Brain activity measuring device and brain activity measuring system

Abstract

To provide a brain activity measuring device and a brain activity measuring system free from tightening on to the temporal region by a frame, which hardly gives uncomfortable feeling when mounted.SOLUTION: An elastic cushion body 13 that is self-supported from a connector 5 of a frame body 2 and is erected inwardly is disposed inside the frame body 2 mounted on the head of a headset, and an electrode 15A to abut against the head through a connection sheet 16 is disposed on an apex 13c of the cushion body 13. The tip of a swing part 16B is fixed to a second part 2B of the frame body 2 when a part sticking out sideways from the cushion body 13 of the connection sheet 16 is represented as the swing part 16B. The swing part 16B is installed between the end of the cushion body 13 and the inside of the second part 2B of the frame body 2, and the electrode 15B is disposed in the swing part 16B.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a brain activity measuring device and a brain activity measuring system used for measuring brain activity. [Background technology]

[0002] Measurement of brain activity and its use have become more common with the development of non-invasive brain activity imaging technology. Representative (common) methods for non-invasive brain activity imaging at present include, for example, functional magnetic resonance imaging (fMRI), magnetoencephalograph (MEG), functional near infrared spectroscopy (fNIRS), and electroencephalogram (EEG). fMRI and MEG are large devices, and although they have high analytical capabilities, they require special laboratory environments such as magnetically shielded rooms, and the cost of the devices and maintenance is also high. Because they are large devices, measurements are generally taken with the subject's head fixed inside the device, so the subject is required not to move his or her head at all during the measurement. During the measurement, positioning markers may be attached to the subject, but generally, such devices can perform measurements without directly attaching detection elements to the subject's head. fNIRS and EEG are medium to small sized devices that can perform measurements in normal environments and some devices can be carried around, and there is great expectation for them in the industrial field because they can be mass-produced, miniaturized, and simplified. In addition, they have the characteristic that they can perform measurements even if the subject moves to some extent. These devices do not fix the subject's head inside the device as in large devices, but instead attach elements for detecting brain activity directly to the subject's head. When attaching elements for detecting brain activity directly to the subject's head, they are generally attached using a head cap or headset. In recent years, research and development has been progressing on the miniaturization and simplification of large-scale equipment such as fMRI and MEG, as well as on measurement technology for use in normal environments. When the equipment becomes medium to small sized, technology will be required to attach detection elements directly to the subject, rather than fixing the subject's head inside the equipment. When directly attaching an element for detecting brain activity to the subject's head, it is necessary to directly abut the detection element (e.g., an electrode, a light receiving part, a light emitting part, a magnetic field detection element) on the scalp. For example, when a detection element is abutted against the scalp in EEG or fNIRS, if the abutment against the scalp is too strong, the subject feels pain, and if it is too weak, noise increases during measurement, so it is necessary to adjust the abutment so that the detection element abuts against the scalp with just the right amount of pressure. In addition, when a detection element is abutted against the scalp in MEG, the distance between the detection element and the scalp must be kept as constant as possible because the magnitude of the magnetic field signal changes significantly depending on the distance between the element and the scalp. Head shapes vary greatly depending on age (e.g., child or adult), sex (male, female), race (e.g., Japanese or Western), height, body type, etc., and even within the same age, sex, and race, there are large individual differences, and differences such as a flat-headed shape at the back of the head or an egg-shaped shape must also be taken into consideration. In academic brain science experiments, head caps and other devices are used and the contact of each detection element is adjusted to suit the subject, but this is a lot of work. Therefore, particularly in industrial applications and in academic research, there is a demand for head-mounted devices for detecting brain activity that are as simple in structure as possible and easy to handle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-221144 A [Patent Document 2] JP 2019-063290 A Summary of the Invention [Problem to be solved by the invention]

[0004] For example, there is a head-mounted device for detecting brain activity as shown in Patent Document 1. The technology of Patent Document 1 has an approximately semicircular outer shell, a band-shaped body having electrodes, and a plurality of first elastic bodies, and one end of each of the plurality of first elastic bodies is connected to both ends of the outer shell, so that the device can be fitted to various shapes of people's heads. In this configuration, the outer shell and the band-shaped body having electrodes are combined to realize the device can be fitted to various shapes of people's heads, but since both ends of the band-shaped body are connected to the outer shell, the band-shaped body hangs down when the device is worn, and it is necessary to lift it up by hand and fix it, which is a problem that it is difficult to use. In addition, since the head is sandwiched between the outer shell frame when worn, it is assumed that the outer shell frame needs to be made strong, and there is a problem that the degree of freedom in designing the device is low. In other words, there are problems with the practicality of the device as a device, ease of handling, and degree of freedom in designing the device. In addition, there are problems with the conventional technology in that a head-mounted device for detecting brain activity can be realized with both a simple structure and an easy-to-handle structure.

[0005] In order to solve such problems, the applicant developed the brain activity measuring device of Patent Document 2. The first embodiment of the brain activity measuring device of Patent Document 2 is a headset 1 configured by combining a first frame body 2 and a second frame body 3 so that they cross each other. When wearing the headset, the first frame body 2 is spread out and placed at the back of the head, and the second frame body 3 is placed at the front of the head, so that the cushion body 13 is elastically abutted against the head. Therefore, it is possible to provide a brain activity measuring device that is easy to use and solves the problems of Patent Document 1. However, even though such an improved brain activity measuring device has been provided, several problems still remain, as described below. (1) In the case where there is a demand to measure brain activity in the temporal region, for example, if electrodes are attached to the frame of a brain activity measuring device as described in Patent Documents 1 and 2 that faces the temporal region, there is a high possibility that not only the electrodes but also the frame will come into contact with the temporal region, which will cause discomfort when the frame is worn. (2) There is a demand to measure the brain activity of infants and young children, but since the scalp of infants and young children is particularly soft, it is necessary to avoid the frame touching the head or the electrodes attached to the frame digging into the head. In addition, infants and young children may dislike the frame touching them. This makes it difficult to measure brain activity in the temporal region of infants and young children with a device like (1). The scalp of elderly people can also be delicate, so the same is true. (3) In the brain activity measuring device as disclosed in Patent Document 1, if the first elastic body is not tightly fastened, it will sag from the outer shell of the frame. Such fastening is particularly burdensome for infants and small children. [Means for solving the problem]

[0006] In order to solve the above problem, a first means includes a frame member to be placed on the head, the frame member having a first portion located in the center and a pair of left and right second portions located so as to extend rearward from both left and right ends of the first portion with the first portion at the front, and an elastic support body arranged inside the first portion of the frame member and rising inward independently from the first portion, the support body being configured to be pushed by the head and deformed as the frame member is placed on the head, and a pair of left and right strips having one or more electrodes attached thereto are erected with one end fixed to the support side and the other end fixed to the second portion side, and the strips are attracted to the support when the support body deforms, causing the electrodes to move inward from the frame member side. As a result, when the frame member is placed on the head, the support body is pressed by the head and deformed, and the strip body is attracted to the support body and moves inward from the frame member side, so that even if the frame member is formed wide so that the head does not come into contact with it, the electrodes attached to the strip body can be brought into contact with the temporal region. In particular, since the frame member does not come into contact (or is unlikely to come into contact with) when measuring brain activity in the temporal region, there is no sense of tightness from the frame member, and it is suitable for infants, small children, and small children.

