WO2022172533A1

WO2022172533A1 - Light detection unit and brain function measuring apparatus using same

Info

Publication number: WO2022172533A1
Application number: PCT/JP2021/040945
Authority: WO
Inventors: 隆佐々木
Original assignee: 株式会社島津製作所
Priority date: 2021-02-09
Filing date: 2021-11-08
Publication date: 2022-08-18
Also published as: JPWO2022172533A1; CN116709984A

Abstract

A light detection unit (23) is provided with: a light detector (31) for detecting light; a cylindrical storage container (71) for storing the light detector (31); and a flexible substrate (73) having a signal processing circuit mounted thereon, the signal processing circuit including an A/D converter (33) for converting an optical signal detected by the light detector (31) from an analog signal to a digital signal. The flexible substrate (73) is placed within the storage container (71) in a bent and deformed state.

Description

Optical detection unit and brain function measuring device using the same

The present invention relates to a photodetection unit and a brain function measurement device using the same, and more particularly to a brain function measurement device provided with a photodetection unit arranged on the head of a subject.

Conventionally, there is known a brain function measuring device that observes the state of brain activity by irradiating the subject's head with light (for example, Patent Document 1). Such a brain function measuring device includes a measuring unit attached to the head of a subject, and a main unit connected to the measuring unit via an optical fiber.

The measurement unit includes a light irradiation unit that irradiates the subject's brain with near-infrared light of multiple wavelengths, and a light-receiving unit that receives the near-infrared light emitted from the brain after passing through the brain. By comparing the intensity of the light emitted by the light irradiation unit and the intensity of the light detected by the light detection unit and measuring the intensity change of the light, the cerebral blood flow activity can be measured.

The main unit includes a light source, such as a light-emitting diode, a light detection unit, and a main control section that controls each component. The photodetection unit includes a photodetector for detecting light, an amplifier for amplifying the detected optical signal, and an A/D converter for converting the amplified optical signal into a digital signal. Typically, amplifiers and A/D converters are mounted on printed circuit boards.

The light source is connected via an optical fiber to a light irradiation mechanism such as a light transmitting probe, and the photodetector is connected via an optical fiber to a light receiving unit. That is, the near-infrared light emitted from the light source is sent to the measurement unit side via the optical fiber, and is irradiated to the subject's brain from the light irradiation mechanism. Near-infrared light emitted from the subject's brain is received by a light receiving unit provided in the measurement unit, and the received near-infrared light is sent to the main unit side via an optical fiber. The near-infrared light sent to the main unit side is detected by the photodetector. That is, an optical signal is amplified by an amplifier on a printed circuit board and then converted from an analog signal to a digital signal by an A/D converter. Information on brain activity can be obtained by analyzing the digitally converted optical signal.

JP 2017-080479 A

However, the conventional example having such a configuration has the following problems.

In the conventional configuration, after the light received by the measurement unit side is transmitted to the main unit side, amplification processing and digital conversion processing are performed on the optical signal, which is an analog signal. Therefore, light reduction occurs during transmission to the main unit side. Since the noise ratio increases as the intensity of the optical signal decreases, there is a concern that the S/N ratio (signal-to-noise ratio) will decrease as a result. In addition, since an optical fiber with a length of several meters is required to transmit light from the measurement unit to the main unit, the cost is increased. Also, since optical fibers are less durable than general cables, it is necessary to handle brain function measuring devices with care.

The present invention has been made in view of such circumstances, and an object thereof is to provide a photodetection unit capable of improving the S/N ratio of an optical signal and a brain function measuring device provided with the same.

In order to achieve these objects, the present invention has the following configuration.
That is, the photodetection unit according to the present invention includes a photodetector for detecting light, a cylindrical housing container for housing the photodetector, and an optical signal detected by the photodetector for converting from an analog signal to a digital signal. a flexible substrate on which a signal processing circuit including an A/D converter for conversion is mounted, and the flexible substrate is arranged inside the container in a state of being bent and deformed.

In this configuration, since the signal processing circuit including the A/D converter is mounted on the flexible substrate, the flexible substrate can be bent and deformed to have a smaller shape. Both the photodetector and the A/D converter are arranged inside the housing container by placing the flexible substrate in a bent state inside the housing container. That is, since the photodetector and the A/D converter can be arranged closer to each other, the optical signal detected by the photodetector can be quickly converted from an analog signal to a digital signal. Therefore, since it is possible to avoid a decrease in optical signal intensity due to transmission of the optical signal in the form of an analog signal, it is possible to improve the S/N ratio of the optical signal while downsizing the photodetector unit.

In the above-described invention, the flexible substrate includes a first portion connected to the photodetector, a second portion mounted with a signal processing circuit including the A/D converter, and the first portion. a connecting portion that connects the second portion to the flexible substrate by bending the connecting portion so that the first portion and the second portion are perpendicular to each other and bending and deforming the second portion; It is preferable that the container is deformed into a cylindrical shape along the inner surface of the container.

[Action and Effect] According to the photodetector unit of the present invention, the connecting portion that connects the first portion and the second portion constituting the flexible substrate is bent, and the second portion is bent and deformed so that the flexible substrate is bent. can be deformed into a cylindrical shape along the inner surface of the container. Therefore, the flat flexible substrate can be deformed into a smaller cylindrical shape. Further, with such a configuration, due to the restoring force that causes the second part to return to its original shape, the flexible substrate exerts a pressing force on the inner surface of the container. Since the flexible substrate is held inside the container by the pressing force, the flexible substrate can be stably held inside the container without using fixing tools such as screws.

In the above-described invention, the flexible substrate includes a first portion connected to the photodetector, a second portion mounted with a signal processing circuit including the A/D converter, and the first portion. a connecting part for connecting the second part, wherein the flexible substrate is folded inside the container by bending the connecting part so that the first part and the second part overlap each other. is preferably transformed into

[Action and Effect] According to the photodetection unit of the present invention, the first and second portions of the flexible substrate are overlapped by bending the connection portion that connects the first and second portions. , the flexible substrate can be transformed into a folded state inside the container. Therefore, the flat flexible substrate can be deformed into a smaller shape. Therefore, the volume occupied by the flexible substrate can be further reduced, so that the light detection unit can be further miniaturized.

Moreover, in order to achieve such an object, the present invention may adopt the following configuration.
That is, a brain function measuring apparatus according to the present invention has the above-described light detection unit and a light irradiation unit for irradiating light onto the brain of the subject, and the measurement unit is mounted on the head of the subject. and a main body electrically connected to the measurement unit and having a brain function measurement unit that acquires measurement data relating to brain activity of the subject based on the optical signal digitally converted by the A/D converter. and a unit.

