JPS63153041A - 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] Industrial applications The present invention relates to an electronic blood pressure monitor.

BACKGROUND OF THE INVENTION The configuration of a conventional electronic blood pressure monitor is shown in FIG. 4, and its measurement principle will be explained. First, the arm cuff 1 is attached to the upper arm of a human body. At that time, the sound sensor 7 built into the arm cuff 1 is aligned with the position of the artery in the upper arm of the human body. Next, air is blown into the cuff through the rubber tube using the rubber bulb 2 to pressurize it to a constant pressure. When the air supply by the rubber bulb 2 is stopped, a small amount of air is discharged from the micro-exhaust valve built into the rubber bulb,
The pressure within the cuff 1 gradually decreases. Further, the pressure within the cuff 1 is detected by a pressure ejection circuit 4 connected to the rubber tube 3, and the output of the pressure detection circuit 4 is a digital signal that is input to the control section 6. Furthermore, when the pressure of the arm cuff 1 is at its maximum value, the artery in the upper arm is compressed and the blood is blocked, so the output of the sound sensor 7 on the artery is a low frequency and low sound, but as the pressure decreases, blood begins to flow. A Korotkoff sound appears in the output of the sound sensor 7, and as the pressure further decreases, the Korotkoff sound disappears.In addition, the output voltage of the sound sensor is amplified by an amplifier circuit 8, and the output voltage of the amplifier circuit 8 is used by a filter circuit 9. to detect Korotkoff sounds. A comparator 1o inputs the output of the filter circuit 9, converts it into a digital signal, and inputs the output to the control unit 5,
In the control unit 5, the output of the pressure detection circuit 4 when the output of the comparator 10 becomes No.
The output of the pressure detection circuit 4 when the angle becomes low is displayed on the display 7 as the diastolic blood pressure.

Problems to be Solved by the Invention However, the conventional configuration described above requires alignment between the sound sensor and the artery when the arm cuff is worn, which is inconvenient. Additionally, since Korotkoff sounds are detected using a sound sensor, electrical noise or noise can cause malfunctions.

Therefore, the present invention allows blood pressure to be easily measured without a microphone.
Furthermore, the purpose is to provide a low-cost blood pressure monitor.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides an arm cuff to be worn on the upper arm of a human body, and a pressurizer that supplies air into the arm cuff to apply pressure to the upper arm of the human body until blood ischemia is achieved. means, a slight evacuation means that gradually evacuates and reduces the pressure, an instantaneous pressure detection means that detects the pressure in the cuff at regular time intervals, and an exhaust pressure detection means that detects the evacuation pressure by the micro evacuation means; A first memory that stores a pressure value when the rate at which the instantaneous pressure decreases during micro-evacuation begins to decrease.
storage means, and after the rate at which the instantaneous pressure decreases during slight evacuation begins to decrease, the maximum value of the difference between the exhaust pressure and the instantaneous pressure is stored;
a second storage means for storing the magnitude of the blood vessel sound generated during microevacuation, and converting the previously stored value of the blood vessel sound to 1/K2 times when the magnitude of the blood vessel sound exceeds a certain value; a converting means for converting the value of the subsequent blood vessel sound to 1/K2; a determining means for determining a blood pressure value from the change in the blood vessel sound and the pressure value stored in the first storage means; and a determining means for displaying the blood pressure value. It consists of a display means.

Operation The present invention has the above-described configuration, which eliminates the need for a K-sound sensor, and eliminates the need for positioning, thereby reducing costs. By detecting the magnitude of the blood vessel sound as the difference between the exhaust pressure and the instantaneous pressure, it is possible to accurately detect and obtain an accurate blood pressure value regardless of changes in the exhaust speed.

In addition, the volume of blood vessel sounds varies greatly depending on the person, but by detecting the smallest person as a standard, and when the volume of blood vessel sounds is above a certain level, it is reduced and stored, making it possible to accurately measure all people. Moreover, it can be configured with a small storage capacity.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 3. 1 is a cuff that is worn on the upper arm of the human body, 2 is a rubber ball that functions as a pressure means and a micro-evacuation means, and this rubber ball 2
Air is blown into the cuff through the rubber tube 3 and pressurized to a constant pressure.
The pressure is gradually reduced by evacuation through a micro-exhaust valve (not shown) built into the rubber bulb 2.

Further, the pressure detection circuit 30 functions as instantaneous pressure detection means and exhaust pressure detection means, and inputs these detected pressures to the control section 6. Here, the pressure detection circuit 30 has an output of 12 to 9 pits because it simultaneously detects minute changes in pressure due to blood vessel sounds, unlike the 8 to 9 pit output of the conventional pressure detection circuit that detects only the pressure value inside the cuff. Use one with a high resolution of 16 bits.

Next, a method of processing the instantaneous pressure signal detected by the control section 6 will be explained with reference to FIGS. 2 and 3.

