic sphygmomanometer itself There was a problem that could lead to doubts.

  The present invention has been made to solve such a problem, and even if abnormal data or noise that does not greatly affect the measurement result during measurement is present, the measurement result is not notified. An object of the present invention is to provide an electronic sphygmomanometer that notifies only when a body movement that has a great influence is detected and prompts remeasurement.

  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 the pressurization and depressurization. Control means, pressure sensor for detecting the pressure in the cuff, pulse wave detection means for detecting a pulse wave component included in an output signal of the pressure sensor, and blood pressure calculation means for calculating blood pressure from the pulse wave component Noise separation storage means for determining noise included in the pulse wave component and storing the noise peak value as a noise value separately from a normal pulse wave peak value, and a maximum of the stored noise values Body motion detecting means for comparing the noise value with the maximum peak value and detecting the maximum noise as body motion when there is a difference or ratio greater than a certain value is provided.

  The pulse wave detecting means is included in the output signal of the pressure sensor while the inside of the cuff is being pressurized by the pressurizing means, or after being pressurized to a predetermined pressure and the inside of the cuff is being decompressed by the pressure reducing means. It is desirable to detect the pulse wave component.

  Similarly to the conventional electronic sphygmomanometer, blood pressure calculation means for calculating the highest blood pressure and the lowest blood pressure based on the maximum peak value of the normal pulse wave, and the highest blood pressure and the lowest blood pressure calculated by the blood pressure calculation means. It is possible to appropriately provide display means for displaying.

  Furthermore, it is desirable to provide a body motion notifying means for notifying when a body motion is detected by the body motion detecting means. However, blood pressure measurement may be interrupted without notifying when body movement is detected.

  The noise separation storage means sequentially compares the peak values of a plurality of pulse waves with each other, and determines that a peak value having a difference or ratio greater than or equal to a predetermined value with respect to other peak values is noise and determines the peak value. It may be a means for storing as a noise value and storing other peak values as the peak value of a normal pulse wave.

  The electronic sphygmomanometer further includes a differentiating unit for differentiating the output signal of the pressure sensor while the inside of the cuff is being pressurized by the pressurizing unit, and a body movement determining unit for determining the presence or absence of body movement from the differential waveform. You may have.

  When the body motion notification means is provided, the display means for displaying the blood pressure measurement result is a means for displaying the presence of body motion in characters or graphics, or the sound, warning sound, lighting or blinking of a warning lamp, the display means It may be a means for notifying that there is a body movement by either blinking the display of the measurement result or changing the display color.

  The electronic sphygmomanometer according to the present invention makes it possible to accurately calculate blood pressure by excluding them even if abnormal data or noise is mixed in the pulse wave component detected during blood pressure measurement, and greatly affect the measurement result. Since a body movement is detected only when a noise is detected, re-measurement can be promoted by notifying the detection of the body movement or interrupting the measurement. As a result, body motion is frequently notified or measurement is interrupted, and the reliability of measurement accuracy is not impaired, and the reliability of blood pressure measurement is increased.

It is a block diagram which shows a structure common to each embodiment of the electronic blood pressure monitor by this invention. It is a wave form diagram which shows the example of the output signal (pressure detection signal) of the pressure sensor in the cuff pressure reduction by 1st Embodiment measured at the time of pressure reduction of the electronic blood pressure monitor by this invention. It is a diagram which shows the relationship between the pulse wave height of the pulse wave component contained in the output signal of the pressure sensor shown in FIG. 2, and the maximum blood pressure and the minimum blood pressure, and the noise component. It is a flowchart which shows the flow of the process of the measurement at the time of pressure reduction by the microcomputer 6 shown in FIG. It is a wave form diagram which shows the example of the output signal (pressure detection signal) of the pressure sensor by 2nd Embodiment measured at the time of pressurization of the electronic blood pressure monitor by this invention. It is a wave form diagram which similarly shows the differential waveform of the pressure detection signal. FIG. 6 is a diagram showing the relationship between the pulse wave height of the pulse wave component included in the output signal of the pressure sensor shown in FIG. 5 and the maximum blood pressure and the minimum blood pressure, and the noise component. It is a flowchart which shows the flow of the process of the measurement at the time of pressurization by the microcomputer 6 shown in FIG.

