JP2015154878A - Sphygmomanometry device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems that: a doctor and nurse are forced to use a specific type device since even if k sound is extracted with an electrocardiogram trigger method so that measurement may be carried out even during exercise or hard working, there is a poor noise reduction means, thus there is a case where incorrect blood pressure value is obtained, resulting in that ECG lag of electrocardiograph is unknown; and, even if non specific electrocardiograph may be used, since it is unknown that measurement is carried out correctly, the doctor and nurse carry out the blood pressure measurement while confirming the relevance of the blood pressure value at that field by themselves, resulting in time consumption in measurement.

SOLUTION: There is provided a sphygmomanometry device having a cardiograph synchronizing function in which vibration generated in blood vessel is extracted by an electrocardiogram trigger method with cardiographic signal. Automatic learning function is provided to a parameter required upon extraction of the vibration. The required parameter is ECG lag specific to an electrocardiograph. ECG lag measurement means is provided to the automatic learning function.

COPYRIGHT: (C)2015,JPO&INPIT

Description

   The present invention relates to a blood pressure measurement device, and more particularly to means for extracting information related to blood pressure values.

   Conventionally, methods for measuring blood pressure have been well known, and there are two typical methods: an auscultation method (Ribarotch Korotkov method) and an oscillometric method.

   Auscultation is a process in which the cuff attached to the arm is pressurized to drive the artery, and then the cuff is gradually depressurized, and the blood vessel sound that is generated when blood flows intermittently according to the heartbeat ( Korotkoff sound (hereinafter referred to as K sound) is detected by a stethoscope or a microphone built into the cuff, and the blood pressure value is determined by confirming the generation and disappearance of the K sound. The cuff internal pressure at the start is the maximum blood pressure, and the cuff internal pressure when the K sound disappears is the minimum blood pressure.

   When blood pressure is measured in a hospital or the like, the auscultation method described above is a commonly used method, and it is performed by many doctors and nurses using a stethoscope. However, even experienced doctors and nurses will have many noise components that are not related to blood pressure if the subject does not measure in a resting state, making it difficult to perform highly accurate and stable measurements. .

On the other hand, in the oscillometric method, after the cuff is pressurized and the artery is driven, the cuff is gradually depressurized, and the cuff internal pressure fluctuation (pressure) reflecting the vibration of the blood vessel wall synchronized with the pulsation of the heart. In this method, the blood pressure value is determined by checking the occurrence and disappearance of the fluctuations. In general, the cuff internal pressure when the fluctuations suddenly increase is the maximum blood pressure, and the blood pressure value decreases rapidly. The cuff internal pressure at the time of becoming the minimum blood pressure.
This method is used in many electronic blood pressure monitors used at home, but mainly for healthy people. If the subject is not measured in a resting state, as with auscultation, it is highly accurate and stable. Difficult to measure.

   In the field of preventive medicine such as hypertension and the latest medical fields, as the population is aging, many studies have been conducted on elderly people. There is a demand for a system capable of measuring blood pressure regardless of the state of the subject, and the performance for blood pressure measurement is required to be highly accurate and stable. Moreover, even if the subject is a healthy person, monitoring how the heart rate and blood pressure change during exercise is very useful information in clinical research.

   Thus, for example, when a subject is exercising or has a lot of body motion, there are systems and blood pressure measurement devices that detect a biological signal such as an electrocardiogram signal and perform blood pressure measurement in synchronization with the biological signal (for example, patents). Reference 1). FIG. 4 shows an embodiment described in Patent Document 1. This device uses an electrocardiogram signal as a gate signal, reduces the influence of noise by detecting and analyzing vibrations including K sound during the gate time when K sound is expected to be generated, It enables blood pressure measurement in a noisy environment, which is difficult to measure by auscultation performed by hearing.

