JP2017108759A - Head-worn apparatus for brain activity detection and brain activity measuring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head-worn apparatus capable of measuring brain activity signals of an occipital region at a substantially same height position as an ear in the head without any interference with a device disposed near the ear, and a brain activity measuring system.SOLUTION: A first frame 21 to be disposed along the head part shape includes a base part 21A to be disposed at a position of an occipital region; and a fork part 21B extended from the base part 21A along the temporal faces. The base part 21A includes five electrodes E1-E5 disposed on an inner face thereof, and receiving members constitute a receiving-member row disposed in series along a surface orthogonal to a median plane of the head part. The fork part 21B is configured to have an elevation angle toward the forward with respect to a first virtual plane formed around a head-part periphery passing through three points of the occipital tuberosity, and left/right preauricular points.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a head-mounted device for detecting brain activity and a brain activity measuring system used for measuring brain activity.

Non-invasive imaging technology for brain activity by measuring electroencephalogram (electroencephalogram), magnetoencephalogram, cerebral blood flow (for example, BOLD effect: Blood Dependent Dependent), etc., can reduce the size of the measuring device and improve its portability. There is a growing need for medical and research as well as industrial applications. For industrial application, it is important that a brain activity measurement system (for example, an electroencephalograph) can be easily attached to a subject so that the measurement can be performed in a state where the burden on the subject is small.
In order to measure brain activity, it is necessary to ground a receiving member that receives a brain activity signal such as an electrode on the scalp of the subject. Therefore, generally, a head mounting device, for example, a cloth belt-like mounting band or a helmet or a receiving member such as an electrode fixed to the inner side of the helmet corresponding to the head shape, and the head mounting device is mounted and the electrode etc. Is grounded (abutted) on the scalp.
As an example of such a head-mounted device, the headset of Patent Document 1 is cited. The headset of Patent Document 1 is configured such that an electrode is attached to an attachment hole of a frame, and the tip of the electrode is grounded to the subject's scalp in a state of wearing as shown in a reference diagram showing the use state. The frame that constitutes the headset in the mounted state has a fork-shaped first portion that is divided into two portions, and extends upward from the center of the back of the subject, covering the top and front of the head from the back. On the other hand, the second portion extending from the occipital region in the left-right direction is arranged in a substantially horizontal direction from the center position of the occipital region to the temporal region and the frontal region. And the 2nd part is mounted in the base part position of the upper part of an ear (ring) at the temporal region.

Design Registration No. 1316295

However, in such a headset, for example, when a person who normally wears glasses is a subject, the temple of the glasses interferes with the second part of the frame while wearing the glasses. Therefore, it is necessary to remove the glasses and wear the headset. However, if the brain activity signal to be measured is a change in brain activity through vision, if you remove the glasses, you will not be able to see the object accurately, so in this state the measurement value that should be measured Can no longer be obtained. However, if you wear a headset and wear glasses at the same time, for example, you may not be able to set the headset accurately on the head, or the glasses may tilt or shift. is there. This is not limited to eyeglasses, and the same applies to the measurement of brain activity when a VR display (virtual reality display) or the like is used.
The flow of visual information is known to have a ventral path from the back to the side and a dorsal path from the back to the top. It is important to record and analyze brain activity for each visual information path. It is said that. Here, when recording the ventral route, it is important to record brain activity at positions on the O1-T5 and O2-T6 lines in the international 10-20 electrode method. It becomes the position of T7 and T8 near the root of. Therefore, if a brain activity receiving member such as an electrode is placed on the O1-T5 and O2-T6 lines, the headset will pass near the ear, causing interference with glasses and the like. It was. For example, even in Patent Document 1, the headset passes through positions T7 and T8.
Further, even when the brain activity signal to be measured is a change in brain activity through auditory sense, headphones are generally attached to the ear, so that the headset of Patent Document 1 similarly interferes with the second part of the frame. there is a possibility. That is, in order to accurately measure the brain activity signal, it is necessary to prevent the head-mounted device from being arranged around the ear as much as possible.
The present invention has been made paying attention to such problems of the prior art. The purpose is to provide a head-mounted device and a brain activity measurement system that can measure a brain activity signal of the back of the head that does not interfere with equipment arranged near the ear and is at the same height as the ear in the head. It is.

In order to solve the above-described problem, in the first means, a head-mounted device that acquires a brain activity signal through a receiving member that is mounted on the head and receives the brain activity signal is arranged along the head shape. A frame having a first portion disposed at a back head position, and a second portion extending from the first portion along a side surface of the head. At least two receiving members are arranged on the inner surface, and the receiving members constitute a receiving member row arranged in series along a plane orthogonal to the median head surface, and the second part is The first imaginary plane formed around the head passing through the three points of the occipital nodule and the left and right anterior pinna is configured to have an elevation angle toward the front.
That is, when the head mounting device is mounted so that the first portion is disposed at the back head position, at least two receiving members are arranged in series along a plane orthogonal to the median head surface. Forming a row, and with the first portion as a base point, the second portion has an elevation angle forward with respect to the first virtual plane, so that the head side face is not directed toward the ear direction. It will be extended toward the front upper part. In the head-mounted device having such a configuration, the second part is not disposed above and near the ear of the temporal region, and thus it is necessary to detect a brain activity signal by wearing glasses, headphones, or the like. Even in some cases, there is no interference between the equipment and the frame, and the person wearing the head-mounted device (the wearer) can wear glasses or headphones normally in the detection work, so that the wearer is stressed. Therefore, it is possible to detect a brain activity signal with higher accuracy.

