JP2017189327A - Biological information acquisition device and biological information acquisition method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for accurately acquiring biological information.SOLUTION: A biological information acquisition device acquires N sets of one set of light-receiving results constituted by a first light-receiving result and a second light-receiving result by selecting N pairs (N is an integer of 2 or more) of light-receiving sections for measurement and light-receiving sections for reference and executing light-receiving processing for selecting light-receiving sections separated from a light-emitting section for measurement by second distances as the light-receiving sections for reference and acquiring the second light-receiving result while selecting the light-receiving sections separated from the light-emitting section for measurement by the second distances greater than first distances as light-receiving sections for measurement out of a plurality of light-receiving sections receiving light irradiated from the light-emitting section for measurement and acquiring the first light-receiving result, and acquires biological information by using the N sets of light-receiving results.SELECTED DRAWING: Figure 13

Description

  The present invention relates to a biological information acquisition apparatus and a biological information acquisition method.

  Conventionally, a biological information acquisition device that acquires biological information related to blood vessels and blood in blood vessels is known (for example, Patent Document 1). In Patent Document 1, the light emitted from the light emitting element present at the irradiation position includes (i) the light reception result obtained by the light receiving element present at the measurement light receiving position, and (ii) the reference present at the reference light receiving position. The fact that biometric information is acquired using the light reception result acquired by the light receiving element for use is described.

  In the techniques of Patent Documents 1 and 2, the positional relationship among the irradiation position, the measurement light reception position, and the reference light reception position is as follows. That is, (i) the blood vessel part to be measured is located in the center between the irradiation position and the light receiving position for measurement, and (ii) there is no blood vessel part to be measured between the light irradiation position and the light receiving position for reference. Is located. The reference light receiving position is on an extension line connecting the irradiation position and the measurement light receiving position, and is located on the opposite side of the measurement light receiving position as viewed from the irradiation position.

JP2015-142666A JP 2014-124455 A

  However, in the techniques of Patent Documents 1 and 2, the measurement light receiving position and the reference light receiving position are separated from the irradiation position. For this reason, the structure of the living body in the optical path in which the light emitted from the measurement light emitting position travels to the light receiving position for measurement may be significantly different from the structure of the living body in the optical path in which the light emitted from the measurement light emitting position proceeds to the reference. Therefore, there are cases where biological information cannot be obtained with sufficient accuracy in obtaining biological information related to blood vessels. For this reason, the technique which acquires the biological information relevant to the blood vessel accurately was desired.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

(1) According to the first aspect of the present invention, a biological information acquisition apparatus is provided. The biological information acquisition apparatus is configured to control a plurality of light emitting units that irradiate light to a living body, a plurality of light receiving units that receive light transmitted through the living body, and the plurality of light emitting units and the plurality of light receiving units. A biological information acquisition device comprising: a control unit, wherein the control unit identifies a position of a blood vessel of the living body by causing at least one of the plurality of light emitting units to emit light, and among the plurality of light emitting units, A light emitting unit that is separated from the blood vessel by a first distance is selected as a measurement light emitting unit to emit light, and light emitted from the measurement light emitting unit is transmitted from the measurement light emitting unit among the plurality of light receiving units. The light receiving unit that is separated by a second distance larger than the first distance is selected as the measurement light receiving unit to obtain the first light reception result, and is separated from the measurement light emitting unit by the second distance. Select the receiver as the reference receiver Then, the light reception process for acquiring the second light reception result is performed by selecting N pairs (N is an integer of 2 or more) of the measurement light reception units and the reference light reception unit, and thereby executing the first light reception result and N sets of light reception results including the second light reception results are acquired, biometric information is acquired using the N sets of light reception results, and the N pairs of measurement light reception units and reference light reception units are obtained. (I) a first line segment connecting the measurement light emitting part and the measurement light receiving part passes over the blood vessel, and (ii) ) The second line segment connecting the measurement light emitting unit and the reference light receiving unit does not pass over the blood vessel, and (iii) the angle formed by the first line segment and the second line segment The condition that the angle is 45 ° or less is selected.
The angle formed by the first line segment connecting the measurement light emitting unit and the measurement light receiving unit and the second line segment connecting the measurement light emitting unit and the reference light receiving unit is 45 ° or less. The structure of the living body in the optical path in which the light emitted from the measurement light emitting section travels to the light receiving section for measurement is a point other than the structure of the living body in the optical path in which the light emitted from the light emitting section for reference travels to the light receiving section for reference Therefore, according to the biological information acquisition apparatus of this embodiment, biological information related to blood vessels can be acquired with high accuracy. Moreover, according to the biological information acquisition apparatus of this embodiment, since biological information is acquired using N sets of light reception results, biological information related to blood vessels can be acquired with high accuracy.

(2) The biometric information acquisition apparatus includes a sensor module having a plurality of light emitting elements and a plurality of light receiving elements regularly arranged in a light receiving / emitting region, and the control unit includes one of the light receiving / emitting regions. A light emitting region having a certain shape and size may be selected as the region of the part, and a plurality of light emitting elements in the light emitting region may emit light as the measurement light emitting unit.
Since one light emitting unit is formed by a set of a plurality of smaller light emitting elements, the position of the light emitting unit can be selected in units of the pitch of the small light emitting elements. Thus, the degree of freedom for selecting the light emitting unit is improved. Moreover, compared with the case where one light emission part is formed with one light emitting element, the biological information acquisition apparatus of this embodiment can obtain sufficient light emission intensity. As a result, according to the biological information acquisition apparatus of this embodiment, biological information related to blood vessels can be acquired with high accuracy.

(3) The biometric information acquisition apparatus includes a sensor module having a plurality of light emitting elements and a plurality of light receiving elements regularly arranged in a light receiving / emitting region, and the control unit includes a sensor module having one of the light receiving and emitting regions. The first light receiving region and the second light receiving region having a certain shape and size are selected as the region of the part, and a plurality of light receiving elements in the first light receiving region are received as the measurement light receiving unit, and the second light receiving region is received. A plurality of light receiving elements in the light receiving area may be received as the reference light receiving unit.
Since one light receiving unit is formed by a set of a plurality of smaller light receiving elements, the position of the light receiving unit can be selected in units of the pitch of the small light receiving elements. Thus, the degree of freedom for selecting the light receiving portion is improved. Moreover, compared with the case where one light-receiving part is formed with one light-receiving element, the biological information acquisition apparatus of this embodiment can obtain sufficient light-receiving intensity. As a result, according to the biological information acquisition apparatus of this embodiment, biological information related to blood vessels can be acquired with high accuracy.

(4) In the biological information acquisition apparatus, the biological information may include a glucose concentration in blood of the biological body.
According to the biological information acquisition apparatus of this embodiment, the glucose concentration in blood can be acquired.

(5) In the biological information acquisition apparatus, the biological information may include oxygen saturation in blood of the living body.
According to the biological information acquisition apparatus of this embodiment, the oxygen saturation in blood can be acquired.

  The present invention can be realized in various forms other than the above-described forms. For example, a living body including a plurality of light emitting units that irradiate light to a living body and a plurality of light receiving units that receive light transmitted through the living body. Realization of a biological information acquisition method for acquiring biological information by an information acquisition device, a computer program for realizing this method, a non-transitory storage medium for storing the computer program, and the like Is possible.

