KR102360029B1 - Apparatus for acquiring iological information, wristwatch type terminal device, and method for acquiring iological information - Google Patents

Abstract

Disclosed are a device for acquiring biometric information, a wrist watch-type terminal, and a method for acquiring biometric information. The disclosed biometric information acquisition device includes a first detector for detecting reflected light or transmitted light from the living body by irradiating the living body with light of a first wavelength, and a second detecting unit for detecting reflected or transmitted light from the living body by irradiating the living body with light of a second wavelength. 2 a detection unit, and a processing unit for calculating a pulse wave of the living body according to a subtraction value obtained by subtracting a detection signal obtained by irradiating light of a second wavelength to the living body from a detection signal obtained by irradiating light of a first wavelength to the living body;

Description

Apparatus for acquiring iological information, wristwatch type terminal device, and method for acquiring iological information

The present disclosure relates to a device for acquiring biometric information, a wrist watch-type terminal, and a method for acquiring biometric information, and more particularly, a device for acquiring biometric information that derives a pulse wave of a living body according to a detection signal obtained by irradiating light to a living body, wrist watch type It relates to a terminal and a method for acquiring biometric information.

When light of a predetermined wavelength is irradiated to a living body, the light is scattered (reflected/transmitted) from the epidermis, dermis surface, peripheral blood vessels, fat, and arteries of the living body. The corresponding periodic movement can be observed from the reflected light obtained from the periodic movement of the pulse of the blood vessel within a certain time or the transmitted light passing through the living body. Therefore, in recent years, the pulse wave is measured by analyzing such reflected light or transmitted light.

In this regard, the following Patent Document 1 (Japanese Patent Laid-Open No. 2002-369805) discloses a wavelength shorter than that of near-infrared light from a detection signal of the amount of reflected light from a blood vessel obtained by irradiating a living body with near-infrared light in order to eliminate biological motion noise. A technique for deriving a pulse wave by subtracting a detection signal of the amount of reflected light from the skin surface obtained by irradiating a living body with the light of

Japanese Patent Laid-Open No. 2002-369805

Although the technique of Patent Document 1 above has been devised to eliminate biological motion noise, since biological motion noise accounts for only 4 to 5% of the total noise added to pulse waves, it is possible to significantly improve the accuracy of pulse wave measurement even if biological motion noise is removed. can't

An object of the present disclosure is to provide a biometric information acquisition device capable of precisely measuring a pulse wave, a wrist watch-type terminal, and a biometric information acquisition method to solve these problems.

An apparatus for obtaining biometric information according to an embodiment includes: a first detection unit configured to detect reflected light or transmitted light in the living body by irradiating light of a first wavelength to the living body; a second detection unit irradiating light of a second wavelength to the living body to detect reflected light or transmitted light in the living body; and a processing unit for deriving a pulse wave of the living body according to a subtraction value obtained by subtracting a detection signal obtained by irradiating light of a second wavelength to the living body from a detection signal obtained by irradiating light of the first wavelength to the living body.

A method for acquiring biometric information according to another embodiment includes: detecting reflected light or transmitted light in the living body by irradiating the living body with light of a first wavelength; detecting reflected light or transmitted light in the living body by irradiating light of a second wavelength to the living body; and deriving a pulse wave of the living body according to a subtraction value obtained by subtracting a detection signal obtained by irradiating light of a second wavelength to the living body from a detection signal obtained by irradiating light of the first wavelength to the living body.

A biometric information acquisition device according to another embodiment includes: a substrate; one of a light source and a receiver installed on the substrate; a plurality of other light sources or receivers installed on the substrate and arranged at least one on a double or more substantially concentric circle centered on either one of the light source and the receiver; and a processing unit that derives a pulse wave of the living body according to the detection signal of reflected light or transmitted light from the living body received by the light receiver.

According to the present disclosure, it is possible to provide a biometric information acquisition device, a wrist watch-type terminal, and a biometric information acquisition method capable of measuring a pulse wave with high precision.

1 is a block diagram schematically showing an apparatus for obtaining biometric information according to an embodiment.
2 is a plan view schematically illustrating a sensor unit of a biometric information acquisition device according to an embodiment.
3 is a diagram schematically illustrating a state in which light emitted from a light source of an apparatus for obtaining biometric information according to an embodiment is received by a light receiver through a living body.
4 is a flowchart illustrating a method for acquiring biometric information according to an embodiment.
5 is a diagram illustrating an example of emission timing of red light or infrared light and green light.
6 is a diagram showing another example of emission timing of red light or infrared light and green light.
7 is a diagram exemplarily showing a detection signal of a first detection unit input to a processing device.
8A and 8B are diagrams illustrating a waveform of a subtraction value obtained by subtracting a detection signal of a second detection unit from a detection signal of a first detection unit, and an example of a feature point extracted from the subtraction value and the subtraction value.
9B and 9B are diagrams for calculating the blood pressure of a living body according to extracted feature points and a regression line.
10 is a diagram schematically showing a sensor unit according to another embodiment.
11 is a diagram schematically showing a sensor unit according to still another embodiment.
12 is a diagram schematically showing a sensor unit according to still another embodiment.
13 is a diagram schematically showing a sensor unit according to still another embodiment.
14 is a diagram schematically showing a sensor unit according to another embodiment.
Fig. 15 is a diagram schematically showing a sensor unit having a configuration capable of detecting the contact pressure of the first light source to the living body.
Fig. 16 is a diagram schematically showing a configuration in which the contact pressure of the first light source to the living body can be adjusted to a preset value.
17 is a diagram schematically showing a wrist watch-type terminal according to another embodiment.
FIG. 18 shows a rear view of the wrist watch-type terminal of FIG. 17 .

