Electroencephalogram (EEG) measuring device

Abstract

An electroencephalogram (EEG) measuring device (10) is provided, which includes a support (110) divided into multiple pieces that is attached to the head, an electrode unit (EEG electrode member (120)) held by the support (110), a buffer material (500) provided in the gaps between adjacent pieces, and a connecting part (400) that determines the relative position of adjacent pieces.

Description

Technical Field

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

Background Art

[0002] In electroencephalogram measurement, electrical measurement is performed by bringing electrodes into contact with the head.

[0003] Patent Document 1 describes performing electroencephalogram measurement by bringing the tip of an electrode pin supported by an elastic member into contact with the scalp.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in an electroencephalogram measuring device, when the support for supporting the electroencephalogram electrode member is in a net type or arm type, it is difficult to keep it attached in a state where a force acts on the electroencephalogram measuring device when the subject is in a sleeping position, such as at bedtime.

[0006] An object of the present invention is to provide a technique capable of performing electroencephalogram measurement while being attached even in a state where a force acts on the electroencephalogram measuring device when the subject is in a sleeping position or the like.

Means for Solving the Problems

[0007] According to the present invention, the following technique is provided. 1. A support body that is mounted on the head and is divided into a plurality of pieces, an electrode unit held by the support body, a buffer material provided in a gap between adjacent pieces, a connecting portion that determines the relative positions of adjacent pieces, An electroencephalogram (EEG) measuring device. 2. The electroencephalogram measuring device according to 1, wherein the connecting portion is a hook-and-loop fastener provided on the outer surface of the support. 3. An electroencephalogram measuring device according to 1. or 2., wherein the deformation of the cushioning material when a compressive load of 10N is applied, as measured by the method described below, is 0.5 mm or more and 9.5 mm or less. (method) A test specimen of the aforementioned cushioning material (dimensions: 50 mm long x 50 mm wide x 10 mm high) and a push-pull gauge with a 20 mm diameter disc-shaped pressure piece attached are set on a measuring stand equipped with a displacement gauge. The test specimen is compressed by the pressure piece, and the state is maintained for 20 seconds each time the position of the pressure piece is lowered by 0.2 mm. After maintaining the state for 20 seconds, the compression load (N) is read, and the change in the position of the pressure piece (mm) is plotted on the x-axis and the compression load (N) is plotted on the y-axis. This process is repeated to create an SS curve. From the obtained SS curve, the change in the position of the pressure piece when the compression load is 10 N is read and taken as the deformation amount when a compression load of 10 N is applied. 4. An electroencephalogram measuring device according to any one of 1 to 3, wherein the plurality of pieces include a central piece facing the top of the head, a right piece to the right of the central piece, and a left piece to the left of the central piece. 5. The electroencephalogram measuring device described in 4, wherein the right piece and the left piece each face at least the temporal region. 6. The dividing line (A) separating the central piece and the right piece passes between Fp2 and F8, Fz and F4, Cz and C4, and T6 and T4 in the international 10-20 electrode arrangement. The dividing line (B) separating the central piece and the left piece passes between Fp1 and F7, Fz and F3, Cz and C3, and T5 and T3 in the international 10-20 electrode arrangement. 4. or 5. An electroencephalogram (EEG) measuring device as described in 4. or 5. 7. The central piece comprises a first central piece on the frontal side and a second central piece on the occipital side. The dividing line (C) that divides the first central piece and the second central piece passes between Fp1 and Fz, and between Fp2 and Fz in the international 10-20 electrode placement method. The electroencephalogram measuring device according to any one of 4. to 6.

Advantages of the Invention

[0008] According to the present invention, it is possible to provide a technique that enables electroencephalogram measurement while being worn even when a force acts on the electroencephalogram measuring device with the subject in a sleeping position or the like.

Brief Description of the Drawings

[0009] [Figure 1] It is a figure which illustrates the partial cross section of the electroencephalogram measuring device which concerns on embodiment. [Figure 2] It is a perspective view which illustrates the electroencephalogram measuring device which concerns on embodiment. [Figure 3] It is a figure which illustrates the state which attached the support body which concerns on embodiment to the human head. [Figure 4] It is a figure which illustrates the state inside the support body which concerns on embodiment. [Figure 5] It is sectional drawing which shows the electroencephalogram electrode member of the state which the electroencephalogram measuring device which concerns on embodiment was attached to the head. [Figure 6] It is sectional drawing of the electroencephalogram electrode member which concerns on embodiment. [Figure 7] It is a figure explaining the position of the piece of the support body divided into four parts which concerns on embodiment and the electroencephalogram electrode member by the international 10-20 electrode placement method. [Figure 8] It is a perspective view which focused on the left side surface of the support body divided into four parts which concerns on embodiment. [Figure 9] It is a perspective view which focused on the right side surface of the support body divided into four parts which concerns on embodiment. [Figure 10] It is a front view which shows the support body divided into four parts which concerns on embodiment, the connection part which connects pieces, and the buffer material provided between pieces. [Figure 11] It is a figure which shows the compression SS curve of the buffer material provided between the pieces of the support body divided into four parts which concerns on embodiment.

