JPH0362087B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses a vibration method (oscillometric method) that extracts and calculates the arterial pulse wave component of each heartbeat superimposed on the cuff pressure to determine the peak and diastolic blood pressure periods. This relates to an electronic blood pressure monitor using the Tsuku method.

[Prior art] A typical electronic blood pressure monitor uses an electronic blood pressure monitor that uses an auscultation method (Rybarotchi-Korotkoff sound method) to determine blood pressure by detecting arterial blood flow sounds (Korotkoff sounds) using a microphone built into the cuff. A blood pressure monitor and an electronic blood pressure monitor (e.g.
Utility Model Publication No. 60-10601, Japanese Patent Application Publication No. 59-95033, etc.).

[Problems to be Solved by the Invention] FIG. 13 shows a blood pressure monitor using the auscultation method, in which a cuff 2' containing a rubber bladder 20 and a Korotkoff sound sensor 26 is wrapped around the upper arm 1, and the rubber bladder 2 is wrapped around the upper arm 1.
Air is supplied to the tube 21 connected to the tube 21 using a pressurizing means 3 formed of a pressurizing rubber bulb 22, etc., and the artery of the upper arm 1 is blood-isolated. Thereafter, the air in the rubber sac 20 is gradually evacuated and depressurized by the constant-speed exhaust function of the exhaust means 4, thereby transitioning from arterial ischemia to bleeding state, and the Korotkoff sound generated from the artery during the arterial compression operation is changed to Korotkoff sound. The sensor 26 detects the blood pressure, and the blood pressure monitor main body 30 determines the maximum and diastolic blood pressure based on the appearance and disappearance of Korotkoff sounds, and displays the display means 1.
The highest and lowest blood pressure values are displayed at 6. In the figure, 17 is an operation switch.

However, since the electronic blood pressure monitor using the auscultation method described above has the Korotkoff sound sensor 26 inside the cuff 2', it feels strange when the cuff 2' is attached to the upper arm 1 and pressure is increased or decreased, and it is difficult to measure blood pressure accurately. In order to do this, the Korotkoff sound sensor 26 had to be placed precisely at the artery position, and there was a problem in that it was troublesome to attach the cuff 2'. Furthermore, since the Korotkoff sound sensor 26 also detects noise emitted from the upper arm 1 and the cuff 2', there is a problem in that malfunctions are likely to occur.

Therefore, in order to solve such problems,
An electronic sphygmomanometer using a vibration method has been proposed, which extracts and calculates arterial pulse wave components to determine blood pressure. Pressure information separation means is formed to separate the pressure and the arterial pulse wave superimposed on the cuff pressure using filter means (low-pass filter, band-pass filter, etc.) consisting of an analog signal processing circuit. The pressure information separated by the pressure information separation means is digitized by the A/D converter, and the CPU
The digital calculation means configured using the above performs noise removal and comparison calculation for blood pressure determination to determine the maximum and diastolic blood pressures, and the determined maximum and diastolic blood pressures are displayed on the display means, and the pressure is Since the information separation means was constructed from an analog signal processing circuit, and the filter means constituting the pressure information separation means was formed from so-called hardware, the circuit configuration became complex, and the overall shape could not be miniaturized, making it difficult to carry. There were problems in that it was difficult to do so, and it was not possible to lower the price. Furthermore, in the above configuration example, it is not known whether the blood pressure measurement operation is being performed normally from the start of pressurization until the systolic blood pressure is displayed, which creates a sense of anxiety for the person being measured. It was hot.

The present invention has been made in view of the above points, and its purpose is to provide a cuff that can be easily attached without causing discomfort, has a simple structure, and can be easily miniaturized and reduced in price. Until the maximum value of the arterial pulse wave value is obtained and the systolic blood pressure value is calculated and displayed, the display means can notify the measurement operation status, giving the subject a sense of security. Our goal is to provide blood pressure monitors.

