JPH0489029A - Blood pressure measuring device - Google Patents

Abstract

PURPOSE:To assume the cause that no correct blood pressure measurement can be performed by detecting the peaks of pulse waves based on the output of a pressure sensor, and displaying the time interval of the peaks of the pulse waves. CONSTITUTION:A pressure sensor 11 detecting the inner pressure of the air bag of an arm band, a high-pass filter HPF 12 extracting the pulse wave component from the output, a peak detecting circuit 13 detecting the peaks of pulse waves, a counter 14 reset synchronously with the peak detection, a driver circuit 15 driving a pulse wave interval display section 16 based on the count value, and the pulse wave interval display section 16 displaying the time interval of the peaks of the pulse waves are provided. Clocks are fed to the counter 14 and driver circuit 15 via a terminal 17 and displayed in response to the count value of the counter 14. The pulse wave interval display section 16 displays the time interval of the peaks of the pulse waves, and the time interval is visually recognized.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Application Field The present invention relates to a blood pressure measuring device, and particularly to a blood pressure measuring device that has a blood pressure measuring function as well as a function of detecting and displaying the time interval of pulse wave peaks. Regarding equipment.

C8 Prior Art As a method for measuring blood pressure, for example, the oscillometrics method is known, in which blood flow is controlled by pressurizing an air bladder in a cuff, and blood pressure is measured by detecting pressure changes in the air bladder. . A blood pressure measuring device using this oscillometrics method (hereinafter referred to as a blood pressure monitor) was developed by the applicant, for example, in Japanese Patent Application No.
This is proposed in the specification, drawings, etc. of No. 25311.

With a blood pressure monitor using the oscillometric method, the distance is 4 m during measurement.
For example, when an arrhythmia occurs, when the pulse rate is extremely high or low, or when the pressure sensor detects noise due to body movement, it becomes impossible to accurately measure blood pressure.

By the way, arrhythmia and abnormalities in pulse wave frequency can be detected using electrocardiographs and pulse rate monitors, but it is economically difficult to bring such devices into the home.

Therefore, in conventional home blood pressure monitors, when accurate measurements cannot be taken, the measurement result is displayed as is, or a message indicating a measurement error is displayed. It also measures again and displays the results of the remeasurement.

For this reason, the person measuring the blood pressure cannot determine the reason for not being able to measure blood pressure accurately using the above-mentioned display.
There is a risk of misjudgment that the blood pressure monitor is malfunctioning.

D9 Problems to be Solved by the Invention By the way, some conventional blood pressure monitors have a function of emitting, for example, a buzzer sound in synchronization with pulse wave detection during blood pressure measurement, and some have a function of emitting, for example, a buzzer sound in synchronization with pulse wave detection. Some devices have a function of displaying a pulse wave detection mark on the display section. Therefore, a method can be considered that uses these functions to constantly observe the interval between buzzer sounds, and when the interval is disturbed, it is known that an abnormality has occurred in the pulse wave. However, with this method, the measurer must concentrate his or her energy in a quiet place to observe the interval between the buzzer sounds, which is difficult in practice.

The present invention has been made in view of the above-mentioned problem G, and is capable of displaying pulse wave intervals so that they can be easily known.
An object of the present invention is to provide a blood pressure measuring device capable of estimating the cause of failure to accurately measure blood pressure.

89 Means for Solving the Problems In order to solve the above problems, the present invention controls blood flow by pressurizing an air bladder in the cuff, detects pressure changes in the air bladder with a pressure sensor, and measures blood pressure. In the blood pressure measuring device for measuring blood pressure, a peak detection means detects the peak of the pulse wave based on the output of the pressure sensor, and a display means displays the time interval between the peaks of the pulse wave according to the output of the peak detection means. It is characterized by having the following.