   However, in Patent Document 1, the noise having the same frequency as the frequency of the K sound and the K sound are not sufficiently separated from each other, and thus the high-precision and stable performance is not satisfied. For this reason, doctors and nurses are not able to rely on the device to measure blood pressure. For this reason, when actually measuring blood pressure during exercise, doctors and nurses should always visually observe the subject's condition and the blood pressure value displayed on the blood pressure measurement device during the measurement and empirically compare and evaluate it. Thus, blood pressure measurement is performed while doctors and nurses themselves confirm the validity of blood pressure values.

Here, Patent Document 2 and Patent Document 3 consider the separation of the noise and the K sound which are the problems.
Patent Document 2 is characterized in that a separate electrocardiograph function is not required and the vibration obtained from the pulse wave detection means built in the cuff is used as a gate signal. And the filtering is performed based on the data by regarding the data as body motion noise. FIG. 6 shows a flow diagram of the filtering function described in FIG.
Originally, body motion noise is not constant noise, and body motion noise changes dynamically even during blood pressure measurement, and if it is considered as fixed noise, vibration components generated from the original blood pressure are generated in the vicinity. If necessary, even necessary components may be mistaken for noise and removed.
Therefore, in this method, there is a high possibility that the vibration generated from the original blood pressure is also removed by filtering.

Patent Document 3 focuses on the fact that when an electrocardiograph is used, a time delay occurs in the R wave and the K sound, and this time follows and fluctuates with the cuff internal pressure, and a means for delaying the heartbeat by one beat is provided. It has the characteristic of trying to extract sound. The method is considered to be close to the present invention, but the preconditions are completely different. That is, Patent Document 3 is based on the premise that an ECG lag unique to an electrocardiograph is known, and does not take into account any delay time that may change in accordance with the performance improvement of each company's electrocardiograph.
Therefore, in Patent Document 3, when the required level of accuracy is required, an electrocardiograph manufacturer designation or an extremely time-consuming initial setting is required, which is very inconvenient, unlike the initial speculation. Become.

   Therefore, in the blood pressure measurement devices of Patent Documents 1 to 3, the original role of the automatic blood pressure monitor is not fully utilized.

JP-A-61-193644 JP 2001-008908 A JP-A-10-272109

   Even if K sounds are extracted using an electrocardiogram signal as a gate signal so that measurement is possible even during exercise or when body movement is intense, noise removal means are poor, and K sound and noise are not sufficiently separated during the gate time. Therefore, the device may erroneously recognize noise as a K sound and determine an incorrect blood pressure value. Also, since the ECG lag generated by the ECG manufacturer, model, ECG setting conditions, etc. is an unknown value, the ECG model is usually specified to obtain the correct gate signal. However, when an electrocardiograph other than the designated model is used, the ECG lag shows a different value for each model, so that it is impossible to normally determine a correct blood pressure value using the electrocardiogram trigger method. Therefore, the electrocardiograph used by doctors and nurses is restricted. Also, if you use an electrocardiograph other than the one you specify, even if it can be used rarely, it will be unclear whether it can be measured normally, so doctors and nurses leave all blood pressure measurement devices to blood pressure measurement. At all times during the measurement, the state of the subject and the blood pressure value displayed on the blood pressure measurement device are visually observed and compared empirically, and the appropriateness of the blood pressure value is confirmed on the spot by the doctor or nurse himself. The blood pressure is measured while checking, and the time during measurement is restricted.

The invention of claim 1 includes a cuff that is worn to compress a blood vessel of a subject;
A pressure control function for pressurizing or depressurizing the inside of the cuff by injecting or discharging air into the cuff;
A cuff internal pressure measuring function for measuring the pressure in the cuff;
A vibration A detection function for detecting vibration A generated from the blood vessel at the time of pressurization or decompression in the cuff;
A vibration B extraction function for removing noise from the vibration A and extracting the vibration B;
A vibration intensity deriving function for obtaining a vibration intensity of the vibration B;
An electrocardiogram signal detection function for detecting the electrocardiogram signal of the subject;
An electrocardiogram synchronization function for extracting the vibration A or the vibration B by an electrocardiogram trigger method using the electrocardiogram signal;
In the blood pressure measuring apparatus provided with
An automatic learning function is provided for a parameter required when extracting the vibration A or the vibration B, and the required parameter is an ECG lag specific to an electrocardiograph, and an ECG lag measuring means is provided for the automatic learning function. It is characterized by that.