[0007] Here, "brain activity" refers to biological activity that can generally be measured as a magnetic field (magnetic field) associated with neural activity in the brain, a potential difference (voltage difference) at different points on the scalp, or a difference in the amount of near-infrared light absorbed by oxygenated hemoglobin and deoxygenated hemoglobin. The "frame member" is a base that is attached to a person's head, and there are no limitations on the material or shape. The frame member has a first part that is arranged in the center, and a pair of second parts that are arranged so as to extend backward from both the left and right ends of the first part, with the first part in front. The head is surrounded by these first and second parts. Therefore, it is preferable that the frame member has a shape and function that does not easily fall off the head. For example, it is preferable that the frame member can be made to hold the head or to cover the head. The frame member may be made of, for example, plastic, rubber, wood, or metal. In this case, it is not necessarily necessary to hold the head directly with the frame member. The "support" is disposed inside the frame member, but as long as it is disposed inside, it may be fixed directly to the frame member or fixed via another member. The material and shape of the support are not limited as long as it can stand up inward independently and has elasticity, and an electrode can be placed on the top. The support serves as a scalp shape following part that follows the shape of the head. In other words, the support is configured to be pushed by the head and deformed. "Inward" refers to the head direction when the brain activity measuring device is worn. In addition, it is preferable that there is a cavity inside to wire the electrodes, but it is not necessary. The material is preferably one that can stand on its own and have elasticity, such as synthetic resin materials or rubber materials such as silicone, elastomer, polyurethane, polyethylene, and foam sponge. "Standing on its own" means that when the device is held in the air by hand, the support does not deform due to gravity, or the amount of deformation is very small. This eliminates the need for the wearer (including the subject) to hold the support when the device is attached to the subject, or to lift the support when it sags due to gravity. "Having elasticity" means that it has the property of deforming while having resilience when an external force is applied, and returning to its original shape after deformation. The elastic support will deform according to the shape of the head when the brain activity measuring device is attached, but after attaching it to the head, the degree of contact with the scalp will be automatically adjusted, and if the contact of the electrodes is strong, the force will be transmitted in the direction of moving the brain activity measuring device away from the scalp, and if the contact of the electrodes is weak, the force will be transmitted in the direction of moving the electrodes closer to the scalp. This allows the electrodes placed at the top of the support to contact with just the right degree of contact. The "strand" is installed so that one end is fixed to the support and the other end is fixed to the second part of the frame member. With this configuration, when the support is deformed, the strand is arrested by the support, and the electrode moves inward from the frame member side. The strand has a moving end that displaces according to the deformation of the support, with the fixed end fixed to the second part as a reference. The displacement of the moving end is not uniform depending on the shape of the support and the degree of contact of the head with the support, but the moving end side displaces so as to rotate inward with the fixed end as a reference. This allows the electrode to be moved toward the side of the head, and since the frame member does not move, the frame member does not come into contact with the side of the head, and the electrode can be abutted against the side of the head. In other words, the strand is long and thin. Examples of materials include synthetic resin materials such as silicone, elastomer, polyurethane, and polyethylene, and rubber materials, and may be made of plastic, wood, metal, or string such as cotton or hemp. The strand is preferably flexible, but may not be flexible. The strand is placed at a suitable position between the support and the second part of the frame member. The attachment position of the strand to the second part side may be changeable. The strip may be provided with slits or the like so that the length of the strip changes with the deformation of the support. Also, slits may be formed in the strip at the positions where the electrodes are attached, making it possible to change the positions of the electrodes.

[0008] The "electrodes" are, for example, electrodes for electroencephalography that measure changes in electric current (changes in potential difference) associated with neural activity in the brain, electrodes (elements) for measuring magnetic fields (cerebro-magnetic fields) that measure changes in electric current associated with brain activity as changes in magnetic fields, and probes (light-receiving probes and light-emitting probes) for near-infrared spectroscopy that measure changes in cerebral blood flow (oxygenated hemoglobin, deoxygenated hemoglobin, etc.) associated with brain activity as changes in the amount of near-infrared light received. The electrodes are often placed symmetrically with respect to the median plane connecting the root of the nose, the parietal region, and the occipital tubercle, and the "temporal region" refers to electrode positions at T3 and T4 (T7 and T8 in the international 10-10 electrode system) or nearby in the international 10-20 electrode system, i.e., near FT9, T9, TP9, FT7, TP7, FC5, C5, CP5, FT10, T10, TP10, FT8, TP8, FC6, C6, and CP6 in the international 10-10 electrode system. In particular, when recording brain activity as potential difference (voltage difference) (electroencephalography), dry electrodes are preferable because they can reduce the burden of measurement on the subject. In addition, it is preferable to place a preamplifier near the dry electrodes because it can reduce measurement noise. As dry electrodes, metal electrodes whose surfaces are plated or coated with gold, silver, or silver / silver chloride, conductive resins containing carbon, silver particles, and silver fillers, resin electrodes using conductive organic materials, etc. are preferably used, but the material and shape are not limited. In order to avoid the influence of hair when worn, the electrodes should have a shape with a certain height and area. The "brain activity measuring device" is a "head-mounted device" for detecting brain activity. The head-mounted device may or may not have built-in circuits such as a differential amplifier and communication circuits, and a battery. In addition, "mounted" does not mean that the frame member is in direct contact with the head, and the frame member may or may not be in contact with the head as long as it is placed on the head.

[0009] As a second means, one or more electrodes are attached to the support. This allows information on brain activity to be obtained from the support, and the support can be configured so that the electrodes do not come into contact with the scalp (or are difficult to come into contact with the scalp) because they come into contact with the scalp. In this case, it is preferable that one or more electrodes are attached to the support at a position that faces the subject's scalp when worn on the subject, in order to make the electrodes contact the subject with an efficient force, and it is particularly preferable that they are attached to the front end of the support. The electrode is preferably at the front end of the support. The "front end" is the inside of the frame member, the side that is pressed by the head. It is better to have multiple electrodes for evaluating the laterality of the brain, and it is preferable that they are arranged symmetrically with respect to the median plane connecting the subject's nose root, parietal, and occipital tubercle. It is particularly preferable that the number of electrodes is 2, 3, 4, or 5, which can be arranged symmetrically (and also on the median plane if the number is odd). As a third means, a contact member having a surface that comes into contact with the head side is formed between the support body and the electrode. The electrode at the top of the self-supporting support usually has a certain area and height (distance from the tip of the electrode to the support). When the wearer (including the subject himself) puts the brain activity measuring device on the subject, if the reaction force from the subject's head to the electrode is transmitted diagonally or horizontally (the direction in which the electrode falls) with respect to the height direction of the electrode, the support may bend when the brain activity measuring device is put on, and the electrode may fall. With this configuration, when the brain activity measuring device is put on the head, the "surface" of the contact body comes into contact with the "surface" formed by the scalp, hair, etc. on the head side as the electrode is put on the scalp, so that it is possible to prevent a large force from being applied in the direction in which the electrode falls, and to prevent the electrode from falling. In addition, the "contact body" comes into contact with the "surface" formed by the scalp, hair, etc. on the head side from various directions to distribute the reaction force, and it is possible to prevent unnecessary deformation caused by, for example, a part of the electrode being strongly pushed back against the scalp during the putting on operation. The "contact body" serves to prevent the electrode from collapsing, and also appropriately adjusts the amount of deformation of the support. Since it is unknown in what direction and in what orientation the subject or wearer (operator) will wear the brain activity measuring device on his / her head, the abutment body is not necessarily formed only in a position close to the electrode. For example, the abutment body may be formed on a side of the support body that is quite far from the electrode. There may be multiple abutment bodies. The interpretation of the abutment body is the same in the following explanation. "Having a surface that abuts on the head side" does not mean that all of the abutment bodies have to abut on the head side, but rather that the abutment body must have a surface that has the function of preventing unnecessary deformation of the support body. The contact body may be made of the same material as the support body or a different material. Regardless of the material, the contact body and the support body may be molded integrally by two-color molding or the like. Alternatively, the contact body may be in the form of a sheet and sandwiched between the support body and the electrode or between the support bodies. The material of the contact body may be, for example, a synthetic resin material such as silicone, elastomer, polyurethane, polyethylene, or a rubber material. By changing the molding conditions or shape, it is possible to make it elastic or non-elastic, and there is no particular limitation on the material. In addition, by increasing the area of ​​the contact body, it is possible to increase the area that receives the reaction force when pressed against the head.

