JP6927631B2 - Electrodes for EEG measurement and their manufacturing method - Google Patents

Description

The present invention relates to an electrode for measuring electroencephalogram and a method for manufacturing the same.

As the conventional electroencephalogram measurement electrode, a type in which a conductive paste is interposed between the subject's scalp and the electrode is often used. The conductive paste has the effect of fixing the position of the measurement site in addition to reducing the contact impedance between the scalp and the electrodes, but it requires removal after measurement, which complicates the work. ..

Therefore, in recent years, an electrode (dry electrode) capable of ensuring a low contact impedance without using a conductive paste has been developed. As the dry electrode, for example, a multi-pin type dry electrode used by attaching to a hair band (for example, Non-Patent Document 1) and a multi-pin type dry electrode used by attaching to a head cap (for example, Non-Patent Document 2) have been proposed. ing. In these dry electrodes, the multi-pin is made of a hard metal.

Further, in order to reduce the burden on the subject, an electroencephalogram measurement electrode (for example, Patent Document 1) in which a contact portion made of metal is provided at the tip of a protruding portion made of rubber, or a metal spring is used to make the metal. An electroencephalogram measuring electrode having a spherical tip that can be expanded / contracted, swung, and swiveled has been proposed (for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2013-111361 Japanese Unexamined Patent Publication No. 2013-240485

Manabu Honda, Strategic Creative Research Promotion Project CREST, Research Area "Advanced Integrated Sensing Technology", Research Project "Wearable Core Brain Function Integrated Sensing System to Create a Safe Information Environment for the Brain" g-tec active dry electrode "g.SAHARA", Internet <URL: http://www.gtec.at/Products/Electrodes-and-Sensors/g.SAHARA-Specs-Features>

However, since the multi-pins of the electrodes of Non-Patent Documents 1 and 2 are made of a hard metal, there is a problem that the subject feels uncomfortable and the burden on the scalp is large.

In the electrode of Patent Document 1, since a large amount of conductive material is blended in order to impart desired conductivity to the protruding portion made of rubber, the original flexibility and cushioning property of rubber are lowered and the electrode becomes hard. The hard protrusion leads to pain of the subject when it comes into contact with the scalp, and moreover, the adhesion to the scalp is poor, which makes it difficult to accurately measure the brain wave. Further, when an expensive conductive material is used, the manufacturing cost cannot be suppressed.

In the electrode of Patent Document 2, due to the complexity of the structure, poor continuity may occur at the contact point, and the electroencephalogram measurement may not be performed well. Moreover, since the structure is complicated, the manufacturing cost is high and it is not suitable for mass production.

When measuring an electroencephalogram with a conventional electrode for measuring an electroencephalogram, the hair becomes an obstacle and the resistance value rises. For this reason, accurate results cannot be obtained in the hair area. If the contact between the scalp contact portion of the electrode and the mounted area of the head is poor, it becomes difficult to obtain an accurate measurement result. In order to improve the accuracy of EEG measurement, there is a need for electrodes that can reliably contact and adhere to any region of the head.

Therefore, the present invention provides an electroencephalogram measuring electrode capable of contacting the scalp without using a conductive paste to sufficiently secure continuity, reducing the burden on the subject, and measuring the electroencephalogram with high accuracy, and a method for manufacturing the same. The purpose is.

The electrode for electroencephalogram measurement according to the present invention has a comb tooth row including a plurality of flexible comb teeth, and has a first layer along the longitudinal direction of the plurality of comb teeth and the first layer. An electroencephalogram measuring electrode including a second layer provided on one side surface, the first layer is more easily deformed than the second layer, and the second layer is a nanocarbon material. It is characterized by including.

The method for manufacturing an electrode for measuring brain waves according to the present invention includes a step of forming a base material along a longitudinal direction of the plurality of comb teeth having a comb tooth row including a plurality of flexible comb teeth. A step of cutting the tip portions of the plurality of comb teeth to form a first layer, and a protruding portion containing a nanocarbon material on one side surface of the first layer and protruding from the first layer. It is characterized by comprising a step of forming a second layer having on the tip side of the plurality of comb teeth.