The invention of claim 2 includes a cuff to be worn to compress the blood vessel of the subject;
A pressure control function for pressurizing or depressurizing the inside of the cuff by injecting or discharging air into the cuff;
A cuff internal pressure measuring function for measuring the pressure in the cuff;
A vibration A detection function for detecting vibration A generated from the blood vessel at the time of pressurization or decompression in the cuff;
A vibration B extraction function for removing noise from the vibration A and extracting the vibration B;
A vibration intensity deriving function for obtaining a vibration intensity of the vibration B;
An electrocardiogram signal detection function for detecting the electrocardiogram signal of the subject;
In the blood pressure measurement device provided with an electrocardiogram synchronization function for extracting the vibration A or the vibration B by an electrocardiogram trigger method using the electrocardiogram signal,
A function for automatically learning a parameter required when extracting the vibration A or the vibration B is provided, and the required parameter is a dedicated filter for extracting a K sound peculiar to a subject, and the automatic learning function A function of forming the dedicated filter using a frequency spectrum of K sound is provided.

The invention of claim 3 includes a cuff that is worn to compress the blood vessel of the subject;
A pressure control function for pressurizing or depressurizing the inside of the cuff by injecting or discharging air into the cuff;
A cuff internal pressure measuring function for measuring the pressure in the cuff;
A vibration A detection function for detecting vibration A generated from the blood vessel at the time of pressurization or decompression in the cuff;
A vibration B extraction function for removing noise from the vibration A and extracting the vibration B;
A vibration intensity deriving function for obtaining a vibration intensity of the vibration B;
An electrocardiogram signal detection function for detecting the electrocardiogram signal of the subject;
In the blood pressure measurement device provided with an electrocardiogram synchronization function for extracting the vibration A or the vibration B by an electrocardiogram trigger method using the electrocardiogram signal,
A feature of automatically learning a parameter required when extracting the vibration A or the vibration B is provided.

   According to the present invention, even if exercise or body movement is intense, no matter what electrocardiograph is used, highly accurate and stable blood pressure measurement is possible, There is no need to visually observe the state of the subject and the blood pressure value displayed on the blood pressure measurement device. Therefore, doctors and nurses can use electrocardiographs without any model restrictions. In addition, the time during blood pressure measurement, which has been restrained by doctors and nurses until now, can be used for other medical services and clinical research.

It is the flowchart of Example 1 which showed the learning function of the blood-pressure measuring device by this invention. It is the flowchart of Example 1 which showed the learning function of the blood-pressure measuring device by this invention. 1 is a block diagram schematically showing a configuration of a blood pressure measurement device according to the present invention. It is an Example described in Patent Document 1. 10 is an example of a display method described in Patent Document 3.

   Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

FIG. 1 is an example showing a learning function of a blood pressure measurement device according to claim 1 of the present invention, and is a flowchart thereof. FIG. 1A is a flowchart showing a series of flows of the CPU 37 of the main body when the ECG lag learning function is used, and FIG. 1B is a flowchart showing a series of flows of the ECG lag learning function itself. FIG. 1C is an explanatory diagram showing a state in which the position of the K sound and the position of the R wave are shifted when measuring the ECG lag.
FIG. 2 is a flowchart showing an embodiment of the learning function of the blood pressure measurement device according to claim 2 of the present invention.
FIG. 3 is a block diagram schematically showing the configuration of the blood pressure measurement device according to claims 1 to 3 of the present invention, and the flow of the operation of the blood pressure measurement device of the present invention will be described with reference to this figure.
4 and 5 are explanatory diagrams of the measuring apparatus described in Patent Document 1 and Patent Document 3 described in the previous stage.

