JP2001008909A - Electric sphygmomanometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric sphygmomanometer which can securely obtaine a photoelectric pulse wave signal even from an artery which is existed at a deep position from a surface of a body and select the most suitable sensor for sphygmomanometry regardless of a property of a people to be measured and precisely measure blood pressure. SOLUTION: There are provided photoelectric sensors for detecting plural pulse wave components 10-1 to 10-n and an acceleration sensor 11 for detecting physical movement on a cuff 1. The photoelectric sensor for detecting the pulse wave component of a position where is the most suitable for a property of a people to be measured is selected among the pulse wave component which is obtained by the photoelectric sensors 10-1 to 10-n and the physical movement component which is obtained by the acceleration sensor 11. Thereby, blood pressure is calculated by using the pule wave component which is obtained by the selected photoelectric sensor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic sphygmomanometer which is hardly affected by noise and artistic factors caused by body movement.

[0002]

2. Description of the Related Art Conventionally, there is a finger-type blood pressure monitor as a blood pressure monitor using a photoelectric pulse wave. Conventional sphygmomanometers such as the finger sphygmomanometer are configured as a system in which the artery of the finger pressed by the cuff is at a shallow part from the body surface, and the pulsation is measured to determine the blood pressure. Therefore, i) the distance between the light emitting element and the light receiving element is short. ii) Body motion noise is superimposed on the photoelectric pulse wave signal due to the body motion during measurement. Therefore, there are the following problems. At a site where the artery is deep from the body surface (for example, at the upper arm), it is difficult to measure the pulse wave, and it is difficult to measure the blood pressure using the photoelectric pulse wave method. In measurement during body movement, measurement errors frequently occur and measurement accuracy deteriorates.

[0003] In order to solve these problems, the applicant of the present invention has: a) a wavelength (700 to 1000) having a small attenuation rate in a living body;
nm) is used as measurement light. b) The distance between the light emitting element and the light receiving element is set within a predetermined range (2
(0 to 90 mm). c) A plurality of sensors are used for detecting a photoelectric pulse wave. We have developed a sphygmomanometer that is capable of obtaining a photoplethysmographic signal even from the pulsation of an artery located deep from the body surface.

[0004]

In the latter sphygmomanometer, which of the photoelectric pulse wave signals obtained by a plurality of sensors is most suitable for calculating the blood pressure is determined by the attribute of the subject. (For example, the circumference of the measurement site, the depth of the artery, the thickness of subcutaneous fat, etc.), it is necessary to select an appropriate sensor for each subject. However, since the attribute of the subject is not information that can be easily known by the subject, if the sphygmomanometer cannot select an appropriate sensor, a blood pressure value with insufficient accuracy is calculated as a result. .

Accordingly, the present invention has been made in view of such a problem, and it is necessary to reliably obtain a photoelectric pulse wave signal from an artery located deep from the body surface, and to improve the characteristics of the subject. It is an object of the present invention to select an optimal sensor for blood pressure measurement and to provide an electronic sphygmomanometer that realizes highly accurate blood pressure measurement by using them.

[0006]

In order to achieve the above object, an electronic sphygmomanometer according to claim 1 of the present invention provides a cuff for pressurizing a measurement site of a living body and pressurizing and depressurizing the inside of the cuff. Pressure control means, pressure detection means for detecting the pressure in the cuff, a plurality of photoelectric sensors for detecting pulse wave components provided at different positions of the cuff, and a body movement component provided on the cuff for detecting a body movement component At least one body movement component detection unit, a blood pressure calculation unit that removes a body movement component obtained by the body movement component detection unit from a pulse wave component obtained by the photoelectric sensor, and calculates a blood pressure; And a photoelectric sensor selecting unit that selects a photoelectric sensor located at a position that is optimal for the attribute of the person to be measured, and measures the blood pressure using a pulse wave component obtained by the photoelectric sensor selected by the photoelectric sensor selecting unit. It was calculated The features.

