JPH06115B2 - Electronic blood pressure monitor - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electronic blood pressure type adopting a vibration method.

(B) Conventional technology Most conventional electronic sphygmomanometers have blood pressure due to the Korotkoff sound and cuff pressure that are generated and disappear during decompression process after pressurization is stopped by wrapping an arm band around the upper arm, pressurizing to stop blood flow. Is determined (auscultation method) or pulse wave information obtained in the decompression process is detected, and blood pressure is determined by a predetermined algorithm from the pulse wave information and the cuff pressure (vibration method).

(C) Problems to be Solved by the Invention The above-mentioned conventional electronic blood pressure monitor detects the measurement data during the depressurization process after pressurization regardless of whether the auscultation method or the vibration method is adopted. The pressure had to be increased considerably higher than the subject's systolic blood pressure. For this reason, depending on the person to be measured, there is a problem that blood pressure is generated or the time for pressurization is completely wasted, and the measurement time is lengthened.

In order to eliminate such a problem, it is sufficient to detect the measurement data at the pressurizing stage, but in principle the auscultatory method does not produce Korotkoff sounds during pressurization, and the vibrating method also performs constant speed pressurization. It was difficult and could not be put to practical use.

In view of the above, it is an object of the present invention to provide an electronic sphygmomanometer capable of constant speed pressurization and capable of determining blood pressure during pressurization.

(D) Means for Solving the Problems The electronic blood pressure monitor of the present invention includes a pressurizing means (9), an air buffer (11) pressurized by the pressurizing means, and an air buffer in the air buffer. First exhaust valve (1 for exhausting air pressure)
3) and a cuff (1) for compressing the artery of the body to be measured
A slow speed pressurizing valve (12) for gradually applying the air pressure of the air buffer to the cuff, a cuff pressure sensor (7) for detecting the pressure of the cuff, and a pulse wave in the process of slow speed pressurization by the slow speed pressurizing valve. A pulse wave detecting means (2) for detecting information, and a blood pressure determining means (5) for determining a blood pressure value based on the cuff pressure from the cuff pressure sensor and the pulse wave information from the pulse wave detecting means.
And a second exhaust valve (1) for exhausting air pressure in the cuff.
4) and.

(E) Operation In this electronic sphygmomanometer, when the pressurizing means starts operating, the air buffer is first pressurized accordingly, and the pressure of this air buffer is gradually applied to the cuff via the slow speed pressurizing valve. Therefore, the cuff is pressed slowly and at a constant speed. Then, in this slow speed pressurization process, the pulse wave is detected by the pulse wave detection means, the blood pressure is determined, and the measurement ends and the pressurization also stops when the pulse wave is no longer detected.

(F) Examples Hereinafter, the present invention will be described in more detail with reference to Examples.

FIG. 1 is a schematic block diagram of a finger pressure type electronic sphygmomanometer (finger electronic voltmeter) showing one embodiment of the present invention.

In FIG. 1, a cuff 1 is formed of a rubber bag and has a cylindrical shape that allows insertion of fingers. A pulse wave sensor 2 is attached to the cuff 1 and detected by the pulse wave sensor 2. The pulse wave signal is passed through the amplifier 3 and the A / D converter 4 to the MPU.
(Microprocessor unit) 5 is incorporated.

Further, the cuff 1 is connected to the pressure sensor by the rubber tube 6, and the cuff pressure detected by the pressure sensor 7 is amplified by the amplifier 8 so that A
It is adapted to be taken into the MPU 5 via the / D converter 4.

The pressurizing pump 9 is connected to the air buffer 11 via the check valve 10, and the air buffer 11 is connected to the cuff 1 via the slow speed pressurizing valve 12. Also,
The internal air pressures of the cuff 1 and the air buffer 11 are individually exhausted by the rapid exhaust valve 13 and the rapid exhaust valve 14.

The MPU 5 has a built-in memory for storing programs and calculated values, a function for taking in pulse wave data and cuff pressure by switching from the A / D converter 4, and turning on / off the pressurizing pump 9.
It has a function of turning on and off, a function of turning on / off the rapid exhaust valves 13 and 14, a function of determining blood pressure from pulse wave data and cuff pressure data, and the like.