First, a general outline of the overall structure of the main body 41 shown in FIG. 3 will be described.
In FIG. 3, 31 is a cuff, 32 is a microphone, 33 is a cable, 34 is a pressure sensor, 35 is a pressure control unit, 36 is a pump, 37 is a CPU, 38 is an electrocardiogram signal input unit, 39 is a display unit, and an operation panel , 40 is an external input / output, 41 is a main body, main body case, 42 is an electrocardiograph, 43 is an electrocardiographic sensor, and 45 is an external device.

   The cable 33 is a cable having both a hollow tube-like air circuit function and an electric wire function. The cuff 31 is connected to the pressurization pump 36, the pressure sensor 34, and the pressure control unit 35 of the main body 41 by a cable 33, and the pressurization pump 36, the pressure sensor 34, and the pressure control unit 35 are connected to the CPU 37 by an electric signal circuit. The microphone 32 is connected to the CPU 37 of the main body 41 by a cable 33. The pressure signal of the cuff internal pressure measured by the pressure sensor 34 and the signal of the vibration A including the K sound generated from the blood vessel detected by the microphone 32 are sent to the CPU 37 and processed, whereby the CPU 37 detects the cuff internal pressure. , K sound intensity, frequency spectrum, systolic blood pressure value, diastolic blood pressure value and the like are obtained. The CPU 37 is connected to the display unit 39 and displays each data on the display unit 39.

   The electrocardiogram sensor 43 is connected to the CPU 37 by connecting the electrocardiograph 42 to the electrocardiogram signal input unit 38 of the main body 41. The signal obtained from the electrocardiographic sensor 43 is used as data for extracting the K sound, and the obtained heart rate is displayed on the display unit 39 together with the data. The external device 45 is a memory expansion device or a monitor device in a separate room, and is connected to the CPU 37 through the external input / output 40 of the main body 41.

Next, the cuff 31 and the microphone 32 illustrated in FIG. 3 will be described.
The cuff 31 and the microphone 32 are connected to the main body 41 of the blood pressure measurement device by a cable 33. When the cuff 31 and the microphone 32 are used, they are united and wound around a portion for measuring the blood pressure of the subject. . In this case, it is highly convenient to provide a dedicated bag separately and insert the cuff 31 and the microphone 32 into the bag so as to be integrated together in advance.

   The material of the cuff 31 is made of a resin that expands or contracts, or a composite of resin and rubber, and the size of the cuff 31 is selected depending on a newborn, an infant, a child, an adult, an obese person, and the like. In addition, the standard of the size of the cuff 31 is publicly known and confirmed, and is confirmed by a report of JIS T 1115-2005-5.4, JIS T 4203-1976, WHO Expert Committee, or a report by WTO recommendation. Can do.

   The microphone 32 is a high-accuracy microphone such as an ECM (electret condenser microphone) or a MEMS microphone, or a high-accuracy vibration sensor applied such as a piezoelectric sensor or a strain sensor. When the cuff 31 is wound around the subject, K is generated from the blood vessel. The microphone 32 is arranged at a position where the vibration A including sound is easily detected.

   Actually, the cuff 31 is used so as to overlap the microphone 32, and the pressure of the cuff 31 is used to fix the microphone 32 on or near the blood vessel. If 32 is fixed to the determined arrangement of the cuff 31, it is convenient to attach and detach before and after use.

   In order to improve detection performance, a plurality of the high-precision microphones or high-precision vibration sensors used for the microphone 32 can be used and arranged at a plurality of locations. In addition, when performance is required rather than convenience during use, the microphone 32 is placed on the subject's blood vessel in advance and the cuff 31 is wound around the subject later, or after the cuff 31 is wound around the subject. There is a method of inserting the microphone 32 between the cuff 31 and the subject.

Next, the operation of the main body 41 shown in FIG. 3 will be described.
When the subject wears the cuff 31 and the microphone 32 and inputs a measurement start signal using the blood pressure measurement start button on the operation panel 39, the pump 36 operates to send air into the cuff 31 and pressurize it. The cuff internal pressure of the cuff 31 is controlled by the pressure control unit 35, and in a standard measurement at rest, the pressure control unit 35 is pressed by the CPU 37 after reaching a certain pressure value that is pressurized and drives the artery. By controlling the quick exhaust valve and the proportional control valve, the pressure is reduced and the measurement is completed. In the blood pressure measurement device of the present invention, the detection of the vibration A can be selected between the pressurization and the depressurization, and can be changed by switching at the initial setting.