[Means for Solving the Problems] The electronic sphygmomanometer of the present invention includes a cuff that is attached to the main part of a person to be measured, a pressurizing means that increases the pressure inside the cuff, and a cuff that gradually increases the pressure inside the cuff. a pressure sensor that converts the pressure within the cuff into an electrical signal, an A/D converter that samples the pressure sensor output and converts it into a digital value;
Arterial pulse wave extraction means for digitally extracting an arterial pulse wave value from the pressure value output from the A/D converter during the gradual evacuation period, and digitally extracting a cuff pressure value from which the arterial pulse wave is removed from the pressure value. Pressure information separation means equipped with cuff pressure extraction means;
Storage means for storing arterial pulse wave values and cuff pressure values corresponding to the pulse waves extracted by the pressure information separation means; and systolic and diastolic blood pressure values by appropriately reading and comparing the values stored in the storage means. An electronic sphygmomanometer comprising a blood pressure determination means for determining a blood pressure value and a display means for displaying both determined blood pressure values, using a display having independent display areas for displaying a systolic blood pressure value and a diastolic blood pressure value. A blood pressure display means is formed, and the current cuff pressure value is displayed in the display area of the diastolic blood pressure value from the start of pressurization until the maximum value of the arterial pulse wave value is obtained.

(Function) The present invention is configured as described above, and since it does not use a cuff with a built-in microphone like an electronic blood pressure monitor for auscultation, the cuff can be easily worn without any discomfort, and it can also be used to detect arterial pulse waves. Since the value is extracted by digital calculation, the structure is simpler than the conventional vibration method which performs analog signal processing, and the structure can be easily reduced in size and cost. In addition, as a blood pressure display means, a display device having separate display areas for displaying the systolic blood pressure value and diastolic blood pressure value is used, and the diastolic blood pressure value is displayed from the start of pressurization until the maximum value of the arterial pulse wave value is obtained. Since the current cuff pressure value is displayed in the area, the measurement operation status can be notified by the display means until the maximum value of the arterial pulse wave value is obtained and the systolic blood pressure value is calculated and displayed. This makes it possible to give a sense of security to the person being measured.

(Embodiment) Figs. 1 to 4 show the basic configuration of an embodiment of the present invention. In Figs. , a rubber bladder 20 is built in, and a pressure means 3 consisting of a rubber bulb 22 is connected to this rubber bladder 20 via a tube 21, so that pressure can be applied until blood ischemia is achieved by pressing the rubber bulb 22. There is. The pressure inside the cuff 2 pressurized in this manner is gradually exhausted by the exhaust means 4 having an exhaust valve, and blood pressure is measured by the blood pressure monitor main body 30 during this gradual exhaustion period. A blood pressure monitor main body 30 to which one end is connected to the rubber bladder 20 and the other end of the tube 21 is connected includes a pressure sensor 5 that converts the pressure within the cuff 2 into an electrical signal as shown in FIGS. 2 and 3; A low-pass filter 6 that removes noise contained in the output of the pressure sensor 5, and an A/D converter that samples the noise-removed output of the pressure sensor 5 at a predetermined period (a period sufficiently shorter than the pulse wave) and converts it into a digital value. 7, and A/D converter 7 gradually during the exhaust period.
Arterial pulse wave extraction means 8a extracts an arterial pulse wave value V by digital calculation from the pressure value (digital value) output from the pressure value, and cuff pressure extracts by digital calculation the cuff pressure value P obtained by removing the arterial pulse wave from the pressure value. Pressure information separation means 9 equipped with extraction means 8b; storage means 10 for storing arterial pulse wave values V and cuff pressure values P corresponding to the pulse waves extracted by pressure information separation means 9; a blood pressure determining means 13 comprising a calculating means 11 for appropriately reading out the calculated values and performing comparison calculations; and a blood pressure determining means 12 for determining maximum and diastolic blood pressure values from the calculation results calculated by the calculating means 11; Maximum and diastolic blood pressure values determined in 13, exhaust speed, pulse monitor 1
4, and a display means 16 for appropriately displaying the cuff pressure output from the cuff pressure monitor 15, and an operation switch section 17 for controlling the blood pressure measurement operation, and the display means. 16 is arranged on the front side of the blood pressure monitor main body 30. Here, pressure information separation means 9, storage means 1
0, the calculation means 11, the blood pressure determination means 13, and both monitors 14 and 15 are formed by a microcomputer 18 using a CPU, ROM, RAM, and the like. In addition, as a means for pressurizing and exhausting the cuff 2,
As shown by imaginary lines in the figure, cuff pressure control means 19 may be provided to automatically control the pressurizing pump and the electromagnetic exhaust valve according to a predetermined program set in the microcomputer 18.