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following examples of the present invention are only intended to embody the present invention and do not limit or limit the scope of the present invention. In addition, what a person of ordinary skill in the art can easily infer from the detailed description and embodiments of the present invention is construed as belonging to the scope of the present invention.

First, a biometric information acquisition device and a biometric information acquisition method of the present embodiment will be schematically described. The biometric information acquisition device and biometric information acquisition method of the present embodiment apply light of the second wavelength to the living body from a detection signal (ie, output waveform) of reflected light or transmitted light from a blood vessel obtained by irradiating light of a first wavelength to a living body. The pulse wave of the living body is obtained according to the subtraction value obtained by reducing the detection signal of reflected light or transmitted light in the vicinity of the large dermis as noise obtained by irradiation. In this way, a detection signal with little noise can be obtained, and the pulse wave of the living body and, consequently, the blood pressure of the living body can be measured at an improved level.

<First embodiment>

First, the biometric information acquisition device of this embodiment will be described in detail. Fig. 1 is a block diagram schematically showing a biometric information acquisition device of the present embodiment. Fig. 2 is a plan view schematically showing a sensor unit in the biometric information acquisition device of the present embodiment. Fig. 3 is a diagram schematically showing a state in which light emitted from a light source is received by a light receiver through a living body in the biometric information acquisition device of the present embodiment.

The biometric information acquisition device 1 is, for example, a biometric information acquisition device installed in a wearable terminal, and is mounted on a wrist or the like. The biometric information acquisition device 1 includes a sensor unit 10 , an analog front end (AFE) 20 , a processing device 30 , and a display unit 40 , as shown in FIG. 1 .

The sensor unit 10 includes a first detection unit 11 and a second detection unit 12 , and operates according to a control signal from the processing device 30 . The first detection unit 11 includes a light source that emits red light (for example, wavelength 620 nm or more and 780 nm or less) or infrared light (IR: for example, wavelength 780 nm or more and 1100 nm or less) as detection light, and the detection light and a light receiver for receiving the light reflected or transmitted in the living body.

The second detection unit 12 includes a light source that emits green light (for example, a wavelength of 495 nm or more and 570 nm or less) as detection light, and a light receiver that receives the light reflected or transmitted from the detection light in the living body. do.

As a light source of the 1st detection part 11 and the 2nd detection part 12, light emitting elements, such as LED (Light Emitting Diode) and LD (Laser Diode), are employable, for example. As the light receivers of the first detection unit 11 and the second detection unit 12, a light receiving element such as a CCD (Charge Coupled Device) or a CMOS image sensor (Complementary Metal Oxide Semiconductor Image Sensor) can be used. The light receiver photoelectrically converts the received light and outputs a signal indicating the intensity of the received light to the AFE 20 .

The sensor unit 10 of this embodiment irradiates a living body with red light or infrared light through the first detection unit 11 to receive reflected light reflected from a blood vessel located deeper than the dermis, and emits green light through the second detection unit 12 . It irradiates a living body and receives reflected light reflected from peripheral blood vessels or fat near the dermis.

In detail, the sensor unit 10 includes a first light source 111 that emits red light or infrared light as detection light and a second light source 111 that emits green light as detection light on the common substrate 13 as shown in FIG. 2 . It includes a light source 121 , a third light source 122 emitting green light as detection light, and a light receiver 112 . In other words, the sensor unit 10 of this embodiment is provided with one first detection unit 11 and two second detection units 12 , and as a light receiver of the two second detection units 12 , the first detection unit 11 . of the light receiver 112 is used in common. With such a configuration, the number of light receivers 112 can be reduced, so that the sensor unit 10 can be downsized.

Here, in general, the distance between the light receiver and the light source corresponds to the degree to which the light reaches deeply into the living body. In the present embodiment, as shown in FIG. 3 , the third light source 122 , the second light source 121 , and the first light source 111 are arranged in the order away from the light receiver 112 . In other words, the first light source 111 used to obtain the reflected light of blood vessels existing inside the living body rather than the dermis is disposed at a position further away from the light receiver 112 than the second light source 121 and the third light source 122, have. With such an arrangement, the reflected light from the blood vessel can be received favorably. In addition, in FIG. 3, the irradiation area of light is shown by hatching part. In addition, the interval between the first light source 111 , the second light source 121 , and the third light source 122 may be appropriately set based on the wavelength of the emitted light or the like.

On the other hand, the first light source 111 , the second light source 121 , and the third light source 122 of the present embodiment are arranged on a straight line at approximately equal intervals as shown in FIG. 2 . In the present specification, the term "straight line" includes not only a straight line in a strict sense, but also a case that can be regarded as an approximate straight line from the point of view of those skilled in the art. With such an arrangement, when the biometric information acquisition device 1 is mounted on a living body, the first light source 111 , the second light source 121 , and the third light source 122 can be arranged on substantially the same blood vessel. can improve the measurement accuracy of

The AFE 20 includes an amplifier 21 , a noise removal filter 22 , and an Analog Digital Converter (ADC) 23 . The amplifier 21 amplifies the detection signal from the sensor unit 10 . The noise removal filter 22 is an analog filter, and removes the noise of the detection signal amplified by the amplifier 21 by analog processing. For example, the noise removal filter 22 may be an LC filter such as a low-pass filter or a high-pass filter.

The ADC 23 converts the detection signal from which the noise has been removed by the noise removal filter 22 into a digital signal. Then, the ADC 23 outputs the detection signal converted into the digital signal to the processing device 30 . The ADC 23 outputs a digital value sampled at a predetermined sampling period as a detection signal.