   Actually, if the blood pressure is higher than expected, if the pressure is insufficient for arterial blood pumping, additional pressure is applied, or if the pressure changes excessively due to body movement, the pressure is reduced. To do. By repeating this process, the pressure controller 35 and the pump 36 are controlled and measured through the CPU 37 so that blood pressure can be stably measured.

   When exercising or body movement is intense, for example, when the cuff 31 is moved violently, the cuff 31 collides with the subject's clothes and surrounding objects and rubs. It will be detected as a signal.

   Therefore, in the blood pressure measurement device according to claim 1 of the present invention, an electrocardiographic signal is used when measurement is difficult due to a large amount of external noise.

In general, the electrocardiogram trigger method is to open the gate when it is delayed for a certain time with reference to the trigger (R wave) of the electrocardiogram (K sound lag: delay time from R wave to K sound), and then for a certain time zone (gate time) This is a method for extracting data.
The ECG lag refers to a delay time that indicates how much time delay occurs in the ECG waveform output as an electrical signal from the electrocardiograph from the actual ECG waveform.

   In FIG. 3, when an electrocardiograph 42 is connected to an electrocardiogram signal input unit 38 of the main body 41, an electrocardiographic sensor 43 is attached to the subject, and blood pressure measurement is started, an electrocardiogram trigger (R wave) detected from the electrocardiographic sensor 43 is started. ) Is sent to the CPU 37. By using the electrocardiogram trigger as a gate signal and determining the gate time including the generation time of the K sound predicted from the electrocardiogram trigger, the vibration A signal or the vibration B signal including the K sound generated within the gate time is determined. Therefore, it is possible to extract a vibration signal including a more accurate and stable K sound.

   Further, the obtained vibration signal is subjected to spectrum analysis using FFT analysis, so that a frequency spectrum can be derived, and signal extraction with higher accuracy becomes possible.

   When the electrocardiograph 42 is not provided, the heart rate signal detected from the heart rate sensor 44 can be used in place of the electrocardiogram signal by attaching the heart rate sensor 44 to the subject and connecting it to the main body 41.

   These measurement methods using an electrocardiogram trigger are very effective methods when there are many external noises and measurement is difficult, and further improve the performance of the highly accurate and stable blood pressure measurement described above.

   However, when the delay time is unknown, the electrocardiogram trigger method cannot be normally used.

   Therefore, in the blood pressure measurement device according to claim 1 of the present invention, the delay time with the electrocardiogram signal is automatically learned so that any difference between the electrocardiograph manufacturers and any individual difference of the electrocardiographs can be dealt with. The function to do was provided.

The function will be described below.
In FIG. 1A, if the ECG lag is known, when the measurement is started (S11), the blood pressure calculation is performed by shifting the ECG waveform by the time corresponding to the known ECG lag (S14). Is determined (S15, S35). The blood pressure calculation is a flowchart when it is assumed that there is no dedicated filter in the flowchart of FIG.

In general, after dealing with ECG manufacturers in advance, consulting in advance or confirming in advance, most ECG lags are dealt with by specifying an ECG with a known model. is there.
On the other hand, since ECG lag is an unnecessary parameter in electrocardiographic measurement if it is used without prior confirmation, etc., ECG lag is not disclosed or guaranteed by each ECG maker. Is an unknown number. The ECG trigger method cannot be used with unknown values.
In such a case, it seems that it can be dealt with by actually measuring and acquiring the ECG lag of the electrocardiograph to be used, but since this is a very difficult task, it is actually measured and acquired in view of its labor. There is no one other than us.

