JPS59160437A - Cardiac pulse reference type electronic hemomanometer - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic blood pressure monitor, and more particularly to a heart rate reference electronic blood pressure monitor.

It is clear that blood pressure measurement is necessary for normal treatment, health management, etc. Moreover, the demands are high in emergency medical care. However, in emergency medical care, etc., when considering use in ambulances, the environment is extremely unsuitable for conventional blood pressure monitors due to vibrations, noise, etc., and there may be cases where the blood pressure monitor malfunctions and measurements cannot be taken. There were many. The common blood pressure measurement method is the Korotkoff sound detection method.
The Korotkoff sound that occurs and disappears during the process of depressurization of the cuff is detected, and the arm cuff pressure when it occurs and disappears is defined as the systolic blood pressure and the diastolic blood pressure, respectively. Electronic blood pressure monitors perform the above processing electronically, and use pulse sounds or pressure changes due to pulses (hereinafter referred to as pulse pressure changes) as Korotkoff sound reference signals (hereinafter referred to as reference signals) to determine the presence or absence of Korotkoff sounds. ) is detected. In any case, when mounted in a car, the cuff, rubber tube, etc. vibrate, which not only enters the Korotkoff sound sensor as noise but also enters this reference signal as noise, which can cause the blood pressure monitor to malfunction. That's what happens. A method of detecting cardiac potential as a reference signal and using a signal synchronized with heartbeat has been considered for quite some time, but this method was not practical due to the complexity of the method of detecting cardiac potential. .

In recent years, advances in electronic circuits have led to the emergence of ultra-compact and low-cost electrocardiogram detection devices, and heartbeats can now be easily used in blood pressure monitors. However, using heartbeat as a reference signal has some problems in an environment where noise, vibration, etc. are present. Since the heartbeat is constantly measured, a reference signal is created regardless of the cuff pressure, and noise can cause malfunctions even when the cuff pressure is far from the actual Korotkoff sound. In order to avoid this, it seems possible to perform a logical product between the heartbeat and a normal reference signal based on pulse sound or pulse pressure change. However, if the reference signal itself generates a spurious pulse due to vibration, if the spurious pulse and the heartbeat synchronized pulse overlap in time, multiple pulses will be generated in response to Haak's heartbeat synchronized pulse by simple AND. However, it could no longer be used as a reference signal.

An object of the present invention is to eliminate the above-mentioned drawbacks of conventional electronic blood pressure monitors and to provide an electronic blood pressure monitor that is stable against noise and vibration.

This will be explained below according to the attached drawings.

FIG. 1 is a diagram showing an example of a walking electronic blood pressure monitor, and FIG. 2 is a diagram showing the relationship between the determination method of systolic blood pressure and diastolic blood pressure and cardiac potential. First, the measurement principle will be explained. When the cuff 6 wrapped around the upper arm is gradually decompressed, a Korotkoff sound is generated. The Korotkoff sound is picked up by the Korotkoff sound sensor 1 and sent to the amplifier 21 filter 3. After amplifier 4,
The comparator 5 extracts it as a digital pulse. The pressure on the cuff 6 is converted into an electrical signal via a pressure sensor 7,
It is read into 0PU11 through AD converter 10. On the other hand, as shown in Fig. 2, pressure changes due to pulses can be seen before and after the Korotkoff sound is generated. This change is promoted by amplifying the output change of the pressure sensor 7 with an amplifier 8, and is converted into a digital pulse by a comparator 9. This is the pulse pressure change pulse P shown in Figures 4 and 5.
It is. This pulse pressure change pulse P is taken into 0PU11 as a reference signal for Korotkoff sound detection.
The CPU 11 processes each signal according to the program in the ROM 1.2, determines the systolic blood pressure and the diastolic blood pressure, and displays them on the display 14. Note that 13 is a RAM. However,
It is easy to imagine that when vibration occurs in an arm cuff, a rubber tube, a rubber ball, etc., a pressure change occurs, and the change is detected and a reference signal is output.