Here, “the first virtual plane formed around the head passing through the three points of the occipital nodule and the left and right preauricular points” refers to measurement coordinate setting (for example, the international 10-20 electrode method) Etc.), a plane passing through a position intersecting with the ear that is always determined in a unified manner from the three points of the occipital nodule and the left and right anterior pinna. And when the 1st part arrange | positions in a back head position, it comprises the receiving member row | line | column arrange | positioned in series along the surface orthogonal to the head midline surface. Here, when the second portion extending along the side of the head from the first portion of the frame extends in parallel with the first imaginary plane, the position where the frame interferes with the ears or the ears It will be placed in the vicinity. In that case, there is a possibility of interference with equipment arranged near the ear such as glasses or headphones worn on the ear. Therefore, in the present invention, the second portion of the frame is configured to have an elevation angle toward the front with respect to the first virtual plane so as not to interfere with equipment arranged near the ear. In the present invention, only a first virtual plane and a second virtual plane are defined with reference to a measurement point of a human head as a living body, and hence a physically very precise plane is referred to. Not. A surface that can be regarded as a substantially flat surface from the object of the invention and the principle of the invention.
The fact that “at least two receiving members are disposed” means that the visual information transmitted to the primary visual cortex in the occipital region is divided into left and right in the ventral route, that is, the information in the right and left hemispheres. It is important because it is transmitted and processed.

Here, “brain activity” is generally measured, for example, as a difference in the amount of near infrared light due to absorption of a magnetic field generated by an external current flow, a potential difference (voltage difference) at different positions, oxygenated hemoglobin, deoxygenated hemoglobin, etc. it can. Such a “reception member that receives a brain activity signal” is, for example, an electrode for measuring an electroencephalogram for measuring a current change (a change in potential difference) associated with a nerve activity of the brain, or a current change caused by a brain activity as a magnetic field. Changes in cerebral magnetic field (cerebral magnetic field) measurement electrodes (elements) that are measured as changes and changes in cerebral blood flow (oxygen-cahemoglobin, deoxygenated hemoglobin, etc.) associated with brain activity For example, a probe for measuring near-infrared spectroscopy is used. As described above, the “reception member that receives a brain activity signal” can be selected in various ways depending on the brain activity to be measured. Of course, the present invention depends on the type and reception method of the “reception member that receives a brain activity signal”. It is not limited.
When the receiving member is an electrode, in order to reduce the measurement burden on the wearer, a dry electrode (hereinafter referred to as a dry electrode) that does not require application of conductive paste, gel, physiological saline or the like on the electrode at the time of use. However, it may be a wet type electrode (hereinafter referred to as a wet electrode) in which a conductive paste, gel, physiological saline or the like is applied on the electrode during use. For example, the electrode may be fixed in a fixed manner by embedding or the like at a predetermined position of the frame, or may be detachably fixed to a mounting hole formed at a predetermined mounting position.
The frame is preferably made of a material that is as light and hard as possible and has appropriate elasticity. The material is preferably wood or plastic, for example. In addition, an elastomer (elastic rubber) or the like may be used for a part of the frame even if it is not a single material.
Here, the “midline of the head” refers to a plane including the root of the nose, the top of the head, and the occipital nodule. In general, the right and left hemispheres of the brain are divided by the midline of the head. Here, the crown means the electrode position of Cz in the international 10-20 electrode method and the 10-10 method. In FIG. 8, the nasal root is Nz and the occipital nodule is Iz.

Further, as a second means, the receiving member row is arranged so as to exist on a second virtual plane that is parallel to the first virtual plane and not below the first virtual plane. The second portion is configured to have an elevation angle toward the front with respect to the second virtual plane.
In such a configuration, the plane (second virtual plane) on which the receiving member row exists is arranged so as to be parallel to the first virtual plane and not below the first virtual plane. If the entire frame is configured at the position (height) of the second virtual plane and the head is rotated in a headband shape as it is, the frame is arranged at a position where it interferes with the ear or very close to the ear. . In that case, there is a possibility of interference with equipment arranged near the ear such as glasses or headphones worn on the ear. Therefore, in the second means of the present invention, the second portion of the frame is configured to have an elevation angle forward with respect to the second virtual plane so as not to interfere with equipment arranged near the ear. It is.
As a third means, the second portion extends from the first portion along the left and right head side surfaces.
That is, the first means includes a configuration in which the second portion extends from the first portion along one head side surface. By comprising like 3rd means, the 1st part arrange | positioned in a back head position can be fixed to a head with sufficient balance. Here, the second part only needs to extend from any one of the first parts, and may extend from the center to the left or right or from both ends to the left or right. Moreover, it includes extending from a slightly different height instead of the same height. When it is necessary to change the weight of the second part on the left and right sides, for example, when it is necessary to put a battery or a communication device on one side, the height of the second part can be adjusted by adjusting the extension height. The weight balance of the mounting device can be adjusted.
As a fourth means, the receiving member row is arranged at a position adjacent to the first virtual plane.
In such a configuration, the first portion of the frame is arranged at a height adjacent to the first virtual plane, that is, the plane position intersecting the ear. However, since the second portion of the frame is configured as described above, the second portion extends away from the first virtual plane, so that the frame is surely positioned above the ear and in the vicinity thereof. It will not pass. Here, “adjacent” is a concept that it is not only strictly adjacent but also adjacent as a measurement position of brain measurement. For example, since the length from the root of the nose to the top of the head to the occipital nodule is about 35 to 40 cm in the adult head, 20% or less, that is, about 0 to 7 cm can be considered as adjacent. Here, the center of the receiving member row is preferably arranged 2 to 5 cm away from the first virtual plane because the brain activity of the occipital lobe becomes difficult to measure when it is too close or far from the first virtual plane.
Further, as a fifth means, the second part passes through the boundary region between the side and top of the wearer and reaches the frontal region with the frame disposed on the head.
In particular, if the second portion is extended in this way, the boundary region between the temporal region and the top of the head is a region separated from the vicinity of the ear, so the second portion does not interfere with the equipment disposed near the ear. Thus, the frame can be extended to the forehead, and the frame can be held against the head on the forehead side. In addition, about the position of the temporal region, the parietal region, and the frontal region in this specification, it is as described in FIG. The “boundary region” is not only a contact point of a region where each region is strictly in contact, but also a region having a certain size. For example, the boundary region between the temporal region and the parietal region includes a region from the region close to the temporal region in the temporal region to a region close to the temporal region in the temporal region.
As a sixth means, the receiving members are arranged so as to be line symmetric at the center position of the entire length of the receiving member row.
In such a configuration, the receiving member comes into contact with the head of the wearer (subject) in a well-balanced manner, and the balance of the weight and the pressure of the head-mounted device can be made more uniform. The wearing feeling of the wearing device can be improved. Moreover, the same position of the left and right hemispheres of the brain has a similar function, and information is transmitted almost simultaneously at the ventral side path. Therefore, it becomes possible to measure with high accuracy by making the receiving member line-symmetric.