   Recently, there has been an improvement in the performance of electrocardiographs and there are also very excellent electrocardiographs. However, as described above, ECG lag is a characteristic that has nothing to do with electrocardiographs. There are some manufacturers who don't know what value the ECG lag of ECG released by will be.

   In order to solve these problems, the blood pressure measurement device according to claim 1 of the present invention observes the positional deviation between the R wave and the K sound and finds the optimum value of the positional deviation, thereby delaying the electrocardiogram signal delay time ( An ECG lag measuring means capable of determining ECG lag) was developed, and the measurement result was obtained by learning during blood pressure measurement work.

Since it is difficult to find the ECG lag measuring means by one measurement, it is necessary to carry out the steps of blood pressure measurement (S11 to S15) in FIG.
First, the ECG lag is compared and evaluated from the K sound (S21) obtained by blood pressure measurement and the R wave (S22) obtained from the ECG waveform, and the optimum value is narrowed down to several points (S23). The optimum value may be determined by shifting the actual position of the R wave after considering the K sound lag that varies depending on the subject, the cuff pressure, and the heart rate. The ECG waveform is further shifted from the optimum value to obtain several points having a high evaluation value (S23), and stored (S24).

This is shown in FIG. The upper figure in this figure is a figure before shifting the position of the R wave, and the lower figure is a figure when the position of the K sound is fixed and the position of the R wave is shifted.
Here, while shifting the position of the R wave, the overlap evaluation value of the position of the K sound and the R wave is calculated, and the position that becomes the optimum evaluation value is found. The overlap evaluation value is derived from an evaluation calculation formula from the difference between the position information of the K sound and the R wave.
However, when it is found by only one measurement, the reliability of the position is not high, and it is necessary to measure several times. Also, it is advisable to leave the top several evaluation values in one measurement so that they can be compared widely at that time.
If this process is repeated a plurality of times and finally narrowed down to one (S26), the learning is completed and the ECG lag specific to the electrocardiograph is determined (S28). After that, the ECG waveform is shifted by the determined lag using the determined ECG lag (S14), blood pressure calculation (S15) is performed, and the result is displayed on the display unit 39.

In the present invention, in order to enable more accurate evaluation, a process (heart rate change BAT evaluation means) that can be evaluated even after changing the heart rate is incorporated in the program. Actually, there is provided a resting evaluation means for evaluating at rest and a low load evaluating means for evaluating at low load (light exercise), and blood pressure measurement and ECG lag learning described above at rest and low load (light exercise). I do. The plurality of candidates acquired in S23 include a true ECG lag and a false ECG lag (true ECG lag ± multiple of RR interval), and the heart rate does not change (RR interval does not change). These candidates remain unchanged. However, the true ECG lag does not change when learning at low load, but because the heart rate (RR interval) changes, the false ECG lag is different from that at rest, and the true ECG lag is accurate. It becomes possible to learn well.
Note that the low-load evaluation means does not require any additional process and can be performed during normal exercise load measurement.

When evaluation was actually made using this means, it was found that the true value of the ECG lag was obtained by measuring blood pressure 2-6 times per person. Considering how to deal with ECG lags that have been unknown so far, the man-hours for obtaining ECG lags are drastically reduced, and the specification of the model of the electrocardiograph is no longer required, thereby freeing you from any restrictions.
Therefore, it can be understood from the above that the present invention is an epoch-making means and a function that has never existed.

If the flow of the learning function is extracted, it is as shown in FIG.
A K sound is detected from the blood pressure vibration (S21), and an R wave is detected from the ECG waveform (S22). The evaluation value of the delay time as ECG lag is calculated from the position of the K sound and the R wave, and several points with high evaluation values are acquired (S23) and written in the CPU 37 (S24). Thereafter, past delay time candidates are read out (S25), and whether or not learning is completed is determined based on whether or not candidates are narrowed down to one (S26, S27, S28).
The flow of the learning function shown in FIG. 1B corresponds to the ECG lag learning (S13) portion of FIG.
When learning is completed (S28), the learning loop (S13) is not entered again (S12). In addition, since the value varies depending on the manufacturer, model, and setting conditions of the electrocardiograph, when trying to make effective use of this function, every time there is any change, It is preferable to repeat such learning (S11 to 15).

