JP6879546B2 - Brain function measuring device - Google Patents

Description

The present invention relates to a device for measuring brain function.

In recent years, functional near infrared spectroscopy (fNIRS) has been known as a simple brain function measurement method. For example, as shown in Patent Document 1, a measurement device (f) that employs this method (functional near infrared spectroscopy). Hereinafter, various "fNIRS devices") have also been devised.

Then, in Patent Document 2, a probe capable of temporally switching between irradiation and detection of light is arranged at each vertex of an equilateral triangle, and one point is used for irradiation at a certain time and the other two points are used for detection. , A measurement method (hereinafter referred to as "three-point double-direction method") in which an irradiation point goes around all vertices is disclosed.

Japanese Unexamined Patent Publication No. 2014-124380 JP 2015-100410

In the fNIRS device, in which the main body containing the light source and detector and the headset mounted on the head are connected by an optical transmission cable, the presence of the optical transmission cable is a major obstacle to making the device smaller and lighter. Therefore, it becomes difficult to reduce the load on the subject who wears the headset.

Here, some commercially available fNIRS devices do not use an optical transmission cable, and the light source element and the detection element are arranged directly on the surface of the scalp. However, in any device, the light source element and the detection element are arranged in one housing. Since only one of the light source and the detector is stored, there is a problem that the three-point double-direction method shown in Patent Document 2 cannot be realized.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a brain function measuring device capable of realizing a three-point bidirectional method while reducing a load on a subject.

In order to solve the above problems, the present invention is a brain function measuring device that measures the function of the brain by irradiating the brain of the subject with light, and is a detection means that is attached to the head of the subject and has a probe arranged therein. The probe includes a control means for controlling the probe and a measuring means for measuring the intensity of light reflected from the brain, and the probe includes a light source unit that irradiates the brain with light according to a control signal supplied from the control means. Provided is a brain function measuring device including a detection unit that detects light reflected from the brain and a light-shielding unit that optically separates the light source unit and the detection unit.

According to the present invention, it is possible to obtain a brain function measuring device capable of realizing a three-point bidirectional method while reducing the load on a subject.

It is a block diagram which shows the structure of the brain function measuring apparatus 1 which concerns on embodiment of this invention. It is a top view which shows the arrangement of the probe TP included in the detection part 3 shown in FIG. It is a figure which shows the plane structure seen from the top and the cross-sectional structure seen from the side which concerns on 1st Embodiment of the probe TP shown in FIG. It is a figure which shows the plane structure seen from the top and the cross-sectional structure seen from the side which concerns on the 2nd Embodiment of the probe TP shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the figure, the same reference numerals indicate the same or corresponding parts.

FIG. 1 is a block diagram showing a configuration of a brain function measuring device 1 according to an embodiment of the present invention. As shown in FIG. 1, the brain function measuring device 1 includes a measuring terminal 2 and a detecting unit 3, and the measuring terminal 2 includes a control unit 10, a data measurement unit 11, a storage unit 12, an operation unit 13, and a display unit 14. including.

Then, the detection unit 3 is connected to the control unit 10 and the data measurement unit 11 by the wire 7. More specifically, the wire 7 is connected to a plurality of probe TPs arranged in the detection unit 3, a control signal is supplied from the control unit 10 to the probe TP, and the intensity of light detected by the probe TP is determined. The indicated data is supplied from the probe TP to the data measurement unit 11.

Further, the control unit 10 is connected to the data measurement unit 11, the storage unit 12, the operation unit 13, and the display unit 14, and the storage unit 12 is connected to the data measurement unit 11 and the display unit 14. The display unit 14 is also connected to the operation unit 13.

FIG. 2 is a plan view showing the arrangement of the probe TP included in the detection unit 3 shown in FIG. As shown in FIG. 2, the probe TPs are arranged, for example, by hexagonal close packing at 30 mm intervals. At this time, the intermediate point of the adjacent probe TP becomes the measurement point M, but the distance between the adjacent measurement points M is shortened to 15 mm.