According to the present invention, the electroencephalogram measurement electrode is provided with a second layer containing a nanocarbon material on one side surface of the first layer along the longitudinal direction of a plurality of flexible comb teeth. ing. The second layer has conductive paths inside and on the surface due to the nanocarbon material. When measuring the electroencephalogram, the surface of the second layer (scalp contact surface) comes into contact with the scalp of the subject, so that sufficient conduction can be ensured without using a conductive paste.

Since the plurality of comb teeth are flexible, they do not cause pain or other discomfort to the subject even when pressure is applied. The burden on the subject is reduced. The scalp contact surface makes good contact with the scalp as the plurality of comb teeth scrape the hair. Moreover, the first layer is more easily deformed than the second layer on the scalp contact surface side. The plurality of comb teeth can be reliably contacted and adhered to any area of the head on the scalp contact surface. As a result, the electroencephalogram measuring electrode of the present invention can measure the electroencephalogram with high accuracy.

It is a perspective view of the electrode for electroencephalogram measurement which concerns on this embodiment. It is a front view of the electrode for electroencephalogram measurement which concerns on this embodiment. It is an enlarged view of the region X in FIG. It is a top view of the electrode for electroencephalogram measurement which concerns on this embodiment. It is the schematic explaining the manufacturing process (1) of the 1st layer. It is the schematic explaining the manufacturing process (2) of the 1st layer. It is the schematic explaining the manufacturing process of the electrode for electroencephalogram measurement. It is the schematic which shows the structure of the electrode component for electrode contact resistance measurement.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1. 1. Overall Configuration As shown in FIG. 1, the electroencephalogram measurement electrode 10 has a support portion 14 and a comb tooth row 17 including a plurality of comb teeth 16 protruding from the support portion 14. The plurality of comb teeth 16 are flexible. The electroencephalogram measurement electrode 10 includes a first layer 22 along the longitudinal direction of the plurality of comb teeth 16 and a second layer 24 provided on one side surface of the first layer 22. The first layer 22 is more easily deformed than the second layer 24. The second layer 24 contains a nanocarbon material. In the present embodiment, also in the support portion 14, the second layer 24 is provided on one side surface of the first layer 22.

The first and second layers 22 and 24 have flexibility and cushioning properties. This imparts flexibility to the plurality of comb teeth 16. The first layer 22 is a molded body of a thermoplastic elastomer containing no nanocarbon material. The second layer 24 is a molded product using a thermoplastic elastomer as a base material. In the present embodiment, a polyamide-based thermoplastic elastomer is used as the thermoplastic elastomer.

The plurality of comb teeth 16 are inclined toward the first layer 22 from the middle in the length direction. The surface of the comb teeth 16 shown in FIG. 2 on the second layer 24 side is the scalp contact surface 18. In the second layer 24, the scalp contact surface 18 has conductivity because conductive paths made of the nanocarbon material are formed inside and on the surface. The thickness of the plurality of comb teeth 16 decreases from the base end 16a to the tip end 16b. The thickness d3 of the support portion 14 can be about 2.0 to 3.0 mm.

The thicker the first layer 22, the more flexible the comb teeth 16 are and the more easily they are deformed. In this case, the conductivity required for the electroencephalogram measurement electrode 10 tends to decrease. When the thickness of the first layer 22 is about 30 to 80% of the thickness of the comb teeth 16, both flexibility and conductivity can be achieved.