Further, the determined blood pressure values, that is, the systolic blood pressure (SYS) and the diastolic blood pressure (DIA) are output from the MPU 5 and displayed on the display unit 15, and the notification sound is output from the buzzer 16 according to a command from the MPU 5. It is becoming like this.

FIG. 2 is a perspective view in which a part of the upper lid and front side plate of the electronic sphygmomanometer of the above embodiment is cut away. The display 15 is provided on the substrate 17.
And power switch key 18 and start switch key 1
9 is provided. A circuit element such as a chip of the MPU 5 is directly or indirectly mounted on the lower surface of the board 17, and a pressurizing pump 9 including a motor, an air buffer 11, and a battery are housed below the board 17. A battery unit 20 is provided. Further, the cuff 1 is connected to the air buffer 11 via the slow speed pressurizing valve 12. All the components are housed in the case 21.

Next, the operation of the electronic blood pressure monitor of the above embodiment will be described with reference to the flow chart shown in FIG.

Before starting the measurement, the operator inserts the index finger into the ring of the cuff 1 and turns on the power switch 18. With this, the operation starts, and first, step ST (hereinafter referred to as ST) 1
All display segments of all digits on the display 15 are lit for 1.5 seconds (ST2), and then the rapid exhaust valves 13 and 14 are opened (ST3), and the rapid exhaust mark on the display 15 is blinked (ST4). ). Subsequently, it is determined whether or not the cuff pressure is 0, and if it is not 0, the cuff pressure becomes 0, and the process stands by (ST5).
When the cuff pressure becomes 0, the exhaust mark is turned off (ST
6) Then, the ready mark is turned on (ST7). This allows the measurer to know that the preparation is completed. Here, if the start switch 19 is turned on, the determination in ST8 becomes YES and the preparation completion mark disappears (ST9).
Then, an LED (not shown) indicating that the measurement is in progress is turned on (S
(T10), the rapid exhaust valves 13 and 14 are closed, the pressurizing pump 9 is turned on, and the air buffer 11 is pressurized to 30 mmHg (ST11). Then, the slow speed pressurizing valve 12 is opened, and the air buffer 11 starts to pressurize the cuff 1 via the slow speed pressurizing valve 12 (ST12).
As shown in FIG. 4 (a), it gradually rises. During this ascending process, the pulse wave sensor 2 detects the pulse wave and the measurement is started. That is, the pulse number j for obtaining the amplitude of the pulse wave is set to 0 (ST1
3), and subsequently, the sample counter i within 1 beat is set to 1, the pulse number j is set to j = 1, and the maximum value xma of the pulse wave level is set.
Let x be 0 and the minimum value xmin be xsup (ST14). Here, xsup is an upper limit value that the pulse wave level x _i can take.

Then, in ST15, it is determined whether the cuff pressure is smaller than the set value. If it is larger than the set value, move to ST23, L
Turn off the ED, return to ST3, and perform the quick exhaust valve 13,
14 is opened, the exhaust mark is turned on (ST4), and exhaust is waited, but in the normal case, the determination in ST15 is YES, the pulse wave data x _i is subsequently read (ST16), and the previous pulse wave data _i-1 is set. The difference value of the current pulse wave data x _i is obtained, and it is determined whether or not the difference value is larger than the predetermined value x _t (S
T17). This determination is made to divide the pulse wave into one beat at the point where the pulse wave level changes abruptly.

If the determination in ST17 is no, move to the next ST24,
The magnitude relationship between the current pulse wave data x _i and the maximum pulse wave value x max is compared. If x _i > x max, the current pulse wave data x _i is updated and stored as a new pulse wave maximum value x max (ST25). On the contrary, if x _i ≦ xmax, ST25 is skipped and the process proceeds to ST26. In ST26, the magnitude relationship between the current pulse wave data x _i and the minimum pulse wave value x _min is compared. If x _i <x min, the current pulse wave data x _i is updated and stored as a new pulse wave minimum value x min (S
T27). On the contrary, when x _i ≧ xmin, ST27 is skipped and the process proceeds to ST28.

