Brain wave measuring device and brain wave measuring method

Abstract

Provided is a brain wave measuring device (10) comprising: a support member (20) that is disposed along the head (99) of a subject; an electrode unit (30) that is attached to the support member (20) and contacts the scalp of the subject to acquire a brain wave signal; and a assisting member (attachment part (70)) that assists the placement of the support member (20) on the head (99). The support member (20) is configured from a ribbon-shaped or linear member.

Description

Electroencephalogram measuring device and electroencephalogram measuring method

[0001] The present invention relates to an electroencephalogram measuring device and an electroencephalogram measuring method.

[0002] Various developments have been made with regard to electroencephalogram (EEG) measuring devices for measuring electroencephalograms. For example, a known example of this type of technology is a biosignal measuring device that includes a support made of a shape-memory material, which is a headband worn on the user's head, and a vital sensor attached to the support for acquiring the user's biosignals (see, for example, Patent Document 1). According to the technology disclosed in Patent Document 1, when measuring biosignals, the support can be easily restored to a shape that matches the user's body shape, which has been previously shape-memorized.

[0003] Patent No. 5900167

[0004] When measuring EEG, it is important to ensure that the electrodes fit the shape of the head in order to make contact with the scalp. However, since head shapes vary widely, there has been a need for technology that can accommodate this.

[0005] The present invention has been made in view of the above circumstances, and aims to provide a technique for appropriately bringing an electroencephalogram measuring device, particularly electrodes, into contact with the scalp during electroencephalogram measurement.

[0006] The present invention provides the following technologies: 1. An electroencephalogram (EEG) measuring device having a support member to be placed along the head of a subject, electrode units attached to the support member and in contact with the scalp of the subject to acquire EEG signals, and a support member to assist in placing the support member on the head, wherein the support member is composed of a ribbon-shaped or linear member. 2. The electroencephalogram (EEG) measuring device described in 1., wherein the support member is composed of a non-stretchable member that has flexibility to deform so as to follow the shape of the head. 3. The electroencephalogram (EEG) measuring device described in 1. or 2., wherein the support member is composed of a ribbon-shaped member and has a film member stretched between adjacent electrode units. 4. The electroencephalogram (EEG) measuring device described in 3., wherein the film member is made of a material having a Poisson's ratio of 0.15 to 0.4. 5. The electroencephalogram (EEG) measuring device described in 3. or 4., wherein the product of the elastic modulus and thickness of the film member is 0.4 to 9.1 GPa·mm. 6. The electroencephalogram measuring device according to 1. or 2., wherein, when the support member is constituted by a linear member, the linear member is placed between the electrode units. 7. The electroencephalogram measuring device according to 6., wherein the linear member is provided as at least two spaced-apart members extending from each other, and the electrode unit is provided between the two members. 8. The electroencephalogram measuring device according to any one of 1. to 7., wherein the electrode unit has a base, a plurality of protrusions provided on the base, and electrode units provided on the protrusions and contacting the head. 9. The electroencephalogram measuring device according to 8., wherein the protrusions are elastic members. 10. The electroencephalogram measuring device according to any one of 1. to 9., wherein the assistance member is provided at an end of the support member and is attached to the ear or chin to assist in aligning the support member to the shape of the head. 11. An electroencephalogram measuring method in which the electroencephalogram measuring device according to any one of 1. to 10. is worn on the head of a subject to measure electroencephalograms.

[0007] According to the present invention, it is possible to provide a technique for appropriately bringing an electroencephalogram measuring device, particularly electrodes, into contact with the scalp in electroencephalogram measurement.

[0008] 1 is a schematic diagram showing a state in which an EEG measuring device is attached to a head according to a first embodiment. FIG. 2 is a schematic diagram showing a support member and an attachment unit according to the first embodiment. FIG. 3 is a diagram explaining a model of a force acting on the head when an EEG measuring device is attached (electrode pressing force F on the head) according to the first embodiment. FIG. 4 is a diagram explaining the capstan principle (equation) used for the modeling according to the first embodiment. FIG. 5 is a cross-sectional view of an electrode unit attached to a support member according to the first embodiment. FIG. 6 is a schematic diagram showing a state in which an EEG measuring device is attached to a head according to a second embodiment. FIG. 7 is a schematic diagram showing a support member and an attachment unit according to the second embodiment. FIG. 8 is a cross-sectional view of an electrode unit attached to a support member according to the second embodiment. FIG. 9 is a schematic diagram showing an adjustment unit according to the second embodiment. FIG. 10 is a plan view of an EEG measuring device according to a third embodiment. FIG. 11 is a front view of an EEG measuring device according to the third embodiment. FIG. 12 is a plan view focusing on the attachment mode of the support member for two electrode units at electrode positions Cz and C3 according to the third embodiment. FIG. 13 is a cross-sectional view of an electrode unit attached to a support member according to the third embodiment. 10 is a graph showing theoretical values ​​(calculated values) and actual measured values ​​of electrode pressing force F according to an example.

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, an electroencephalogram (EEG) measuring device having an electrode unit and worn on the head of a subject to acquire electroencephalograms, and an electroencephalogram measuring method using the electroencephalogram measuring device will be described.

[0010] <First embodiment> <Schematic structure of electroencephalogram measuring device 10> Fig. 1 is a schematic diagram showing a state in which an electroencephalogram measuring device 10 is attached to a person's head 99, as viewed from the front. Fig. 2 is a diagram showing a support member 20 and an attachment portion 70 that support an electrode unit 30. In this embodiment, an electroencephalogram measuring device 10 that measures electroencephalograms at electrode positions Cz, C3, C4, T3, and T4 (International 10-20 system) is shown as an example.

[0011] The EEG measuring device 10 is attached to a person's head 99, detects EEGs as potential fluctuations from the living body, and outputs the detected EEGs to an EEG display device (not shown). The EEG display device acquires the EEGs detected by the EEG measuring device 10, displays them on a monitor, stores the data, and performs well-known EEG analysis processing (measurement processing).

[0012] The electroencephalogram (EEG) measuring device 10 has a plurality of electrode units 30 that come into contact with measurement sites (i.e., the head 99) of the subject to acquire electroencephalograms, which are biosignals, a long sheet-like (film-based) support member 20 to which the electrode units 30 are attached and supported, and an attachment section 70 that fixes the support member 20 to the head 99. In this embodiment, the attachment section 70 is attached to the ear of the subject to fix the EEG measuring device 10 to the head 99.

[0013] The support member 20 is configured to be flexible to a certain degree at least in the thickness direction. Furthermore, no member (such as a hard member like a helmet) is provided to surround or pre-shape the support member 20. When not attached to the head 99, the support member 20 and other components can be arranged flat without any external force being applied, and when attached to the head 99, the shape changes mainly due to gravity to conform to the shape of the head 99. Because both ends of the electrode unit 30 may float above the head 99 due to factors such as hair, the attachment portions 70 are used to support the electrode unit 30 in conforming to the shape of the head 99.

[0014] The support member 20 is provided with a concave snap button 25 for fixing the electrode unit 30, and is designed to fit over a convex snap button 35 of the electrode unit 30. The position in the left-right direction where the concave snap button 25 is provided on the support member 20 is exactly at a bent portion 27 where the support member 20 is bent. If the support member 20 is sufficiently thin, the bent portion 27 is not necessary, but the presence of the bent portion 27 allows the support member 20 between the electrode units 30 to be linear.

[0015] The attachment portion 70 has an ear attachment portion 40 and an adjustment portion 50, which are connected by an inextensible member (here, a string 45).

[0016] When the electroencephalogram measuring device 10 is attached to the head 99, the positions of the electrode units 30 are roughly at the vertices of a polygon, and the electrode units 30 are spanned by the support member 20. In other words, the support member 20 is bent exactly at the portion (bending portion 27) where the electrode units 30 are attached.

[0017] <Electrode Pressing Force F on Head> Features of this embodiment will now be described with reference to Fig. 3 and Fig. 4. Fig. 3 is a diagram illustrating a model of the force (electrode pressing force F on the head) acting on the head 99 when the EEG measurement device 10 is worn. Fig. 4 is a diagram illustrating the capstan principle (equation) used for the modeling.

[0018] 3, when the electroencephalogram measuring device 10 is attached to the head 99, a polygon is formed with the electrode units 30 as vertices and the electrode units 30 connected by the support members 20. If it is assumed that the electrode units 30 are pressed against the head 99 by the tension of the support members 20, the force pressing the electrode units 30 against the head 99 (electrode pressing force F) can be expressed by the following equation 1: F=2·T １ cos(θ) Equation 1 In other words, a difference in θ caused by individual differences in head irregularities appears as a difference in the electrode pressing force F.