The processing device 30 is, for example, a microcomputer, and includes a CPU (Central Processing Unit) 31 , a memory 32 , a digital filter 33 , and a power management unit 34 . The memory 32 stores a predetermined program. The CPU 31 reads out the program stored in the memory 32 and executes it. Based on the detection signal from the AFE 20 , the processing device 30 measures blood pressure (SBP, DBP) and the like, and outputs a signal indicating the measured blood pressure or the like to the display unit 40 . In addition, the processing device 30 may calculate a health index other than blood pressure, for example, an AI (arteriosclerosis index) value.

The digital filter 33 receives the detection signal obtained by irradiating the detection light from the first light source 111 to the living body, and the detection signal obtained by irradiating the detection light from the second light source 121 or the third light source 122 to the living body. Subtractive processing is performed. Here, since the pulse wave corresponding to the pulsation of the blood vessel appears repeatedly in the detection signal, a pulse wave of the living body can be obtained based on the detection signal.

The power management unit 34 controls the power supplied to the sensor unit 10 . For example, the power management unit 34 supplies a predetermined driving current to each of the first light source 111 , the second light source 121 , and the third light source 122 to provide the first light source 111 and the second light source. 121 and the third light source 122 emit light with a predetermined intensity. In addition, the power management unit 34 controls the timing of supplying current to each of the first light source 111, the second light source 121, and the third light source 122, and the first light source 111, the second light source ( 121) and the third light source 122 may intermittently emit light at a predetermined timing.

The display unit 40 outputs information such as a pulse wave or blood pressure of a living body indicated in the signal from the processing device 30 . As the display unit 40 , a liquid crystal display or an EL (Electro Luminescence) display can be used, for example.

Next, a biometric information acquisition method using the above-described biometric information acquisition device 1 will be described. The biometric information acquisition method of the present embodiment measures blood pressure according to the pulse wave of the living body. Fig. 4 is a flowchart showing the biometric information acquisition method according to the present embodiment. 5 is a diagram illustrating an example of emission timing of red light or infrared light and green light. 6 is a diagram showing another example of emission timing of red light or infrared light and green light. 7 is a diagram exemplarily illustrating a detection signal of a first detection unit input to a processing device. 8A and 8B are diagrams illustrating a waveform of a subtraction value obtained by subtracting a detection signal of a second detection unit from a detection signal of a first detection unit, and an example of a feature point extracted from the subtraction value and the subtraction value. 9A and 9B are diagrams for calculating the blood pressure of a living body according to extracted feature points and a regression line.

First, the biometric information acquisition device 1 is mounted on the wrist of a living body with, for example, a band, and as shown in FIG. 4 , the first light source 111 , the second light source 121 , and the third light source 122 . The detection light is respectively irradiated to the living body, and the reflected light from the living body is received by the light receiver 112 (S1).

In detail, based on the control signal from the processing device 30 , the first light source 111 does not overlap the light emission periods of the first light source 111 , the second light source 121 , and the third light source 122 . , the second light source 121 , and the third light source 122 emit light in a predetermined period and in a predetermined period.

In this embodiment, the pulse wave of the living body is sampled in advance, and, as shown in FIG. 5 , first, the first light source 111 emits light during approximately one cycle of the pulse wave, and then, the second light source 121 emits light of the same pulse wave. It emits light over a period of approximately one cycle. In addition, the third light source 122 emits light during approximately one cycle period of the corresponding pulse wave.

That is, light is irradiated to the living body in the order of the first light source 111 , the second light source 121 , and the third light source 122 every approximately one cycle of the pulse wave. Accordingly, the first light source 111 , the second light source 121 , and the third light source 122 may each be irradiated to the living body during a period from when the intensity of the detection signal is approximately the same.

In the present embodiment, the starting point of one cycle may not be the minimum point of the pulse wave, and is not particularly limited. In addition, in this embodiment, although the 1st light source 111, the 2nd light source 121, and the 3rd light source 122 are respectively irradiated in the whole of one cycle, as shown in FIG. 6, for example, The detection light of the light source 111 , the second light source 121 , and the third light source 122 may be intermittently emitted in the same period as the pulse wave and intermittently. Accordingly, power consumption of the first light source 111 , the second light source 121 , and the third light source 122 may be suppressed. In addition, the order of light emission of a light source is not specifically limited. In addition, in the embodiment, the light emission of the first light source 111 , the second light source 121 , and the third light source 122 is a set, but the present invention is not limited thereto.

As described above, red light or infrared light is reflected from blood vessels, and green light is reflected from peripheral blood vessels or fat near the dermis. For this reason, as shown in FIG. 3 , the detection light irradiated to the living body from the first light source 111 is reflected by the blood vessel, and the reflected light is received by the light receiver 112 . In addition, the detection light irradiated to the living body from the second light source 121 is reflected by peripheral blood vessels or fat near the dermis, and the reflected light is received by the light receiver 112 . In addition, the detection light irradiated to the living body from the third light source 122 is reflected by peripheral blood vessels or fat near the dermis, and the reflected light is received by the light receiver 112 . The light receiver 112 photoelectrically converts a signal indicating the intensity of the received light, and outputs an analog signal to the AFE 20 .

Next, the AFE 20 processes the detection signal input from the sensor unit 10 (S2). Specifically, the amplifier 21 of the AFE 20 amplifies the detection signal input from the sensor unit 10 based on the control signal of the processing device 30 . Then, the noise removal filter 22 of the AFE 20 removes noise by filtering the amplified detection signal based on the control signal of the processing device 30 . Also, the ADC 23 of the AFE 20 digitally processes the noise-removed detection signal based on the control signal of the processing device 30 , and outputs the digitally processed detection signal to the processing device 30 . For example, the ADC 23 of the AFE 20 outputs the detection signal of the first detection unit 11 having the waveform shown in FIG. 7 to the processing device 30 .

