JP3700635B2 - Electronic blood pressure monitor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic sphygmomanometer, and specifically to an electronic sphygmomanometer that can detect a height difference between a measurement site and a heart.
[0002]
[Prior art]
In general, in a sphygmomanometer, an accurate blood pressure value can be obtained by measuring the blood pressure measurement site at the height of the heart. This is because when the blood pressure measurement site is lower than the heart, the blood pressure at the measurement site is high, and when it is higher than the heart, the blood pressure is low.
[0003]
Electronic blood pressure monitors for wrists and fingers are used by being worn on the wrists and fingers, but since the wrists and fingers can move freely, the wrists and fingers are set to the same height as the heart. It is difficult to measure blood pressure accurately.
[0004]
In order to avoid such a problem, Japanese Patent Application No. 2001-28334 describes a technique for detecting a height difference between a heart and a sphygmomanometer mounting portion to improve blood pressure measurement accuracy. According to this technique, the height difference between the heart and the mounting portion of the sphygmomanometer body is estimated using an angle sensor that measures the angle of the forearm and the angle of the upper arm.
[0005]
[Problems to be solved by the invention]
However, in the electronic sphygmomanometer described in Japanese Patent Application No. 2001-28334, the positional relationship between the display surface of the display unit and the angle measurement surface by the angle sensor is not uniquely determined. For this reason, for example, when an electronic sphygmomanometer is attached to the wrist, the angle measurement value varies due to the twisting of the wrist, and the estimation accuracy of the height difference between the heart and the sphygmomanometer attachment part deteriorates. It was. The problem will be described below.
[0006]
In Japanese Patent Application No. 2001-28334, the vertical angle φ _b of the forearm and the roll direction angle θ of the wrist are measured in order to detect the height difference between the heart and the measurement site. The roll direction angle θ is measured as a combined angle of the body inclination angle θ _c and the forearm longitudinal angle θ _b .
[0007]
On the other hand, as shown in FIG. 14 and FIG. 15, when the sphygmomanometer 110 is worn, the wrist is twisted so that the display surface is perpendicular to the line of sight, and the sphygmomanometer 110 is worn. The position will be changed. However, if the wrist is twisted, the sphygmomanometer main body 101 is inclined by θ _d with respect to the horizontal plane as shown in FIGS. 16 and 17.
[0008]
Here, since the angle sensor built in the sphygmomanometer body 101 normally measures the angle using gravity, it measures θ _b + θ _c + θ _d as the wrist roll direction angle θ. Yes. However, in the calculation formula for detecting the difference in elevation between the heart and the measurement site, θ = θ _b + θ _c is used assuming that the sphygmomanometer body 101 is disposed horizontally. For this reason, when the wrist is twisted as described above, the value of θ _d varies and the wrist roll direction angle θ is erroneously recognized. As a result, in the two states shown in FIGS. 16 and 17, even if the height difference between the heart and the measurement site is the same, the difference in the wrist twist angle θ _d is different, so that the height difference between the heart and the measurement site is detected. The result will be different. This becomes a detection error and leads to deterioration of blood pressure measurement accuracy.
[0009]
Therefore, an object of the present invention is to provide an electronic sphygmomanometer that can accurately measure the height difference between the heart and the measurement site by preventing variations in detection angle due to wrist twisting.
[0010]
[Means for Solving the Problems]
An electronic sphygmomanometer according to the present invention is an electronic sphygmomanometer that is attached to a predetermined part of a living body and measures the blood pressure of the predetermined part, and includes a main body and a biaxial angle measurement sensor. The main body has a display for displaying blood pressure measurement values. The biaxial angle measurement sensor is disposed in the main body or the display unit and can measure at least biaxial angles. The angle formed between the display surface of the display unit and the mounting surface of the biaxial angle measurement sensor is fixed at a predetermined angle when measuring blood pressure.