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

[Configuration common to each embodiment]
First, the configuration common to the embodiments of the 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 a 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. The system includes an A / D converter 5, a microcomputer 6, operating means 7, display means 8, and body movement notifying means 9. 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 through the tube 12 at a constant speed, and 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 measuring the blood pressure during decompression, when a measurement start button (not shown) of the operating means 7 is pressed, the pressurizing pump of the pressurizing means 2 is operated to send air into the cuff 1 relatively quickly. When the pressure in the cuff 1 detected by the pressure sensor 4 reaches a predetermined value, the pressure 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 at a substantially constant speed by the rubber exhaust valve. 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.

  When the blood pressure is measured during pressurization, when the measurement start button of the operation means 7 is pressed, the pressurization pump of the pressurization means 2 is operated, and the pressure value in the cuff 1 detected by the pressure sensor 4 is determined. The cuff 1 is controlled to be pressurized at a constant speed. When the pressure in the cuff 1 detected by the pressure sensor 4 reaches a predetermined value, the pressurizing pump is stopped, the rapid pressure reducing valve of the pressure reducing means 3 is fully opened, and the air 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.

  The body movement notifying means 9 is a means for notifying the body movement when the memory / calculating means 10 of the microcomputer 6 is detected. Please fix it, "make a warning sound with an electronic buzzer, or turn on or blink a warning lamp. Alternatively, the display means 8 can also be used to display “with body movement” on the display means 8 with characters or figures (marks), blinking the display of the highest blood pressure and the lowest blood pressure as measurement results, It may be displayed in a different color.

  The function of the storage / calculation means 10 by the microcomputer 6 is that the output signal of the pressure sensor 4 is digitized and input via an A / D converter as shown in FIG. Pulse wave detection means 13 for detecting a wave component and noise separation storage means for determining noise contained in the pulse wave component and storing the noise peak value as a noise value separately from the normal pulse wave peak value 14, blood pressure calculation means 15 for calculating the maximum blood pressure and the minimum blood pressure based on the maximum value of the normal pulse wave stored in the noise separation storage means 14, and the maximum noise among the noise values stored in the noise separation storage means 14 It has a function of body motion detection means 16 that detects a body motion when there is a difference or ratio of a certain value or more by comparing the value with the maximum peak value.

  The pulse wave detection means 13 detects the pulse wave component during the decrease of the pressure signal input via the A / D converter when measuring the blood pressure during decompression, and A / D when measuring the blood pressure during pressurization. A pulse wave component is detected during the rise of the pressure signal input through the converter.

  The systolic blood pressure and the diastolic blood pressure calculated by the blood pressure calculating means 15 are displayed by the display means 8, and when body motion is detected by the body motion detecting means 16, the body motion notifying means 9 is notified.

[First Embodiment]
Therefore, first, as a first embodiment of the present invention, an embodiment for measuring at the time of depressurization in the cuff 1 will be described with reference to FIGS.

  In this embodiment, as described above with reference to FIG. 1, when the measurement start button of the operating means 7 is pressed, the pressurizing pump of the pressurizing means 2 is operated to send air into the cuff 1 and apply relatively quickly. When the pressure in the cuff 1 detected by the pressure sensor 4 reaches a predetermined value, the pressure pump is stopped. Thereafter, the pressure in the cuff 1 is reduced at a constant speed by the decompression means 3.

When the pressure in the cuff 1 reaches a predetermined value, the blood flow is stopped by pressing the blood vessel of the arm of the measurement subject, and then the blood flow is restored and the artery pulsates when the pressure is relaxed. A pulsation phenomenon (pulse wave) that is superimposed on the internal pressure and synchronized with the heartbeat appears. The onset of the pulsation is small, becomes larger as the pressure is reduced, and eventually becomes smaller after showing the maximum amplitude.

  FIG. 2 is a waveform diagram showing an example of a pressure detection signal that is an output signal of the pressure sensor 4 during the decompression in the cuff. In FIG. 2, the horizontal axis represents time [sec], and the vertical axis represents pressure [mmHg]. The pressure in the cuff decreases at a constant rate with time as indicated by a straight line L1, but a pressure increase due to pulsation occurs periodically. This is called a pulse wave Ps. In addition, when the subject moves such as moving his arm or finger or coughing, a large pressure change Pn occurs.