Next, the processing device 30 measures the blood pressure according to the detection signal input from the AFE 20 (S3). Between the epidermis and blood vessels, there are peripheral blood vessels and fat near the dermis. Noise based on reflected light reflected from the peripheral blood vessels or fat, etc. irradiates the detection light from the first light source 111 to the living body. It is included in the detection signal of the obtained reflected light.

Accordingly, the digital filter 33 of the processing device 30 detects the detection light from the second light source 121 or the third light source 122 from the detection signal of the reflected light obtained by irradiating the detection light from the first light source 111 to the living body. A pulse wave of the living body is obtained according to the subtraction value obtained by subtracting the detection signal of reflected light obtained by irradiating light to the living body. Then, the digital filter 33 outputs a detection signal indicating the subtracted value (that is, a detection signal indicating the pulse wave of the living body) to the CPU 31 .

Accordingly, it is possible to obtain a detection signal in which noise caused by reflection of the detection light from peripheral blood vessels or fat near the dermis can be obtained, and the accuracy of the measurement of the pulse wave of the living body can be improved.

On the other hand, from the detection signal of the reflected light obtained by irradiating the detection light from the first light source 111 to the living body, the detection signal of the reflected light obtained by irradiating the detection light from the second light source 121 or the third light source 122 to the living body is obtained. Since it is a simple process of subtraction, the arithmetic processing load of the processing device 30 can be reduced.

In the present embodiment, among the detection signals of the reflected light obtained by irradiating the detection light to the living body from the second light source 121 and the detection signals of the reflected light obtained by irradiating the detection light to the living body from the third light source 122, the detection signal is The one with the stronger intensity is selected, and the selected detection signal is subtracted from the detection signal of the reflected light obtained by irradiating the detection light to the living body from the first light source 111 . Accordingly, the pulse wave of the living body can be measured with higher precision.

Next, the CPU 31 of the processing device 30 measures the blood pressure according to the detection signal input from the digital filter 33 . In detail, as shown in FIGS. 8A and 8B , the CPU 31 receives, from a detection signal of reflected light obtained by irradiating a living body with detection light from the first light source 111, the second light source 121 or the second light source 121 3 One cycle of the pulse wave is specified from the period in which the subtraction value obtained by subtracting the detection signal of the reflected light obtained by irradiating the detection light from the light source 122 to the living body becomes positive. In the following description, a pulse wave corresponding to one cycle will be referred to as a pulse wave. The CPU 31 sets the timing at which the subtracted value becomes positive from negative as the starting point of the pulse wave. 8B shows the pulse wave of the living body by subtraction, and FIG. 8A shows an enlarged view of a part of the ideal living body pulse wave.

Then, the CPU 31 extracts the feature points of the pulse wave based on the subtracted value. The CPU 31 extracts, for example, a maximum value, a minimum value, a local maximum, a minimum value, an inflection point, and the like for each pulse wave as a feature point. The CPU 31 calculates the value and time of the feature point from the waveform of the subtracted value. For example, the CPU 31 calculates a characteristic point by differentiating the pulse wave to obtain a velocity pulse wave or by differentiating it twice to obtain an acceleration pulse wave.

In Fig. 8, the first peak (maximum) in one cycle becomes the systolic peak, and the second peak (maximum) becomes the reflective peak. In addition, the minimum value after the second peak becomes a notch indicating the boundary between the systolic and the diastolic. The time from the start of the circadian cycle to the systolic peak is referred to as the rise time (S. Time). Let the time from the start point of one cycle to the reflection peak (Reflective peak) be the reflection point time (R. Time). The time from the start point of the cycle to the notch point is referred to as the notch time. Also, the CPU 31 may extract the minimum value of one cycle as a feature point. In this way, the CPU 31 calculates the values and times at the plurality of feature points. In addition, in this embodiment, the maximum value, the minimum value, etc. may be corrected based on the subtraction value to a notch point.

The CPU 31 calculates the feature amount from the values and time of the plurality of feature points included in the pulse wave. In this specification, the characteristic quantity is a value for calculating the blood pressure (SBP, DBP), and is a value derived from the value and time of the characteristic point in the pulse wave. The feature quantity can be calculated according to a preset calculation formula.

Then, the CPU 31 converts the feature amount into blood pressure. The CPU 31 may convert the feature amount into a blood pressure value using a regression line. 9A shows a graph for calculating BP_MAX to the right, and FIG. 9B shows a graph for calculating BP_MIN. In this embodiment, as shown in FIGS. 9A and 9B , in order to calculate SBP (systolic blood pressure: BP_MAX) and DBP (diastolic blood pressure) (diastolic blood pressure: BP_MIN), two regression lines are stored in memory ( 32) is stored. Then, the CPU 31 calculates the feature amount for SBP and the feature amount for DBP based on the pulse wave. Then, the CPU 31 calculates SBP and DBP from the two feature quantities using the regression line, respectively. By processing in this way, the processing device 30 derives the blood pressure and outputs a signal indicating the blood pressure to the display unit 40 .

In addition, the regression line is set using a plurality of measurement results acquired in advance. For example, a feature amount is requested from the biometric information acquisition device according to the present embodiment for a plurality of measurement subjects, and blood pressure values are measured with a conventional calf type blood pressure monitor. In this way, a database in which the characteristic quantity and the blood pressure value are correlated is constructed. Then, a regression analysis is performed on the data stored in the database to obtain a regression line.

