JPH04158833A - Electronic hemomanometer - Google Patents

Abstract

PURPOSE:To eliminate a possibility of causing a congestion of a measuring part otherwise done by an excessive pressure as well as reduction in measuring time by easing a pressure rising speed with the regulation of the driving of a pressure pump when the pressure rising speed is higher than a reference speed value at an initial stage of a cuff & bag pressurization. CONSTITUTION:At an initial stage of a cuff & bag pressurization, a voltage to be applied to a pressure pump 2 is detected and when the detection voltage is lower than a fixed voltage, a pressure rising speed of a pressure cuff & bag 1 is gentle, hence lower than a reference speed value C. Therefore, even if a pressurization is continue at this pressurizing speed, a maximum blood pressure value can be estimated at the initial stage of pressurization with a judgment that a cuff & bag pressurization is detectable. When the detection voltage is determined to be higher than a fixed voltage, a PWM signal of a PWM oscillator 9 is changed so that the cuff & bag pressure rising speed will be about a reference speed value to control the driving of the pressure pump 2. Thus, the cuff & bag pressurization is continued at the cuff & bag pressure rising speed to estimate the maximum blood pressure while the cuff & bag pressurizing point is detected. The pressurization of the pressure cuff & bag 1 is stopped at the cuff & bag pressurization stop point, and an appropriate artery ischemia is done corresponding to a person to be measured.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention is an electronic blood pressure monitor that estimates the systolic blood pressure in the initial stage of cuff pressurization, and uses the estimated systolic blood pressure value to monitor the patient's blood pressure. The present invention relates to electronic blood pressure control 1 for finding an ideal cuff pressurization stop point.

(b) Conventional technology General electronic blood pressure monitors pressurize the cuff to block blood flow in the artery.
Blood pressure is measured during the decompression process. In order to ischemize the artery, it is necessary to apply a pressure higher than the subject's systolic blood pressure to the cuff. In conventional electronic blood pressure monitors, the subject sets (selects) a target pressure value in advance and pressurizes the cuff to the target value. Therefore, if the pressurization target value arbitrarily set by the person being measured is extremely over or under the systolic blood pressure of the person being measured, accurate blood pressure measurement may not be possible or the pressure may be too high. There were disadvantages such as pain.

Therefore, in recent years, an electronic sphygmomanometer has been proposed that estimates the systolic blood pressure at the initial stage of cuff pressurization and detects the cuff pressurization stop point based on this estimated systolic blood pressure value. According to this electronic sphygmomanometer, a cuff pressure that slightly exceeds the systolic blood pressure of the subject can be set as the cuff pressurization stop point. Therefore, since excessive pressure is not applied to the person to be measured, the blood pressure measurement time can be shortened, and disadvantages such as blood congestion at the measurement site due to excessive pressure are also eliminated.

(c) Problems to be Solved by the Invention In the electronic blood pressure monitor that detects the cuff pressurization stop point based on the estimated systolic blood pressure value, which has been proposed in recent years, the pressurizing means (pressurizing pump) that pressurizes the cuff is , Pressure switch ON/O
Drive and stop are performed by FF, and there is no control when pressurizing.

Therefore, as shown in FIG. 8, the rate of pressure increase in the cuff may be extremely different depending on the arm thickness of patients A and B or the way the cuff is wrapped. In patient A, the cuff pressure rise rate is slow, so the blood pressure (systolic blood pressure) can be estimated during pressurization, and the cuff pressurization stop point can be detected. However, in patient B, the rate of increase in cuff pressure was too fast, so there were drawbacks such as, for example, the number of extracted pressure pulse waves, etc. was small, making it difficult to estimate blood pressure (detection of cuff pressurization stop point).

This invention solves the above-mentioned problems, controls the rate of increase in cuff pressure to an appropriate rate, constantly estimates blood pressure during cuff inflation, and stops cuff inflation at a cuff pressure value that corresponds to the measurement person. The purpose is to provide an electronic blood pressure monitor that can

(d) Means and operation for solving the problem In order to achieve this object, the invention as set forth in claim 1 (
The electronic blood pressure monitor of the first invention has the following configuration.

The electronic blood pressure needle includes a cuff, a pressurizing means for pressurizing the cuff, a depressurizing means for reducing the pressure inside the cuff, a pressure detecting means for detecting the fluid pressure inside the cuff, and a blood vessel information that is collected during the pressurization or depressurization process. An electronic blood pressure needle comprising a blood vessel information detecting means for detecting blood vessel information, and a blood pressure determining means for determining a systolic blood pressure and a diastolic blood pressure based on an output signal of the blood vessel information detecting means and an output signal of the pressure detecting means, A pressure increase rate detection means for detecting a cuff pressure increase rate at an initial stage of pressure increase, a determining means for determining whether or not the pressure increase rate obtained by the pressure increase rate detection means is faster than a reference speed value, and this discrimination. The present invention is characterized by comprising a control means for controlling the pressurizing means so that the pressure rising speed becomes approximately the reference value speed when the pressure rising speed is determined by the means to be faster than the reference speed value.

In the electronic blood pressure monitor having such a configuration, the rate of increase in cuff pressure is detected in the initial stage of cuff pressurization. On the other hand, a reference speed value, that is, a cuff pressure increase speed value for a certain period of time that allows obtaining blood vessel information (for example, maximum pulse wave amplitude value) necessary for estimating systolic blood pressure is set in advance. Therefore, the detected cuff pressure increase rate is compared with the reference rate value. If the rate of increase in cuff pressure is smaller than the reference rate (the rate of increase is slow), the pressurization is continued without controlling the pressurization means, and the pressure point is slightly higher than the estimated systolic pressure. Stop cuff pressure at (cuff pressure stop point). On the other hand, if the cuff pressure increase speed is higher than the reference speed value (the increase speed is 22nd speed), it is determined that the vascular sensitivity necessary for estimating the systolic blood pressure cannot be obtained, and the driving of the pressurizing means is controlled. In other words, the pressurizing means is controlled so that the cuff pressure increase rate is approximately equal to the standard rate of implantation. This does not eliminate disadvantages such as not being able to obtain an estimated systolic blood pressure during cuff inflation and making it impossible to detect the cuff inflation stop point, but also ensures that the cuff is always applied appropriately depending on the person performing the measurement. A pressure stopping point can be obtained, which not only shortens the measurement time but also eliminates the pain caused by excessive pressure.

Further, the electronic blood pressure monitor according to the invention (second invention) described in claim 2 has the following configuration.

The electronic blood pressure monitor consists of a pressurizing means for pressurizing the cuff, a depressurizing means for reducing the pressure inside the cuff, a pressure detecting means for detecting the fluid pressure inside the cuff, and a pressure detecting means for collecting blood vessel information during the pressurization or depressurization process. An electronic sphygmomanometer comprising a blood vessel information detecting means for detecting blood vessel information, and a blood pressure determining means for determining a systolic blood pressure and a diastolic blood pressure based on an output signal of the blood vessel information detecting means and an output signal of the pressure detecting means, a pressure increase rate detection means for detecting a cuff pressure increase rate at an initial stage of pressure; a voltage detection means for detecting a power supply voltage for the pressurization means;
The present invention is characterized by comprising a fuzzy inference unit that executes fuzzy inference using the cuff pressure increase rate and voltage as input, and a control unit that controls driving of the pressurizing unit in accordance with the inference result of the fuzzy inference unit.

In the electronic sphygmomanometer having such a configuration, in the initial stage of cuff pressurization, the pressure rise speed detection means detects the pressure rise speed of the cuff, and the voltage detection means detects the voltage applied to the pressurization means. Then, these cuff pressure increase rates and the voltage to the pressurizing means are input to the fuzzy inference means. The fuzzy inference means executes fuzzy inference based on a predetermined rule based on the input pressure rise rate and voltage, and as a result of the inference, a PWM oscillator that drives the pressurization means, for example, a pressure pump, Outputs the DUTY of the pulse given to Thereby, the pressurizing means is controlled to a rate of increase in cuff pressure that allows an estimated systolic blood pressure value to be obtained during cuff pressurization.

(e) Embodiment FIG. 2 is a block diagram showing a specific embodiment of the air system and measurement circuit of the electronic blood pressure needle according to the invention set forth in claim 1.

A pressure pump 2, a pressure sensor 3, a high speed exhaust valve 4, and a slow exhaust valve 5 are connected to the cafe via a tube la. As the pressure sensor 3, for example, a diaphragm transducer using a strain gauge or a semiconductor pressure transducer element is used. The pressurizing pump 2 and the rapid exhaust valve 4 are controlled by a CPU (central processing unit) 8, which will be described later. Output signal of pressure sensor 3 (analog M
) is amplified by an amplifier 6 and converted into a digital value by an A/D converter 7. The CPU 8 takes in the output signal of the pressure sensor 3 converted into a digital value at regular intervals. Further, the pressurizing pump 2 has a PW electrically connected to the CPU 8.
It is connected to the M oscillator 9.