An enlarged view of the region X on the tip side of the plurality of comb teeth 16 is shown in FIG. The second layer 24 has a protruding portion 24a protruding toward the tip end side from the first layer 22. A filling portion 26 made of the same material as the second layer 24 is provided on the protruding portion 24a. The filling portion 26 is formed between the tip of the first layer 22 and the tip of the second layer 24. By having the projecting portion 24a and the filling portion 26, it is possible to prevent the first layer 22 from peeling from the second layer 24. When the length d7 of the protruding portion 24a is 1 mm or more, the peeling suppressing effect is sufficiently exhibited.

The size of the electroencephalogram measurement electrode 10 will be described with reference to FIG. The support portion 14 can have, for example, a width d1 of about 10 to 15 mm and a length d2 of about 10 to 20 mm. The comb tooth 16 can have, for example, a length d4 of about 15 to 30 mm and a width d5 of about 0.5 to 1.5 mm. In this case, the distance d6 between the adjacent comb teeth 16 can be, for example, about 1.0 to 2.0 mm.

The tips 16b of the plurality of comb teeth 16 preferably have a rounded shape having no corners. The number of comb teeth 16 is not limited, and may be appropriately set according to the size of the support portion 14 and the comb teeth 16.

In the present embodiment, carbon nanotubes (hereinafter referred to as CNT) are used as the nanocarbon material contained in the second layer 24. CNTs are preferably blended in an amount of 3-30 wt% of the base material in order to form conductive paths inside and on the surface of the second layer 24 without compromising the elasticity of the thermoplastic elastomer as the base material. .. The second layer 24 is preferably a volume resistivity of not more than 100 [Omega · cm.

As described above, the electroencephalogram measurement electrode 10 of the present embodiment is composed of a first layer 22 and a second layer 24. The first layer 22 is a molded product of a thermoplastic elastomer. The second layer 24 is a molded product using a thermoplastic elastomer as a base material, and contains a nanocarbon material. Since the thermoplastic elastomer and the nanocarbon material are both non-metals, the electrode for electroencephalogram measurement of the present embodiment does not include a metal member.

2. Manufacturing Method Next, a manufacturing method of the electroencephalogram measurement electrode 10 will be described. The electroencephalogram measurement electrode 10 can be manufactured by producing the first layer 22 and integrating the second layer 24 with the first layer 22 while forming the second layer 24 by insert molding.

<Preparation of the first layer>
The first layer can be made by injection molding. As shown in FIG. 5, a mold 50 having a predetermined mold core 52 and a mold cavity 54 is used. The mold cavity 54 side is in a closed state. A predetermined thermoplastic elastomer is poured into the mold core 52 to prepare the base material 22A of the first layer. The injection molding conditions can be appropriately selected depending on the type of thermoplastic elastomer and the like.

As shown in FIG. 6, the base material 22A has a tip portion cut to a predetermined length (d7). This gives the first layer 22. The length d7 to be cut is preferably 1 mm or more. Since the first layer 22 is a molded body of the thermoplastic elastomer, it has the original physical characteristics of the thermoplastic elastomer (for example, hardness, flexural modulus, etc.).

<Preparation of the second layer>
First, the CNT and the thermoplastic elastomer are kneaded by a twin-screw extruder to prepare a CNT kneading raw material. The thermoplastic elastomer used here is preferably the same as that used for making the first layer 22, but may be different. CNTs are produced by a general arc discharge method, a vapor phase growth method, a laser evaporation method, or the like. For example, Co, using a catalyst containing a metal such as Mg, CO gas and H ₂ gas may be used CNT produced by vapor deposition of a raw material.

Prior to the preparation of the CNT kneading raw material, the CNT may be pretreated with a mixed acid, if necessary. As the mixed acid, for example, a mixed solvent in which nitric acid and sulfuric acid are mixed at a volume ratio of 1: 1 can be used. CNT is added to the mixed solvent, stirred, and CNT is isolated and dispersed by irradiating with ultrasonic waves. Then, the CNT is taken out by vacuum filtration, and the CNT surface is neutralized with aqueous ammonia or the like. The surface of the neutralized CNT is washed with pure water and then dried to obtain a powdery CNT.