  FIG. 3 shows each pulse wave (including noise components such as body motion) detected by the pulse wave detection means 13 shown in FIG. 1B from the pressure detection signal shown in FIG. The horizontal axis in FIG. 3 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. 3, the pulse wave height is small when the pressure in the cuff is high, increases as the pressure decreases, shows a maximum wave height value, and then decreases again. However, a noise component such as body movement is detected as a pulse wave having an abnormal peak value as indicated by Pn and Pm.

  The noise separation storage means 14 shown in FIG. 1B determines the noise included in the pulse wave component shown in FIG. 3 and uses the noise peak value as the noise value to distinguish the normal pulse wave peak value. Store separately. Various methods for determining the noise have been used in the past, but the simplest method is that when the peak value of the pulse wave next to a certain pulse wave is greater than or equal to a predetermined ratio (for example, 2 or 3 times), The pulse wave is determined as noise.

  Alternatively, in order to reduce the influence of the measurement error of the peak value of the pulse wave, the average of the peak values of a plurality of pulse waves (for example, three pulse waves and four pulse waves) is sequentially shifted by one pulse wave. The noise may be determined. In this case, the peak values of a plurality of pulse waves to be averaged are compared with each other, and pulse waves having a predetermined ratio (for example, twice or three times) or more are detected as noise. It is good to judge. In FIG. 3, white circles indicate the peak values obtained by shifting the pulse waves one by one and averaging the three pulse waves sequentially.

  In addition, if the upper and lower limits of the peak value of the next pulse wave are determined at a predetermined ratio with respect to the peak value of a certain pulse wave, and the next pulse wave is a peak value outside that range, it is determined within a certain time. The determination may be made by any method, for example, when there is a fluctuation greater than the value, or when the difference from the average value of the peak values of the preceding and succeeding pulse waves is greater than or equal to a predetermined value. In FIG. 3, the pulse waves Pm and Pn are both judged to be noise because their peak values are more than twice the peak value of the previous pulse wave, and each normal pulse wave is regarded as a noise value. This is stored separately from the crest value.

  The blood pressure calculation means 15 shown in FIG. 1B determines the maximum peak value among the peak values of normal pulse waves excluding the pulse waves Pm and Pn. In the example of FIG. 3, the peak value Hmax of the pulse wave Pmax is determined. Is determined as the maximum peak value. Then, the maximum pulse height value Hmax is multiplied by 50% in this example as a predetermined ratio α, and the higher pulse wave start pressure corresponding to the peak value of Hmax × 50% obtained in this example, about 123 mmHg in the example of FIG. (SYS), and the maximum pulse height value Hmax is multiplied by 70% in this example as a predetermined ratio β. In this example, the lower pulse wave start pressure corresponding to the peak value of Hmax × 70%, in the example of FIG. 108 mmHg is calculated as the minimum blood pressure (DIA).

In this way, the maximum blood pressure and the minimum blood pressure calculated by the blood pressure calculation unit 15 are displayed on the display unit 8.

  The body motion detection means 16 shown in FIG. 1B compares the maximum noise value Pn of the noise values Pm and Pn stored in the noise separation storage means 14 with the maximum peak value Hmax, and is equal to or greater than a certain value. When there is a difference or ratio, it is detected as body movement. For example, when Pn is twice or more than Hmax, the noise value Pn is detected as body movement when it is detected as body movement. At this time, when Pn is larger than Hmax by 5 mmHg or more, it may be detected as body movement. The detection of this body movement is notified by the body movement notification means 9, but may be notified by displaying a body movement mark on the display means 8.

  Since such processing is performed by the microcomputer 6 shown in FIG. 1A, the flow of measurement processing during decompression 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 S2. Pressurize until the value is reached and stop pressurization.

  After that, pressure reduction in the cuff 1 is started in step S3, a pulse wave is detected in step S4 while reducing pressure at a constant speed, it is determined whether or not it is noise in step S5, and if it is not noise, the wave is detected in step S6. The high value is stored as measurement data, and if it is noise, the peak value is stored as a noise value in step S7.