This pressurizing pump 2 is controlled by a PWM signal from a PWM oscillator 9 that receives commands from the CPU 8, and is controlled in an analog manner by changing the pulse DUTY.

Furthermore, the battery 12 is used for each component that requires a power source.
It is connected so that voltage is applied directly, and the above A/
Connected to D converter 7, voltage of battery 12 (analog quantity)
is converted into a digital signal by the A/D converter 7, and the CP
Incorporated into U8. The CPU 8 has a function of calculating a pulse wave amplitude value and a function of determining a diastolic blood pressure value and a systolic blood pressure value from the obtained pulse wave amplitude value and cuff pressure value. Also, CPU
8 has a function of estimating the extracted cuff pressure and systolic blood pressure at the time of maximum pulse wave generation based on the pulse wave information obtained during the initial pressurization stage of the cuff, and storing this in the memory. Further, the CPU 8 has a function of detecting the rate of increase in cuff pressure at the initial stage of cuff pressurization, and a function of determining whether the voltage of the battery 12 is higher than a certain voltage. Also, C.P.
U8 indicates that the cuff pressure increase rate is the reference rate value (cuff pressure increase rate at which the systolic blood pressure can be estimated during cuff inflation).
Determine whether it is faster than 30 mIIll (g/s),
If the cuff pressure rise rate is faster than the reference speed value, PWM
It has a function of controlling the drive of the pressurizing pump 2 via the oscillator 9. In addition, the CPU 8 has a start switch 11.
and a display 10 for displaying blood pressure values are electrically connected.

FIG. 1 is a flowchart showing specific processing operations of the electronic blood pressure monitor according to the embodiment.

When the start switch 11 of the blood pressure monitor is turned on, the pressurizing pump 2 is driven to start pressurizing the cafe [Step (hereinafter referred to as rST) 1]. Café pressurization starts, and in the initial stage of cuff pressurization, the cuff pressure and the pulse wave amplitude value on the cuff pressure are detected.

At the same time, the battery voltage is detected in the initial stage of cuff pressurization (Sr2). That is, the voltage applied to the pressure pump 2 is detected. At Sr1, it is determined whether the voltage detected at Sr2 is higher than a certain voltage. As shown in FIG. 4, if the detected voltage is lower than the constant voltage, the pressure rise speed of the cafe is slow and slower than the reference speed value (standard pressure rise speed, for example, 30 wHg/s) C. Therefore,
In the case of patient A and patient B, the pressure increase rate is less than or equal to the reference rate value C. Therefore, even if pressurization is continued at this pressurization rate, it is determined that the systolic blood pressure value can be estimated at the initial stage of pressurization and the cuff pressurization stop point can be detected. In this case, the determination in Sr1 is NO and the process proceeds to Sr7. on the other hand,
If Sr1 determines that the detection electrician is higher than a certain voltage, the determination of Sr1 becomes YES, and a feature quantity is extracted from the initial pressurization of the cuff (Sr1), that is, the rate of pressure rise of the cuff 1 is detected. . In Sr1, it is determined whether the pressure rise speed of the cafe is faster than the reference speed value. As shown in Figure 3, when the detected voltage is higher than the constant voltage,
The rate of increase in cuff pressure of patient B is faster than the reference rate value C in the initial stage of cuff pressurization.

Furthermore, in the case of patient A, the pressure rise rate is slower than the reference rate value C even under a similar high voltage. Therefore, there is no need to control the drive of the pressurizing pump 2 when it is applied to a patient. In other words, in the case of a patient, the determination in Sr1 is NO and the process proceeds to Sr7. However, in the case of patient B, the systolic blood pressure cannot be estimated (the cuff pressure stop point cannot be detected) at this cuff pressure increase rate. Therefore, in the case of patient B, the determination of Sr1 is YES, and the drive of the pressurizing pump 2 is controlled (S7
6). In other words, as shown in FIG. 5, by changing the PWM signal (pulse DUTY) of the PWM oscillator 9 so that the rate of increase in cuff pressure B' of patient B becomes the standard speed implantation, the pressure pump 2 Limit drive. Then, continue cuff inflation at a rate of increase of 20 cuff pressure (5T7), estimate the blood pressure (systolic blood pressure), and detect the cuff inflation stop point (5T7).
Sr1).

The cuff pressurization is stopped at the cuff pressurization stop point, and appropriate pressurization (arterial ischemia) is performed depending on the person being measured.

FIG. 6(A), FIG. 6(B), FIG. 6(C), and FIG. 7 are explanatory diagrams showing a specific embodiment of the electronic blood pressure monitor according to claim 2. .