The obtained CNT is melt-kneaded with a thermoplastic elastomer by a twin-screw extruder to obtain a CNT-kneaded raw material. The conditions for melt-kneading can be appropriately selected depending on the type of thermoplastic elastomer and the like. The concentration of CNT is preferably about 3 to 30 wt% of the thermoplastic elastomer. The concentration of CNT is more preferably 10 wt% or more, and most preferably 20 wt% or more of the thermoplastic elastomer.

A mold cavity 56 as shown in FIG. 7 is used to prepare the second layer 24. The first layer 22 is arranged on the mold core 52 side, and the CNT kneading raw material is poured into the second layer 24 to be integrated with the first layer 22. By including CNT, the second layer 24 is conductive. In this way, the electroencephalogram measurement electrode 10 in which the conductive second layer 24 is provided on one side surface of the first layer 22 is obtained.

The first and second layers 22 and 24 all have flexibility and cushioning properties due to the use of a thermoplastic elastomer. However, since the second layer 24 contains CNT, the hardness of the second layer 24 is higher than that of the first layer 22. Since the first layer 22 has the original physical characteristics of the thermoplastic elastomer, it is more flexible and more easily deformed than the second layer 24 containing CNT.

As shown in FIG. 3, in the region X on the distal end side of the electroencephalogram measurement electrode 10, there is a protruding portion 24a in which the second layer 24 has a length d7 of 1 mm or more and protrudes from the first layer 22. A filling portion 26 is provided on the protruding portion 24a. The filling portion 26 is a molded body of a thermoplastic elastomer containing CNT, similarly to the second layer 24.

A plurality of the electroencephalogram measuring electrodes 10 of the present embodiment can be used as a headset by attaching a plurality of electrodes 10 to, for example, a headband or a head cap so that the scalp contact surface 18 (see FIG. 2) is in contact with the scalp. The plurality of electroencephalogram measuring electrodes 10 included in the headset do not necessarily all have a uniform shape and size, and the shape and size can be arbitrarily changed as needed.

3. 3. Action and effect In the electroencephalogram measurement electrode 10 configured as described above, a plurality of comb teeth 16 project in a row from the support portion 14, and a comb tooth row 17 is formed. When the electroencephalogram measuring electrode 10 is used, the comb dentition 17 is inserted into the hair from the tips 16b of the plurality of comb teeth 16 along the scalp contact surface 18 along the scalp. By the plurality of comb teeth 16 scraping the hair, the scalp contact surface 18 can avoid the hair and come into contact with the scalp.

The scalp contact surface 18 of the electroencephalogram measurement electrode 10 is the surface of the second layer 24 containing the nanocarbon material, and a conductive path is formed. When using the electroencephalogram measuring electrode 10 of the present embodiment, the scalp is in contact with the conductive path. Since the conductive path is also formed inside the second layer 24, the conduction between the electroencephalogram measurement electrode 10 and the head of the subject is ensured without using the conductive paste. The contact impedance can be lowered to an extremely low level, and the electroencephalogram measurement electrode 10 can accurately detect a weak electric signal from the head.

Moreover, the first and second layers 22 and 24 constituting the electroencephalogram measurement electrode 10 have flexibility and cushioning properties, and the plurality of comb teeth 16 are flexible. When measuring the electroencephalogram, the subject does not feel uncomfortable even if the plurality of comb teeth 16 along the comb dentition 17 come into contact with the head of the subject and pressure is applied. The electroencephalogram measurement electrode 10 of the present embodiment can reduce the burden on the subject.

In the case of this embodiment, the opposite side of the scalp contact surface 18 is a first layer 22 containing no nanocarbon material. The first layer 22 is more easily deformed than the second layer 24 containing the nanocarbon material. When the scalp contact surface 18 comes into contact with the scalp, the plurality of comb teeth 16 can be easily deformed depending on the contact state. By deforming the plurality of comb teeth 16, the electroencephalogram measurement electrode 10 can be reliably contacted and adhered to any region of the head on the scalp contact surface 18, so that the electroencephalogram can be measured with high accuracy. be.

