JPS5975036A - Blood pressure measuring apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention reduces invasiveness to the subject and eliminates external noise.

This invention relates to a blood pressure measuring device that solves the problem of foot noise while taking into consideration the responsiveness of the living body.

With conventional ultrasonic blood pressure measuring devices, a cuff is wrapped around the upper arm, the cuff pressure is set at a position sufficiently higher than the blood pressure, and the pressure is gradually lowered to calculate the external pressure force when the Dotsuplar signal is generated as the systolic blood pressure (systolic blood pressure). The pressure is further lowered and the external pressurizing force when the signal disappears is taken as the diastolic blood pressure (Bresch diastolic pressure) and measured. In this way, the decompression rate is slow and the pressure is applied over a long period of time, resulting in invasive symptoms such as a feeling of pressure, fatigue in the arms, and tingling in the tips of the hands. Especially the Rakuchu Monitoring Facility (Eng Cσ).

Cardiac disease patients/monitoring equipment (CCTR), etc.
In the J monitoring system, measurements are taken several times, so
With this bifurcated device, which places a heavy burden on the patient, the measurement time is long, so there is a high probability that external noise will enter the blood pressure measurement transducer, and there is also a large foot-like noise caused by things other than the movement of the blood pressure wall. It is difficult to identify them because their frequency characteristics are the same. This is often seen near the systolic and diastolic blood pressures, and is especially a big problem near the diastolic blood pressure.

The present invention has been made in consideration of the above points, and an object of the present invention is to provide an apparatus that can reduce the invasiveness to a subject, is resistant to noise, and can measure blood pressure with high reliability.

First, we will describe a device for measuring systolic blood pressure that aims to rapidly change cuff pressure to perform invasive procedures to prevent external noise from entering and to make it easier to detect signals.

FIG. 1 shows the relationship among pressure pulse waves, blood pressure, cuff pressure, and Doppler signals. Rapidly pressurize to the initial pressure P at any time, wait for a predetermined time, then detect the presence or absence of a Doppler signal.After confirming that there is no signal due to an increase or decrease in the initial pressure, the rising 9-part molecule of the pressure pulse wave is detected. , the pressure is rapidly reduced exponentially based on , and a signal is detected. The cuff pressure at this time is defined as blood pressure. Based on this result, by reducing the width of the pressure reduction and repeating it in successive approximations, it becomes possible to measure without including errors due to the responsiveness of the living body.

FIG. 2 is a block diagram of the systolic blood pressure measuring device. In this figure 2, 8 is a ring, and 9 is a pressure pulse wave measurement converter 1.
0 is a converter for measuring Doppler signals, and the upper arm 11
It is installed in the position shown in the second figure. 1 is a Doppler signal detection device, 2 is a bandpass filter, 3 is a pressure pulse wave detection device, 4 is a pressure pulse wave waveform shaping circuit, 5 is a pressurization/decompression waveform forming circuit, and 6 is a converter for cuff pressure measurement. . 12 is a Doppler signal output terminal, and 13 is an output terminal of the cuff pressure measuring converter 6.

With such a configuration, the vibration of the cuff 8 is caused by rapidly pressurizing the cuff 8 using a pump at an arbitrary time of one heartbeat to a position sufficiently higher than the blood pressure set by the pressurization/decompression waveform forming circuit 5 for a predetermined period of time. (10 msec to 100111 BθC), and determines the presence or absence of the Doppler signal output from terminal 12. When a signal is detected, pressurize (plus 5 mHg)' until finally no signal is detected, and then convert. The output of the device 9 is detected by the pressure pulse wave detection device 3. After converting it into a trigger signal by the pressure pulse waveform shaping circuit 4, the pressure is reduced exponentially with a time setting of #0.18θC using this signal as a reference. At this time, the Doppler signal input to the converter 10 is
A certain frequency component is extracted by a bandpass filter 2 through a Doppler signal detection device 1 and detected at a terminal 12. Then, the first measurement is completed as the output 1 of the terminal 13 at the time when the signal corresponds to the person 6 - pseudo blood pressure. Next, based on this result, set the initial pressure for the second time, and set the initial pressure for the third time based on the result of the second time, and perform the same procedure as the first time.