Here, the regression line may be set for each gender and age. For example, a man in his 20s, a woman in his 20s, a man in his 30s, a woman in his 30s, etc., may be set for each gender and each age. That is, data can be acquired for each age and gender, and a database can be built.

On the other hand, the CPU 31 is not limited to the regression straight line, and may convert the feature amount into blood pressure using a regression curve using a polynomial of a second or higher order or the like.

Furthermore, the CPU 31 may calculate the blood pressure based on the plurality of pulse waves. For example, the CPU 31 extracts a characteristic point for each of n pulse waves (n is an integer of 2 or more), and calculates a characteristic quantity. As a result, since the feature amount is calculated for each pulse wave, n features are calculated. Then, the CPU 31 converts each of the n feature quantities into blood pressure (SBP or DBP) using the regression line. Thereby, n blood pressure values are calculated. Then, the average value of the n blood pressure values can be used as the blood pressure. In this way, the measurement accuracy can be improved by calculating the feature amount based on the plurality of pulse waves.

Meanwhile, the blood pressure may be obtained by excluding the maximum or minimum values of the n blood pressure values. For example, among the n blood pressure values, the average value of (n-2) blood pressure values excluding the maximum and minimum values may be used as the blood pressure. Thereby, the measurement accuracy can be further improved.

On the other hand, the pulse wave (circadian period) from which the feature point cannot be extracted may be excluded from the calculation of the blood pressure. For example, when the maximum and minimum values necessary for calculating the feature amount are buried in the noise and cannot be calculated due to the influence of noise or the like, the feature amount cannot be calculated for the period. Therefore, it may be desirable not to convert the blood pressure for a pulse wave (circadian period) from which a feature point cannot be extracted. By doing in this way, the measurement precision of blood pressure can be improved.

In this way, the CPU 31 estimates the trend of rising and falling of the pulse wave based on the subtracted value, and estimates the maximum value, the minimum value, the maximum value, the minimum value, the inflection point, and the like as characteristic points. Then, for each pulse wave, the CPU 31 calculates a characteristic quantity from a plurality of characteristic points, and converts the characteristic quantity into a blood pressure value using a regression line obtained in advance from a database.

Next, the display unit 40 outputs the blood pressure indicated by the signal input from the processing device 30 (S4).

As described above, in this embodiment, from the detection signal of reflected light or transmitted light from blood vessels obtained by irradiating light of the first wavelength to the living body, reflected light or transmitted light near the dermis is large as noise obtained by irradiating light of the second wavelength to the living body. A pulse wave of the living body is obtained according to the subtracted value obtained by subtracting the detection signal of . Thanks to this, a detection signal with noise suppressed can be obtained, and the pulse wave of the living body and furthermore the blood pressure of the living body can be measured with high precision.

<Second embodiment>

In this embodiment, a different form of the sensor unit will be described. Fig. 10 is a diagram schematically showing the sensor unit of the present embodiment. In the sensor unit 50 of this embodiment, the same components as those of the biometric information acquisition device 1 of the above-described embodiment are described using the same reference numerals, and thus overlapping descriptions are omitted.

In the sensor unit 50 of this embodiment, as shown in FIG. 10 , the light source unit 51 in which the first light source 111 , the second light source 121 , and the third light source 122 are arranged on a substantially straight line is a substrate. On (13), the light receiver 112 is disposed in a radial direction. And the 1st light source 111, the 2nd light source 121, and the 3rd light source 122 of each light source unit 51 are respectively arrange|positioned on different substantially concentric circles. As used herein, the term "concentric circles" includes not only concentric circles in a strict sense, but also spirals and other cases that can be roughly regarded as concentric circles from the point of view of those skilled in the art.

That is, the first light source 111 of each light source unit 51 is arranged on a roughly first circular shape centered on the light receiver 112 . The second light source 121 of each light source unit 51 is arranged on an approximate second circle having a smaller diameter than the first circle centered on the light receiver 112 . In addition, the third light source 122 of each light source unit 51 is arranged on an approximate third circle smaller than the second circle centered on the light receiver 112 .

The pulse wave to be measured has a different waveform depending on the state in which the biometric information acquisition device is attached to the living body (for example, whether it is in contact or separated, and how much pressure it is). For this reason, the processing device 30 is configured to satisfy a predetermined condition among the light source units 51 (eg, the first light source 111 , the second light source 121 , and the third light source 122 at a predetermined pressure). ) selects the light source unit 51 (contacting the living body), respectively, and detects it from the first light source 111 , the second light source 121 , and the third light source 122 of the selected light source unit 51 , respectively By obtaining a pulse wave of the living body according to a detection signal obtained by irradiating light to the living body, it is possible to measure the pulse wave with high precision.

On the other hand, it is premised that the sensor unit 50 of this embodiment performs processing of subtracting a detection signal obtained by irradiating a living body with green light as detection light from a detection signal obtained by irradiating a living body with red light or infrared light as detection light. However, in the case where noise is not removed using a detection signal obtained by irradiating green light to a living body as detection light, all of the light sources mounted on the sensor unit 50 may be configured as the first light source 111 . At this time, the interval between the first light sources adjacent in the radial direction and the interval between the first light sources adjacent in the circumferential direction are appropriately set based on the wavelength of the emitted light or the like.

In this case, the detection signal obtained by irradiating the detection light to the living body from all of the first light sources 111 is sampled, and the signal state obtained by irradiating the detection light from the first light source 111 to the living body is the best (for example, , easy to extract feature points), a pulse wave of the living body is obtained according to the detection signal. Accordingly, it is possible to measure the pulse wave of the living body with high precision. That is, among the plurality of first light sources 111 arranged on a straight line, the signal state is the best, while among the plurality of first light sources 111 arranged on the same circle, it is possible to obtain a detection signal with the best signal state. A pulse wave of the living body is obtained according to the detection signal obtained by selecting the first light source 111 and irradiating the detection light from the first light source 111 to the living body.