The basic configuration and operation described above will be explained in detail below. First, the basic configuration and operation for measuring systolic and diastolic blood pressure using the vibration method are as follows. Now, cuff 2 is placed on the upper arm 1 of the subject.
By attaching the cuff 2 and appropriately pressurizing and depressurizing it with the pressurizing means 3 and exhausting means 4, arterial ischemia is achieved, and arterial counter pressure at the time of opening is taken into the cuff 2, and air is conducted through the tube 21. The pressure is transmitted to the pressure sensor 5 and electrically converted together with the static pressure (cuff pressure) to obtain a pressure signal consisting of an analog signal. Next, this pressure signal is filtered to the extent that it can be removed by a low-pass filter 6, and then the pressure value converted into a digital value by an A/D converter 7 is sent to a microcomputer 18. Next, in the microcomputer 18, this A/D converter 7
The arterial pulse wave, which is observed as a phenomenon of arterial counterpressure, is separated, extracted, memorized, and calculated from the pressure value output from the system, and the systolic and diastolic blood pressure periods are determined, and at the same time, the maximum and minimum cuff pressures separated and extracted are calculated. The values corresponding to the blood pressure periods are read and displayed on the display means 16 as the maximum and diastolic blood pressure values.

The cuff 2 shown in FIG.
As experienced, the shape specified by JIS is adopted, keeping in mind that blood pressure values vary depending on the external shape of the cuff 2, especially the width. Note that blood pressure measurement in areas other than the upper arm 1, such as the forearm, wrist, chest,
The location may be selected as appropriate, such as on the thigh or lower leg. Furthermore, the cuff may be wrapped around the tail of an animal other than the human body, such as a rabbit or a mouse. The internal structure of these cuffs 2 needs to be thinner, have higher compliance, and increase responsiveness in order to better detect arterial counterpressure, so the inner fabric 23 of the cuff 2 is lightweight and elastic. Rubber bag 2
It is designed to withstand repeated pressurization of 0 to 300 mmHg or more, and to be as thin as possible. Furthermore, it is obvious that the best way to eliminate the influence of the inner fabric 23 is to eliminate the inner fabric 23 and apply the rubber bladder 20 directly to the body surface.
In this case, since the inner cloth 23 is not required, the structure is simplified. However, as another function of cuff 2, the detected arterial counterpressure is transferred to tube 2 through air conduction.
1, but in order to convey the level of arterial counterpressure without attenuation, in this example, the winding diameter,
A method is adopted in which the air portion 25 of the rubber bag 20 has a constant volume regardless of the deformation of the pressurized area during pressurization or the pressurizing pressure, and the outer fabric 24 of the cuff 2 is inflated with low compliance. The configuration is such that it does not allow this. Note that although the winding diameter may vary significantly depending on the human body part, this can be easily accommodated by preparing several types of cuffs 2 with different winding diameters.

In addition, the resonance frequency of the acoustic system closed by the tube 21 that transmits pressure from the cuff 2 to the pressure sensor 5 and the pressure control device is set to be sufficiently higher than the frequency of the arterial pulse wave (2 to 10 Hz), and the component parts Even if the resonant frequency changes due to variations in the
In order to transmit the arterial counterpressure without attenuation, in this embodiment, the length of the tube 21 is reduced in order to reduce the capacity.
In addition to making the tube 21 approximately 50 cm thick, the hardness of the tube 21 made of rubber is increased to allow for expansion due to arterial counterpressure.
It is set so that there is no contraction. Furthermore, the pressure sensor 5 can be directly connected to the rubber bladder 2 without going through the tube.
It may be arranged near 0, or it may be arranged in consideration of the responsiveness and frequency characteristics of the diaphragm so that arterial counterpressure can be reliably detected.

In addition, a low-pass filter 6 placed before the A/D converter 7 adjusts the cut-off frequency.
It is set at about 10 to 20Hz, and cuts out noise generated from inside the human body, noise generated by the cuff 2, noise transmitted from the outside, etc., and only detects static pressure (cuff pressure) and arterial counterpressure. It is now allowed to pass.