CNTs as nanocarbon materials are not contained in the first layer 22 opposite the scalp contact surface 18. As a result, the deformability of the first layer 22 as described above is ensured. Moreover, since the amount of CNT used can be minimized, the manufacturing cost can be reduced.

The electroencephalogram measurement electrode 10 according to the present embodiment includes a first layer 22 made of a thermoplastic elastomer molded body and a second layer 24 made of a thermoplastic elastomer molded body containing CNT. Yes, no metal parts are included. By not including the metal member, various advantages can be obtained.

For example, image information is acquired by X-ray computed tomography (CT) or magnetic resonance imaging (MRI) while the electroencephalogram measurement electrode 10 according to the present embodiment is attached to the head. However, no artifacts due to metal members occur. By using the electroencephalogram measurement electrode 10 of the present embodiment, it is possible to simultaneously acquire image information by X-ray CT, MRI, or the like and electroencephalogram by the electroencephalogram electrode.

Further, since the metal member is not included, the electroencephalogram measurement electrode 10 can be used for a subject having a metal allergy. The electroencephalogram measurement electrode 10 according to the present embodiment can be disposable and is excellent in hygiene.

4. Examples Hereinafter, examples of electrodes for measuring brain waves will be described, but the present invention is not limited to the following examples.

[Example]
In the example, a first layer made of a polyamide-based thermoplastic elastomer is formed, and then a second layer is formed by insert molding using a CNT kneading raw material to prepare an electrode for electroencephalogram measurement.

<Preparation of the first layer>
A polyamide-based thermoplastic elastomer (Pevax 7033, manufactured by Arkema Co., Ltd.) was used to prepare a base material for the first layer by a method as described with reference to FIG. The tip portion of the obtained base material was cut by 1 mm to obtain a first layer. The first layer has a shore A hardness of about 75 and a flexural modulus of about 12 MPa.

<Preparation of the second layer>
First, CNTs were produced by a general thermal CVD method using iron as a catalyst. The obtained CNT was melt-kneaded with a polyamide-based thermoplastic elastomer (Pevax 7033, manufactured by Arkema Co., Ltd.) in a twin-screw extruder. In this way, the CNT kneading raw material was prepared. The CNT concentration was 12 wt%.

A mold core and a mold cavity as described with reference to FIG. 7 were prepared, and the first layer prepared above was arranged in the mold core. The CNT kneading raw material was poured into the mold cavity to prepare a second layer integrated with the first layer. In this way, an electroencephalogram measurement electrode 10 provided with a conductive second layer 24 on one side surface of the first layer 22 as shown in FIG. 1 was obtained. In the electroencephalogram measurement electrode 10, a plurality of comb teeth 16 project from the support portion 14.

The first layer 22 is a molded product of a polyamide-based thermoplastic elastomer, and the second layer 24 is a molded product using a polyamide-based thermoplastic elastomer as a base material. As a result, the first and second layers 22 and 24 have flexibility and cushioning properties, and the plurality of comb teeth 16 are imparted with flexibility. The second layer 24 has conductivity due to CNT. On the other hand, the first layer 22 is more easily deformed than the second layer 24 because it does not contain CNT.

In the electroencephalogram measurement electrode 10 of the embodiment, the width d1, the length d2, and the thickness d3 of the support portion 14 are 11 mm, 13.8 mm, and 2.5 mm, respectively, and the comb teeth 16 have a length d4 and a width d5. And the spacing d6 was 17.3 mm, 0.7 mm, and 1.2 mm, respectively (see FIGS. 2 and 4). The thickness of the first layer 22 was 1.25 mm at the base end 14a of the support portion 14 and 0.25 mm at the tip end side of the comb teeth 16.

