JPS63311929A - Digital electronic hemomanometer - Google Patents

Abstract

PURPOSE:To accurately measure blood pressure by a measuring person in a comfortable position, by correcting a blood pressure value corresponding to the relative height position of a cuff to the heart and displaying this corrected blood pressure value as a measured value. CONSTITUTION:A forefinger is inserted in a finger cuff 2 and the position to be held of the cuff 2 to the heart is judged to close an offset change-over switch 7. When a measuring person inserts his finger in the finger cuff 2, the light from a light emitting element 15 is blocked by the finger to start the rotation of a pump motor 26 and the max. pressurizing time is set. When cuff pressure reaches 170mmHg, the pump motor 26 is stopped and the finger cuff 2 enters slow speed air discharge from a slow speed discharge valve 29. Next, the light emitting element 15 for detecting a pulse wave is allowed to light and, when the pulse wave is detected, the amplitude of the pulse wave at that point of time is stored and a blood pressure value is calculated and, further, a pulse rate is calculated and the cuff pressure at the point where the pulse wave amplitude value is obtained is set to the max. blood pressure and the cuff pressure corresponding to the max. amplitude value is set to average blood pressure and the min. blood pressure is calculated from the max. blood pressure and the average blood pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an electronic finger blood pressure monitor, and particularly to an electronic finger blood pressure monitor that has been devised to improve measurement accuracy.

(b) Conventional technology In general, an electronic finger blood pressure monitor includes a roughly cylindrical cuff for compressing the finger, an air pressure supply means such as a motor pump that supplies air pressure to the cuff, and a device that gradually controls the air pressure of the cuff. It consists of an air pressure adjustment means such as a slow exhaust valve that changes the air pressure, a pressure sensor that detects the pressure in the cuff, a light emitting element, and a light receiving element. a photoelectric sensor that receives light from the cuff; a pulse wave extraction means that extracts a pulse wave component from the output of the light receiving element during the process of changing the air pressure of the cuff; The blood pressure determining means determines the blood pressure based on the pulse wave information, and the display device displays the determined blood pressure value.

When measuring blood pressure with this electronic finger sphygmomanometer, with the finger inserted through the cuff, the cuff is pressurized using the air pressure supply means to compress the finger and stop blood flow, and then the cuff pressure is gradually adjusted using the air pressure adjustment means. During the slow decompression process, the cuff pressure is continuously detected by a pressure sensor, and a pulse wave amplitude data string is obtained by a photoelectric sensor and a pulse wave extraction means, and a predetermined algorithm is applied to this pulse wave amplitude data string. The blood pressure value is determined by referring to the cuff pressure and displayed on the display.

(c) Problems to be Solved by the Invention With the above-described conventional finger electronic blood pressure monitor, accurate measurement results could not be obtained unless the finger was measured at the same height as the heart. Therefore, if you want to make accurate measurements,
The cuff had to be kept at the level of the heart, which sometimes forced the person taking measurements into an uncomfortable position.

However, if you ignore the height of the cuff and place the cuff at a higher ps position or lower than the heart and insert your finger to measure, there will be a measurement error (for example, if you measure at a position 10 marks lower than the heart, the measured value will be about 8mm 1g higher) And conversely, from the heart, 100n
If measured at a high position, the measured value will be approximately 8 mmHg lower)
This caused the problem that accurate blood pressure measurement could not be carried out.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide an electronic finger sphygmomanometer that allows a person to measure blood pressure accurately while maintaining a comfortable posture.

(d) Means and operation for solving the problems The electronic finger blood pressure monitor of the present invention includes a cuff (2) for compressing the finger;
Air pressure supply means (26) that supplies air pressure to the cuff; air pressure adjustment means (29) that gradually changes the air pressure of the cuff; on the left, a pressure sensor (2) that detects the pressure of the cuff;
3), and pulse wave extraction means (15, 16, 19, 20,
21); blood pressure determination means (12, Sr12) for determining blood pressure based on the cuff pressure detected by the pressure sensor and pulse wave information extracted by the pulse wave extraction means; a cuff position input means (7) for inputting a set height position of the cuff relative to the heart, and a cuff height input by the cuff position input means; blood pressure correction means for calculating a correction value according to the position to the blood pressure value determined by the blood pressure setting means
12,5T34.5T35).

