JPH0241966B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a sphygmomanometer, and particularly to a sphygmomanometer that notifies when the pulse generation interval is equal to or greater than a predetermined value.

[Background technology]

Generally, when measuring blood pressure, it is necessary to do so in a resting state, and accurate measurements cannot be made if the measurement is made when the heartbeat is not stable, such as immediately after strenuous exercise. Furthermore, even if the subject is not immediately after exercise, it is desirable to take the measurement after the subject has rested for about 5 minutes. Conventional blood pressure monitors cannot determine whether or not the subject is at rest when measuring blood pressure, and they measure blood pressure even when the heartbeat is not stable, resulting in incorrect blood pressure values being presented. There was a problem.

[Purpose of the invention]

The present invention has been made in view of the above points, and its purpose is to determine whether blood pressure measurement is being performed in a resting state, and to notify the subject if the blood pressure measurement is not in a resting state. An object of the present invention is to provide a sphygmomanometer that prevents erroneous blood pressure values from being presented.

[Disclosure of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 3. 1 is a cuff band attached to the upper arm of a human body A, and air is sent into the cuff band 1 by a pressurizing pump 4. A rapid exhaust valve 5 is provided between the pressurizing pump 4 and the cuff band 1 to rapidly exhaust air from the cuff band 1 after blood pressure measurement is completed or in an abnormal situation.
is connected to the cuff band 1, and a slow exhaust valve 6 is connected to the cuff band 1, which gradually exhausts air from the cuff band 1 when measuring blood pressure after pressurizing the cuff band 1 to a predetermined pressure. Further, a pressure detection section 7 consisting of a bellows 8 and a differential transformer 9 is connected to the cuff band 1, and the pressure of the cuff band 1 is detected by the pressure detection section 7. Reference numeral 12 denotes a microphone for detecting Korotkoff sounds and pulse sounds, and is attached to the cuff band 1. The output of the microphone 12 is amplified by an amplifier 13, and then inputted to a band pass filter 14 for passing Kotlokoff sounds and a low pass filter 15 for passing pulse sounds to remove noise, and further reduce the level. Outputs of a predetermined level or higher are converted into constant pulse signals in the detectors 16 and 17, and then input to a Korotkoff sound discriminating circuit 18 constituted by an AND gate. The Korotkoff sound discrimination circuit 18 selects only the Korotkoff sound component obtained as the output of the level detector 16 and the pulse sound component obtained as the output of the level detector 17, in which both are synchronized, as a true Korotkoff sound. It is output as a signal. 10 is an A/D converter that converts an analog value from the pressure detection section 7 into a digital value, and the pressure value of the cuff band 1 detected by the pressure detection section 7 is converted into a digital signal and sent to the operation control circuit 11. Output. The operation control circuit 11 operates the rapid exhaust valve 5 to exhaust the air from the cuff band 1 after blood pressure measurement is completed, and receives the output signals from the Korotkoff sound discrimination circuit 18 and the A/D converter 10 to It outputs signals of high blood pressure and diastolic blood pressure to a display circuit 19, and the display circuit 19 is composed of, for example, a 7-segment, 3-digit display element, and displays blood pressure values,
Digitally displays pulse rate, etc. As described above, the Korotkoff sound discriminating circuit 18 outputs only the Korotkoff sound component and the pulse sound component that are synchronized with each other, so it constitutes the detection circuit 2 for detecting the pulse. There is. FIG. 2 shows a graph showing changes in pulse rate depending on the condition of the subject, and FIG. 3 shows the output waveform of the detection circuit 2. . Here, the a section represents during exercise, the b section represents after exercise, and the c period represents a resting state. The output of the detection circuit 2 is input to a pulse interval measuring circuit 21, and as shown in FIG. 3, the interval between the rises of each pulse signal is measured as the pulse generation interval. The output of the pulse interval measuring circuit 21 is input to the pulse rate calculation circuit 25 to calculate the pulse rate per minute, which is displayed on the display circuit 19. The pulse interval data T measured by the pulse interval measuring circuit 21 is stored in the first to sixth memory circuits 3 in the order of measurement.
are stored in the data storage units 31 to 36 of. Thereafter, in the comparator circuit 22, the pulse interval data first stored in the storage section 3, that is, the data storage section 3
The data T1 stored in ₁ and the pulse interval data subsequently stored in the storage unit 3, that is, the data storage unit 3
The data T ₂ -T ₆ stored in the data T 2 - 36 are sequentially compared, and the difference between the data T ₁ and the data T ₂ -T ₆ is outputted to the discrimination circuit 23, respectively. The discrimination circuit 2
3 is input with the data T ₁ of the data storage section 31, and the discrimination circuit 23 calculates and stores a value of 25% of the data T ₁ , compares this value with the output of the comparison circuit 22, and determines the value of the data T 1. When the output of the comparison circuit 22 is equal to or greater than 25% of the data _T1 , a signal is output to the annunciator 24. Here, it is known that fluctuations in pulse interval data under normal resting conditions are within a range of ±25%. The alarm device 24 includes, for example, a buzzer, a lamp, etc., and when it receives the output signal of the discrimination circuit 23, it operates the buzzer, lamp, etc. to notify the user. When blood pressure is measured using the blood pressure monitor of this embodiment, for example, in the post-exercise state in section b shown in FIG. 2, the pulse generation interval T ₁ to
As is clear from section b in Figure 3, Tn is getting longer and longer, and the pulse interval T is fluctuating by more than ±25%, so this blood pressure monitor operates the buzzer and lamp of the alarm 24. Therefore, the patient is informed that the patient is not in a resting state, that is, a state in which accurate blood pressure measurement is impossible, and the patient is urged to stop the measurement.
As mentioned above, the fluctuation of the pulse interval can be used to judge the resting state.
The determination of the resting state is accurate because the determination is based on whether it is within the 25% range. In this embodiment, the pulse interval data measured by the pulse interval measurement circuit 21 is temporarily stored in the data storage units 31 to 36 of the storage circuit 3, and then the comparison circuit 22 compares data T ₁ and data T _2.
-T6 , and after this, when the pulse interval is newly measured by the pulse interval measuring circuit 21, the first data _T1 stored in the data storage section 31 is compared as shown in FIG. Along with being erased,
Data T ₂ stored in data storage units 32 to 36
~ _T6 are transferred to the data storage units 31 to 36 in order to become data _T1 to _T5 , and the data of the newly measured pulse interval is stored in the data storage unit 36 to become data _T6 . After data as above
T ₁ and data T ₂ to _{T 6} are compared in a comparator circuit 22 . Thereafter, by repeating the above-described operations, it is determined whether or not the patient is in a resting state. In addition, the discrimination circuit 23 is directly connected to the display circuit 19 instead of the alarm 24 of this embodiment, and when a signal is output from the discrimination circuit 23, the segments of the display element of the display circuit 19 are decremented, or characters are displayed. The notification can also be made by lighting up the display.