<Measurement of electrode contact resistance>
An electrode component for measurement was prepared using the electroencephalogram measurement electrode 10 of the example, and the electrode contact resistance was measured for the forehead and the hair. For the measurement, a wireless bioelectric signal measuring device (Polymate Mini) manufactured by Miyuki Giken and an active electrode (dish electrode) were used.

Specifically, as shown in FIG. 8, the active electrode 34 to which the conducting wire 32 is connected is attached to the scalp contact surface 18 side of the electroencephalogram measurement electrode 10 by using the terminal retainer 36, and the measurement electrode component 30 Was produced. The electrode contact resistance was measured by bringing the scalp contact surface 18 into contact with the forehead or the hair. The forehead was measured by applying a polishing gel before the measurement to reduce the contact resistance. The electrode contact resistance at the forehead was 20 kΩ, and the electrode contact resistance at the hair was 50 kΩ to 150 kΩ.

For comparison, electrode contact resistance was measured at the forehead and hair by the same method using only the active electrode 34 (comparative example). For the forehead, 20 kΩ, which was similar to that in the example, was obtained. However, for the hair part, it was a large value of 300 kΩ or more. Since the comparative example is only the active electrode 34, the hair cannot be avoided. It was found that the active electrode 34 could not accurately measure the electroencephalogram of the hair portion because the hair became an obstacle and the electrode contact resistance became high.

In the electroencephalogram measurement electrode 10 of the embodiment, the plurality of comb teeth 16 reach the scalp while scraping the hair of the hair portion, and the scalp contact surface 18 avoids the hair and contacts the scalp. Since the scalp contact surface 18 is the surface of the second layer 24 having conductivity, sufficient conductivity can be ensured without the conductive paste. By using the electroencephalogram measurement electrode 10 of the example, a low resistance value can be obtained even in the hair portion.

Since the electroencephalogram measurement electrode 10 is composed of a molded body of thermoplastic elastomer (first layer 22) and a molded body using the thermoplastic elastomer as a base material (second layer 24), it is used for measuring brain waves in the examples. The electrode 10 has flexibility and cushioning properties. Since the plurality of comb teeth 16 have flexibility, the effect of reducing the burden on the subject can be obtained.

Moreover, in the electroencephalogram measurement electrode 10 of the embodiment, the first layer 22 on the opposite side of the scalp contact surface 18 is more easily deformed than the second layer 24. When the scalp contact surface 18 comes into contact with the scalp, the plurality of comb teeth 16 can be easily deformed according to the contact state, so that the electroencephalogram measurement electrode 10 can be reliably formed on the scalp contact surface 18 in any region of the head. Can be in close contact with. The electroencephalogram measuring electrode 10 can measure an electroencephalogram with high accuracy.

5. Modifications The present invention is not limited to the above embodiment, and can be appropriately modified within the scope of the gist of the present invention.

The first and second layers 22 and 24 may have flexibility and cushioning properties, and an elastic body such as a thermoplastic elastomer other than the polyamide-based thermoplastic elastomer, resin, or rubber can be used as a raw material. .. The first layer 22 and the second layer 24 can be produced by the above-mentioned method using an arbitrary elastic body as a raw material.

Examples of thermoplastic elastomers other than polyamide-based thermoplastic elastomers include urethane-based thermoplastic elastomers (TPU), olefin-based thermoplastic elastomers (TPO), styrene-based thermoplastic elastomers (TPS), and ester-based thermoplastic elastomers (TPC). , Polyamide-based thermoplastic elastomer (TPAE), polyvinyl chloride-based thermoplastic elastomer (TPVC) and the like.