In addition, the sampling interval of the A/D converter 7 is set to about 10 to 100 samples/second, which can resolve arterial counterpressure, and the conversion speed (sample hold time) is set to 1/2 to 3/4 of the sampling interval. ,
It is made as long as possible so that noise at a level that cannot be removed by the low-pass filter 6 can be smoothed.

Next, the operation of each means constituted by the microcomputer 18 is as follows. First, the pressure information extraction means 9 converts the arterial pulse wave component and cuff pressure component included in the pressure value, which is a digital value converted from A/D by the A/D converter 7, into an arterial pulse wave value V, respectively. It is separated and extracted as a cuff pressure value P. That is, FIG. 7 shows the A/D converter 7
This shows the pressure curve of the pressure value output from
Curve A is a cuff pressure curve during gradual evacuation, and curve B is an arterial pulse wave curve superimposed on curve A. In the electronic blood pressure monitor according to the present invention, the maximum, Diastolic blood pressure values are beginning to be determined. Here, in the arterial pulse wave extraction means 8a, the peak value or area value of the arterial pulse wave is calculated from the curve B by digital calculation to obtain the arterial pulse wave value V of one heartbeat. The extraction means 8b extracts the curve A obtained by removing the arterial pulse wave component from the pressure curve of FIG. It's getting old.

5 and 6 show the arterial pulse wave value V and cuff pressure value P based on the pressure values shown in the pressure curve of FIG.
2 is a flowchart illustrating an example of digital computation that allows easy separation of . That is, in Fig. 8, the pressure value P Base at the start point of pulse wave rise and its time (time from the start of sampling to the start point of pulse wave rise)
tBase is the pressure value P Peak at the pulse wave peak point and its time (from the start of sampling to the peak point Peak
The arterial pulse wave value V and the cuff pressure value P are obtained by reading tPeak (the time required for the measurement) and performing digital calculations using these four values. FIG. 9 is an explanatory diagram of the operation of the pressure information separation means 9, in which a shows a pressure curve, b shows an extracted arterial pulse wave value V, and c shows an extracted cuff pressure value P. There is.

The arterial pulse wave value V and cuff pressure value P extracted as described above are sequentially stored in the storage means 10,
The blood pressure determination means 13 reads out the values stored in the storage means 10 as appropriate, and the calculation means 11 performs comparison calculations.
The blood pressure determination means 12 determines the systolic blood pressure and diastolic blood pressure periods. Here, methods for determining the systolic blood pressure period and diastolic blood pressure period include a boundary value determination method in which the period is determined based on a boundary value obtained by multiplying the maximum value of the arterial pulse wave value V by a predetermined ratio; There is a variation parameter judgment method that determines the timing based on the variation parameters of the value V (difference between previous and previous data, ratio of previous and previous data, difference between provisional maximum value or provisional minimum value, etc.). The cuff pressure value P at the systolic blood pressure period or diastolic blood pressure period is displayed as the systolic blood pressure value or the diastolic blood pressure value by the display means 16.
It is now displayed in

10 and 11 show an embodiment of the display means 16 according to the present invention, in which separate display areas 16 for systolic blood pressure values and diastolic blood pressure values are shown.
The display means 16 using a display having a and 16b.
and the maximum value of the arterial pulse wave value V from the start of pressurization.
The current cuff pressure value P is sequentially updated and displayed in the display area 16b for the diastolic blood pressure value until Vmax is obtained. In this embodiment, when a pulse wave component is extracted, a separately provided buzzer or a special segment 16c (or buzzer) in the display segment of the display unit is used to notify the arterial pulse wave value V. Nothing is displayed in the display area 16a for the systolic blood pressure value until the maximum value Vmax is obtained. Note that Fig. 10a shows the non-display state, and Fig. 10b shows the maximum value of the arterial pulse wave value V.
The current cuff pressure value P is displayed in the display area 16b for displaying diastolic blood pressure, and nothing is displayed in the display area 16a for displaying systolic blood pressure, before Vmax is obtained.