On the other hand, in the case of creating a database as described above by classifying sex, age, weight, etc., and collecting data by setting the distance from the light receiver 112 to the first light source 111 to be constant, as described above, the first When the light sources 111 are arranged in a substantially concentric circle, the distance from the first light source 111 arranged in the same circle to the light receiver 112 is approximately the same, so that the error of the blood pressure estimation algorithm by the corresponding database can be suppressed. have.

On the other hand, when the first light sources 111 are arranged substantially concentrically as described above, compared to the case where the first light sources 111 are arranged in a matrix shape on the substrate 13 , the first light sources 111 ) can be reduced, and as a result, it is possible to contribute to weight reduction of the biometric information acquisition device.

On the other hand, Patent Document 2 (Patent No. 2766317) discloses a configuration in which a light-emitting element is arranged on a circle centered on a light-receiving element, but it is a technique for measuring oxygen saturation in blood.

<Third embodiment>

Another embodiment of the sensor unit in the case where noise is not removed using a detection signal obtained by irradiating a green light to a living body as a detection light will be described. 11 is a diagram schematically showing the sensor unit of the present embodiment. In the sensor unit 60 of the present embodiment, the same components as those of the biometric information acquisition device 1 of the above-described embodiment are described using the same reference numerals, and thus overlapping descriptions are omitted.

In the sensor unit 60 of this embodiment, as shown in FIG. 11 , the light receiver unit 61 in which a plurality of light receivers 112 are arranged on a substantially straight line forms a first light source 111 on a substrate 13 . It is arranged radially centered on the center. And the light receiver 112 of each light receiver unit 61 is respectively arrange|positioned on different substantially concentric circles. In this case, the distance between the light receivers 112 adjacent in the radial direction and the distance between the light receivers 112 adjacent in the circumferential direction may be appropriately set based on the wavelength of the light emitted from the first light source 111 .

As described above, since the measured pulse wave has a different waveform depending on the state in which the biometric information acquisition device is attached to the living body, a predetermined condition is satisfied (for example, a predetermined pressure is applied to the living body by a predetermined pressure in each of the light receivers 112 ). By selecting the light receiver 112 (which is in contact) and obtaining a pulse wave of a living body according to the detection signal of the selected light receiver 112, the measurement accuracy of the pulse wave can be improved.

On the other hand, in the case of creating a database as described above by classifying gender, age, weight, etc., and collecting data in a state where the distance from the first light source 111 to the light receiver 112 is constant, as described above, When the light receiver 112 is arranged in a substantially concentric circle, the distance to the first light source 111 is approximately constant between the light receiver 112 in the same approximate circular shape, and thus the error of the blood pressure estimation algorithm based on the database is suppressed. can do.

On the other hand, compared to the case of arranging the light receivers 112 in a matrix shape on the substrate 13, if the light receivers 112 are arranged substantially concentrically as described above, the number of the light receivers 112 can be reduced. As a result, it can contribute to weight reduction of the biometric information acquisition device.

<Fourth embodiment>

Another embodiment of the sensor unit in the case where noise is not removed using a detection signal obtained by irradiating a green light to a living body as detection light will be described. 12 is a diagram schematically showing the sensor unit of the present embodiment. The same components as the biometric information acquisition device 1 of the above-described embodiment in the sensor unit 70 of the present embodiment are described using the same reference numerals, and thus overlapping descriptions are omitted.

In the sensor unit 70 of the present embodiment, as shown in FIG. 12 , a light receiver 112 is provided on a substrate 13 on a substantially spiral (indicated by a dashed dotted line in FIG. 12 ) centered on the first light source 111 . ) is placed on the Even in this case, by selecting a light receiving unit 112 that satisfies a predetermined condition among the plurality of light receiving units 112 and obtaining a living body pulse wave according to the detection signal of the selected light receiving unit 112, the measurement accuracy of the pulse wave is improved. can be improved In this case, the interval between the light receivers 112 adjacent to each other in a spiral shape may be appropriately set based on the wavelength of the light emitted from the first light source 111 .

On the other hand, in the present embodiment, although the light receiver 112 is disposed on a substantially spiral shape centered on the first light source 111, the first light source 111 is disposed on a substantially spiral shape centered on the light receiver 112, A pulse wave of the living body may be obtained according to a detection signal of reflected light obtained by selecting the first light source 111 that satisfies a predetermined condition and irradiating the detection light to the living body from the selected first light source 111 .

<Fifth embodiment>

Another embodiment of the sensor unit in the case where noise is not removed using a detection signal obtained by irradiating a green light to a living body as detection light will be described. Fig. 13 is a diagram schematically showing the sensor unit of the present embodiment. The sensor unit 80 of this embodiment is described by using the same reference numerals for the same components as those of the biometric information acquisition device 1 of the above-described embodiment, and thus overlapping descriptions are omitted.

In the sensor unit 80 of the present embodiment, as shown in FIG. 13 , the first light source 111 and the plurality of light receivers 112 are arranged on a substrate 13 on a substantially straight line. Even in this case, by selecting a light receiving unit 112 that satisfies a predetermined condition from among the plurality of light receiving units 112 , and obtaining a living body pulse wave according to the detection signal of the selected light receiving unit 112 , the measurement accuracy of the pulse wave can improve

On the other hand, in the present embodiment, although the first light source 111 and the plurality of light receivers 112 are arranged on a substantially straight line, the light receiver 112 and the plurality of first light sources 111 are arranged on a substantially straight line, The first light source 111 satisfying a predetermined condition may be selected, and a pulse wave of the living body may be obtained according to a detection signal obtained by irradiating a detection light from the selected first light source 111 to the living body.