This electronic sphygmomanometer uses a body motion component (noise component) detected by the body motion component detection means to extract only a noise component from a pulse wave signal of a photoelectric sensor for detecting a pulse wave component on which a noise component is superimposed. It is to reduce. At that time, in order to accurately calculate the blood pressure, a method of directly capturing the pulse of the artery (for example, a photoelectric pulse wave) is used for detecting the pulse wave. This method can directly capture the pulsation of the artery in the central part of the cuff, which is not affected by the distribution of the cuff pressure, and shows characteristic changes in systolic and diastolic blood pressures, similar to Korotkoff sounds. Blood pressure measurement becomes possible.

However, it is difficult to measure a pulse wave at a site where the artery is deep from the body surface (for example, the upper arm) as described above. Therefore, by providing a plurality of photoelectric sensors for detecting pulse wave components at different positions of the cuff, preferably, the distance between the light emitting element and the light receiving element of the photoelectric sensor is set to be 20 to 90 mm. By using light having a wavelength (700 to 1000 nm) having a small attenuation rate in a living body as pulse wave measurement light, it is possible to capture the pulsation of an artery deep from the body surface as a photoelectric pulse wave. Become.

The reason why a plurality of photoelectric sensors are provided at different positions of the cuff is that the optimal position of the photoelectric sensor for calculating the blood pressure varies depending on the attributes of the subject. Here, the attributes of the subject are the circumference of the measurement site, the depth of the artery from the body surface, the thickness of the subcutaneous fat, and the like. In the electronic sphygmomanometer of the present invention, the photoelectric sensor at the optimal position for blood pressure calculation is selected by the photoelectric sensor selecting means from among the plurality of photoelectric sensors for detecting the pulse wave component, and the photoelectric sensor is obtained by the selected photoelectric sensor. Since the blood pressure is calculated using the obtained pulse wave component, the above problem can be solved. In other words, a photoplethysmographic signal can be reliably obtained even from an artery located deep from the body surface, and an optimal sensor for blood pressure measurement can be selected regardless of the attributes of the subject, so that highly accurate blood pressure measurement is performed. be able to.

In the present invention, when the body movement component detecting means is a sensor for converting the movement of a living body into a physical quantity for measurement, a speed sensor, an acceleration sensor, a position sensor,
In the case of a displacement sensor, an angle sensor, a direction sensor, an inclination sensor, or the like, a sensor that measures a biomass (for example, a blood volume) that changes according to the movement of a living body may use a photoelectric sensor or the like.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. FIG. 1 is a block diagram showing the configuration of the electronic sphygmomanometer according to the first embodiment. This electronic sphygmomanometer includes a cuff 1 for pressurizing a measurement site of a living body, a pressure pump (pressure control means) 2 for pressurizing the inside of the cuff 1, and an exhaust valve (pressure control means) 3 for reducing the pressure in the cuff 1 And a pressure sensor (pressure detecting means) 4 for detecting the pressure in the cuff 1, a display 5 for displaying the calculated blood pressure value and the like, a pressurizing pump 2, an exhaust valve 3, a display 5 and the like. A CPU 6, an amplifier 7 for amplifying an output from the pressure sensor 4, and an A for converting an analog signal from the amplifier 7 into a digital signal and inputting the digital signal to the CPU 6.
/ D converter 8. However, the configuration so far is the same as that of a conventional sphygmomanometer.

This electronic sphygmomanometer includes photoelectric sensors 10 _-1 ,..., 10 _-n for detecting a plurality of pulse wave components provided on the cuff 1.
And one acceleration sensor 11 as body movement component detection means also provided on the cuff 1.
0 _-1, ..., 10 _-n are provided at different positions of the cuff 1, CPU 6 photoelectric sensor 10 _-1, ..., body movement obtained from the pulse wave components obtained in 10 _-n in the acceleration sensor 11 A blood pressure calculating function for calculating a blood pressure by removing components, and a photoelectric sensor selection for selecting a photoelectric sensor at an optimal position for the attribute of the subject from among the plurality of photoelectric sensors 10 _-1 ,..., 10 _-n. It is characterized by having a function and calculating a blood pressure using a pulse wave component obtained by a selected photoelectric sensor.