  When the measurement data is acquired, the maximum peak value Hmax is determined from the peak value stored as the measurement data in step S8, and the maximum blood pressure (SYS) and the minimum blood pressure (DIA) are calculated in step S9 as described above with reference to FIG. Steps S4 to S9 are repeated until it is determined in step S10 that the blood pressure value calculation has been completed.

  Here, the end of the blood pressure value calculation in step S10 is that after both the systolic blood pressure and the diastolic blood pressure can be calculated in step 9, the processing in steps S4 to S9 is further repeated to acquire pulse waves for several beats. The determination is made based on whether or not the pulse wave having the maximum peak value Hmax is detected.

  At this time, if a pulse wave having a maximum peak value Hmax is detected from pulse waves for several beats, the maximum peak value Hmax is updated in step 8 to recalculate the maximum blood pressure and the minimum blood pressure. If the maximum peak value Hmax is not updated, it is determined that the blood pressure value calculation is finished. The end of blood pressure value calculation in step S10 may be determined only by whether or not both the maximum blood pressure and the minimum blood pressure have been calculated in step S9.

  Thus, without continuing to detect the pulse wave until the pulse wave can no longer be obtained, the end of the measurement is judged at the time when the maximum blood pressure and the minimum blood pressure are calculated, and the cuff is quickly exhausted, so that the arm of the subject is measured. The time for pressing can be shortened.

  Next, the maximum noise value Pn stored as the noise value in step S11 is compared with the maximum peak value Hmax. If there is no difference of a certain value or more, the process proceeds to step S13 without detecting body movement, and the measurement result. The maximum blood pressure and the minimum blood pressure are displayed on the display means 8. If there is a difference greater than a certain value, body movement is detected in step S12, and in step S13, the maximum blood pressure and minimum blood pressure, which are measurement results, are displayed on the display means 8, and a body movement mark is displayed to indicate body movement. Announce that there was. Finally, in step S14, the air in the cuff 1 is rapidly exhausted to finish the pressure reduction, and the measurement process ends.

  The difference greater than a certain value determined in step S11 is, for example, the maximum noise value Pn is twice or more the maximum peak value Hmax, but the difference or ratio value can be changed as appropriate.

  The body motion notifying means 9 for notifying the body motion also displays the “with body motion” as a character or a figure (mark) using the display means 8, or turns on or blinks a voice, a warning sound, or a warning lamp. Various means such as blinking the display of the measurement result by the display unit 8 or displaying the measurement result in a color different from that in the normal state can be adopted.

[Second Embodiment]
Next, as a second embodiment of the present invention, an embodiment in which measurement is performed during pressurization in the cuff 1 will be described with reference to FIGS.

  In this embodiment, as described above with reference to FIG. 1, when the measurement start button of the operation means 7 is pressed, the pressure pump in the pressure means 2 is operated and the pressure in the cuff 1 detected by the pressure sensor 4 is operated. Depending on the value, the cuff 1 is controlled to be pressurized at a constant speed. When the pressure in the cuff 1 detected by the pressure sensor 4 reaches a predetermined value, the pressurizing pump is stopped, the rapid pressure reducing valve of the pressure reducing means 3 is fully opened, and the air in the cuff 1 is rapidly exhausted.

  Also in this case, a pulsation phenomenon (pulse wave) synchronized with the heartbeat appears in the pressure in the cuff, and is initially small, increases with pressurization, and finally decreases after showing the maximum amplitude.

  FIG. 5 is a waveform diagram showing an example of an output signal (pressure detection signal) of the pressure sensor when the electronic sphygmomanometer is pressurized. The pulse wave Ps shown in this figure is a pulse wave due to normal blood flow, but N1 and N2 are noises due to body movements and the like.

  FIG. 6 shows a differential waveform obtained by differentiating the pressure detection signal shown in FIG. 5 in order to determine such noise. In this differential waveform, a waveform that shows an amplitude with a large negative relative to positive, such as the waveform N1, can be determined as body movement. In this embodiment, the pressure input through the A / D converter 5 to the storage / calculation unit 10 of the microcomputer 6 shown in FIG. A function of differentiation means for differentiating the output signal (pressure detection signal) of the sensor 4 and body movement determination means for determining the presence or absence of body movement from the differentiated waveform is also provided.

