Electrode unit for brain wave measurement and brain wave measurement device

Abstract

To provide a technology of dispersing a force of pressing a brain wave electrode against scalp at the time of pressing the brain wave electrode against the scalp.SOLUTION: An electrode unit for brain wave measurement 190 includes: a base part 122; an electrode part (electrode protrusion 123) projecting from one surface of the base part 122; and a plurality of elastic members (cushion protrusions 142) provided around the electrode part (electrode protrusion 123) and not functioning as the electrode part (electrode protrusion 123). The elastic member (cushion protrusion 142) is higher than the electrode part (electrode protrusion 123) with reference to the one surface of the base part 122.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electrode unit for measuring electroencephalograms and an electroencephalogram measuring device including such an electrode unit. [Background technology]

[0002] In electroencephalogram (EEG) measurements, electrodes are placed on the head to conduct electrical measurements.

[0003] Patent Document 1 describes measuring electroencephalograms by bringing the tips of electrode pins supported by an elastic member into contact with the scalp. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2020-000268 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with the structure described in Patent Document 1, the subject may feel uncomfortable when the EEG electrodes are pressed against the scalp, and there has been a need for a technology that can distribute the force of pressing the EEG electrodes against the scalp.

[0006] The present invention provides a technique for dispersing the pressing force when pressing an EEG electrode against the scalp. [Means for solving the problem]

[0007] According to the present invention, the following techniques are provided. 1. A base; an electrode portion protruding from one surface of the base portion; a plurality of elastic members provided around the electrode portion and not functioning as the electrode portion; and An electrode unit for measuring electroencephalograms, wherein the elastic member is higher than the electrode portion with respect to the one surface of the base portion. 2. The electrode unit according to claim 1, wherein the elastic member is non-conductive. 3. The electrode unit according to 1. or 2., wherein the elastic member bends in a direction away from the electrode unit when the electrode unit is pressed against the head. 4. An electrode unit according to 3., wherein the side of the elastic member facing the electrode portion has a slope that faces away from the electrode unit as it moves away from the base. 5. The elastic member has a truncated cone shape, 4. The electrode unit according to 4, wherein the surface obtained by cutting the pyramid is the inclined surface. 6. The electrode unit according to 1. or 2., wherein the electrode portion and the elastic member are provided as separate bodies. 7. The electrode unit according to 1. or 2., wherein the electrode portion and the elastic member are integrally formed. 8. The electrode unit according to 1. or 2., wherein the elastic member is made of resin. 9. An electrode unit according to 1. or 2., wherein the pressure required for bending the elastic member until the height thereof reaches the tip of the electrode portion is 3 kPa or more and 30 kPa or less. 10. A support attached to the head; the electrode unit according to 1. or 2. attached to the support; An electroencephalogram measuring device having: [Effects of the Invention]

[0008] According to the present invention, a technique can be provided for dispersing the force with which an EEG electrode is pressed against the scalp when the EEG electrode is pressed against the scalp. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating a partial cross section of an electroencephalogram measuring device according to a first embodiment. [Figure 2] 1 is a perspective view illustrating an electroencephalogram measuring device according to a first embodiment. [Figure 3]1 is a diagram illustrating a state in which the support body according to the first embodiment is worn on a person's head. [Figure 4] 3A and 3B are diagrams illustrating an example of an inner state of the support body according to the first embodiment. [Figure 5] 2 is a cross-sectional view showing the state of the EEG electrode member when the EEG measuring device according to the first embodiment is worn on the head. FIG. [Figure 6] 1 is a diagram illustrating a partial cross section of an electroencephalogram measuring device in a state in which a holding member and an electroencephalogram electrode member according to a first embodiment have been removed from a support body. [Figure 7] FIG. 2 is a cross-sectional view of the electrode unit according to the first embodiment. [Figure 8] FIG. 1 is a perspective view of an electrode unit according to a first embodiment. [Figure 9] FIG. 2 is an exploded cross-sectional view of the electrode unit according to the first embodiment. [Figure 10] FIG. 2 is a cross-sectional view of an EEG electrode member according to the first embodiment. [Figure 11] 5A to 5C are diagrams illustrating changes in the shape of a cushion part when the electrode unit according to the first embodiment is pressed against the scalp. [Figure 12] FIG. 10 is a diagram illustrating a partial cross section of an electroencephalogram measuring device according to a second embodiment. [Figure 13] FIG. 10 is a cross-sectional view showing the state of the EEG electrode member when the EEG measuring device according to the second embodiment is worn on the head. [Figure 14] FIG. 10 is a diagram showing a state in which a liquid is supplied to the scalp through a tube in a state in which an electroencephalogram measuring device according to a second embodiment is worn on the head. [Figure 15] FIG. 10 is a cross-sectional view of an electrode unit according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, like components are designated by like reference numerals, and the description thereof will be omitted as appropriate.

[0011] First Embodiment <Summary> Fig. 1 is a diagram illustrating a partial cross section of an electroencephalogram (EEG) measuring device 10 according to an embodiment. Figs. 2 to 4 are diagrams illustrating an overall view of the EEG measuring device 10. Fig. 2 is a perspective view of the EEG measuring device 10 as seen from above. Fig. 3 is a front view of the EEG measuring device 10 worn on the head. Fig. 4 is a diagram illustrating the inside of a support 110 of the EEG measuring device 10 (the side where the head 20 is inserted).

[0012] The EEG measuring device 10 comprises a support 110, a support elastic member 130, a holding section 180, and an electrode unit 190. The electrode unit 190 comprises an EEG electrode member 120 and a cushion section 140. EEGs are measured by bringing the electrode unit 190 (EEG electrode member 120) of the EEG measuring device 10 into contact with the head 20 (scalp 22). The electrode unit 190 is attached to the support elastic member 130 via the holding section 180 and is held by the support 110.