[0011]
According to the electronic sphygmomanometer of the present invention, the angle between the display surface and the sensor mounting surface is fixed when measuring blood pressure. For this reason, if the display surface of the blood pressure value is perpendicular to the line of sight, the angle θ _d formed by the sensor mounting surface and the horizontal plane is fixed. Therefore, if the angle θ _d is given to the sphygmomanometer body in advance as a default value, the wrist roll direction angle can be accurately calculated. Thereby, the height difference between the heart and the measurement site can be measured with high accuracy, and the blood pressure value can be accurately measured.
[0012]
Preferably, the electronic sphygmomanometer includes a display angle adjustment mechanism that rotatably supports the display surface with respect to the main body and adjusts the angle of the display surface with respect to the main body.
[0013]
Thereby, the torsion angle of the wrist when the measurer looks at the display unit can be reduced, and the height difference detection accuracy between the heart and the measurement site is further improved.
[0014]
In the above electronic blood pressure monitor, preferably, the display angle adjustment mechanism has a lock mechanism for fixing an angle formed by the display surface of the display unit and the mounting surface of the biaxial angle measurement sensor to a predetermined angle.
[0015]
Thereby, the angle with respect to the main-body part of the display part which is a movable part is fixable.
[0016]
In the above electronic sphygmomanometer, preferably, the display surface and the mounting surface of the biaxial angle measurement sensor are always parallel.
[0017]
Accordingly, even when the display unit is movable with respect to the main body unit, the display surface and the sensor mounting surface can be fixed without providing a lock mechanism.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0019]
(Embodiment 1)
FIG. 1 is a perspective view schematically showing a configuration of the electronic blood pressure monitor according to Embodiment 1 of the present invention. 2 and 3 are a block diagram of the electronic blood pressure monitor of FIG. 1 and a schematic cross-sectional view showing the inside of the main body.
[0020]
Referring mainly to FIG. 1, an electronic sphygmomanometer 10 includes a main body 1 in which a blood pressure measurement control device is incorporated, and a cuff 6 for attaching the main body 1 to the wrist. A display unit 4 and an operation input unit 5 are provided on the outer surface of the main body unit 1. The display unit 4 is a part mainly showing the measurement result of the blood pressure measurement, and the operation input unit 5 is a part including operation keys such as a pressure key.
[0021]
The cuff 6 includes an air bag 7 that compresses the wrist artery by storing air therein, a band-like band 8 for mounting on the wrist, and a hook-and-loop fastener 9 for winding and fixing the band 8 around the wrist. It has.
[0022]
Referring to FIGS. 2 and 3, the main body 1 includes a biaxial angle sensor 2, a substrate 3, a pressurizing pump 21, an exhaust unit 22, a pressure sensor 23, and an A / D converter. 24, an MPU (Micro Processor Unit) 25, a storage unit 26, and a buzzer 27 are provided.
[0023]
The biaxial angle sensor 2 measures two angles, ie, the vertical angle of the forearm and the roll direction angle of the wrist, and measures the angle using, for example, an acceleration sensor that measures the angle using gravity. Is. The biaxial angle sensor 2 is mounted on the surface of the substrate 3.
[0024]
The pressurizing pump 21 sends air into the air bag 7 of the cuff 6 to pressurize it, and the exhaust unit 22 exhausts the air in the air bag 7 of the cuff 6. The air pressure in the air bag 7 is detected by the pressure sensor 23, and the detection result of the pressure sensor 23 and the angle detected by the biaxial angle sensor 2 are converted into a digital signal by the A / D converter 24 and then sent to the MPU 25. Entered. The MPU 25 executes processing for blood pressure measurement by a built-in program based on various input information. Calculation data, measurement results, and the like obtained by the processing of the MPU 25 are stored in the storage unit 26, and the result is notified by the buzzer 27 depending on the result of the processing by the MPU 25. The blood pressure value obtained as a result of the processing is displayed on the display unit 4.
[0025]
With particular reference to FIG. 3, in electronic blood pressure monitor 10 of the present embodiment, a display surface of display unit 4 and a surface on which biaxial angle sensor 2 is mounted (hereinafter referred to as a “sensor mounting surface”) are notable. ) Is fixed. The display surface and the sensor mounting surface are disposed so as to be parallel to each other, for example.