Now, as shown in FIG. 10a, the display means 16 is formed of a multi-digit numerical display made of a liquid crystal display element, and has display areas 16a and 16b for displaying the systolic blood pressure value and diastolic blood pressure value. is formed of three numerical parts (three-digit display) each having seven segments, and the maximum and diastolic blood pressure values determined by the blood pressure determining means 13 are digitally displayed. FIG. 11 is a flowchart showing the display operation. First, after the cuff 2 has been pressurized to an appropriate pressure, it is checked whether the cuff 2 is gradually being evacuated, that is, whether the pressure is being decompressed. It is checked whether or not there is an arterial pulse wave component in the pressure value output from the D converter 7, and if there is an arterial pulse wave component during depressurization, the pulse wave detection display segment 16c of the display (or buzzer) is activated.
This displays that the arterial pulse wave component has been detected, allowing the person to be measured to recognize that normal blood pressure measurement is being performed. Next, this arterial pulse wave component is extracted as the arterial pulse wave value V, the maximum value Vmax is determined, and the systolic blood pressure period is determined, and the cuff pressure value P at this systolic blood pressure period is used as the systolic blood pressure value. It is displayed in the display area 16a for display.
On the other hand, in the display area 16b for displaying the diastolic blood pressure, the arterial pulse wave value V
The current cuff pressure value P is sequentially updated and displayed until the maximum value Vmax is determined, that is, until the systolic blood pressure timing is determined and the systolic blood pressure value is determined,
It is designed to notify the person being measured that the pressure reduction operation is being performed normally. In addition, display means 1
In the display area 16a for displaying the systolic blood pressure No. 6, the maximum value Vmax of the arterial pulse wave value V is obtained, and nothing is displayed until the systolic blood pressure value is determined.

In this way, in the present invention, for systolic blood pressure value,
an independent display area 16a for the diastolic blood pressure value;
16b is used to form the display means 16, and the maximum value Vmax of the arterial pulse wave value V is displayed from the start of pressurization.
Display area 16 for systolic blood pressure value until
Since the current cuff pressure value P is sequentially updated and displayed in b, the status of the blood pressure measurement operation remains unchanged until the maximum value Vmax of the arterial pulse wave value V is obtained and the systolic blood pressure value is calculated and displayed. The display means 16 sequentially informs the subject of the measurement, thereby giving a sense of security to the person being measured. Furthermore, since the display of the display means 16 is effectively used to display the operating state, it is possible to realize a simple configuration and a small, low-cost electronic blood pressure monitor. In addition, in the embodiment, when a pulse wave component is extracted, a separately provided buzzer or a special segment among the display segments of the display unit is used to notify the arterial pulse wave value V
Since nothing is displayed in the display area 16a for the systolic blood pressure value until the maximum value Vmax is obtained, the blood pressure measurement operation can be displayed more clearly.

Embodiment 2 FIG. 12 shows another embodiment. In the embodiment 1, from the time when the maximum value Vmax of the arterial pulse wave value V is obtained until the diastolic blood pressure value is determined,
The display means 1 is configured to sequentially update and display the current cuff pressure value P in the display area 16b for the diastolic blood pressure value.
FIG. 6 is an explanatory diagram of the operation of the electronic blood pressure monitor having the configuration shown in FIG.

Now, the basic operations of the blood pressure determination operation and display operation of this embodiment are completely the same as those of the first embodiment, and the only difference is the display timing of the cuff pressure value P displayed in the display area 16a for displaying the diastolic blood pressure. .
That is, when the maximum value Vmax of the arterial pulse wave value V is obtained, that is, when the systolic blood pressure value is determined and displayed in the display area 16a for displaying systolic blood pressure, the display area 16b for displaying diastolic blood pressure is , the cuff pressure value P at that time is displayed, and thereafter, as shown in FIG. 12, the current cuff pressure value P is displayed in the display area 16b for displaying the diastolic blood pressure until the diastolic blood pressure value is determined.
The display is updated sequentially to indicate that the diastolic blood pressure measurement operation is being performed normally.

In this embodiment, the display area 16b for the diastolic blood pressure value is displayed after the maximum value Vmax of the arterial pulse wave value V is obtained until the diastolic blood pressure value is determined.
Since the display means 16 is formed so as to sequentially update and display the current cuff pressure value P, there is an effect that the subject can be informed that the diastolic blood pressure measurement operation is normal.