[0019] Furthermore, the minimum curvature of the inscribed circle is determined from the height and spacing of the electrode units 30. The maximum curvature is also determined from the electrode pressing force F required for the electrode units 30 and the capstan principle. Note that the electrode pressing force F on the head 99 follows the capstan equation, and is therefore greater at the temporal region than at the parietal region.

[0020] Here, it is assumed that the support member 20 (film substrate) is approximately wrapped around the head 99. Because there is friction between the head 99 and the support member 20, the tension of each electrode unit 30 is considered to follow the capstan equation shown in the following equation 2. T １ =T ２ ・e^(μ・φ) ...Formula 2 μ: Friction coefficient φ: Center angle

[0021] From the above formulas 1 and 2, it is possible to understand the relational expression between the tension T1 applied to the end of the support member 20 (film substrate) and the load (electrode pressing force F) that the electrode unit 30 applies to the head 99. The load values ​​calculated from the above theoretical calculations and the actually measured load values ​​will be shown in the examples described later (see FIG. 6).

[0022] <Electrode unit 30> The electrode unit 30 is detachably provided only at the sites required for EEG measurement. The electrode unit 30 is attached at positions corresponding to, for example, T3, C3, Cz, C4, and T4 in the International 10-20 electrode placement method, and is arranged symmetrically in front view as shown in Figure 1.

[0023] 5 shows a cross-sectional view of the electrode unit 30 attached to the concave snap button 25 of the support member 20. The electrode unit 30 is configured as a button electrode and has a convex snap button 35 provided as a connection terminal, which is detachably attached to the concave snap button 25 provided at a predetermined position on the support member 20. In other words, the concave snap button 25 functions as a mounting portion for attaching the electrode unit 30 by a fitting structure.

[0024] The electrode unit 30 may be made entirely of conductive metal, or may have a rubber-like elastic material as a base with a conductive material provided on the surface. The following describes an example of a configuration based on a rubber-like elastic material.

[0025] The detailed structure and materials of the electrode unit 30 are described below. The electrode unit 30 of this embodiment is an electrode (dry electrode) that does not use so-called EEG electrode paste to ensure conductivity. However, a method of forming a gel on the tip of the dry electrode (the tip of the protrusion 32) and immersing it in a wetting liquid or the like to ensure moisture may also be used. Alternatively, instead of using paste or grease, the tip of the dry electrode may be wetted with a conductive auxiliary liquid, such as a low-viscosity liquid like lotion mixed with a small amount of electrolyte such as salt. In other words, the dry electrode of this embodiment is not limited to being completely dry, but rather does not use auxiliary agents that leave significant stains, such as paste.

[0026] The electrode unit 30 has a cylindrical base 31, a protrusion 32 integrally provided on one end of the base 31 (here, the base bottom surface 36), a conductive contact portion 33, a signal line portion 34, and a convex snap button 35 provided on the other end of the base 31 (here, the base top surface 37). Note that, hereinafter, the base 31 and the protrusion 32 will be referred to as an electrode main body 39 for convenience.

[0027] The electrode body 39 is integrally formed from a rubber-like elastic member. Specific materials for the elastic member will be described later. The electrode body 39 (i.e., the base 31 and the protrusions 32) are not limited to being integrally formed, but may be formed as separate parts that are attached together with adhesive or a fitting structure.

[0028] <Shapes of base 31 and protrusions 32> The base 31 is generally cylindrical. A circular base undersurface 36 at one end (the lower side in the figure) of the base 31 is provided with a plurality of generally conical protrusions 32 that protrude downward in the figure. Note that the base 31 may be cylindrical, and the cross section may be a circle or other shape such as a polygon. Furthermore, the shape of the protrusions 32 is not limited to a conical shape, and various shapes such as a pyramid such as a triangular pyramid or a cylindrical shape may be used.

[0029] A conductive contact portion 33 is provided on at least the tip side surface of the protrusion 32. The conductive contact portion 33 may be provided on the entire surface of the protrusion 32. The conductive contact portion 33 is formed in a thin film shape, and the state in which the conductive contact portion 33 is provided on the protrusion 32 can be considered to have substantially the same shape as the shape of the protrusion 32 alone.

[0030] The outer diameter of the base 31 is, for example, 10 mm to 50 mm. The height (thickness) of the base 31 is, for example, 0.1 mm to 30 mm. The height of the protrusion 32 is, for example, 1 mm to 20 mm. The width of the protrusion 32 (outer diameter of the base portion) is, for example, 1 mm to 10 mm.

[0031] <Material of the electrode body 39 (base 31 and protrusions 32)> The material of the electrode body 39 will be described. As described above, the electrode body 39 can be made of a rubber-like elastic material. Specific examples of the rubber-like elastic material include rubber and thermoplastic elastomers (also simply referred to as "elastomers (TPE)"). Examples of rubber include silicone rubber. Examples of thermoplastic elastomers include styrene-based TPE (TPS), olefin-based TPE (TPO), vinyl chloride-based TPE (TPVC), urethane-based TPE (TPU), ester-based TPE (TPEE), and amide-based TPE (TPAE).

[0032] When the material of the electrode body 39 is silicone rubber, the rubber hardness A is, for example, 15 or more and 55 or less, when the Type A durometer hardness on the surface of the electrode body 39 measured at 37°C in accordance with JIS K 6253 (1997) is defined as rubber hardness A.

[0033] Here, the silicone rubber-based curable composition will be described. The silicone rubber can be composed of a cured product of the silicone rubber-based curable composition. The curing process of the silicone rubber-based curable resin composition is carried out, for example, by heating at 100 to 250°C for 1 to 30 minutes (primary curing) and then post-baking at 100 to 200°C for 1 to 4 hours (secondary curing).

[0034] The insulating silicone rubber is a silicone rubber that does not contain a conductive filler, and the conductive silicone rubber is a silicone rubber that contains a conductive filler.

[0035] The silicone rubber-based curable composition according to this embodiment can contain a vinyl group-containing organopolysiloxane (A). The vinyl group-containing organopolysiloxane (A) is a polymer that serves as the main component of the silicone rubber-based curable composition according to this embodiment.

[0036] The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may contain the same type of vinyl group-containing linear organopolysiloxane. The same type of vinyl group-containing linear organopolysiloxanes may be different in the amount of vinyl groups in the molecule, the molecular weight distribution, or the amount of vinyl groups added, as long as they contain the same vinyl groups as functional groups and have a linear shape. The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may further contain different vinyl group-containing organopolysiloxanes.

[0037] The vinyl group-containing organopolysiloxane (A) can include a vinyl group-containing linear organopolysiloxane (A1) having a linear structure.

[0038] The vinyl group-containing linear organopolysiloxane (A1) has a linear structure and contains vinyl groups, and these vinyl groups become crosslinking points during curing.

[0039] The vinyl group content of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited, but preferably contains two or more vinyl groups in the molecule and is 15 mol% or less, and more preferably 0.01 to 12 mol%. This optimizes the amount of vinyl groups in the vinyl group-containing linear organopolysiloxane (A1), ensuring the formation of networks with the components described below. In this embodiment, the symbol "to" means that both ends of the symbol are included.

[0040] In this specification, the vinyl group content refers to the mol % of vinyl group-containing siloxane units when all units constituting the vinyl group-containing linear organopolysiloxane (A1) are taken as 100 mol %, where it is considered that there is one vinyl group per vinyl group-containing siloxane unit.

[0041] The degree of polymerization of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited, but is preferably within a range of, for example, about 1,000 to 10,000, and more preferably about 2,000 to 5,000. The degree of polymerization can be determined, for example, as the polystyrene-equivalent number average degree of polymerization (or number average molecular weight) measured by GPC (gel permeation chromatography) using chloroform as a developing solvent.

[0042] Furthermore, the specific gravity of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited, but is preferably in the range of about 0.9 to 1.1.

[0043] By using a vinyl group-containing linear organopolysiloxane (A1) having a degree of polymerization and specific gravity within the above ranges, the heat resistance, flame retardancy, chemical stability, and other properties of the resulting silicone rubber can be improved.

[0044] As the vinyl group-containing linear organopolysiloxane (A1), those having a structure represented by the following formula (1) are particularly preferred.

[0045]

[0046] In formula (1), R １ is a hydrocarbon group that is a substituted or unsubstituted alkyl group, alkenyl group, aryl group, or a combination thereof having 1 to 10 carbon atoms. Examples of alkyl groups having 1 to 10 carbon atoms include methyl groups, ethyl groups, and propyl groups, with methyl groups being preferred. Examples of alkenyl groups having 1 to 10 carbon atoms include vinyl groups, allyl groups, and butenyl groups, with vinyl groups being preferred. Examples of aryl groups having 1 to 10 carbon atoms include phenyl groups.