Further, as a seventh means, the frame has elasticity, and an urging force that returns to the inside is generated by pushing the second portion outward in a direction away from the head.
If comprised in this way, the frame will generate | occur | produce the urging | biasing force which returns to the original by pushing the 2nd part of a flame | frame outwardly spaced apart with respect to a head. Then, prepare a frame having a second part that is configured to be slightly narrower than the head, spread the second part outwardly away from the head, and bring the first part into contact with the back of the head Put it on the side of the head. By doing so, the frame can sandwich the head by the urging force of the second portion, and the frame can be supported by the head. Thus, when the head mounting device is mounted, the frame can be mounted on the head without being supported by hanging over the base position of the upper part of the ear (the ear ring).
When the second part sandwiches the head, it may be contacted over a wide range along the side shape of the head, or may be contacted with only a part of the second part.
Further, as an eighth means, a contact area to the frontal region is provided in the second portion.
Thus, the head is not pinched in an unnecessary wide range, and stress is reduced when the frame is attached to the wearer. In addition, as much as possible, the one that is sandwiched on the front head side is separated from the first part that is in contact with the back head, and the stability of the frame to the head is improved.
Further, as a ninth means, the frame is supported on the head by the receiving member and the contact area.
As a result, the frame surrounds the head at a position that forms a three-point support triangle between the contact area of the front and left of the front portion of the second portion and the receiving member disposed on the back of the head in the frame. The head mounting device mounted on the head is very stable.

Further, as a tenth means, a weight member is disposed in the first portion.
If comprised in this way, the 1st part arrange | positioned in a low position compared with a 2nd part will be pulled down by the gravity of the mass of a weight member in a back head position, and was mounted | worn to the head Head mounted device is very stable. In general, the weight member may be a heavy object heavier than the light weight frame. In particular, it is preferable not to arrange the weight member only for increasing the weight, but also to use some functional member. Examples of the functional member include an amplifying device for amplifying a detected signal and a battery for supplying power to the amplifying device.
As an eleventh means, the weight member is accommodated in an accommodating portion formed in the first portion.
For example, when the weight member is also used as a functional member as described above, if the weight member is accommodated in the accommodating portion, the weight member can be separately accommodated in a process, and the weight member frame This is convenient because it is not necessary to carry out the processing together with the processing and can be replaced if the weight member is taken out of the accommodating portion.