[0010] As a fourth means, one end of the strip is connected to the abutment body. In other words, the strip is formed as a separate body from the contact body, and one end side of the strip is indirectly fixed to the support body via the contact body. As a fifth means, the strip is a part of the abutment body. In other words, this is a case where the strip is a part of the abutment body and one end side is indirectly fixed to the support body via the abutment body. By configuring it in this way, it is not necessary to directly attach the strip to the support, and it becomes easy to configure the strip from a material different from the support. It is also possible to design the strip so that its length can be changed by providing slits in the strip, for example. As a sixth means, the contact body is made of a material that does not stretch. As a result, when the support is subjected to a force that deforms the head side by contacting the head side during the wearing operation, for example, by being pushed through the contact body, the force is transmitted without escaping, so that the reaction force when the head side is contacted from various directions can be dispersed to the other support side. The material of the contact body is preferably a synthetic resin material such as polyurethane, polyethylene, polypropylene, etc. The contact body may be molded separately from the support body or integrally with it. The "non-stretchable material" does not mean a material that does not stretch at all, but may have some elasticity as a material characteristic. If the material stretches too much, the electrode may not be able to properly contact the scalp, so the deformation rate of the material is preferably 15% or less, and more preferably 5% or less. As a seventh means, the strip is made of a non-stretchable material. In other words, it is to prevent the arresting force from escaping when the support is deformed by being flexible but not stretching like a rubber band. The strip may be configured straight or bent or curved. In addition, it is good to make cuts above and below or to the left and right of the electrode at the position where the strip is attached, because this makes it easier for the electrode to follow the scalp. As an eighth means, the frame member is configured such that when the frame member is placed on the head, the second portion does not come into contact with the head, and one or more electrodes attached to the strip come into contact with the head. This is because it is preferable that the frame member does not come into contact with the head when placed on the head (particularly the temporal region), as this improves the comfort when wearing the brain activity measuring device. Also, when a feeling of tightness is a problem when wearing the brain activity measuring device, such as in the case of infants and small children, it is preferable that the frame member does not come into contact with the head, as this can reduce the feeling of tightness.

[0011] As a ninth means, the frame member is arranged so that the first portion crosses the forehead, and brain information of the forehead is acquired by the one or more electrodes of the support. This makes it possible to provide a brain activity measuring device that simultaneously detects brain information from the frontal region and brain information from the temporal region. In addition, since there is no first portion on the back of the subject's head, brain activity can be measured even if the subject is in a supine position. In order to measure the difference in brain function between the left and right, it is preferable that there are multiple electrodes, and they are equally arranged on the left and right sides with Fpz or AFz in the international 10-10 electrode system as the center. For example, when Fpz is the center, if there are two electrodes, they are arranged as Fp1 and Fp2 in the international 10-20 electrode system, if there are three electrodes, they are arranged as Fp1, Fpz, Fp2 in the international 10-10 electrode system, if there are four electrodes, they are arranged as F7, Fp1, Fp2, F8 in the international 10-20 electrode system, and if there are five electrodes, they are arranged as AF7, Fp1, Fpz, Fp2, Af8 in the international 10-10 electrode system, and so on. When adopting an electrode arrangement with more electrodes than the international 10-10 electrode system (i.e., the distance between the electrodes is closer), the number of electrodes may be 5 or more. The electrode arrangement is one example and is not limited to this. As a tenth means, the frame member is arranged so that the first portion crosses the top of the head, and brain information of the top of the head is acquired by the one or more electrodes of the support. This makes it possible to provide a brain activity measuring device that simultaneously detects brain information from the parietal region and the temporal region. In addition, since the first portion is not located on the frontal or occipital regions of the subject, brain activity can be measured even if the subject is in a supine or prone position. In order to measure the difference in brain function between the left and right brain, it is preferable that the number of electrodes is multiple, and that the electrodes are equally arranged around Cz in the international 10-10 electrode system. For example, if the number of electrodes is 2, the electrodes are arranged as C3 and C4 in the international 10-20 electrode system; if the number of electrodes is 3, the electrodes are arranged as C3, Cz, and C4 in the international 10-20 electrode system; if the number of electrodes is 4, the electrodes are arranged as C3, C1, C2, and C4 in the international 10-10 electrode system; and if the number of electrodes is 5, the electrodes are arranged as C1, C2, Cz, C3, and C4 in the international 10-10 electrode system. The electrode arrangement is an example and is not limited thereto. As an eleventh means, the frame member is arranged so that the first portion crosses the back of the head, and brain information at the back of the head is acquired by the one or more electrodes of the support. This makes it possible to provide a brain activity measuring device that simultaneously detects brain information from the occipital region and the temporal region. In addition, since there is no first portion on the frontal region of the subject, it is possible to measure brain activity of the subject in a prone position. In order to measure the difference in brain function between the left and right brain, it is preferable that there are multiple electrodes, and they are equally arranged around Oz in the international 10-10 electrode system. For example, if there are two electrodes, they are arranged at O1 and O2 in the international 10-20 electrode system; if there are three electrodes, they are arranged at O1, Oz, O2 in the international 10-10 electrode system; if there are four electrodes, they are arranged at T5, O1, O2, T6 in the international 10-20 electrode system, or PO7, O1, O2, PO8 in the international 10-10 electrode system; if there are five electrodes, they are arranged at PO7, O1, Oz, O2, PO8, or P7(T5), O1, Oz, O2, P8(T6) in the international 10-10 electrode system. It is also possible to combine the frame members of the ninth to eleventh means to simultaneously obtain brain information from different parts of the brain.

[0012] As a twelfth means, a belt member is provided, the both ends of which are fixed to the second portions on the left and right sides of the frame member, and the belt member is stretched between the second portions. By disposing the belt member between both ends of the second portion of the frame member in this manner, it becomes possible to stably attach the frame member to the head. As a thirteenth means, the belt member is fixed to the second parts on the left and right sides of the frame member and is positioned so as to intersect with the tip-side regions of the second parts, and the tip-side regions of the second parts are positioned outside the belt member. With this configuration, the frame member is not pressed down from the outside by the belt member, and the area near the tip of the second part of the frame member does not come into contact with the head, improving the comfort of use. It is also suitable for people who do not like the frame member coming into direct contact with the scalp, such as infants, small children, and the elderly. As a fourteenth means, one or more electrodes are attached to the belt member. This allows brain information to be obtained from the belt member as well, so that information on various positions on the head can be obtained simultaneously with brain information from the electrodes on the frame member side depending on the mounting position of the frame member. In addition, the head is encircled by the first part of the frame member, the pair of second parts on the left and right, and the belt member, so that the electrodes can be evenly arranged along the head circumference, for example, Fp1, Fp2, T3, T4, O1, and O2 in the international 10-20 electrode system. Evenly arranging the electrodes is useful when comparing the functions of the left and right brain hemispheres.