[0026]
Next, the processing operation of the electronic blood pressure monitor according to the present embodiment will be described.
FIG. 4 is a schematic cross-sectional view showing a state in which the electronic sphygmomanometer in Embodiment 1 of the present invention is wound around the wrist, and FIG. 5 is a flowchart showing the processing operation of the electronic sphygmomanometer in Embodiment 1 of the present invention. It is.
[0027]
Referring to FIGS. 4 and 5, first, electronic blood pressure monitor 10 is wound around and fixed to the wrist. In this state, when the electronic sphygmomanometer 10 is turned on and starts operating, the LCD (display) is fully lit (step ST1), and then the LCD is completely turned off (step ST2), so that the display function can be confirmed. After setting, the zero setting, that is, the initial reset is completed (step ST3).
[0028]
Next, it is determined whether or not the angle detected by the biaxial angle sensor 2 that is a forearm angle detector is within a predetermined range (step ST4). If the forearm angle is not within the predetermined range, Guidance notification for the angle of the forearm to be within a predetermined range, for example, “Please raise the blood pressure monitor body slightly” is displayed (step ST5). When the angle of the forearm is within the predetermined range or enters, the pressurizing pump is turned on and the above blood pressure measurement is started (step ST6).
[0029]
The blood pressure is measured by pressurizing the inside of the air bag 7 with the pressurizing pump 21 and compressing the artery of the wrist, and then evacuating the inside of the air bag 7 with the exhaust unit 22, and the pressure inside the air bag 7 is measured with the pressure sensor 23. This is done by measuring. Thereby, the measurement of the maximum blood pressure, the minimum blood pressure, and the pulse rate is completed (step ST7). The measurement result is displayed on the display unit (step ST8), and the operation ends.
[0030]
Moreover, it is not limited to said process, The following processes may be performed.
FIG. 6 is a flowchart showing another processing operation of the electronic blood pressure monitor according to Embodiment 1 of the present invention. The hardware configuration of the circuit unit of the electronic blood pressure monitor that performs this processing operation is the same as that shown in FIGS.
[0031]
Referring to FIGS. 4 and 6, first, electronic blood pressure monitor 10 is wound around and fixed to the wrist. In this state, when the power is turned on and the operation is started, the LCD (display) is fully lit (step ST11), then the LCD is completely turned off (step ST12), and zero setting, that is, initial reset is completed (step ST12). Step ST13).
[0032]
Next, the angle of the forearm is detected by the biaxial angle sensor 2 which is a forearm angle detector (step ST14). The angle of the forearm detected here is the vertical angle of the forearm and the roll direction angle of the wrist. A height difference between the heart and the cuff is predicted from the detected angle of the forearm (step ST15). Next, the corresponding pressure correction value is converted from the predicted height difference between the heart and the cuff (step ST16), and this correction value is stored in the memory. The pressurization pump is turned on, pressurization of the air bladder 7 is started, and measurement is performed (step ST17).
[0033]
This measurement is performed by increasing the cuff pressure to the target pressure value, stopping the pressurization, and detecting the pressure pulse wave in the cuff pressure in the subsequent depressurization process. This is done by determining the systolic blood pressure value and the diastolic blood pressure value from the wave amplitude sequence data by the vibration method. When the blood pressure measurement is completed (step ST18), the measurement (determination) result is then corrected (step ST19). The correction of the blood pressure value is performed by calculating and correcting the blood pressure value determined based on the pressure correction data stored in the memory. As a measurement result, the corrected blood pressure value is displayed on the display unit (step ST20), and the operation ends.
[0034]
In the above processing operation, before measuring the angle of the forearm in step ST14, biological information such as the forearm length of the measurer is input from the operation input unit 5, and when the correction value is converted in step ST16, Correction may be performed in consideration of individual differences such as the forearm length. This correction of individual differences by inputting the forearm length in advance can also be applied to the processing operation shown in FIG.
[0035]
Next, a method for calculating the height difference between the cuff and the heart in the present embodiment will be specifically described.