Further, as a twelfth means, the second part extends from the both sides of the first part along the head side surface in a pair of left and right.
By doing in this way, the holding | maintenance to the head of a 1st part can be performed now with a better balance, and the sense of stability at the time of wearing of a head mounting apparatus can be improved.
As a thirteenth means, the elevation angle is 15 to 60 degrees.
If the elevation angle is too small, the second part of the frame will pass near the upper part of the ear and interfere with the wearing of glasses, headphones and the like. On the other hand, if the elevation angle is too large, the stability when worn on the head of the head-mounted device is lowered. Therefore, the elevation angle is preferably 15 to 60 degrees. More preferably, the elevation angle is 20 to 45 degrees because a sufficient space can be secured in the vicinity of the ear and the weight of the head-mounted device is applied downward when worn.
In addition, as a fourteenth means, the second portions are connected to each other, and one or two or more second frames arranged along the head shape are provided.
This improves the strength of the frame. Further, since the second frame follows the shape of the outer periphery of the head, the second frame is curved in an arch shape. When the second portion is configured to expand outward as in the above means 7, the movement follows the movement. The bending that can be done is allowed.
As a fifteenth means, at least one of the second frames is arranged on the frontal portion in a mounted state.
In particular, if the second frame is disposed on the forehead in the mounted state, the weight of the entire frame can be suspended from the head by the second frame at the upper position. The head-mounted device attached to is very stable. In particular, if there is an action of being sandwiched between the second portions of the frame, the stability is particularly increased. Furthermore, if the weight member is disposed in the first portion of the frame, the stability is further increased.
As a sixteenth means, one or more receiving members are arranged on the inner surface of the second frame.
Thereby, the brain activity signal can be detected by the receiving member also from the top of the head or the frontal region where the second frame is disposed. For example, when it is desired to measure brain information transmitted to the dorsal path with visual information, the brain of the receiving member in the first part of the frame located on the back of the head and the receiving member disposed on the inner surface of the second frame This is preferable because it can be analyzed by detecting a difference in activity. In addition to visual information, for example, when detecting brain activity such as cognition, hearing, and motor recall, it is preferable because it can be detected by the receiving member disposed in the second frame. Furthermore, if the second frame is arranged on the forehead, the brain activity from the frontal lobe can be detected.
As a seventeenth means, the receiving member is an electrode, and the brain activity signal is an electroencephalogram.
As a result, the electrical activity associated with the neural activity of the brain can be detected as an electroencephalogram. The brain activity includes spontaneous brain activity and evoked brain activity, but is not particularly limited in the present invention, and both can be dealt with. For example, visual information analysis is preferable because it can detect alpha waves of the occipital lobe by spontaneous brain activity, detection of visual evoked potentials and steady state visual evoked potentials by evoked brain activity, and the like. Further, in brain activity related to cognition, an event-related potential such as P300 can be detected. Moreover, brain activities such as the θ band and the High-γ band can also be detected.
As an eighteenth means, the receiving member is an element for detecting a change in magnetic field, and the brain activity signal is a brain magnetic field.
Thereby, the change of the magnetic field (magnetic field) accompanying the neural activity of the brain can be detected as the cerebral magnetic field (brain magnetic field). Since the brain magnetic field is not affected by the distortion of the brain signal due to the skull, cerebrospinal fluid, etc., compared to the brain wave, it is possible to expect accurate recording of the brain activity position. In addition, it is necessary for the electroencephalogram to contact the electrode with the scalp by scraping the hair, but an element for detecting the cerebral magnetic field is preferable because it can be measured even if it contacts the head from above the hair.
As a nineteenth means, a near-infrared light transmitting part is provided at a position adjacent to the receiving member, the receiving member is a near-infrared light receiving part, and the brain activity signal is cerebral blood flow. .
As a result, the light-receiving unit receives the reflection from the brain surface of the near-infrared light from the light-transmitting unit provided with the concentration change of oxygenated hemoglobin, deoxygenated hemoglobin, etc. accompanying the brain activity at the position adjacent to the receiving member. Can be detected.
The 17th to 19th means can be implemented in combination. For example, the receiving member of the first part of the frame is used as an electrode, the electroencephalogram from the occipital lobe is measured, and the cerebral blood flow in the frontal lobe is measured using the receiving member inside the second frame as a near-infrared light receiving unit. It is preferable that the amount of information on brain activity obtained at the same time can be increased. Further, for example, an electrode for detecting a brain wave and an element for detecting a brain magnetic field (brain magnetic field) may be arranged adjacent to the first part of the frame. In this way, measurement accuracy can be further improved.
Further, as the twentieth means, the brain activity is measured based on the brain activity signal obtained by the head-mounted device of any one of the first to nineteenth means.
In this way, it is possible to reduce the trouble of wearing the head mounting device on the wearer, and even if the spectacles or headphones are worn simultaneously with the head mounting device, the wearer (subject) is stressed. It is possible to provide a brain activity measurement system that detects brain activity without applying the.

  In the above invention, when the head-mounted device is mounted and the brain activity signal of the occipital region is measured, the head-mounted device can be mounted without interfering with the device arranged near the ear.

The perspective view from back diagonally upward of the headset of an embodiment of the invention. The perspective view from the front diagonal upper direction of the same headset. Bottom view of the same headset. Rear view of the same headset. The block diagram explaining the electrical constitution of the brain activity measuring system of an embodiment. Explanatory drawing explaining the division of the site | part in a head, and its name. Explanatory drawing of the state which looked at the state which mounted | wore the headset of embodiment to the head. The electrode arrangement | positioning figure which showed the position where the electrode as a premise using the headset of embodiment is set | placed.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.
First, a brain activity measurement system according to an embodiment of the present invention will be described. FIG. 5 is an explanatory diagram for explaining the electrical configuration of the electroencephalogram measurement system. The electroencephalogram measurement system includes a headset 1 as a head-mounted device and a computer 2. The headset 1 is provided with a plurality of electrodes E1 to E8 as receiving members, a preamplifier 4 for each of the electrodes E1 to E8, and one differential amplifier 5 to which the plurality of preamplifiers 4 are connected. The detailed configuration of the headset 1 will be described later.
Each of the electrodes E1 to E8 is connected to an interface disposed in the differential amplifier 5 via the preamplifier 4 and the differential amplifier 5, and potential data (voltage data) is obtained as an electroencephalogram acquired by the computer 2 via the interface. ) Is output. Input / output to / from the computer 2 via the interface may be wired or wireless. In this embodiment, a wireless system based on Bluetooth (registered trademark) is used. It can be freely changed to other communication standards such as wi-fi.
The preamplifier 4 is disposed for each of the electrodes E1 to E8, and amplifies the electroencephalogram voltage at the position acquired by each of the electrodes E1 to E8. The differential amplifier 5 includes a differential amplifier circuit, and calculates and amplifies an electroencephalogram voltage and potential difference obtained from a reference electrode (not shown). The reference is obtained from the right earlobe. The differential amplifier 5 is also connected to a ground electrode (not shown). Although there is no restriction | limiting about the electrode position of a ground electrode, In this Example, it is set as the same right earlobe as a reference electrode. Further, the differential amplifier 5 has a function of reducing noise by a built-in filter circuit. The potential data amplified by the differential amplifier 5 is output to the computer 2 as detection target data.
The computer 2 includes a CPU (central processing unit) 11, a storage device 12, and peripheral devices. The CPU 11 performs arithmetic processing based on a program stored in the storage device. The storage device 12 stores a basic program such as a program for controlling the operation of the CPU 11 and an OA processing program (for example, a Japanese input function or a printing function) that manages functions that can be commonly applied to a plurality of programs. ing. Furthermore, a program for capturing potential data, a program for calculating a potential difference, a program for estimating a current direction, a program for calculating the reliability of measurement data, and the like are stored. An input device 13 (mouse, keyboard, etc.) and a monitor 14 are connected to the CPU 11. Measurement results such as brain waves and differences obtained on the monitor 14 can be displayed.