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, similar components are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. In this specification, as shown in FIG. 3, when the subject wears the electroencephalogram measuring device of the present embodiment on the head, the right side as viewed from the subject is defined as the right, and the left side as viewed from the subject is defined as the left. First, an electroencephalogram measuring device in a basic form in which electroencephalogram electrodes are attached to a helmet-shaped support will be described. Subsequently, a configuration in which the helmet-shaped support is divided into a plurality of pieces and is exemplified by a four-divided configuration.

[0011] The electroencephalogram measuring device of the present embodiment includes a support divided into a plurality of pieces and worn on the head, an electrode unit held by the support, a buffer material provided in a gap between adjacent pieces, and a connecting portion that determines the relative positions of adjacent pieces. In the present embodiment, the electrode unit is also referred to as an electroencephalogram electrode member.

[0012] <Basic Form of Electroencephalogram Measuring Device> <Overview> FIG. 1 is a diagram illustrating a partial cross section of an electroencephalogram measuring device 10 according to an embodiment. FIGS. 2 to 4 are diagrams showing an overall view of the electroencephalogram measuring device 10. FIG. 2 is a perspective view of the electroencephalogram measuring device 10 as viewed from above. FIG. 3 is a view of the electroencephalogram measuring device 10 worn on the head 20 as viewed from the front. FIG. 4 is a diagram illustrating the state inside the support 110 (the side where the head 20 is inserted) of the electroencephalogram measuring device 10.

[0013] The electroencephalogram measuring device 10 includes a support 110, a support elastic member 130, a holding portion 180, and an electroencephalogram electrode member 120. By bringing the electroencephalogram electrode member 120 of the electroencephalogram measuring device 10 into contact with the head 20 (scalp 22), an electroencephalogram is measured. The electroencephalogram electrode member 120 is attached to the support elastic member 130 via the holding portion 180 and is held by the support 110.

[0014] As will be described in detail later, the support 110 is, for example, a helmet-type device worn on the head 20, and has a support through-hole 114 that penetrates the inside and outside, and a support elastic member 130 embedded in the support through-hole 114. The electroencephalogram electrode member 120 is held on the bottom surface 132 of the support elastic member 130 via a holding part 180. Also, in the examples in Figures 2 to 4, the support 110 is depicted as a single unit for convenience, but as will be described later using other figures, the support 110 is divided into multiple pieces.

[0015] The support elastic member 130 is provided with an elastic member recess 131 that extends from the surface to the bottom. The elastic member recess 131 communicates with the support through hole 114. By inserting a finger or the like into the elastic member recess 131 through the support through hole 114, the support elastic member 130 can be manipulated, or the holding part 180 attached to the support elastic member 130 can be manipulated to adjust the orientation of the electroencephalogram electrode member 120, etc.

[0016] In the examples shown in Figures 2 to 4, the support 110 is helmet-shaped. When the support 110 is helmet-shaped, it has a recess into which the head 20 is inserted. The electroencephalogram (EEG) measuring device 10 is configured such that one or more EEG electrode members 120 are in 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 also include a belt 170 for fixing the support 110 to the head 20, as shown in Figures 3 and 4.

[0017] Hereinafter, the side of the support 110 that faces 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 Figure 1, the direction from the inside to the outside of the support 110 is defined as the z direction. The x, y, and z directions are orthogonal to each other. The z direction is approximately the normal direction to the scalp 22. Note that the x, y, and z directions may be defined as different directions for each electroencephalogram electrode member 120 in the electroencephalogram measurement device 10.

[0018] In the examples shown in Figures 2 to 4, the support 110 holds multiple electroencephalogram (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, electroencephalograms are measured by the multiple 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 the positions F3, F4, C3, C4, P3, Pz, and P4 in the International 10-20 Electrode Placement Method. Hereafter, the electrode positions in the International 10-20 Electrode Placement Method will be conveniently referred to as "electrode positions," for example, F3 in the International 10-20 Electrode Placement Method will also be referred to as "electrode position F3." The number and positions of the EEG electrode members 120 provided on the support 110 are not particularly limited and can be set according to the application, etc. The electroencephalograms measured by each EEG electrode member 120 are transmitted to the signal processing unit 160.