[0013] In the electrode unit 190, the cushion part 140 is arranged around the EEG electrode member 120, and when the EEG electrode member 120 is brought into contact with the scalp 22, the cushion part 140 comes into contact first and bends to a certain extent. The cushion part 140 is formed of a material softer than the EEG electrode member 120, and when the electrode unit 190 is pressed to bring the EEG electrode member 120 into contact with the scalp 22, the pressing force is distributed not only to the EEG electrode member 120 but also to the cushion part 140.

[0014] Although details will be described later, the support 110 is, as an example, a helmet type that is worn on the head 20, and has a support through-hole 114 that penetrates from the inside to the outside, and a support elastic member 130 that is embedded in the support through-hole 114. The EEG electrode member 120 is held on a bottom surface 132 of the support elastic member 130 via a holding portion 180.

[0015] The support elastic member 130 is provided with an elastic member recess 131 recessed from the surface toward the bottom. The elastic member recess 131 communicates with the support through-hole 114. A finger or the like can be inserted into the elastic member recess 131 through the support through-hole 114 to operate the support elastic member 130, or the holding portion 180 (holding portion recess 188) attached to the support elastic member 130 to adjust the orientation of the EEG electrode member 120, etc.

[0016] In the examples of Figs. 2 to 4, the support 110 is helmet-shaped. When the support 110 is helmet-shaped, the support 110 has a recess into which the head 20 is inserted. The EEG measuring device 10 is configured so that one or more EEG electrode members 120 come into contact with the head 20 (scalp 22) when the helmet-shaped support 110 is attached to the head 20. The EEG measuring device 10 may include a belt 170 for fixing the support 110 to the head 20, as shown in Fig. 4.

[0017] Hereinafter, the side of the support 110 facing the head 20 (scalp 22) will be referred to as the inside of the support 110, and the side opposite the inside will be referred to as the outside of the support 110. In FIG. 1, the direction from the inside to the outside of the support 110 is referred to as the z direction. The x direction, y direction, and z direction are perpendicular to each other. The z direction is generally the normal direction to the scalp 22. Note that the x direction, y direction, and z direction can be defined as different directions for each EEG electrode member 120 in the EEG measurement device 10.

[0018] In the examples of FIGS. 2 to 4, the support 110 holds a plurality of EEG electrode members 120. With the support 110 attached to the head 20, each EEG electrode member 120 can be brought into contact with a predetermined position on the head 20. Then, EEG signals are measured using the plurality of EEG electrode members 120. For example, the support 110 can hold seven EEG electrode members 120. The positions of the seven EEG electrode members 120 may correspond to positions F3, F4, C3, C4, P3, Pz, and P4 in the International 10-20 electrode placement system. The number and positions of the EEG electrode members 120 provided on the support 110 are not particularly limited and may be set according to the application, etc. The EEG signals measured by each EEG electrode member 120 are transmitted to the signal processing unit 160.

[0019] In the example of FIG. 1, the electroencephalogram measuring device 10 further includes a support elastic member 130 and a holding unit 180. The support elastic member 130 is elastically deformable. The support elastic member 130 has a recess (hereinafter referred to as an "elastic member recess 131") recessed from the outside toward the inside. In this embodiment, at least a part of the bottom surface of the elastic member recess 131 has a second through-hole (hereinafter also referred to as an "elastic member through-hole 135") that penetrates the support elastic member 130. In this embodiment, a configuration is exemplified in which substantially the entire bottom surface of the elastic member recess 131 is formed as the elastic member through-hole 135. In the following description, the elastic member recess 131 and the elastic member through-hole 135 are considered to be the same unless otherwise specified.

[0020] The shape of the support 110 is determined, for example, based on an average head shape. However, head shapes vary greatly from person to person, and an element that can absorb these differences is necessary. In an EEG measurement device 10 in which the EEG electrode member 120 is held on the support 110 via a support elastic member 130, the support elastic member 130 elastically deforms when the support 110 is attached to the head 20. This allows the EEG electrode member 120 to be stably brought into contact with the scalp, allowing EEG measurement, even if there are individual differences in head shape (irregularities and surface angles).

[0021] As described above, a finger 99 or the like is inserted into the support 110 through the support through-hole 114 provided in the covering member 112 of the support 110 to operate the support elastic member 130 (elastic member recess 131) and the holding member 180 (holding member recess 188). Since a structure protruding from the inside of the support 110 to the outside is not required to adjust the orientation of the EEG electrode member 120, the center of gravity can be stabilized when attached to the head 20. In addition, the subject can lie down while wearing the support 110, which reduces noise caused by body movement, etc. Furthermore, EEG measurement can be performed while the subject is moving around.

[0022] Furthermore, the electrode unit 190 is detachable from the support 110. This allows the EEG electrode member 120 to be replaced as needed, or different types of EEG electrode member 120 to be used for different measurements. Each component of the electroencephalogram measuring device 10 will be described in detail below.

[0023] <Details of each component of the EEG measuring device> Fig. 5 is a cross-sectional view showing the state of the electrode unit 190 in a state where the electroencephalogram measuring device 10 is worn on the head, and corresponds to Fig. 1. Fig. 6 is a view showing a state where the electrode unit has been removed from Fig. 1.

[0024] <Support> The support 110 has a shape that can cover at least a portion of the head 20. The support 110 may be made of, for example, cloth or rubber, as long as it can be attached to the head 20. The support 110 may be, for example, helmet-shaped, hat-shaped, or band-shaped. In this embodiment, the support 110 includes a base 111 and a covering member 112. The base 111 is located on the head 20 side when the support 110 is attached to the head 20. The covering member 112 is located on the opposite side from the head 20 side when the support 110 is attached to the head 20.

[0025] The base 111 is made of, for example, polystyrene foam. The base 111 has a plurality of (seven in this example) holes 115 that penetrate vertically at positions corresponding to F3, F4, C3, C4, P3, Pz, and P4 in the International 10-20 electrode arrangement method. Support elastic members 130 are housed in the holes 115. The covering member 112 is made of, for example, resin. The covering member 112 is harder than the base 111 and can protect the head 20. However, the support 110 does not necessarily have to include the covering member 112.