Next, a detailed configuration of the headset 1 according to the embodiment of the present invention used in such an electroencephalogram measurement system will be described.
As shown in FIGS. 1 to 4, the headset 1 includes two frame bodies, a first frame 21 and a second frame 22. The first frame 21 is a hard long body made of antibacterial plastic that has a U-shaped appearance. The first frame 21 includes a base portion 21A as a first portion that hits the bottom portion of the U-shape, and a pair of fork portions 21B as second portions that project from the left and right sides of the base portion 21A so as to face each other. It consists of and. The base portion 21A surrounds the occipital position of the head in the lateral direction, and the fork portion 21B surrounds the left and right side surfaces of the head.
The base portion 21A is configured to be relatively wide and thick with respect to the fork portion 21B. The base portion 21A is configured to be thicker toward the center in the longitudinal direction and thinner toward the both sides (closer to the fork portion 21B). That is, a curved surface 23 that is curved in the width direction so as to be convex outward is formed on the outer periphery of the base portion 21A, and a reverse curved surface that is curved in the width direction so as to be concave outward on the lower side of the curved surface 23. 24 is formed. A portion where the curved surface 23 and the reverse curved surface 24 contact each other becomes a discontinuous boundary line and appears as an obtuse angle portion 25 that protrudes outward in the longitudinal direction of the base portion 21A. The inner periphery of the base portion 21A is not curved in the width direction, but is configured in a straight section.
A switch 26 is disposed at a central position in the longitudinal direction of the outer periphery of the base portion 21 </ b> A and facing the obtuse angle portion 25. A window 27 is formed at the center position in the longitudinal direction of the outer periphery of the base portion 21A, which is the same as the switch 26, and at an upper position of the base portion 21A. Acrylic frosted glass 28 is fitted in the window 27. The outer peripheral surfaces of the switch 26 and the frosted glass 28 are flush with the outer periphery of the base portion 21A in order to achieve design cooperation. An LED (not shown) is disposed in the window 27. The switch 26 is a power source for the electroencephalograph, and the LED arranged in the window 27 emits green light, indicating that the power is on. Further, when there is a problem in measurement such as a communication error with the computer 2, the LED disposed in the window 27 also emits red light to indicate an error.

The fork portion 21B is a portion formed integrally with the base portion 21A so as to form a continuous curved surface on the front and back surfaces and the upper and lower end surfaces. The fork portion 21B extends from the left and right positions in the longitudinal direction of the base portion 21A, and is configured to gradually narrow toward the front (that is, taper). A curved surface 30 that is curved in the width direction so as to protrude outward is formed on the outer periphery of the fork portion 21B. The curved surface 30 is continuously curved with the curved surface 23 of the base portion 21A. The inner periphery of the fork portion 21B is not curved in the width direction, and is configured in a straight section. The fork portion 21B is configured to have a uniform thickness, and is relatively thin compared to the thickness at the center in the longitudinal direction of the base portion 21A. Therefore, the base portion 21A is connected to the fork portion 21B with the thickness smoothly reduced at the transition portion from the base portion 21A to the fork portion 21B.
The first frame 21 configured in this way is configured to be bilaterally symmetric with a line segment passing in the width direction (vertical direction) near the longitudinal center of the base portion 21A as a boundary. Moreover, although it is hard based on the property of the raw material of the 1st flame | frame 21, as a whole, it can bend with elasticity and it can return to an original shape. The fork portions 21B arranged opposite to each other can be contacted and separated from each other outward and inward. When the forks 21B are urged outward and inward, an urging force is generated inside, and this is the return force to the original position. It becomes.
As an example of the size, in the present embodiment, the width of the base portion 21A at the center position is 33 mm and the thickness is 12 mm, the width adjacent to the widest fork portion 21B is 40 mm, and the thickness is 5 mm. Yes. The width of the fork portion 21B, which is the widest, at a position adjacent to the base portion 21A is 20 to 25 mm (because the connecting portion is not clear), and the thickness is 3 mm over the entire length.

A storage portion 31 is formed at the center of the inner surface of the base portion 21 </ b> A of the first frame 21. The storage part 31 is a housing made of antibacterial plastic, and is fixedly arranged in an embedded manner on the inner peripheral surface of the base part 21A. The storage part 31 is composed of an electrode base part 31A in which electrodes E2 to E4 described later are disposed, and a storage part main body 31B. The electrode base portion 31A is a plate-like portion formed on the inner surface of the base portion 21A so as to extend along the upper end of the base portion 21A so as not to protrude from the upper end. The storage portion main body 31B is a bulging portion that is formed in a horizontally long shape at the lower position of the electrode base portion 31A along the lower end of the base portion 21A so as not to protrude from the lower end. A differential amplifier 5 and a battery (secondary battery) (not shown) are accommodated in the accommodating portion main body 31B. Since both the differential amplifier 5 and the battery are sufficiently heavier in terms of material than the plastic constituting the first frame 21, the load concentrates on the storage portion 31 as the overall weight balance of the first frame 21. .
Four slots 32A to 32D are formed on the bottom surface of the storage portion main body 31B. In FIG. 3, the leftmost slot 32A is for a cable terminal when power is supplied from a personal computer via a cable. The adjacent slot 32B is an insertion port for a reference / ground electrode. A terminal of a cable with a clip (not shown) is connected to the slot 32B. Attach the clip of the cable with clip to the right earlobe and obtain the reference electrode and ground electrode. The adjacent slots 32C and 32D are preliminary input terminals. For example, it is used when input data from other electrodes is input, or when some input from the outside, for example, a subject is made to perform a certain operation such as pressing a button and the relationship between the input and the electroencephalogram is analyzed.