The schematic diagram which shows the structure of the biometric information acquisition apparatus in 1st Embodiment. The plane schematic diagram which shows a part of sensor module. The block diagram of a sensor module. The schematic diagram explaining a mode that a blood vessel pattern (blood vessel position) is acquired. The figure which shows the example of the blood vessel pattern obtained based on a biometric image. FIG. 6 is an example of a blood vessel part to be measured obtained based on the blood vessel pattern of FIG. 5. The figure explaining selection of a light emission part and a light-receiving part. The figure explaining the propagation of the light in a biological tissue. The figure which shows the relationship between a light emission part and a light emitting element, and the relationship between a light-receiving part and a light receiving element. The functional block diagram of the blood glucose level measuring apparatus in this embodiment. The figure which shows an example of a data structure of the vascular site | part data. The flowchart explaining the flow of a blood glucose level measurement process. The figure explaining selection of the light emission part and light-receiving part in 2nd Embodiment. The flowchart explaining the flow of the blood glucose level measurement process in 2nd Embodiment.

A. First embodiment:
A1. Device configuration:
FIG. 1 is a schematic diagram illustrating a configuration of a biological information acquisition apparatus 10 according to the first embodiment. The biological information acquisition device 10 is a biological information acquisition device that non-invasively measures the biological information of the user 2 using light. In the present embodiment, a blood glucose level that is a glucose concentration in the blood of the user 2 is acquired as the biological information. The biological information acquisition apparatus 10 is also referred to as a blood glucose level measurement apparatus 10. The biological information acquisition device 10 is a wristwatch type, and includes a main body case 12 and a wearable device including a fixing band 14 for mounting and fixing the main body case 12 to a measurement site such as a wrist or an arm of the user 2. (Wearable device).

  A touch panel 16 and operation switches 18 are provided on the surface of the main body case 12 (the surface facing outward when the user 2 is worn). By using the touch panel 16 and the operation switch 18, the user 2 can input a measurement start instruction and the measurement result can be displayed on the touch panel 16.

  A communication device 20 for communicating with an external device and a reader / writer 24 for the memory card 22 are provided on the side surface of the main body case 12. The communication device 20 is realized by a jack for attaching / detaching a wired cable, or a wireless communication module and an antenna for performing wireless communication. The memory card 22 is a nonvolatile memory capable of rewriting data such as a flash memory, a ferroelectric memory (FeRAM: Ferroelectric Random Access Memory), and a magnetoresistive memory (MRAM).

  A sensor module 50 is provided on the back surface of the main body case 12 so as to be in contact with the skin surface of the user 2. The sensor module 50 is a measurement device that irradiates the skin surface of the user 2 with measurement light and receives light transmitted through or reflected by the body of the user 2, and is a thin image sensor with a built-in light source.

Further, the main body case 12 contains a rechargeable battery 26 and a control board 30. As a charging method for the battery 26, an electrical contact may be provided on the back side of the main body case 12, set in a cradle connected to a household power source, and charged via the cradle via the electrical contact, or wirelessly. Charging can be used.

  The control board 30 includes a CPU (Central Processing Unit), a main memory, a measurement data memory, a touch panel controller, and a sensor module controller. The main memory is a storage medium that can store programs and initial setting data, and can store CPU calculation values, and is realized by a RAM, a ROM (Read Only Memory), a flash memory, or the like. Note that the program, the initial setting data, and the configuration stored in the memory card 22 may be used. The measurement data memory is a storage medium for storing measurement data, and is realized by a rewritable nonvolatile memory such as a flash memory, a ferroelectric memory (FeRAM), or a magnetoresistive memory (MRAM). The measurement data may be stored in the memory card 22.

  2 and 3 are configuration diagrams of the sensor module 50. FIG. FIG. 2 is a schematic plan view showing a part of the sensor module 50, and FIG. 3 is a schematic cross-sectional view of the sensor module 50. As shown in FIG. 2, the sensor module 50 includes a plurality of light emitting elements 53 and a plurality of light receiving elements 59 that are regularly arranged in the light receiving and emitting region. Here, the light receiving / emitting region refers to a region including a plurality of light emitting elements 53 and light receiving elements 59.

  As shown in FIG. 3, the sensor module 50 includes a light emitting layer 52 in which a large number of light emitting elements 53 are two-dimensionally arranged in a plane, a light shielding layer 54 that selectively blocks light other than light directed to the light receiving layer 58, and a near infrared ray. Is an optical sensor configured by laminating a spectral layer 56 that selectively transmits light and a light receiving layer 58 in which a large number of light receiving elements 59 are two-dimensionally arranged in a plane. And this sensor module 50 is provided in the back surface side of the main body case 12 so that the front side (surface by the side of the light emitting layer 52) may face the user's 2 skin surface.

  The light emitting element 53 is a part that irradiates light to a living body, and is realized by, for example, an LED (Light Emitting Diode) or an OLED (Organic light-emitting diode). In this embodiment, in order to measure a blood glucose level (glucose concentration in blood), the light emitting element 53 is an element capable of emitting light including near infrared rays having subcutaneous permeability.

  The light receiving element 59 is a part that receives light transmitted or reflected through a living body and outputs an electrical signal corresponding to the amount of light received. For example, a charge coupled device image sensor (CCD), a complementary metal oxide semiconductor image sensor (CMOS) This is realized by an image sensor. Further, one light receiving element 59 includes a plurality of elements that receive each wavelength component necessary for calibration.

  As shown in FIG. 2, the light emitting elements 53 and the light receiving elements 59 are arranged in a matrix defined by a common Xs-Ys orthogonal coordinate system. The light emitting element 53 and the light receiving element 59 have the same arrangement interval in the Xs and Ys axis directions, but are arranged to be staggered in the Xs-Ys plane. In other words, the Xs and Ys axis positions of the light emitting element 53 and the light receiving element 59 are arranged so as to deviate from each other by a predetermined length.

  In addition, the arrangement | positioning space | interval of each of the light emitting element 53 and the light receiving element 59 can be set suitably. For example, the arrangement interval is preferably 1 to 500 μm, and can be set to 50 to 200 μm, for example, in consideration of the manufacturing cost and the measurement accuracy. The light emitting element 53 and the light receiving element 59 are not limited to the stacked structure, and the light emitting element 53 and the light receiving element 59 may be juxtaposed.

A2. Measuring principle:
(A) Measurement of blood glucose level The measurement principle of blood glucose level in the present embodiment will be described. In the measurement, the blood glucose level measuring device 10 is fixed by the fixing band 14 so that the sensor module 50 is in close contact with the skin surface of the user 2. By closely attaching the sensor module 50 to the skin surface, it is possible to suppress factors that lower the measurement accuracy, such as reflection of measurement light on the skin surface and scattering near the skin surface. Then, a blood vessel in a living tissue immediately below the sensor module 50 is set as a measurement target, the measurement light receives light including transmitted light that has passed through the blood vessel, an absorption spectrum is obtained, and a blood glucose level is estimated and calculated.

(A-1) Acquisition of blood vessel pattern Specifically, first, a blood vessel pattern (blood vessel position) viewed from the skin surface is acquired. Acquisition of a blood vessel pattern can be realized in the same manner as vein pattern detection in a known vein authentication technique.

  FIG. 4 is a schematic diagram for explaining how a blood vessel pattern (blood vessel position) is acquired. As shown in FIG. 4, the light emitting elements 53 of the sensor module 50 emit light all at once, and the measurement light is irradiated onto the skin surface of the user 2. Then, using all the light receiving elements 59, the measurement light is received, that is, photographed, the light transmitted through the biological tissue (transmitted light) and the light reflected by the biological tissue (reflected light) to obtain a biological image. Note that only part of the light emitting elements 53 of the sensor module 50 may emit light when acquiring a biological image.

  Since the blood vessel absorbs near infrared rays more easily than the non-blood vessel portion, the blood vessel portion is darker and darker than the non-blood vessel portion in the acquired biological image. For this reason, a blood vessel pattern can be extracted by extracting the part where the brightness | luminance is low in a biological image. That is, for each pixel constituting the living body image, whether or not a blood vessel exists immediately below the corresponding light receiving element 59, that is, the position of the blood vessel, can be acquired depending on whether or not the luminance is equal to or less than a predetermined threshold value. it can.