[0026] <Supporting member elastic member> The support elastic member 130 is housed in a hole 115 provided in the base 111 of the support 110. The outer shape and size of the support elastic member 130 are approximately the same as the inner shape and size of the hole 115 provided in the support 110, and the support elastic member 130 is fitted into the hole 115 of the support 110.

[0027] When the support body 110 is not attached to the head 20, the support body elastic member 130 may fill the entire hole 115 provided in the support body 110 except for the first through-hole 131. The covering member 112 is provided with a support through-hole 114. The elastic member recess 131 provided in the support elastic member 130 and the support through-hole 114 provided in the covering member 112 are in communication with each other.

[0028] 6, the diameter d2 of the support through-hole 114 is preferably larger than the diameter d1 of the elastic member recess 131. By making the diameter d2 of the support through-hole 114 larger in this way, it becomes easier to operate the elastic member recess 131 and the holding portion recess 188 (cone-shaped recess). As a result, it becomes easier to adjust the orientation, etc. of the EEG electrode member 120.

[0029] The support elastic member 130 is made of an elastic material, such as one or more selected from the group consisting of urethane sponge, polyethylene sponge, polypropylene sponge, and silicone rubber sponge. The elastic material may be a foam, and examples of the foam include low-resilience sponge and low-resilience elastic foam.

[0030] The support elastic member 130 may be configured without a spring. When a spring is used, the repulsive force of the spring increases in proportion to the deformation of the spring. Therefore, when the deformation is large, excessive repulsive force is generated, and the subject is likely to feel pain. On the other hand, when a foam elastic material is used, there is a range of displacement in which the repulsive force does not increase much (is not proportional) with an increase in the deformation. By configuring the support elastic member 130 so that it can be used within this range of displacement, an appropriate repulsive force can be obtained even if the deformation varies depending on the position of the EEG electrode member 120.

[0031] The hardness H of the elastic material, measured by JIS K 6400-2·A method, is, for example, 10 N or more and 200 N or less. From the viewpoint of further reducing the burden on the subject, the hardness H is preferably 150 N or less, and more preferably 100 N or less. Furthermore, from the viewpoint of more stably pressing the EEG electrode member 120 against the scalp 22, the hardness H is preferably 30 N or more, and more preferably 50 N or more.

[0032] The thickness t of the support elastic member 130 is, for example, 10 mm or more and 100 mm or less when the support 110 is not attached to the head 20. Here, the thickness t is the thickness of the support elastic member 130 in a direction perpendicular to the bottom surface 132 of the support elastic member 130 that faces the head 20. The support elastic member 130 is fixed to the support 110 at one end, and the thickness t of the support elastic member 130 is variable depending on the force received in the thickness direction. Specifically, the support elastic member 130 is fixed to the support 110 at the surface (top surface 133) opposite the bottom surface 132. The thickness t of the support elastic member 130 is preferably 20 mm or more and 60 mm or less when the support 110 is not attached to the head 20. The lower limit of the thickness t is preferably 25 mm or more, more preferably 30 mm or more. The upper limit of the thickness t is preferably 55 mm or less, more preferably 50 mm or less. By setting the thickness t in this manner, it is possible to compress appropriately according to the shape of the head 20, and the EEG electrode member 120 can be pressed appropriately against the scalp 22 while minimizing discomfort to the person being measured.

[0033] The area of ​​the bottom surface 132 of the support elastic member 130 facing the head is, for example, 3 cm 2 More than 25cm 2 The lower limit is preferably 5 cm. 2 More preferably, 7 cm 2 This ensures an appropriate size for the EEG electrode member 120, and allows for a stable posture (direction). The upper limit is preferably 20 cm. 2 less than 15cm, more preferably 2 The shape is as follows. This prevents the orientation of the EEG electrode member 120 from moving too much, making adjustment difficult. The shape of the bottom surface is not particularly limited. Examples of the shape of the bottom surface include a circle, a square, an egg shape, an ellipse, etc. A circle is preferable from the viewpoint of making it easier to rotate the EEG electrode member 120. On the other hand, a circle is preferable when it is not desirable to rotate the EEG electrode member 120.

[0034] <Holding part> The holding part 180 is provided on the bottom surface 132 of the support elastic member 130. The holding part 180 holds the electrode unit 190 on the surface (bottom surface 183) opposite to the support elastic member 130. In other words, the electrode unit 190 is attached to the support elastic member 130 via the holding part 180. The holding part 180 may be detachable from the support elastic member 130.

[0035] The holding portion 180 integrally includes a base portion 181 and a protrusion 182. The holding portion 180 is made of, for example, hard plastic, and the base portion 181 and the protrusion 182 are molded at the same time.

[0036] Base 181 is substantially disk-shaped (flange-shaped) with a predetermined thickness. Base 181 has conductive portion 164 and circuit 162. Specifically, a bottom surface 183 of base 181 has first accommodating portion 185 recessed to accommodate conductive portion 164, and second accommodating portion 186 recessed to accommodate circuit 162. First accommodating portion 185 is provided at the center of the disk shape. The position of second accommodating portion 186 is not particularly limited, but is provided so that the accommodated circuit 162 can function appropriately. The function of circuit 162 will be described later.

[0037] The protrusion 182 is cylindrical and protrudes upward (in the z direction) from the center of the upper surface 184 of the base 181 (i.e., the center of the disk shape). The protrusion 182 is fitted into the elastic member recess 131 (elastic material through-hole 135) of the support elastic member 130 from the bottom side of the elastic member recess 131.

[0038] A holding portion recess 188 recessed in the vertical direction is provided on the upper surface of the convex portion 182. The holding portion recess 188 overlaps with the elastic member recess 131 (elastic member through-hole 135). As a result, the holding portion recess 188 can be operated by a finger 99 or the like from outside the support body 110 via the support body through-hole 114 and the elastic member recess 131.