The second initial pressure P1 is the pseudo blood pressure plus lOs+H
g s3rd P, plus 5 rrs Hg. In this way, the pressure reduction width is reduced three times in a successive approximation manner, and the third result is displayed as blood pressure, allowing measurement.

Next, a device for measuring diastolic blood pressure will be described, which aims to rapidly change cuff pressure to reduce v-strokes, prevent external noise from entering, and facilitate signal detection.

FIG. 3 shows the relationship between pressure pulse wave, blood pressure, cuff pressure, and Doppler signal. At an arbitrary time, the pressure is rapidly increased to the initial pressure P, and after waiting for a predetermined time, the presence or absence of the top 2 signal is detected.After confirming that there is a signal by increasing or decreasing the initial pressure, the rising part of the pressure pulse wave is detected. TI based on child
The signal is detected by rapidly decompressing the signal with an exponential delay. The cuff pressure at this time is defined as blood pressure. Based on this result, by reducing the width of the pressure reduction and repeating it in successive approximations, it becomes possible to measure without including errors due to the responsiveness of the living body.

FIG. 4 is a block diagram of the diastolic blood pressure measuring device. In this vJ4 diagram, 8 is a cuff, 9 is a pressure pulse wave measurement transducer, and JO is a dog 2 signal measurement transducer.
1, the device is placed in the position shown in the fourth figure. 1 is a Doppler signal detection device, 2 is a bandpass filter, 3 is a pressure pulse wave detection device, 4 is a pressure pulse wave waveform shaping circuit, 7 is a delay circuit, 5 is a pressurization waveform forming circuit, and 6 is for cuff pressure measurement. Use a converter. 12 is an output terminal of the Doppler signal, and 13 is an output terminal of the cuff pressure measuring converter 6.

With such a configuration, the vibration of the cuff can be controlled by rapidly increasing the pressure to a position sufficiently higher than the diastolic blood pressure set by the pressurization/decompression waveform forming circuit 5 by turning on the pump at an arbitrary time of one heartbeat. Wait for a time (lQmsec~100m5ec),
The presence or absence of the top 2 signal is determined by the output from the terminal 12, and if no signal is detected, pressurization (plus 5 degrees Hg) is applied until the signal is finally detected, and the output of the converter 9 is After the pressure pulse wave detection device 3 and the pressure pulse wave waveform shaping circuit 4 convert it into a trigger signal, the delay circuit 7 outputs the JT! (
The pressure is reduced exponentially with a delay of 500ml1llθC~8QQm8eO) and a time period of 70.1 seconds. At this time,
The top 2 signal input from converter 1() is
A signal detection device 1 passes through a bandpass filter 2 to pick up a constant frequency component and detects it at a terminal 12. Then, the first measurement is completed using the output of the terminal 13 at the time corresponding to the signal as a pseudo blood pressure. Next, based on this result, the second time.

Determine the initial pressure for the third time based on the results of the second time.1
Do it the same way as the first time. 21! -11th W phase pressure PR
is 10 tmHgs plus the simulated blood pressure.The third P is plus 5 mHg. In this way, it is possible to perform blood pressure measurement by successively approximating the pressure reduction while decreasing the width of the pressure reduction three times and displaying the third result as blood pressure.

This device performs three-circuit repeat measurements in a short period of 10 to 15 seconds by decreasing the decompression range between the initial value of the cuff pressure and the systolic or diastolic blood pressure by 5 mHg increments. Feeling of pressure.

Invasive effects such as numbness at the tips of two hands due to sluggish arms are alleviated, and the problem of the responsiveness of the living body to cuff correction, which occurs because the living body is a viscoelastic body, is also resolved.

In addition, since the cuff pressure reduction time is 200m8θC, the operating time of the converter for measuring the Dotsupler signal is 4 (1G-a = 83 Shizo--' Stripping
The probability that external noise (as short as oomsθC) will be mixed in is much smaller than in the conventional method.