[Action and Effect] According to the brain function measuring apparatus of the present invention, the board on which the A/D converter is mounted is a flexible board so that the board can be arranged inside the container provided with the photodetection unit. It can be bent and deformed. Therefore, the photodetection unit can be miniaturized, so that the photodetection unit can be arranged on the side of the measurement unit attached to the head of the subject, not on the side of the main unit.

With such a configuration, the light irradiated from the light irradiation unit and transmitted through the subject's brain is detected by the photodetector provided in the photodetection unit, and then quickly converted into a digital signal by the A/D converter. be. Therefore, it is possible to avoid reduction in optical signal intensity due to transmission of the optical signal in the form of an analog signal, thereby improving the S/N ratio of the optical signal. As a result, the accuracy of brain function measurement data can be further improved.

According to the photodetection unit and the brain function measuring device having the same according to the present invention, the signal processing circuit including the A/D converter is mounted on the flexible substrate. can be Both the photodetector and the A/D converter are arranged inside the housing container by placing the flexible substrate in a bent state inside the housing container. That is, since the photodetector and the A/D converter can be arranged closer to each other, the optical signal detected by the photodetector can be quickly converted from an analog signal to a digital signal. Therefore, since it is possible to avoid a reduction in optical signal intensity caused by transmitting the optical signal in the state of an analog signal, it is possible to improve the S/N ratio of the optical signal detected by the optical detection unit while downsizing the optical detection unit. be able to.

1 is a perspective view illustrating the overall configuration of a brain function measuring device according to Example 1. FIG. 1 is a functional block diagram illustrating the configuration of a brain function measuring device according to Example 1; FIG. FIG. 2 is a cross-sectional view showing the positional relationship between a pair of light-transmitting probe and light-receiving probe according to Example 1 and the measurement site of the brain. 4 is a cross-sectional view for explaining the configuration of the probe unit holder according to Example 1. FIG. 4 is a perspective view showing a state in which a cover member is attached to the main body of the probe unit according to the first embodiment; FIG. 4 is a perspective view showing a state in which a cover member is removed from the main body of the probe unit according to Example 1. FIG. FIG. 7 is a cross-sectional view along line AA in FIG. 6 in the main body of the probe unit according to Example 1; FIG. 4 is a perspective view illustrating the configuration of a holding member of the probe unit according to Example 1; FIG. 4 is a perspective view illustrating a state in which a holding member and a main body of the probe unit according to Example 1 are combined; 2 is a vertical cross-sectional view of a photodetection unit according to Example 1. FIG. 1 is a plan view of a flexible substrate according to Example 1. FIG. FIG. 4 is a perspective view showing a state in which a second portion of the flexible substrate according to Example 1 is erected; FIG. 5 is a perspective view showing a state in which a second portion of the flexible substrate according to Example 1 is curved into a tubular shape; 4 is a perspective view showing a state in which the photodetection unit according to the first embodiment is assembled; FIG. 2 is a vertical cross-sectional view of a photodetection unit according to Example 1. FIG. FIG. 10 is a plan view of a flexible substrate according to Example 2; FIG. 11 is a perspective view showing a state in which the second portion of the flexible substrate according to Example 2 is erected; FIG. 10 is a perspective view showing a state in which the second portion of the flexible substrate according to Example 2 is curved into a tubular shape; FIG. 10 is a vertical cross-sectional view of a photodetection unit according to Example 2; FIG. 11 is a plan view of a flexible substrate according to Example 3; FIG. 11 is a perspective view showing a state in which the flexible board according to Example 2 is deformed into a columnar shape as a whole by bending each connecting portion; FIG. 10 is a vertical cross-sectional view of a photodetection unit according to Example 3; FIG. 11 is a vertical cross-sectional view of a photodetector unit according to a modified example;

Embodiment 1 of the present invention will be described below with reference to the drawings.

<Explanation of overall configuration>
A brain function measuring device 1 according to Example 1 includes a measuring unit 3 and a main unit 5, as shown in FIG. The measuring unit 3 and the main unit 5 are electrically connected via a cable 6 . The measurement unit 3 is attached to the subject M's head. In this embodiment, a laptop computer is used as the main unit 5 .

The measurement unit 3 includes a probe unit 7 and a probe unit holder 8. The probe unit holder 8 holds the probe unit 7 . The probe unit holder 8 has a shape that covers the head of the subject M, and is made of a light-shielding material. As an example of a constituent material of the probe unit holder 8, resin having a helmet shape is given. By mounting the probe unit holder 8 on the head of the subject M, the probe unit 7 is held on the head of the subject M. As shown in FIG.

The position and number of the probe units 7 arranged in the probe unit holder 8 are changed according to the part of the brain of the subject M whose function is to be measured. In this embodiment, four probe units 7 are held by a probe unit holder 8, as shown in FIG. The probe unit holder 8 has a fixing belt (not shown). With the probe unit holder 8 mounted on the head of the subject M, the probe unit holder 8 is fixed to the head of the subject M by attaching a fixing belt to the head of the subject M. FIG.

The main unit 5 includes a main control section 9, an operation section 11, a storage section 13, and a display section 15, as shown in FIGS. The main control unit 9 includes information processing means such as a central processing unit (CPU), for example. The main control unit 9 centrally controls various components of the brain function measuring device 1 .

The operation unit 11 is for inputting operator's instructions regarding the operation of the brain function measuring device 1 , and the main control unit 9 performs overall control according to the instructions input by the operator to the operation unit 11 . In this embodiment, a keyboard provided in the computer is used as the operation unit 11 . Examples of the operation unit 11 include a touch panel, a mouse, a dial switch, a push button switch, etc., in addition to the keyboard.

The storage unit 13 stores various programs executed by the main control unit 9 and various information such as various data measured by the measurement unit 3 . An example of the storage unit 13 is a nonvolatile memory. The display unit 15 displays various information such as the conditions for measurement by the measurement unit 3 and various data measured by the measurement unit 3 . An example of the display unit 15 is a liquid crystal monitor.

The probe unit 7, as shown in FIG. In this embodiment, the probe unit 7 comprises two light-transmitting probes 19 and two light-receiving probes 21 . The number of light-transmitting probes 19 and light-receiving probes 21 included in the probe unit 7 may be changed as appropriate.

The light output device 17 is a light source that generates light, and outputs near-infrared light with wavelengths of 780 nm, 805 nm, and 830 nm, for example. An example of the light output device 17 is a light emitting diode (LED) or a semiconductor laser. The light output device 17 is connected to the light transmission probe 19 by a light transmission member such as an optical fiber, and the light generated by the light output device 17 is transmitted to the light transmission probe 19. .