Note that the period from the completion of pressurization to the completion of measurement is referred to as the measurement mode, and the period thereafter until the completion of exhaustion is referred to as the exhaust mode.

In the measurement mode, first determine the initial value (step 11)
), the instantaneous pressure signal Pi during slight evacuation is detected at regular intervals (step 12.13). Next measured instantaneous pressure signal P
From i and the previous value Pi, and the value Pi 2 before the previous time, Pi
It is determined whether the change value of -+-Pi is 1 or more smaller than the change value of Pi-2Pi-1 (Step 14). If not satisfied, and if the front of the first blood vessel is not detected, the pumping speed is Calculate DP (step 15.18)
. Then, return to step 12 and repeat. When step 14 is satisfied, Pi I is stored as the pressure value 1)t when the blood vessel sound occurs. At the same time, i-1 is stored as MW (
Step 17). Next, at the time of NZ2, the exhaust pressure DPN for 1 step is DP)l=(PH-1PM)/(M-
Mt1) (step 18). Next, the instantaneous pressure signal Pi is measured (step 19.20). Next, the instantaneous value DQi of the pressure change corresponding to the size in front of the blood vessel is DQ
i=Pi−PN+DPIX(iM)l) (step 21). Next, it is determined whether DQi has reached the maximum value, and the process returns to step 19 and repeats until it reaches the maximum value (step 22). If step 22 is satisfied,
The prevascular size Q)l is QM= (DQi MAW/
k 2 ) (step 23).

Next, it is determined whether QN exceeds the memory allowable value QM (step 24). When QN>QM, 2 is set to 2 (step 25). Next, all the QNs stored so far are divided by 2 and stored again (step 26). Next, 1 is added to H (step 27). If Q<QM, proceed to step 2. Next, determine the maximum value of Q) l,
If the maximum value has not been reached, return to step 12 and again.
The front of the blood vessel is detected (step 28). Q in step 28
When the maximum value of H is detected, it is determined in the blood pressure determination process whether the diastolic blood pressure has been reached, and if the blood pressure is not satisfied, the process returns to step 12 and the blood vessel front is detected again (step 29). Next, in step 29, when the diastolic blood pressure is determined, the systolic blood pressure is determined,
Display as blood pressure value.

Effects of the Invention As described above, the present invention eliminates the need for a K sound sensor, eliminates the need for alignment, and eliminates the need for a K sound sensor, an amplifier circuit, a filter circuit, and a comparator, resulting in cost reduction. be done.

In addition, the size in front of the blood vessel can be easily detected as an increase in pressure value, and can be detected without being influenced by the pumping speed, so that accurate blood pressure can be measured. Moreover, the present invention provides an electronic blood pressure monitor that allows anyone to accurately measure blood pressure by correcting the size of the front blood vessel using the maximum value.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an electronic blood pressure monitor according to an embodiment of the present invention, FIG. 2 is a waveform diagram showing the size of the front blood vessel from the pressure value of the present invention, and FIG. 3 is a diagram of the electronic blood pressure monitor according to the present invention. A flowchart showing the control, and FIG. 4 is a block diagram showing the configuration of a conventional electronic blood pressure monitor. 1... Bracelet, 2... Rubber ball (pressurizing means, fine evacuation means), 5... Control unit, 3o...
・Pressure detection circuit (instantaneous pressure detection means, exhaust pressure detection means). Name of agent: Patent attorney Toshio Nakao and one other person? −
Comb body, 3-Com tube Figure 1? j Shi-J Shout Rro- Ku-ba Figure 3

Claims (2)

[Claims] (1) a cuff to be worn on the upper arm of a human body, and a pressurizing means for supplying air into the cuff to pressurize the upper arm of the human body until blood ischemia is achieved;
a minute evacuation means that gradually evacuates and depressurizes; an instantaneous pressure detection means that detects the pressure within the cuff at regular intervals; an exhaust pressure detection means that detects the evacuation pressure by the minute evacuation means; and the instantaneous pressure. a first storage means for storing a pressure value when the rate at which the instantaneous pressure decreases during fine evacuation starts to decrease; a second storage means for storing the maximum value of the difference as the magnitude of the blood vessel sound generated during microextraction; Convert to K_2 times, and the subsequent value of blood vessel sound is also 1/K
_2; a determination means for determining a blood pressure value from the change in the blood vessel sound and a pressure value stored in a first storage means; and a display means for displaying the blood pressure value. (2) The determining means determines that the pressure at which the magnitude of the blood vessel sound increases with a decrease in the instantaneous pressure in the arm cuff and becomes equal to or higher than a predetermined ratio of the maximum value of the blood vessel sound is the systolic blood pressure, and The electronic sphygmomanometer according to claim 1, wherein the electronic blood pressure monitor is configured to determine the blood pressure value by determining the diastolic blood pressure as the pressure that decreases as the pressure within the band decreases and becomes equal to or less than a predetermined ratio of the maximum value of the blood vessel sound. .