Examples of the resin include acrylonitrile styrene (AS) resin, acrylonitrile butadiene (ABS) resin, epoxy resin, tetrafluoroethylene / ethylene copolymer (ETFE), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), and hexafluoro. Propropylene / ethylene copolymer (EFEP), polyvinylidenefluorolide (PVDF), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene / ethylene copolymer (ECTFE), polycaproamide (nylon 6), polyhexa Methylene adipamide (nylon 66), polytetramethylene adipamide (nylon 46), polyhexamerylene sebacamide (nylon 610), polyhexamelylene dedecamide (nylon 612), polydodecaneamide (nylon 12) , Polyundecaneamide (Nylon 11), Polyhexamethylene terephthalamide (Nylon 6T), Polyxylylene adipamide (Nylon XD6), Polynonamethylene terephthalamide (Nylon 9T), Polyundecane methylene terephthalamide (Nylon 11T), Polydecamethylene decaneamide (nylon 1010), polydecamethylene dodecaneamide (nylon 1012) amide-based elastomer (TPA), polybutylene terephthalate (PBT), polybutylene naphthalate (PBN), polyethylene naphthalate (PEN), polycarbonate ( PC), linear low density polyethylene (LLDPE), ultra low density polyethylene, low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), crosslinked polyethylene, ethylene / vinyl acetate copolymer (PC) EVA), ethylene / vinyl alcohol copolymer (EVOH), butenediol / vinyl alcohol copolymer (BVOH), polyvinyl alcohol (PVA), polybutene (PB), modified polyphenylene ether (modified PPE), liquid crystal polymer (LCP) , Cycloolefin Copolymer (COC), Polyether Ketone (PEK), Polyglycolic Acid (PGA), Polyallylate (PAR), Polymethylpentene (PMP), Polyether Ether Ketone (PEEK), Polyether Salfone (PES) , Polyethylene terephthalate (PET), phenolic resin (PF), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA) ), Polyethylene (PI), Polyetherimide (PEI), Acrylic resin (PMMA), Polyacetal (POM), Polypropylene (PP), Polyphenylene sulfide (PPS), Polystyrene (PS), Polysulfone (PSU), Polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC) and the like.

Examples of rubber include natural rubber (NR), ethylene / propylene rubber (EPM, EPDM), chloroprene rubber (CR), butyl rubber (IIR), polyurethane rubber (U), silicone rubber (VMQ, FVMQ), and acrylic rubber (ACM). ), Epichlorohydrin rubber (ECO), Fluorine rubber (FKM, FEPM, FFKM), Nitrile rubber (NBR), Hydrogenated nitrile rubber (H-NBR), Chlorinated polyethylene (CPE), Chlorosulfonated polyethylene (CSM), Examples thereof include butadiene rubber (BR) and styrene / butadiene rubber (SBR).

CNTs as nanocarbon materials are not limited to tubular ones. A CNT whose shape has changed due to heating or the like may be used. Nanocarbon materials other than CNTs, such as graphene, can also be used. Graphene is a nanocarbon material having high conductivity similar to CNT. A graphene kneading raw material can be prepared by the same method as described above except that the CNT is changed to graphene, and the second layer 24 can be formed using the raw material. It is also possible to use CNT and graphene in combination.

The first layer 22 may be injection-molded using a mold core having a target shape. By using a mold core whose tip is as short as a predetermined length (d7), the step of cutting the tip portion of the base material 22A of the first layer molded in advance can be omitted.

As long as sufficient adhesiveness is obtained between the first layer 22 and the second layer 24, the tips of the second layer 24 and the first layer 22 may coincide with each other. An electrode for electroencephalogram measurement having such a structure can be produced, for example, by insert molding using the base material 22A of the first layer that has been injection molded as it is.

In some cases, the filling portion 26 above the protruding portion 24a of the second layer 24 may be omitted. An electroencephalogram measuring electrode having such a shape can be produced by using a mold cavity having an appropriate shape when the first layer 22 having a cut tip portion is arranged on a mold core and insert-molded.

In the electroencephalogram measurement electrode 10, the plurality of comb teeth 16 projecting in a row from the support portion 14 do not necessarily have to be inclined toward the first layer 22 from the middle in the length direction. Unlike the shape shown in FIG. 2, the base end 14a of the support portion 14 to the tip 16b of the comb teeth 16 may be in a straight line. The plurality of comb teeth 16 may have a uniform thickness from the base end 16a to the tip end 16b.