The light transmission probe 19 has a shape extending in one direction. One end side of the light transmitting probe 19 is connected to the light output device 17 , and the other end side of the light transmitting probe 19 is configured to be able to contact the head skin 25 of the subject M. FIG. The light transmitting probe 19 emits light to the subject M while being in contact with the head skin 25 of the subject M, as shown in FIG. The light emitted from the light transmitting probe 19 is transmitted to the brain region 29 of the subject M via the head epidermis 25 and the skull 27 . An example of a material that forms the light transmitting probe 19 is a light guide that includes a columnar glass member. Accordingly, the light output device 17 and the light transmitting probe 19 constitute a light irradiation unit 20 for irradiating the brain of the subject M with light.

The light-receiving probe 21 has a configuration similar to that of the light-transmitting probe 19 . That is, the light-receiving probe 21 has a shape extending in one direction, and is configured by, for example, a ride guide having a columnar glass member. One end side of the light-receiving probe 21 is connected to the light detection unit 23 , and the other end side of the light-receiving probe 21 is configured to be able to contact the head skin 25 of the subject M. The light receiving probe 21 is configured to receive light and transmit the received light to the light detection unit 23 .

The diameter of one end side of the light receiving probe 21 is configured to be larger than the diameter of a through hole 72, which will be described later. The diameter of the light receiving probe 21 on the other end side is configured to be equal to or smaller than the diameter of the through hole 72 . That is, the other end side of the light receiving probe 21 is configured so as to be able to be inserted through the through hole 72 provided in the container 71 .

The photodetection unit 23 includes a photodetector 31 and an A/D converter 33 . The photodetector 31 detects the light received by the light receiving probe 21 and amplifies the optical signal. Examples of the photodetector 31 include a photomultiplier tube or a photodiode. The A/D converter 33 converts the optical signal detected and amplified by the photodetector 31 from an analog signal to a digital signal. The A/D converter 33 is mounted on a flexible substrate 73 as will be described later. The A/D converter 33 corresponds to the A/D converter in the present invention.

The measurement unit 3 further includes a measurement unit control section 35. The measurement unit control section 35 is configured by a computer including a processor and memory. The measurement unit control section 35 controls various configurations in the measurement unit 3, for example, the light output device 17 and the light detection unit 23. FIG. The measurement unit control section 35 receives control from the main control section 9 and controls various configurations in the measurement unit 3 . The measurement unit control section 35 is connected to the light irradiation unit 20 via the cable 18 . The measurement unit control section 35 is also connected to the light detection unit 23 via the cable 18 .

<Measurement operation using brain function measuring device>
Here, an operation for measuring the brain function of the subject M using the brain function measuring device 1 will be described. When performing measurement using the brain function measuring apparatus 1, the light transmitting probe 19 and the light receiving probe 21 are brought into contact with the head skin 25 of the subject M as shown in FIG. Then, the measurement light L in the near-infrared region output from the light output device 17 is emitted from the light transmission probe 19 to the head skin 25 .

Note that as shown in FIG. 3 and the like, the direction toward the head skin 25 with respect to the probe unit 7 held by the probe unit holder 8 is the z1 direction, and the direction away from the head skin 25 is the z2 direction. Hereinafter, the z1 direction and the z2 direction are collectively referred to as the z direction. A plane perpendicular to the z direction is defined as an xy plane, and two directions perpendicular to each other on the xy plane are defined as an x direction and a y direction.

The measurement light L emitted to the head epidermis 25 reaches the brain region 29 via the skull 27 , and part of the measurement light L passes through the brain region 29 . Then, the measurement light L transmitted through the brain region 29 and emitted from the epidermis 25 of the head is made incident on the light receiving probe 21 . At this time, one measurement channel CH having a banana shape is formed by a region serving as a path of the measurement light L between one light transmitting probe 19 and one light receiving probe 21 .

The measurement light L received by the light receiving probe 21 is transmitted to the light detection unit 23 . The measurement light L is detected by the photodetector 31 provided in the photodetection unit 23 . Further, the detection signal of the measurement light L is amplified in the photodetector 31 . The amplified detection signal of the measurement light L is converted into a digital signal by the A/D converter 33 . The digital-converted detection signal is transmitted to the main unit 5 via the cable 6 . The main control unit 9 calculates measurement data indicating the brain activity of the subject M based on the digital signal data.

Specifically, reflecting the brain activity of the subject M, when the amount of blood hemoglobin in the brain increases at the activated site, the amount of measurement light L absorbed by hemoglobin increases. Therefore, it is possible to acquire changes in the amount of hemoglobin associated with brain activity based on the intensity of the measurement light L acquired. Oxyhemoglobin, which is bound to oxygen, and deoxyhemoglobin, which is not bound to oxygen, have different absorption characteristics. Therefore, the brain function measuring apparatus 1 performs measurement using measurement light L of multiple wavelengths (for example, wavelengths of 780 nm, 805 nm, and 830 nm) considering the difference in light absorption characteristics.

The main control unit 9 calculates the temporal change in the concentration of oxyhemoglobin and the temporal change in the concentration of deoxyhemoglobin based on the intensity of the measurement light L of each wavelength received by the light receiving probe 21 . Based on the time change of each hemoglobin concentration calculated for the time change, changes in the blood flow in the brain of the subject M and the activation state of oxygen metabolism can be acquired noninvasively. The main control section 9 corresponds to the brain function measuring section in the present invention.

The measurement unit 3 includes a plurality of light transmitting probes 19 and a plurality of light receiving probes 21. By measuring the brain region 29 with a plurality of measurement channels CH using a plurality of light-transmitting probes 19 and a plurality of light-receiving probes 21, it is possible to obtain data indicating a two-dimensional distribution of brain activity.

Brain function measurement is started by an input operation using the operation unit 11, for example. When the operator uses the operation section 11 to input various instructions regarding measurement, the main control section 9 controls the measurement unit control section 35 to start measurement. When the measurement is started, the measurement unit control section 35 controls the light output device 17 so that the measurement light L is sequentially output to each of the light transmitting probes 19 at a predetermined cycle.

The measurement unit control section 35 controls the light detection unit 23 in synchronization with the output of the measurement light L from the light output device 17 . That is, the measurement unit control section 35 controls the light detection unit 23 so that the light transmission probe 19 that outputs the measurement light L and the light reception probe 21 that constitutes the measurement channel CH detect the measurement light L. FIG. Further, the measurement unit control section 35 causes the detection signal of the measurement light L detected by the light detection unit 23 to be transmitted to the main control section 9 .