  FIG. 5 is a diagram illustrating an example of a blood vessel pattern P4 obtained based on a biological image. The blood vessel pattern P4 is information indicating whether it is a blood vessel or a non-blood vessel region for each pixel constituting the living body image, that is, for each position of the light receiving element 59. In FIG. 5, the shaded band-like part is the blood vessel 4, and the other white part is extracted as the non-blood vessel region 8.

(A-2) Selection of blood vessel part to be measured Once a blood vessel pattern is acquired, subsequently, a blood vessel (more specifically, a blood vessel part) to be measured is selected. The blood vessel part to be measured is selected so as to satisfy the following selection condition. The selection condition is “a part other than a branching part or a merging part of a blood vessel or an end part of an image and having a predetermined length and a predetermined width in the longitudinal direction of the blood vessel”.

  In the branching / merging portion 5a of the blood vessel (see FIG. 5), there is a possibility that light that has passed through a blood vessel other than the measurement target is mixed with the received light. The transmitted light of blood vessels other than the blood vessel part to be measured affects the absorption spectrum of the blood vessel part to be measured, which may reduce the measurement accuracy. For this reason, the blood vessel part to be measured is selected from the blood vessel part excluding the blood vessel branching / merging part 5a.

  In addition, since the structure such as branching and merging of blood vessels near the outside of the image is unknown at the end portion 5b (see FIG. 5) of the living body image, there is a possibility that measurement accuracy may be lowered due to the same reason as described above. In order to avoid this, the blood vessel part to be measured is selected from the blood vessel part excluding the image end portion 5b.

  Irradiation light from the light emitting element 53 is diffusely reflected in the living tissue, and a part thereof is received by the light receiving element 59. That is, a part of the light received by the light receiving element 59 becomes the transmitted light of the target blood vessel, and the higher the ratio of this transmitted light, the more the absorption spectrum that more significantly represents the characteristics of the blood components of the target blood vessel. obtain. That is, the measurement accuracy is increased.

  A blood vessel that is relatively thin (a blood vessel having a short width in the width direction) is essentially a thin blood vessel or a blood vessel that is relatively deep. In such blood vessels, the amount of transmitted light is reduced, and the measurement accuracy may be reduced. For this reason, the blood vessel part to be measured is selected from the blood vessel part excluding the thinly drawn blood vessel (that is, a blood vessel part having a predetermined width).

  FIG. 6 is an example of the blood vessel portion 6 to be measured obtained based on the blood vessel pattern P4 of FIG. In FIG. 6, the hatched portion of the blood vessel 4 is the blood vessel portion 6 selected as the measurement target.

(A-3) Selection of light emitting unit and light receiving unit Subsequently, the light emitting unit L and the light receiving unit S are selected.

  FIG. 7 is a diagram illustrating selection between the light emitting unit L and the light receiving unit S. In the present embodiment, (i) the light emitting unit L that is separated from the blood vessel by the distance X (first distance) is selected as the measurement light emitting unit Ld. Here, “the light emitting portion L separated from the blood vessel by a distance X” means that the center of the light emitting portion L is separated from the blood vessel boundary by a distance X ± 10%.

  Further, (ii) a light receiving part S separated from the measurement light emitting part Ld by a distance W (second distance) larger than the distance X is selected as the measurement light receiving part Sd, and similarly (iii) measurement light emission. The light receiving part S separated by the distance W from the part Ld is selected as the reference light receiving part Sr. Here, “the light receiving part S separated from the measurement light emitting part Ld by the distance W” means that the center of the light receiving part S is separated from the center of the measurement light emitting part Ld by a distance W ± 10%. .

  The first line segment N1 connecting the measurement light emitting part Ld and the measurement light receiving part Sd passes over the blood vessel, and the second line segment N2 connecting the measurement light emitting part Ld and the reference light receiving part Sr is Do not pass over blood vessels. Here, the “first line segment N1” means a line segment connecting the center of the measurement light emitting unit Ld and the center of the measurement light receiving unit Sd, and “the first line segment N1 is an upper part of the blood vessel. The term “passes through” means that the first line segment N1 passes through the center line of the blood vessel and crosses the boundary line in the width direction of the blood vessel twice. Further, the “second line segment N2” means a line segment connecting the center of the measurement light emitting unit Ld and the center of the reference light receiving unit Sr, and “the second line segment N2 is above the blood vessel. The term “does not pass” means that the second line segment N2 never crosses the boundary line of the blood vessel.

  In addition, the angle θ formed by the first line segment N1 and the second line segment N2 is 45 ° or less. Here, the angle θ means an inferior angle. In the present embodiment, the angle θ is 30 °. The above-mentioned distance W is determined as follows.

  FIG. 8 is a diagram for explaining the propagation of light in the living tissue, and shows a cross-sectional view along the depth direction. The light emitted from a certain light emitting unit L is diffusely reflected in the living tissue and reaches the light receiving unit S where a part of the irradiated light is present. The light propagation path has a so-called banana shape (a region sandwiched between two arcs), the width in the depth direction is the largest near the center, and the distance between the light-emitting element 53 and the light-receiving element 59. Accordingly, the entire depth (reachable depth) increases.

  In order to increase the measurement accuracy, it is desirable that a larger amount of transmitted light transmitted through the blood vessel 4 is received by the light receiving unit S. From this, it is preferable that the target blood vessel 4 is located below the light emitting portion L and the light receiving portion S, and a predetermined distance W corresponding to the assumed depth D of the target blood vessel 4 is determined. The predetermined distance W, that is, the optimum distance W between the light emitting part L and the light receiving part S is set to a distance approximately twice the depth D from the skin surface of the blood vessel 4. For example, when the depth D is about 3 mm, the optimum distance W is about 5 to 6 mm. Next, the relationship between the light emitting portion L and the light emitting element 53 and the relationship between the light receiving portion S and the light receiving element 59 will be described.

  FIG. 9 is a diagram illustrating a relationship between the light emitting unit L and the light emitting element 53 and a relationship between the light receiving unit S and the light receiving element 59. The light emitting portion L in the present embodiment is formed from a plurality of light emitting elements 53 in the light emitting region R1. The light emitting region R1 is a partial region of the light receiving and emitting regions of the sensor module 50 and refers to a region having a certain shape and size. In the present embodiment, the light emitting region R1 is a region in which three light emitting elements 53 enter in the vertical direction (Ys direction) and three light emitting elements 53 enter in the horizontal direction (Xs direction), and all the light emitting elements in the light emitting region R1 53 is caused to emit light as the light emitting portion L. In the present embodiment, the sensor module 50 includes more than three light emitting elements 53 in the vertical direction (Ys direction) and more than three light emitting elements 53 in the horizontal direction (Xs direction). For this reason, a plurality of light emitting portions L exist in the light receiving / emitting region of the sensor module 50. Then, the measurement light emitting portion Ld is selected from the plurality of light emitting portions L. A region including a plurality of light emitting elements 53 that emit light as the measurement light emitting portion Ld is also referred to as a first light emitting region. The first light emitting region constituting the measurement light emitting part Ld is preferably entirely outside the blood vessel.

  Note that the light emitting region having a certain shape and size may be, for example, a region for one light emitting element. In this case, one light emitting element 53 in this region becomes the light emitting portion L. Further, it is not necessary to cause all the light emitting elements 53 in the light emitting region R1 to emit light.