[0019] In the example shown in Figure 1, the electroencephalogram measuring device 10 further comprises a support elastic member 130 and a holding part 180. The support elastic member 130 is elastically deformable. The support elastic member 130 has a recess (elastic member recess 131) that is indented from the outside to the inside. In this embodiment, at least a portion of the bottom surface of the elastic member recess 131 has a second through-hole (hereinafter also referred to as "elastic material through-hole 135") that penetrates the support elastic member 130. In this embodiment, a configuration in which substantially the entire bottom surface of the elastic member recess 131 is the elastic material through-hole 135 is illustrated. Hereafter, unless otherwise specified, the elastic member recess 131 and the elastic material through-hole 135 will be described as the same thing.

[0020] The shape of the support 110 is determined, for example, based on the average head shape. However, head shapes vary greatly from person to person, and an element is needed to absorb these differences. In the electroencephalogram (EEG) measuring device 10, in which the EEG electrode member 120 is held on the support 110 via the support elastic member 130, the support elastic member 130 elastically deforms when the support 110 is attached to the head 20. As the support elastic member 130 elastically deforms, even if there are individual differences in head shape (unevenness and surface angles), the EEG electrode member 120 can be stably brought into contact with the scalp and EEG measurements can be performed. Furthermore, a structure that divides the helmet-shaped support 110 into multiple pieces to better accommodate individual differences in head shape (such as unevenness and surface angles) will be described later in Figures 7 to 11.

[0021] Furthermore, as described above, fingers or the like are 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 part 180. Since no structure protruding from the inside to the outside of the support 110 is required for adjusting the orientation of the electroencephalogram electrode member 120, the center of gravity can be stabilized when the device is attached to the head 20. In addition, the person being measured can assume a sleeping position while wearing the support 110, thus reducing noise caused by body movements. Moreover, electroencephalogram measurements may be performed while the person being measured is moving around.

[0022] Furthermore, the electroencephalogram (EEG) electrode members 120 are detachable from the support 110. This allows for the replacement of the EEG electrode members 120 as needed, or the use of different types of EEG electrode members 120 for each measurement. Each component of the electroencephalogram (EEG) measuring device 10 is described in detail below.

[0023] <Details of each component of the electroencephalogram (EEG) measurement device> Figure 5 is a cross-sectional view showing the electroencephalogram (EEG) electrode member 120 before the EEG measurement device 10 is attached to the head, and corresponds to Figure 1. The explanation will mainly refer to Figures 1 and 5.

[0024] <Support> The support 110 has a shape that can cover at least a portion of the head 20. The support 110 only needs to be attachable to the head 20 and may be made of, for example, cloth or rubber. The support 110 may be, for example, helmet-shaped, hat-shaped, or band-shaped. In this embodiment, the support 110 comprises 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 when the support 110 is attached to the head 20.

[0025] The base body 111 is made of, for example, expanded polystyrene, rigid expanded polyurethane, expanded polyethylene, expanded polypropylene, etc. The base body 111 is provided with a plurality (seven in this case) of holes 115 that penetrate vertically at positions corresponding to the electrode positions F3, F4, C3, C4, P3, Pz, and P4 mentioned above. The support elastic member 130 is housed in the holes 115. The covering member 112 is made of, for example, resin. The covering member 112 is harder than the base body 111 and can protect the head 20. However, the support body 110 does not necessarily have to be equipped with the covering member 112.

[0026] <Support elastic material> The support elastic member 130 is housed in a hole 115 provided in the base 111 of the support 110. The external shape and size of the support elastic member 130 substantially match the internal 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 portion of the hole 115 provided in the support body 110, excluding the elastic member recess 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.

[0028] As shown in Figure 5, it is preferable that the diameter d2 of the support through-hole 114 is 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 manipulate the holding part 180. As a result, it becomes easier to adjust the orientation of the electroencephalogram electrode member 120, etc.

[0029] The support elastic member 130 is made of an elastic material. The elastic material consists of one or more selected from, for example, urethane sponge, polyethylene sponge, polypropylene sponge, and silicone rubber sponge. The elastic material may be a foam, and examples of foams include low-rebound sponge and low-rebound elastic foam.

[0030] The support elastic member 130 can be configured without a spring. When a spring is used, the spring's repulsive force increases in proportion to the amount of spring deformation. Therefore, when the amount of deformation is large, excessive repulsive force is generated, making it easy for the person being measured to feel pain. On the other hand, when using a foam elastic material, there is a displacement range in which the repulsive force does not increase much (is not proportional) with increasing deformation. By configuring the support elastic member 130 to be usable within such a displacement range, an appropriate repulsive force can be obtained even if the amount of deformation varies depending on the position of the electroencephalogram electrode member 120.