The photoelectric sensors 10 _-1 ,..., 10 _-n are:
As described above, the distance between the light emitting element and the light receiving element is 20
It is provided so as to be in a range of up to 90 mm, and uses light of a wavelength (700 to 1000 nm) having a small attenuation rate in a living body. The photoelectric pulse wave signals of the photoelectric sensors 10 _-1 ,..., 10 _-n are respectively amplified by amplifiers 12 _-1 ,..., 12 _-n and further converted into digital signals by the A / D converter 8. Is input to Also, the acceleration sensor 1
The first body motion signal is amplified by the amplifier 13, converted into a digital signal by the A / D converter 8, and then input to the CPU 6.

The electronic sphygmomanometer according to the second embodiment shown in FIG. 2 uses one photoelectric sensor 14 instead of the acceleration sensor 11 as a body movement component detecting means. The electronic sphygmomanometer according to the third embodiment includes a plurality of photoelectric sensors 14 _-1 ,..., 14 _-n as body movement component detecting means.
Is used. Other configurations are the same as those of the electronic sphygmomanometer of the first embodiment.

An electronic sphygmomanometer according to the first embodiment (see FIG. 1)
FIG. 4 shows a schematic sectional view of the cuff 1 in FIG. FIG. 4 shows a state in which the cuff 1 is mounted on the upper arm 40, and a bone 41 and an artery 42 extend inside the upper arm 40. Here, the acceleration sensor 11 for detecting a body motion component is attached to the front side of the cuff 1,
A plurality (three) of photoelectric sensors 10 _-1 for detecting a pulse wave component,
10 _-2 and 10 _-3 are attached inside the cuff 1 (the side facing the body surface). Each of the photoelectric sensors 10 _-1 , 10 _-2 , and 10 _-3 does not include a light emitting element and a light receiving element, but the light emitting element 20 is common to all photoelectric sensors. Are for each photoelectric sensor. The light emitting element 20 and the light receiving elements 21 to 23 are arranged in the circumferential direction of the cuff 1 (the upper arm 4).
0 (in the transverse direction), and the light receiving elements 21, 22, and 23 are respectively located at different positions from the light emitting element 20. Of course, the light emitting element 20 and the light receiving elements 21 to 23 are within the predetermined range (20 to 90 m).
m).

An electronic sphygmomanometer according to a second embodiment (see FIG. 2)
5 shows a schematic sectional view of the cuff 1 in FIG. In FIG.
The photoelectric sensor 14 for detecting a body motion component is not composed of a light emitting element and a light receiving element, and the light emitting element is common to the light emitting elements 20 of the photoelectric sensors _10-1 , _10-2 , and _10-3 for detecting a pulse wave component. , Only the light receiving element 31 is disposed on the opposite side to the light receiving elements 21 to 23 with the light emitting element 20 interposed therebetween.

An electronic sphygmomanometer according to a third embodiment (see FIG. 3)
6 shows a schematic sectional view of the cuff 1 in FIG. In FIG.
Plural (three) photoelectric sensors 14 for detecting a body motion component_-1,
14 _-2, 14_-3Is similar to the case of FIG.
Photoelectric sensor 10 for detecting wave components_-1, 10_-2, 10_-3Departure
It is common to the optical element 20 and has three light receiving elements 31, 32,
33 are arranged at different positions. This place
Between the light emitting element 20 and each of the light receiving elements 31, 32, 33
Are distances between the light emitting element 20 and the light receiving elements 21 and 21, respectively.
The distance is set to be the same as the distance between 2 and 23.