[0047] Also, R ２ is a hydrocarbon group that is a substituted or unsubstituted alkyl group, alkenyl group, aryl group, or a combination thereof having 1 to 10 carbon atoms. Examples of alkyl groups having 1 to 10 carbon atoms include methyl groups, ethyl groups, and propyl groups, with methyl groups being preferred. Examples of alkenyl groups having 1 to 10 carbon atoms include vinyl groups, allyl groups, and butenyl groups. Examples of aryl groups having 1 to 10 carbon atoms include phenyl groups.

[0048] Also, R ３ is a substituted or unsubstituted alkyl group or aryl group having 1 to 8 carbon atoms, or a hydrocarbon group combining these. Examples of alkyl groups having 1 to 8 carbon atoms include methyl groups, ethyl groups, and propyl groups, with methyl groups being preferred. Examples of aryl groups having 1 to 8 carbon atoms include phenyl groups.

[0049] Furthermore, R in formula (1) １ and R ２ Examples of the substituent of R include a methyl group and a vinyl group. ３ Examples of the substituent include a methyl group.

[0050] In addition, in formula (1), a plurality of R １ are independent of each other and may be different from each other or may be the same. ２ , and R ３ The same is true for .

[0051] Furthermore, m and n are the numbers of repeating units constituting the vinyl group-containing linear organopolysiloxane (A1) represented by formula (1), where m is an integer of 0 to 2000 and n is an integer of 1000 to 10000. m is preferably 0 to 1000, and n is preferably 2000 to 5000.

[0052] Specific examples of the vinyl group-containing linear organopolysiloxane (A1) represented by formula (1) include those represented by the following formula (1-1):

[0053]

[0054] In formula (1-1), R １ and R ２ are each independently a methyl group or a vinyl group, and at least one of them is a vinyl group.

[0055] Furthermore, the vinyl group-containing linear organopolysiloxane (A1) preferably contains a first vinyl group-containing linear organopolysiloxane (A1-1) having two or more vinyl groups in the molecule and a vinyl group content of 0.4 mol% or less, and a second vinyl group-containing linear organopolysiloxane (A1-2) having a vinyl group content of 0.5 to 15 mol%. Combining a first vinyl group-containing linear organopolysiloxane (A1-1) with a vinyl group content typical of crude rubber, which is the raw material for silicone rubber, with a second vinyl group-containing linear organopolysiloxane (A1-2) with a high vinyl group content allows for uneven distribution of vinyl groups and more effectively creates a variation in crosslink density within the crosslinked network of the silicone rubber. As a result, the tear strength of the silicone rubber can be more effectively increased.

[0056] Specifically, the vinyl group-containing linear organopolysiloxane (A1) may be, for example, a vinyl group-containing linear organopolysiloxane represented by the above formula (1-1), １ is a vinyl group and / or R ２a first vinyl group-containing linear organopolysiloxane (A1-1) having two or more units in the molecule in which R is a vinyl group and containing 0.4 mol% or less of the unit; １ is a vinyl group and / or R ２ It is preferable to use a second vinyl group-containing linear organopolysiloxane (A1-2) containing 0.5 to 15 mol % of units in which each of the units is a vinyl group.

[0057] The first vinyl group-containing linear organopolysiloxane (A1-1) preferably has a vinyl group content of 0.01 to 0.2 mol %, and the second vinyl group-containing linear organopolysiloxane (A1-2) preferably has a vinyl group content of 0.8 to 12 mol %.

[0058] Furthermore, when the first vinyl group-containing linear organopolysiloxane (A1-1) and the second vinyl group-containing linear organopolysiloxane (A1-2) are combined and blended, the ratio of (A1-1) to (A1-2) is not particularly limited, but for example, the weight ratio of (A1-1):(A1-2) is preferably 50:50 to 95:5, and more preferably 80:20 to 90:10.

[0059] The first and second vinyl group-containing linear organopolysiloxanes (A1-1) and (A1-2) may each be used alone or in combination of two or more.

[0060] The vinyl group-containing organopolysiloxane (A) may also contain a vinyl group-containing branched organopolysiloxane (A2) having a branched structure.

[0061] <<Organohydrogenpolysiloxane (B)>> The silicone rubber-based curable composition of this embodiment may contain a crosslinking agent. The crosslinking agent may contain an organohydrogenpolysiloxane (B). The organohydrogenpolysiloxane (B) is classified into a linear organohydrogenpolysiloxane (B1) having a linear structure and a branched organohydrogenpolysiloxane (B2) having a branched structure, and may contain either one or both of these.

[0062] The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may contain the same type of crosslinking agent. The same type of crosslinking agent only needs to have a common structure, such as a linear or branched structure, and may have different molecular weight distributions or different functional groups in the molecule, or the amounts added may differ. The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may further contain different crosslinking agents.

[0063] The linear organohydrogenpolysiloxane (B1) has a linear structure and a structure in which hydrogen is directly bonded to Si (≡Si—H), and is a polymer that undergoes a hydrosilylation reaction with the vinyl groups of the vinyl group-containing organopolysiloxane (A) and with vinyl groups of components blended into the silicone rubber-based curable composition, thereby crosslinking these components.

[0064] The molecular weight of the linear organohydrogenpolysiloxane (B1) is not particularly limited, but for example, the weight average molecular weight is preferably 20,000 or less, and more preferably 1,000 or more and 10,000 or less.

[0065] The weight average molecular weight of the linear organohydrogenpolysiloxane (B1) can be measured, for example, by gel permeation chromatography (GPC) using chloroform as a developing solvent, in terms of polystyrene.

[0066] Furthermore, it is generally preferred that the linear organohydrogenpolysiloxane (B1) does not contain a vinyl group, which can reliably prevent the crosslinking reaction from proceeding within the molecule of the linear organohydrogenpolysiloxane (B1).

[0067] As the linear organohydrogenpolysiloxane (B1) described above, for example, one having a structure represented by the following formula (2) is preferably used.

[0068]

[0069] In formula (2), R ４is a substituted or unsubstituted alkyl group, alkenyl group, aryl group, a hydrocarbon group combining these, or a hydride group having 1 to 10 carbon atoms. Examples of alkyl groups having 1 to 10 carbon atoms include methyl groups, ethyl groups, and propyl groups, with methyl groups being preferred. Examples of alkenyl groups having 1 to 10 carbon atoms include vinyl groups, allyl groups, and butenyl groups. Examples of aryl groups having 1 to 10 carbon atoms include phenyl groups.

[0070] Also, R ５ is a substituted or unsubstituted alkyl group, alkenyl group, aryl group, a hydrocarbon group combining these, or a hydride group having 1 to 10 carbon atoms. Examples of alkyl groups having 1 to 10 carbon atoms include methyl groups, ethyl groups, and propyl groups, with methyl groups being preferred. Examples of alkenyl groups having 1 to 10 carbon atoms include vinyl groups, allyl groups, and butenyl groups. Examples of aryl groups having 1 to 10 carbon atoms include phenyl groups.

[0071] In addition, in formula (2), a plurality of R ４ are independent of each other and may be different from each other or may be the same. ５ The same applies to multiple R ４ and R ５ At least two of these are hydride groups.

[0072] Also, R ６ is a substituted or unsubstituted alkyl group or aryl group having 1 to 8 carbon atoms, or a hydrocarbon group combining these. Examples of alkyl groups having 1 to 8 carbon atoms include methyl groups, ethyl groups, and propyl groups, and among these, methyl groups are preferred. Examples of aryl groups having 1 to 8 carbon atoms include phenyl groups. ６ are independent of each other and may be different from each other or may be the same.

[0073] In addition, R in formula (2) ４ , R ５ , R ６Examples of the substituent include a methyl group and a vinyl group, and a methyl group is preferred from the viewpoint of preventing intramolecular crosslinking reactions.

[0074] Furthermore, m and n are the numbers of repeating units constituting the linear organohydrogenpolysiloxane (B1) represented by formula (2), where m is an integer of 2 to 150 and n is an integer of 2 to 150. Preferably, m is an integer of 2 to 100 and n is an integer of 2 to 100.

[0075] The linear organohydrogenpolysiloxane (B1) may be used alone or in combination of two or more.

[0076] Because the branched organohydrogenpolysiloxane (B2) has a branched structure, it forms regions with high crosslink density and is a component that significantly contributes to the formation of a sparsely crosslinked structure in the silicone rubber system. Similarly to the linear organohydrogenpolysiloxane (B1), it has a structure in which hydrogen is directly bonded to Si (≡Si—H), and undergoes a hydrosilylation reaction with the vinyl groups of the vinyl group-containing organopolysiloxane (A) and with the vinyl groups of other components incorporated into the silicone rubber-based curable composition, forming a polymer that crosslinks these components.

[0077] The specific gravity of the branched organohydrogenpolysiloxane (B2) is in the range of 0.9 to 0.95.

[0078] Furthermore, it is generally preferred that the branched organohydrogenpolysiloxane (B2) does not contain a vinyl group, which can reliably prevent the crosslinking reaction from proceeding within the molecule of the branched organohydrogenpolysiloxane (B2).