The electroencephalogram measurement electrode 10 can have an arbitrary size suitable for electroencephalogram measurement. The length d4, width d5, and interval d6 of the comb teeth 16 may be appropriately set according to the type of elastic body to be used, the width d1 and the length d2 of the support portion 14, and the like.

The support portion 14 of the electroencephalogram measurement electrode 10 does not necessarily have to have a rectangular shape defined by a width d1 and a length d2. The support portion 14 and the plurality of comb teeth 16 can have any shape as long as the original elasticity of the thermoplastic elastomer can be maintained and the scalp contact surface 18 does not prevent the scalp contact surface 18 from coming into contact with the scalp.

The support portion 14 does not necessarily have a two-layer structure consisting of a first layer 22 and a second layer 24 as a whole, and the base end 14a side may be only the second layer 24. The entire support portion 14 may also be composed of the second layer 24.

If consideration for artifacts is not required, even if a part of the electroencephalogram measurement electrode 10 contains a metal member such as a metal plate, as long as the flexibility and cushioning property of the electroencephalogram measurement electrode 10 are not impaired. good. For example, a metal plate may be arranged on the surface of the support portion 14 on the second layer 24 side. By providing the metal plate, the electric signal can be easily transmitted, and the measurement accuracy can be further improved.

In the above embodiment, the first layer 22 does not contain CNT as a nanocarbon material, but is not limited thereto. The first layer 22 may contain a nanocarbon material as long as it can maintain the property of being more flexible and more easily deformed than the second layer 24.

10 Electrodes for EEG measurement 16 Comb teeth 17 Comb dentition 22 First layer 24 Second layer

Claims (9)

It has a comb dentition including a plurality of flexible comb teeth, and a first layer along the longitudinal direction of the plurality of comb teeth and a second layer provided on one side surface of the first layer. Electroencephalogram measurement electrode with a layer of
The surface of the second layer is the scalp contact surface,
The first layer is more easily deformed than the second layer,
The second layer, viewed contains nano carbon material,
The second layer is an electrode for electroencephalogram measurement, which has a protrusion protruding toward the tip side from the first layer on the tip side of the plurality of comb teeth. Wherein on the projecting portion, the second layer and the brain wave measurement electrode according to claim 1, wherein the compensation unit made of the same material, characterized in that it is provided. The electrode for electroencephalogram measurement according to claim 1 or 2 , wherein the plurality of comb teeth are inclined toward the side of the first layer from the middle in the length direction. The electrode for electroencephalogram measurement according to any one of claims 1 to 3 , wherein the first layer is made of a molded product of resin, thermoplastic elastomer, or rubber. The electrode for electroencephalogram measurement according to any one of claims 1 to 4 , wherein the second layer is a molded product using a resin, a thermoplastic elastomer, or rubber as a base material. The electrode for electroencephalogram measurement according to any one of claims 1 to 5 , wherein the second layer has a volume resistivity of 100 Ω · cm or less. The electrode for electroencephalogram measurement according to any one of claims 1 to 6 , wherein the nanocarbon material is selected from carbon nanotubes and graphene. The electrode for electroencephalogram measurement according to any one of claims 1 to 7 , wherein the first layer and the second layer do not contain a metal member. A step of forming a base material along a longitudinal direction of the plurality of comb teeth having a comb dentition including a plurality of flexible comb teeth.
A step of cutting the tip portions of the plurality of comb teeth to form a first layer, and
On one side surface of the first layer includes a nano-carbon material, have a protruding portion protruding from the first layer on the distal end side of the plurality of comb teeth, the second surface thereof is scalp contact surface A method for manufacturing an electrode for electroencephalogram measurement, which comprises a step of forming a layer of the above.

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