<Sixth embodiment>

Another embodiment of the sensor unit in the case where noise is not removed using a detection signal obtained by irradiating a living body with green light as detection light will be described. Fig. 14 is a diagram schematically showing the sensor unit of the present embodiment. The sensor unit 90 of the present embodiment is described by using the same reference numerals for the same components as those of the biometric information acquisition device 1 of the above-described embodiment, and thus overlapping descriptions are omitted.

In the sensor unit 90 of the present embodiment, as shown in FIG. 14 , a light source 91 is disposed on a substrate 13 centered on a light receiver 112 on a plurality of substantially rings having different diameters. Also in this case, among the light sources 91 , a light source 91 satisfying a predetermined condition (for example, contacting the living body with a predetermined pressure) is selected, and the detection light is irradiated to the living body from the selected light source 91 . By obtaining a pulse wave of a living body according to the obtained detection signal, it is possible to improve the measurement accuracy of the pulse wave. Here, the interval between the adjacent light sources 91 may be appropriately set based on the wavelength of the emitted light or the like.

On the other hand, in the present embodiment, although the light source 91 is disposed on a ring centered on the light receiver 112, the light receiver is disposed on a plurality of rings centered on the point light source, and a light receiver satisfying a predetermined condition is provided. Optionally, the pulse wave of the living body may be measured according to the detection signal of the selected light receiver.

<Seventh embodiment>

The substrate 13 may be configured as a flexible substrate. Thereby, the board|substrate 13 can be made to conform to the curve of a living body, for example, a wrist, and a light source and a light-receiver can be brought into favorable contact with a living body.

As described above, when the bio-information acquisition device in which the substrate 13 is made of a flexible substrate is mounted on a living body, the substrate 13 is curved and the concentric circles described above can be deformed. That is, in a state in which the biometric information acquisition device is mounted on the living body, in a state in which the substrate 13 is flattened so that the light source or the light receiver is arranged in a substantially concentric circle, one of the light source and the receiver is centered on the other. It can be arranged on one concentric ellipse. Thereby, when creating a database, the distance between the 1st light source 111 and the light receiver 112 arrange|positioned on the same substantially circular shape can be made constant at a high level.

<Eighth embodiment>

As described above, when the contact pressure of the light source or the light receiver to the living body is detected, the following configuration can be adopted. Fig. 15 is a diagram schematically showing a sensor unit having a configuration capable of detecting the contact pressure of the first light source to the living body.

The sensor unit of this embodiment is provided with the pressure detection part 14 between the board|substrate 13 and the 1st light source 111 as shown in FIG. As the pressure detection unit 14 , a general pressure sensor can be used.

When such a configuration is employed, for example, in a sensor unit including the plurality of first light sources 111 , the processing device based on the detection signal of the pressure detection unit 14 , among the plurality of first light sources 111 , a preset pressure A pulse wave of the living body is obtained according to a detection signal obtained by selecting the first light source 111 that is higher than or equal to the value, and irradiating the detection light to the living body from the selected first light source 111 . In this way, it is possible to avoid measurement difficulties due to variations in the mounting state of the biometric information acquisition device on the living body or individual differences in the living body.

On the other hand, in FIG. 15 , the first light source 111 has a configuration capable of detecting the contact pressure to the living body. For example, in the case of a sensor unit including a plurality of light receivers 112 , What is necessary is just to arrange|position the pressure detection part 14 between 112 and the board|substrate 13.

<Ninth embodiment>

Here, it may be desirable to have a configuration in which the contact pressure of the light source or the light receiver to the living body can be adjusted to a preset value. Fig. 16 is a diagram schematically showing a configuration in which the contact pressure of the first light source to the living body can be adjusted to a preset value.

In the present embodiment, as shown in FIG. 16 , a pressure detecting unit 14 and a pressure adjusting unit 15 are provided between the first light source 111 and the substrate 13 . As the pressure adjusting part 15, an actuator can be used, for example.

If such a configuration is employed, for example, in a sensor unit having a plurality of first light sources 111 , the processing device controls the pressure adjusting unit 15 according to the detection signal from the pressure detecting unit 14 , and the first light sources 111 . ) to adjust the contact pressure to the living body to a preset value. Then, the processing device obtains a pulse wave of the living body according to the detection signal obtained by irradiating the detection light to the living body from the plurality of first light sources 111 and having the best signal state (eg, the feature point is easy to extract). In this way, it is possible to avoid measurement difficulties due to variations in the mounting state of the biometric information acquisition device on the living body or individual differences in the living body.

On the other hand, in FIG. 16 , although the first light source 111 has a configuration that can be adjusted by the contact pressure to the living body, for example, in the case of a sensor unit including a plurality of light receivers 112, each light receiver 112 What is necessary is just to arrange|position the pressure detection part 14 and the pressure adjustment part 15 between and the board|substrate 13.

<Embodiment 10>

In the case of using a sensor unit having a plurality of first light sources 111 or a plurality of light receivers 112 , a plurality of first light sources 111 and a plurality of light receivers 112 having different distances from either side of the central first light source 111 or light receiver 112 are used. By operating the other first light source 111 or the light receiver 112, the blood pressure of the living body may be derived based on the pulse wave obtained at a different location by the living body in a general PWTT (Pulse Wave Transit Time) method.