00 Furthermore, regarding the problem of constant noise, the amplitude of the Doppler signal is proportional to the displacement of the blood V wall, and the frequency characteristic is also proportional to the movement speed of the blood vessel wall, so the cuff pressure reduction time is as short as 200 m5ec, and the signal amplitude is the highest and lowest. The multi-frequency characteristic, which has 10 times higher blood pressure than the conventional method, has a constant noise of 1 OHZ with a peak of 25 Hz.
While the signal is shown in a short range of ~1oOHz, the signal peaks at 250 Hz and has a wide range of 2.5Hz to 1KHz, making it possible to identify things that were previously impossible to identify by frequency analysis. solve.

As described above, if the difference width between the initial value of the cuff pressure and the blood pressure is reduced in a short time and the steps are repeated in successive approximations, the p1 invasion can be reduced, and the operating time of the Doppler signal measurement converter can be reduced. Since the distance is short, the probability of external noise being mixed in is reduced, and errors caused by the viscoelastic body of the living body are also eliminated. Also, the amplitude of the Doppler signal is proportional to the displacement of blood tm.
1L, since the frequency is proportional to the movement speed, the amplitude of the reverse signal 111 is large due to the rapid change in cuff pressure 't-, and the frequency characteristics are higher than the noise characteristics. The 8N ratio is improved by identifying noise. Therefore, the present invention enables blood pressure measurement that is resistant to noise and extremely minimally invasive.

[Brief explanation of drawings]

Figure 1 shows pressure pulse wave, blood pressure, square pressure, and doppjishin? 2 is a block diagram showing the configuration of the first embodiment of the device of the present invention, and FIG. 3 is a waveform diagram showing the relationship between pressure, pulse waves,
A waveform diagram showing the relationship between blood pressure, cuff pressure, and Doppler signal,
FIG. 4 is a block diagram showing the configuration of the second embodiment. 1...Dotsupura signal detection device, 2...
...Band pass filter, 3...
・Pressure pulse wave detection its 4...... Pressure pulse wave waveform shaping circuit, 5...... Pressure/decompression waveform forming circuit, 6...... Cuff pressure measurement converter, 7.
......Delay circuit, 8...Kan, 9......Pressure pulse wave measurement converter, 10.
......Dotsupura signal measurement converter, 11...
...... Upper arm, 12... Output terminal of Doppler signal, 13... Output terminal of cuff pressure measurement converter.

Claims (1)

[Claims] (Li) A cuff for measuring pressure a on the upper arm, and a converter attached to this cuff that detects a signal that detects changes in blood pressure due to heartbeat as a pulse wave and a signal that detects a certain time difference. , a downstream transducer that detects the downstream signal of blood a generated based on the movement of the blood vessel wall, and at any time of one heartbeat,
A means of rapidly supplying air to the cuff, pressurizing it, waiting for a predetermined period of time, and then rapidly depressurizing the cuff.The initial pressure of the cuff is increased or decreased, and there is a certain time difference between the signal and the signal that detects the change in blood pressure caused by the heartbeat as a pulse wave. When the cuff pressure is rapidly changed based on the signal, the downstream signal obtained from the downstream converter is used as the blood pressure signal, and the pressure corresponding to that time is measured as the blood pressure. t-A blood pressure measuring device for measuring blood pressure comprising means for successively approximating the pressure reduction width by decreasing the pressure reduction width each time it is repeated. (2) a cuff for pressurizing the upper arm; a converter attached to the cuff that detects a signal that detects changes in blood pressure due to heartbeat as a pulse wave and a signal that has a certain time difference;
A transducer on the downstream side that detects signals on the downstream side of the blood vessel generated based on the movement of the blood vessel wall, and a transducer on the downstream side that detects signals on the downstream side of the blood vessel generated based on the movement of the blood vessel wall. The method of rapidly reducing the pressure was performed by increasing and decreasing the initial pressure of the cuff, and rapidly changing the cuff pressure based on a signal that detected changes in blood pressure due to heartbeat as a pulse wave and a signal that remained for a certain period of time. Sometimes, the downstream signal obtained from the downstream converter is used as the blood pressure signal, and the pressure corresponding to that time is measured as the blood pressure, and each time this operation is repeated, the width of the pressure reduction is decreased to make successive approximations. A blood pressure measuring device comprising a downstream transducer for detecting a signal on the downstream side of the blood vessel generated based on the movement of the blood wall at a constant frequency, and a filter for detecting the downstream signal obtained by the blood vessel. .