The circuit configuration of this electronic sphygmomanometer is substantially the same as that of FIG. 2 described in the invention (embodiment) of claim 1, and therefore the description of the circuit configuration will be omitted. The feature of this electronic blood pressure monitor is that the CPU 8 has a fuzzy inference function. In other words, it is equipped with a fuzzy inference means that executes fuzzy inference by inputting the battery voltage (pump voltage) Vp and the initial pressurization speed P of the cafe, and according to the inference result of the fuzzy inference means, the pressurization means (pressure pump 2 and The present invention also includes a control means for controlling the driving of the PWM oscillator 9).

The following fuzzy rules are stored in the fuzzy rule memory.

■if Pr=VB, and Vp=Bthen
(If so) DUTY=Vs (60%)■if
Pr=B, andVp=Bthen
DUTY=s (70%)■i r
Pr=M, and Vp=Bthen
D U T Y -m (80%)■if
Pr=S, andVp=Bthen
DUTY=b (90%) ■if
Pr=VS and Vp=Bthen
DUTY=V b (100%) ■if
Pr-VB andVp=Mthen
D U T Y = m■i f Pr
=B and Vp=Mthen
DUTY= b s ■ i f Pr=M
and Vp=Mthen DUTY
=Vb■t f Pr=S and Vp
=Mthen DUTY=Vb@)i
r Pr−VS and Vp=Mt
hen DUTY-Vb■i
f Pr=VB and Vp=S
then DUTY=Vb@i
f Pr=B and Vp
=Sthen DUTY-Vb
■if P r=M and
Vp=Then DUTY=
Vboi f Pr=S and
Vp=Sthen DUTY
-Vbff Pr=VS andVp=
Then DUTY=Vb This rule is shown in a table in FIG. In this table, the horizontal axis represents the pump voltage, the vertical axis represents the initial inflation rate of the cuff, and the intersecting column represents the DUTY output of the pulse applied to the pressure pump 2, respectively.

Input of pump voltage Vp, initial pressurization speed Pr used in the above rules, and DUTY of pulse given to pressurization pump
Examples of membership functions for the output of are shown in Figure 6 (A) and Figure 6 (
B) and FIG. 6(C).

Figure 6 (A) is the input membership function of the pump voltage Vp, where "S" is extremely small when the voltage is 2V or less, and "m" is in the range of 2V to 5■, middle Furthermore, "b" means 5V or more, which means it is big. Moreover, FIG. 6(B) shows the initial pressurization speed Pr
For example, from O to 30 mmH
The range of about g/s is divided into 5 categories, 18 mmHg/s or less is extremely slow speed, r3., and the range from 8 mmHg/s to 22 mmHg/s is slightly slow speed. ．．
Normal speed “M” ranges from 20 mmHg/s to 24 mmHg/s, 22 mmHg/s to 26 mmHg/s
s range with slightly faster speed "B", and further 26tmrrH
This indicates that the range of g/s or higher is rVB, where the speed is extremely fast.

Furthermore, FIG. 6(C) shows the pulse D given to the pressure pump.
UTY output membership function from 60% to 100%
The range of is divided into 5 stages, "VS" is output 60%, output "S" is 70%, output "m" is 80%, output "b" is 9
The control values are set as 0% and the output "Vb" as 100%.

For example, if the battery 12 is exhausted, the voltage applied to the pressurizing pump 2 is 2 V or less, and the initial pressurization speed of the cafe is l 8 mm 11 g/s or less, the pump voltage Vp is r3. Then, the initial pressurization speed Pr becomes "VS", and the yaw 5 d U shown in the memory table of FIG.
T Y (7) The output is set to a control value of rVb (100%). On the other hand, if the battery 12 is new and has not been exhausted at all, the voltage applied to the pressure pump 2 is 5V or more, and the initial pressurization speed of the cafe is 26 mm 11 g/s or more, then the pump voltage Vp is rB, the initial pressurization rate Pr becomes rVBJ, and the output of DUTY is set to a control value of rVs (60%), as shown in the memory table of FIG. In other words, since the initial cuff inflation speed is too fast and the cuff pressure rises rapidly, the drive of the pressure pump 2 is restricted because it is impossible to estimate the blood pressure (systolic blood pressure) in the initial stage of cuff inflation at this speed. do. This slows down the cuff pressure increase rate and allows detection of an appropriate cuff pressurization stop point. In this way, by outputting the DUTY of the pulse given to the pump using fuzzy rules based on the battery voltage and initial inflation rate, the drive of the pressurization bomb 2 is controlled, and the systolic blood pressure is always estimated at the initial stage of cuff inflation. Control the rate of cuff pressure rise to a level that allows for.