[0036]
7 and 8 are views showing the inclinations of the upper arm and the forearm when the human body is viewed from the front and the side. 7 and 8, the angle of the upper arm in the left-right direction (X-axis direction) is φ _a , the angle of the upper arm in the front-rear direction (Y-axis direction) is θ _a , and the forearm in the vertical direction (Z-axis direction) The angle is φ _b , the forearm longitudinal angle is θ _b , the body leaning angle is θ _c , the forearm length is L1, the upper arm length is L2, the height from the shoulder to the heart is H, the height from the shoulder to the cuff Is Z and the twist angle of the wrist is θ _d (FIGS. 16 and 17), the height difference ΔH between the cuff and the heart is expressed by the following equation.
[0037]
ΔH = Z−H = L2 × cosφ _a × cos (θ _a + θ _c ) −L1 × sinφ _b × cos (θ _b + θ _c + θ _d ) −H
FIG. 9 is a diagram showing angles in a state where the wrist is not twisted, and FIG. 10 is a diagram showing angles in a state where the wrist is twisted.
[0038]
Referring to FIG. 9, when an acceleration sensor using gravity is used as the angle sensor, the angle sensor measures the wrist roll direction angle θ with reference to a direction perpendicular to the sensor mounting surface. In a state where the wrist is not twisted, the direction perpendicular to the sensor mounting surface and the vertical direction coincide with each other, and thus the wrist roll direction angle θ is measured as θ _b + θ _c .
[0039]
On the other hand, when the wrist is twisted as shown in FIG. 10, the direction perpendicular to the sensor mounting surface tilts the wrist twist angle by θ _d with respect to the vertical direction. In this state, when the wrist roll direction angle θ is measured with reference to the direction perpendicular to the sensor mounting surface, the wrist roll direction angle θ is measured as θ _b + θ _c + θ _d .
[0040]
Here, in the electronic sphygmomanometer described in Japanese Patent Application No. 2001-28334, the height difference ΔH between the cuff and the heart is calculated with the wrist roll direction angle θ as θ _b + θ _c as described above. Further, the positional relationship between the display surface and the sensor mounting surface has not been uniquely determined. For this reason, when the wrist is twisted, the wrist twist angle θ _d varies, and as a result, the value of ΔH varies.
[0041]
On the other hand, in the electronic sphygmomanometer according to the present embodiment, the angle formed between the display surface and the sensor mounting surface is fixed at a predetermined angle θ _d (uniquely determined). For this reason, if the display surface of the blood pressure value is perpendicular to the line of sight, the angle θ _d formed by the sensor mounting surface and the horizontal direction is fixed. Therefore, it is possible to accurately measure ΔH by previously storing the wrist twist angle θ _d in the storage unit 26 as a predetermined value.
[0042]
In the present embodiment, in the above formula, φ _a , L 1, L 2, and H are input as default values or stored in the storage unit 26, and the value of θ _a + θ _c is θ _b + θ _c + θ. _It is assumed that the value is the same as the value of _d , and ΔH is measured.
[0043]
Each angle of the upper arm may be measured with the same value as θ _b + θ _c + θ _d as described above, but may be actually measured by an angle sensor. When measuring each angle of the upper arm, the angle sensor for measuring each angle of the upper arm may be provided in the main body 1 together with the biaxial angle sensor 2, or provided separately from the main body 1. May be. Further, the above φ _a , L1, L2, and H may also be actually measured by some method.
[0044]
(Embodiment 2)
FIG. 11 is a cross-sectional view schematically showing a configuration of the electronic sphygmomanometer according to the second embodiment of the present invention. Referring to FIG. 11, the configuration of the present embodiment is different from the configuration of the first embodiment in that display unit 4 is rotatably supported by rotation mechanism 11 with respect to body unit 1. . The display unit 4 can be locked to the main body unit 1 by a lock mechanism at a predetermined angle α.
[0045]
Since the configuration other than this is substantially the same as that of the first embodiment described above, the same members are denoted by the same reference numerals, and the description thereof is omitted.