In particular, in the case of FIG. 6, the photoelectric sensor 10 _-1 , 1 for detecting a pulse wave component is located at a position which is optimal for the attribute of the subject.
When 0 _-2 and 10 _-3 are selected, a plurality of (three) photoelectric sensors 14 _-1 and 14 for detecting a plurality of (3) body motion components are used to determine the fundamental frequency of the body motion component. The output of any one of _-2 and _14-3 may be used. This is because only the fundamental frequency of the body motion component is required at the time of selection.

Also, photoelectric sensors 14 _-1 for detecting body movement components,
An advantage of providing a plurality of 14 _-2 and 14 _-3 is that it is effective for removing body motion noise superimposed on a pulse wave. That is, noise removal is performed using a photoelectric sensor for detecting a body motion component corresponding to the photoelectric sensor for detecting a pulse wave component selected as being located at a position that is optimal for the attribute of the subject. More specifically, if the photoelectric sensor 10 _-1 (that is, the light receiving element 21) for detecting the pulse wave component is selected, the detection of the body motion component located at the same distance as the distance between the light emitting element 20 and the light receiving element 21 is performed. The noise is removed using the body motion signal obtained by the photoelectric sensor 14 _-1 (that is, the light receiving element 31). By obtaining both the photoelectric pulse wave signal and the body motion signal with the light receiving element located at the same distance from the light emitting element 20, the amount of change in the biomass, which is the body motion component, acts in the same manner on the photoelectric pulse wave signal and the body motion signal. Therefore, a body motion signal having a high correlation with the body motion component superimposed on the photoelectric pulse wave signal can be obtained, and the noise removal efficiency increases.

Further, in the cuff 1 shown in FIGS. 4 to 6, the photoelectric sensors for detecting the pulse wave component and the body motion component are both in a direction perpendicular to the circumferential direction of the cuff 1 (extending direction of the artery 42).
At the center or at the terminal side (hand side) of the living body 1 from the center. Therefore, the photoelectric pulse wave signal and the body motion signal can be accurately detected. This is because, even if the cuff 1 is pressurized to the highest blood pressure or higher on the heart side from the center of the cuff 1, the compression force is weaker than the central part of the cuff, so that the artery 42 is not completely occluded, This is because a pulse wave corresponding to the heartbeat may be generated.

By the way, the selection of the photoelectric sensor for detecting the pulse wave component at the position most suitable for the attribute of the subject depends on various processes depending on whether the blood pressure is measured in the depressurizing process or the pressurizing process of the cuff. Can be run with For example, in the case where the selection is performed by the decompression measurement, the operation of the electronic sphygmomanometer configured as shown in FIGS. 3 and 6 will be described with reference to the flowchart of FIG. In this case, the blood pressure measurement is performed during the decompression process.
In other words, as shown in FIG. 9, the cuff 1 is once pressurized to a pressure equal to or higher than the systolic blood pressure, a photoelectric sensor for detecting a pulse wave component is selected in the pressurizing process, and after the pressurization, the pressure is reduced at a constant pressure. As a blood pressure determination method, for example, a pulse wave appearance point in the pressure reduction process is set as a systolic blood pressure, and a pulse wave disappearance point is set as a diastolic blood pressure. As another blood pressure determining method, there is a method of calculating the envelope of the pulse wave amplitude, and setting and determining a predetermined threshold value.

First, in step (hereinafter abbreviated as ST) 1, after all variables are initialized, pressurization of the cuff is started (ST2). During this pressurization, photoelectric pulse wave signals are measured by photoelectric sensors 10 _-1 , 10 _-2 , and 10 _-3 for detecting a pulse wave component composed of the light emitting element 20 and the light receiving elements 21 to 23, and the light emitting element 20-1 and photoelectric sensors 14 _-1 , 14 _-2 , 14 _-3 for detecting body movement components, which are composed of light receiving elements 31 to 33.
, A body motion signal is measured (ST3).