The main control unit 9 analyzes changes in the amount of hemoglobin associated with brain activity based on the detection signal of the measurement light L, and causes the display unit 15 to display the measurement results. After the predetermined task is executed, the operator inputs an instruction to the operation unit 11 to end the brain function measurement. When an input operation to end measurement is performed, the main control section 9 controls the measurement unit control section 35 to end the measurement, and this control ends a series of operations related to brain function measurement.

<Structure of probe unit holder>
Here, the configuration of the probe unit holder 8 and the configuration for connecting the probe unit holder 8 and the probe unit 7 will be described with reference to FIG. 4 . 4 is a longitudinal sectional view of the probe unit holder 8. FIG.

The probe unit 7 includes a main body portion 39, a holding member 41, and a connecting member 43. The probe unit holder 8 has a connection member holding portion 47 and an opening portion 49 . The body portion 39 has a cylindrical configuration as a whole, and accommodates the light output device 17 and the light detection unit 23 therein. A detailed configuration of the body portion 39 will be described later. The holding member 41 holds the body portion 39 . The connecting member 43 is arranged on the holding member 41 and is a curved plate-like member.

The connection member holding portion 47 is arranged on the back side of the top of the probe unit holder 8 and holds the connection member 43 . That is, the plate-shaped connection member 43 is connected to the holding member 41 at one end thereof, and is connected to the connection member holding portion 47 at the other end thereof. Therefore, the probe unit 7 and the probe unit holder 8 are connected via the connecting member 43 . The opening 49 is provided in the probe unit holder 8 near the position where each probe unit 7 is arranged, and the connection member 43 is inserted through the opening 49 .

As shown in FIG. 4, the connection member 43 is arranged in a curved state so as to protrude in the direction indicated by symbol P1. The direction indicated by P1 is the direction from the head surface 25 of the subject M toward the inner peripheral surface of the probe unit holder 8, in other words, it corresponds to the direction opposite to the head skin 25 of the subject M. The direction from the inner circumferential surface of the probe unit holder 8 to the head surface 25 of the subject M is indicated by P2. The direction P2 corresponds to the direction opposite to the direction P1.

The connection member 43 is configured to be elastically deformable in directions P1 and P2. Therefore, when the subject M wears the measurement unit 3, when the head skin 25 of the subject M presses the probe unit 7 in the direction P1, the restoring force caused by the elastic deformation causes the pressing force in the direction P2 to be applied to the probe. Granted to Unit 7. That is, the probe unit 7 is pressed against the head skin 25 of the subject M by generating a pressing force in the direction P2 due to the elastic deformation of the connecting member 43 . As a result, the light-transmitting probe 19 and the light-receiving probe 21 can be reliably brought into contact with the head skin 25 .

<Structure of probe unit>
The configuration of the probe unit 7 will be explained in more detail. As shown in FIGS. 5 and 6, the body portion 39 of the probe unit 7 includes a base member 51, a cover member 53, a central shaft 55, a rotating shaft 57, a comb member 59, and a grip portion 61. I have.

A base member 51 holds the light output device 17 and the light detection unit 23 . In this embodiment, a disk-shaped member is used as the base member 51 . In this embodiment, as shown in FIG. 6, the base member 51 holds the light output device 17 and the light detection unit 23 so that the direction in which the light output device 17 and the light detection unit 23 extend is the z direction. there is At this time, the surface of the base member 51 is parallel to the xy plane.

The cover member 53 is a tubular member having an opening in the z1 direction, and is provided so as to cover the light output device 17 and the light detection unit 23 held by the base member 51 from the outside. A groove portion 51a is formed in the peripheral portion of the base member 51, and the side of the cover member 53 having the opening is configured to fit into the groove portion 51a.

The central shaft 55 is erected in the center of the base member 51 . The body portion 39 is configured to be rotatable around the central axis 55 . The rotating shaft 57 is arranged on the side surface of the base member 51 and is configured to protrude outward from the base member 51 . The rotating shaft 57 is configured to be rotatable around an axis 58 of the rotating shaft 57 . The base member 51 is configured to rotate about an axis line 58 together with a rotation shaft 57 . That is, by rotating the rotating shaft 57 around the axis 58, the body portion 39 can be displaced so as to be inclined with respect to the xy plane.

The comb-shaped member 59 is composed of a plurality of pin-shaped members. The comb-shaped member 59 is arranged so as to protrude from the base member 51 of the body portion 39 in the direction z1. The comb-shaped member 59 is configured to push through the hair 26 of the subject M as shown in FIG. 3 and the like. The comb member 59 is made of an elastically deformable material. An example of a constituent material of the comb-shaped member 59 is an elongated rod-shaped resin that can suitably push the hair 26 aside.

When measuring the brain function, the comb member 59 separates the hair 26 of the subject M by rotating the main body 39 around the central axis 55 . The comb-shaped member 59 pushes the hair 26 aside, so that the light-sending probe 19 and the light-receiving probe 21 can reliably contact the head skin 25 without being obstructed by the hair 26 . The tip of the comb-like member 59 has a rounded smooth surface. By having a rounded smooth surface, it is possible to avoid scratching the head skin 25 when the comb member 59 separates the hair 26 .

The gripping portion 61 is composed of two arc-shaped members, and the two members are arranged at positions facing each other with the central axis 55 as the center. By gripping the grip portion 61 , the operator can rotate the body portion 39 around the central axis 55 .

FIG. 7 is a cross-sectional view of the body portion 39 shown in FIG. 6 taken along the line AA. The base member 51 has the same number of through-holes 51b as the light transmitting probes 19 and the light receiving probes 21, as shown in FIG. An elastic member 51c is arranged on the inner peripheral surface of the through hole 51b of the base member 51. As shown in FIG. Each of the light-sending probe 19 and the light-receiving probe 21 is held by the base member 51 by fitting a later-described fitting portion 71b into a through hole 51b in which the elastic member 51c is arranged.

The elastic member 51c is configured to be elastically deformable in the z direction inside the through hole 51b. A spring or the like can be given as an example of a constituent material of the elastic member 51c. A restoring force caused by the elastic deformation of the elastic member 51c imparts an urging force in the z direction to each of the light transmitting probe 19 and the light receiving probe 21 .

The holding member 41 of the probe unit 7 has an opening 41a as shown in FIG. The holding member 41 is configured to hold the body portion 39 inside the opening portion 41a. Although the holding member 41 has an annular shape in this embodiment, the shape of the holding member 41 can be changed as appropriate. As shown in FIG. 9, the holding member 41 is configured to be divided into a first member 63 and a second member 64 in the direction in which the body portion 39 is inserted (the z-direction in this embodiment). By dividing the holding member 41 into the first member 63 and the second member 64 , the body portion 39 is configured to be detachable from the holding member 41 . The connecting member 43 is connected to the first member 63 of the holding member 41 .