The display means for displaying the time interval between the peaks of the pulse wave may be, for example, a so-called heart graph display section in which a plurality of display segments are arranged in one direction, in which a portion corresponding to the peak moves or a peak hold display is performed. By this,
A display device that allows the temporal interval of pulse wave peaks to be visually recognized can be used.

F9 Effect In the blood pressure measuring device according to the present invention, the peak detection means detects the peak of the pulse wave, and the time interval between the peaks of the pulse wave is displayed on the display means in accordance with the output of the peak detection means.

G. Example Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram of the essential parts of a blood pressure measuring device (hereinafter referred to as a blood pressure monitor) according to a first embodiment of the present invention, and FIG. 2 is an external view of the entire blood pressure monitor.

First, the entire blood pressure monitor will be explained.

For example, as shown in FIG. 2, the blood pressure monitor includes a main body 2 and a cuff 3, and the main body 2 and cuff 3 are connected by an air hose 4.

The main body 2 is provided with a display section 5 made of, for example, a liquid crystal display on the front side, and a switch 6a for setting a pressurization value that is 30 to 40 mmHg or more higher than the expected systolic blood pressure value of the person taking the measurement, for example, and a switch 6a for blood pressure measurement. switch 6b to start
An operating section 6 consisting of the like is provided at the top.

When the measurer operates the switch 6a to set the pressurization value, wraps the cuff 3 around his arm, rests, and operates the switch 6b, blood pressure measurement starts, and the measurement results etc. are displayed on the display 5. is now displayed.

Specifically, air is sent through the knee hose 4 to an air bag (not shown) provided inside the cuff 3 by, for example, an air pump (not shown) provided inside the main body 2, and, for example, As shown in FIG. 3A, the internal pressure of the air bag is rapidly increased to the above-mentioned set value, and then gradually reduced. During this pressure reduction, the so-called oscillometric method is used, in other words, the cuff 3 is wrapped around the air bag. A pressure sensor detects slight fluctuations in the internal pressure of the air bladder caused by a hemangioma in the arm, measures the systolic blood pressure and diastolic blood pressure, and displays these measurement results on the display section 5.

In the sphygmomanometer having the blood pressure measurement function as described above, in addition to the blood pressure measurement function, the present invention has a function of detecting and displaying the time interval of pulse wave peaks, and is capable of detecting the above-mentioned arrhythmia during blood pressure measurement. This allows you to know the occurrence of heart failure, abnormalities in pulse wave frequency, etc.

Specifically, as shown in FIG. 1, for example, a pressure sensor 11 that detects the internal pressure of the air bladder of the arm cuff, and a bypass filter (hereinafter referred to as HPF) that extracts a pulse wave component from the output of the pressure sensor 11 are used. ) 12, a peak detection circuit 13 that detects the peak of the pulse wave from the 1HPF 12, a counter 14 that is reset in synchronization with the peak detection of the peak detection circuit 13, and a pulse wave detection circuit 14 that detects the pulse wave based on the count value of the counter 14. It is equipped with a driver circuit 15 that drives the interval display section 16 and the pulse wave interval display section 16 that displays the time interval between pulse wave peaks. The display is made in accordance with the count value of the counter ]4.

The pulse wave interval display section 16 is provided, for example, as shown in FIG. 4, in a part of the display section 5 shown in FIG. It is a so-called half graph display, which displays the time interval of the peak of the pulse wave, like a so-called level indicator with peak hold used in tape recorders, etc., and allows you to visually recognize the time interval. It is now possible to do so.

Next, the operation of the apparatus having the above configuration will be explained.

As shown in Figure 3B, the pulse wave from the HPF 12 has a waveform in which the amplitude increases as the pressure decreases from the time the pressure begins to decrease, and the amplitude decreases as the pressure decreases when the internal pressure of the air bladder falls below a certain value. becomes. Then, the peak detection circuit 13 detects the peak (mountain) of the pulse wave and sends, for example, a high level (hereinafter referred to as H level) to the counter 14. The counter 14 is reset by the H level output of the peak detection circuit 13.