Next, a photoelectric sensor for detecting a pulse wave component at a position optimal for the attribute of the subject is determined (ST).
4). As an index of the optimal photoplethysmographic signal, the photoplethysmographic signal from each photoelectric sensor is frequency-analyzed to calculate signal power, and the pulse wave component and the body motion component signal power at each signal power are compared. The photoelectric sensor having the highest component-to-body motion component ratio (hereinafter, referred to as S / N ratio) is defined as the photoelectric sensor located at a position that is optimal for the attribute of the subject. Since the high S / N ratio means that the pulse wave component is captured better than the body motion noise, the photoelectric sensor that can obtain the signal power with the highest S / N ratio is the subject. Will be suitable for the attribute. Conversely, a low S / N ratio means that
Compared with the body motion noise, it means that the pulse wave component is not sufficiently captured, so that the photoelectric sensor that can obtain only a signal power with a low S / N ratio is not suitable for the attribute of the subject, In the subsequent body motion noise removal processing, a sufficient noise removal effect cannot be expected, and accurate blood pressure calculation cannot be performed.

After the photoelectric sensor for detecting the pulse wave component at the position optimal for the attribute of the subject is determined as described above, the body motion component corresponding to the selected photoelectric sensor for detecting the pulse wave component is detected. Are determined (ST5). That is,
In FIG. 6, as a photoelectric sensor for detecting a pulse wave component at a position that is optimal for the attribute of the subject, for example, a photoelectric sensor 10
_{When -3} (light receiving element 23) is selected, the photoelectric sensor 14 _-3 (light receiving element 33) located at the same distance as the distance between the light emitting element 20 and the light receiving element 23 is determined.

When the internal pressure of the cuff reaches or exceeds the maximum blood pressure, decompression at a constant pressure is started (ST6). During the decompression process, measurement of the cuff pressure, measurement of the photoelectric pulse wave signal, and measurement of the body motion signal are performed. (ST7), a body motion component that becomes noise is removed from the photoelectric pulse wave signal based on the measurement result (ST8). A specific method for detecting a pulse wave component and a body motion component from the signal power calculated by frequency analysis of the photoelectric pulse wave signal is as follows. First, a body motion signal measured by an arbitrary photoelectric sensor among a plurality (three) of photoelectric sensors 14 _-1 , 14 _-2 , and 14 _-3 for detecting body motion components is subjected to frequency analysis. ,
Calculate the fundamental frequency of the body motion component. Subsequently, in the signal power obtained by frequency analysis of the photoelectric pulse wave signal, a component that matches the fundamental frequency of the body motion component obtained earlier becomes the signal power of the body motion component, and in the remaining signal power,
The component obtained by removing the harmonic component of the fundamental frequency of the body motion component becomes the signal power of the pulse wave component.

For example, FIGS. 11 and 12 show blood pressure measurement during body movement, FIG. 11 shows photoelectric pulse wave signals obtained by three photoelectric sensors for detecting pulse wave components, and FIG.
9 shows a body motion signal obtained by a photoelectric sensor for detecting individual body motion components. As is clear from this, in the signal power of the photoelectric pulse wave signal, a component that matches the fundamental frequency of the body motion component is the signal power of the body motion component.

After the body motion component is removed from the photoelectric pulse wave signal, the systolic blood pressure and the diastolic blood pressure are calculated (ST9), and the obtained blood pressure values are displayed (ST10). The flow chart of FIG. 7 is a case where the photoelectric sensor for detecting the pulse wave component at the position most suitable for the attribute of the subject is selected by the pressure reduction measurement. FIG. In this case, the blood pressure measurement is performed during pressurization of the cuff. As shown in FIG. 10, the selection of the photoelectric sensor for detecting the pulse wave component is performed, for example, by performing pre-pressurization before pressurization for measuring blood pressure, and in this pre-pressurization process. This is because in the pressure measurement, when the cuff pressure is lower than the diastolic blood pressure, there is a case where there is no section in which a pulse wave appears.