[0046]
The processing operation of the electronic sphygmomanometer in the present embodiment is the same as that in the first embodiment.
[0047]
In the present embodiment, since the display unit 4 can be rotated with respect to the main body unit 1 and can be fixed at a predetermined angle by a lock mechanism, variation in the angle at which the wrist is twisted to view the display is reduced. As a result, the level difference detection accuracy between the heart and the measurement site is further improved.
[0048]
Further, the power supply is turned on when the angle α formed by the display unit 4 is reached, and the power supply is turned off by being released from the angle α, so that a power switch is unnecessary.
[0049]
(Embodiment 3)
FIG. 12 is a cross-sectional view schematically showing a configuration of the electronic blood pressure monitor according to Embodiment 3 of the present invention. Referring to FIG. 12, the configuration of the present embodiment is compared with the configuration of the second embodiment for mounting the biaxial angle sensor 2 that is a forearm angle detector and the biaxial angle sensor 2. The substrate 3 is different in that it is provided in the display unit 4.
[0050]
In addition, since it is as substantially the same as the structure of Embodiment 2 mentioned above about the structure other than this, the same code | symbol is attached | subjected about the same member and the description is abbreviate | omitted.
[0051]
The processing operation of the electronic sphygmomanometer in the present embodiment is the same as that in the first embodiment.
[0052]
In the present embodiment, since the biaxial angle sensor 2 is disposed in the display unit 4, the angle formed between the display surface and the sensor mounting surface is always fixed. Specifically, the display surface and the sensor mounting surface are always parallel. Thereby, in order for the measurer to see the display, the variation in the angle of twisting the wrist is reduced, and the height difference detection accuracy between the heart and the measurement site is improved.
[0053]
(Embodiment 4)
This embodiment specifically shows the configuration of the lock mechanism in the fourth embodiment shown in FIG.
[0054]
FIGS. 13A to 13C are schematic diagrams showing the configuration and operation of the lock mechanism of the electronic blood pressure monitor according to Embodiment 4 of the present invention. Referring to FIG. 13A, a protrusion 4a is provided on the movable part side of the rotation mechanism 11, and guide grooves 11a and 11b for guiding the protrusion 4a are provided on the fixed part side. ing. The depth of the groove between the guide groove 11a and the guide groove 11b is shallower than the depth of the guide grooves 11a and 11b.
[0055]
Thereby, between the movable part closed state (FIG. 13A) and the movable part non-fixed state (FIG. 13B), the protrusion 4a can be easily moved along the guide groove 11a by the rotation of the display part 4. Rotate and move. However, between the movable part non-fixed state (FIG. 13 (b)) and the movable part fixed state (FIG. 13 (c)), the protrusion 4a has to get over the shallow guide groove portion. For this reason, when the protrusion 4a fits into the guide groove 11b, the movable portion of the display unit 4 is locked at that position and cannot easily move toward the guide groove 11a. With such a structure, the movable part can be fixed at a predetermined angle with respect to the fixed part.
[0056]
In the first to fourth embodiments described above, the type in which the sphygmomanometer is attached to the wrist has been described. However, the electronic sphygmomanometer of the present invention is not limited to this, and the sphygmomanometer is attached to a predetermined part of a living body. What is necessary is just to measure the blood pressure monitor of a part.
[0057]
Moreover, although Embodiment 2-4 demonstrated what the display part 4 was rotatably supported with respect to the main-body part 1, the electronic sphygmomanometer of this invention is not limited to this, As long as the display unit 4 is movable and the angle of the display unit 4 can be fixed with respect to the main body unit.
[0058]
In the first to fourth embodiments, the case where a biaxial angle sensor is used as the sensor 2 mounted on the sphygmomanometer 10 has been described. However, the sensor 2 can measure at least a biaxial angle. It may be possible to measure other angles and characteristics. The sensor 2 is not limited to an acceleration sensor, and any sensor that can measure an angle using gravity is acceptable.