[0039] The holding portion recess 188 has, for example, a shape (so-called cone-shaped) in which the cross section becomes smaller from the support elastic member 130 toward the electrode unit 190. By using such a shape, the holding portion recess 188 can be easily operated with the finger 99. The shape of the holding portion recess 188 is not limited to a cone-shaped shape, and may be any shape that is suitable for operation with a finger.

[0040] <Circuit> The circuit 162 includes, for example, a preamplifier that amplifies the electrical signal from the EEG electrode member 120, and is also called an active electrode. The circuit 162 is electrically connected to the conductive portion 164 by a wiring 163, and acquires the EEG signal from the EEG electrode member 120 via the conductive portion 164. The circuit 162 performs amplification processing according to predetermined settings, and transmits the signal to the signal processing unit 160 via a wiring 165.

[0041] <Electrode unit> FIG. 7 is a cross-sectional view of the electrode unit 190. FIG. 8 is a perspective view of the electrode unit 190. FIG. 9 is an exploded cross-sectional view of the electrode unit 190. The electrode unit 190 has an EEG electrode member 120 and a cushion portion 140. The EEG electrode member 120 and the cushion portion 140 are provided separately. The EEG electrode member 120 and the cushion portion 140 are used assembled together. Because the EEG electrode member 120 and the cushion portion 140 are provided separately, EEG electrode members 120 and cushion portions 140 of different specifications can be used in combination. Furthermore, if damage occurs to either the EEG electrode member 120 or the cushion portion 140, the damaged member can simply be replaced.

[0042] <Electroencephalogram electrode materials> The EEG electrode member 120 includes an electrode body 125, a conductive member 124, and wiring 127. The electrode body 125 has a cylindrical base 122 and an electrode protrusion 123 protruding from the lower surface (hereinafter also referred to as the "protrusion forming surface 126") of the base 122. The conductive member 124 is attached to an upper surface 128 of the base 122.

[0043] <Conductive materials> The conductive member 124 is, for example, a conductive metal and has a first portion 124a and a second portion 124b. The first portion 124a and the second portion 124b are integrally formed. Examples of such metals that can be used include copper, aluminum, silver, and alloys thereof.

[0044] The first portion 124a is columnar (cylindrical). A screw groove is provided on the outside of the first portion 124a. The second portion 124b is, for example, disk-shaped. When the EEG electrode member 120 is housed in the electrode placement section 144 of the cushion section 140, the second section 124b abuts against the inner top surface 145 of the electrode placement section 144, and the first section 124a protrudes from the through-hole 149 of the cushion section 140. When the electrode unit 190 is attached to the holding section 180, the first section 124a is threadably fitted into the conductive section 164 of the holding section 180.

[0045] <Electrode body> 10 is a cross-sectional view of the EEG electrode member 120. The electrode body 125 comprises a cylindrical base 122 and one or more electrode protrusions 123 provided on the base 122.

[0046] The electrode protrusion 123 has a first portion 123a, a conductive portion 123b, and a second portion 123c. A plurality of electrode protrusions 123 are provided on the surface of the base 122 opposite to the conductive member .

[0047] The base 122 and the first portion 123a are integrally formed by a rubber-like elastic body. Ten or more electrode protrusions 123 may be provided. The shape of the first portion 123a is, for example, a cone or a pyramid such as a polygonal pyramid. The conductive portion 123b is provided so as to cover the first portion 123a. The tip of the first portion 123a is covered with the second portion 123c. The second portion 123c is a spherical member made of a gel-like material (also called hydrogel) containing water inside, and is attached so as to pierce the tip portion of the first portion 123a.

[0048] When the EEG electrode member 120 is pressed against the head 20 to measure EEG, the second portion 123c comes into contact with the head 20. At this time, electrolytes (generally salt) from the scalp 22 are taken up by the second portion 123c. As a result, the EEG electrode member 120 and the scalp 22 are electrically connected. The shape of the second portion 123c is not limited to a sphere. The gel material constituting the second portion 123c is not particularly limited as long as it can absorb sufficient water and has sufficient strength and flexibility when pressed against the head 20, but for example, an acrylic hydrogel or a silicone hydrogel can be used.

[0049] The materials of the base 122 and the first portion 123a will be described. The base 122 and the first portion 123a are configured to have a rubber-like elastic body. Specific examples of the rubber-like elastic body include rubber and thermoplastic elastomer (also simply referred to as "elastomer (TPE)"). An example of rubber is 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).

[0050] The conductive portion 123b is formed using a paste containing a highly conductive metal, such as copper, silver, gold, nickel, tin, lead, zinc, bismuth, antimony, or an alloy thereof.

[0051] Wiring 127 connected to conductive portion 123b is provided inside first portion 123a. Wiring 127 electrically connects conductive portion 123b and conductive member 124. Wiring 127 may be made of, 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.

[0052] By screwing the first portion 124a of the conductive member 124 into the conductive portion 164 of the holding portion 180, the EEG electrode member 120 is attached to the conductive portion 164 together with the cushion portion 140. In this way, the electrode unit 190, the EEG electrode member 120, is attached to the support elastic member 130.

[0053] <Cushion part> As shown in FIGS. 7 to 9, the cushion part 140 has a base part 141, a cushion protrusion part 142, and an electrode placement part 144.

[0054] The base 141 has a substantially cylindrical shape. An electrode placement section 144 that is cylindrically recessed toward the upper side as viewed in the figure is provided in the center of a main surface 148 on the lower side as viewed in the figure. The electrode placement section 144 has dimensions that allow the base 122 of the EEG electrode member 120 to be fitted into it. In other words, it can be said that the outer diameter of the base 122 of the EEG electrode member 120 and the inner diameter of the electrode placement section 144 are substantially the same. A through-hole 149 that penetrates the top surface 146 is provided in the center of the circular shape of the bottom surface of the electrode placement section 144. When the EEG electrode member 120 is accommodated in the electrode placement section 144, the first portion 124a of the conductive member 124 penetrates the through-hole 149.