   An example of a method for taking into account the K sound lag that varies depending on the subject described above is disclosed in Japanese Patent Application Laid-Open No. 07-265274. However, in the present invention, the automatic learning function described above or described later is provided also in the K sound lag, similarly to the ECG lag.

   As described above, by using the ECG lag obtained by the learning function according to claim 1, it becomes possible to extract a high-accuracy K sound from a vibration signal including noise, which is highly accurate and stable. Blood pressure measurement became possible. This eliminates the problem of ECG lag, which is an inherent problem for each electrocardiograph, and eliminates the need to visually observe the state of the subject and the blood pressure value displayed on the blood pressure measurement device at all times during the measurement. The time during blood pressure measurement that has been constrained by doctors and nurses can be used for other medical services and clinical research.

   In the blood pressure measurement device according to claim 2 of the present invention, the electrocardiogram trigger method is used in the same manner as described above, but in order to further improve the filtering function against noise, blood pressure measurement at the time of resting of the subject is performed in advance, and the data The CPU 37 learns the characteristic of the K sound peculiar to the subject obtained by analyzing the above, and has a function of performing blood pressure measurement during exercise or when body movement is intense. In addition, since the initial initial state is set to a standard value, there is no problem in the measurement even if the blood pressure measurement at rest is not actually performed, but the resting data is obtained in advance as much as possible. It is preferable to keep it. With this function, since the learning function is repeatedly operating during measurement, the blood pressure value obtained as the blood pressure is measured approaches a highly accurate and stable true value.

FIG. 2 shows a flowchart of the learning function. The operation of the device main body 41 will be described with reference to FIG.
The vibration A signal (S31) detected by the microphone 32 is processed by a first filter (bandpass analog filter), converted into a digital signal by an A / D converter, sent to the CPU 37, and then sent to a second filter ( In the FIR filter and the finite impulse response filter), a dedicated filter formed according to the frequency spectrum of the K sound obtained in the past measurement for the subject is read (S32), and the dedicated filter is formed for a certain time (S33). By processing, the signal of vibration B is extracted (S33). The K sound intensity is derived from the magnitude of the vibration B signal, and the frequency spectrum is derived by subjecting the vibration B signal to spectrum analysis (S34) using FFT (Fast Fourier Transform) analysis. Then, the blood pressure value is determined (S35). On the other hand, after that, the frequency spectrum is stored in the CPU 37 and formed again as a new dedicated filter (S36, S37).

   The pressure signal obtained by the pressure sensor 34 is sent to the CPU 37 through the first filter, and is then derived as the cuff internal pressure of the cuff 31 by the second filter (S32).

In the blood pressure measurement device according to the first aspect of the present invention, the delay time and the gate time in the above-described electrocardiogram trigger method can also be determined using the learning function (S13) according to the second aspect.
In such a case, the flowchart of FIG. 2 is included in the work relating to blood pressure calculation in the flowchart of FIG. That is, if the flow of FIG. 2 is included in the flow of FIGS. 1A and 1B, the blood pressure measurement device according to claim 3 is obtained.

   As described above, it is possible to extract the K sound with high accuracy from the vibration signal including noise by repeatedly processing the characteristic of the K sound obtained by the learning function according to claim 2. Highly accurate and stable blood pressure measurement became possible. This eliminates the need to visually observe the condition of the subject and the blood pressure value displayed on the blood pressure measurement device at all times during the measurement, so that the time during blood pressure measurement that has been restrained by doctors and nurses can be It can be used for medical services and clinical research.

   On the other hand, blood pressure can be measured for a long time by inputting measurement time settings from the operation panel 39 in advance and adding a function to automatically start and stop measurement. For example, the blood pressure measurement is performed at 1 minute intervals, and the measurement is repeated continuously for 60 minutes. By using this function in addition to highly accurate and stable measurement, doctors and nurses are not restrained by blood pressure measurement. It can be used for medical work and clinical research.