First, after initialization is performed in ST11, pre-pressurization of the cuff is performed (ST12), and a photoelectric pulse wave signal and a body motion signal are measured during the pre-pressurization (ST13).
Then, in the same manner as described above, the photoelectric sensor for detecting the pulse wave component at the position optimal for the attribute of the subject is determined (ST1).
4) A photoelectric sensor for detecting a body motion component is determined accordingly (ST15).

Next, the cuff is pressurized to a pressure equal to or higher than the systolic blood pressure (ST16). During the pressurization process, measurement of the cuff pressure, measurement of the photoelectric pulse wave signal, and measurement of the body motion signal are performed (ST17).
The body movement component is removed from the photoelectric pulse wave signal based on the measurement result (ST18). Thereafter, the systolic blood pressure and the diastolic blood pressure are calculated (ST19), and the obtained blood pressure values are displayed (ST19).
20), the cuff is rapidly exhausted (ST21).

The flow charts of FIGS. 7 and 8 show a case where a photoelectric sensor for detecting a pulse wave component located at a position most suitable for the attribute of the subject is measured by pressure reduction measurement and pressure measurement, respectively. However, in both the decompression measurement and the pressure measurement,
It can also be performed during blood pressure calculation (ST9 in FIG. 7, ST19 in FIG. 8). Further, the above embodiment relates to selection in blood pressure measurement during body movement, but the same applies to blood pressure measurement at rest. That is, in this case, the photoelectric sensor having the highest signal power obtained by frequency-analyzing the photoelectric pulse wave signal is the photoelectric sensor located at a position optimal for the attribute of the subject.

For example, FIGS. 13 and 14 show blood pressure measurements under resting conditions, FIG. 13 shows photoelectric pulse wave signals obtained by three photoelectric sensors for detecting pulse wave components, and FIG.
9 shows a body motion signal obtained by a photoelectric sensor for detecting individual body motion components. In this case, among the signal powers of the photoelectric pulse wave signals, the photoelectric sensor having the highest signal power (here, sensor 3) is optimal.

Further, it is possible to similarly determine whether the blood pressure measurement is being performed during body movement or whether the measurement is being performed at rest. That is, as shown in FIG. 14, the value of the signal power obtained by frequency analysis of the body motion signal measured by the photoelectric sensor for body motion component detection is compared with a preset threshold. If the signal power is greater than the threshold, it is determined that the noise is body movement noise, and if a large amount of the body movement noise is detected, it is determined that the measurement is during body movement. Conversely, when the signal power is smaller than the threshold value, it is determined that it is not body motion noise, and when no or only a small amount of body motion noise is detected, it is determined that the measurement is at rest.

In addition, the above flow chart shows a case in which a plurality of photoelectric sensors are used for detecting a body movement component (see FIG. 3). However, in the case of one acceleration sensor or photoelectric sensor (see FIGS. 1 and 2). The same applies to the above. However, in this case, it is not necessary to determine the sensor for detecting the body motion component according to the selection of the photoelectric sensor for detecting the pulse wave component.

[0034]

The electronic sphygmomanometer of the present invention has the following effects because it is configured as described above. (1) A photoplethysmographic signal can be reliably obtained from an artery located deep from the body surface. (2) An optimal photoelectric sensor for detecting a pulse wave component can be selected from among a plurality of photoelectric sensors for detecting a pulse wave component, regardless of the attributes of the subject. (3) According to (1) and (2), highly accurate blood pressure measurement can be performed. (4) According to the configuration of claim 7, a body motion signal having a high correlation with the body motion component superimposed on the photoelectric pulse wave signal can be obtained, and the noise removal efficiency increases. (5) According to the configuration of claim 16, the photoelectric pulse wave signal and the body motion signal can be accurately detected.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an electronic sphygmomanometer according to a first embodiment.

FIG. 2 is a block diagram illustrating a configuration of an electronic sphygmomanometer according to a second embodiment.

FIG. 3 is a block diagram illustrating a configuration of an electronic sphygmomanometer according to a third embodiment.

FIG. 4 is a schematic sectional view of a cuff in the electronic sphygmomanometer according to the first embodiment.