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

[0032] The thickness t of the support elastic member 130 is, for example, 10 mm to 100 mm 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 the direction perpendicular to the bottom surface 132 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 according to the force it receives in the thickness direction. Specifically, the support elastic member 130 is fixed to the support 110 on the surface opposite to the bottom surface 132 (top surface 133). The thickness t of the support elastic member 130 is preferably 20 mm to 60 mm 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 making the thickness t such that it can be appropriately compressed according to the shape of the head 20, the electroencephalogram electrode member 120 can be properly pressed 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 that faces the head is, for example, 3 cm². 2 More than 25cm 2 The following applies. The lower limit is preferably 5 cm. 2 That is all, more preferably 7cm 2 This concludes the explanation. This ensures an appropriate size for the electroencephalogram electrode member 120 and enables a stable posture (orientation). The upper limit is preferably 20 cm. 2 The following, more preferably 15 cm 2 The following applies. This prevents the orientation of the electroencephalogram electrode member 120 from moving too much, making adjustment difficult. The shape of the base is not particularly limited. Examples of base shapes include circular, square, egg-shaped, and elliptical. A circular shape is preferable from the viewpoint of making it easier to rotate the electroencephalogram electrode member 120. On the other hand, if it is not desirable to rotate the electroencephalogram electrode member 120, a shape other than circular is preferable.

[0034] <Holding part> The holding portion 180 is provided on the bottom surface 132 of the support elastic member 130. The holding portion 180 also holds the electroencephalogram electrode member 120 on the side opposite to the support elastic member 130 (bottom surface 183). In other words, the electroencephalogram electrode member 120 is attached to the support elastic member 130 via the holding portion 180. The holding portion 180 may be detachable from the support elastic member 130.

[0035] The retaining portion 180 integrally comprises a base portion 181 and a protrusion portion 182. The retaining portion 180 is made of, for example, hard plastic, and the base portion 181 and the protrusion portion 182 are molded simultaneously.

[0036] The base portion 181 is a substantially disc-shaped (flange-shaped) structure of a predetermined thickness. The base portion 181 has a conductive portion 164 and a circuit 162. Specifically, the bottom surface 183 of the base portion 181 has a first housing portion 185 recessed to accommodate the conductive portion 164 and a second housing portion 186 recessed to accommodate the circuit 162. The first housing portion 185 is located at the center of the disc shape. The position of the second housing portion 186 is not particularly limited, but it is positioned so that the housed circuit 162 functions properly. The function of the 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 disc shape). The protrusion 182 is fitted into the elastic member recess 131 (elastic member through hole 135) of the support elastic member 130 from the bottom side of the elastic member recess 131.

[0038] <Circuit> Circuit 162 includes, for example, a preamplifier that amplifies the electrical signal from the electroencephalogram electrode member 120. Circuit 162 is electrically connected to a conductive part 164 by wiring 163 and acquires electroencephalogram signals from the electroencephalogram electrode member 120 via the conductive part 164. Circuit 162 performs amplification processing according to predetermined settings and transmits the signal to a signal processing unit 160 via wiring 165.

[0039] <Electroencephalogram electrode components> Figure 6 is a cross-sectional view of the electroencephalogram electrode member 120. The electroencephalogram electrode member 120 comprises 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 that protrudes from the lower surface of the base 122 (hereinafter also referred to as the "protrusion-forming surface 126"). The conductive member 124 is attached to the upper surface 128 of the base 122.

[0040] <Conductive material> 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.

[0041] The first part 124a is columnar (cylindrical). Screw grooves are provided on the outside of the first part 124a. The second part 124b is, for example, disc-shaped. The first part 124a is screw-fitted to the conductive part 164 of the holding part 180.

[0042] <Electrode body> The electrode body 125 comprises a cylindrical base 122 and one or more electrode protrusions 123 provided on the base 122.

[0043] The electrode projection 123 has a first portion 123a, a conductive portion 123b, and a second portion 123c. Multiple electrode projections 123 are provided on the side of the base portion 122 opposite to the conductive member 124 side.

[0044] 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 pyramidal shape. The conductive portion 123b is provided so as to cover the first portion 123a. The tip of the first portion 123a is covered by 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 of the first portion 123a.

[0045] When the electroencephalogram electrode member 120 is pressed against the head 20 for electroencephalogram measurement, the second portion 123c comes into contact with the head 20. At this time, the electrolytic substances (generally salts) from the scalp 22 are absorbed into the second portion 123c. As a result, the electroencephalogram electrode member 120 and the scalp 22 become electrically conductive. The shape of the second portion 123c is not limited to a sphere. Furthermore, the gel-like material constituting the second portion 123c is not particularly limited as long as it can contain sufficient water and achieve sufficient strength and flexibility when pressed against the head 20, but for example, acrylic hydrogels or silicone hydrogels can be used.