[0013] As a fifteenth means, the frame member has legs to which the left and right second portions are respectively connected, and when both ends are connected to the left and right legs, the frame member can be raised by the legs so that the first portion is positioned upward, and a belt member is stretched between the left and right legs. By attaching legs to the second parts on the left and right sides of the frame member of the brain activity measuring device, the frame member can be raised so that the first part is positioned upward, and the head of a subject (especially an infant or young child) in a lying position (such as supine) can be placed on the belt member stretched between the left and right legs so as to be worn. As a sixteenth means, one or more electrodes are attached to the belt member stretched between the leg portions. Such a belt member can obtain brain information from the back of the head. For example, if electrodes are provided on the frame member, brain information from the frontal electrodes and information from the back of the head can be obtained at the same time. In order to measure the left and right brain functions, it is preferable to have multiple electrodes, but in cases where it is desired to compare the activity of the frontal and back of the head, only one electrode may be attached to the belt member.

[0014] As a seventeenth means, a slit is formed in the strip, and the one or more electrodes are attached so as to be movable along the longitudinal direction of the slit. If the electrode can be moved along the longitudinal direction of the slit in this way, it becomes possible to change the position of the electrode as appropriate according to the size of the subject's head circumference, i.e., the position of the temporal region. In the present invention, the concept of "slit" also includes a long hole having a certain width.

[0015] Also, as an eighteenth means, there is provided a brain activity measuring system for measuring brain activity, which measures brain activity based on a brain activity signal obtained by the brain activity measuring device according to any one of the first to nineteenth means. Also, as a nineteenth means, there is provided a brain activity measuring system for measuring brain activity, which measures brain activity based on an electroencephalogram signal obtained by the brain activity measuring device of any one of the first to nineteenth means. By doing so, it is possible to provide a brain activity measurement system that reduces the effort of attaching electrodes to the wearer (subject), and shortens the measurement preparation time. The "brain activity measurement system" may include, for example, a "head-mounted device", a circuit unit built into (or externally connected to) the head-mounted device, a recording device (computer, tablet, mobile phone, etc.) that records brain activity data from the circuit unit through wireless or wired communication, recording software that records brain activity data inside the device, and brain activity analysis software that analyzes brain activity data. In addition, in order to obtain temporal synchronization between external stimuli and measurement data, the "brain activity measurement system" may include, for example, transmission of a trigger signal associated with an external stimulus, and reception of a trigger signal by a circuit unit built into (or externally connected to) the head-mounted device or a recording device. As the "brain activity", for example, electroencephalogram (EEG), cerebral blood flow (fNIRS), and magnetic field of the brain (MEG) may be measured, and in particular, the present invention may be applied to a brain activity measurement system using dry electrodes. In addition, the present invention may be applied to a wet-type electroencephalogram measurement system using gel, saline, paste, etc. in electroencephalogram measurement. The above-mentioned inventions of the first to nineteenth means can be arbitrarily combined. In particular, it is preferable to have the configuration of the first means and to have a combination with at least one of the configurations of the inventions of the second to nineteenth means. Any component of the inventions of the first to nineteenth means may be extracted and combined with another component. Effect of the Invention

[0016] In the above invention, when the support body is pressed by the head and deformed, the strip is attracted to the support body and moves inward from the frame member side, so that even if the frame member is formed wide so that the head does not come into contact with it, it is possible to bring the electrode attached to the strip into contact with the side of the head. [Brief description of the drawings]

[0017] [Figure 1] 2 is a perspective view showing the inside of a frame body of the headset according to the first embodiment with a head belt not attached. FIG. [Diagram 2]FIG. 4 is an explanatory diagram for explaining a schematic internal structure of the frame body side in a state where a head belt is not attached in the first embodiment. [Diagram 3] FIG. 2 is a partially omitted plan view of the headband according to the first embodiment. [Figure 4] FIG. 4 is an explanatory diagram illustrating a structure near an end of the headband according to the first embodiment. [Diagram 5] FIG. 1 is a plan view of a headset according to a first embodiment. [Figure 6] FIG. 2 is an explanatory diagram illustrating a state in which the headset according to the first embodiment is used. [Figure 7] 5A and 5B are explanatory diagrams showing a state before and after the head is brought relatively close to the frame body and brought into contact with the electrodes in the headset of the first embodiment; [Figure 8] 13A is a perspective view of a case used in a headset according to a second embodiment, and FIG. [Figure 9] FIG. 11 is an explanatory diagram illustrating a state in which a headset according to a second embodiment is used. [Figure 10] 13A and 13B are explanatory diagrams illustrating a structure near an end of a headband according to a second embodiment. [Figure 11] 13A and 13B are explanatory diagrams illustrating a process of attaching a headband to a headset according to a second embodiment, in which FIG. [Figure 12] 13A and 13B are explanatory diagrams illustrating a state in which a headset according to another embodiment is used. [Figure 13] FIG. 13 is an enlarged perspective view showing the vicinity of a swinging portion of a connecting sheet in an internal structure on the frame body side in another embodiment. [Figure 14] 13A and 13B are explanatory diagrams illustrating a method for fixing the ends of a headband in another embodiment. [Figure 15] FIG. 2 is an explanatory diagram of an electrode arrangement according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. (First embodiment) In this embodiment, an electroencephalogram measuring system including electrodes 15, which are dry electrodes made of conductive resin of urethane material, will be described as an example. The device of this embodiment has electrode positions FT7, Fp1, Fp2, FT8, O1, and O2 in the international 10-10 electrode system shown in Figure 15, and is worn as shown in Figure 6. As shown in Figures 1, 2, 5, 7, etc., a headset 1 serving as a brain activity measuring device includes a frame body 2 serving as a frame member that is hollow and curved so as to be convex outward as a whole. The frame body 2 is made of a plastic material, specifically, a polyurethane material as an example here. The frame body 2 is hard and inelastic, but has some flexibility as a whole. The frame body 2 is a member having an overall horseshoe-shaped appearance, and comprises a first portion 2A located toward the center, curved so as to convex outward and positioned on the forehead, and a second portion 2B formed integrally on both the left and right sides of the first portion 2A and positioned on the sides of the head. The frame body 2 is configured such that the first portion 2A is wider in the vertical direction, and the second portion 2B is narrower in the vertical direction than the first portion 2A. The second portion 2B is gradually tapered toward the rear end (open end side). The second portion 2B has flexibility that allows it to swing inward and outward with the first portion 2A as a base. When the second portion 2B is expanded outward, a biasing force is generated as internal energy, and the second portion 2B, which is released from the constraint by the biasing force, automatically returns to its original shape. As shown in FIG. 1, a first tape 9 having many small hooks affixed thereto is attached to the outer surface of the second portion 2B. The first tape 9 cooperates with a second tape 27, which will be described later, to form a hook-and-loop fastener.