[0055] A plurality of cushion protrusions 142 are provided on the main surface 148 of the base 141 around the periphery of the electrode placement portion 144. Specifically, the plurality of cushion protrusions 142 are arranged in a ring shape so as to surround the electrode placement portion 144. Note that, as an example, the plurality of cushion protrusions 142 are arranged in a single layer with no gaps between them, but they may be arranged in two or more layers, and a certain distance may be provided between adjacent cushion protrusions 142.

[0056] <Cushion protrusion> The cushion protrusion 142 is integrally formed with the base 141. The cushion protrusion 142 does not function as an electrode. Specifically, the cushion protrusion 142 is made of a non-conductive elastic material and does not acquire EEG. Resin can be used as the non-conductive elastic material, and specifically, as an example, the rubber-like elastic material exemplified as the material for the base 122 and first portion 123a of the EEG electrode member 120 can be used. The base 122 and first portion 123a of the EEG electrode member 120 and the base 141 and cushion protrusion 142 of the cushion member 140 may be made of the same material or different types of materials.

[0057] The cushion protrusions 142 bend in a direction away from the electrode protrusions 123, specifically outward, when the electrode unit 190 is pressed against the head 20. In order to achieve this outward bending function, the inclined surfaces 143 are surfaces that face the electrode protrusions 123 and that face in a direction away from the electrode protrusions 123 as they move away from the base 141.

[0058] The inclined surface 143 may be either a flat surface or a curved surface. If the inclined surface 143 is a curved surface, it may be either a concave or convex surface, or may have irregularities. In this embodiment, the cushion protrusion 142 has, as an example, a shape (flat surface) obtained by diagonally cutting the tip of a cone. The surface created when cutting is the inclined surface 143. In addition, in this embodiment, a configuration in which a circular cone is used as the cone is exemplified, but the cone may also be a polygonal pyramid such as a triangular pyramid or a square pyramid. In addition, the cone may be a right cone (rectangular cone) in which the foot of a perpendicular line drawn from the apex to the base coincides with the center of gravity of the base, or an oblique cone (oblique cone) in which the apex and the center of gravity of the base do not coincide. In this embodiment, the inclined surface 143 has, as an example, a shape obtained by diagonally cutting the tip of an oblique cone in which the apex of the cone is offset outward from the center of gravity of the base. When the electrode unit 190 is pressed against the scalp 22, the contact area of ​​the slope 143 increases as it gradually bends outward, thereby preventing the pressure acting on the scalp 22 by the cushion part 140 from becoming excessively large.

[0059] <Relationship between the height of the electrode convex part and the cushion convex part> 7, with the convex portion forming surface 126 of the base 122 of the EEG electrode member 120 as a reference (height P0), the height (P2) of the cushion convex portion 142 is higher than the height (P1) of the electrode convex portion 123. In other words, when the position of the tip of the cushion convex portion 142 is compared with the position of the tip of the electrode convex portion 123, the position of the tip of the cushion convex portion 142 is higher (farther away) from the convex portion forming surface 126 of the base 122. Therefore, when the electrode unit 190 is pressed against the scalp 22, the cushion portion 140 first comes into contact with the scalp 22, and as it is pressed further, the electrode convex portion 123 comes into contact with the scalp 22. The difference (P2-P1) between the height (P2) of the cushion protrusion 142 and the height (P1) of the electrode protrusion 123 is, for example, 0.5 mm or more and 10 mm or less. The lower limit of the difference is preferably 1 mm or more, and more preferably 2 mm or more. The upper limit of the difference is preferably 8 mm or less, and more preferably 6 mm or less. By setting the difference within this range, a good balance can be achieved between dispersing the force pressing the electrode unit 190 to the cushion part 140 and applying an appropriate load from the EEG electrode member 120 to the scalp 22.

[0060] Referring to Figure 11, the deformation of the cushion part 140 when the electrode unit 190 is pressed against the scalp 22 will be described. Figure 11(a) shows a state in which the tip of the cushion protrusion 142 just contacts the scalp 22. At this time, the electrode unit 190 (EEG electrode member 120) is not pressed against the scalp 22. In other words, the pressure acting on the electrode protrusion 123 is 0 kPa.

[0061] 13(a), when the electrode unit 190 is gradually pressed down, the cushion portion 140 gradually bends outward (in the direction away from the EEG electrode member 120). Accordingly, the contact area between the inclined surface 143 and the scalp 22 gradually increases. When the electrode unit 190 is pressed down further, the electrode unit 190 is pressed down, and the tip (second portion 123c) of the electrode convex portion 123 comes into contact with the scalp 22, as shown in FIG. 13(b).

[0062] The pressure applied until the cushion protrusions 142 bend until their height reaches the tip of the electrode protrusions 123, i.e., the pressure when the electrode protrusions 123 in FIG. 13(b) contact the scalp 22, is 3 kPa or more and 30 kPa or less. The lower limit of the pressure is preferably 3 kPa or more, and more preferably 5 kPa or more. By setting the lower limit in this range, the pressure acting on the EEG electrode member 120 when the electrode unit 190 is pressed against the scalp 22 can be dispersed to the cushion portion 140 (cushion protrusions 142). The upper limit is preferably 25 kPa or less, and more preferably 20 kPa or less. Setting the upper limit in this range prevents the cushion portion 140 from becoming too hard, and can prevent the cushion portion 140 from causing pain or discomfort to the subject. The pressure is measured, for example, by placing the electrode unit 190 on a non-deformable flat surface or a curved surface that simulates the shape of the head so that the tip of the cushion portion 140 is in contact with the surface, gradually applying a load to the electrode unit 190, and measuring the load when the electrode protrusion 123 contacts the flat surface and the area where all of the slopes 143 are in contact with the flat surface. The pressure is calculated by dividing the measured load by the area. An example of a pressure measurement device that can be used is the "Surface Pressure Distribution Measurement System I-SCAN" manufactured by Nitta Corporation. This device can measure the contact area and total load value.