A concave portion 65 is formed in the peripheral edge portion of the first member 63 and the second member 64 . By combining the first member 63 and the second member 64 , the recesses 65 provided in each are combined to form the insertion hole 66 . The insertion hole 66 is configured so that the rotation shaft 57 is inserted therethrough.

That is, the first member 63 and the second member 64 are configured to sandwich and hold the rotating shaft 57 in the direction in which the body portion 39 is inserted. By combining the first member 63 and the second member 64 so as to sandwich the rotating shaft 57 , the rotating shaft 57 can be rotated around the axis 58 in a state where the holding member 41 holds the body portion 39 . can be made By rotating the rotating shaft 57, the body part 39 can be moved in a direction inclined with respect to the xy plane. The direction in which the main body portion 39 is tilted by the rotation of the rotation shaft 57 is indicated by the symbol F in FIG.

<Structure of light detection unit>
The configuration of the photodetection unit 23 will be described with reference to FIGS. 10 to 15. FIG. The light detection unit 23 has a container 71 and a flexible substrate 73 . The housing container 71 is a tubular member as a whole, and houses the photodetector 31 and the flexible substrate 73 therein. In this embodiment, the storage container 71 is assumed to be a cylindrical member. Although FIG. 15 is a longitudinal sectional view of the photodetector unit 23, the photodetector 31 and the flexible substrate 73 are exceptionally cut away in sectional view.

The storage container 71 has a structure in which a body portion 71a and a fitting portion 71b are connected. The fitting portion 71b is a tubular member having a diameter smaller than that of the body portion 71a. The fitting portion 71b is fitted into the through hole 51b of the base member 51, and the lower surface of the body portion 71a is in contact with the upper surface of the base member 51, so that the base member 51 stably holds the container 71 of the light detection unit 23. Hold.

As shown in FIG. 10, the photodetector 31 is arranged on the inner bottom surface of the container 71, and the flexible substrate 73 is arranged on the photodetector 31 in a soldered state. FIG. 10 is a vertical cross-sectional view of the photodetector unit 23. For convenience of explanation, the photodetector 31 and the flexible substrate 73 are shown in a side view. As will be described later, the flexible substrate 73 is arranged on the photodetector 31 while being deformed into a cylindrical shape along the inner surface of the container 71 .

A through hole 72 is formed in the lower portion of the fitting portion 71b. The container 71 holds the light receiving probe 21 by inserting the light receiving probe 21 into the through hole 72 . The light receiving probe 21 is inserted through the through hole 72 of the fitting portion 71b so as to come into contact with the photodetector 31. As shown in FIG. That is, in the photodetection unit 23 , the light receiving probe 21 is in contact with the photodetector 31 , and the photodetector 31 is in contact with the flexible substrate 73 .

The configuration of the flexible substrate 73 will be explained using FIGS. 11 to 15. FIG. FIG. 11 is a plan view of the flexible substrate 73 in the initial state. In the initial state, the flexible substrate 73 has a flat plate shape as a whole. The flexible substrate 73 is made of a flexible material, and each portion of the flexible substrate 73 is configured to be bendable and deformable.

The flexible substrate 73 has a first portion 75 , a second portion 77 and a connecting portion 79 . The first portion 75 is a portion connected to the photodetector 31 and has a mounting portion 75a. The mounting portion 75a is a portion to which the wiring 81 included in the photodetector 31 is soldered. The photodetector 31 is mounted on the first portion 75 of the flexible substrate 73 by soldering the wiring 81 to the mounting portion 75a. Further, when the flexible substrate 73 is deformed into a tubular shape, the first portion 75 constitutes the bottom portion of the flexible substrate 73 which has a tubular shape. The first portion 75 is configured to be shaped and sized so that it can be placed on the inner bottom surface of the container 71 . In Example 1, it is assumed that the first portion 75 has a disk shape.

The A/D converter 33, the transfer circuit 83, and the connector section 85 are mounted on the surface (circuit mounting surface) of the second portion 77. FIG. When the flexible substrate 73 is deformed into a tubular shape, the second portion 77 constitutes the side peripheral portion of the flexible substrate 73 which is tubular. In the first embodiment, it is assumed that the second portion 77 has a rectangular shape extending in the y direction.

The connecting portion 79 connects the first portion 75 and the second portion 77 . In Example 1, it is assumed that the connecting portion 79 has a rectangular shape extending in the x direction. The shapes of the first portion 75 , the second portion 77 , and the connecting portion 79 may be changed as appropriate according to the shape of the inner surface of the container 71 . In addition to the A/D converter 33, the transfer circuit 83, and the connector portion 85, the second portion 77 also includes a wiring 82 for connecting each circuit and a signal processing circuit for processing the detection signal of the measurement light L as appropriate. ing. An example of the signal processing circuit is an amplifier circuit that amplifies the detection signal of the measurement light L, or the like.

The transfer circuit 83 is a data transfer circuit that transfers the detection signal of the measurement light L digitally converted by the A/D converter 33 . In the first embodiment, a serial peripheral interface (SPI: Serial Peripheral Interface) that performs serial communication is used as the transfer circuit 83 . The connector section 85 is a device that connects the measurement unit control section 35 and the flexible substrate 73 with the cable 18 . A detection signal of the measurement light L detected by the photodetector 31 is transmitted to the flexible substrate 73 and then quickly converted into a digital signal by the A/D converter 33 . The digital-converted detection signal is transmitted to the main unit 5 via the transfer circuit 83 , the connector section 85 and the cable 6 .

<Accommodation process of flexible substrate>
The process of deforming the flexible substrate 73 and accommodating it in the container 71 will be described with reference to FIGS. 12 to 15. FIG. First, the connecting portion 79 of the flat flexible substrate 73 as shown in FIG. 11 is bent to bring the second portion 77 into an upright state. FIG. 12 shows flexible substrate 73 with second portion 77 in an upright position.

After placing the second part 77 in the upright state, the second part 77 is deformed so that both wings (both ends in the longitudinal direction) of the second part 77 are curved inward. By curving both wings of the second portion 77, the second portion 77 is deformed into a cylindrical shape as shown in FIG. By deforming the second portion 77 into a tubular shape, the flexible substrate 73 is deformed into a tubular body having the opening portion 76 with the first portion 75 as the bottom surface and the second portion 77 as the side surface.

In the cylindrically deformed second portion 77 , the circuit mounting surface on which the A/D converter 33 and the like are mounted is configured to be the inner peripheral surface of the cylindrical body made up of the second portion 77 . Therefore, the outer peripheral surface of the tubular body composed of the second portion 77 is a flat surface on which no circuit is mounted. The flexible substrate 73 deformed into a cylindrical body has an opening 76 on the z2 direction side. Therefore, the cable 18 can be connected to the connector portion 85 from the outside of the flexible substrate 73 by passing through the opening portion 76 .