That is, the count value of the counter 14 takes a large value when the time interval between pulse wave peaks is wide, and conversely takes a small value when the time interval between pulse wave peaks is narrow.

The driver circuit 15 then outputs a counter 14 for each beat.
The length of the level indicator on the pulse wave interval display section 16, that is, the blinking of each segment of the level indicator (blocking or transmitting state of the liquid crystal) is controlled according to the count value of Make sure to leave it lit.

Specifically, the pulse rate within the measurement range of a normal blood pressure monitor is 40~
In order to effectively display the highest 200 beats/minute, the cycle of the clock supplied to the counter 14 is set to 0.15 (=1 ÷ (200 ÷ 60) ÷ 2) seconds, corresponding to approximately 200 beats/minute. In addition to resetting the counter 14 in synchronization with the detection of the peak of the pulse wave, the driver circuit 15 operates as shown in FIG. 5A, for example.
As shown in the figure, the leftmost segment of the pulse wave interval display section 16 is controlled to be lit (indicated by a square in the figure). Then, the counter 14 performs count amplification at a cycle of 0.15 seconds until the next peak of the pulse wave is detected, and as shown in FIG. control so that they light up sequentially.

Next, when the next pulse wave peak is detected, counter 1
For example, as shown in FIG. Control. Then, until the next peak of the pulse wave is detected, the adjacent segments are controlled to be lit in sequence according to the count value of the counter 14, for example as shown in Figure 5. As a result, the time interval of pulse wave peaks can be directly read during blood pressure measurement, and
Since the time interval of the previous pulse wave peak remains, changes in the interval can be easily detected.

By the way, the time interval t of the peak of the pulse wave, that is, the peak, is the same interval when normal measurement is performed, but
For example, if you move your arm during measurement, noise enters the pressure sensor 11, and as shown in FIG. . Furthermore, when an arrhythmia occurs, for example, as shown in FIG. 3B, the time interval t between the pulse wave peaks becomes t.
It will be different like 1□.

Therefore, for example, during measurement, you may notice, ``You moved your arm a little.''
In such a case, if you check the pulse wave interval display section 16 for an abnormality in the time interval between the peaks of the pulse wave, if the blood pressure measurement result is a strange value, it will be possible to check if the pulse wave interval display section 16 shows an abnormality in the time interval between pulse wave peaks.
It is possible to infer that this is the cause. Furthermore, for example, if the pulse wave peaks are detected at different time intervals even though the patient is quiet during the measurement, it can be determined that "an arrhythmia is occurring." moreover,
It can be seen that the pulse is changing rapidly when the illuminated segment that is held for each pulse moves rapidly.

In addition, as shown in Figure 5, by displaying the range of pulse wave numbers in which blood pressure can be measured as the measurable range above the level indicator, it is possible to check whether the current pulse wave number is within the above range during measurement. You can find out more easily.

Next, a second example will be described.

In this embodiment, as shown in FIG. 6, instead of the counter 14, driver circuit 15, and pulse wave interval display section 16 shown in FIG. 26 is used.

Specifically, the shift register 24 is configured to store, for example, a pulse wave peak time interval of about 3 beats.
It consists of a shift register consisting of stages, and is adapted to shift the output of the peak detection circuit 13 using a clock with a period of 15 seconds supplied via a terminal 17. That is, when the pulse wave peak is detected, the H level is supplied to the shift register 24 and shifted, and the L level is supplied to the shift register 24 and shifted until the next pulse wave peak is detected. .

Further, the pulse wave interval display section 26 is provided, for example, in a part of the display section 5 shown in FIG. 2, as in the above-described first embodiment. For example, it is made up of 30 segments that can display the time interval of pulse wave peaks of about 3 beats, and each segment is turned on or off under the control of the driver circuit 25.