[0063] <Electrical connections in the EEG measuring device> The electrical connections in the electroencephalogram measuring device 10 will be described below. The electroencephalogram measuring device 10 further includes wiring 163, 165, 166, a circuit 162, a signal processing unit 160, and a reference potential measuring wiring 161 (see FIG. 4). Of these, the conductive portion 164, wiring 165, 166, and circuit 162 are provided for each electroencephalogram electrode member 120. The wiring 163 and circuit 162, together with the conductive portion 164, are fixed to the holding portion 180.

[0064] When the scalp 22 comes into contact with the second portion 123c, an electrical signal from the scalp 22 is transmitted to the conductive member 124 via the second portion 123c, the conductive portion 123b, and the wiring 127. The electrical signal obtained in each EEG electrode member 120 in this manner is sent from the conductive member 124 of the EEG electrode member 120 to the signal processing unit 160 via the conductive portion 164, the wiring 163, the circuit 162, and the wiring 165.

[0065] The signal processing unit 160 is connected to a circuit 162 of the EEG electrode member 120 (holding unit 180), and acquires data measured by the electrode unit 190 via the circuit 162. The signal processing unit 160 performs processes such as amplification of the electrical signal of the EEG, analog-to-digital conversion, and frequency filtering. The signal processing unit 160 can also record the EEG signal data obtained by performing these processes in a recording unit provided within the signal processing unit 160. The signal processing unit 160 can also transmit the EEG signal data to an external device via wired or wireless communication.

[0066] It is preferable that the signal processing unit 160 has a built-in battery. This eliminates the need to connect a power line to the signal processing unit 160 to supply power. This in turn allows the subject to move and be active to a certain degree during measurement. It also makes it possible to prevent noise that depends on the frequency of the power supply. The reference potential measurement wiring 161 connects the signal processing unit 160 to a reference electrode (not shown). The reference electrode is an electrode for obtaining a reference potential that serves as a reference for measuring EEG signals. The reference electrode is attached, for example, with a clip to the earlobe or the top of the outer ear, or attached around the bone on the back side of the outer ear, to obtain the reference potential.

[0067] <How to use the EEG measuring device> The method of using the electroencephalogram measuring device 10 configured as described above will be described below. First, as shown in Fig. 3, the support 110 with the electroencephalogram electrode members 120 attached thereto is attached to the head 20. The electroencephalogram electrode members 120 are provided on the bottom surface 132 side of the support elastic member 130 via a holding portion 180.

[0068] At this time, as shown in Fig. 5, for example, the support elastic member 130 contracts in the thickness direction depending on the state of the head 20, and the EEG electrode member 120 is pressed against the scalp 22. That is, the support elastic member 130 deforms depending on the position and angle of the scalp 22 relative to the support 110. Also, the EEG electrode member 120 is pressed against the scalp 22 by a force depending on the elasticity of the support elastic member 130. That is, as the support elastic member 130 contracts, the position and angle of the tip of the EEG electrode member 120 relative to the support 110 change to fit the shape of the head 20.

[0069] If there is any discomfort in the contact state between the EEG electrode member 120 and the scalp 22, a finger 99 or the like can be inserted through the support through-hole 114 to manipulate the elastic material through-hole 135 of the support elastic member 130 or the holding portion recess 188 of the holding portion 180, thereby adjusting the orientation of the EEG electrode member 120. By performing such manipulation, the hair on the scalp 22 can be parted, improving the contact state between the EEG electrode member 120 and the scalp 22. At this time, the vibration unit 190 may be vibrated. Vibrating the vibration unit 190 can part the hair and improve the contact state between the EEG electrode member 120 and the scalp 22.

[0070] Furthermore, the cushion protrusions 142 of the cushion part 140 are bent in a direction away from the electrode protrusions 123, specifically outward. This allows the force with which the EEG electrode member 120 presses the scalp 22 to be distributed to the cushion part 140 as well, thereby preventing the subject from feeling pain or discomfort.

[0071] <Second embodiment> <Summary> The second embodiment will be described with reference to FIGS. Fig. 12 is a diagram illustrating a partial cross section of the electroencephalogram measuring device 10. Fig. 13 is a cross section showing the state of the electrode unit when the electroencephalogram measuring device 10 is worn on the head. Fig. 14 is a diagram showing the state in which the liquid 30 is supplied to the scalp 22 through the tube 151 when the electroencephalogram measuring device 10 is worn on the head. Fig. 15 is a cross section of the electrode unit 190.

[0072] In the second embodiment, an electrode unit 190 is adopted in which an EEG electrode member 120 and a cushion portion 140 are integrally formed, and an example is given of a configuration in which a tube 151 is inserted through a support member through-hole 114 of a support member 110 and a liquid 30 is supplied to the scalp 22 through an electrode through-hole 121 of an EEG electrode member 120. The EEG electrode member 120 and the cushion section 140 being integrally formed means that the EEG electrode member 120 and the cushion section 140 are inseparable, for example, that the EEG electrode member 120 and the cushion section 140 are molded simultaneously. Therefore, when they are molded simultaneously, there is generally no clear boundary between the EEG electrode member 120 and the cushion section 140. Below, differences from the first embodiment will be described, and descriptions of the same configurations and functions will be omitted as appropriate.

[0073] The EEG electrode member 120 is provided with an electrode through-hole 121 that penetrates from the support 110 toward the head 20. The holding portion 180 has a holding portion through-hole 189 on the bottom surface thereof that communicates with the electrode through-hole 121.