[0079] The branched organohydrogenpolysiloxane (B2) is preferably one represented by the following average composition formula (c):

[0080] Average compositional formula (c) (H ａ (R ７ ) ３－ａ SiO １／２ ) ｍ (SiO ４／２ ) ｎ(In formula (c), R ７ is a monovalent organic group, a is an integer ranging from 1 to 3, and m is H ａ (R ７ ) ３－ａ SiO １／２ The number of units, n, is SiO ４／２ (number of units)

[0081] In formula (c), R ７ is a monovalent organic group, preferably a substituted or unsubstituted alkyl group or aryl group having 1 to 10 carbon atoms, or a hydrocarbon group consisting of a combination thereof. Examples of alkyl groups having 1 to 10 carbon atoms include methyl, ethyl, and propyl groups, with methyl being preferred. Examples of aryl groups having 1 to 10 carbon atoms include phenyl groups.

[0082] In formula (c), a is the number of hydride groups (hydrogen atoms directly bonded to Si), and is an integer ranging from 1 to 3, preferably 1.

[0083] In addition, in formula (c), m is H ａ (R ７ ) ３－ａ SiO １／２ The number of units, n, is SiO ４／２ The number of units.

[0084] The branched organohydrogenpolysiloxane (B2) has a branched structure. The linear organohydrogenpolysiloxane (B1) and the branched organohydrogenpolysiloxane (B2) differ in their structures, that is, whether they are linear or branched, and the number of alkyl groups R bonded to Si (R / Si), where the number of Si is 1, is in the range of 1.8 to 2.1 for the linear organohydrogenpolysiloxane (B1) and 0.8 to 1.7 for the branched organohydrogenpolysiloxane (B2).

[0085] Because the branched organohydrogenpolysiloxane (B2) has a branched structure, it leaves a residue amount of 5% or more when heated, for example, in a nitrogen atmosphere to 1,000° C. at a heating rate of 10° C. / min. In contrast, because the linear organohydrogenpolysiloxane (B1) is linear, it leaves a residue amount of almost zero after heating under the above conditions.

[0086] Specific examples of the branched organohydrogenpolysiloxane (B2) include those having a structure represented by the following formula (3).

[0087]

[0088] In formula (3), R ７ is a substituted or unsubstituted alkyl group or aryl group having 1 to 8 carbon atoms, or a hydrocarbon group combining these, or a hydrogen atom. Examples of alkyl groups having 1 to 8 carbon atoms include methyl groups, ethyl groups, and propyl groups, with methyl groups being preferred. Examples of aryl groups having 1 to 8 carbon atoms include phenyl groups. R ７ Examples of the substituent include a methyl group.

[0089] In addition, in formula (3), a plurality of R ７ are independent of each other and may be different from each other or may be the same.

[0090] In addition, in formula (3), "-O-Si≡" indicates that Si has a branched structure that spreads three-dimensionally.

[0091] The branched organohydrogenpolysiloxane (B2) may be used alone or in combination of two or more.

[0092] Furthermore, the amount of hydrogen atoms (hydride groups) directly bonded to Si in the linear organohydrogenpolysiloxane (B1) and the branched organohydrogenpolysiloxane (B2) is not particularly limited. However, in the silicone rubber-based curable composition, the total amount of hydride groups in the linear organohydrogenpolysiloxane (B1) and the branched organohydrogenpolysiloxane (B2) is preferably 0.5 to 5 moles, more preferably 1 to 3.5 moles, per mole of vinyl groups in the vinyl group-containing linear organopolysiloxane (A1). This ensures the reliable formation of a crosslinked network between the linear organohydrogenpolysiloxane (B1) and the branched organohydrogenpolysiloxane (B2) and the vinyl group-containing linear organopolysiloxane (A1).

[0093] <<Silica Particles (C)>> The silicone rubber-based curable composition according to this embodiment contains a non-conductive filler. The non-conductive filler may contain silica particles (C) as needed. This can improve the hardness and mechanical strength of the elastomer.

[0094] The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may contain the same type of non-conductive filler. Non-conductive fillers of the same type may have at least common constituent materials, but may differ in particle size, specific surface area, surface treatment agent, or the amount of surface treatment agent added. The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may further contain different silane coupling agents.

[0095] The silica particles (C) are not particularly limited, but examples thereof include fumed silica, calcined silica, precipitated silica, etc. These may be used alone or in combination of two or more.

[0096] The silica particles (C) have a specific surface area of, for example, 50 to 400 m2 as measured by the BET method. ２ / g, and 100 to 400m ２The average primary particle size of the silica particles (C) is preferably, for example, 1 to 100 nm, and more preferably about 5 to 20 nm.

[0097] By using silica particles (C) having a specific surface area and average particle size within the above ranges, it is possible to improve the hardness and mechanical strength, particularly the tensile strength, of the silicone rubber formed.

[0098] <<Silane Coupling Agent (D)>> The silicone rubber-based curable composition of this embodiment can contain a silane coupling agent (D). The silane coupling agent (D) can have a hydrolyzable group. The hydrolyzable group is hydrolyzed by water to form a hydroxyl group, and this hydroxyl group undergoes a dehydration condensation reaction with the hydroxyl groups on the surface of the silica particles (C), thereby modifying the surface of the silica particles (C).

[0099] The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may contain the same type of silane coupling agent. Silane coupling agents of the same type may have at least a common functional group, but may differ in other functional groups in the molecule or in the amount added. The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may further contain different silane coupling agents.

[0100] Furthermore, this silane coupling agent (D) can contain a silane coupling agent having a hydrophobic group. This provides the hydrophobic group to the surface of the silica particles (C), thereby reducing the cohesive force of the silica particles (C) in the silicone rubber-based curable composition, and ultimately in the silicone rubber (reducing aggregation due to hydrogen bonding through silanol groups). This is presumably improving the dispersibility of the silica particles (C) in the silicone rubber-based curable composition. This increases the interface between the silica particles (C) and the rubber matrix, enhancing the reinforcing effect of the silica particles (C). Furthermore, it is presumed that the slipperiness of the silica particles (C) within the matrix improves during deformation of the rubber matrix. The improved dispersibility and slipperiness of the silica particles (C) improve the mechanical strength (e.g., tensile strength, tear strength, etc.) of the silicone rubber due to the silica particles (C).

[0101] Furthermore, the silane coupling agent (D) can contain a silane coupling agent having a vinyl group. This allows the vinyl group to be introduced onto the surface of the silica particles (C). Therefore, when the silicone rubber-based curable composition is cured, that is, when the vinyl group of the vinyl group-containing organopolysiloxane (A) and the hydride group of the organohydrogenpolysiloxane (B) undergo a hydrosilylation reaction to form a network (crosslinked structure), the vinyl group of the silica particles (C) also participates in the hydrosilylation reaction with the hydride group of the organohydrogenpolysiloxane (B), and the silica particles (C) are also incorporated into the network. This allows the formed silicone rubber to have a low hardness and a high modulus.

[0102] As the silane coupling agent (D), a silane coupling agent having a hydrophobic group and a silane coupling agent having a vinyl group can be used in combination.

[0103] Examples of the silane coupling agent (D) include those represented by the following formula (4).

[0104] Y ｎ -Si-(X) ４－ｎ...(4) In the above formula (4), n represents an integer of 1 to 3. Y represents a functional group having a hydrophobic group, a hydrophilic group, or a vinyl group, and when n is 1, it is a hydrophobic group, and when n is 2 or 3, at least one of the groups is a hydrophobic group. X represents a hydrolyzable group.

[0105] The hydrophobic group is an alkyl group having 1 to 6 carbon atoms, an aryl group, or a hydrocarbon group formed by combining these groups, such as a methyl group, an ethyl group, a propyl group, or a phenyl group, with a methyl group being particularly preferred.

[0106] Examples of the hydrophilic group include a hydroxyl group, a sulfonic acid group, a carboxyl group, and a carbonyl group, and among these, a hydroxyl group is particularly preferred. Although a hydrophilic group may be contained as a functional group, it is preferable that the hydrophilic group is not contained from the viewpoint of imparting hydrophobicity to the silane coupling agent (D).

[0107] Further, examples of the hydrolyzable group include an alkoxy group such as a methoxy group or an ethoxy group, a chloro group, or a silazane group. Among these, a silazane group is preferred because of its high reactivity with the silica particles (C). Note that, in the case of a compound having a silazane group as a hydrolyzable group, the (Y ｎ The resulting structure has two —Si— structures.

[0108] Specific examples of the silane coupling agent (D) represented by the above formula (4) are as follows. Examples of the silane coupling agent (D) having a hydrophobic group as the functional group include alkoxysilanes such as methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, and decyltrimethoxysilane; chlorosilanes such as methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, and phenyltrichlorosilane; and hexamethyldisilazane. Among these, silane coupling agents having a trimethylsilyl group containing one or more selected from the group consisting of hexamethyldisilazane, trimethylchlorosilane, trimethylmethoxysilane, and trimethylethoxysilane are preferred.