A plurality of (five) electrodes E <b> 1 to E <b> 5 are arranged in series on the inner surface of the base portion 21 </ b> A of the first frame 21. The electrodes E <b> 1 to E <b> 5 as receiving members are composed of a cylindrical synthetic rubber damper portion 33 and an alloy electrode body 34 exposed outward from the damper portion 33. The electrode main body 34 is configured by applying gold plating to a member of an integrally molded product obtained by shaving brass. The electrode body 34 has a crown-like appearance in which a large number (15 in this embodiment) of contact pieces of the same shape surround the disc at equal intervals. The preamplifier 4 is disposed on the back side of the disk of the electrode body 34.
Among the electrodes E1 to E5, the three central electrodes E2 to E4 are fixedly arranged on the electrode base portion 31A of the storage portion 31, and the electrodes E1 and E5 at both ends are base portions 21A by electrode base portions 38 integrated with the damper portion 33. It is fixedly arranged in an embedded manner on the inner peripheral surface. The five electrodes E1 to E5 are arranged in series on the same contour line in the back of the head when mounted on the head (that is, so as to be on the same horizontal plane in the circumferential direction), and at equal intervals (in this embodiment, the electrode body) 34 are arranged so as to be 30 mm apart between the central positions. The electrode E3 just at the center is arranged at the center in the longitudinal direction of the base portion 21A. The three central electrodes E2 to E4 are connected to the differential amplifier 5 via a data line (not shown) in the damper portion 33, and the electrodes E1 and E5 at both ends are in a passage (not shown) formed in the first frame 21. Is connected to the differential amplifier 5 via a data line (not shown).

Next, the second frame 22 will be described. The second frame 22 is arranged so as to span between the fork portions 21B on the front end side of the left and right fork portions 21B of the first frame 21. The second frame 22 surrounds the frontal portion of the head in the lateral direction. Pads 35 serving as contact portions when the left and right fork portions 21B are brought into contact with the side surfaces of the head are fixedly arranged in an embedded manner at the inner ends of the left and right fork portions 21B. It is supported so as to be sandwiched between the fork portion 21B and the pad 35. A large number of elliptical holes 36 for preventing slipping are formed on the surface of the pad 35. The second frame 22 is a thin plate-like long body made of an elastomer that has an arch-shaped appearance. Although the second frame 22 is hard based on the properties of the material, the second frame 22 is more flexible than the first frame 21 and can be bent elastically as a whole and return to its original shape.
The second frame 22 is formed with a ridge portion 22a having a Gaussian curved ridge shape protruding upward in the width direction at a central portion in the longitudinal direction. The raised portion 22a is a mark for indicating the center position when the headset 1 is mounted on the head. The second frame 22 is equally wide in the left-right direction from the position of the raised portion 22a, and both end positions are widest and are connected to the left and right fork portions 21B. As described above, the second frame 22 is not uneven in the width direction in the width direction, but the lower end surface is not uneven and exists on the same plane.
As an example of the size, in this embodiment, the width of the second frame 22 at the center position is 18 mm, the width of the narrowest portion is 15 mm, the length of the joint portion sandwiched between the fork portion 21B and the pad 35 is 30 mm, and the thickness Is 1.5 mm.

An electrode base portion 37 is disposed at the longitudinal center position of the second frame 22. The electrode base portion 37 is a member made of antibacterial plastic that is formed horizontally long along the longitudinal direction of the second frame 22. The electrode base portion 37 is attached so as to protrude slightly outward from the upper end of the second frame 22.
On the inner surface of the second frame 22, a plurality of (three) electrodes E6 to E8 having the same configuration as the electrodes E1 to E5 are arranged in series. The electrodes E6 to E8 are fixedly disposed on the electrode base portion 37. The electrodes E6 to E8 are arranged in series in the forehead while being mounted on the head, and the electrodes E6 and E8 are equally spaced from E7 (in this embodiment, 40 mm apart from the center position of the electrode body 34). Are arranged as follows. The electrode E7 that is exactly the center is disposed at the center position in the longitudinal direction of the second frame 22. The electrodes E6 to E8 are connected to a differential amplifier 5 through a data line (not shown) in a passage (not shown) formed in the second frame 22 and the first frame 21.

Next, a method for using the headset 1 in the electroencephalogram measurement system configured as described above will be described.
FIG. 8 is an electrode layout showing the positions where the electrodes are placed as a premise for using the headset 1 of the present embodiment. This method is called a 10-10 method (extended 10-20 electrode method) in which electrodes are arranged by dividing the nasal root and the occipital nodule and between the left and right anterior pinna points every 10%. Since FIG. 8 is a plan view, the electrode positions on the same contour line are arranged concentrically, but in the actual head, since the positions are the same, the electrode array arranged at that height can be viewed from the side. In this case, they are arranged in a straight line. The headset 1 according to the present embodiment is particularly used in FIG. 8 to measure the occipital and forehead potentials. Assume that the electrodes E1 to E5 of the first frame 21 are brought into contact with each other so as to correspond to the five positions of PO7, O1, Oz, O2, and PO8 as electrode positions of the back of the head. In addition, the electrodes E6 to E8 of the second frame 22 are brought into contact with each other so as to correspond to the three positions F3, Fz, and F4 as electrode positions of the forehead. These electrode positions are mainly positions for detecting brain waves related to visual information. Visual information of the ventral path can be mainly detected by the five electrodes at the back of the head, and the back information by the three electrodes at the front of the head and the five electrodes at the back of the head.
The region of the head can be roughly divided as shown in FIG. The headset 1 is attached to such a head. The headset 1 to be used is selected from a plurality of types according to the size of the subject's head. This mounting operation may be performed by the subject himself or by an operator who operates the system.