(f) Effects of the invention As described above, the electronic blood pressure monitor according to claim 1 detects the rate of increase in cuff pressure at the initial stage of cuff pressurization,
If this rate of pressure increase is faster than the reference rate value, the drive of the pressurizing pump is restricted and the rate of pressure increase is slowed down, so that blood pressure can always be measured in the initial stage of cuff pressurization. Therefore, since the cuff pressure stop point can be reliably detected, the artery can be blocked with an appropriate cuff pressure depending on the person being measured, which not only shortens the measurement time but also prevents blood congestion at the measurement site due to excessive pressure. It can also eliminate widening.

Further, in the electronic blood pressure monitor described in claim 2, fuzzy inference is executed using the battery voltage and initial pressurization speed as input, and the drive of the pressurizing pump is controlled according to the result of this fuzzy inference. Therefore, the present invention has an excellent effect of achieving the object of the invention, such as being able to control the rate of increase in cuff pressure to such an extent that blood pressure can be estimated during the initial cuff pressurization stage.

[Brief explanation of the drawing]

FIG. 1 is a flow chart showing the processing operation of the electronic blood pressure monitor according to the embodiment described in claim 1, FIG. 2 is a circuit block diagram of the electronic blood pressure monitor according to the embodiment, and FIG. 3 is a flowchart showing the processing operation of the electronic blood pressure monitor according to the embodiment. FIG. 4 is an explanatory diagram showing a pressure curve in the initial stage of pressurization when the pump voltage of the meter is high. FIG. 5 is an explanatory diagram showing a pressure curve when blood pressure is measured by the electronic sphygmomanometer according to the embodiment, and FIGS. 6(A) to 6(C) are the electronic sphygmomanometer according to the embodiment according to claim 2. FIG. 6(A) is an explanatory diagram showing the membership function of the pump voltage, and FIG.
Figure (B) is an explanatory diagram showing the input membership function of the initial pressurization speed, and Figure 6 (C) is the DU of the pulse given to the pump.
An explanatory diagram showing the output membership function of TY, FIG. 7, is
FIG. 8 is an explanatory diagram showing a rule table in a memory, and FIG. 8 is an explanatory diagram showing a pressure curve during blood pressure measurement in a conventional electronic blood pressure monitor. 1: Cuff, 2: Pressure pump, 3: Pressure sensor, 8: CPU. 9: PWM oscillator, 12: battery. Patent applicant OMRON Co., Ltd. agent
Patent Attorney Shigeru Nakamura Nobuo No. 1 Figure 11h2 Figure 3 Figure 4 To (-11-----------・Rizday'fM→Δt ts5 Time→61!J(A) Figure 7 Figure 8

Claims (2)

[Claims] (1) A cuff, a pressurizing means for pressurizing the cuff, a depressurizing means for reducing the pressure inside the cuff, a pressure detecting means for detecting the fluid pressure inside the cuff, and detecting blood vessel information during the pressurizing or depressurizing process. In an electronic blood pressure monitor comprising a blood vessel information detection means and a blood pressure determination means for determining systolic blood pressure and diastolic blood pressure based on an output signal of the blood vessel information detection means and an output signal of the pressure detection means, an initial stage of cuff pressurization is provided. a pressure increase speed detection means for detecting the cuff pressure increase speed at the step; a comparison determination means for comparing and determining whether or not the cuff pressure increase speed detected by the pressure increase speed detection means is faster than a reference speed value; An electronic sphygmomanometer comprising: control means for controlling the pressurizing means so that the rate of increase in cuff pressure is equal to the reference rate when the means determines that the rate of increase in cuff pressure is faster than the reference rate value. (2) A cuff, a pressurizing means for pressurizing the cuff, a depressurizing means for reducing the pressure inside the cuff, a pressure detecting means for detecting the fluid pressure inside the cuff, and detecting blood vessel information during the pressurizing or depressurizing process. In an electronic blood pressure monitor comprising a blood vessel information detection means and a blood pressure determination means for determining systolic blood pressure and diastolic blood pressure based on an output signal of the blood vessel information detection means and an output signal of the pressure detection means, an initial stage of cuff pressurization is provided. a pressure increase rate detection means for detecting a cuff pressure increase rate; a voltage detection means for detecting a power supply voltage for the pressurizing means; a fuzzy inference means for executing fuzzy inference using the pressure increase rate and voltage as input; An electronic blood pressure monitor comprising: a control means for controlling driving of a pressurizing means according to the inference result of the inference means.