[0019] A connector frame 5 is disposed on the inner surface of the first portion 2A of the frame body 2. As shown in Figs. 1 and 2, the connector frame 5 is a sub-frame body attached to the frame body 2, which has a generally crescent-shaped appearance with a convex outer surface corresponding to the concave inner surface shape of the first portion 2A of the frame body 2. The connector frame 5 is made of the same material as the frame body 2 and is a hard body. A plurality of locking claws 8 are formed on the periphery of an opening 7 of the connector frame 5. As shown in Fig. 2, when the opening 6 of the frame body 2 and the opening 7 of the connector frame 5 are aligned with each other, the locking claws 8 of the connector frame 5 advance into the opening 6 of the frame body 2 and engage with the edge of the opening 6, and the connector frame 5 is fixed to the inner surface of the frame body 2 by this action. The connector frame 5 can be attached to and detached from the frame body 2 by engaging and disengaging the locking claws 8. A differential amplifier 10, a communication circuit 11, a storage battery 12, and the like are housed in the connector frame 5. The electrical configuration of these components will be described in detail later. One cushion body 13 serving as a support is fixed by an adhesive to the inner surface (front surface) of the connector frame 5. The means for fixing the cushion body 13 does not necessarily have to rely on an adhesive, and for example, it may be fixed by a connecting structure similar to that of the opening 7 of the connector part 5 and the locking claw 8, or may be fixed by a screw. The cushion body 13 is disposed facing the inner surface of the headset 1 via the connector frame 5. The cushion body 13 is a bag-shaped hollow body made of silicone, and is an elastic body that is fixed and self-supported with the opening side of the hollow body along the curved surface of the inner surface of the connector frame 5. The cushion body 13 has an overall block-like appearance that is horizontally elongated in the direction of the second part 2B on the left and right sides of the frame body 2 with a certain vertical width. The cushion body 13 is composed of a bottom part 13a having a circuit-shaped outer contour with a long straight line part that contacts with an inverse curved surface along the curved surface of the inner surface of the connector frame 5, a wall part 13b that rises from the entire periphery of the bottom part 13a, and a top part 13c that closes the top of the wall part 13b. The top part 13c is composed of two surfaces (a first surface 13A and a second surface 13B) that are at different angles. The first surface 13A is configured so that the central region extends flat in the horizontal direction, which is the chord direction of the curved frame body 2, and the second surfaces 13B are arranged on both the left and right sides of the first surface 13A and are configured to be inclined relative to surface 13A so that these surfaces face inward. 2, a preamplifier 14 is disposed on the rear surface of the top portion 13c within the cushion body 13. The preamplifier 14 is formed into a flat washer-like shape. The fixing means and electrical configuration of the preamplifier 14 will be described in detail later.

[0020] As shown in Figs. 1, 2, 5, 7, etc., a single connecting sheet 16 is disposed on the top 13c of the cushion body 13, and a plurality of electrodes 15 (four in this embodiment) are disposed along the longitudinal direction of the connecting sheet 16. The connecting sheet 16 as the contact body is a thin plate made of a non-stretchable and flexible plastic material, specifically, here, it is made of a polycarbonate material as an example. The connecting sheet 16 is formed to be longer than the width of the cushion body 13, and is formed to be bent along the shape of the first surface 13A and the surface 13B of the top 13c of the cushion body 13, and both ends are extended and formed to protrude laterally from the top 13c of the cushion body 13. The part of the connecting sheet 16 that is fixed and adhered to the cushion body 13 is called the adhered part 16A, and the part that protrudes laterally from the cushion body 13 is called the swinging part 16B. The contact portion 16A is disposed on the top portion 13c along the longitudinal direction of the top portion 13c, and completely covers the top portion 13c. The contact portion 16A is in contact with the first surface 13A and the surface 13B of the top portion 13c. The swinging portion 16B is a strip-shaped member that extends from the contact portion 16A to the side while being bent so as to be gently convex outward so as to substantially follow the inner wall of the second portion 2B of the frame body 2. The tip of the swinging portion 16B is fixed to the inner wall of the second portion 2B of the frame body 2 by a screw 20. As a result, the swinging portion 16B is installed between the end of the cushion body 13 and the inside of the second portion 2B of the frame body 2. The swinging portion 16B swings against the inner wall in the vicinity of the inner wall of the second portion 2B of the frame body 2 in response to the bending of the cushion body 13, and moves toward and away from the inner wall.

[0021] The electrode 15 is composed of a disk-shaped main body 17, a protrusion 18 as a grounding portion, and a support shaft (not shown) that protrudes downward from the center of the main body 17. A male screw is formed on the outer periphery of the support shaft, and the electrode 15 is fixed to the preamplifier 14 by the male screw and a fastening member such as a nut (not shown). The electrode 15 transmits electrical information from the protrusion 18 to the preamplifier 14 via the support shaft. The protrusion 18 has multiple (here, 12) protrusions that are implanted to be rotationally symmetrical, and the protrusion tips of the protrusions 18 are intended to abut against the scalp. Of the four electrodes 15, two are disposed in the contact portion 16A and two are disposed in the swinging portion 16B. The electrode 15 disposed in the contact portion 16A is referred to as electrode 15A, and the electrode 15 disposed in the swinging portion 16B is referred to as electrode 15B. The electrode 15A disposed in the contact portion 16A is fixed to the top portion 13c (first surface 13A) of the cushion body 13 via a washer 21. A preamplifier 14 (not shown) is disposed inside the cushion body 13 (the back surface of the first surface 13A), and is fixed by a fastening member in a state in which a support shaft (not shown) of the electrode 15A is engaged with the preamplifier 14. Electrode 15B arranged on oscillating portion 16B of connecting sheet 16 is fixed at a predetermined position in a long hole 19 formed in oscillating portion 16B with preamplifier 14 arranged on the back surface. Long hole 19 extends at a constant width along the longitudinal direction of oscillating portion 16B. With preamplifier 14 arranged on the back surface of oscillating portion 16B, electrode 15B is fixed by a fastening member with a support shaft (not shown) of electrode 15A extending to the back surface side of oscillating portion 16B so as to intersect with long hole 19 and engaged with preamplifier 14. The electrode 15A attached in this manner changes its position as the contact portion 16A follows the bending of the top portion 13c in response to the bending of the cushion body 13. In addition, the electrode 15B moves together with the swinging portion 16B when it swings toward or away from the inner wall of the second portion 2B of the frame body 2.

[0022] Next, the head belt 25 that is used together with the frame body 2 to constitute the headset 1 will be described. As shown in Figs. 3 to 6, the head belt 25 as a belt member is a strip made of synthetic rubber having elasticity, some stretchability, and flexibility. The head belt 25 has a long rectangular parallelepiped shape as a whole, and has windows 26 as rectangular openings formed near both ends. A second tape 27 having a large number of small loops planted therein is attached to the inner surface near the end from the window adjacent to the window 26. Two electrodes 15C are attached at a distance from each other at the center of the head belt 25. The two electrodes 15C have protrusions 28 of a different shape from the electrodes 15A and 15B. The protrusions 28 are so-called button electrodes formed in a dome shape with a smooth rise near the center as a whole. The electrodes 15C are fixed at a predetermined position of a long hole 29 formed in the head belt 25 with the preamplifier 14 arranged on the back side. The long hole 29 extends with a constant width along the longitudinal direction of the head belt 25. The mounting structure of electrode 15C is similar to that of electrode 15B disposed on swinging portion 16B described above, and therefore a detailed description thereof will be omitted. When the two electrodes 15C are attached as shown in Fig. 6, they correspond to O1 and O2 in the international 10-20 electrode system shown in Fig. 15. There are horizontal slits near the electrode attachment positions of the head belt 25, allowing fine adjustment of the electrode positions.

[0023] Next, an outline of the electrical configuration of the headset 1 thus configured will be described. Each of the electrodes 15A-C is electrically connected by connecting a support shaft (not shown) to the preamplifier 14. The cables 31 from the preamplifier 14 of the frame body 2 are connected to the differential amplifier 10 in the connector frame 5. The differential amplifier 10, the communication circuit 11, and the preamplifier 14 are supplied with power from a storage battery 12. A ground electrode and a reference electrode (not shown) extend from the differential amplifier 10 to the outside of the headset 1. When the device is worn, the ground electrode and the reference electrode (reference electrode) are fixed to the wearer's body, for example, the right earlobe, by clips. Each of the electrodes 15A-C is connected to the inside of the differential amplifier 10 via the preamplifier 14 and the cables 31, and the differential amplifier 10 is connected to the communication circuit 11. Note that part of the cable 31 is not shown. The preamplifier 14 is attached to each of the electrodes 15A-C and amplifies the electroencephalogram voltage acquired at that position. The differential amplifier 10 has a differential amplifier circuit, and calculates and amplifies the electroencephalogram voltage and potential difference obtained from the reference electrode (not shown). The potential data amplified by the differential amplifier 10 is wirelessly transmitted to the outside by the communication circuit 11. The potential data received by a receiving device (not shown) is output to a computer as detection target data, and the target data is recorded, displayed on a monitor screen, and analyzed.