[0059]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[0060]
【The invention's effect】
As described above, according to the electronic sphygmomanometer of the present invention, the angle formed between the display surface and the sensor mounting surface is fixed when measuring blood pressure. For this reason, if the display surface of the blood pressure value is perpendicular to the line of sight, the angle θ _d formed by the sensor mounting surface and the horizontal plane is fixed. Thus, if applied to a blood pressure monitor main body to predetermine the angle theta _d as an initial value, the roll direction angle of the wrist can be accurately calculated. Thereby, the height difference between the heart and the measurement site can be measured with high accuracy, and the blood pressure value can be accurately measured.
[Brief description of the drawings]
FIG. 1 is a perspective view schematically showing a configuration of an electronic sphygmomanometer according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration of an electronic blood pressure monitor according to Embodiment 1 of the present invention.
FIG. 3 is a schematic cross-sectional view showing a configuration within a main body portion of the electronic blood pressure monitor according to Embodiment 1 of the present invention.
FIG. 4 is a schematic cross-sectional view showing a state in which the electronic blood pressure monitor according to Embodiment 1 of the present invention is wound around the wrist.
FIG. 5 is a flowchart for explaining a processing operation of the electronic sphygmomanometer according to the first embodiment of the present invention.
FIG. 6 is a flowchart for explaining another processing operation of the electronic sphygmomanometer according to the first embodiment of the present invention.
FIG. 7 is a front view of a human body for explaining inclinations of an upper arm and a forearm.
FIG. 8 is a side view of a human body for explaining inclinations of an upper arm and a forearm.
FIG. 9 is a diagram showing angles in a state where there is no twist of the wrist.
FIG. 10 is a diagram showing angles in a state where the wrist is twisted.
FIG. 11 is a cross sectional view schematically showing a configuration of an electronic blood pressure monitor according to Embodiment 2 of the present invention.
FIG. 12 is a cross sectional view schematically showing a configuration of an electronic blood pressure monitor according to Embodiment 3 of the present invention.
FIG. 13 is a schematic diagram showing the configuration and operation of an electronic sphygmomanometer according to Embodiment 4 of the present invention.
FIG. 14 is a first diagram for explaining wrist twist when a conventional electronic blood pressure monitor is used.
FIG. 15 is a second view for explaining wrist twist when a conventional electronic blood pressure monitor is used.
FIG. 16 is a first view showing a state in which a conventional electronic sphygmomanometer is tilted with respect to the horizon due to twisting of the wrist.
FIG. 17 is a second view showing a state in which a conventional electronic sphygmomanometer is tilted with respect to a horizon due to wrist twisting.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main body part, 2 2-axis angle sensor, 3 board | substrate, 4 display part, 4a protrusion part, 5 operation input part, 6 cuff, 7 air bag, 8 band, 9 surface fastener, 10 electronic sphygmomanometer, 11 rotation mechanism part, 11a, 11b Guide groove, 21 Pressure pump, 22 Exhaust part, 23 Pressure sensor, 24 A / D converter, 25 MPU, 26 Storage part, 27 Buzzer.

Claims (4)

An electronic sphygmomanometer that is mounted on a predetermined part of a living body and measures the blood pressure of the predetermined part,
A main body having a display for displaying a measured value of blood pressure;
A biaxial angle measuring sensor disposed in the main body or the display and capable of measuring at least two biaxial angles;
An electronic sphygmomanometer, wherein an angle formed between a display surface of the display unit and a mounting surface of the biaxial angle measurement sensor is fixed at a predetermined angle when blood pressure is measured. The electronic sphygmomanometer according to claim 1, further comprising a display angle adjusting mechanism that rotatably supports the display surface with respect to the main body and adjusts an angle of the display surface with respect to the main body. . The display angle adjustment mechanism includes a lock mechanism for fixing an angle formed by a display surface of the display unit and a mounting surface of the biaxial angle measurement sensor to a predetermined angle. Item 3. The electronic blood pressure monitor according to Item 2. The electronic sphygmomanometer according to claim 1, wherein the display surface and the mounting surface of the biaxial angle measurement sensor are always parallel.

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