〔Effect of the invention〕

As described above, the present invention includes a detection circuit that detects a pulse, a pulse interval measurement circuit that measures the interval between pulse occurrences in response to an output signal of the detection circuit, and a pulse interval measurement circuit that measures pulse intervals sequentially measured by the pulse interval measurement circuit. a memory circuit that stores data in a plurality of data storage units; a comparison circuit that sequentially compares the first pulse interval stored in the memory circuit with a plurality of pulse intervals that are subsequently stored; comprising a discrimination circuit that outputs a signal when a difference between a pulse interval initially stored in the storage circuit and a pulse interval subsequently stored is equal to or greater than a predetermined value; and an alarm that receives the output of the discrimination circuit and notifies you; When the measured number of pulse intervals to be stored exceeds the number of data storage parts of the storage circuit, the second pulse interval is stored in the first data storage part that stores the pulse interval first, and in the data storage part that stores the second pulse interval. the pulse interval stored in the next data storage unit is transferred to and stored in the previous data storage unit;
The first measured pulse interval is stored in the data storage unit that stores the final pulse interval, so if you measure blood pressure immediately after strenuous exercise or when your heartbeat is not stable, This has the effect of notifying the subject that he or she is not in a resting state, prompting the subject to stop the measurement, and preventing the presentation of erroneous blood pressure values.

You can always judge whether the latest pulse interval measurement data is in a resting state and can also compare it with the measurement data from a while ago, so even if a little time has passed, the state will continue to be the same as the measurement data from a while ago. It is possible to determine whether the patient is in a resting state based on the latest measurement data, and it is possible to more accurately determine whether the patient is in a resting state based on the latest measurement data.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a graph showing changes in pulse rate depending on the condition of the subject, and FIG. 3 is a diagram of the output waveform of the detector. 2...Detector, 3...Storage circuit, 21...Pulse interval measurement circuit, 22...Comparison circuit, 23...Discrimination circuit, 24...
Alarm.

Claims (1)

[Scope of Claims] 1. A detection circuit that detects a pulse; a pulse interval measurement circuit that receives an output signal of the detection circuit and measures a pulse interval; and a plurality of pulse intervals sequentially measured by the pulse interval measurement circuit. a comparator circuit that sequentially compares the first pulse interval stored in the memory circuit with a plurality of pulse intervals subsequently stored in the memory circuit; and a comparator circuit that receives the output of the comparator circuit to a discriminating circuit that outputs a signal when the difference between the pulse interval initially stored in the storage circuit and the pulse interval subsequently stored is equal to or greater than a predetermined value; and an annunciator that receives the output of the discriminating circuit and notifies you; When the number of measured pulse intervals to be stored exceeds the number of data storage sections of the storage circuit, the first data storage section that stores the first pulse interval and the second data storage section that stores the second pulse interval are stored. The pulse interval stored in the next data storage section is transferred and stored in the previous data storage section, and the pulse interval stored in the next data storage section is sequentially transferred and stored in the data storage section storing the final pulse interval. A blood pressure monitor that stores the most recently measured pulse interval. 2. A patent claim characterized in that the discrimination circuit outputs a signal when the difference between the pulse interval initially stored in the memory circuit and the pulse interval stored thereafter is ±25% or more of the pulse interval stored first. The blood pressure monitor according to item 1.