Further, the driver circuit 25 controls lighting of each segment of the pulse wave interval display section 26 in accordance with the parallel output of the shift register 24. Specifically, for example, the leftmost segment of the pulse wave interval display section 26 corresponds to the first stage of the shift register 24, and the adjacent segments correspond to the subsequent stages, for example, as shown in FIG. In response to the shift of the H level in the register 24, the lighting segments are sequentially scrolled to the right (
movement).

In this way, the time interval between pulse wave peaks can be directly read during blood pressure measurement, and the cause of inaccurate blood pressure measurement results, such as the occurrence of arrhythmia or physical activity, can be inferred. Additionally, abnormalities in pulse wave frequency can be detected. Furthermore, since the time interval between pulse wave peaks is displayed as three beats, changes in the interval can be easily seen.

As described above, in the present invention, by detecting the peak of the pulse wave based on the output of the pressure sensor and displaying the time interval between the peaks of the pulse wave, the time interval between the peaks of the pulse wave can be directly read. When the meter displays, for example, an inaccurate measurement result or an error message, or when it re-measures and displays the measurement result, it is possible to infer the cause, for example, the occurrence of an arrhythmia, an abnormality in the pulse wave frequency, etc.

Further, the circuit configuration for detecting pulse wave peaks and displaying the time intervals between the peaks is simple and inexpensive, as shown in FIGS. 1 and 6 above. Therefore, the present invention can also be applied to home blood pressure measuring devices.

Note that the present invention is not limited to the above embodiments,
For example, the number of stages of the shift register 24 shown in the sixth section may be set to 13 so that the pulse wave peak detection status during the blood pressure measurement time excluding the pressurization time, for example, 20 to 30 seconds, can be stored.
0 to 200 steps, and during blood pressure measurement, the time interval of the peak of the pulse wave is displayed in real time as shown in the above-mentioned Fig. 7, and after the measurement, the time interval between the peaks of the pulse wave is displayed as desired, for example from around the detection of systolic blood pressure to around the detection of diastolic blood pressure. may be selected and displayed.

Furthermore, after the measurement, it may be compressed in time and displayed in its entirety.

H1 Effects of the Invention As is clear from the above explanation, the present invention detects the peak of the pulse wave based on the output of the pressure sensor and displays the time interval between the peaks of the pulse wave. If the blood pressure monitor displays an inaccurate measurement result, an error message, or re-measures and displays the measurement result, you can easily find out the time interval between the blood pressure monitor and the cause, such as arrhythmia. It is possible to estimate abnormalities in pulse wave frequency, etc.

Further, since the circuit configuration of the present invention is simple and inexpensive, the present invention can be applied to home blood pressure measuring devices.

[Brief explanation of drawings]

FIG. 1 is a block circuit of the first embodiment of the blood pressure measuring device according to the present invention, FIG. 2 is an external view of the entire blood pressure measuring device, and FIG. HPF12
FIG. 4 is a diagram showing a display example of the display section 5 shown in FIG. 2, and FIG. 5 is a waveform diagram showing the relationship between the outputs of the pulse wave interval display section 16 shown in FIG. FIG. 6 is a block circuit of a second embodiment of the blood pressure measuring device according to the present invention, and FIG. 7 is a diagram for explaining a display method.
It is a figure which shows the example of a display of the pulse wave interval display part 26 shown in a figure. 11 ... Pressure sensor 13 ... Peak detection circuit 14 ... Counter 15 ... Driver circuit 16 ... Pulse wave interval display section 24 ... Shift register 25 ... Driver circuit 26...Pulse wave interval display section

Claims (1)

[Scope of Claims] A blood pressure measuring device that controls blood flow by pressurizing an air bladder in a cuff, and measures blood pressure by detecting pressure changes in the air bladder with a pressure sensor, What is claimed is: 1. A blood pressure measuring device comprising: a peak detecting means for detecting a peak of a pulse wave based on the pulse wave; and a display means for displaying a time interval between the peaks of the pulse wave according to an output of the peak detecting means.