<Eleventh embodiment>

When the sensor unit includes the plurality of first light sources 111 , it may be desirable to change the frequency of the emitted light of the first light source according to the distance from the light receiver 112 . For example, the frequency of the light emitted from the first light source 111 increases as it moves away from the light receiver 112 . Accordingly, it is possible to adjust the degree of reaching the depth of the light emitted from the first light source 111 in the living body.

<Twelfth embodiment>

17 is a diagram schematically showing a wristwatch-type terminal, and FIG. 18 is a rear view of the wristwatch-type terminal of FIG. 17 and 18 , the wristwatch-type terminal 200 may include a main body 210 , a sensor unit 220 , and a display unit 230 provided on the front surface 210a of the main body 210 . can The sensor unit 220 is disposed on the rear surface 210b of the body 210 to be in contact with the wrist of the living body. This sensor unit 220 may be the sensor units 10, 50, 60, 70, 80, 90 of the above-described embodiments. The body 210 is worn on the wrist of the living body by the band 250 , and accordingly, the sensor unit 220 comes into contact with the skin of the wrist. An AFE ( 20 in FIG. 1 ), a processing device ( 30 in FIG. 1 ), etc. may be built in the body 210 . The display unit 230 may display blood pressure (SBP, DBP) and the like. Of course, the display unit 230 may display the time independently or together with the blood pressure.

In the above, embodiments of the biometric information acquisition device, wrist watch-type terminal, and biometric information acquisition method related to the present invention have been described. do.

For example, in the above-described embodiments, the pulse wave of the living body is measured according to the reflected light reflected by the detection light in the living body. In this case, the light source and the light receiver may be arranged so that the living body is positioned between the light source and the light receiver.

For example, in some embodiments described above, although a sensor unit having a plurality of first light sources 111 or light receivers 112 has been described, it is not limited to the above-described configuration. That is, the plurality of first light sources 111 or light receivers 112 may be arranged irregularly or regularly on the substrate 13 .

For example, it is also possible to embed the biometric information acquisition device of the above-described embodiment in a simple wrist band or other wearable terminal capable of coming into contact with a living body in addition to a wrist watch-type terminal. In addition, the wearable terminal is provided with a wireless communication unit together with the sensor units 10, 50, 60, 70, 80, 90, but other configurations (eg, the processing device 30, the display unit 40, etc.) are smart It may be provided in the phone. In this case, analog data or digital data acquired from the wristwatch-type terminal is transmitted to the smart phone by the wireless communication unit. Incidentally, the smart phone receiving the data may perform part or all of the processing for measuring the blood pressure.

1: biometric information acquisition device 10: sensor unit
11: first detection unit 111: first light source
112: light receiver 12: second detection unit
121: second light source 122: third light source
13: substrate 14: pressure detection unit
15: pressure regulator 20: AFE
21: Amplifier 22: Noise Removal Filter
23: ADC 30: processing unit
31: filter 32: memory
33: digital filter 34: power management unit
40: display unit 50: sensor unit
51: light source unit 60: sensor unit
61: receiver unit 70: sensor unit
80: sensor unit 90: sensor unit
91 light source

Claims (28)

a first detection unit irradiating light of a first wavelength to the living body to detect reflected light or transmitted light in the living body;
a second detection unit irradiating light of a second wavelength to the living body to detect reflected light or transmitted light in the living body; and
a processing unit for calculating a pulse wave according to a subtraction value obtained by subtracting a detection signal obtained by irradiating light of the second wavelength from a detection signal obtained by irradiating light of the first wavelength;
The irradiation of the light of the first wavelength to the living body and the irradiation of the light of the second wavelength to the living body are performed in substantially the same period at a preset period so that the irradiation period does not overlap,
The preset period is substantially the same as the pulse wave period of the living body. According to claim 1,
The light of the first wavelength is a red light or an infrared light. According to claim 1,
The light of the second wavelength is green light. According to claim 1,
The light of the first wavelength is scattered and reflected or transmitted in blood vessels deeper than the dermis of the living body, and the light of the second wavelength is scattered and reflected or transmitted near the dermis of the living body. According to claim 1,
The first detection unit includes a first light source emitting light of a first wavelength, and a first light receiver for detecting reflected light or transmitted light emitted from the first light source and irradiated to the living body,
The second detector includes a second light source for emitting light of a second wavelength, and a second light receiver for detecting reflected light or transmitted light emitted from the second light source and irradiated to the living body, and the first light source and The first light receiver is disposed to be more spaced apart than a distance between the second light source and the second light receiver. 6. The method of claim 5,
The second light receiver is a biometric information acquisition device in common with the first light receiver. delete delete A wristwatch-type terminal provided with the biometric information acquisition device according to any one of claims 1 to 6. detecting reflected light or transmitted light in a living body by irradiating light of a first wavelength;
detecting reflected light or transmitted light in a living body by irradiating light of a second wavelength; and
calculating a biological pulse wave according to a subtraction value obtained by subtracting a detection signal obtained by irradiating light of the second wavelength from a detection signal obtained by irradiating light of the first wavelength;
The irradiation of the light of the first wavelength to the living body and the irradiation of the light of the second wavelength to the living body are performed in substantially the same period at a preset period so that the irradiation period does not overlap,
The preset period is substantially the same as the pulse wave period of the living body. 11. The method of claim 10,
The light of the first wavelength is red light or infrared light. 11. The method of claim 10,
The light of the second wavelength is green light. 11. The method of claim 10,
The light of the first wavelength is reflected or transmitted by being scattered in a blood vessel deeper than the dermis of the living body, and the light of the second wavelength is scattered and reflected or transmitted near the dermis of the living body. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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