[0024] Next, a method of using the headset 1 configured in this manner will be described. First, with reference to Figs. 7(a) and (b), the movements of the electrodes 15A and 15B when the frame body 2 is placed on the head T of the wearer will be described. As shown in FIG. 7(a), the forehead is placed directly facing the connecting sheet 16 on the front surface of the cushion body 13 in the frame body 2, and the frame body 2 is gradually brought relatively closer to the head T. At this time, there is a space between the head T and the electrodes 15B arranged on the left and right swinging parts 16B in the frame body 2. Therefore, when the frame body 2 is set on the head T of the wearer, the electrodes 15B can be set on the head T without spreading them. In addition, the electrodes 15B are unlikely to come into uncomfortable contact with the head T, such as the side of the head coming into strong contact with the electrodes 15B or the side of the head being pushed by the electrodes 15B. Even if the side of the head comes into contact with the electrodes 15B when wearing the headset, the swinging parts 16B can be swung with a small force, so that the side of the head can push the electrodes 15B outward with a very small force, and the wearer is unlikely to feel uncomfortable even if there is some contact between the head T and the electrodes 15B.

[0025] 7(a), in the state where the cushion body 13 is not pressed by the head T and keeps its original shape, the end position of the oscillating part 16B on the cushion body 13 side is designated as E1, and the end position of the frame body 2 on the second part 2B side is designated as E2. Hereinafter, these are referred to as the moving end E1 and the fixed end E2. As shown in Fig. 7(b), the front part of the head T comes into contact with the electrode 15A, and as the head T advances relatively toward the cushion body 13, the cushion body 13 is pushed through the connecting sheet 16 and bends. Following this bending of the cushion body 13, the moving ends E1 of the left and right swinging parts 16B are pulled toward the cushion body 13 and move to the position of the moving end E'1. This indicates that the moving end E1 has moved further inward (toward the first part 2A of the frame body 2) inside the frame body 2. However, since the cushion body 13 is inclined toward the left and right, depending on the degree of contact, the moving end E1 may not move toward the back. As the swinging part 16B moves from the moving end E1 to the moving end E'1 in this way, the swinging part 16B swings so as to tilt diagonally inward as a whole with the fixed end E2 as the reference. Due to this behavior of the swinging part 16B, the electrode 15B of the swinging part 16B also moves inward and comes into contact with the temporal part of the head T. This causes the electrode 15A and the electrode 15B to abut at predetermined positions on the head T. At this time, only the swinging part 16B and the electrode 15B move, so the frame body 2 does not come into contact with the head T.

[0026] 5 and 6, in order to hold the headset 1 on the wearer's head T, a head belt 25 is combined with the frame body 2. The head belt 25 is attached so as to intersect with the second portion 2B of the frame body 2, and is wrapped around the back of the wearer's head T so as to press the frame body 2 against the forehead. In this embodiment, since the head belt 25 is provided with an electrode 15C, the head belt 25 acquires information about the back of the head by the electrode 15C at the same time as fixing the headset 1. The head belt 25 is attached to the frame body 2 as follows. 5 and 6, the head belt 25 is disposed inside the second portion 2B of the frame body 2, and the tip end of the head belt 25 is crossed at a position close to the electrode 15B and disposed outside the second portion 2B of the frame body 2. The tip end of the second portion 2B of the frame body 2 is disposed outside the head belt 25 from the window 26 of the head belt 25. In other words, by crossing the frame body 2 and the head belt 25, the tip end of the head belt 25 is disposed outside the second portion 2B of the frame body 2, and the tip end of the second portion 2B of the frame body 2 is disposed outside the head belt 25. As shown in Fig. 5, the second tape 27 near the tip of the head belt 25 arranged on the outside is bonded to the first tape 9 on the second portion 2B side to form a hook-and-loop fastener, thereby fixing the head belt 25 to the second portion 2B of the frame body 2. At this time, the length is adjusted at any position within the range where the first tape 9 and the second tape 27 overlap. The headset 1 is held on the head T of the wearer by the frame body 2 and the adjusted head belt 25 surrounding the head in a ring shape. When setting the headset 1 on the wearer's head T, the head belt 25 may be attached and adjusted by, for example, first setting the frame body 2 in a predetermined position on the head T and then attaching the head belt 25 to the second part 2B. Alternatively, for example, the head belt 25 may be temporarily attached loosely to the frame body 2 at first, and after the frame body 2 is placed on the wearer's head T, the head belt 25 may be adjusted appropriately to secure the headset 1 with an appropriate fastening device.

[0027] The headset 1 of the first embodiment configured as above provides the following effects. (1) The electrodes 15B for acquiring information on the temporal region are arranged on the swinging parts 16B, and when the frame body 2 is attached to the forehead during use of the headset 1, the cushion body 13 is deflected, and the left and right swinging parts 16B are pulled toward the cushion body 13 side in response to the deflection. Therefore, when the frame body 2 is set on the head T of the wearer, the swinging parts 16B move inward and come into contact with the temporal region. Therefore, the wearer is unlikely to feel discomfort such as the temporal region coming into strong contact with the electrodes 15B or the temporal region being pressed by the electrodes 15B. In addition, there is no need to spread the electrodes 15B when wearing the headset 1, and the wearing procedure is simple. (2) Since the oscillating portion 16B is a strip that is bent and extended outwardly as part of the connecting sheet 16, it can be easily oscillated with a small force. Even if the electrode 15B comes into contact with the side of the head when the frame body 2 is set on the wearer's head T, the side of the head can push the electrode 15B outward with a very small force. Therefore, even if there is some contact between the head T and the electrode 15B, the wearer is unlikely to feel discomfort. (3) The head belt 25 is disposed inside the second portion 2B of the frame body 2, intersects with the frame body 2 near the electrode 15B, and the tip of the head belt 25 is led outward. Therefore, the frame body 2 is not exposed to the inside around the electrode 15B, and the frame body 2 will not hit the temple of the wearer. (4) The electrode 15B that contacts the side of the head can be fixed at any position in the longitudinal direction of the long hole 19 of the swinging portion 16B, and the electrode 15C that contacts the back of the head can be fixed at any position in the longitudinal direction of the long hole 29 of the head belt 25. Therefore, it is possible to arrange the electrodes 15B and 15C at optimal positions according to the size of the head T of the wearer. (5) When the electrode 15A on the frame body 2 side is brought into contact with the scalp, the connecting sheet 16 having a large area spreads around the electrode 15, so that when the electrode 15A is brought close to the forehead during the wearing operation, the scalp and hair come into contact with the connecting sheet 16 at the same time. Therefore, the electrode 15A is not the only one that receives the pressing force from the head side, but the external force is also distributed to the connecting sheet 16. Therefore, it is difficult for a defect such as a large partial dent in the cushion body 13 supporting the electrode 15A caused by only the electrode 15A being strongly pressed is unlikely to occur. The connecting sheet 16 is arranged in front of the cushion body 13 and is not connected to the frame body 2, so that it has a high degree of freedom of deformation and the external pressure on the cushion body 13 is easily distributed. In addition, since the connecting sheet 16 is a "surface", it comes into contact with the scalp surface including the wearer's hair when the headset 1 is worn, and the electrode 15A can be prevented from falling over during the wearing operation. Furthermore, since the connecting sheet 16 is connected to the frame body 2 by the cushion body 13, the connecting sheet 16 does not sag when attached, making attachment easy. (6) The connecting sheet 16 is sandwiched between the electrodes 15A in front of the cushion body 13. Therefore, the connecting sheet 16 is constructed as a set with the cushion body 13 and the electrodes 15A as a strong structure, and can generate a sufficient reaction force against the pressing force from the head side. In addition, because the connecting sheet 16 is non-elastic, when the support receives a force that is pushed and deformed through the connecting sheet 16, the force is transmitted without escaping, and the cushion body 13 can be deformed by an appropriate amount while maintaining the positional relationship of the electrodes 15A arranged in a row. If the connecting sheet 16 were elastic, the positional relationship of the multiple electrodes 15A would be lost due to the electrodes stretching only between some of the electrodes when the device is worn, and the electrodes would come into contact with different positions on the scalp each time the device is worn. (7) The differential amplifier 10, communication circuit 11, and storage battery 12 are built into the connector frame 5 of the headset 1, and the preamplifier 14 and cable 31 are built into the hollow cushion body 13. This prevents the device wearer from touching the electrical configuration, and also increases the durability of the device.