In this electronic finger sphygmomanometer, when measuring blood pressure, the measurer uses the cuff position input means to preset and input the position where the measurer places his or her finger, and therefore the position where the cuff is held. For example, 10 cm from the heart
If you hold the cuff in a low position and insert your finger for measurement, enter that position, that is, =10ci. When blood pressure measurement is started and the blood pressure determining means determines, for example, the systolic blood pressure and the diastolic blood pressure, the blood pressure value is supplemented with a correction value corresponding to the cuff position input in advance by the blood pressure value correcting means, for example, 10 cm from the heart. For lower positions, add -8mm/1g.

This cancels out the fact that the blood pressure was measured at a position 10 cm lower than the heart, resulting in a higher result of +8 mm and 11 g, and the display shows an accurate blood pressure value.

(e) Examples The present invention will be explained in more detail with reference to Examples below.

FIG. 2 is an external perspective view of an electronic finger blood pressure monitor showing an embodiment of the present invention. In the figure, a finger cuff 2 is attached to a main body case 1, and the finger cuff 2 is attached so that it can be opened and closed by a predetermined angle about a point 2a as a fulcrum.

When the finger cuff button 3 is operated, the tip end 2b of the finger cuff 2 is folded out from the main body case 1 as shown in the figure, making it easy to insert a long finger into the finger cuff 2. On the surface of the main body case l, there is a display 4,
It is equipped with a power switch 5, a start switch 6, and an offset changeover switch (cuff position input means) 7. Offset selector switch 7 is +2, +1.0, -L-2
, O is when the position of the cuff 2 is at the level of the heart, +1 is when the position is 10 cm higher than the heart, +2 is when the position is also 20 cm higher than the heart, and -
1 is selected when the height is to be 10 cm lower than the heart, and -2 is selected when the height is to be -20 cm lower than the heart. Inside the main body case 1, an electronic circuit section, a pump and a motor for driving the pump, a power source battery, etc., which will be described later, are housed.

FIG. 1 is a circuit block diagram of the electronic blood pressure monitor borrowed from the embodiment. When the power switch 5 is turned on, the power supply voltage is supplied from the power supply circuit 11 to the MPU 12 and other electronic circuit sections, and the motor drive circuit 25 is operated as required under the commands of the MPU 12. , pump motor 26
Rotate to pressurize finger cuff 2, and if necessary, press MP
The rapid exhaust valve drive circuit 27 is driven under the command of U12, and the valve 28 is opened so that the pressure in the finger cuff 2 can be rapidly exhausted. Furthermore, the air pressure in the air system is gradually exhausted by the slow exhaust valve 29, and the pulse wave is measured during this slow pressure reduction process.

The MPU 12 outputs a digital value indicating the lighting level of the light emitting element 15, converts it into an analog value with the digital/analog converter 13, inputs a predetermined voltage to the LED drive circuit 14, and operates the LED drive circuit 14 to emit light. The element 15 is turned on. The pressure in the finger cuff 2 is detected by the semiconductor pressure sensor 23, and is taken into the MPU 12 via the amplifier circuit 24 and the A/D converter 22 and stored. On the other hand, the output of the light receiving element 16 of the photoelectric sensor is transmitted to the amplifier 19, the filter circuit 20, the amplifier circuit 21, and the A
/D converter 22 or directly A/D converter 2
2 and is configured to be taken into the MPU 12 through the MPU 12. The reason why the output of the light receiving element 16 is directly input to the MPU 12 through the A/D converter 22 is to obtain the DC component of the output of the light receiving element 16. The lighting level of the light emitting element 15 is switched. On the other hand, the output of the light receiving element 18 for finger detection is also M
It is designed to be taken into the PU12.