  However, a waveform having an amplitude such as the waveform N2 in FIG. 6 is difficult to distinguish from a normal waveform and cannot be determined as body movement.

  FIG. 7 shows each pulse wave (including noise components such as body motion) detected by the pulse wave detection means 13 shown in FIG. 1B from the pressure detection signal shown in FIG. In FIG. 7, the horizontal axis represents the pulse wave start pressure [mmHg] when each pulse wave starts to rise, and the vertical axis represents the pulse wave height (wave height value) [mmHg]. As shown in FIG. 7, the pulse wave height is small when the pressure in the cuff is low, increases with increasing pressure, decreases again after showing the maximum wave height value. However, a noise component such as body movement is detected as a pulse wave having an abnormal peak value as indicated by Pn.

  Therefore, the noise separation storage unit 14 shown in FIG. 1B determines the noise contained in the pulse wave component shown in FIG. 7, and uses the peak value of the noise as the noise value to obtain the normal pulse wave peak value. Is memorized separately. Various methods for determining the noise have been conventionally performed in the same manner as described in the above embodiment, but the simplest method is that the peak value of a certain pulse wave is higher than the peak value of the pulse wave before and after the pulse wave. If the ratio is greater than or equal to a predetermined ratio (for example, twice or three times), the pulse wave is determined as noise.

In FIG. 7, the pulse wave Pn is determined to be noise because its peak value is more than twice the peak value of the next pulse wave, and the peak value of the other normal pulse wave is determined as the noise value. Is memorized separately.

  Alternatively, in this embodiment as well, the average of the peak values of a plurality of pulse waves (for example, three pulse waves and four pulse waves) is shifted one by one and sequentially taken to determine noise as in the above example. In that case, if the peak values of a plurality of pulse waves to be averaged and the average value thereof are compared with each other, a pulse wave having a predetermined ratio (for example, twice or three times) or more is determined as noise. Good. In FIG. 7, white circles indicate the peak values obtained by shifting one pulse wave at a time and sequentially averaging three pulse waves.

  The blood pressure calculation means 15 shown in FIG. 1B determines the maximum peak value among the peak values of the normal pulse wave excluding the noise pulse wave Pn. In the example of FIG. 7, the peak value Hmax of the pulse wave Pmax is determined. Is determined as the maximum peak value. Then, the maximum pulse height Hmax is multiplied by 50% in this example as a predetermined ratio α, and the higher pulse wave start pressure corresponding to the peak value of Hmax × 50% obtained in this example, about 115 mmHg in the example of FIG. (SYS), and the maximum pulse height value Hmax is multiplied by 70% in this example as a predetermined ratio β. In this example, the lower pulse wave starting pressure corresponding to the peak value of Hmax × 70%, in the example of FIG. 78 mmHg is calculated as the diastolic blood pressure (DIA).

  In this way, the maximum blood pressure and the minimum blood pressure calculated by the blood pressure calculation unit 15 are displayed on the display unit 8.

  The body motion detection means 16 shown in FIG. 1B compares the maximum noise value Pn of the noise values stored in the noise separation storage means 14 with the maximum peak value Hmax, and a difference or ratio greater than a certain value. When there is, it detects as body movement. For example, when Pn is larger than Hmax by 5 mmHg or more, the noise value Pn is detected as body movement. At this time, if Pn is twice or more of Hmax, it may be detected as body movement. The detection of this body movement is notified by the body movement notification means 9, but may be notified by displaying a body movement mark on the display means 8.

  By detecting the body movement in this manner, the body movement can be detected even when the body movement cannot be detected only from the differential waveform obtained by differentiating the pressure detection signal.

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

  Measurement is started by turning on the measurement start button of the operation means 7, and pressurization in the cuff 1 is started in step S21, and the pressure in the cuff is increased at a substantially constant speed as shown in FIG.

  Then, the pulse wave is detected in step S22, and it is determined whether or not it is noise in step S23. If it is not noise, the peak value is stored as measurement data in step S24, and if it is noise, the peak value is determined in step S25. Is stored as a noise value.