  Similarly, the light receiving portion S in the present embodiment is formed from a plurality of light receiving elements 59 in the light receiving region R2. The light receiving region R2 is a partial region of the light receiving and emitting regions of the sensor module 50 and refers to a region having a certain shape and size. In the present embodiment, the light receiving region R2 is a region in which three light receiving elements 59 enter in the vertical direction (Ys direction) and three light receiving elements 59 enter in the horizontal direction (Xs direction), and all the light receiving elements in the light receiving region R2 59 is received as the light receiving portion S. In the present embodiment, the sensor module 50 includes more than three light receiving elements 59 in the vertical direction (Ys direction) and more than three light receiving elements 59 in the horizontal direction (Xs direction). For this reason, a plurality of light receiving portions S exist in the light receiving / emitting region of the sensor module 50. Then, the measurement light receiver Sd or the reference light receiver Sr is selected from the plurality of light receivers S. A region including a plurality of light receiving elements 59 that receive light as the measurement light receiving unit Sd is also referred to as a first light receiving region, and a region including a plurality of light receiving elements 59 that emit light as the reference light receiving unit Sr is also referred to as a second light receiving region. The first light receiving region constituting the measurement light receiving portion Sd is preferably entirely outside the blood vessel. Similarly, the second light receiving region constituting the reference light receiving unit Sr is preferably entirely outside the blood vessel.

  For example, the light receiving region R2 having a certain shape and size may be a region corresponding to one light receiving element 59. In this case, one light receiving element 59 in the light receiving region R2 serves as the light receiving unit S. Moreover, it is not necessary to receive all the light receiving elements 59 in the light receiving region R2.

(A-4) Measurement When the measurement light emitting part Ld, the measurement light receiving part Sd, and the reference light receiving part Sr for the blood vessel part 6 to be measured are selected, the blood glucose level is measured. Specifically, the measurement light emitting unit Ld emits light, and (i) a light reception result Q1 of the light from the measurement light receiving unit Sd (referred to as “first light reception result Q1”), and (ii) the light of the light A light reception result Q2 (referred to as “second light reception result Q2”) from the reference light receiving unit Sr is acquired. Then, an absorption spectrum is generated using the light reception result Q1 and the light reception result Q2.

  At this time, for example, by changing the wavelength of the light emitted by the light emitting portion L, the wavelength λ of the light irradiated onto the skin surface is changed in the near infrared region, and the transmittance of the blood vessel part 6 for each wavelength λ is obtained. The transmittance T (λ) is calculated from the light intensity Os (λ) obtained by the measurement light-receiving unit Sd and the light intensity Or (λ) obtained by the reference light-receiving unit Sr by T (λ) = Os ( λ) / Or (λ). Then, an absorbance is obtained from the transmittance to generate an absorption spectrum.

  Here, the principle of calculating transmittance will be briefly described. In general, assuming that the intensity of light emitted from the light emitting portion L is P (λ), the transmittance of the object part through which the irradiated light is transmitted is T (λ), and the sensitivity defined for the light receiving portion S is S (λ). The light intensity O (λ) obtained by the light receiving unit S is given by O (λ) = P (λ) · T (λ) · S (λ).

  From this relational expression, the light intensity Or (λ) obtained by the reference light receiving unit Sr that does not include the transmitted light of the blood vessel 4 assumes that the transmittance T (λ) of the non-blood vessel region portion is “1”. λ) = P (λ) · S (λ).

  The light intensity Os (λ) obtained by the measurement light receiving unit Sd including the light transmitted through the blood vessel 4 is Os (λ) = P (λ) · T (λ) · S (λ). From these two equations, the transmittance T (λ) is obtained. Further, this transmittance T (λ) is a relative value with respect to the transmittance of the non-blood vessel region 8.

(A-5) Calculation of blood glucose level Subsequently, based on the absorption spectrum, the blood glucose level is estimated and calculated using a calibration curve showing the relationship between a predetermined blood glucose level (glucose concentration in blood) and absorbance. . In addition, the technique itself which calculates the density | concentration of a predetermined component (in this embodiment glucose) from this light absorption spectrum is well-known, and this well-known technique is applicable in this embodiment.

A3. Functional configuration:
FIG. 10 is a functional configuration diagram of the blood sugar level measuring apparatus 10 in the present embodiment. The blood glucose level measuring apparatus 10 functionally includes an operation input unit 110, a display unit 120, a sound output unit 130, a communication unit 140, an irradiation unit 210, an imaging unit 220, a control unit 300, and a storage. Unit 400.

  The operation input unit 110 is an input device such as a button switch, a touch panel, or various sensors, and outputs an operation signal corresponding to the performed operation to the control unit 300. The operation input unit 110 inputs various instructions such as a blood sugar level measurement start instruction. In FIG. 1, the operation switch 18 and the touch panel 16 correspond to this.

  The display unit 120 is a display device such as an LCD (Liquid Crystal Display), and performs various displays based on display signals from the control unit 300. Measurement results and the like are displayed on the display unit 120. In FIG. 1, the touch panel 16 corresponds to this.

  The sound output unit 130 is a sound output device such as a speaker and outputs various sounds based on the sound signal from the control unit 300. The sound output unit 130 outputs a notification sound such as the start or end of blood sugar level measurement or the occurrence of a low blood sugar level.

  The communication unit 140 is a communication device such as a wireless communication device, a modem, a cable communication cable jack or a control circuit, and is connected to a communication line to realize communication with the outside. In FIG. 1, the communication device 20 corresponds to this.

  The irradiation unit 210 includes a large number of light emitting elements 53 that are two-dimensionally arranged in a planar shape. The light emitting layer 52 of the sensor module 50 shown in FIG. The arrangement position of the irradiation unit 210 (specifically, the position coordinates of each light emitting element 53 in the Xs-Ys orthogonal coordinate system) is stored as a light emitting element list 406.

  The imaging unit 220 includes a large number of light receiving elements 59 that are two-dimensionally arranged in a planar shape. The light receiving layer 58 of the sensor module 50 shown in FIG. 2 corresponds to this. The arrangement position of the imaging unit 220 (specifically, the position coordinates of each light receiving element 59 in the Xs-Yx orthogonal coordinate system) is stored as a light receiving element list 408.

  The control unit 300 is realized by, for example, a microprocessor such as a CPU or a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), an electronic component such as an IC memory, a predetermined program or data, Various arithmetic processes are executed based on the operation signal from the operation input unit 110 to control the operation of the blood sugar level measuring apparatus 10. In FIG. 1, the control board 30 corresponds to this. The control unit 300 includes a blood glucose level measurement unit 310, an irradiation control unit 342, and an imaging control unit 344. The irradiation control unit 342 selectively controls the light emission of each of the plurality of light emitting elements 53. The imaging control unit 344 acquires the amount of light received from each of the plurality of light receiving elements 59.

  The blood glucose level measurement unit 310 includes a biological image acquisition unit 314, a blood vessel pattern acquisition unit 316, a blood vessel site selection unit 318, a light emitting / receiving unit selection unit 320, an absorption spectrum calculation unit 324, and a component value calculation unit 326. And measuring the glucose concentration in the blood of the user 2, that is, the blood glucose level.

  The biological image acquisition unit 314 acquires a biological image of the user 2. Acquisition of a biometric image is realized by appropriately using a biometric image capturing technique such as a known vein authentication technique. That is, the light emitting elements 53 emit light all at once, and photometry (photographing) is performed by all the light receiving elements 59. Then, a luminance image based on the photometric result, that is, a biological image is generated. The biological image acquired by the biological image acquisition unit 314 is stored as biological image data 414.

  The blood vessel pattern acquisition unit 316 performs predetermined image processing on the biological image acquired by the biological image acquisition unit 314 to acquire a blood vessel pattern. Specifically, it is realized by appropriately using a technique for identifying a vein pattern from a biological image in a known vein authentication technique. For example, binarization and filter processing are performed for each pixel of the biological image in comparison with the reference luminance. Pixels below the reference brightness indicate blood vessels, and pixels above the reference brightness indicate non-blood vessel regions. The blood vessel pattern acquired by the blood vessel pattern acquisition unit 316 is stored as blood vessel pattern data 416.