The MPU 12 has a function of determining blood pressure such as systolic blood pressure and diastolic blood pressure based on the cuff pressure and pulse wave amplitude that are taken in time-sequentially during the slow evacuation process. , has a function of adding a correction value to the determined blood pressure value and outputting a corrected blood pressure value corresponding to the position of the cuff. The corrected blood pressure value is displayed on the display (LCD) 4.

Next, the operation of measuring blood pressure using the electronic blood pressure monitor borrowed from the above embodiment will be described.

First, as shown in FIG. 2, the finger cuff 2 is opened from the main body by operating the button 3, and the index finger, for example, is inserted into the finger cuff 2 as shown. In this state, turn on the power switch 5. At this time, the measurer determines at what position the cuff 2 should be held relative to the heart. For example, if the cuff 2 is to be held l0C11 lower than the heart, the offset selector switch 7 is set to -1.

When the power switch 5 is turned on, the processing operation of the MPU 12 starts, and as shown in FIG.
(referred to as T)1]. Subsequently, all segments of the display 4 are turned off, and after checking the operation of the display 4 (Sr1), the heart (9) mark on the display 4 is turned on (ST3').

When this heart mark is lit, it indicates that the preparation of the electronic circuit section of the meter is completed, and the measurer then turns on the start switch 6 (Sr4). As a result, Sr4's “
The determination as to whether the start switch has been pressed becomes YES, and then the heart mark on the display 4 goes out (Sr5
). Next, a finger was inserted.

It is determined whether or not there is one (Sr1). This determination is made based on whether the light emitting element 15 is turned on and the light entering the light receiving element 18 is blocked. That is, when the measurer inserts his or her finger into the finger cuff 2, the light from the light emitting element 15 is blocked by the finger, so that finger insertion is detected. In the state where the finger is inserted as shown in FIG. 2, this determination becomes YES and an upward arrow is lit on the display 4 (Sr7). This upward arrow is a display indicating the start of pressurizing operation, and at the same time closes the valve 28 (Sr1
). Further, the motor drive circuit 25 is activated to start rotating the pump motor 26 (Sr1). Then, the maximum pressurizing time is set (ST10). This pressurization maximum time is for setting the time required for pressurization. After the pressurizing operation is started, it is further determined at 5TII whether or not the finger has been inserted again, and if the finger is still inserted,
Pressure will continue to be applied. Then, it is determined whether the cuff pressure is 170 mmHg or more (ST12
). In the initial pressurization state where the cuff pressure has not reached 170 mm 1 g or more, the determination is NO, and then the process moves to 5T13, where it is determined whether the maximum pressurization time is over. If the maximum pressurization time has not exceeded, the process returns to 5TII, that is, the pressurization operation continues as it is. The reason why it is determined whether the cuff pressure has reached 170 mm11 g or more at 5T12 is because this 170 nmHg is set as the target pressurization value.

When the cuff pressure reaches 170 mm/g, the determination in 5T12 becomes YES, and the pump motor 26 is stopped (5T14), and the upward arrow on the display 4 is turned off (ST1).
5). This completes pressurization, and the finger cuff 2 is closed to the slow exhaust valve 29.
Enter slower exhaust speed. After that, to detect the pulse wave, turn on the light emitting element 15 (5T16) and wait for 2 seconds (ST1
7), then determine whether a pulse wave is detected (STlB
). Cuff pressure is 20mm when pulse wave is not detected.
Please judge whether it is 11g or less (ST 24)
, 5T18 pulse wave detection processing is performed until it becomes 20 mm 1 g or less. If a pulse wave is still not detected even after the cuff pressure has decreased to 20 mmHg, the indicator 4 indicates that there is an abnormality.
E (error) is displayed (ST25), and the process moves to 5T27. When a pulse wave is detected in 5T1B, the heart mark is lit for 0.2 seconds in 5T19, and the pulse wave amplitude at that time is memorized. 5T21), and repeats the pulse wave detection process until the pulse wave amplitude data (N pieces) are collected. When the data is complete, that is, when the judgment of Sr11 is YES, Sr12 calculates the blood pressure value, further calculates the pulse rate (ST23), and 5T
Move on to 27. The algorithm for blood pressure calculation (blood pressure determination) is
There are various methods, but for example, the cuff pressure at the point where the pulse wave amplitude value was obtained is taken as the systolic blood pressure, the cuff pressure corresponding to the maximum amplitude value is taken as the average blood pressure, and the diastolic blood pressure is calculated from this systolic blood pressure and the average blood pressure. etc. are processed.