After deforming the flexible substrate 73 into a cylindrical body, the light detection unit 23 is formed by combining the light receiving probe 21, the photodetector 31, the flexible substrate 73, and the container 71, as shown in FIG. First, the other end side of the light receiving probe 21 is inserted from above the container 71 into the through hole 72 of the fitting portion 71 b of the container 71 . Since the diameter of one end side of the light receiving probe 21 is larger than the diameter of the through hole 72, as shown in FIG. . Therefore, the light-receiving probe 21 is stably held by the container 71 .

After combining the light receiving probe 21 and the storage container 71, the photodetector 31 is mounted on the inner bottom surface of the storage container 71 extending in the z direction. The mounted photodetector 31 is connected to one end side of the light receiving probe 21 projecting upward from the through hole 72 . After the photodetector 31 is mounted on the inner bottom surface of the container 71 extending in the z-direction, the flexible substrate 73 deformed into a cylindrical body is accommodated inside the container 71 from the z-direction. At this time, the photodetector 31 and the flexible substrate 73 are connected by soldering the wiring 81 provided in the photodetector 31 and the mounting portion 75 a of the first portion 75 .

By using a material having elasticity as the material of the flexible substrate 73, when the flexible substrate 73, which is flat in the initial state, is deformed into a cylindrical body, the second portion 77, which is curved and deformed into a cylindrical shape, is deformed. A restoring force G acts to restore the plate shape. That is, in a state in which the flexible substrate 73 deformed into a cylindrical body is accommodated inside the container 71 , a restoring force G acts on the inner surface of the container 71 from the flexible substrate 73 . The restoring force G acts in a direction to press the inner surface of the container 71 outward. Therefore, due to the action of the restoring force G, the flexible substrate 73 can be stably held inside the container 71 without using a fixing tool such as a screw for the flexible substrate 73 .

The photodetection unit 23 according to the first embodiment includes a photodetector 31 that detects the measurement light L and transmits a detection signal, and an A/D converter 33 that converts the detection signal of the measurement light L from an analog signal to a digital signal. It has a configuration in which the flexible substrate 73 provided therein is housed inside the housing container 71 . Therefore, since the photodetector 31 and the A/D converter 33 in the photodetection unit 23 are in close proximity, the detection signal of the measurement light L received by the light receiving probe 21 can be rapidly converted into a digital signal. In other words, since the distance over which the measurement light L is transmitted before digital conversion is performed can be greatly shortened, reduction in the measurement light L due to transmission of the measurement light L in the form of an analog signal can be avoided. As a result, the S/N ratio of the signal detected by the photodetection unit 23 can be improved.

In addition, in the brain function measurement device, the measurement unit attached to the head of the subject M is required to be small and lightweight. Therefore, in the brain function measuring device 1 according to the present invention, by deforming the flexible substrate 73 into a cylindrical body, the area occupied by the flexible substrate 73, which was flat in the initial state, can be greatly reduced. That is, since the flexible substrate 73 having the A/D converter 33 can be accommodated inside the photodetection unit 23 while maintaining the size of the photodetection unit 23 small, the S/N ratio in the photodetection unit 23 can be improved and the photodetection can be performed. Both miniaturization of the unit 23 can be realized.

The storage container 71 has a cylindrical shape extending in the z direction, and stores the photodetector 31 and the flexible substrate 73 deformed into a cylindrical body extending in the z direction while being connected in the z direction. With such a configuration, the photodetection unit 23 as a whole has a shape extending in the z-direction, so that the area occupied by the flexible substrate 73 and the photodetection unit 23 in the xy plane can be reduced. In other words, since the area occupied by the light detection unit 23 on the surface of the head skin 25 of the subject M can be reduced, the number of measurement channels CH for measuring the brain function of the subject M in the brain function measuring device 1 is increased. be able to.

In the brain function measuring device 1 according to Example 1, the flexible substrate 73 on which the A/D converter 33 is mounted is deformed into a small size and accommodated in the accommodation container 71 of the photodetection unit 23 . Therefore, in the brain function measuring apparatus 1 , the photodetector 31 and the A/D converter 33 can be arranged on the side of the measurement unit 3 attached to the head of the subject M, not on the side of the main unit 5 .

That is, in the brain function measuring device 1, a series of signal processing such as detection of the measurement light L, amplification of the light detection signal, and digital conversion of the light detection signal can be executed on the measurement unit 3 side. Therefore, unlike the conventional device in which the photodetection signal is digitally converted on the main unit side, the brain function measuring device 1 according to the first embodiment does not need to connect the measurement unit 3 and the main unit 5 with an optical fiber. That is, since a general electric signal transmission cable can be used as the cable 6, it is possible to avoid an increase in cost and a decrease in the durability of the signal transmission member due to the use of a large amount of optical fibers.

Next, Embodiment 2 of the present invention will be described with reference to FIGS. 16 to 19. FIG. The second embodiment differs from the first embodiment in the configuration of the flexible substrate 73 . Accordingly, the flexible substrate 73 according to the second embodiment is distinguished from the flexible substrate 73 according to the first embodiment by attaching a reference numeral 73A. On the other hand, the same reference numerals are assigned to the configurations common to the first embodiment, and the description thereof is omitted. Similar to FIG. 15, FIG. 19 is a partially cutaway cross-sectional view of the photodetector 31 and the flexible substrate 73A.

FIG. 16 is a plan view of a flexible substrate 73A according to Example 2. FIG. In the initial state, the flexible substrate 73A has a cross-shaped plate shape as a whole. The flexible substrate 73A includes a third portion 91 and a connecting portion 93 in addition to a first portion 75, a second portion 77 and a connecting portion 79. As shown in FIG. The first portion 75 has a mounting portion 75 a connected to the photodetector 31 . The second part 77 has a rectangular shape extending in the y-direction, and has the A/D converter 33 and the transfer circuit 83 on the top side. The third portion 91 has a rectangular shape and has a connector portion 85 on the lower surface side. The connecting portion 93 connects the second portion 77 and the third portion 91 .

A process of deforming the flexible substrate 73A and storing it in the container 71 in the second embodiment will be described. First, the connecting portion 79 is bent with respect to the flat flexible substrate 73A as shown in FIG. 16 so that the second portion 77 is raised. Next, by bending the connecting portion 93 , the third portion 91 is brought into an upright state in which the third portion 91 protrudes closer to the central portion of the first portion 75 than the second portion 77 . FIG. 17 shows the flexible substrate 73A with the second portion 77 and the third portion 91 in an upright state.