First, the headset 1 is placed on the head so that the electrodes E1 to E5 of the first frame 21 are arranged on the back of the head. At substantially the same time, the left and right fork portions 21B are lowered from the top of the head toward the temporal region. At this time, the fork portion 21B is slightly pushed left and right to apply a spring force (restoring force) to the first frame 21. At this time, the second frame 22 also expands. Then, the front of the headset 1 is lowered so that the expanded left and right fork portions 21B do not interfere with the temporal region, and the electrodes E6 to E8 of the second frame 22 are brought into contact with the frontal region. Then, when the fork portion 21B spread in this state is displaced by its own urging force in the return direction to the original position, the pad 35 on the inner surface of the fork portion 21B comes into contact with the side surface of the forehead and sandwiches the head from the left and right. It becomes. The headset 1 is held on the head by the left and right pads 35 and the electrodes E6 to E8 (state shown in FIG. 7).
Here, a slightly more precise mounting position of the headset 1 will be described.
When the electrodes E1 to E5 of the first frame 21 are arranged on the occipital region, first, the electrode E3 is arranged so as to be positioned slightly above the occipital nodule as a target. The occipital nodule is located immediately below the electrode position 0z at the center in the left-right direction of the occipital region. Here, a plane A passing through the left and right anterior pinna and the nasal root is assumed with the occipital nodule as a reference. The plane A is orthogonal to the midline of the head. The electrode rows of the electrodes E6 to E8 of the second frame 22 are arranged on the plane B. At this time, the plane B is parallel to the plane A.
With such a headset 1 mounted, the fork portion 21B of the first frame 21 extends from the back of the head to the front of the head through the vicinity of the boundary between the head and the top of the head. That is, the fork portion 21B is disposed so as to extend obliquely forward and upward in the C direction with an elevation angle with respect to the plane A while substantially avoiding the temporal region. In the present embodiment, the elevation angle is set to about 30 degrees with reference to the lowermost position (point p in FIG. 7) of the base portion 21A of the first frame 21. The second frame 22 is arranged so as to surround the forehead from the fork portion 21B extended to a position above the forehead. In the present embodiment, the headset 1 is thus worn and the brain waves are measured.

By configuring as described above, the following effects are achieved in the above embodiment.
(1) When the headset 1 is correctly mounted, the electrodes E1 to E5 are brought into contact with the five horizontal positions PO7, O1, Oz, O2, and PO8 in the back of the head. Then, when the arrangement direction of the electrodes E1 to E5 is extended in a headband shape in the temporal direction, it passes immediately above the ear (extension direction of B in FIG. 7). If the headset 1 is in such a direction, it becomes difficult to use the equipment worn on the ear, such as glasses or headphones. However, in the above embodiment, when the headset 1 is correctly mounted, the fork portion 21B that extends forward to hold the headset 1 is located near the boundary between the occipital region and the temporal region on the side of the head. The fork portion 21 is not disposed near the ear because it is configured to pass through to the forehead. Therefore, when the brain waves are measured, the equipment will not interfere with the test when the subject wears eyeglasses and performs a visual test, or when the test is performed with the headphones attached. .
(2) Since the headset 1 is supported by the head in a balanced manner on the head by the electrodes E1 to E5 (particularly the center electrode E3) on the back of the head and the pad 35 near the tip of the fork 21, the headset 1 is stable. Holds firmly.
(3) In the headset 1, the electrodes E <b> 6 to E <b> 8 of the second frame 22 come into contact with the head at the frontal portion, and the downward displacement of the headset 1 is prevented.
(4) Since the first frame 21 is provided with the differential amplifier 5 serving as a weight member and a battery at a position that is the lowermost end of the base portion 21A, the base portion 21A is firmly held by the back of the head. Thus, the stability of the headset 1 is improved.
(5) Since the inner periphery of the base portion 21A and the inner periphery of the fork portion 21B are not curved in the width direction, the surface of the first frame 21 is easily slid in the width direction. Therefore, it is easy to operate, for example, when wiping and cleaning the inner peripheral surface and attaching to and detaching from the head.