FIG. 5 is a schematic sectional view of a cuff in the electronic sphygmomanometer according to the second embodiment.

FIG. 6 is a schematic sectional view of a cuff in an electronic sphygmomanometer according to a third embodiment.

FIG. 7 is a flowchart showing an operation of the electronic sphygmomanometer according to the third embodiment in a case where blood pressure measurement is performed during the depressurization process of the cuff.

FIG. 8 is a flowchart showing the operation of the electronic sphygmomanometer according to the third embodiment in the case where blood pressure measurement is performed during the cuff pressurization process.

FIG. 9 is a graph showing the relationship between time and cuff pressure when blood pressure measurement is performed during the depressurization process of the cuff.

FIG. 10 is a graph showing the relationship between time and cuff pressure when blood pressure measurement is performed during the cuff pressurization process.

FIG. 11 is a graph showing a photoelectric pulse wave signal obtained by a photoelectric sensor for detecting a pulse wave component in the electronic sphygmomanometer according to the embodiment in the case of measuring blood pressure during body movement.

FIG. 12 is a graph showing a body motion signal obtained by a photoelectric sensor for detecting a body motion component in the electronic sphygmomanometer according to the embodiment in the case of measuring blood pressure during body movement.

FIG. 13 is a graph showing a photoelectric pulse wave signal obtained by a photoelectric sensor for detecting a pulse wave component in the electronic sphygmomanometer according to the embodiment in the case of blood pressure measurement under rest.

FIG. 14 is a graph showing a body motion signal obtained by a photoelectric sensor for detecting a body motion component in the electronic sphygmomanometer according to the embodiment in the case of measuring blood pressure under rest.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cuff 2 Pressure pump (pressure control means) 3 Exhaust valve (pressure control means) 4 Pressure sensor (pressure detection means) 6 CPU (blood pressure calculation means, photoelectric sensor selection means) _10-1 , ..., 10- _n pulse wave Photoelectric sensor for component detection 11 Acceleration sensor for body motion component detection (body motion component detection means) 14 _-1 ,..., 14- _n Photoelectric sensor for body motion component detection (body motion component detection means)

Claims (16)