After placing the second part 77 and the third part 91 in the upright state, the second part 77 is deformed so that both wings of the second part 77 are curved inward in the same manner as in the first embodiment. By curving both wings of the second portion 77, the second portion 77 is deformed into a cylindrical shape as shown in FIG. By deforming the second portion 77 into a cylindrical shape, the flexible substrate 73A is deformed into a cylindrical body having the opening portion 76 with the first portion 75 as the bottom surface and the second portion 77 as the side surface. In the tubular body, the third portion 91 is arranged above the second portion 77 deformed into a tubular shape. Further, by bending the connecting portion 93, the third portion 91 has a shape protruding from the side peripheral portion to the central portion of the flexible substrate 73A.

After deforming the flexible substrate 73A into a cylindrical body, the light receiving probe 21, the photodetector 31, the flexible substrate 73A and the container 71 are combined to form the photodetection unit 23 as shown in FIG. Since the process of combining is the same as that of the first embodiment, detailed description is omitted. As described above, even with the configuration of the flexible substrate 73A as shown in FIG. 16, the flexible substrate 73A is deformed from the initial flat plate shape into a cylindrical shape, as in the first embodiment, to form a compact shape. The flexible substrate 73</b>A that has been deformed into a shape can be accommodated in the accommodation container 71 .

Next, Example 3 of the present invention will be described with reference to FIGS. 20 to 22. FIG. The flexible substrate according to the third embodiment is denoted by reference numeral 73B to distinguish it from the flexible substrate 73 according to the first embodiment. FIG. 20 is a plan view of a flexible substrate 73B according to Example 3. FIG. In the initial state, the flexible board 73B has a flat plate shape extending in one direction as a whole. Although FIG. 22 is a cross-sectional view of the photodetector unit 23, the photodetector 31 is exceptionally a partially cutaway cross-sectional view.

A flexible board 73B according to the third embodiment includes a first portion 75, a second portion 77, a third portion 103, a fourth portion 105, a connecting portion 79, a connecting portion 109, and a connecting portion 111. ing. The first portion 75 has a mounting portion 75 a connected to the photodetector 31 . The second part 77 has the A/D converter 33 on the top side. The third portion 103 has a transfer circuit 83 on the upper surface side.

In Example 3, the first portion 75, the second portion 77, and the third portion 103 are all disk-shaped. The fourth portion 105 has a rectangular shape and has a connector portion 85 on the upper surface side. The connecting portion 79 connects the first portion 75 and the second portion 77 . The connecting portion 109 connects the second portion 77 and the third portion 103 . The connecting portion 111 connects the third portion 103 and the fourth portion 105 .

The second part 77 and the third part 103 are configured to have the same shape and size as the inner bottom surface of the container 71, like the first part 75. By forming the same shape and size as the inner bottom surface of the container 71, when the flexible substrate 73B is deformed into a columnar shape and accommodated in the container 71, a gap is generated between the flexible substrate 73B and the container 71. can be reduced. Therefore, the flexible substrate 73B can be held inside the container 71 more stably.

A process of deforming the flexible substrate 73B and accommodating it in the container 71 in Example 3 will be described. First, the flexible substrate 73B having a flat plate shape as shown in FIG. 20 is deformed by bending the connection portion 79 so that the first portion 75 and the second portion 77 overlap in the z-direction. Next, by bending the connecting portion 109, the flexible substrate 73B is deformed so that the second portion 77 and the third portion 103 overlap in the z direction. Finally, by bending the connecting portion 111 , the fourth portion 105 is made to stand above the central portion of the third portion 103 .

By deforming the flexible substrate 73B so that the first portion 75, the second portion 77, and the third portion 103 overlap in the z-direction, the flexible substrate 73B as a whole is deformed into a columnar shape extending in the z-direction. FIG. 21 shows the configuration of the flexible substrate 73B deformed into a columnar shape by bending the connecting portions 79-111. In Example 3, the disc-shaped first portion 75, second portion 77, and third portion 103 overlap in the z-direction, so that the flexible substrate 73B is folded and deformed into a cylindrical shape as a whole.

After deforming the flexible substrate 73B into a columnar body, the light receiving probe 21, the photodetector 31, the flexible substrate 73B, and the container 71 are combined in the same manner as in the first embodiment to form the photodetection unit 23 as shown in FIG. Let In this manner, the flexible substrate 73B as shown in FIG. 20 can be transformed from the initial flat plate shape into a columnar shape, and the flexible substrate 73B deformed into a compact shape can be accommodated in the container 71. can. In the third embodiment, the flexible substrate 73B is bent at the three connecting

portions

79, 109, and 111, but by increasing the number of portions to be bent and deformed, the flexible substrate 73B can be deformed into a smaller compressed shape.

<Effects of Configuration of Embodiment>
(Section 1) The photodetection unit 23 according to the present embodiment includes a photodetector 31 that detects light, a cylindrical container 71 that accommodates the photodetector 31, and an optical signal detected by the photodetector 31. and a flexible substrate 73 on which a signal processing circuit including an A/D converter 33 for converting from an analog signal to a digital signal is mounted. .

According to the photodetection unit 23 of the first aspect, since the signal processing circuit including the A/D converter 33 is mounted on the flexible substrate 73, the flexible substrate 73 is bent and deformed to have a smaller shape. can be done. Both the photodetector 31 and the A/D converter 33 are arranged inside the container 71 by placing the flexible substrate 73 inside the container 71 while being bent and deformed. That is, since the photodetector 31 and the A/D converter 33 can be arranged closer to each other, the optical signal detected by the photodetector 31 can be quickly converted from an analog signal to a digital signal. Therefore, since it is possible to avoid a decrease in optical signal intensity due to transmission of the optical signal in the form of an analog signal, it is possible to improve the S/N ratio of the optical signal while downsizing the photodetector unit 23 .

(Section 2) In the photodetection unit 23 described in Section 1, the flexible substrate 73 has a first portion 75 connected to the photodetector 31 and a signal processing circuit including the A/D converter 33 mounted thereon. and a connecting portion 79 connecting the first portion 75 and the second portion 77. The connecting portion 79 is bent so that the first portion 75 and the second portion 77 are orthogonal to each other, and the second portion By bending and deforming the portion 77 , the flexible substrate 73 is deformed into a cylindrical shape along the inner surface of the container 71 .

According to the photodetector unit 23 described in the second item, the connecting portion 79 connecting the first portion 75 and the second portion 77 constituting the flexible substrate 73 is bent, and the second portion 77 is bent and deformed. , the flexible substrate 73 can be deformed into a cylindrical shape along the inner surface of the container 71 . Therefore, the flat flexible substrate 73 can be deformed into a smaller cylindrical shape. Further, with such a configuration, a pressing force G is applied from the flexible substrate 73 to the inner surface of the container 71 due to the restoring force that causes the second portion 77 to return to its original shape. Since the flexible substrate 73 is held inside the container 71 by the pressing force G, the flexible substrate 73 can be stably held inside the container 71 without using fixing tools such as screws.