  Based on the blood vessel pattern acquired by the blood vessel pattern acquisition unit 316, the blood vessel region selection unit 318 selects the blood vessel region 6 indicating a predetermined selection condition as a measurement target. Here, the blood vessel part 6 to be measured may be one or plural. Each vascular site 6 selected as a measurement target is stored as vascular site data 418.

  FIG. 11 is a diagram illustrating an example of a data configuration of the blood vessel region data 418. As illustrated in FIG. The blood vessel part data 418 includes a blood vessel part ID 418a which is identification information of the blood vessel part, a part pixel list 418b, center line position information 418c, a part length 418d which is a length in the blood vessel longitudinal direction, and measurement light emitting unit data. 418e, measurement light receiving portion data 418f, and reference light receiving portion data 418g are stored. The part pixel list 418b is a list of pixels (that is, the light receiving elements 59) corresponding to the blood vessel part. The center line position information 418c is information on the position coordinates of the center line (the center in the blood vessel width direction and the line in the blood vessel length direction) of the blood vessel part in the Xs-Ys orthogonal coordinate system.

  The light receiving / emitting unit selection unit 320 selects the measurement light emitting unit Ld, the measurement light receiving unit Sd, and the reference light receiving unit Sr that satisfy the above-described conditions for each of the blood vessel parts 6 to be measured. The selected measurement light-emitting unit Ld is stored as measurement light-emitting unit data 418e. Similarly, the selected measurement light-receiving unit Sd is stored as measurement light-receiving unit data 418f, and the selected reference light-receiving unit. Sr is stored as reference light receiving unit data 418h. Note that when there is no measurement light-emitting part Ld, measurement light-receiving part Sd, and reference light-receiving part Sr that satisfy the above-described conditions, the angle θ formed by the first line segment N1 and the second line segment N2 After that, the measurement light emitting part Ld, the measurement light receiving part Sd, and the reference light receiving part Sr that satisfy the above-described conditions are similarly searched and selected. Similarly, when there is no measurement light-emitting part Ld, measurement light-receiving part Sd, and reference light-receiving part Sr that still satisfy the above-described conditions, the light emission for measurement that similarly satisfies the above-mentioned conditions after the angle θ is further reduced. The part Ld, the measurement light receiving part Sd, and the reference light receiving part Sr are searched and selected.

The absorption spectrum calculation unit 324 generates an absorption spectrum for each blood vessel part 6 to be measured. Specifically, by calculating the transmittance T for each wavelength λ based on the first light reception result Q1 from the measurement light receiver Sd and the second light reception result Q2 from the reference light receiver Sr, Generate an absorption spectrum. Further, when there are a plurality of blood vessel parts 6 to be measured, an average absorption spectrum is calculated by averaging the absorption spectra of the plurality of blood vessel parts 6 to be measured. The absorption spectrum calculated by the absorption spectrum calculation unit 324 is stored as the absorption spectrum data 420.

  The component value calculation unit 326 calculates a glucose concentration (that is, a blood glucose level) that is a blood concentration of a target blood component based on the absorption spectrum calculated by the absorption spectrum calculation unit 324. In this embodiment, an analytical method such as multiple regression analysis, principal component regression analysis, PLS regression analysis, or independent component analysis is used for the absorption spectrum. When there are a plurality of blood vessel parts 6 to be measured, the blood sugar level is calculated from the average absorption spectrum obtained by averaging the light absorption spectra of the blood vessel parts 6. The blood glucose level calculated by the component value calculation unit 326 is stored and stored as measured blood glucose level data 422 in association with the measurement time.

  The storage unit 400 is a storage device such as a ROM, a RAM, or a hard disk. The storage unit 400 stores programs, data, and the like for the control unit 300 to control the blood glucose level measuring apparatus 10 in an integrated manner. It is used as an area and temporarily stores calculation results executed by the control unit 300, operation data from the operation input unit 110, and the like. In FIG. 1, the main memory and measurement data memory mounted on the control board 30 correspond to this. The storage unit 400 also includes a system program 402, a blood glucose level measurement program 404, a light emitting element list 406, a light receiving element list 408, optimum distance data 410, biological image data 414, blood vessel pattern data 416, Blood vessel part data 418, absorption spectrum data 420, and measured blood glucose level data 422 are stored.

A4. Biometric information acquisition method:
FIG. 12 is a flowchart for explaining the flow of blood sugar level measurement processing as a biological information acquisition method. This process is realized by the control unit 300 executing a process according to the blood sugar level measurement program 404.

  According to FIG. 12, the blood glucose level measurement unit 310 performs a measurement process for measuring the blood glucose level of the user. First, the biological image acquisition unit 314 of the blood glucose level measurement unit 310 sets the entire light emitting surface of the sensor module 50 (that is, the range including all the light emitting elements 53) as the light emitting range, and causes the light emitting elements 53 within the light emitting range to emit light. Thus, a biological image of the user is acquired (step P120). Subsequently, the blood vessel pattern acquisition unit 316 acquires a blood vessel pattern viewed from the skin surface based on the obtained biological image (step P130). As a result, if a blood vessel pattern cannot be obtained (step P140: NO), the process returns to step P120.

  If a blood vessel pattern is obtained (step P140: YES), the blood vessel part selection unit 318 selects a blood vessel part 6 to be measured that satisfies a predetermined selection condition based on the obtained blood vessel pattern (step P150). . Then, the light receiving / emitting unit selecting unit 320 selects the measurement light emitting unit Ld, the measurement light receiving unit Sd, and the reference light receiving unit Sr (step P160). Next, the measurement light emitting unit Ld is caused to emit light (step P170), the first light reception result Q1 is obtained by the selected measurement light reception unit Sd, and the second light reception result Q2 is obtained by the selected reference light reception unit Sr. Obtain (step P210).

  Next, the absorption spectrum calculation unit 324 generates an absorption spectrum for the blood vessel site 6 using the first light reception result Q1 and the second light reception result Q2 (step P220). Furthermore, when there are a plurality of blood vessel parts 6 to be measured, an absorption spectrum that is an average of the absorption spectra for each blood vessel part 6 is calculated.

  Thereafter, the component value calculation unit 326 calculates the glucose concentration in the blood, that is, the blood glucose level, based on the absorption spectrum (step P230). Then, the calculated blood glucose level is displayed on the display unit 120 and is stored in association with the measurement time (step P240). After waiting for the elapse of a predetermined waiting time (step P250), the process returns to step P120, and the next blood glucose level is measured in the same manner.

A5. Effect:
According to the above-described embodiment, the first line segment N1 connecting the measurement light emitting unit Ld and the measurement light receiving unit Sd passes over the blood vessel, and connects the measurement light emitting unit Ld and the reference light receiving unit Sr. The second line segment N2 does not pass over the blood vessel. Further, the angle formed by the first line segment N1 connecting the measurement light emitting part Ld and the measurement light receiving part Sd and the second line segment N2 connecting the measurement light emitting part Ld and the reference light receiving part Sr. θ is 45 ° or less. For this reason, the structure of the living body in the optical path in which the light emitted by the measurement light emitting section Ld travels to the measurement light receiving section is the structure of the living body and the blood vessel in the optical path in which the light emitted by the reference light emitting section travels to the reference light receiving section. Approximate at other points. As a result, according to the biological information acquisition apparatus of this embodiment, biological information related to blood vessels can be acquired with high accuracy.

  The structure of the living body in the optical path in which the light emitted from the measurement light emitting section Ld travels to the light receiving section for measurement, and the structure of the living body in the optical path in which the light emitted from the measurement light emitting section Ld travels to the reference light receiving section. From the viewpoint of reducing differences other than blood vessels, the angle θ is preferably 40 ° or less, more preferably 35 ° or less, and further preferably 30 ° or less. On the other hand, the influence of the blood vessel existing under the first line segment N1 connecting the measurement light emitting unit Ld and the measurement light receiving unit Sd on the second light reception result Q2 acquired by the reference light receiving unit Sr is reduced. From the viewpoint, the angle θ is preferably 5 ° or more, more preferably 10 ° or more, and further preferably 15 ° or more.