When the measurement is completed, the pump motor 26 is stopped at 5T27, the valve 28 is opened in the same way, and rapid exhaust is started (S
T2B), the light emitting element 15 is turned off (ST29), and the downward arrow is turned on (S・T30). This downward arrow is a display indicating rapid exhaust. Then, it is determined whether the cuff pressure has become 5 mmHg or less.
), when it becomes less than 5 mm 1 g, the downward arrow turns off (ST32) and it is determined whether there is a measurement result or not. 5T33
), if there is a normal measurement result rather than an error,
Read the state of the offset selector switch 7 (ST34),
An offset (correction value) according to the injection state is added to the systolic blood pressure and diastolic blood pressure values determined in 5T22 (ST35
). For example, when the offset selector switch 7 is set to -1, the offset is 18 cylinders Hg, and this -
8mmHg is added. Place finger cuff 2 10cm from the heart.
If the blood pressure is measured at a low position, the measured value will be +8 Hg higher, so by adding -8 Hg, the higher value will be offset and an accurate blood pressure value will be obtained. This corrected blood pressure value is displayed on the display 4 (ST36), and the process returns to Sr1. If there is no measurement result, that is, there is an error, the process returns to Sr1 and prepares for the next measurement.

In addition, in the above embodiment, the offset changeover switch 7
uses a 5-stage switch, but of course a 3-stage switch may also be used. Furthermore, although each step is set to 10 cm, it may be made even finer than 5 cm, or the position of the cuff may be input in a continuously variable manner using a knob or the like.

(F) Effects of the Invention According to the present invention, the position of the finger cuff is input and the blood pressure value corrected according to the input position is displayed. Even when the cuff is placed on the device, accurate blood pressure measurements can be made at all times, so the person taking the measurement can accurately measure blood pressure in a comfortable position without having to worry about the position of the cuff, which is extremely convenient.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an electronic finger sphygmomanometer according to an embodiment of the present invention, and FIG. 2 is an external perspective view of an electronic sphygmomanometer according to an embodiment of the present invention.
Figure 3 (A), Figure 3 (B); 4#2 and Figure 3 (C)
FIG. 2 is a flowchart for explaining the operation of the finger electronic blood pressure monitor. 2: Finger cuff, 7: Offset selector switch. 12: MPU, 15: Light emitting element. 16: Light receiving element (for pulse wave detection). 23: Semiconductor pressure sensor 26: Pump motor, 29: Low speed exhaust valve Patent applicant: Tateishi Electric Co., Ltd. (and 1 other person) Agent: Patent attorney Shigeru Nakamura Figure 2

Claims (1)

[Claims] (1) A cuff for compressing a finger; an air pressure supply means for supplying air pressure to the cuff; an air pressure adjustment means for changing the air pressure of the cuff; a pressure sensor for detecting the pressure of the cuff; In the process of changing air pressure, a pulse wave extraction means extracts a pulse wave component of the finger artery, and blood pressure is determined based on the cuff pressure detected by the pressure sensor and pulse wave information extracted by the pulse wave extraction means. An electronic finger sphygmomanometer comprising blood pressure determination means for determining the blood pressure value, and a display device for displaying the determined blood pressure value, the cuff position input means for inputting a set height position of the cuff relative to the heart; blood pressure value correction means for calculating a correction value corresponding to the height position of the cuff input by the input means to the blood pressure value determined by the blood pressure determination means, and displaying the corrected blood pressure value as a measured value. An electronic finger blood pressure monitor characterized by displaying information on the device.