[Claims] 1. A cuff for pressurizing a measurement site of a living body,
Pressure control means for pressurizing and depressurizing the inside of the cuff, pressure detecting means for detecting the pressure inside the cuff, and a plurality of pulse wave component detecting photoelectric sensors provided at different positions of the cuff,
At least one body movement component detecting means provided on the cuff and detecting a body movement component, and removing the body movement component obtained by the body movement component detection means from the pulse wave component obtained by the photoelectric sensor to reduce blood pressure A blood pressure calculating means for calculating, and a photoelectric sensor selecting means for selecting a photoelectric sensor located at a position most suitable for the attribute of the person to be measured among the plurality of photoelectric sensors, the photoelectric sensor selected by the photoelectric sensor selecting means An electronic sphygmomanometer characterized in that blood pressure is calculated using a pulse wave component obtained by the following. 2. The photoelectric sensor selecting means calculates a signal power by frequency-analyzing a photoelectric pulse wave signal obtained by a plurality of photoelectric sensors, and calculates a pulse wave component and a body motion component signal obtained by each photoelectric sensor. The photoelectric sensor having the highest ratio of pulse wave component to body motion component by comparing powers is a photoelectric sensor located at a position optimal for the attribute of the subject.
Electronic blood pressure monitor as described. 3. The photoelectric sensor selecting means calculates a signal power by frequency-analyzing a photoelectric pulse wave signal obtained by a plurality of photoelectric sensors, and frequency-analyzes a body motion component obtained by a body motion component detecting means. Calculating the fundamental frequency of the body motion component, and among the components in the signal power of the photoplethysmogram, the component in which the fundamental frequency of the body motion component matches the frequency of the signal power of the photoplethysmogram is defined as the body motion component. The electronic sphygmomanometer according to claim 2, characterized in that: 4. The electronic sphygmomanometer according to claim 1, wherein said body movement component detecting means is a sensor for converting a movement of a living body into a physical quantity and measuring the physical quantity. 5. An electronic sphygmomanometer according to claim 1, wherein said body movement component detecting means is a sensor for measuring a biomass that changes according to the movement of the living body. 6. The electronic sphygmomanometer according to claim 5, wherein the sensor for measuring the biomass is a photoelectric sensor. 7. The body movement component detecting means includes a plurality of photoelectric sensors, and the plurality of body movement component detection photoelectric sensors correspond to the plurality of pulse wave component detection photoelectric sensors. A body motion component corresponding to a pulse wave component detection photoelectric sensor that is provided at a different position of the cuff and is at a position that is optimal for the attribute of the subject among a plurality of body motion component detection photoelectric sensors. The electronic sphygmomanometer according to claim 6, wherein a body motion signal obtained by the photoelectric sensor for detection is used for removing a body motion component in blood pressure calculation. 8. The electronic sphygmomanometer according to claim 1, further comprising a discriminating means for discriminating between a blood pressure measurement at rest and a blood pressure measurement during body movement. 9. An electronic sphygmomanometer according to claim 8, wherein said discriminating means discriminates according to the magnitude of signal power obtained by frequency analysis of the body motion signal obtained by the body motion component detecting means. 10. In the case of measuring blood pressure at rest, the photoelectric sensor selecting means determines a photoelectric sensor having the largest signal power obtained by frequency analysis of a photoelectric pulse wave signal obtained by each photoelectric sensor. 2. The electronic sphygmomanometer according to claim 1, wherein the photoelectric sensor is located at a position optimal for the attribute of the electronic blood pressure sensor. 11. The method according to claim 1, wherein the calculation of the blood pressure is performed in a pressure reducing process in the cuff, and the selection of the photoelectric sensor by the photoelectric sensor selecting means is performed in a pressurizing process in the cuff. The electronic sphygmomanometer according to claim 3, claim 4, claim 5, claim 5, claim 6, claim 7, claim 8, claim 9, or claim 10. 12. The method according to claim 1, wherein the calculation of the blood pressure is performed during a pressure reduction process in the cuff, and the selection of the photoelectric sensor by the photoelectric sensor selecting means is performed in parallel with the calculation of the blood pressure. The electronic sphygmomanometer according to claim 3, claim 4, claim 5, claim 5, claim 6, claim 7, claim 8, claim 9, or claim 10. 13. The blood pressure calculation is performed during a pressurization process in a cuff, and a preliminary pressurization is performed before pressurization for calculating a blood pressure.
The selection of the photoelectric sensor by the photoelectric sensor selecting means is performed in a pre-pressurization process, wherein the selection of the photoelectric sensor is performed in a pre-pressurization process. 11. The electronic sphygmomanometer according to claim 8, claim 9, or claim 10. 14. The method according to claim 1, wherein the calculation of the blood pressure is performed during a pressurization process in the cuff, and the selection of the photoelectric sensor by the photoelectric sensor selecting means is performed in parallel with the calculation of the blood pressure. The electronic sphygmomanometer according to claim 3, claim 4, claim 5, claim 5, claim 6, claim 7, claim 8, claim 9, or claim 10. 15. The photoelectric sensor according to claim 1, wherein the photoelectric sensors are arranged at different positions in a circumferential direction of the cuff. An electronic sphygmomanometer according to claim 7, claim 8, claim 9, claim 9, claim 10, claim 11, claim 12, claim 13, or claim 14. 16. The photoelectric sensor according to claim 1, wherein the photoelectric sensor is disposed at a center in a direction perpendicular to the circumferential direction of the cuff or at a terminal side of the living body from the center. Claim 4, Claim 5, Claim 6, Claim 7, Claim 8, Claim 9, Claim 10, Claim 11, Claim 12,
The electronic sphygmomanometer according to claim 13, claim 14, or claim 15.