  In the biological information acquiring apparatus 10 of the present embodiment, the light emitting region R1 having a certain shape and size is selected as a partial region of the light emitting / receiving region, and a plurality of light emitting elements in the selected light emitting region R1. 53 is caused to emit light as the measurement light emitting portion Ld. Thus, the light emitting portion L in the present embodiment is formed from a plurality of light emitting elements 53. For this reason, compared with the case where one light emission part is formed with one light emitting element, the biological information acquisition apparatus 10 of this embodiment can obtain sufficient light emission intensity. As a result, according to the biological information acquisition apparatus 10 of the present embodiment, biological information can be acquired with high accuracy.

  Similarly, in the biological information acquisition apparatus 10 of the present embodiment, a light receiving region R2 having a certain shape and size is selected as a partial region of the light receiving / emitting region, and a plurality of light receiving regions in the selected light receiving region R2 are selected. The element 59 is caused to receive light as the measurement light-receiving unit Sd or the reference light-receiving unit Sr. Thus, the light receiving portion S in the present embodiment is formed of a plurality of light receiving elements 59. For this reason, compared with the case where one light-receiving part is formed with one light-receiving element, the biological information acquiring apparatus 10 of the present embodiment can obtain a sufficient amount of received light. As a result, according to the biological information acquisition apparatus 10 of the present embodiment, biological information can be acquired with high accuracy.

  Further, in the biological information acquisition apparatus 10 of the present embodiment, since one light emitting unit L is formed by a set of a plurality of smaller light emitting elements 53, the position of the light emitting unit L is in units of the pitch of the small light emitting elements 53. You can choose. For this reason, according to the biological information acquiring apparatus 10 of the present embodiment, the degree of freedom for selecting the light emitting unit L is improved.

  Similarly, in the biological information acquisition apparatus 10 of the present embodiment, since one light receiving unit S is formed by a set of a plurality of smaller light receiving elements 59, the position of the light receiving unit S is a unit of the pitch of the small light receiving elements 59. Can be selected. For this reason, according to the biological information acquisition apparatus 10 of this embodiment, the freedom degree which selects the light-receiving part S improves.

B. Second embodiment:
The second embodiment is different from the first embodiment in that the measurement light receiving unit Sd and the reference light receiving unit Sr are provided with N pairs (N is an integer of 2 or more). It is different, but otherwise it is the same.

  FIG. 13 is a diagram illustrating selection of the light emitting unit L and the light receiving unit S of the second embodiment. Similarly to the first embodiment, also in this embodiment, the light emitting portion L that is separated from the blood vessel by the distance X (first distance) is selected as the measurement light emitting portion Ld.

  In the present embodiment, N pairs (N is an integer of 2 or more) of the measurement light-receiving units Sd and the reference light-receiving unit Sr are used. In the example of FIG. 13, N = 2. Of each of the N pairs of measurement light receivers Sd and reference light receivers Sr, each pair of measurement light receivers Sd and reference light receivers Sr is selected so that the following conditions are satisfied.

(1) First pair of light receiving portions Sd (1), Sr (1)
The light receiving part S separated from the measurement light emitting part Ld by a distance W (second distance) larger than the distance X is selected as the measurement light receiving part Sd (1), and is separated from the measurement light emitting part Ld by the distance W. The light receiving unit S is selected as the reference light receiving unit Sr (1).
(2) A second pair of light receiving portions Sd (2), Sr (2)
The light receiving part S separated by the distance W from the measurement light emitting part Ld is selected as the measurement light receiving part Sd (2), and the light receiving part S separated by the distance W from the measurement light emitting part Ld is selected as the reference light receiving part Sr ( Select as 2). The same applies when N is 3 or more.

  Note that the first set of light receiving units for measurement Sd (1) and the second set of light receiving units for measurement Sd (2) are different light receiving units, and the first set of reference light receiving units Sr (1) and two sets. It is a light receiving unit different from the reference light receiving unit Sr (2) of the eye. That is, the N light receiving units for measurement are different light receiving units, and the N reference light receiving units are different light receiving units.

  Further, the first line segment N1 (1) connecting the measurement light emitting unit Ld and the first set of light receiving units Sd (1) passes over the blood vessel, and the measurement light emitting unit Ld and the first set of light receiving units Sd (1). The second line segment N2 (1) connecting the reference light receiving unit Sr (1) does not pass over the blood vessel. Similarly, a first line segment N1 (2) connecting the measurement light emitting unit Ld and the second set of light receiving units Sd (2) passes over the blood vessel, and the measurement light emitting unit Ld and the second set. The second line segment N2 (2) connecting the reference light receiving portion Sr (2) does not pass over the blood vessel. The same applies when N is 3 or more.

  An angle θ (1) between the first line segment N1 (1) and the second line segment N2 (1) related to the first set of light receiving portions Sd (1) and Sr (1), and The angle θ (2) formed by the first line segment N1 (2) and the second line segment N2 (2) for the second set of light receiving portions Sd (2) and Sr (2) is 45 °, respectively. It is as follows. Here, both the angles θ (1) and θ (2) mean an inferior angle. In the present embodiment, the angle θ (1) and the angle θ (2) are each 30 °. The same applies when N is 3 or more.

  When the measurement light emitting section Ld that satisfies the above-described conditions and the N pairs of light receiving sections Sd and Sr do not exist, after the angle θ is further reduced, the measurement light emitting section Ld that satisfies the above-described conditions and the N pairs of light receiving sections Search and select the light receiving portions Sd and Sr.

  FIG. 14 is a flowchart for explaining the flow of blood sugar level measurement processing according to the second embodiment. Compared with the blood glucose level measurement process of the first embodiment, the blood glucose level measurement process of the second embodiment is (i) the light emitting / receiving unit selection unit 320 includes the measurement light emitting unit Ld, the measurement light receiving unit Sd, and the reference light receiving unit. Selecting part Sr (step P160A), (ii) obtaining a light reception result (step P210A), (iii) generating a spectrum (step P220A), and (iv) calculating a blood glucose level (Step P230A) is different, but is otherwise the same. Note that the process of acquiring the light reception result is also referred to as light reception processing.

  In the method of selecting the measurement light emitting unit Ld, the measurement light receiving unit Sd, and the reference light receiving unit Sr, as described above, a process of acquiring a light reception result (step P210A) and a process of generating a spectrum (step P220A) are described below. ) And the step of calculating the blood glucose level (step P230A) will be described.

  In the light reception process (step P210A), the control unit 300 acquires N light reception results from N pairs of light reception units Sd and Sr, respectively, thereby obtaining N sets of light reception results {Q1 (i), Q2 (i)} (i = 1 to N). Here, Q1 (i) is the first light reception result obtained from the i-th measurement light-receiving unit Sd (i), and Q2 (i) is obtained from the i-th reference light-receiving unit Sr (i). This is a second light reception result.

Then, in the process of generating the spectrum (step P220A), the control unit 300 uses the first light reception result Q1 (i) and the second light reception result Q2 (i) of each group to absorb the absorbance spectrum A of each group. _i (λ) is generated.
A _i (λ) = − log ₁₀ T _i (λ) (1)
T _i (λ) = Os _i (λ) / Or _i (λ) (2)
Here, T _i (λ) is the i-th transmittance spectrum obtained from the i-th light reception result, and Os _i (λ) is the light intensity spectrum obtained by the i-th measurement light-receiving unit Sd. Or _i (λ) is a light intensity spectrum obtained by the i-th reference light receiving portion Sr.