[0046] The materials of the base 122 and the first part 123a will now be described. The base 122 and the first part 123a are composed of a rubber-like elastic body. Specifically, the rubber-like elastic body is rubber or thermoplastic elastomer (also simply called "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).

[0047] The conductive portion 123b is formed, for example, using a paste containing a highly conductive metal. The conductive portion 123b includes, for example, one or more selected from the group consisting of copper, silver, gold, nickel, tin, lead, zinc, bismuth, antimony, or alloys thereof.

[0048] Inside the first part 123a, a wiring 127 is provided that connects to the conductive part 123b. The wiring 127 electrically connects the conductive part 123b and the conductive member 124. The wiring 127 may be made of, for example, conductive fibers. As conductive fibers, one or more selected from the group consisting of metal fibers, metal-coated fibers, carbon fibers, conductive polymer fibers, conductive polymer-coated fibers, and conductive paste-coated fibers can be used. These may be used individually or in combination of two or more types.

[0049] The electroencephalogram electrode member 120 is attached to the conductive portion 164 of the holding portion 180 by screwing the first portion 124a of the conductive member 124 into the conductive portion 164 of the holding portion 180. In this way, the electroencephalogram electrode member 120 is attached to the support elastic member 130.

[0050] <Electrical connection relationships in electroencephalography (EEG) devices> The electrical connections in the electroencephalogram (EEG) measuring device 10 are described below. The EEG measuring device 10 further includes wiring 163, 165, circuit 162, signal processing unit 160, and reference potential measurement wiring 161 (see Figure 4). Of these, the conductive part 164, wiring 165, and circuit 162 are provided for each EEG electrode member 120. Wiring 163 and circuit 162 are fixed to the holding unit 180 together with the conductive part 164.

[0051] When the scalp 22 comes into contact with the second part 123c, electrical signals from the scalp 22 are transmitted to the conductive member 124 via the second part 123c, the conductive part 123b, and the wiring 127. In this way, the electrical signals obtained by each electroencephalogram electrode member 120 are sent from the conductive member 124 of the electroencephalogram electrode member 120 to the signal processing unit 160 via the conductive part 164, the wiring 163, the circuit 162, and the wiring 165.

[0052] The signal processing unit 160 is connected to the circuit 162 of the electroencephalogram (EEG) electrode member 120 (holding unit 180), and acquires data measured by the EEG electrode member 120 via the circuit 162. The signal processing unit 160 performs processing 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 through these processes into a recording unit provided within the signal processing unit 160. Furthermore, the signal processing unit 160 can transmit the EEG signal data to an external device via wired or wireless communication.

[0053] 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 for power supply. Consequently, the person being measured can move and act with a certain degree of freedom during the measurement. It also prevents noise that depends on the frequency of the power supply. The reference potential measurement wiring 161 connects the signal processing unit 160 and the reference electrode (not shown) to each other. The reference electrode is an electrode used to acquire a reference potential that serves as a standard in the measurement of electroencephalogram signals. The reference electrode is attached, for example, to the earlobe or the upper part of the outer ear with a clip, or attached to the bone on the back of the outer ear to acquire the reference potential.

[0054] <How to use an electroencephalogram (EEG) device> The method of using the electroencephalogram (EEG) measuring device 10 with the above configuration will be described below. First, as shown in Figure 3, the support body 110 with the EEG electrode members 120 attached is placed on the head 20. The EEG electrode members 120 are provided on the bottom surface 132 side of the support elastic member 130 via a holding portion 180.

[0055] At this time, the support elastic member 130 shrinks in the thickness direction according to the state of the head 20, and the electroencephalogram electrode member 120 is pressed against the scalp 22. In other words, the support elastic member 130 deforms according to the position and angle of the scalp 22 relative to the support 110. Also, the electroencephalogram electrode member 120 is pressed against the scalp 22 with a force corresponding to 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 electroencephalogram electrode member 120 relative to the support 110 changes to conform to the shape of the head 20.

[0056] If there is any discomfort in the contact between the electroencephalogram electrode member 120 and the scalp 22, a finger or the like can be inserted through the support through hole 114 to manipulate the elastic material through hole 135 or the holding part 180 of the support elastic member 130 to adjust the orientation of the electroencephalogram electrode member 120. By doing so, the hair on the scalp 22 can be parted, improving the contact between the electroencephalogram electrode member 120 and the scalp 22.