[0109] As the one having vinyl group as the functional group, for example, can be mentioned alkoxysilane such as methacryloxypropyltriethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane; chlorosilane such as vinyltrichlorosilane, vinylmethyldichlorosilane; divinyltetramethyldisilazane.Among these, preferred is the silane coupling agent having vinyl group-containing organosilyl group, comprising one or more selected from the group consisting of methacryloxypropyltriethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, divinyltetramethyldisilazane, vinyltriethoxysilane, vinyltrimethoxysilane and vinylmethyldimethoxysilane.

[0110] Furthermore, when the silane coupling agent (D) contains two types of silane coupling agents, one having a trimethylsilyl group and the other having a vinyl group-containing organosilyl group, it is preferable that the silane coupling agent containing the hydrophobic group is hexamethyldisilazane, and the silane coupling agent containing the vinyl group is divinyltetramethyldisilazane.

[0111] When a silane coupling agent (D1) having a trimethylsilyl group and a silane coupling agent (D2) having a vinyl group-containing organosilyl group are used in combination, the ratio of (D1) to (D2) is not particularly limited, but for example, the weight ratio of (D1):(D2) is 1:0.001 to 1:0.35, preferably 1:0.01 to 1:0.20, and more preferably 1:0.03 to 1:0.15. By adjusting the weight ratio within this range, the desired physical properties of the silicone rubber can be obtained. Specifically, a balance can be achieved between the dispersibility of silica in the rubber and the crosslinkability of the rubber.

[0112] In this embodiment, the lower limit of the content of the silane coupling agent (D) is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, relative to 100 parts by weight of the total amount of the vinyl group-containing organopolysiloxane (A). The upper limit of the content of the silane coupling agent (D) is preferably 100% by mass or less, more preferably 80% by mass or less, and even more preferably 40% by mass or less, relative to 100 parts by weight of the total amount of the vinyl group-containing organopolysiloxane (A). By setting the content of the silane coupling agent (D) to the above lower limit or more, the adhesion between the columnar portion containing the elastomer and the conductive resin layer can be improved. This can also contribute to improving the mechanical strength of the silicone rubber. Setting the content of the silane coupling agent (D) to the above upper limit or less allows the silicone rubber to have appropriate mechanical properties.

[0113] <<Platinum or Platinum Compound (E)>> The silicone rubber-based curable composition according to this embodiment may contain a catalyst. The catalyst may contain platinum or a platinum compound (E). The platinum or platinum compound (E) is a catalytic component that acts as a catalyst during curing. The amount of platinum or platinum compound (E) added is a catalytic amount.

[0114] The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may contain the same type of catalyst. The same type of catalyst is sufficient as long as they have at least common constituent materials, and the catalyst may contain different compositions, and the amounts added may be different. The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may further contain different catalysts.

[0115] As the platinum or platinum compound (E), known compounds can be used, such as platinum black, platinum supported on silica or carbon black, chloroplatinic acid or an alcohol solution of chloroplatinic acid, a complex salt of chloroplatinic acid and an olefin, and a complex salt of chloroplatinic acid and a vinylsiloxane.

[0116] The platinum or platinum compound (E) may be used alone or in combination of two or more.

[0117] In this embodiment, the content of platinum or platinum compound (E) in the silicone rubber-based curable composition refers to a catalytic amount and can be set as appropriate. Specifically, the amount is an amount such that the platinum group metal is 0.01 to 1000 ppm by weight, preferably 0.1 to 500 ppm, per 100 parts by weight of the total amount of the vinyl group-containing organopolysiloxane (A), silica particles (C), and silane coupling agent (D). By setting the content of platinum or platinum compound (E) to be equal to or greater than the above-mentioned lower limit, the silicone rubber-based curable composition can be cured at an appropriate rate. Furthermore, setting the content of platinum or platinum compound (E) to be equal to or less than the above-mentioned upper limit can contribute to reducing production costs.

[0118] <<Water (F)>> Furthermore, the silicone rubber-based hardening composition according to this embodiment may contain water (F) in addition to the above components (A) to (E).

[0119] Water (F) functions as a dispersion medium for dispersing the components contained in the silicone rubber-based curable composition, and is also a component that contributes to the reaction between the silica particles (C) and the silane coupling agent (D). Therefore, the silica particles (C) and the silane coupling agent (D) can be more reliably bonded to each other in the silicone rubber, and uniform properties can be exhibited overall.

[0120] (Other Components) Furthermore, the silicone rubber-based curable composition of this embodiment may further contain other components in addition to the above components (A) to (F). Examples of these other components include inorganic fillers other than the silica particles (C), such as diatomaceous earth, iron oxide, zinc oxide, titanium oxide, barium oxide, magnesium oxide, cerium oxide, calcium carbonate, magnesium carbonate, zinc carbonate, glass wool, and mica, as well as additives such as reaction inhibitors, dispersants, pigments, dyes, antistatic agents, antioxidants, flame retardants, and thermal conductivity improvers.

[0121] The conductive solution (conductive silicone rubber composition) according to this embodiment contains the above-mentioned conductive filler and solvent in addition to the above-mentioned silicone rubber-based curable composition that does not contain a conductive filler.

[0122] As the solvent, various known solvents can be used, including, for example, high-boiling point solvents, which may be used alone or in combination of two or more.

[0123] Examples of the solvent include aliphatic hydrocarbons such as pentane, hexane, cyclohexane, heptane, methylcyclohexane, ethylcyclohexane, octane, decane, dodecane, and tetradecane; aromatic hydrocarbons such as benzene, toluene, ethylbenzene, xylene, trifluoromethylbenzene, and benzotrifluoride; ethers such as diethyl ether, diisopropyl ether, dibutyl ether, cyclopentyl methyl ether, cyclopentyl ethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, 1,4-dioxane, 1,3-dioxane, and tetrahydrofuran; haloalkanes such as dichloromethane, chloroform, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,1-trichloroethane, and 1,1,2-trichloroethane; carboxylic acid amides such as N,N-dimethylformamide and N,N-dimethylacetamide; and sulfoxides such as dimethyl sulfoxide and diethyl sulfoxide. These may be used alone or in combination of two or more.

[0124] The conductive solution can have a viscosity suitable for various application methods such as spray application and dip application by adjusting the amount of solids in the solution.

[0125] Furthermore, when the conductive solution contains the conductive filler and the silica particles (C), the lower limit of the content of the silica particles (C) contained in the electrode part main body 39 can be, for example, 1% by mass or more, preferably 3% by mass or more, and more preferably 5% by mass or more, relative to 100% by mass of the total amount of the silica particles (C) and the conductive filler. This can improve the mechanical strength of the electrode part main body 39. On the other hand, the upper limit of the content of the silica particles (C) contained in the electrode part main body 39 can be, for example, 20% by mass or less, preferably 15% by mass or less, and more preferably 10% by mass or less, relative to 100% by mass of the total amount of the silica particles (C) and the conductive filler. This can achieve a balance between the conductivity of the electrode part main body 39 and the mechanical strength and flexibility.

[0126] The conductive solution can be heated and dried as needed to obtain conductive silicone rubber. The conductive silicone rubber may be configured to not contain silicone oil. This prevents the silicone oil from bleeding out onto the surface of the electrode body 39, thereby preventing a decrease in conductivity.

[0127] <Material of Conductive Contact Portion 33> The conductive member of the conductive contact portion 33 is, for example, a paste containing a highly conductive metal (so-called conductive paste). The highly conductive metal includes one or more metals selected from the group consisting of copper, silver, gold, nickel, tin, lead, zinc, bismuth, antimony, and alloys thereof. In particular, silver, silver chloride, and copper are suitable from the viewpoints of availability and conductivity.

[0128] When the conductive contact portion 33 is formed from a paste containing a highly conductive metal, the top of the protrusion portion 32 made of a rubber-like elastic body is dipped (dipped and coated) into a paste-like conductive solution containing a highly conductive metal, thereby forming the conductive contact portion 33 on the surface of the protrusion portion 32.

[0129] The conductive contact portion 33 may be formed as a conductive resin layer by applying a conductive solution containing a conductive filler and a solvent to the protrusion portion 32. In this case, by using the same material (silicone rubber) as the solvent for the protrusion portion 32, the adhesion of the conductive contact portion 33 (conductive resin layer) can be improved.

[0130] The conductive solution is heated and dried as needed to obtain a conductive silicone rubber. The conductive silicone rubber may be configured not to contain silicone oil. This prevents the silicone oil from bleeding out onto the surface of the conductive contact 33, thereby preventing a decrease in conductivity.