Next, in the step of calculating the blood sugar level (step P230A), the control unit 300 calculates the blood sugar level using the _N absorbance spectra A ₁ (λ) to A _N (λ). Specifically, the control unit 300 performs an averaging process on the _N absorbance spectra A ₁ (λ) to A _N (λ), and determines a predetermined blood sugar level based on the averaged absorbance spectrum Aave (λ). The blood sugar level is estimated and calculated using a calibration curve indicating the relationship between the value and the absorbance Aave (λs) at a specific wavelength λs.

  In the second embodiment, the first line segment N1 connecting the measurement light emitting unit Ld and the measurement light receiving unit Sd passes over the blood vessel. On the other hand, the second line segment N2 connecting the measurement light emitting portion Ld and the reference light receiving portion Sr does not pass over the blood vessel. The angle θ formed by the first line segment N1 and the second line segment N2 is 45 ° or less. For this reason, the structure of the living body in the optical path in which the light emitted from the measurement light emitting section Ld travels to the measurement light receiving section is the same as the structure of the living body in the optical path in which the light emitted from the measurement light emitting section Ld travels to the reference light receiving section. Approximate at points other than blood vessels. As a result, according to the biological information acquisition apparatus of this embodiment, biological information related to blood vessels can be acquired with high accuracy.

  In the second embodiment, since biological information is acquired using N sets (N = 2 in the second embodiment) of light reception results, biological information related to blood vessels can be acquired with high accuracy.

In the second embodiment, the absorbance spectra A _i (λ) of each set are generated using the first light reception result Q1 (i) and the second light reception result Q2 (i) of each set, and N sets The blood glucose level is calculated on the basis of the absorbance spectrum Aave (λ) obtained by averaging the absorbance spectra A ₁ (λ) to A _N (λ). However, the present invention is not limited to this.

For example, the absorbance spectrum A _t (λ) may be generated as follows.
_{A t (λ) = - log} 10 T t (λ) (3)
T _t (λ) = Os _t (λ) / Or _t (λ) (4)
Os _t (λ) = {Os ₁ (λ) +... + Os _N (λ)} / N (5)
Or _t (λ) = {Or ₁ (λ) +... + Or _N (λ)} / N (6)
Here, T _t (λ) is a transmittance spectrum obtained by combining N light reception results, and Os _t (λ) is obtained by averaging the light intensity spectra obtained by the N measurement light receiving portions Sd. Or _t (λ) is a light intensity spectrum obtained by averaging the light intensity spectra obtained by the N reference light receiving portions Sr.
That is, of the N sets of light reception results, the N first light reception results Os ₁ (λ) to Os _N (λ) are averaged to obtain a first averaged light reception result Os _t (λ). The N second light reception results Or ₁ (λ) to Or _N (λ) in the set light reception results are averaged to obtain a second averaged light reception result Or _t (λ), and the first average The absorbance spectrum A _t (λ) may be generated using the normalized light reception result Os _t (λ) and the second averaged light reception result Or _t (λ).

C. Variations:
The present invention is not limited to the above-described embodiments and modifications thereof, and can be carried out in various modes without departing from the gist thereof. For example, the following modifications are possible.

C1. Modification 1:
In the embodiment, after the selection of the measurement light emitting unit Ld, the measurement light receiving unit Sd, and the reference light receiving unit Sr) (step P160), the light emitting unit L emits light (step P170). However, the present invention is not limited to this. After the light emitting unit L emits light, the light receiving unit S may be selected.

C2. Modification 2:
In the said embodiment, a blood glucose level is acquired as biometric information. However, the present invention is not limited to this. As the biological information, for example, the oxygen saturation in the blood of the user who is the user may be acquired. The oxygen saturation in blood is the proportion of hemoglobin that is bound to oxygen out of hemoglobin in red blood cells. The hemoglobin in blood has different absorbances for red light and infrared light depending on the presence or absence of binding to oxygen. Therefore, for example, oxygen saturation is obtained by using a plurality of sets of elements having different emission wavelengths and light reception wavelengths, such as elements that emit or receive red light and elements that emit or receive infrared light. be able to.

  The present invention can also be applied in the following forms.

[Application Example 1]
A plurality of light emitting units for irradiating light to a living body;
A plurality of light receiving parts for receiving light transmitted through the living body;
A control unit that controls the plurality of light emitting units and the plurality of light receiving units,
The controller is
Identifying a position of a blood vessel of the living body by causing at least one of the plurality of light emitting portions to emit light,
Of the plurality of light emitting units, select a light emitting unit that is separated from the blood vessel by a first distance as a measurement light emitting unit, and emit light.
The light irradiated from the measurement light emitting unit is selected as the measurement light receiving unit, among the plurality of light receiving units, the light receiving unit separated from the measurement light emitting unit by a second distance larger than the first distance. To obtain the first light reception result,
The light received from the measurement light emitting unit is selected as a reference light receiving unit by selecting a light receiving unit that is separated from the measurement light emitting unit by the second distance from the plurality of light receiving units. Get
A biological information acquisition device that acquires biological information using the first light reception result and the second light reception result,
A first line segment connecting the measurement light emitting unit and the measurement light receiving unit passes over the blood vessel,
The second line connecting the measurement light emitting unit and the reference light receiving unit does not pass over the blood vessel,
The biological information acquisition apparatus, wherein an angle formed by the first line segment and the second line segment is 45 ° or less.

[Application Example 2]
A biological information acquisition apparatus according to Application Example 1,
In the light receiving and emitting region, each comprising a sensor module having a plurality of light emitting elements and a plurality of light receiving elements regularly arranged,
The control unit selects a light emitting region having a certain shape and size as a partial region of the light receiving and emitting region, and causes a plurality of light emitting elements in the light emitting region to emit light as the measurement light emitting unit. Acquisition device.

[Application Example 3]
The biological information acquisition device according to Application Example 1 or Application Example 2,
In the light receiving and emitting region, each comprising a sensor module having a plurality of light emitting elements and a plurality of light receiving elements regularly arranged,
The controller is
A first light receiving region and a second light receiving region having a certain shape and size are selected as a partial region of the light receiving / emitting region, and a plurality of light receiving elements in the first light receiving region are received as the measurement light receiving unit. And a biological information acquisition apparatus that receives a plurality of light receiving elements in the second light receiving region as the reference light receiving unit.

[Application Example 4]
The biological information acquisition device according to any one of Application Example 1 to Application Example 3,
The biological information acquisition apparatus, wherein the biological information includes a glucose concentration in blood of the biological body.

[Application Example 5]
The biological information acquisition device according to any one of Application Example 1 to Application Example 4,
The biological information acquisition apparatus, wherein the biological information includes oxygen saturation in blood of the living body.

[Application Example 6]
A biological information acquisition apparatus according to Application Example 1,
The controller is
The light receiving process for acquiring the first light receiving result and the second light receiving result is executed by selecting N pairs (N is an integer of 2 or more) of measurement light receiving units and reference light receiving units. N sets of a set of light reception results including the first light reception result and the second light reception result are acquired,
Using the N sets of light reception results, biometric information is acquired.
Biological information acquisition device.

[Application Example 7]
A biological information acquisition method for acquiring biological information by a biological information acquisition device comprising: a plurality of light emitting units that irradiate light to a living body; and a plurality of light receiving units that receive light transmitted through the living body.
Identifying the position of the blood vessel of the living body by causing at least one of the plurality of light emitting portions to emit light, and
A step of selecting a light emitting unit that is separated from the blood vessel by a first distance as the measurement light emitting unit among the plurality of light emitting units to emit light;
The light irradiated from the measurement light emitting unit is selected as the measurement light receiving unit, among the plurality of light receiving units, the light receiving unit separated from the measurement light emitting unit by a second distance larger than the first distance. And obtaining a first light reception result;
The light received from the measurement light emitting unit is selected as a reference light receiving unit by selecting a light receiving unit that is separated from the measurement light emitting unit by the second distance from the plurality of light receiving units. A process of obtaining
Using the first light reception result and the second light reception result to obtain biological information,
A first line segment connecting the measurement light emitting unit and the measurement light receiving unit passes over the blood vessel,
The second line connecting the measurement light emitting unit and the reference light receiving unit does not pass over the blood vessel,
The biological information acquisition method, wherein an angle formed by the first line segment and the second line segment is 45 ° or less.

[Application Example 8]
A biological information acquisition method according to Application Example 7,
The light receiving process for acquiring the first light receiving result and the second light receiving result is executed by selecting N pairs (N is an integer of 2 or more) of measurement light receiving units and reference light receiving units. Obtaining N sets of a set of light reception results including a first light reception result and the second light reception result;
A biological information acquisition method comprising: acquiring biological information using the N sets of light reception results.

  It should be noted that elements other than the elements described in the independent claims among the constituent elements in the above-described embodiments, application examples, and modification examples are additional elements and may be omitted as appropriate.

    DESCRIPTION OF SYMBOLS 1 ... Light emitting element, 2 ... User, 4 ... Target blood vessel, 5a ... Branching / merging part, 5b ... Image edge part, 6 ... Blood vessel part, 8 ... Non-blood vessel area | region, 10 ... Biometric information acquisition apparatus, 10A ... Biometric information Acquisition device, 12 ... body case, 14 ... fixed band, 16 ... touch panel, 18 ... operation switch, 20 ... communication device, 22 ... memory card, 24 ... reader / writer, 26 ... battery, 30 ... control board, 50 ... sensor module 52 ... Light emitting layer, 53 ... Light emitting element, 54 ... Light blocking layer, 56 ... Spectral layer, 58 ... Light receiving layer, 59 ... Light receiving element, 60 ... Light emitting range, 110 ... Operation input unit, 120 ... Display unit, 130 ... Sound Output unit 140 ... Communication unit 210 ... Irradiation unit 220 ... Imaging unit 300 ... Control unit 310 ... Blood glucose level measurement unit 314 ... Biological image acquisition unit 316 ... Blood vessel pattern acquisition unit 318 ... Blood vessel unit Selection unit 320 ... Light emitting / receiving unit selection unit 324 ... Absorption spectrum calculation unit 326 ... Component value calculation unit 342 ... Irradiation control unit 344 ... Imaging control unit 400 ... Storage unit 402 ... System program 404 ... Blood glucose Value measurement program, 406 ... Light emitting element list, 408 ... Light receiving element list, 410 ... Optimal distance data, 414 ... Biological image data, 416 ... Blood vessel pattern data, 418 ... Blood vessel part data, 418a ... Blood vessel part ID, 418b ... Part pixel List, 418c ... Center line position information, 418d ... Part length, 418e ... Measurement light-emitting part data, 418f ... Measurement light-receiving part data, 418g ... Reference light-receiving part data, 420 ... Absorption spectrum data, 422 ... Measured blood glucose level data , L: light emitting unit, Ld: light emitting unit for measurement, N1: first line segment, N2: second line segment O ... light intensity, Or ... light intensity, Os ... light intensity, P4 ... blood vessel pattern, Q1 ... first light reception result, Q2 ... second light reception result, R1 ... light emission region, R2 ... light reception region, S ... light reception unit , Sd: light receiving unit for measurement, Sr: light receiving unit for reference, T: transmittance, X: distance, W: distance, θ: angle

Claims (6)

A plurality of light emitting units for irradiating light to a living body;
A plurality of light receiving parts for receiving light transmitted through the living body;
A control unit that controls the plurality of light emitting units and the plurality of light receiving units;
A biological information acquisition device comprising:
The controller is
Identifying a position of a blood vessel of the living body by causing at least one of the plurality of light emitting portions to emit light,
Of the plurality of light emitting units, select a light emitting unit that is separated from the blood vessel by a first distance as a measurement light emitting unit, and emit light.
The light irradiated from the measurement light emitting unit is selected as the measurement light receiving unit, among the plurality of light receiving units, the light receiving unit separated from the measurement light emitting unit by a second distance larger than the first distance. A light receiving process for acquiring the first light receiving result and selecting the light receiving unit that is separated from the measurement light emitting unit by the second distance as the reference light receiving unit and acquiring the second light receiving result; A pair of light reception results constituted by the first light reception result and the second light reception result by selecting and executing a pair of measurement light reception units and a reference light reception unit (N is an integer of 2 or more) N sets,
Using the N sets of light reception results, biometric information is acquired,
Each of the N pairs of measurement light receivers and reference light receivers is a pair of measurement light receivers and reference light receivers.
(I) A first line segment connecting the measurement light emitting unit and the measurement light receiving unit passes over the blood vessel,
(Ii) The second line segment connecting the measurement light emitting unit and the reference light receiving unit does not pass over the blood vessel,
(Iii) The angle formed by the first line segment and the second line segment is 45 ° or less.
The biometric information acquisition device is selected so that the condition is established. The biological information acquisition apparatus according to claim 1,
In the light receiving and emitting region, each comprising a sensor module having a plurality of light emitting elements and a plurality of light receiving elements regularly arranged,
The control unit selects a light emitting region having a certain shape and size as a partial region of the light receiving and emitting region, and causes a plurality of light emitting elements in the light emitting region to emit light as the measurement light emitting unit. Acquisition device. The biometric information acquisition device according to claim 1 or 2,
In the light receiving and emitting region, each comprising a sensor module having a plurality of light emitting elements and a plurality of light receiving elements regularly arranged,
The controller is
A first light receiving region and a second light receiving region having a certain shape and size are selected as a partial region of the light receiving / emitting region, and a plurality of light receiving elements in the first light receiving region are received as the measurement light receiving unit. And a biological information acquisition apparatus that receives a plurality of light receiving elements in the second light receiving region as the reference light receiving unit. The biological information acquisition device according to any one of claims 1 to 3,
The biological information acquisition apparatus, wherein the biological information includes a glucose concentration in blood of the biological body. The biological information acquisition device according to any one of claims 1 to 4,
The biological information acquisition apparatus, wherein the biological information includes oxygen saturation in blood of the living body. A biological information acquisition method for acquiring biological information by a biological information acquisition device comprising: a plurality of light emitting units that irradiate light to a living body; and a plurality of light receiving units that receive light transmitted through the living body.
Identifying the position of the blood vessel of the living body by causing at least one of the plurality of light emitting portions to emit light, and
A step of selecting a light emitting unit that is separated from the blood vessel by a first distance as the measurement light emitting unit among the plurality of light emitting units to emit light;
The light irradiated from the measurement light emitting unit is selected as the measurement light receiving unit, among the plurality of light receiving units, the light receiving unit separated from the measurement light emitting unit by a second distance larger than the first distance. A light receiving process for acquiring the first light receiving result and selecting the light receiving unit that is separated from the measurement light emitting unit by the second distance as the reference light receiving unit and acquiring the second light receiving result; A pair of light reception results constituted by the first light reception result and the second light reception result by selecting and executing a pair of measurement light reception units and a reference light reception unit (N is an integer of 2 or more) Obtaining N sets of
Using the N sets of light reception results to obtain biological information,
Each of the N pairs of measurement light receivers and reference light receivers is a pair of measurement light receivers and reference light receivers.
(I) A first line segment connecting the measurement light emitting unit and the measurement light receiving unit passes over the blood vessel,
(Ii) The second line segment connecting the measurement light emitting unit and the reference light receiving unit does not pass over the blood vessel,
(Iii) The angle formed by the first line segment and the second line segment is 45 ° or less.
The biometric information acquisition method is selected so that the condition is satisfied.

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