[0028] (Second embodiment) The second embodiment is a variation of the headset 1 of the first embodiment. The second embodiment is a device that measures brain activity in the head when the wearer is in a supine state, that is, lying on his back. In the second embodiment, the frame body 2, cushion body 13, electrodes 15A, electrodes 15B, connecting sheet 16, etc., which are configured the same as the frame body 2 used in the headset 1 of the first embodiment, are used to acquire potential data with an electrical configuration similar to that of the first embodiment. Therefore, differences in appearance from the headset 1 of the first embodiment will be mainly described. Also, the same members as those in the first embodiment are denoted by the same numbers and detailed descriptions will be omitted. A headset 41 according to the second embodiment includes a pair of cases 42 serving as legs that house the distal end of the second portion 2B of the frame body 2. As shown in Fig. 8, the case 42 is a plastic member having a double structure that combines two cylinders, an outer cylinder and an inner cylinder. A main body 43 on the outer cylinder side is composed of a disk-shaped base plate 44 and a hollow cylinder 45 that is erected on the base plate 44 and has a circular cross section. A pair of through holes 46 communicating with the inside and outside are formed at positions 180 degrees opposite each other on the wall of the tubular portion 45. The pair of through holes 46 are respectively formed at three different height positions along the axial direction (up-down direction) of the tubular portion 45. In this embodiment, the pair of through holes 46 are referred to as through holes 46a, 46b, and 46c, from top to bottom. A U-handle-shaped belt pass-through 47 is formed on the outer periphery of the tubular portion 45. A frame body holding cylinder 48, which serves as an inner cylinder, is fitted into the cylinder portion 45 of the main body 43. The frame body holding cylinder 48 is configured so that its outer peripheral shape matches the inner peripheral shape of the cylinder portion 45 (in practice, the inner diameter of the cylinder portion 45 is slightly larger so as to allow sliding movement). The frame body holding cylinder 48 has a hollow portion 49 that opens at the upper end. The hollow portion 49 is a large recess that roughly corresponds to the three-dimensional shape of the portion near the tip of the second portion 2B of the frame body 2. A through hole 50 is formed below the hollow portion 49 of the frame body holding cylinder 48, penetrating toward the center of the frame body holding cylinder 48. The frame body holding cylinder 48 is capable of sliding up and down while being inserted into the cylinder portion 45 of the main body 43, and by inserting the rod 51 from the side while aligning the through hole 50 with any of the through holes 46a to 46c, the frame body holding cylinder 48 can be held at different heights relative to the main body 43. The worker selects three different heights (four if the rod 51 is not inserted) and positions the frame body holding cylinder 48 at the desired height.

[0029] The headset 41 includes a head belt 55. The head belt 55 used in the headset 41 is attached to the belt guide 47 formed in the main body 43 of the case 42. As shown in Figs. 10 and 11, the head belt 55 as a belt member is a strip made of synthetic rubber having elasticity, some stretchability, and flexibility. The head belt 55 has a long rectangular parallelepiped shape as a whole, and a first tape 52 having a large number of small hooks planted therein and a second tape 53 having a large number of small loops planted therein are arranged adjacent to each other near both ends. These tapes 52 and 53 form a hook-and-loop fastener. Two electrodes 15 are attached to the center of the head belt 55 with a gap therebetween. Hereinafter, the electrode 15 attached to the head belt 55 of the second embodiment will be referred to as an electrode 15D. The configuration and attachment structure of the electrode 15D are the same as those of the head belt 25 of the first embodiment, so detailed explanations will be omitted.

[0030] Next, a method of using the headset 41 using such a case 42 will be described. As shown in FIG. 10, a pair of left and right cases 42 are arranged at a predetermined interval on a floor surface on which a wearer lies on his / her back, such as a bed, with the belt loops 47 facing each other. The height of the frame body holding tube 48 of the case 42 is adjusted in advance according to the wearer's physique. Then, as shown in FIG. 11, first, the head belt 55 is passed through the left and right belt loops 47, and the overlapping degree of the tapes 52, 53 (i.e., the hook-and-loop fastener) is adjusted so that a predetermined length is obtained between the pair of cases 42. Next, the head of the wearer lying on his / her back is placed so that the electrode 15D of the head belt 55 is placed at the electrode placement position on the back of the head, and then the tip-side portions of the second parts 2B of the left and right frame bodies 2 are inserted from the tip into the hollow portion 49 that opens upward. Since the tip-side portions of the second parts 2B are slightly flexible, they are inserted while bending slightly outward according to the internal shape of the hollow portion 49, and the frame body 2 is held by the case 42 with a predetermined advancement amount. In the advanced state, the cushion body 13 of the frame body 2 is pushed relatively by the wearer's forehead and bends, and the swinging portion 16B moves inward and abuts against the side of the head, similarly to the first embodiment. According to the headset 41 of the second embodiment, when measuring the brain activity of a wearer lying on his / her back, such as an infant, a small child, or an elderly person, the head can be held above the floor, and the situation around the back of the head can be easily seen. In addition, when a pillow is used, it is difficult to see the state of contact of the electrodes 15D with the back of the head, and there is a high possibility that the electrodes may shift or tilt from the planned electrode placement position. If the head is supported as if by a hammock, as in the case of the headset 41, the head is less likely to move, and the brain activity of the back of the head can be accurately measured.

[0031] (Third embodiment) The third embodiment is a variation of the arrangement of the frame body 2 of the headset 1 of the first embodiment. In the above embodiment, the frame body 2 is arranged on the head T of the wearer from the front to the side, and the head belt 25 is wrapped around the back of the head, as shown in Fig. 6, but the use is not limited to this. For example, as shown in Fig. 12(a), the frame body 67 may be arranged from the top to the side like a headband (hair band) (a head belt may not be required), or as shown in Fig. 12(b), the use may be in the opposite arrangement to Fig. 6, that is, the frame body 2 is arranged on the head T from the back to the side, and the head belt 25 is wrapped around the front of the head.