[0131] This improves the ability to push aside hair when the electroencephalogram measuring device 1 is attached to the head 99. Furthermore, it is possible to ensure a sufficient contact area of ​​the conductive contact portion 33 when the electroencephalogram measuring device 1 is attached.

[0132] <Structure of Signal Wire Portion 34> The electrode unit 30 is provided with a signal wire portion 34 as a signal path connected to the conductive contact portion 33. The signal wire portion 34 may have any wiring structure as long as it provides electrical continuity via the base 31 and the protrusion 32. Here, the signal wire portion 34 is provided so as to extend from the conductive contact portion 33 at the tip of the protrusion 32, pass through the interior of the protrusion 32 and the base 31, and be exposed on the base upper surface 37. The portion of the signal wire portion 34 that protrudes from the base upper surface 37 (here, the end portion 34a) is sandwiched between the convex snap button 35 (more specifically, the disk portion 35a described below) and the base upper surface 37, ensuring electrical continuity with the convex snap button 35.

[0133] The lower tip of the signal line portion 34 may have any of a protruding structure, a structure that is substantially flush with the tip of the protrusion 32 or its vicinity, i.e., a structure that is buried in the region where the conductive contact portion 33 is formed. A protruding structure may be used from the viewpoint of connection stability with the conductive contact portion 33. The protruding portion of the tip of the signal line portion 34 is partially or entirely covered with the conductive contact portion 33. The protruding structure of the tip of the signal line portion 34 may be unfolded, folded, or wrapped around the surface of the tip of the protrusion 32.

[0134] As another wiring structure for the signal line portion 34, it may be a structure in which it is provided on the surfaces of the protrusion portion 32 and the base portion 31, or a wiring structure in which a part of it is provided inside and a part of it is provided on the surface. In other words, it is sufficient if the signal detected by the conductive contact portion 33 is ultimately transmitted to the convex snap button 35.

[0135] <Material of the Signal Wire Portion 34> The signal wire portion 34 may be made of a known material, for example, conductive fiber. The conductive fiber may be one or more types selected from the group consisting of metal fiber, metal-coated fiber, carbon fiber, conductive polymer fiber, conductive polymer-coated fiber, and conductive paste-coated fiber. These may be used alone or in combination of two or more types.

[0136] The metal material of the metal fibers and metal-coated fibers is not limited as long as it is conductive, but examples include copper, silver, gold, nickel, tin, lead, zinc, bismuth, antimony, stainless steel, aluminum, silver / silver chloride, and alloys thereof. These may be used alone or in combination of two or more. Among these, silver can be used from the viewpoint of conductivity. Furthermore, it is preferable that the metal material does not contain metals that put a burden on the environment, such as chromium.

[0137] The fiber materials for the metal-coated fibers, conductive polymer-coated fibers, and conductive paste-coated fibers are not particularly limited, but may be synthetic fibers, semi-synthetic fibers, or natural fibers. Among these, polyester, nylon, polyurethane, silk, cotton, etc. are preferred. These may be used alone or in combination of two or more.

[0138] Examples of the carbon fiber include PAN-based carbon fiber and pitch-based carbon fiber.

[0139] The conductive polymer material for the conductive polymer fibers and conductive polymer-coated fibers may be, for example, a mixture of a conductive polymer such as polythiophene, polypyrrole, polyaniline, polyacetylene, polyphenylene vinylene, polynaphthalene, or a derivative thereof and a binder resin, or an aqueous solution of a conductive polymer such as PEDOT-PSS ((3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid)).

[0140] The resin material contained in the conductive paste of the conductive paste-coated fiber is not particularly limited, but preferably has elasticity, and may contain, for example, one or more selected from the group consisting of silicone rubber, urethane rubber, fluororubber, nitrile rubber, acrylic rubber, styrene rubber, chloroprene rubber, and ethylene propylene rubber. These may be used alone or in combination of two or more.

[0141] The conductive filler contained in the conductive paste of the conductive paste-coated fiber is not particularly limited, and may be any known conductive material, but may include one or more selected from the group consisting of metal particles, metal fibers, metal-coated fibers, carbon black, acetylene black, graphite, carbon fibers, carbon nanotubes, conductive polymers, conductive polymer-coated fibers, and metal nanowires.

[0142] The metal constituting the conductive filler is not particularly limited, but may include, for example, at least one of copper, silver, gold, nickel, tin, lead, zinc, bismuth, antimony, silver / silver chloride, or alloys thereof, or two or more of these. Among these, silver or copper is preferred because of its high conductivity and easy availability.

[0143] The signal line portion 34 may be made of a twisted yarn made by twisting together a plurality of linear conductive fibers, which can prevent the signal line portion 34 from breaking when the device is deformed.

[0144] In this embodiment, the coating of conductive fibers does not simply mean covering the outer surface of the fiber material, but also includes, in the case of a twisted yarn made by twisting together single fibers, impregnating the gaps between the fibers in the twisted yarn with metal, conductive polymer, or conductive paste to coat each of the single fibers that make up the twisted yarn.

[0145] The tensile elongation at break of the signal line portion 34 is, for example, 1% to 50%, and preferably 1.5% to 45%. By setting the elongation at break within this range, excessive deformation of the protrusion 32 can be suppressed while suppressing breakage during deformation.

[0146] <Convex snap button 35 and concave snap button 25> The convex snap button 35 is made of, for example, a metal with good electrical conductivity and has a disk-shaped disk portion 35a and a convex button-shaped button portion 35b extending from the center of the upper surface of the disk portion 35a. Examples of the metal with good electrical conductivity that can be used include stainless steel, copper alloy, aluminum alloy, brass, etc.

[0147] The disk portion 35a is attached to the base upper surface 37 of the base 31 with a conductive adhesive or the like. At this time, as described above, the end portion 34a of the signal line portion 34 is sandwiched between the disk portion 35a and the base upper surface 37, ensuring electrical continuity with the convex snap button 35. The button portion 35b is attached so as to fit into the concave snap button 25 provided on the support member 20. The concave snap button 25, like the convex snap button 35, is made of a metal with good electrical conductivity, and outputs the electroencephalograms acquired by the electrode unit 30 to an electroencephalogram display device or the like via a predetermined wiring structure (not shown).

[0148] <Support Member 20> The support member 20 has a ribbon-shaped member. More specifically, the support member 20 is configured with a long, strip-shaped film substrate. The support member 20 may be configured with a single type of film substrate, or may be a composite member configured with multiple film substrates. In either case, the support member 20 is configured to have sufficient strength for attaching the electrode units 30. That is, the support member 20 has sufficient strength to prevent breakage when recessed snap buttons 25 are provided and the electrode units 30 are attached. Furthermore, the support member 20 has non-stretchable physical properties (non-stretchable) so that the multiple electrode units 30 can be pressed against the head 99 with an appropriate pressure, i.e., so that a constant tension acts. "Non-stretchable" means, for example, that the Poisson's ratio, described below, falls within a predetermined range.

[0149] The vertical width (depth length) of the support member 20 depends on the size of the electrode unit 30 to be attached, but can be, for example, 5 mm to 50 mm. The horizontal width (left-right length) of the support member 20 depends on the size of the head 99 and the electrode position, but can be, for example, 200 mm to 400 mm. The thickness of the support member 20 depends on the material, but can be, for example, 0.01 mm to 5 mm. By setting the thickness of the support member 20 within the above range, the electrode unit 30 can be pressed with a constant tension. Note that the support member 20 may be curved to the extent that the tension does not substantially change, depending on the shape of the head 99 and the condition of the hair.

[0150] Examples of materials that can be used for the support member 20 (film member) include resin members, metal members, and glass films. Examples of resin members include polyimide resin films, polyetherimide resin films, polyamideimide resin films, and other polyimide resin-based films; polyamide resin films, such as polyamide resin films; polyester resin films, such as polyester resin films; PET (polyethylene terephthalate) resin films; and PS (polystyrene) resin films. Among these, polyimide resin films are particularly preferred for their improved flexibility, elasticity, and heat resistance. Examples of metal members that can be used include aluminum foil and copper foil.

[0151] <Physical Properties of the Support Member 20> The physical properties of the support member 20 (Poisson's ratio, Young's modulus, maximum thickness, Young's modulus × thickness) are specified, for example, as follows. (Poisson's Ratio) The Poisson's ratio of the support member 20 is 0.15 to 0.4. The lower limit of the Poisson's ratio is preferably 0.2 or more, more preferably 0.25 or more. The upper limit of the Poisson's ratio is preferably 0.38 or less, more preferably 0.35 or less. By setting the Poisson's ratio of the support member 20 within the above range, the support member 20 is less likely to deform. That is, when the EEG measurement device 10 is attached to the head 99, a force acts in the direction of extension of the support member 20 when the electrode unit 30 is pressed against the head 99. In other words, tension acts. If the support member 20 is made of an elastic material such as rubber, the support member 20 may be inappropriately extended, which may cause the tension of the electrode unit 30 on the head 99 to change, resulting in uneven pressing force. As a result, the signal quality of the obtained electroencephalogram may be reduced. However, by setting the Poisson's ratio of the support member 20 within the above range, the force with which the electrode unit 30 presses against the head 99 can be controlled within a certain range, enabling stable electroencephalogram measurement.