[0057] <Split-type support> Referring to Figures 7 to 11, an example of an electroencephalogram (EEG) measuring device 10 in which the support 110 is divided into multiple pieces is shown. Below, an example in which the support is divided into four pieces (division configuration) is described, but the number of pieces and the method of division are not limited to this example, and various configurations can be applied.

[0058] (Method of dividing the support) Referring to Figures 7-11, an example in which the support 110 is divided into four pieces will be explained. Figure 7 is a diagram illustrating the positions of the divided pieces of the support 110 and the electroencephalogram electrode members 120 according to the international 10-20 electrode placement method. Figure 8 is a three-dimensional view focusing on the left side of the support 110. Figure 9 is a three-dimensional view focusing on the right side of the support 110. Figure 10 is a front view showing the support 110, the connecting parts 400 that connect the pieces together, and the cushioning material 500 provided between the pieces.

[0059] The support 110 is divided into multiple pieces. Each piece has a base 111 and a covering member 112 as described in the basic form. Each piece is also provided with multiple through holes corresponding to the holes 115 in the basic form, and the electroencephalogram electrode member 120 is attached via the support elastic member 130 and the holding part 180. Furthermore, as shown in Figure 10, the support 110 has a buffer material 500 (for example, an elastic member) provided in the gap between adjacent pieces, and a connecting part 400 (for example, a hook-and-loop fastener, etc.) that determines the relative position of adjacent pieces. The electroencephalogram (EEG) measuring device 10 will now be described, focusing on the support body 110, which is divided into multiple pieces. The configuration of the EEG electrode members 120 and the structure for attaching the EEG electrode members 120 to the support body 110 are the same as in the basic form, and explanations of similar configurations will be omitted.

[0060] The piece comprises multiple components, including a central piece 300 facing the top of the head, a right piece 340 to the right of the central piece 300, and a left piece 330 to the left of the central piece 300. In this specification, the term "top of the head" refers to the position of the top of the head on the subject's head 20 when the subject is fitted with the electroencephalogram measuring device 10 of this embodiment on the subject's head 20, as shown in Figure 3.

[0061] The right piece 340 and the left piece 330 each face at least the temporal region. In other words, when the support 110 is attached to the head 20, the right piece 340 is positioned to cover the right side of the head, and the left piece 330 is positioned to cover the left side of the head. In this specification, the term "temporal region" refers to the position of the temporal region on the subject's head when the electroencephalogram measuring device 10 of this embodiment is attached to the subject's head 20 as shown in Figure 3. The term "right temporal region" refers to the position of the right temporal region as viewed from the subject, and the term "left temporal region" refers to the position of the left temporal region as viewed from the subject.

[0062] (Right hand gesture) A dividing line (A) 301 separating the central piece 300 (first central piece 310, second central piece 320) from the right piece 340 passes between electrode positions Fp2 and F8, Fz and F4, Cz and C4, and T6 and T4. The right piece 340 covers electrode positions F4, F8, C4, and T4. Here, the right piece 340 is provided with holes 341, 343, 342, and 344 at positions corresponding to electrode positions F4, F8, C4, and T4, respectively. Each of the holes 341, 342, 343, and 344 accommodates the support elastic member 130 described in the basic embodiment, and the electroencephalogram electrode member 120 is attached via the holding portion 180.

[0063] (Left peace sign) The dividing line (B) 302 separating the central piece 300 (first central piece 310, second central piece 320) from the left piece 330 passes between electrode positions Fp1 and F7, Fz and F3, Cz and C3, and T5 and T3. The left piece 330 covers electrode positions F3, F7, C3, and T3. Here, the left piece 330 is provided with holes 331, 333, 332, and 334 at positions corresponding to electrode positions F3, F7, C3, and T3, respectively. Each of the holes 331, 332, 333, and 334 accommodates the support elastic member 130 described in the basic embodiment, and the electroencephalogram electrode member 120 is attached via the holding portion 180.

[0064] (Center piece) The central piece 300 has a first central piece 310 on the frontal side and a second central piece 320 on the occipital side. The dividing line (C) 303 that separates the first central piece 310 and the second central piece 320 passes between electrode positions Fp1 and Fz, and Fp2 and Fz. The central piece 300 is provided with recessed housing sections 391 and 392 located near the top of the head, for example, as shown in Figure 10, to accommodate the signal processing units 160a and 160b side by side. In this specification, the frontal region refers to the position of the frontal region on the subject's head 20 when the subject is fitted with the electroencephalogram measuring device 10 of this embodiment, as shown in Figure 3, and the frontal side refers to the position on the subject's head that is close to the frontal region. In this specification, the occipital region refers to the position of the occipital region on the subject's head 20 when the subject is fitted with the electroencephalogram measuring device 10 of this embodiment, as shown in Figure 3, and the occipital side refers to the position on the subject's head that is close to the occipital region.