[0074] As described in the first embodiment, for example, the holding portion recess 188 has a shape (so-called mortar shape) in which the cross section becomes smaller from the support elastic member 130 toward the EEG electrode member 120. By adopting such a shape, the holding portion recess 188 can be easily operated with the finger 99. Furthermore, when inserting the tube 150 into the holding portion through-hole 189, the tube 150 is guided into the holding portion through-hole 189 by the slope of the holding portion recess 188, making insertion easier.

[0075] With this configuration, the support through-hole 114, the elastic member recess 131, the holding portion through-hole 189, and the electrode through-hole 121 communicate with each other. A tube 151 is inserted into the support through-hole 114, the elastic member recess 131, the holding portion through-hole 189, and the electrode through-hole 121, and a liquid 30 (see FIG. 14, etc.) that improves electrical contact between the scalp 22 and the EEG electrode member 120 is supplied.

[0076] <Electroencephalogram electrode materials> In the second embodiment, the EEG electrode member 120 further includes an electrode body 125, a conductive member 124, wiring 127, and a cover 129. The electrode body 125 includes a base 122 and one or more electrode protrusions 123 provided on the base 122. The electrode through-hole 121 is provided in the base 122.

[0077] As in the first embodiment, the conductive member 124 is, for example, a conductive metal and has a first portion 124a and a second portion 124b. The first portion 124a and the second portion 124b are integrally formed. Examples of such metals that can be used include copper, aluminum, silver, and alloys thereof.

[0078] The first portion 124a is tubular. As shown in Fig. 15, a through hole 121a provided in the conductive member 124 and a through hole 122a provided in the base portion 122 communicate with each other, and these through holes 121a and 122a form an electrode through hole 121. A thread groove is provided on the outside of the first portion 124a.

[0079] The second portion 124b is, for example, disk-shaped. In the example of Fig. 15, the cover 129 covers a part of the conductive member 124 and a part of the base 122. The cover 129 is made of, for example, resin and is insulating. The base 122 is fixed to the main surface 124c of the second portion 124b.

[0080] As in the first embodiment, the electrode protrusion 123 has a first portion 123a, a conductive portion 123b, and a second portion 123c. A plurality of electrode protrusions 123 are provided on the surface of the base 122 opposite to the conductive member 124. The base 122 and the first portion 123a are integrally formed by a rubber-like elastic body.

[0081] The cushion portion 140 has a plurality of cushion protrusions 142. The cushion protrusions 142 are formed in a convex shape on the protrusion forming surface 126 of the base portion 122. The cushion protrusions 142 and the base portion 122 are formed integrally. The plurality of cushion protrusions 142 are provided in a ring shape so as to surround the electrode protrusion 123.

[0082] The shape of the cushion protrusion 142 is the same as in the first embodiment, and is, for example, a shape obtained by cutting the tip of a cone at an angle. The surface created when cutting is the slope 143. The cushion protrusion 142 does not function as an electrode. Specifically, the cushion protrusion 142 is made of a non-conductive elastic material and does not acquire brain waves. For example, the electrode protrusion 123 has a conductive portion 123b and wiring 127, but the cushion protrusion 142 does not have a configuration that provides such a function.

[0083] <Pipes, injection parts> The structure for supplying liquid 30 to scalp 22 via tube 151 will be described. Liquid 30 is, for example, an auxiliary liquid containing an electrolyte. Injection member 152 is, for example, a syringe and has a liquid storage portion. Tube 151 is made of, for example, metal. With tube 151 attached to injection member 152, it is inserted into holder through-hole 189 and electrode through-hole 121. A structure for limiting the insertion depth of tube 151 is provided at the lower end of injection member 152 or the outer periphery of tube 151. When fully inserted, tube 151 penetrates base 122, but the tip of tube 151 is positioned above (in the +Z direction) the lower end of electrode protrusion 123. This prevents tube 151 from coming into contact with scalp 22. Liquid 30 extruded from injection member 152 is supplied to scalp 22 through tube 151.

[0084] When the tube 151 is inserted into the electrode through-hole 121 of the EEG electrode member 120, the height of the tube 151 protruding from the base 122 is smaller than the height of the electrode protrusion 123 protruding from the base 122. This prevents the tip of the tube 151 from touching the scalp 22 and causing injury.

[0085] <How to use the EEG measuring device> The method of using the electroencephalogram measuring device 10 configured as above will be described below. First, as in the first embodiment, the support 110 with the EEG electrode members 120 attached thereto is attached to the head 20 as shown in Fig. 3. The EEG electrode members 120 are provided on the bottom surface 132 side of the support elastic member 130 via a holding part 180.

[0086] 13, the support elastic member 130 contracts in the thickness direction depending on the state of the head 20, and the EEG electrode member 120 is pressed against the scalp 22. Also, the cushion protrusion 142 of the cushion part 140 bends in a direction away from the electrode protrusion 123, specifically outward.

[0087] If there is any discomfort in the contact state between the EEG electrode member 120 and the scalp 22, insert a finger 99 or the like through the support member through-hole 114 and operate the elastic material through-hole 135 of the support member elastic member 130 or the holding portion recess 188 of the holding portion 180 to adjust the orientation of the EEG electrode member 120, etc.

[0088] Next, as shown in FIG. 14 , the operator attaches the tube 151 to the EEG measurement device 10. Specifically, the tube 151 is passed through the support through-hole 114, the elastic member recess 131, and the holder through-hole 189, and then inserted into the electrode through-hole 121 of the EEG electrode member 120. The operator manipulates the injection member 152 to supply the liquid 30 (here, an auxiliary liquid, as an example) filled inside the injection member 152 from the tip of the tube 151 to the scalp 22, wetting the scalp 22. The auxiliary liquid is not particularly limited as long as it can reduce the electrical resistance between the EEG electrode member 120 and the scalp 22, and includes, for example, an electrolyte. However, it is also possible to perform EEG measurement using the EEG measurement device 10 without supplying the auxiliary liquid. The operator then removes the tube 150 and begins the electroencephalogram measurement.