[0032] The above embodiment has been described merely as a specific embodiment for illustrating the principle and concept of the present invention. In other words, the present invention is not limited to the above embodiment. The present invention can be embodied in the following modified forms, for example. The shapes of the frame body 2, the cushion body 13, the connecting sheet 16, the head belts 25, 55, etc. in the above-mentioned embodiments are merely examples. The shapes of the electrodes 15A to D in the above-described embodiments are merely examples and are not limited thereto. Other shapes are also possible, for example, the shape and number of the protrusions 18 may be other than those described above, or the electrodes may not have the protrusions 18 described above. For example, the electrode 15C may be applied to another electrode, or an electrode such as the other electrode 15A may be applied to the electrode 15C. In addition, the material may be a non-metallic material. The number and positions of the electrodes 15A-D vary depending on the shape of the frame bodies 2, 3, 42, 52, 62 of the brain activity measuring device in each of the above embodiments and the target measurement position of the brain activity measuring device, and are not limited to the above. The above-mentioned shape and material of the connecting sheet 16 serving as the contact body are only examples. The shape of the cushion body 13 in the above embodiment is one example. The number of cushion bodies arranged on one frame body is not limited to the above. The number and positions of the electrodes 15A arranged on each cushion body are not limited to the above, and may be implemented in other ways depending on the situation. For example, a plurality of contact bodies (or connecting members) may be stacked and used at a distance from each other.

[0033] In the above embodiments, the oscillating portion 16B is bent so as to be convex outward, and has a margin for stretching when the cushion body 13 is bent, but it may be formed linearly without such margin. The oscillating portion 16B is displaced when the cushion body 13 is bent, but the displacement may be a rotational movement of the oscillating portion 16B about the fixed end E2, and it is possible to move the electrode 15B inward without changing the overall length of the oscillating portion 16B. Even if it is formed to be bent, it may be bent so as to be convex inward. It may also be curved rather than bent. The oscillating portion 16B is configured as a part of the connecting sheet 16, but as shown in FIG. 13, the oscillating portion 61 may be configured separately from the connecting sheet 16 and disposed between the cushion body 13 and the second part 2B of the frame body 2. Unlike the above embodiment, the length of the connecting sheet 16 is the same as the width of the cushion body 13. One end of the oscillating portion 61 is fixed to the inner wall of the second part 2B of the frame body 2 by a screw 20, and the other end is fixed to the cushion body 13 together with the connecting sheet 16 by a screw 62. The oscillating portion 61 is bent so as to be convex outward. The electrode 15 is attached to any suitable position of the long hole 63 of the oscillating portion 61. As a result, the oscillating portion 61 is bridged between the frame body 2 and the cushion body 13, and the same effect as the first embodiment is achieved. In the above embodiments, the oscillating portion 16B is configured as a single strip-shaped plate, but the strip is not limited to a strip shape. For example, multiple narrow plates may be arranged in parallel to attach the electrodes 15B to the plates. The screw 20 is used as the fixing means for the swinging part 16B on the second part 2B side of the frame body 2, but the means for fixing the swinging part 16B may be a fastening means such as a screw or a pin, but is not limited to this. For example, a cable tie or a hook-and-loop fastener may be used.

[0034] In the first embodiment, the hook-and-loop fastener is used as the fastening means near the tip of the head belt 25 on the outside of the second part 2B of the frame body 2. The hook-and-loop fastener is preferable because it is easy to adjust the length of the head belt 25, but other adjustable fastening means may be used. For example, as shown in FIG. 14, an adjustable fastening means may be used in which a slit 65 is formed near the front of the window 63 of the head belt 25, and a plurality of pins 66 arranged in series on the outside of the second part 2B of the frame body 2 are inserted into the slit 65 to engage the slit 65. Alternatively, an adjustable fastening means such as a belt guide 47 used in the second embodiment and a hook-and-loop fastener using tapes 52, 53 as shown in FIG. 10 may be used. Although the above embodiment describes a brain activity measuring device in an electroencephalogram measuring system, the present invention is not limited to electroencephalograms (EEG) and can also be applied to fNIRS, MEG, fMRI, etc., and is not limited by the measurement principle of brain activity. The present invention may also be applied as a method for fixing a device when stimulating the brain from the outside, such as a magnetic stimulation device (TMS) or a direct current stimulation device (tDCS). The present invention is not limited to the configurations described in the above-mentioned embodiments. The components of each of the above-mentioned embodiments and modifications may be arbitrarily selected and combined. Any component of each of the embodiments and modifications may be arbitrarily combined with any component described in the Summary for Solving the Problems of the Invention or any component that embodies any component described in the Summary for Solving the Problems of the Invention. We intend to obtain rights to these as well through amendments to this application or divisional applications, etc. [Explanation of symbols]

[0035] 1, 41...headset as brain activity measuring device, 2...frame body as frame member, 2A...first part, 2B...second part, 13...cushion body as support body, 15A to 15D...electrodes.

Claims

1. a frame member disposed on the head, the frame member having a first portion disposed in the center and a pair of second portions disposed so as to extend rearward from both left and right ends of the first portion, with the first portion being in the front; a support member having elasticity, the support member being disposed inside the first portion of the frame member and rising inward independently from the first portion side, the support member being configured to be pushed by the head and deformed as the frame member is placed on the head, A brain activity measuring device characterized in that a pair of left and right strips having one or more electrodes attached thereto are suspended by fixing one end to the support side and the other end to the second part side, and when the support side deforms, the strips are arrested by the support side so that the electrodes move inward from the frame member side.

2. 2. The brain activity measuring device according to claim 1, wherein one or more electrodes are attached to the support.

3. 3. The brain activity measuring device according to claim 2, wherein a contact member having a surface to be brought into contact with a head side is formed between the support body and the electrode.

4. 4. The brain activity measuring device according to claim 3, wherein one end of the strip is connected to the contact body.

5. 4. The brain activity measuring device according to claim 3, wherein the strip is a part of the contact body.

6. 4. The brain activity measuring device according to claim 3, wherein the contact body is made of a non-stretchable material.

7. 7. The brain activity measuring device according to claim 1, wherein the strip is made of a non-stretchable material.

8. The brain activity measuring device according to any one of claims 1 to 6, characterized in that the frame member is configured such that when the frame member is placed on the head, the second portion does not come into contact with the head, and one or more electrodes attached to the strip come into contact with the head.

9. 3. The brain activity measuring device according to claim 2, wherein the frame member is arranged so that the first portion crosses the forehead, and brain information of the forehead is obtained by the one or more electrodes of the support.

10. 3. The brain activity measuring device according to claim 2, wherein the frame member is arranged so that the first portion crosses the top of the head, and brain information from the top of the head is obtained by the one or more electrodes of the support.

11. 3. The brain activity measuring device according to claim 2, wherein the frame member is arranged so that the first portion crosses the back of the head, and brain information from the back of the head is obtained by the one or more electrodes of the support.

12. 2. The brain activity measuring device according to claim 1, further comprising a belt member that is stretched between the second portions by fixing both ends to the second portions on the left and right sides of the frame member.

13. The brain activity measuring device according to claim 12, characterized in that the belt member is fixed to the second parts on the left and right sides of the frame member and is positioned to intersect with the tip-side regions of the second parts, and the tip-side regions of the second parts are positioned outside the belt member.

14. 14. The brain activity measuring device according to claim 12, wherein one or a plurality of electrodes are attached to the belt member.

15. The brain activity measuring device according to claim 1, characterized in that the frame member has legs to which the left and right second portions are respectively connected, and when both ends are connected to the left and right legs, the frame member can be raised by the legs so that the first portion is positioned upward, and a belt member is installed between the left and right legs.

16. 16. The brain activity measuring device according to claim 15, wherein one or more electrodes are attached to the belt member stretched between the legs.

17. A brain activity measuring device according to any one of claims 1 to 6, characterized in that a slit is formed in the strip, and the one or more electrodes are attached so as to be movable along the longitudinal direction of the slit.

18. A brain activity measuring system that measures brain activity based on a brain activity signal obtained by the brain activity measuring device according to any one of claims 1 to 6.

19. A brain activity measuring system that measures brain activity based on an electroencephalogram signal obtained by the brain activity measuring device according to any one of claims 1 to 6.

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