[0065] The first central piece 310 covers electrode positions Fp1 and Fp2. In this case, the electroencephalogram (EEG) electrode member 120 is not attached to the first central piece 310, and therefore no holes for attaching the EEG electrode member 120 are provided. However, if the device measures EEG at electrode positions Fp1 and Fp2, holes for attaching the EEG electrode member 120 may be provided at electrode positions Fp1 and Fp2.

[0066] The second central piece 320 covers the electrode positions Fz, Cz, Pz, P3, P4, T5, T6, O1, and O2. The second central piece 320 is provided with holes 321, 322, 323, 324, 325, 326, 327, 328, and 329 at positions corresponding to the electrode positions Fz, Cz, T5, P3, Pz, P4, T6, O1, and O2, respectively. Each of the holes 321, 322, 323, 324, 325, 326, 327, 328, and 329 accommodates the support elastic member 130 described in the basic embodiment, and the electroencephalogram electrode member 120 is attached via the holding portion 180.

[0067] (Connection part) Each piece of the divided support 110 (first central piece 310, second central piece 320, left piece 330, right piece 340) is connected by a connecting portion 400. Here, "connected" refers to a state in which the relative positions can be adjusted within a predetermined range and the pieces are connected to each other. The connecting portion 400 preferably has a structure that connects the pieces and allows for easy change of the connection position and clearance between pieces. For example, hook-and-loop fasteners, belts, rubber bands, buckles, etc., can be suitably used, and hook-and-loop fasteners are preferred from the viewpoint of making it easier to adjust the relative positions of the pieces. Furthermore, from the viewpoint of further improving the fit with the head 20, it is preferable to employ a connecting part 400 with a structure that allows the piece to move in the direction of contraction of the cushioning material 500 (described later) while suppressing the movement of the piece in the direction of stretching (loosening) of the cushioning material 500. Also, all connecting parts 400 used may be of the same type, or different types may be used. Here, we will describe an example in which a hook-and-loop fastener is provided on the outer surface of the support 110 as the connecting portion 400.

[0068] A hook-and-loop fastener, for example, connects or separates by the hook-and-loop fastener (A) having a hook-shaped (J-hook) surface A and a hook-and-loop fastener (B) having a surface B with densely packed loops, which hook or detach from each other. In this embodiment, the hook-and-loop fastener (A) is fixed to the support 110 side, and the hook-and-loop fastener (B) of the adjacent piece is attached from above to the hook-and-loop fastener (A) of the adjacent piece to connect them.

[0069] (Connection between the first central piece, the left piece, and the right piece) Specifically, in the example shown in Figure 10, a rectangular face fastener (A) 401 is provided in the lower region of the surface of the first central piece 310, with the width direction (left-right direction in Figure 10) as the longitudinal direction.

[0070] On the surface of the left piece 330, a rectangular hook-and-loop fastener (A) 402 is provided below the hole 331 corresponding to the electrode position F3. The hook-and-loop fastener (A) 401 of the first central piece 310 and the hook-and-loop fastener (A) 402 of the left piece 330 are bonded to hook-and-loop fastener (B) 412. This connects the first central piece 310 and the left piece 330. By adjusting the bonding position between hook-and-loop fasteners (A) 401, 402 and hook-and-loop fastener (B) 412, the gap between the first central piece 310 and the left piece 330 can be adjusted.

[0071] On the surface of the right piece 340, a rectangular hook-and-loop fastener (A) 403 is provided below the hole 341 corresponding to electrode position F4. The hook-and-loop fastener (A) 401 of the first central piece 310 and the hook-and-loop fastener (A) 403 of the right piece 340 are bonded to hook-and-loop fastener (B) 413. This connects the first central piece 310 and the right piece 340. By adjusting the bonding position between hook-and-loop fasteners (A) 401, 403 and hook-and-loop fastener (B) 413, the gap between the first central piece 310 and the right piece 340 can be adjusted.

[0072] (Connection between the second central piece, the left piece, and the right piece) On the surface of the second central piece 320, a hook-and-loop fastener (A) 406 is provided between the hole 321 corresponding to the electrode position Fz and the dividing line (A) 301, and a hook-and-loop fastener (A) 407 is provided between the hole 321 corresponding to the electrode position Fz and the dividing line (B) 302.