  When the measurement data is acquired, the maximum peak value Hmax is determined from the peak value stored as the measurement data in step S26, and the maximum blood pressure (SYS) and the minimum blood pressure (DIA) are calculated in step S27 as described above with reference to FIG. Steps S22 to S24 or S25 are repeated until it is determined in step S28 that the blood pressure value has been calculated.

  Here, when the calculation of the blood pressure value in step S28 is completed, after both the systolic blood pressure and the diastolic blood pressure can be calculated, the processing in steps S22 to S27 is further repeated to acquire pulse waves for several beats, and the maximum wave The determination is made based on whether or not a pulse wave having a high value Hmax is detected (the maximum peak value Hmax is updated).

  The end of the blood pressure value calculation in step S28 may be determined only by whether or not both the maximum blood pressure and the minimum blood pressure have been calculated in step S27. The reason for this is the same as that described in the above embodiment.

  Next, the maximum noise value Pn stored as the noise value in step S29 is compared with the maximum peak value Hmax. If there is no difference of a certain value or more, the process proceeds to step S31 without detecting body movement, and the measurement result. The maximum blood pressure and the minimum blood pressure are displayed on the display means 8. If there is a difference greater than a certain value, body movement is detected in step S30, and the maximum blood pressure and minimum blood pressure as measurement results are displayed on the display means 8 in step S31. Announce that there was.

  The difference greater than or equal to the predetermined value determined in step S29 is, for example, that the maximum noise value Pn is 5 mmHg or more larger than the maximum peak value Hmax, but may be determined by a ratio, and the maximum noise value Pn may be determined by the maximum peak value Hmax. The value can be changed as appropriate, such as 2 times or more.

  Finally, pressurization is terminated in step S32, and the air in the cuff 1 is rapidly exhausted to complete the measurement process. Various means can be adopted as means for notifying body movement as described above.

  According to any of the above-described embodiments of the electronic sphygmomanometer according to the present invention, even if abnormal data or noise is mixed in a pulse wave component detected during blood pressure measurement, the blood pressure is accurately calculated by excluding them. Can be displayed. Then, only when a body movement that greatly affects the measurement result is detected, it can be notified to prompt remeasurement. Therefore, since slight body movements and noises are frequently reported and the reliability of measurement accuracy is not impaired, body movements are reported only when remeasurement is really necessary. It is also possible to prevent recording as it is.

  However, a feature of the present invention is that it accurately detects body movements that may seriously affect the measurement results among noise components mixed in the pulse wave detected during blood pressure measurement. Each of these means is essential for the present invention.

  Note that the magnitude of the difference or ratio for detecting body motion can be arbitrarily changed, whereby the body motion detection sensitivity can be easily adjusted.

  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 9: Body motion notifying means 10: Storage / calculating means 11: Control means 12: Tube 13: Pulse wave detection means 14: Noise separation storage means 15: Blood pressure calculation means 16: Body motion detection means

Claims (4)

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;
Pulse wave detection means for detecting a pulse wave component included in the output signal of the pressure sensor;
Blood pressure calculating means for calculating blood pressure from the pulse wave component;
Noise separation storage means for determining noise contained in the pulse wave component and storing the noise peak value as a noise value separately from the normal pulse wave peak value;
Body motion detection means for comparing the maximum noise value of the stored noise values with the maximum pulse height value of a normal pulse wave and detecting the maximum noise value as body motion when there is a difference or ratio greater than a certain value When,
An electronic blood pressure monitor, comprising:   The noise separation storage means sequentially compares the peak values of a plurality of pulse waves with each other, and determines that a peak value having a difference or ratio greater than or equal to a predetermined value with respect to other peak values is noise and determines the peak value. The electronic sphygmomanometer according to claim 1, wherein the electronic sphygmomanometer is stored as a noise value, and the other peak values are stored as a normal pulse wave peak value.   It has body motion notifying means for notifying when body motion is detected by the body motion detecting means, and the body motion notifying means is means for displaying the detection of body motion in characters or graphics. The electronic blood pressure monitor according to claim 1 or 2, characterized in that A body motion notifying means for notifying the body motion when the body motion is detected by the body motion detecting means;
The body motion notifying means is means for notifying detection of body motion by any one of voice, warning sound, lighting or flashing of a warning lamp, flashing of display, or change of display color. 2. The electronic blood pressure monitor according to 2.