[0089] According to this embodiment, the EEG measurement device 10 includes an EEG electrode member 120 having an electrode through-hole 121. A tube 151 is inserted through the electrode through-hole 121, allowing for efficient supply of auxiliary liquid to the area where the EEG electrode member 120 and the scalp 22 come into contact. Furthermore, auxiliary liquid can be supplied immediately before measurement after the EEG electrode member 120 is brought into contact with the scalp 22. Therefore, a low-viscosity liquid can be used as the auxiliary liquid. For example, if the auxiliary liquid is applied before placing the EEG electrode member on the head, there is a risk that the auxiliary liquid will run off or evaporate before measurement begins, necessitating the use of a paste- or gel-like auxiliary liquid. When using a paste-like auxiliary liquid, the extremely high viscosity of the auxiliary liquid necessitates the time-consuming task of manually brushing aside hair to apply it. Furthermore, when using a gel-like auxiliary liquid, the auxiliary liquid may be difficult to reach the scalp due to the influence of hair, and excessive application can lead to dripping and short-circuiting between the electrodes. On the other hand, these concerns are eliminated when auxiliary liquid can be supplied immediately before measurement. According to the electroencephalogram measuring device 10 of this embodiment, it is possible to inject a small amount of auxiliary liquid close to the scalp by previously parting the hair by manipulating the support elastic member 130 and the holding unit 180. Furthermore, by using an auxiliary liquid with a low viscosity equivalent to that of water, it is even less susceptible to the influence of hair, and contact resistance can be significantly reduced with a small amount of liquid.

[0090] The features of the first and second embodiments can be briefly summarized as follows. 1. a base 122; an electrode portion (electrode protrusion 123) protruding from one surface (protrusion forming surface 126) of the base portion 122; a plurality of elastic members (cushion protrusions 142) provided around the electrode portions (electrode protrusions 123) and not functioning as the electrode portions (electrode protrusions 123); and Electrode unit 190 for measuring electroencephalograms, in which the elastic member (cushion protrusion 142) is higher than the electrode portion (electrode protrusion 123) with respect to the one surface (protrusion forming surface 126) of the base portion 122 as a reference. 2. The electrode unit 190 according to 1., wherein the elastic member (cushion protrusion 142) is non-conductive. 3. The electrode unit 190 described in 1. or 2., wherein when the electrode unit 190 is pressed against the head, the elastic member (cushion convex portion 1420) bends in a direction away from the electrode portion (electrode convex portion 123, EEG electrode member 120). 4. An electrode unit 190 described in 3., wherein the side of the elastic member (cushion convex portion 142) facing the electrode portion (electrode convex portion 123) has a slope 143 that faces in a direction away from the electrode unit (electrode convex portion 123) as it moves away from the base 122 (convex portion forming surface 126). 5. The elastic member (cushion protrusion 142) has a shape of a cone with the tip cut off. 4. The electrode unit 190 according to claim 4, wherein the surface obtained by cutting the pyramid is the inclined surface 143. 6. The electrode unit 190 according to 1 or 2, wherein the electrode portion (electrode protrusion 123) and the elastic member (cushion protrusion 142) are provided as separate bodies. 7. The electrode unit 190 according to 1 or 2, wherein the electrode portion (electrode protrusion 123) and the elastic member (cushion protrusion 142) are integrally provided. 8. The electrode unit 190 according to 1. or 2., wherein the elastic member (cushion protrusion 142) is made of resin. 9. An electrode unit 190 described in 1. or 2., wherein the pressure required for the elastic member (cushion convex portion 142) to bend until its height reaches the tip of the electrode portion (electrode convex portion 123) is 3 kPa or more and 30 kPa or less. 10. A support 110 attached to the head 20; The electrode unit 190 according to 1. or 2. attached to the support 110; The electroencephalogram measuring device 10 has the above-mentioned configuration. [Explanation of symbols]

[0091] 10. Electroencephalogram (EEG) measuring device 20 heads 22 scalp 110 Support 111 Base 112 Covering material 114 Support through hole 120 EEG electrode components 121 Electrode through hole 122 Base 123 Electrode convex part 124 Conductive materials 125 Electrode body 126 Convex forming surface 127 Wiring 129 Cover 130 Support elastic member 131 Elastic member recess 135 Elastic material through hole 140 Cushion part 142 Cushion protrusion 143 Slope 151 tube 152 Injection member 153 Connecting member 160 Signal Processing Unit 161 Reference potential measurement wiring 162 Circuit (Active Electrode) 163,165 Wiring 164 Conductive part 170 Belt 190 Electrode Unit

Claims

1. A base and an electrode portion protruding from one surface of the base portion; a plurality of elastic members provided around the electrode portion and not functioning as the electrode portion; and An electrode unit for measuring electroencephalograms, wherein the elastic member is higher than the electrode portion with respect to the one surface of the base portion.

2. The electrode unit according to claim 1 , wherein the elastic member is non-conductive.

3. The electrode unit according to claim 1 or 2, wherein the elastic member bends in a direction away from the electrode unit when the electrode unit is pressed against the head.

4. The electrode unit according to claim 3 , wherein the side surface of the elastic member facing the electrode portion has a slope that faces in a direction away from the electrode unit as the side surface becomes farther away from the base portion.

5. The elastic member has a truncated cone shape, The electrode unit according to claim 4 , wherein the truncated surface of the pyramid is the inclined surface.

6. The electrode unit according to claim 1 , wherein the electrode portion and the elastic member are provided as separate bodies.

7. The electrode unit according to claim 1 , wherein the electrode portion and the elastic member are integrally formed.

8. The electrode unit according to claim 1 , wherein the elastic member is made of a resin.

9. 3. The electrode unit according to claim 1, wherein the pressure required for bending the elastic member to reach the tip of the electrode portion is 3 kPa or more and 30 kPa or less.

10. A support attached to the head; The electrode unit according to claim 1 or 2 attached to the support; An electroencephalogram measuring device having:

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