When the updating of the maximum value xmax and the minimum value xmin of the pulse wave data is completed in ST24 to ST27, the counter i is updated in ST28.
+1 processing is performed, and the process returns to ST15. Thereafter, x
ST24 to ST28, S until _x-1 −x _i > x _t
The processes of T15 to ST17 are repeated, and the updating process of the pulse wave maximum value xmax and minimum value xmin is continued.

When it is determined in ST17 that x _i-1 −x _i is equal to or greater than the predetermined value x _t , the buzzer 16 is sounded in ST18 to notify the pulse wave extraction. Then, the difference value Aj between the pulse wave maximum value xmax and the pulse wave minimum value xmin, that is, the pulse wave amplitude Aj is obtained (ST19).
The obtained pulse wave amplitude Aj is stored in the memory in the MPU 5. When the pulse wave amplitudes Aj are arranged corresponding to the increase in the cuff pressure, the result is as shown in FIG. 4 (b).

Next, blood pressure determination processing is performed using this pulse wave amplitude Aj as a parameter (ST20). In this blood pressure determination process, the maximum value of the pulse wave amplitude Aj is extracted, and the cuff pressure corresponding to the time when this maximum value Amax is extracted is determined as the average blood pressure P _MEAN . Then, as the cuff pressure further increased, this time the pulse wave Aj
Is decreased, the cuff pressure at the time when the pulse wave disappears is determined as the systolic blood pressure P _SYS . Next, the determined P _MEAN and P _SYS
Is substituted into P _MEAN = P _DIA + (P _SYS −P _DIA ) / 3, and the minimum blood pressure P _DIA is calculated.

Then, the process returns to ST14 until the diastolic blood pressure P _DIA is determined, the pulse number j is incremented by 1 in ST14, and then the above process is repeated to obtain the pulse wave amplitude Aj (maximum value x _{max for} each pulse wave).
And the maximum value x _min ) are calculated, and the blood pressure determination process is continued.

When the process of determining the maximum blood pressure and the minimum blood pressure is completed (ST2
1), these blood pressure values are displayed on the display 15 (ST2
2) After that, the LED is turned off (ST23), the process returns to ST3, the quick exhaust valves 13 and 14 are operated, and the measurement operation is ended.

However, the above determination algorithm is an example, and the present invention is not limited to the above algorithm.

Further, although the above embodiment has been described with respect to the finger blood pressure monitor, the present invention can be applied to an arm type electronic blood pressure monitor.

(G) Effect of the Invention According to the present invention, the pressure is applied to the cuff from the air buffer through the slow speed pressurizing valve, the pulse wave is detected in the process of pressurization, and the blood pressure is determined. Up to the value,
The measurement time is shorter than before. Further, since the measurement time is shortened and the pressurization value is low, the occurrence of depression and the like is reduced and the burden on the living body is reduced.

[Brief description of drawings]

FIG. 1 is a block diagram of an electronic blood pressure monitor for a finger showing an embodiment of the present invention, FIG. 2 is a perspective view of the electronic blood pressure monitor for the finger, and FIG. 3 is an operation of the electronic blood pressure monitor for the finger. 4 is a flow chart for explaining the operation, FIG. 4 is a time chart for explaining the operation of the electronic blood pressure monitor for the finger, and FIG. 4 (a) is a cuff pressure, FIG.
(b) is a time chart of pulse wave amplitude. 1: Cuff, 2: Pulse wave sensor, 5: MPU, 7: Pressure sensor, 9: Pressurizing pump, 11: Air buffer, 12: Fine speed pressurizing valve, 13/14: Rapid exhaust valve.

Claims (1)

[Claims] 1. A pressurizing means, an air buffer pressurized by the pressurizing means, a first exhaust valve for exhausting air pressure in the air buffer, and a cuff for compressing an artery of a body to be measured. A slow speed pressurizing valve that gradually applies the air pressure of the air buffer to the cuff, a cuff pressure sensor that detects the pressure of the cuff, and a pulse wave that detects pulse wave information in the process of the slow speed pressurization by the slow speed pressurizing valve. From a detection means, a blood pressure determination means for determining a blood pressure value based on the cuff pressure from the cuff pressure sensor and pulse wave information from the pulse wave detection means, and a second exhaust valve for exhausting the air pressure in the cuff. Become an electronic blood pressure monitor.