   Furthermore, by using the external input / output 40, an additional memory for storing data is added to the external device 45 so that the data stored in the CPU 37 does not become full, the screen of the main body 41 is displayed on a monitor in a separate room, Is output by a telemeter or the like, so that blood pressure measurement in a separate room can be managed.

   In measuring and diagnosing the biological data of a subject, a highly accurate and stable performance of the blood pressure value is essential. The blood pressure measurement device according to the present invention can provide various data with high reliability for the K sound to doctors and nurses, and is considered to be a device that contributes sufficiently to future medical development.

   In the above-described embodiment, the blood pressure measuring device using the auscultation method is mainly described. However, the same thing can be done with the blood pressure measuring device using the oscillometric method.

31 Cuff 32 Microphone 33 Cable 34 Pressure sensor 35 Pressure control unit 36 Pump 37 CPU
38 ECG signal input section 39 Display section, operation panel 40 External input / output 41 Main body, main body case 42 ECG meter 43 ECG sensor 44 Heart rate sensor 45 External equipment

Claims (3)

A cuff worn to compress the subject's blood vessels;
A pressure control function for pressurizing or depressurizing the inside of the cuff by injecting or discharging air into the cuff;
A cuff internal pressure measuring function for measuring the pressure in the cuff;
A vibration A detection function for detecting vibration A generated from the blood vessel at the time of pressurization or decompression in the cuff;
A vibration B extraction function for removing noise from the vibration A and extracting the vibration B;
A vibration intensity deriving function for obtaining a vibration intensity of the vibration B;
An electrocardiogram signal detection function for detecting the electrocardiogram signal of the subject;
An electrocardiogram synchronization function for extracting the vibration A or the vibration B by an electrocardiogram trigger method using the electrocardiogram signal;
In the blood pressure measuring apparatus provided with
An automatic learning function is provided for a parameter required when extracting the vibration A or the vibration B, and the required parameter is an ECG lag specific to an electrocardiograph, and an ECG lag measuring means is provided for the automatic learning function. A blood pressure measurement device characterized by that. A cuff worn to compress the subject's blood vessels;
A pressure control function for pressurizing or depressurizing the inside of the cuff by injecting or discharging air into the cuff;
A cuff internal pressure measuring function for measuring the pressure in the cuff;
A vibration A detection function for detecting vibration A generated from the blood vessel at the time of pressurization or decompression in the cuff;
A vibration B extraction function for removing noise from the vibration A and extracting the vibration B;
A vibration intensity deriving function for obtaining a vibration intensity of the vibration B;
An electrocardiogram signal detection function for detecting the electrocardiogram signal of the subject;
In the blood pressure measurement device provided with an electrocardiogram synchronization function for extracting the vibration A or the vibration B by an electrocardiogram trigger method using the electrocardiogram signal,
A function for automatically learning a parameter required when extracting the vibration A or the vibration B is provided, and the required parameter is a dedicated filter for extracting a K sound peculiar to a subject, and the automatic learning function A blood pressure measuring apparatus provided with a function of forming the dedicated filter using a frequency spectrum of K sound. A cuff worn to compress the subject's blood vessels;
A pressure control function for pressurizing or depressurizing the inside of the cuff by injecting or discharging air into the cuff;
A cuff internal pressure measuring function for measuring the pressure in the cuff;
A vibration A detection function for detecting vibration A generated from the blood vessel at the time of pressurization or decompression in the cuff;
A vibration B extraction function for removing noise from the vibration A and extracting the vibration B;
A vibration intensity deriving function for obtaining a vibration intensity of the vibration B;
An electrocardiogram signal detection function for detecting the electrocardiogram signal of the subject;
In the blood pressure measurement device provided with an electrocardiogram synchronization function for extracting the vibration A or the vibration B by an electrocardiogram trigger method using the electrocardiogram signal,
A blood pressure measuring apparatus having the features of claim 1 and claim 2, wherein a function for automatically learning a parameter required when extracting the vibration A or the vibration B is provided.

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