The brain function measuring device 1 having the above-described configuration realizes the measurement by the above-mentioned three-point double-direction method. That is, the control unit 10 supplies a control signal so as to selectively irradiate the plurality of probe TPs with light in order to execute the operation selected by the operation of the operation unit 13 by the user, and the plurality of probe TPs. The data measuring unit 11 is controlled so as to selectively measure the intensity of the light received in.

Further, the control unit 10 stores the light intensity measured by the data measurement unit 11 in the storage unit 12 in response to the operation of the operation unit 13 by the user, and stores the light intensity and the like stored in the storage unit 12. The data is displayed on the display unit 14. The control unit 10 can control the display of the display unit 14 according to the above operation, and the operation unit 13 can adjust the display function of the display unit 14 according to the above operation.

FIG. 3 is a diagram showing a plan configuration seen from above and a cross-sectional structure seen from the side according to the first embodiment of the probe TP shown in FIG. The arrows in the figure indicate the direction in which the light travels, and the same applies to FIG.

As shown in FIG. 3, the probe TP according to the first embodiment has a cylindrical housing 20, a detection light guide 21, an irradiation light guide 22, and a light source unit 23 housed in the housing 20, respectively. , A light-shielding unit 24, a light-receiving light-collecting mechanism 25, a detection unit 26, a polarizing filter 27 for the detection unit, a polarizing filter 28 for the light source unit, and a window unit 29 forming an end face of the housing 20.

Here, the light source unit 23 is arranged in the central portion of the housing 20 so that the light is irradiated along the central axis of the housing 20, and irradiates the light according to the control signal supplied from the control unit 10. .. Further, the detection unit 26 is arranged behind the light source unit 23 with the traveling direction of the light emitted by the light source unit 23 facing forward, and detects the light reflected by the brain.

Further, the irradiation light guide 22 is arranged on the irradiation surface of the light source unit 23, has a function of limiting the traveling direction of the light emitted by the light source unit 23, and is a light transparent medium having a mirror-finished inner surface. , It is composed of a large number of optical fibers bundled and fused to form a rod shape or a taper shape.

Further, the light receiving condensing mechanism 25 is arranged on the detection surface of the detection unit 26 and has a function of collecting the light reflected from the brain into the detection unit 26 to improve the light receiving efficiency. The detection light guide 21 is provided around the light source unit 23 and the irradiation light guide 22, and is provided between the light receiving condensing mechanism 25 and the window unit 29.

Further, the light-shielding unit 24 has a function of optically separating the light source unit 23 and the detection unit 26 to block light radiation from the light source unit 23 to the back portion, that is, the detection unit 26, and the light source unit 23. Is arranged to include.

According to the light-shielding unit 24 having such a configuration, accurate measurement of smaller reflected light from the brain is realized by avoiding detection by the detection unit 26 of light emitted weakly even when the light source unit 23 is turned off. can do.

At the same time, the light-shielding unit 24 may have a light-collecting mechanism for improving the light emission efficiency toward the front of the light source unit 23 (upward in FIG. 3).

Further, the polarizing filter 27 for the detection unit is provided between the detection light guide 21 and the window unit 29, and the polarizing filter 28 for the light source unit is provided between the irradiation light guide 22 and the window unit 29. The polarizing filter 27 for the detection unit and the polarizing filter 28 for the light source unit use the light emitted from the light source unit 23 and the light reflected by the hair or the head surface particularly close to the window unit 29 or the window unit 29. It functions to block light.

Here, the polarizing filter 28 for the light source unit is a linear polarizing filter, and the polarizing filter 27 for the detection unit is a straight line that polarizes light in a direction orthogonal to the polarization direction of the linear polarizing filter constituting the polarizing filter 28 for the light source unit. It is used as a polarizing filter.

Further, the polarizing filter 27 for the detection unit and the polarizing filter 28 for the light source unit may be circular polarizing filters in the same rotation direction. In this case, the polarizing filter 27 for the detection unit and the polarizing filter 28 for the light source unit are combined into a single circle. It can be a polarizing filter.