(Section 3) In the photodetection unit 23 described in Section 1, the flexible substrate 73B has a first portion 75 connected to the photodetector 31 and a signal processing circuit including the A/D converter 33 mounted thereon. and a connecting portion 79 connecting the first portion 75 and the second portion 77, and by bending the connecting portion so that the first portion 75 and the second portion 77 overlap each other, the flexible The substrate 73B is deformed into a folded state inside the container 71 .

According to the light detection unit 23 described in the third item, the first portion 75 and the second portion 77 are separated by bending the connecting portion 79 that connects the first portion 75 and the second portion 77 constituting the flexible substrate 73B. are superimposed on each other, the flexible substrate 73B can be deformed into a folded state inside the container 71 . Therefore, the flat flexible substrate 73B can be deformed into a smaller shape. Therefore, the volume occupied by the flexible substrate 73B can be further reduced, so that the light detection unit 23 can be further miniaturized.

(Section 4) Further, the brain function measuring apparatus 1 according to the present embodiment includes the light detection unit 23 according to any one of the first to third items and the light irradiation unit for irradiating the brain of the subject M with the measurement light L. 20 , and is electrically connected to a measurement unit 3 attached to the head of the subject M, and is electrically connected to the measurement unit 3 . and a main unit 5 having a main control unit 9 for acquiring measurement data on the brain activity of the specimen M.

According to the brain function measuring device 1 described in Item 4, by using a flexible substrate as the substrate on which the A/D converter is mounted, the substrate is bent and deformed so that it can be arranged inside the container provided with the photodetection unit. can do. Therefore, the photodetection unit can be miniaturized, so that the photodetection unit can be arranged on the side of the measurement unit attached to the head of the subject, not on the side of the main unit.

With such a configuration, the measurement light L emitted from the light irradiation unit 20 and transmitted through the brain of the subject M is detected by the photodetector 31 provided in the photodetection unit 23, and then promptly detected by the A/D converter 33. is converted into a digital signal. Therefore, it is possible to avoid reduction in optical signal intensity due to transmission of the optical signal in the form of an analog signal, thereby improving the S/N ratio of the optical signal. As a result, the accuracy of brain function measurement data can be further improved.

<Other Examples>
Note that the embodiments disclosed this time are illustrative in all respects and are not restrictive. The scope of the present invention includes the claims and all changes within the meaning and range of equivalents to the claims. As an example, the present invention can be modified and implemented as follows.

(1) In the above-described embodiment, a laptop computer is used as the main unit 5, but it is not limited to this. Other examples of the main unit 5 include a desktop computer or a trolley containing a computer.

(2) In the above-described embodiment or modified example, the measurement unit 3 and the main unit 5 are connected by the cable 6, and brain function measurement data is transmitted from the measurement unit 3 to the main unit 5 via the cable 6. is explained as However, in the brain function measuring device 1, the configuration for connecting the measurement unit 3 and the main unit 5 is not limited to a wired connection, and the measurement unit 3 and the main unit 5 may be connected wirelessly.

In the embodiment of the present invention, since the detection signal of the measurement light L is rapidly converted into a digital signal by the photodetection unit 23 arranged on the side of the measurement unit 3, the detection signal of the digitally converted measurement light L is wirelessly transmitted to the main unit. 5 can be sent. By wirelessly connecting the measurement unit 3 and the main unit 5, it is possible to expand the actionable range of the subject M when measuring brain function. The activity status of brain function can be measured in various situations.

(3) In Example 3 described above, when the flexible substrate 73 is deformed into a columnar shape, the first portion 75, the second portion 77, and the third portion 103 are superimposed so as to be parallel to each other. Not limited. That is, as shown in FIG. 23, the first portion 75 is arranged parallel to the inner bottom surface (here, the xy plane) of the container 71, while the second portion 77 and the third portion 103 are arranged in the container 71. The connecting portion 79 and the connecting portion 109 may be bent so as to be inclined with respect to the inner bottom surface. In addition, the second portion 77 and the third portion 103 are not limited to the configuration having the same size as the first portion 75, and the second portion 77 and the third portion 103 are smaller in size than the first portion 75. It may be configured as Also, the second portion 77 and the third portion 103 may have different shapes from the first portion 75 .

DESCRIPTION OF SYMBOLS 1... Brain function measuring device 3... Measurement unit 5... Main unit 6... Cable 7... Probe unit 8... Probe unit holder 9... Main control part 11... Operation part 13... Storage part 15... Display part 17... Optical output part 19... Light transmitting probe 20 Light irradiation unit 21 Light receiving probe 23 Light detecting unit 25 Head epidermis 29 Brain region 31 Photodetector 39 Main body 41 Holding member 43 Connecting member 51 Base member 53 Cover Member 57 ... Rotating shaft 59 ... Comb-shaped member 71 ... Container 73 ... Flexible substrate 75 ... First part 77 ... Second part 79 ... Connection part 83 ... Transfer circuit 85 ... Connector part

Claims

a photodetector for detecting light;
a cylindrical storage container that stores the photodetector;
a flexible substrate mounted with a signal processing circuit including an A/D converter that converts the optical signal detected by the photodetector from an analog signal to a digital signal;
with
The photodetector unit, wherein the flexible substrate is arranged inside the housing container in a state of being bent and deformed.
The photodetection unit according to claim 1,
The flexible substrate is
a first portion connected to the photodetector;
a second portion mounted with a signal processing circuit including the A/D converter;
a connecting portion that connects the first portion and the second portion;
with
By bending the connecting portion so that the first portion and the second portion are perpendicular to each other and bending and deforming the second portion, the flexible substrate is deformed into a cylindrical shape along the inner surface of the container. detection unit.
The photodetection unit according to claim 1,
The flexible substrate is
a first portion connected to the photodetector;
a second portion mounted with a signal processing circuit including the A/D converter;
a connecting portion that connects the first portion and the second portion;
with
A light detection unit in which the flexible substrate is deformed into a folded state inside the receiving container by bending the connecting portion so that the first portion and the second portion overlap each other.
a measurement unit that has a light detection unit according to any one of claims 1 to 3 and a light irradiation unit that irradiates light onto the brain of a subject, and that is mounted on the head of the subject;
a main body unit electrically connected to the measurement unit and having a brain function measurement unit that acquires measurement data relating to brain activity of the subject based on the optical signal digitally converted by the A/D converter; ,
A brain function measuring device.