[0152] (Young's Modulus) The Young's modulus (elastic modulus) of the support member 20 is 0.4 GPa to 150 GPa. The lower limit of the Young's modulus is preferably 3 GPa or more, and more preferably 5 GPa or more. The upper limit is preferably 140 GPa or less, and more preferably 135 GPa or less. By setting the Young's modulus of the support member 20 within the above range, the strength of the support member 20 can be maintained and deformation can be prevented.

[0153] (Young's modulus x thickness) The product of the Young's modulus (elastic modulus) and thickness of the material constituting the film member is 0.4 to 9.1 GPa·mm. Even if the material is easily deformed (i.e., a material with a small Young's modulus), as long as the thickness is above a certain level, the force with which the electrode unit 30 presses against the head 99 can be controlled within a certain range without substantial deformation. Furthermore, in the case of a hard material (i.e., a material with a large Young's modulus), the ability of the electroencephalogram measuring device 10 to conform to the shape of the head 99 is significantly reduced unless the thickness is made thin to a certain extent. Therefore, by setting the product of the Young's modulus (elastic modulus) and thickness within the above range, the force with which the electrode unit 30 attached to the support member 20 presses against the head 99 can be controlled within a certain range, thereby achieving stable electroencephalogram measurement.

[0154] <Mounting portion 70> The mounting portion 70 is attached to each of the longitudinal ends of the support member 20 (both left and right ends in Figures 1 and 2), and is placed between the support member 20 and a part of the subject that is different from the measurement part (here, the ear), and presses the electrode unit 30 against the head 99 with a predetermined electrode pressing force F.

[0155] Specifically, the attachment part 70 includes an adjustment part 50 and an ear attachment part 40, and has a string 45 connecting them.

[0156] The ear attachment unit 40 is attached to the ear of the subject. In this embodiment, the ear attachment unit 40 is attached by wrapping around the ear from below.

[0157] The adjustment units 50 are attached to both ends of the support member 20. The adjustment units 50 have a plate-like member 52 attached to the support member 20 and a locking unit 51 for fixing the length of the plate-like member 52.

[0158] The plate-like member 52 is a long strip with a plurality of rows of teeth. The locking portion 51 has an opening with a claw formed therein, through which the plate-like member 52 is inserted to lock it in a desired position. The locking portion 51 also has a release portion that works in conjunction with the claw to release the locked state. The material of the adjustment portion 50 is not particularly limited, but various plastics can be used. Nylon 66 is preferably used from the viewpoints of physical properties, processability, cost, etc.

[0159] As described above, according to this embodiment, in the EEG measuring device 10, the electrode units 30 are fixed to the support member 20 made of a film base material, forming a polygon with vertices at the electrode units 30 attached only to necessary locations. This allows the electrode units 30 to conform well to the shape of the head. Furthermore, by modeling the wearing state of the EEG measuring device 10 using the capstan equation, the electrode pressing force F applied by the electrode units 30 can be appropriately determined.

[0160] Second Embodiment A second embodiment will be described with reference to Figures 6 to 9. The differences between this embodiment and the first embodiment are: (1) a screw-fitting structure is used to attach the electrode unit 30 to the support member 20; (2) in accordance with the adoption of the screw-fitting structure, an electrode attachment portion 160 is provided instead of the recessed snap button 25 as a structure for attaching the electrode unit 30; and (3) the structure and installation position of the adjustment portion 150. Below, differences from the first embodiment will be mainly described, and similar components will be appropriately designated by the same reference numerals and description thereof will be omitted.

[0161] Fig. 6 is a schematic diagram showing the EEG measuring device 110 attached to a person's head 99, as viewed from the front. Fig. 7 is a plan view showing the EEG measuring device 110 when not attached to the head 99. Fig. 8 is a cross-sectional view showing the electrode unit 30 attached to the electrode attachment portion 160 of the support member 20.

[0162] <Electrode mounting portion 160> The support member 20 is provided with an electrode mounting portion 160 for mounting the electrode unit 30. The electrode mounting portion 160 has a mounting portion main body 161 that is circular in top view, and a female screw 162 provided in the center of the mounting portion main body 161.

[0163] The outer diameter of the attachment body 161 is set to be approximately the same as the outer diameter of the electrode unit 30. A circuit section 163 (preamplifier) ​​formed of a hard insulating substrate is mounted on the upper surface of the attachment body 161, and performs primary amplification of the brain waves acquired by the electrode unit 30. The upper surface of the attachment body 161 is covered with an insulating cover member as necessary.

[0164] A female screw 162 made of a conductive material is attached to the center of the attachment portion main body 161. The male screw type connection terminal 135 (protrusion 135b) of the electrode unit 30 is screw-fitted into the female screw 162.

[0165] <Male Screw-Type Connection Terminal 135> A male screw-type connection terminal 135 made of a conductive material is provided on the upper surface of the electrode unit 30 in place of the convex snap button 35 of the first embodiment.

[0166] The male screw-type connection terminal 135 has a disk-shaped portion 135a and a protrusion 135b extending from the center of the upper surface of the disk portion 135a. The protrusion 135b is formed in a cylindrical shape and has a male screw with a thread formed on its circumferential surface. The female screw 162 is connected to a circuit portion 163.

[0167] The electrode unit 30 is attached to the support member 20 by threadably engaging the female screw 162 with the male screw-type connection terminal 135 (i.e., the convex portion 135b). The electroencephalogram signal acquired by the electrode unit 30 is transmitted to the circuit section 163 from the male screw-type connection terminal 135 via the female screw 162. The electroencephalogram signal that has been primarily amplified by the circuit section 163 is output to an electroencephalogram display device or the like via a signal path not shown.

[0168] By using threaded fitting as the attachment method for the electrode unit 30 and the support member 20, the attachment portion can be stabilized and noise generation can be suppressed.

[0169] <Adjustment portion 150> Figure 9 shows the adjustment portion 150. Figure 9(a) is a side view, and Figure 9(b) is a plan view. As shown in Figure 6, the adjustment portion 150 is sewn to the support member 20 between electrode positions C3 and T3 and between electrode positions C4 and T4.

[0170] The adjustment unit 150 has a plate-like member 152 attached to the support member 20, and a locking unit 151 that slides the plate-like member 152 and fixes it at a desired position. The locking unit 151 is provided with a string attachment unit 154 to which the string 45 is attached.

[0171] Convex string guides 126 are provided on both longitudinal ends of the support member 20. The string guides 126 are provided with openings that communicate in the left-right direction, through which the string 45 is inserted. This ensures that the string 45 always passes through both ends of the base material 21, ensuring that the electroencephalogram measuring device 10 is worn properly.

[0172] The plate-like member 152 is a long, rail-like strip with a plurality of protrusions 152a arranged in a row. The locking portion 151 is slidably fitted into the rail formed by the protrusions 152a. The locking portion 151 has a locking mechanism 156 that prevents it from sliding. The non-slidable state is released by performing a predetermined operation on the locking mechanism 156 (for example, by pushing it sideways).

[0173] By sliding the locking portion 151 on the plate-like member 152, the distance between the ear attachment portion 40 attached to the string 45 and the support member 20 can be adjusted.

[0174] <Third Embodiment> A third embodiment will be described with reference to Figures 10 to 13. This embodiment differs from the first and second embodiments in that (1) the support member 220 is a linear member 221, and (2) the linear member 221 is configured to be removable. Below, the differences from the first and second embodiments will be mainly described.

[0175] Fig. 10 is a plan view of the EEG measuring device 210 of this embodiment. Fig. 11 is a front view of the EEG measuring device 210. Figs. 10 and 11 show the EEG measuring device 210 in a state where it is not attached to the head 99. Fig. 12 is a plan view focusing on the attachment mode of the support member 220 for two electrode units 30 at electrode positions Cz and C3. Fig. 13 shows a cross-sectional view of the electrode unit 30 in a state where it is attached to the electrode attachment portion 260.

[0176] The electrode units 30 are attached to electrode attachment parts 260 having a configuration similar to that of the electrode attachment part 160 shown in the second embodiment, and are supported by a support member 220. The support member 220 is provided with two parallel linear members 221 that are stretched between adjacent electrode units 30 (i.e., electrode attachment parts 260). In addition, attachment parts 270 are attached to the electrode attachment parts 260 at the left and right ends (electrode positions T3, T4), respectively.