The above embodiments are merely described as specific embodiments for illustrating the principle of the present invention and the concept thereof. That is, the present invention is not limited to the above embodiment. The present invention can also be embodied in the following modified form, for example.
In the above embodiment, the fork portion 21B of the first frame 21 has an elevation angle such that it passes through the vicinity of the boundary between the temporal region and the top of the head from the back of the head, but this angle can be changed as appropriate. is there. For example, since the vine of the glasses only has to be on the base of the ear, it is not necessary to extend the fork portion 21B with a large elevation angle. In addition, when a large equipment such as headphones is attached, a large elevation angle is preferable. Therefore, the elevation angle is preferably about 15 to 60 degrees. In particular, it is preferably 20 to 45 degrees.
The electrodes E1 to E5 at the back of the head are present on the same plane, but may be separately provided with electrodes arranged at positions that do not exist on the same plane (that is, measurement positions having different heights). For example, the headset 1 may have electrodes for measurement at a position of lz having different heights in FIG. For example, the present invention can be applied even to electrode arrangements such as P3, P4, O1, and O2 in the international 10-20 electrode method.
-You may make it change the number and space | interval of the electrodes E1-E5 of a back head. For example, T5, O1, O2, and T6 and electrodes may be arranged in the international 10-20 electrode method.
The above-described sizes of the first frame 21 and the second frame 22 of the headset 1 are merely examples, and in practice, several size differences according to the size of the head are prepared.
The embodiment of the present invention is designed to fit a standard head size. Since there is a difference in the size of the head, such as a woman being small and a man being large, an elastomer or the like may be used for a part of the headset 1 so as to correspond to the difference. Further, the angle of the second frame may be made variable. Such an arrangement is free and is included in the present invention.
The shape of the headset 1 is an example of the above embodiment. The materials for the first frame 21 and the second frame 22 constituting the headset 1 may be other than those described above.
Since the headset 1 is supported at three points by the electrodes E1 to E5 (particularly the central electrode E3) and the pad 35 near the tip of the fork portion 21, the second frame 22 is not necessary.
As long as the position of the second frame 22 is between the fork portions 21, it may be a position other than the position near the tip. Two or more second frames 22 may be arranged between the fork portions 21. Alternatively, frames may be provided in various directions on the basis of the first frame 21 and the second frame 22 in order to arrange the electrodes at the electrode positions in FIG.
-The shape of the electrode main body 34 in the said embodiment may be other than the above.
The electrode body 34 in the above embodiment is configured to be embedded in the head cap set 1 from the beginning and cannot be removed, but the electrode is configured separately and is appropriately attached to the mounting hole on the frame side at the time of use. It may be a simple configuration.
The material of the electrode body 34 in the above embodiment may be made of a metal (or plating) such as gold, silver, or platinum, for example, as long as it is a material having good conductivity other than the above-mentioned brass. It may be other than metal.
-It is free to implement in other modes that do not depart from the spirit of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Headset as a head mounting apparatus, 21A ... Base part as 1st part, 21B ... Fork part as 2nd part, 21 ... 1st frame as a frame, E1-E8 ... As receiving member Electrodes.

Claims (20)

In the head-mounted device that acquires the brain activity signal through the receiving member that is mounted on the head and receives the brain activity signal,
A frame arranged along the shape of the head, the frame having a first portion arranged at the back of the head and a second portion extending from the first portion along the side of the head. And
At least two receiving members are disposed on the inner surface of the first portion, and the receiving members constitute a receiving member row disposed in series along a surface orthogonal to the median head surface;
The second portion is configured to have an elevation angle forward with respect to a first virtual plane formed around the head passing through three points of the occipital nodule and the left and right anterior pinna. A head-mounted device for detecting brain activity. The receiving member row is arranged so as to exist on a second virtual plane that is parallel to the first virtual plane and not below the first virtual plane,
The head-mounted device for detecting brain activity according to claim 1, wherein the second part is configured to have an elevation angle forward with respect to the second virtual plane.   3. The head-mounted device for detecting brain activity according to claim 1, wherein the second part extends from the first part along the left and right head side surfaces.   The head-mounted device for detecting brain activity according to any one of claims 1 to 3, wherein the receiving member row is arranged at a position adjacent to the first virtual plane.   5. The device according to claim 1, wherein the second portion passes through a boundary region between the side and top of the wearer and reaches the forehead in a state where the frame is disposed on the head. A head-mounted device for detecting brain activity according to claim 1.   6. The head-mounted device for detecting brain activity according to claim 1, wherein the receiving member is arranged so as to be line-symmetrical at the center position of the entire length of the receiving member row.   7. At least a part of the frame has elasticity, and a biasing force that returns to the inside is generated by pushing the second portion outward in a direction away from the head. A head-mounted device for detecting brain activity according to any one of the above.   The head mounting device for detecting brain activity according to any one of claims 1 to 7, wherein a contact area to the frontal region is provided in the second part.   9. The head mounting device for detecting brain activity according to claim 8, wherein the frame is supported with respect to the head by the receiving member and the contact area.   The head mounting device for detecting brain activity according to any one of claims 1 to 9, wherein a weight member is disposed in the first portion.   The head mounting device for detecting brain activity according to claim 10, wherein the weight member is housed in a housing portion formed in the first portion.   The head mounting for brain activity detection according to any one of claims 1 to 11, wherein the second part extends from both sides of the first part in a pair of left and right along the side of the head. apparatus.   The head-mounted device for detecting brain activity according to any one of claims 1 to 12, wherein the elevation angle is 15 to 60 degrees.   The brain activity detection device according to claim 1, further comprising one or more second frames that connect the second parts and are arranged along a head shape. Head mounted device.   The head-mounted device for detecting brain activity according to claim 14, wherein at least one of the second frames is disposed on the forehead in a mounted state.   16. The head-mounted device for detecting brain activity according to claim 14, wherein one or more receiving members are disposed on an inner surface of the second frame.   17. The head-mounted device for detecting brain activity according to claim 1, wherein the receiving member is an electrode, and the brain activity signal is an electroencephalogram.   18. The head-mounted device for detecting brain activity according to claim 1, wherein the receiving member is an element for detecting a change in magnetic field, and the brain activity signal is a brain magnetic field. .   The near position of the said receiving member is equipped with the near-infrared light transmission part, The said receiving member is a near-infrared light-receiving part, The said brain activity signal is cerebral blood flow, The 1st-18 characterized by the above-mentioned. A head-mounted device for detecting brain activity according to any one of the above.   A brain activity measurement system that measures brain activity based on a brain activity signal obtained by the head-mounted device for detecting brain activity according to any one of claims 1 to 19.

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