[Effects of the Invention] As described above, the present invention includes a cuff that is attached to the main part of a person to be measured, a pressurizing means that increases the pressure inside the cuff, and an exhaust system that gradually lowers the pressure inside the cuff. a pressure sensor that converts the pressure within the cuff into an electrical signal; and an A/D converter that samples the pressure sensor output and converts it into a digital value;
Arterial pulse wave extraction means for digitally extracting an arterial pulse wave value from the pressure value output from the A/D converter during the gradual evacuation period, and digitally extracting a cuff pressure value from which the arterial pulse wave is removed from the pressure value. Pressure information separation means equipped with cuff pressure extraction means;
storage means for storing arterial pulse wave values and cuff pressure values corresponding to the pulse waves extracted by the pressure information separation means;
It is composed of a blood pressure determining means that reads out the pressure values stored in the storage means as appropriate and performs a comparative calculation to determine the maximum and diastolic blood pressure values, and a display means that displays both determined blood pressure values. Since it does not use a cuff with a built-in microphone like the conventional method, the cuff can be easily put on without feeling uncomfortable, and the circuit configuration is simpler than the conventional method using the vibration method, which uses analog signal processing. In addition to this, it also has the effect of being easily miniaturized and lowered in price. In addition, the display means is formed using a display device having separate display areas for the systolic blood pressure value and the diastolic blood pressure value. Since the current cuff pressure value is sequentially updated and displayed in the display area, the status of the blood pressure measurement operation is displayed on the display until the maximum value of the arterial pulse wave value is obtained and the systolic blood pressure value is calculated and displayed. This has the effect of giving a sense of security to the person under test by sequentially informing the person being measured.Moreover, since the display device of the display means is used effectively to display this operating status, it can be realized with a simple configuration. This has the effect of providing a small, low-cost electronic blood pressure monitor.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG.
The figure is a block circuit diagram of the main part of the same as above, FIG. 3 is a block circuit diagram of the main part of same as above, FIG. 4 is a sectional view of main part of same as above, FIGS. 13 is an explanatory diagram of the operation of another embodiment, and FIG. 13 is a schematic configuration diagram of a conventional example. 1 is an upper arm, 2 is a cuff, 3 is a pressurization means, 4 is a pressure reduction means, 5 is a pressure sensor, 7 is an A/D converter, 8a is an arterial pulse wave extraction means, 8b is a cuff pressure extraction means, 9 is pressure information separation means; 10 is storage means;
13 is a blood pressure determination means, 16 is a display means, 16a,
16b is a display area.

Claims (1)

[Claims] 1. A cuff that is attached to the main part of a person to be measured to prevent blood flow;
A pressurizing means that increases the pressure inside the cuff, an exhaust means that gradually lowers the pressure inside the cuff, a pressure sensor that converts the pressure inside the cuff into an electrical signal, and a pressure sensor that samples the pressure sensor output and converts it into a digital value. an A/D converter that gradually extracts an arterial pulse wave value from the pressure value output from the A/D converter during the evacuation period by digital calculation, and a cuff pressure from which the arterial pulse wave is removed from the pressure value. Pressure information separation means equipped with cuff pressure extraction means for extracting values by digital calculation; storage means for storing arterial pulse wave values and cuff pressure values corresponding to the pulse waves extracted by the pressure information separation means; An electronic sphygmomanometer comprising a blood pressure determining means for determining the maximum and diastolic blood pressure values by appropriately reading and comparing values stored in the means, and a display means for displaying both determined blood pressure values. The blood pressure display means is formed by using a display device having separate display areas for displaying and diastolic blood pressure values, and the display area of the diastolic blood pressure value displays the current value from the start of pressurization until the maximum value of the arterial pulse wave value is obtained. An electronic blood pressure monitor characterized by displaying cuff pressure values. 2. The display means is configured to display the current cuff pressure value in the display area for the diastolic blood pressure value from when the maximum value of the arterial pulse wave value is obtained until the diastolic blood pressure value is determined. Claim 1
Electronic sphygmomanometer described in section.