[0177] <Electrode attachment section 260> As in the second embodiment, the electrode attachment section 260 has an attachment section main body 261 that is circular when viewed from above, a female screw 262 provided in the center of the attachment section main body 261, and a circuit section 163 that primarily amplifies the acquired brain waves.

[0178] <Connectors 225> The electrode attachment portion 260 has a plurality of connectors 225 for attaching the support member 220 (linear members 221).

[0179] On the top surfaces of the three central electrode mounting portions 260 (i.e., electrode positions Cz, C3, and C4), two connectors 265 are provided on the front and back sides of the right side in the same position in the left-right direction, and two connectors 265 are provided on the front and back sides of the left side in the same position in the left-right direction.

[0180] The two connectors 265 on the right side have openings facing rightward, allowing the connectors 225 provided on the linear member 221 to be inserted and removed, respectively. The two connectors 265 on the left side have openings facing leftward, allowing the connectors 225 provided on the linear member 221 to be inserted and removed, respectively.

[0181] On the top surface of the electrode attachment section 260 at the right end (electrode position T3), two connectors 265 are lined up on the left side in the drawing, one on the front side and one on the back side, and an attachment section 270 (adjustment section 250) is provided near the center on the right side. The two connectors 265 have openings facing left, and each allows the connector 225 provided on the linear member 221 to be inserted or removed.

[0182] On the top surface of the electrode attachment section 260 at the left end (electrode position T4), two connectors 265 are lined up on the right side in the drawing, one on the front side and one on the back side, and an attachment section 270 (adjustment section 250) is provided near the center on the left side. The two connectors 265 have openings facing right, and each allows the connector 225 provided on the linear member 221 to be inserted or removed.

[0183] <Attachment portion 270> Similar to the attachment portion 70 of the second embodiment, the attachment portion 270 has an ear attachment portion 240, an adjustment portion 250, and a string 245. In this embodiment, the attachment position of the adjustment portion 250 is the electrode attachment portion 260.

[0184] The adjustment section 250 has a locking section 251 attached to the electrode attachment section 260, and a plate-like member 252 whose position is fixed by the locking section 251. A string 245 is attached to the plate-like member 252.

[0185] By sliding the plate-like member 252, the distance between the ear attachment part 240 attached to the string 245 and the electrode attachment part 260 can be adjusted.

[0186] <Support Member 220 > The support member 220 has a linear member 221 and connectors 225 provided on both ends of the linear member 221 .

[0187] The linear member 221 refers to a linear member such as a string or wire. For example, an electric cable (such as a multi-core cable or a flat cable) can be used as the linear member 221. The length of the linear member 221 is set according to the electroencephalogram measurement position. The thickness of the linear member 221 needs only to be flexible enough to appropriately conform to the shape of the head when the electroencephalogram measurement device 210 is attached to the head 99 and electroencephalograms are measured, and strong enough to withstand continuous use without breaking.

[0188] The connectors 225 at both ends of the linear member 221 are attached to connectors 265 of the electrode attachment parts 260 to connect adjacent electrode attachment parts 260 (i.e., electrode units 30).

[0189] By using the linear members 221 as an electric cable, acquired electroencephalogram signals can be collected at a predetermined external output terminal (not shown). Furthermore, by using two parallel linear members 221 between adjacent electrode units 30, the posture of the electrode units 30 in contact with the head 99 can be stabilized. Furthermore, by making the linear members 221 detachable from the electrode attachment section 260, they can be replaced if some of the linear members 221 or the electrode attachment section 260 are damaged. Furthermore, by providing linear members 221 of different lengths, it is possible to set the inter-electrode distance according to the size of the subject's head 99, i.e., the optimal electrode position. The support member 220 may be fixed to the electrode attachment section 260 by soldering or the like.

[0190] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations can also be adopted.

[0191] Hereinafter, the present embodiment will be described in detail with reference to examples. However, the present embodiment is not limited to the description of these examples. The following examples correspond to the first and second embodiments, and confirmation was carried out regarding "verification of the support member (film substrate)" and "verification of modeling based on the capstan equation."

[0192] <<Verification of Support Member (Film Substrate)>> A total of seven samples from Examples 1 to 7 were evaluated for suitability as the support member 20. The evaluation criteria were rated on a three-point scale as follows: Evaluation A: When a constant tension (0.6 N) was applied, the electrode position shift was small (5 mm or less); Evaluation B: When a constant tension (0.6 N) was applied, the electrode position shift was within the allowable range (10 mm or less); Evaluation C: When a constant tension (0.6 N) was applied, the electrode position shift was outside the allowable range (more than 10 mm).

[0193] The materials of each sample in Examples 1 to 7 are as follows. Table 1 shows the physical properties (Poisson's ratio, Young's modulus, maximum thickness, Young's modulus × thickness). Example 1...PET (polyethylene terephthalate) resin Example 2...PI (polyimide) resin Example 3...aluminum foil Example 4...copper foil Example 5...PS (polystyrene) resin Example 6...PE (polyethylene) resin Example 7...glass film

[0194] In Examples 1 to 6, the electrode position shift when a constant tension was applied was small, and electroencephalograms could be stably acquired at the target position. In Example 7, the Young's modulus of the support member was smaller than in Examples 1 to 6, and the thickness was larger than in the other samples in order to suppress deformation, but the electrode position shift when a constant tension was applied was slightly larger.

[0195]

[0196] <<Verification of modeling based on the capstan equation>> The electroencephalogram measuring device shown in the embodiment was attached to a head model, and the electrode pressing force F was measured using a pressure sensor placed on the surface of the head model, and the measured value was compared with the calculated value obtained from the model based on the capstan equation.

[0197] The specific specifications of the electroencephalogram measuring device 10 are as follows: EEG measuring positions: 5 locations: T3, C3, Cz, C4, and T4 Electrode unit: base diameter 10 mm, base thickness 5 mm, protrusion height 5 mm, number of protrusions 7, inter-electrode distance 70 mm Supporting member (film substrate): PI resin Poisson's ratio 0.3 Young's modulus 3.4 GPa Maximum thickness 0.225 mm Instead of fixing to the ears with the ear attachment parts, a 200 g weight was attached to each end to simulate the wearing state of the electroencephalogram measuring device.

[0198] 14 shows a graph of the theoretical (calculated) and measured values ​​of the electrode pressing force F at five locations, T3, C3, Cz, C4, and T4. As can be seen from the graph, the theoretical and measured values ​​are almost identical, confirming the validity of the modeling.

[0199] This application claims priority based on Japanese Patent Application No. 2023-077092, filed May 9, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0200] 10, 110, 210 Electroencephalogram measuring device 20 Support member (film substrate) 25 Concave snap button 30 Electrode unit 31 Base 32 Protrusion 33 Conductive contact portion 34 Signal line portion 35 Convex snap button 40 Ear attachment portion 50, 150 Adjustment portion 70 Mounting portion 135 Male screw-type connection terminal 160, 260 Electrode attachment portion 161, 261 Mounting portion main body 162, 262 Female screw 220 Support member 221 Linear member 225, 265 Connector

Claims

1. An electroencephalogram measuring device comprising: a support member that is placed along the head of a subject; an electrode unit that is attached to the support member and contacts the scalp of the subject to acquire an electroencephalogram signal; and a support member that supports the placement of the support member on the head, An electroencephalogram measuring device in which the support member is composed of a ribbon-shaped or linear member.

2. The electroencephalogram measuring device according to claim 1 , wherein the support member is made of a non-stretchable material having flexibility such that it can deform to conform to the shape of the head.

3. 3. The electroencephalogram measuring device according to claim 1, wherein the support member, when configured as a ribbon-shaped member, has a film member disposed between adjacent electrode units.

4. 4. The electroencephalogram measuring device according to claim 3, wherein the Poisson's ratio of the material constituting the film member is 0.15 to 0.

4.

5. The electroencephalogram measuring device according to claim 3, wherein the product of the elastic modulus and thickness of the material constituting the film member is 0.4 to 9.1 GPa·mm.

6. 3. The electroencephalogram measuring device according to claim 1, wherein when the support member is constituted by a linear member, the linear member is disposed between the electrode units.

7. The electroencephalogram measuring device according to claim 6 , wherein the linear member is provided as at least two extending members spaced apart from each other, and the electrode unit is provided between the two members.

8. 3. The electroencephalogram measuring device according to claim 1, wherein the electrode unit has a base, a plurality of protrusions provided on the base, and an electrode portion provided on the protrusions and adapted to come into contact with a head.

9. The electroencephalogram measuring device according to claim 8 , wherein the convex portion is an elastic member.

10. 3. The electroencephalogram measuring device according to claim 1, wherein the support member is provided at an end of the support member, attached to the ear or chin, and supports the positioning of the support member to the shape of the head.

11. 3. An electroencephalogram measuring method for measuring electroencephalograms by attaching the electroencephalogram measuring device according to claim 1 or 2 to the head of a subject.