FIG. 3 is a block diagram showing an embodiment of the present invention. 1st
Compared to the figure, 15 cardiac potential electrodes to 22 7 lip-flops have been added.

The cardiac potential picked up by the cardiac potential electrode 15 is transmitted to the amplifier 16.
．． The signal passes through a filter 17, is further amplified by an amplifier 18, and is converted into a digital pulse by a comparator 19. This pulse causes the one-shot pulse generation circuit 20 to operate, and a heartbeat synchronized pulse with a constant width is output. Since this heartbeat synchronized pulse is connected to the reset terminal of the flip-flop 22 via the inverter 21, when the heartbeat synchronized pulse is not generated, even if the pressure of the cuff 6 fluctuates, the flip-flop 22 is The output beam remains set. While the heartbeat synchronized pulse H is being generated, the reset of the flip-flop 22 is released, and if there is a change in the pulse in this state, the clear and rough 0 toggles 22 are set and continue until the end of the heartbeat synchronized pulse H. The output Q of the flip-flop 22 is used as a reference signal.

FIG. 4 shows a timing chart of this situation.

On the other hand, as shown in FIG. 5, if the logical product P and H of the heart rate synchronized pulse H and the pulse pressure change pulse P is simply taken as a reference signal, if the pulse pressure changes due to the vibration of the cuff 6, If a spurious pulse occurs in the pulse P and overlaps with the heartbeat synchronized pulse H in time, an extra pulse will be generated as a reference signal, which will cause malfunction during blood pressure measurement. This is because when determining the diastolic blood pressure, the diastolic blood pressure at which the last Korotkoff sound occurs is determined when the reference signal is present and no Korotkoff sounds are detected for a certain period of time.

This problem could be solved by the present invention. Note that the heartbeat synchronized pulse H may be generated after a certain period of time has elapsed after the detection of the cardiac potential R wave.

It is very significant that the present invention makes it possible to measure blood pressure even under extremely adverse environments such as vibrations. This allows blood pressure to be measured even in an ambulance, etc.
There are many things that can contribute to emergency medical care, etc.

[Brief explanation of drawings]

Figure 1 shows an example of a conventional electronic blood pressure monitor, Figure 2 shows the relationship between the method for determining systolic and diastolic blood pressure and cardiac potential, and Figure 3 shows an example of the present invention. The diagrams shown in FIG. 4 are timing charts of the embodiment of the present invention, and FIG. 5 (α) (
b) is a diagram for explaining the present invention in detail. 1...Korotkoff sound sensor 2.4, 8, 16.18...Amplifier 3.17.
...Filter 5, 9, 19...Comparator 6...Archive 7...Pressure sensor 10...AD converter 11... ...... ○ PU 12 ...... ROM 13 ...... RAM 14... Display 15... Cardiopotential electrode 20... - Source Pulse generation circuit 21...Inverter 22...Furi, Pfrog P...Pulse pressure change pulse H...Heat rate synchronized pulse Q ...Flip flop output P-H...
...more than the logical product of pulse pressure change pulse and heart rate synchronized noguru Applicant: Daini Seikosha Co., Ltd. Agent Patent attorney: Tsutomu Mogami

Claims (2)

[Claims] (1) An electronic blood pressure monitor includes a cardiac potential detection circuit and a flip-flop, the cardiac potential detection circuit generates a heartbeat synchronized noggle having a certain length in synchronization with the heartbeat, and the heartbeat synchronized noggle The flip-flop is set by the existence or occurrence of a normal Korotkoff sound detection method during the generation, and after the +G beat synchronous pulse ends, the flip-flop is reset, and the presence of the Korotkoff sound is detected by the output of the flip-flop. A heart rate reference type electronic blood pressure monitor characterized by using a Korotkoff sound reference signal for determination. (2) The normal Korotkoff sound reference signal is a signal for detecting Korotkoff sounds by detecting pressure changes or pulse sounds in the arm cuff caused by the brachial artery. Heart rate reference electronic blood pressure monitor.