JPS58133235A - 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 particularly relates to an electronic sphygmomanometer capable of accurately and quickly determining diastolic blood pressure.

Generally, when measuring blood pressure, the so-called Korotkoff sound (hereinafter referred to as "sound"), the sound of blood flow colliding with the inner wall of a blood vessel, is detected, and the blood pressure value at the time of the sound is calculated as the systolic blood pressure and the sound when the K sound disappears. The blood pressure value is taken as the diastolic blood pressure. However, depending on the subject, a phenomenon in which the K sound temporarily disappears and then reappears, that is, an auscultation gap may occur, which causes erroneous determination of diastolic blood pressure.

Conventionally, therefore, after the disappearance of the K sound, the patient waits for a period of time or until the blood pressure drops to a certain extent, and then it is confirmed whether the K sound reappears or not, thereby determining the degree of hypotension. However, the above-mentioned auscultation gap does not occur in all subjects, and therefore, setting the above-mentioned waiting time to be sufficiently long will result in a significant decrease in the efficiency of blood pressure measurement work. On the other hand, if the waiting time is set short, there is a risk that the reoccurrence of the K sound may be missed, and there is a disadvantage that the accuracy of blood pressure measurement cannot be ensured.

In view of the above circumstances, it is an object of the present invention to provide an electronic blood pressure monitor that can specifically and quickly determine diastolic blood pressure. explain.

The present invention focuses on the fact that the occurrence and disappearance of the K sound have a certain relationship with the increase/decrease tendency of the pulse wave peak value,
As shown in FIG. 1, the electronic blood pressure monitor of the present invention includes a first sensor section 1 for detecting the occurrence of Korotkoff sounds, a second sensor section 2 for detecting pulse waves, and a peak of the output level of the second sensor section 2. It is equipped with a discriminating means 3 for detecting the peak value and discriminating the increasing/decreasing tendency of the peak value.

The first sensor unit 1 passes the output signal of the sound sensor 11, which is composed of a microphone or the like, through a band-pass filter 12.
This is amplified by an amplifier 13 to extract a K sound signal 11. The sound signal 11 is then input to the comparator 4,
For a signal level exceeding the reference value Vo, a pulse output 12 of [1-I J level is obtained.

The second sensor section 2 filters the output signal of the pulse wave sensor 21, which includes a pressure sensor, a microphone, etc., through a bandpass filter 22.
is passed through and amplified by an amplifier 23 to extract a pulsating pulse wave signal J1. This pulse wave signal j1 is an analog
The digital converter 5 samples and converts it into a digital data signal j2, and this data signal J2 is docked into the memory included in the microprocessor 6 system. As will be described later, this data is read into the microprocessor 6, and the peak value of the pulse wave signal Jl is sequentially checked, and it is determined whether the peak value tends to increase or decrease.

Figure 2 shows the fluctuation situation of the peak value level (the second
(1)) and the +1il pulse output applied to the K sound (shown in FIG. 2 (2)). In the figure, the pulse wave peak value repeatedly exhibits an increasing tendency (indicated by X in the figure) and a decreasing tendency (indicated by Y in the figure), and the K sound occurs during this increasing trend, and The blood pressure value at the time is determined as the maximum blood pressure Pmax. Additionally, the sound disappears while the pulse wave peak value is decreasing, and the blood pressure value at the time of its disappearance is determined to be the diastolic blood pressure Pm1n. However, if the sound temporarily disappears while the peak value is increasing, this can be checked by auscultation. It is recognized as gap S.

FIG. 3 shows an operation flow for determining the diastolic blood pressure, including an operation for determining the auscultation gap.

In FIG. 3, step 71 is to determine whether the systolic blood pressure has been determined, and step 71 is determined by the generation of the K sound.
1 becomes YES, and the process proceeds to the next step 72.

Furthermore, in a state where no sound is generated, the systolic blood pressure has not yet been determined, and therefore the determination in step 71 is No, and the process waits for the systolic blood pressure to be determined.

Next, in step 72, the pulse wave signal is converted into a digital data signal, and further, in step 73, the peak values of the pulse wave signal are sequentially checked. Then, the data determined to be the peak value in step 73 is processed in step 74.
It is set in a register Mn built into the microprocessor 6, and the previous data being set in the register Mn is moved to another register Mn-+.

On the other hand, the interval between sounds is constantly monitored by a timer, etc.
When the generation of sound ceases for a certain period of time due to time-up, the determination in step 75 becomes YES, and in the next step 76, it is determined whether or not the disappearance of the sound is due to the auscultation gap. That is, step 76 uses the data contents of registers Mn and Mn-+ to determine whether the pulse wave peak value tends to increase or decrease.
Since an increasing tendency can be determined when the data content is equal to or greater than n-+, it is determined that the above-mentioned cessation of sound is due to the auscultation gap, and therefore the diastolic blood pressure measurement operation is continued.

On the other hand, when the contents of register Mn are smaller than the contents of register Mn-+, it is determined that the peak value tends to decrease, and the determination in step 76 becomes NO, and the process proceeds to step 77. In this step 77, it is checked whether the difference in data contents between the register Mn and the register Mn-+ is equal to or less than a certain value α'-, and when the determination in step 77 is YES, the point at which the sound disappears is Determine the diastolic blood pressure while step 77
When the determination is No, the discontinuation of the K sound is recognized as being caused by the auscultation gap, and the diastolic blood pressure measurement operation is continued.

Since the present invention is configured as described above, it is possible to easily determine whether the disappearance of the K sound is due to the auscultation gap, and therefore, the diastolic blood pressure can be accurately and quickly determined without misidentifying it. It has a great effect.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the circuit configuration of an electronic blood pressure monitor according to the present invention, FIG. 2 is an explanatory diagram showing the principle of the present invention, and FIG. 3 is a flowchart showing the operation of the electronic blood pressure monitor. ■...First sensor part 2...Second sensor part 3...Discrimination means patent applicant Tateishi Electric Co., Ltd.

Claims (1)

[Claims] A first sensor section that detects the occurrence of Korotkoff sounds, a second sensor section that detects pulse waves, and a determining means that sequentially detects peak values of the output levels of the second sensor sections and determines trends in increases and decreases in the peak values. An electronic blood pressure monitor comprising: