Optical measurement device for biological information and method for measuring biological information

Abstract

To improve the resolution for acquiring biometric information. [Solution] A biometric information optical measuring device (1) comprising a control unit (100) that measures biometric information of a target part by deriving a first correction result obtained by correcting the first light-receiving result with the second light-receiving result and a third correction result obtained by correcting the third light-receiving result with the second light-receiving result, based on the first light-receiving result of a first light-receiving unit (12b) located a distance (L1) from the first light-emitting node (12-1), the second light-receiving result of a second light-receiving unit (13a) located a distance (L2) from the second light-receiving unit (13a) located a distance (L3) from the first light-emitting node (12-1).

Description

Technical Field

[0001] The present invention relates to an optical measurement device for biological information and a method for measuring biological information, which irradiate light toward a living body and receive the light propagated through a measurement target part in the living body to perform measurement.

Background Art

[0002] It is known that light is irradiated onto a living body and information is obtained non-invasively by utilizing the difference in the light absorption characteristics of dyes in the living body. For example, by utilizing the fact that hemoglobin in blood easily absorbs near-infrared light, changes in blood flow are measured, or the difference in color between oxygenated hemoglobin (hemoglobin to which oxygen is taken up and bound, bright red) and deoxygenated hemoglobin (hemoglobin not bound to oxygen, dark red) is utilized to measure the oxygen consumption in blood.

[0003] As technologies for acquiring biological information using light, the technologies described in Patent Documents 1 and 2 are known. In Patent Document 1 (Japanese Patent Application Laid-Open No. 2012-5556), an irradiation device and a light receiving device are arranged at three vertices of an equilateral triangle, only the light receiving device is arranged at the position of the centroid of the equilateral triangle, light is irradiated by one of the irradiation devices at the three vertices, a deep signal is acquired by the light receiving devices at the remaining two vertices, a correction signal is acquired by the light receiving device at the centroid position, and the deep signal is corrected by the correction signal. In Patent Document 1, it is possible to accurately extract deep information by correcting a deep signal including surface information and deep information with a correction signal including surface information.

[0004] In Patent Document 2 (International Publication No. 2020 / 174842), three probes are arranged at each vertex of an equilateral triangle, and an apparatus for measuring brain function by near-infrared spectroscopy by alternately performing light irradiation and detection from each probe is described. In Patent Document 2, the amount of light from each probe is adjusted in response to the difference in noise depending on the amount of hair.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2012-5556 [Patent Document 2] International Publication No. 2020 / 174842 (WO2020 / 174842A1) [Overview of the project] [Problems that the invention aims to solve]

[0006] (Problems with conventional technology) In the technologies described in Patent Documents 1 and 2, biological information is acquired at a position midway between the position of the light-emitting device and the position of the light-receiving device. Therefore, biological information can be acquired for each light-receiving device, and the resolution along the surface of the body is equal to the number of light-receiving devices (number per unit area, density). Furthermore, there is a problem in that it is not possible to shorten the distance between the light-emitting device and the light-receiving device in order to acquire biological information from deeper areas, making it difficult to increase the resolution.

[0007] The technical objective of this invention is to improve the resolution for acquiring biological information. [Means for solving the problem]

[0008] To solve the aforementioned technical problems, the optical measurement device for biological information according to claim 1 is: A first node having a first light source that emits measurement light toward a living organism and a first light receiving unit that receives the measurement light propagated through the part of the living organism to be measured, wherein a plurality of these first nodes are arranged along the surface of the living organism at predetermined intervals of a first distance, A second node having a second light-receiving unit that receives measurement light propagating through the surface layer of the living organism, wherein a plurality of second nodes are arranged at intervals of two or more adjacent first nodes by a second distance shorter than the first distance, A control unit that causes the first light source of any of the first nodes to emit light, the control unit measures biological information of the part to be measured by deriving a first correction result obtained by correcting the first light reception result with the second light reception result, and a third correction result obtained by correcting the third light reception result with the second light reception result, based on a first light reception result received by the first light receiving unit of the first node located at a distance of 1 from the first node where the first light source unit emitted light, a second light reception result received by the second light receiving unit of the second node located at a distance of 2 from the first node where the first light source unit emitted light, and a third correction result obtained by correcting the first light reception result with the second light reception result, It is characterized by having the following features.

[0009] The invention described in claim 2 is an optical measurement device for biological information described in claim 1, The first node, positioned at a location corresponding to the corner of an equilateral triangle, The second node is positioned at a location corresponding to the centroid of the equilateral triangle, It is characterized by having the following features.

[0010] The invention described in claim 3 is an optical measurement device for biological information described in claim 1, The first node is positioned at a location corresponding to the corner of the square, The second node is positioned at a location corresponding to the midpoint of each side of the square, It is characterized by having the following features.

[0011] To solve the aforementioned technical problems, the method for measuring biological information according to claim 4 of the invention is: A first node having a first light source that emits measurement light toward a living organism and a first light receiving unit that receives the measurement light propagated through the part of the living organism to be measured, wherein multiple first nodes are arranged along the surface of the living organism at predetermined intervals of a first distance, and a second node having a second light receiving unit that receives the measurement light propagated through the surface layer of the living organism, wherein multiple second nodes are arranged at intervals of a second distance shorter than the first distance between two or more adjacent first nodes, The first light source of any of the first nodes among the plurality of first nodes is made to emit light. The first light receiving result is obtained from the first light receiving unit of the first node located at a position separated by a distance of the first from the first node from which the first light source unit emitted light. The second light receiving result is obtained from the second light receiving unit of the second node, which is located at a position separated by a distance of 2 from the first node from which the first light source unit emitted light. The second light receiving unit of the second node, located at a position separated by a third distance that is longer than the second distance from the first node from which the first light source unit emitted light, receives a third light receiving result. A first correction result is obtained by correcting the first light reception result with the second light reception result, and a third correction result is obtained by correcting the third light reception result with the second light reception result, and the biological information of the measurement target is measured. It is characterized by the following: [Effects of the Invention]

[0012] According to the invention described in claims 1 and 4, the resolution for acquiring biological information can be improved compared to the conventional technique which does not utilize the third light reception result of the second node located at a third distance apart. According to the invention described in claim 2, by arranging the first node to correspond to the corners of an equilateral triangle that can tile a plane, and arranging the second node at the centroid position, it is possible to measure a wide area of ​​the surface of a living organism with minimal variations in density. According to the invention described in claim 3, by arranging the first nodes corresponding to the corners of the square that can be filled in a plane and arranging the second nodes at the intermediate positions of each side, it is possible to perform measurement in a state with less unevenness in density over a wide range of the surface of the living body.

Brief Description of the Drawings

[0013] [Figure 1] FIG. 1 is an overall explanatory view of Example 1 of the optical measurement device for biological information of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the main part of the optical measurement device for biological information in FIG. 1. [Figure 3] FIG. 3 is a plan view for explaining the positional relationship of each node of the optical measurement device for biological information in FIG. ¹. [Figure 4] FIG. 4 is an explanatory view of the outline of the optical measurement in Example 1. [Figure 5] FIG. 5 is an explanatory view of the optical measurement in Example 1. FIG. 5A is an explanatory view of an example where there is a change in blood volume in the vicinity of the light emitting part, FIG. 5B is an explanatory view of the measurement result of the measurement target part before correction, and FIG. 5C is an explanatory view of the measurement result of the measurement target part after correction. [Figure 6] FIG. 6 is a functional block diagram of the control unit of the optical measurement device in Example 1. [Figure 7] FIG. ³ is an explanatory view of the simulation result in the optical measurement device of Example 1. FIG. 7A is an explanatory view of the light emitting node and the light receiving node, FIG. 7B is an explanatory view of the light receiving result of the first node, FIG. 7C is an explanatory view of the light receiving result of the second node, and FIG. 7D is an explanatory view of the superposition result of FIG. 7B and FIG. 7C. [Figure 8] FIG. 8 is an explanatory view of Modification 1 corresponding to FIG. 3 of Example 1. FIG. 8A is an explanatory view of the positional relationship of each node, and FIG. 8B is an explanatory view of the signal estimation position in FIG. 8A. [Figure 9] FIG. 9 is an explanatory view of yet another Modification 2 of the modification shown in FIG. 8. FIG. 9A is an explanatory view of the positional relationship of each node, and FIG. 9B is an explanatory view of the signal estimation position in FIG. 9A. [Figure 10]Figure 10 is an explanatory diagram of yet another modification 3 of the modification shown in Figure 8, where Figure 10A is an explanatory diagram of the positional relationship of each node, and Figure 10B is an explanatory diagram of the signal estimation position in Figure 10A. [Modes for carrying out the invention]

[0014] Next, specific examples of embodiments of the present invention (hereinafter referred to as "examples") will be described with reference to the drawings, but the present invention is not limited to the following examples. In the following explanation using diagrams, diagrams of components other than those necessary for the explanation have been omitted as appropriate for ease of understanding. [Examples]

[0015] Figure 1 is an overall diagram illustrating Embodiment 1 of the optical measurement device for biological information according to the present invention. Figure 2 is a cross-sectional view of the main part of the optical measurement device for biological information shown in Figure 1. Figure 3 is a plan view illustrating the positional relationship of each node in the optical measurement device for biological information shown in Figure 1. In Figure 1, the cerebral blood flow measurement device, as an example of the optical measurement device 1 for biological information of the present invention, has a device body 2 that can be attached to the head of a subject. A personal computer 4, which is an example of an information processing device, is connected to the main unit 2 of the device via wiring 3. Therefore, the main unit 2 of the device and the personal computer 4 are capable of sending and receiving information and signals. In Embodiment 1, a configuration in which the personal computer 4 and the main unit 2 are connected by wire via wiring 3 is illustrated, but the invention is not limited to this, and it is also possible to send and receive information and signals by wireless communication or other means.

[0016] In Figures 1 to 3, the main body of the device 2 has a headgear section 11 as an example of a support section. The headgear section 11 supports an irradiation detection section 12 as an example of a first node and a correction detection section 13 as an example of a second node. The irradiation detection unit 12 includes a light-emitting unit 12a as an example of a first light source unit, and a first light sensor 12b as an example of a first light-receiving unit. The light-emitting unit 12a of Example 1 outputs near-infrared light (wavelength 700-1200 nm) as an example of light for measurement, which is in the wavelength range including 780 nm and 850 nm, where there is a difference in absorption spectra between oxygenated hemoglobin and deoxygenated hemoglobin. The wavelength range of the light can be arbitrarily changed according to the object to be measured (blood flow of the brain in Example 1), and it is also possible to use light in the visible light region, ultraviolet light region, or far-infrared light region, not just the near-infrared light exemplified. The correction detection unit 13 includes a second light sensor 13a as an example of a second light receiving unit.

[0017] In Figure 3, the irradiation detection units 12 of Example 1 are arranged at a predetermined distance L1 apart. For example, in Example 1, with the headgear unit 11 extended on a plane, the units are positioned at the three corners (vertices) of an equilateral triangle 21 that fills the surface of the headgear unit 11. Therefore, one side of the equilateral triangle 21 corresponds to the first distance L1. In Example 1, the first distance L1 is set to 30 mm as an example in order to capture blood flow in the brain (deep part of the head, cerebral cortex). However, to capture the blood volume in the cerebral cortex, the first distance L1 is preferably 25 mm to 40 mm. It is also possible to set it to 25 mm or less or 40 mm or more depending on the depth from the surface of the object to be measured.

[0018] Furthermore, the correction detection unit 13 is positioned at a distance of a second distance L2 that is shorter than the first distance L1 relative to the irradiation detection unit 12. As an example, in Embodiment 1, the correction detection unit 13 is positioned adjacent to each irradiation detection unit 12, specifically at a position corresponding to the centroid of the equilateral triangle 21. Therefore, the second distance L2 is the distance from the vertex of the equilateral triangle 21 to the centroid, and the second distance L2 is [1 / sqrt(3)] times (≒0.577) the length of one side of the equilateral triangle 21 (first distance L1). Thus, in Embodiment 1, L2 ≒0.577 × L1. Note that the second distance L2 can be changed according to the design and specifications, but to acquire surface signals, it is preferable to set the distance to 2 / 3 or less of the first distance L1.

[0019] In Figure 3, in Embodiment 1, light detection is performed at the correction detection unit 13(13-2), which is located at a third distance L3, longer than the second distance L2, relative to the irradiation detection unit 12 illuminated by the light-emitting unit 12a. In Embodiment 1, the third distance L3 is set to twice the second distance L2, i.e., L3 = 2 × L2 ≈ 1.15 × L1. Therefore, a correction detection unit 13(13-2) located one unit away from the light-emitting irradiation detection unit 12(12-1) corresponds to a correction detection unit 13(13-2) located at a third distance L3 from the light-emitting irradiation detection unit 12(12-1). In Example 1, the first distance L1 is set to 30 mm as an example, and the third distance L3 is 34.5 mm. The third distance L3 falls within the range of 25 mm to 40 mm, which is considered suitable for measuring blood flow in the cerebral cortex.

[0020] (Explanation of the overview of optical measurement) Figure 4 is an explanatory diagram illustrating the overview of the optical measurement in Example 1. Figure 5 is an explanatory diagram of the optical measurement in Example 1. Figure 5A is an explanatory diagram of an example in which a change in blood volume is present near the light-emitting part. Figure 5B is an explanatory diagram of the measurement results of the measurement target area before correction. Figure 5C is an explanatory diagram of the measurement results of the measurement target area after correction. In Figure 4, in the optical measuring device 1 of Example 1, light 31 (31-1 to 31-3) from the light-emitting unit 12a propagates within the body and then reaches the outside from the surface of the body via a path known as the banana shape. Therefore, the information of the body measured differs depending on the distance L1 to L3 from the light-emitting unit 12a of the optical sensors 12b and 13a. At a position a first distance L1 away from the light-emitting unit 12a, it is possible to measure blood flow 32 and changes in blood flow (high or low blood flow), thrombosis (extremely low or stagnant blood flow), etc., in the deep tissue (cerebral cortex) that is the target of measurement, from the measurement result of light 31-1. Strictly speaking, the position of the deep tissue that is measured is an intermediate position between the light-emitting unit 12a and the first optical sensor 12b (see the signal estimation position indicated by "×" in Figure 3).

[0021] At the second optical sensor 13a, located at a distance L2, light 31-2 that has propagated only to the surface and not to the deeper layers is observed. Therefore, it is possible to measure only the blood (blood pools 33, etc.) near the surface layer (scalp) directly below the light-emitting unit 12a. As shown in Figure 5B, the measurement result at the first distance L1 includes not only the blood flow in the deeper layers but also the blood in the surface layer directly below the light-emitting unit 12a. Therefore, by correcting the measurement result of the first optical sensor 12b at the first distance L1 with the result of the second optical sensor 13a at the second distance L2, it is possible to accurately measure only the blood flow in the deeper layers, as shown in Figure 5C.

[0022] In Example 1, not only the measurement result of the first optical sensor 12b, which is located at a distance of L1, but also the measurement result of light 31-3 from the second optical sensor 13a, which is located at a distance of L3, is used as the measurement result of deep blood flow. That is, the second optical sensor 13a uses the measurement result at a distance of L2 relative to the light-emitting irradiation detection unit 12 for correction, but the measurement result at a distance of L3 is used as the measurement result of the target of measurement (deep tissue). In this case, the deep tissue position measured is, strictly speaking, the position midway between the light-emitting unit 12a and the second optical sensor 13a at a distance of L3 (see the signal estimation position indicated by "□" in Figure 3).

[0023] (Description of the control unit in Example 1) Figure 6 is a functional block diagram of the control unit of the optical measuring device in Example 1. In Figure 6, the control unit 100 of the personal computer 4 in Embodiment 1 is composed of a computer device having an I / O (input / output interface) that performs input / output of signals to and from the outside and adjustment of input / output signal levels, a ROM (read-only memory) that stores programs and data for performing necessary startup processing, a RAM (random access memory) for temporarily storing necessary data and programs, a CPU (central processing unit) that performs processing according to the startup program stored in the ROM, etc., and a clock oscillator, etc. Various functions can be realized by executing the programs stored in the ROM and RAM, etc. The control unit 100 stores basic software that controls basic operations, so-called operating system OS, a measurement program P1 as an example of an application program, and other software not shown.

[0024] (Element connected to the control unit 100 in Example 1) The control unit 100 receives output signals from signal output elements such as a keyboard, mouse, and optical sensors 12b and 13a. Furthermore, the control unit 100 in Embodiment 1 outputs control signals to controlled elements such as the monitor and the light-emitting unit 12a.

[0025] (Functions of the control unit 100) The measurement program P1 of the control unit 100 in Example 1 has the following functional means (program modules) C1 to C5.

[0026] The light emission control means C1 controls the light emission by transmitting a control signal to the light emission unit 12a. The light emission control means C1 controls one of the three vertices of the equilateral triangle 21 light emission unit 12a to be lit for a predetermined time. Next, it lights up one of the remaining two vertices' light emission unit 12a for a predetermined time, and then lights up the remaining one light emission unit 12a for a predetermined time. In other words, it controls the multiple light emission units 12a to be lit one by one in a selective manner. Note that the number of light emission units 12a to be lit is not limited to one; it is also possible to light up multiple light emission units 12a that are sufficiently far apart from each other so as not to adversely affect the measurements by the light sensors 12b and 13a.

[0027] The deep tissue measurement means (target measurement means) C2 measures the light that propagates deep into the body from the light-emitting unit 12a. Specifically, it acquires measurement results from a first optical sensor 12b located at a first distance L1 away from the emitted light-emitting unit 12a, and from a second optical sensor 13a (13-2) located at a third distance L3 away. Therefore, the measurement result from the first optical sensor 12b becomes the first light reception result, and the measurement result from the second optical sensor 13a (13-2) at the third distance L3 becomes the third light reception result. The position of the measurement result on the head (the position where blood flow was measured) is measured at a position midway between the light-emitting unit 12a and the first optical sensor 12b (see the "×" position in Figure 3) and at a position midway between the light-emitting unit 12a and the second optical sensor 13a (13-2) at the third distance L3 (see the "□" position in Figure 3). The surface measurement means (correction measurement means) C3 measures the light that propagates from the light-emitting part 12a across the surface. Specifically, it acquires the measurement result of a second light sensor 13a(13-1) located at a second distance L2 from the emitted light-emitting part 12a. Therefore, the measurement result of the second light sensor 13a(13-1) at the second distance L2 becomes the second light reception result. The position of the surface measurement result on the head is measured as the position of the light-emitting part 12a.

[0028] The correction means C4 corrects the measurement results of the deep measurement means C2 with the measurement results of the surface measurement means C3. That is, it derives a first corrected result obtained by correcting the first light reception result with the second light reception result, and a third corrected result obtained by correcting the third light reception result with the second light reception result. Any correction method is possible, such as finding and removing the in-phase component of the second light reception result from the first and third light reception results, or weighting the second light reception result and subtracting it. Other correction methods are also possible, such as deriving and removing similar components of the first and third light reception results and the second light reception result by independent component analysis, or measuring each light reception result multiple times and taking the average. It should be noted that known technologies, such as the technology described in Patent Document 1, can also be used. The measurement result display means (result output means) C5 outputs the results corrected by the correction means C4 to the monitor of the personal computer 4 as measurement results of blood flow in the cerebral cortex of the head. At this time, it is possible to display the results in a map-like manner according to the measurement position of the deep measurement means C2. At this time, it is possible to display the measurement results of the first optical sensor 12b at the first distance L1 and the measurement results of the second optical sensor 13a at the third distance L3 overlaid on each other, or they can be displayed individually.

[0029] (Effect of Example 1) In the biometric information optical measurement device 1 of Embodiment 1, which has the above configuration, the light from the light-emitting unit 12a is measured by the first optical sensor 12b at a first distance L1, and corrected with the measurement result of the second optical sensor 13a at a second distance L2. In Embodiment 1, the measurement result of the second optical sensor 13a at a third distance L3 from the light-emitting unit 12a is also used as the measurement result of the object to be measured. In Patent Document 1, the information corresponding to the measurement result of the second optical sensor 13a was only used for correction. Therefore, in the technologies described in Patent Documents 1 and 2, the measurable positions and number were limited to the positions and number of the first optical sensor 12b. Furthermore, when attempting to measure depth, it was necessary to increase the distance between the irradiation detection units 12 beyond the first distance L1, which limited the density of the irradiation detection units 12 and made it difficult to increase the resolution (number of measurement positions per unit area). In contrast, in Example 1, by performing measurements with the second optical sensor 13a, which was previously only used for correction in the conventional technology, even at a third distance L3 away from the light-emitting irradiation detection unit 12, it became possible to increase the number of measurement results and measurement locations without adding any components to the configuration of Patent Document 1. In other words, the number of measurement locations per unit area can be increased, and the resolution for acquiring biological information can be improved.

[0030] In Example 1, the irradiation detection unit 12 is positioned at the corners of the equilateral triangle 21, and the correction detection unit 13 is positioned at the centroid of the equilateral triangle 21. The equilateral triangle 21 is arranged to tile the surface of the head. In arrangements other than tile-tile, there may be localized areas where measurements are not taken, or the density of measurements may vary. However, with the tile-tile arrangement, measurement results with less density can be obtained over a wide area of ​​the head.

[0031] (Simulation results) Figure 7 is an explanatory diagram of the simulation results using the optical measurement device in Example 1. Figure 7A is an explanatory diagram of the light-emitting node and the light-receiving node, Figure 7B is an explanatory diagram of the light-receiving result of the first node, Figure 7C is an explanatory diagram of the light-receiving result of the second node, and Figure 7D is an explanatory diagram of the superimposed result of Figures 7B and 7C. In Figure 7A, the simulation was performed assuming that positions 41-1 and 41-2, indicated by black circles, represent areas with large changes in blood flow. The method used for analysis in the simulation was based on "Mamiko Fujii, et al., 'Depth-Selective Diffuse Optical Imaging Using Sensitivity Adaptive Regularization,' Biomedical Engineering, Vol. 48, No. 4, pp. 385-395, 2010." Figure 7B shows the simulation results when measurement is performed using only the light reception results of the irradiation detection units 12 at the vertices of the equilateral triangle 21, as in the conventional technology. In Figure 7B, the first black circle 41-1, which is located midway between the irradiation detection units 12, can be measured with good accuracy, but the position of the second black circle 41-2 cannot be clearly measured. Figure 7C shows the simulation results when measured by the second optical sensor 13a (13-2) located at a third distance L3. In Figure 7C, the first black circle 41-1, which is located midway between the irradiation detection units 12 at the first distance L1, is not clearly measured, but the position of the second black circle 41-2, which corresponds to a position measurable by the second optical sensor 13a at a third distance L3, is measured with good accuracy. Therefore, as shown in Figure 7D, by superimposing the results of Figure 7B and Figure 7C, it became possible to accurately measure the position of the second black circle 41-2, which could not be measured accurately in the past, and it was confirmed that the measurement resolution and precision could be improved.

[0032] (modified version) Figure 8 is an explanatory diagram of Modification 1, which corresponds to Figure 3 of Example 1. Figure 8A is an explanatory diagram of the positional relationship of each node, and Figure 8B is an explanatory diagram of the signal estimation position in Figure 8A. In Example 1, the irradiation detection unit 12 is positioned at the three vertices of the equilateral triangle 21, and the correction detection unit 13 is positioned at the centroid of the equilateral triangle 21. However, the invention is not limited to this configuration. As shown in Figure 8A, it is also possible to position the irradiation detection unit 12' at the four vertices of the square 201, and the correction detection unit 13' at the midpoint of each side of the square 201. In this case, the first distance L1 is equal to the length of one side of the square 201, and the second distance L2 is half the length of the first distance L1. The third distance L3 is approximately 1.12 times the length of the first distance L1 [sqrt(5) / 2]. Therefore, the signal estimation position is obtained not only from the detection result of the first optical sensor 12b at the first distance L1 indicated by "×" in Figure 8B, but also from the detection result of the second optical sensor 13a at the third distance L3 indicated by "□" in Figure 8B. Therefore, in the embodiment shown in Figure 8, as in Example 1, it is possible to measure biological information (such as blood flow rate) while improving resolution by using a second optical sensor 13a' located at a third distance L3.

[0033] Figure 9 is an explanatory diagram of yet another modified example of the modified example shown in Figure 8, where Figure 9A is an explanatory diagram of the positional relationship of each node, and Figure 9B is an explanatory diagram of the signal estimation position in Figure 9A. Figure 10 is an explanatory diagram of yet another modification 3 of the modification shown in Figure 8, where Figure 10A is an explanatory diagram of the positional relationship of each node, and Figure 10B is an explanatory diagram of the signal estimation position in Figure 10A. By changing the second optical sensor 13a at a third distance L3, which acquires the light reception result when light is emitted, in relation to the arrangement of the square 201 shown in Figure 8, it becomes possible to change and adjust the position and number of signal estimation positions indicated by "□" as shown in Figures 9 and 10. Therefore, even in modified examples 1 to 3, it is possible to improve the resolution without increasing the number of second optical sensors 13a, which were conventionally used only for correction.

[0034] (Other examples of changes) Although embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the gist of the present invention as described in the claims. Examples of modifications to the present invention (H01) to (H03) are shown below. (H01) In the above embodiment, the control unit 100 is shown as a personal computer located at a location separate from the main body of the device 2, but it is not limited to this. It is also possible to miniaturize it using a microchip or integrated circuit and mount the control unit 100 on the main body of the device 2. Furthermore, although an example was given in which each of the means C1 to C5 of the control unit 100 is centrally processed by a personal computer 4, it is not limited to this. For example, it is also possible to distribute the processing of some or all of it using multiple network-connected information processing devices.

[0035] (H02) In the above embodiments, the specific numerical values ​​and other details exemplified can be arbitrarily changed according to the design and specifications. That is, in Embodiment 1, which measures blood flow in the cerebral cortex of the head, a first distance of 25 mm to 40 mm was exemplified as being preferable, but the distance can be changed to an appropriate distance depending on the depth of the object to be measured, or the wavelength band of light used can be changed according to the absorbance characteristics of the object to be measured. (H03) In the above embodiment, an example was given in which the irradiation detection units 12, 12' are arranged to correspond to the corners of an equilateral triangle or a square, but the embodiment is not limited thereto. It is also possible to arrange them to correspond to the corners of a tiling shape such as a regular hexagon, or to arrange them in a way that is not tiling. That is, if it is desired to acquire information on a specific position of a living organism, it is also possible to arrange the irradiation detection units 12, 12' and the correction detection units 13, 13' according to the specific position. [Explanation of symbols]

[0036] 1… Optical measurement device for biological information, 12,12′…the first node, 12a...First light source unit, 12b...First light receiving unit, 13,13′…Second node, 13a...Second light receiving unit, 21...Equilateral triangle, 100... Control unit, 201...square, L1... First distance, L2... Second distance, L3... The third distance.

Claims

1. A first node having a first light source that emits measurement light toward a living organism and a first light receiving unit that receives the measurement light propagated through the part of the living organism to be measured, wherein a plurality of these first nodes are arranged along the surface of the living organism at predetermined intervals of a first distance, A second node having a second light-receiving unit for receiving measurement light propagated through the surface layer of the living organism, wherein a plurality of second nodes are arranged at intervals of two or more adjacent first nodes by a second distance shorter than the first distance, A control unit that causes the first light source of any of the first nodes to emit light, the control unit measures biological information of the part to be measured by deriving a first correction result obtained by correcting the first light reception result with the second light reception result, and a third correction result obtained by correcting the third light reception result with the second light reception result, based on a first light reception result received by the first light receiving unit of the first node located at a distance of first distance from the first node where the first light source unit emitted light, a second light reception result received by the second light receiving unit of the second node located at a distance of third distance, which is longer than the second distance from the first node where the first light source unit emitted light, and A biometric optical measurement device characterized by having the following features.

2. The first node, positioned at a location corresponding to the corner of an equilateral triangle, The second node is positioned at a location corresponding to the centroid of the equilateral triangle, The optical measurement device for biological information according to claim 1, characterized by comprising the above.

3. The first node is positioned at a location corresponding to the corner of the square, The second node is positioned at a location corresponding to the midpoint of each side of the square, The optical measurement device for biological information according to claim 1, characterized by comprising the above.

4. A first node having a first light source that emits measurement light toward a living organism and a first light receiving unit that receives the measurement light propagated through the part of the living organism to be measured, wherein multiple first nodes are arranged along the surface of the living organism at predetermined intervals of a first distance, and a second node having a second light receiving unit that receives the measurement light propagated through the surface layer of the living organism, wherein multiple second nodes are arranged at intervals of a second distance shorter than the first distance between two or more adjacent first nodes, The first light source of any of the first nodes among the plurality of first nodes is made to emit light. The first light receiving result is obtained from the first light receiving unit of the first node located at a position separated by a first distance from the first node from which the first light source unit emitted light. The second light receiving result is obtained from the second light receiving unit of the second node located at a position separated by a second distance from the first node from which the first light source unit emitted light. The second light receiving unit of the second node, located at a position separated by a third distance that is longer than the second distance from the first node from which the first light source unit emitted light, receives a third light receiving result. A first correction result is obtained by correcting the first light reception result with the second light reception result, and a third correction result is obtained by correcting the third light reception result with the second light reception result, and the biological information of the measurement target is measured. A method for measuring biological information characterized by the following features.

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