FIG. 4 is a diagram showing a plan configuration seen from above and a cross-sectional structure seen from the side according to the second embodiment of the probe TP shown in FIG. As shown in FIG. 4, the probe TP according to the second embodiment includes a cylindrical housing 20, one polarizing filter 27 for a detection unit housed in the housing 20, and a detection light guide. It is composed of 21, a detection unit 26, four polarizing filters for light source units 28, an irradiation light guide 22, a light source unit 23, a light shielding unit 24, and a window unit 29 forming an end face of the housing 20.

Here, since the probe TP according to the second embodiment shown in FIG. 4 has the same configuration as the probe TP according to the first embodiment shown in FIG. 3, the following are common points. The explanation in is omitted, and only the differences will be explained.

FIG. 4 shows a case where the probe TP according to the second embodiment includes a plurality of light source units 23 in the housing 20 and includes four light source units 23 as an example.

Then, as shown in FIG. 4, in the probe TP, one polarizing filter 27 for a detection unit, a detection light guide 21, and a detection unit 26 are arranged along the central axis of the housing 20. Further, four polarizing filters for a light source unit, an irradiation light guide 22, a light source unit 23, and a light shielding unit 24 are arranged symmetrically around the central axis so as to surround them in the central axis direction.

According to the brain function measuring device 1 according to the embodiment of the present invention as described above, fNIRS measurement by the three-point double-direction method having a sufficient spatial sampling density can be realized by a lightweight, compact and low-artifact configuration. Can be done.

Since the brain function measuring device 1 according to the embodiment of the present invention does not require an optical transmission cable, it is conceivable to integrate the measuring terminal 2 shown in FIG. 1 into an integrated circuit and mount it on the detection unit 3.

According to such a configuration, brain function measurement is performed by using only the headset including the detection unit 3 and a smartphone, tablet terminal, or personal computer for monitoring the data detected by the detection unit 3. The same function as that of the device 1 can be realized.

1 Brain function measuring device 3 Detection unit 10 Control unit 11 Data measurement unit 21 Detection light guide 22 Irradiation light guide 23 Light source unit 24 Light shielding unit 25 Light receiving condensing mechanism 26 Detection unit 27 Polarizing filter for detection unit 28 Polarizing filter for light source unit TP probe

Claims (5)

A brain function measuring device that measures the function of the brain by irradiating the subject's brain with light.
A detection means mounted on the subject's head and having a plurality of probes arranged on triangular lattice points at predetermined intervals.
A control means for controlling the plurality of probes and
It is equipped with a measuring means for measuring the intensity of the light reflected from the brain.
Each said probe
With a single housing
A plurality of light source units housed in the housing and irradiating the brain with the light in response to a control signal supplied from the control means.
A detection unit that is stored in the housing and detects the light reflected from the brain.
The stored in the housing, seen including a light shielding part for isolating said detector and light source parts optically,
The control means is a brain function measuring device that selectively switches between irradiation by the light source unit and detection by the detection unit in each of the probes. The detection unit is arranged on the central axis of the probe.
The brain function measuring device according to claim 1, wherein the plurality of light source units are symmetrically arranged around the central axis. The brain function measuring apparatus according to claim 1, wherein each probe further includes a plurality of irradiation light guide units that limit the traveling direction of light emitted by each of the light source units. The light-shielding portion
A first linearly polarized light that linearly polarizes the light emitted from the light source unit,
The brain function measuring apparatus according to claim 1, further comprising a second linearly polarized light that linearly polarizes the light incident on the detection unit in a direction orthogonal to the direction in which the first linearly polarized light is polarized. The light-shielding portion
A first circularly polarized light that circularly polarizes the light emitted from the light source unit in a certain rotation direction,
The brain function measuring apparatus according to claim 1, further comprising a second circularly polarized light that circularly polarizes the light incident on the detection unit in the same direction as the direction in which the first circularly polarized light is polarized.

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