[0073] A rectangular hook-and-loop fastener (A) 404 is provided on the surface of the left piece 330 near the hole 332 corresponding to electrode position C3. The hook-and-loop fastener (A) 406 of the second central piece 320 and the hook-and-loop fastener (A) 404 of the left piece 330 are bonded to hook-and-loop fastener (B) 414. This connects the second central piece 320 and the left piece 330. The gap between the second central piece 320 and the left piece 330 can be adjusted by adjusting the bonding position of hook-and-loop fasteners (A) 406, 404 and hook-and-loop fastener (B) 414. The second central piece 320 and the left piece 330 are also connected on the occipital side by hook-and-loop fasteners (A) and (B) (not shown).

[0074] A rectangular hook-and-loop fastener (A) 405 is provided on the surface of the right piece 340 near the hole 342 corresponding to electrode position C4. The hook-and-loop fastener (A) 407 of the second central piece 320 and the hook-and-loop fastener (A) 405 of the right piece 340 are bonded to hook-and-loop fastener (B) 415. This connects the second central piece 320 and the right piece 340. The gap between the second central piece 320 and the right piece 340 can be adjusted by adjusting the bonding position of hook-and-loop fasteners (A) 407, 405 and hook-and-loop fastener (B) 415. The second central piece 320 and the right piece 340 are also connected on the occipital side by hook-and-loop fasteners (A) and (B), which are not shown.

[0075] An example has been described in which a hook-and-loop fastener is used as the connecting portion 400 and is provided on the outer surface (hereinafter also referred to as the outer surface) of the support 110. However, the connecting portion 400 may also be provided on the inner surface (hereinafter also referred to as the inner surface) of the support 110, on the outer surface of the support 110, or between pieces (dividing line (A) 301, dividing line (B) 302, dividing line (C) 303). From the viewpoint of further suppressing noise caused by contact with the electroencephalogram electrode member 120 and from the viewpoint of making adjustment of the connecting portion easier, it is preferable to provide it on the outer surface (outer surface) of the support 110. Furthermore, as described above, it is preferable to use hook-and-loop fasteners from the viewpoint of easily adjusting the relative positions of the pieces. Therefore, the connecting portion 400 is preferably a hook-and-loop fastener provided on the outer surface of the support 110.

[0076] (buffer material) A buffer material 500 is provided between each piece of the divided support 110. By providing the buffer material 500, it is possible to prevent the pieces from coming into contact with each other. If the pieces come into contact, the vibrations caused by the contact may introduce noise into the brainwaves being detected, and by providing the buffer material 500, such noise can be prevented. Here, the buffer material 500 is provided in part of the gaps between the pieces (dividing line (A) 301, dividing line (B) 302, dividing line (C) 303).

[0077] In the example shown in Figure 10, the cushioning material 500 is attached to the connecting portion 400, for example, a hook-and-loop fastener, at the location between each piece where the connecting portion 400 is provided. In other words, the cushioning material 500 is detachably attached to the main body of the support 110 by being attached to the connecting portion 400. When adjacent pieces are brought close together by the connecting portion 400, the cushioning material 500 is sandwiched between these adjacent pieces. In the following description, unless distinguished, cushioning materials 501 to 504 will be collectively referred to as "cushioning material 500".

[0078] Specifically, in the portion where the hook fastener (A) 401 of the first central piece 310 and the hook fastener (A) 402 of the left piece 330 are connected by a hook fastener (B) 412, a buffer material 501 is provided between the first central piece 310 and the left piece 330.

[0079] In the portion where the hook fastener (A) 401 of the first central piece 310 and the hook fastener (A) 403 of the right piece 340 are connected by a hook fastener (B) 413, a buffer material 502 is provided between the first central piece 310 and the right piece 340.

[0080] In the portion where the hook fastener (A) 406 of the second central piece 320 and the hook fastener (A) 404 of the left piece 330 are connected by a hook fastener (B) 414, a buffer material 503 is provided between the second central piece 320 and the left piece 330.

[0081] In the portion where the hook fastener (A) 407 of the second central piece 320 and the hook fastener (A) 405 of the right piece 340 are connected by a hook fastener (B) 415, a buffer material 504 is provided between the second central piece 320 and the right piece 340.

[0082] Although not shown in the diagram, cushioning material 500 is also provided on the occipital side and in the parts connected by hook-and-loop fasteners. Depending on where the cushioning material 500 is used and the shape of the head 20 of the person wearing the electroencephalogram measuring device 10, a material of different size and hardness can be appropriately selected. Furthermore, it is not necessary to provide cushioning material 500 between all pieces. In addition, the cushioning material 500 may also function as a connecting part 400.

[0083] The shape of the cushioning material 500 is not particularly limited, but for example, it can be a rectangular parallelepiped. Its size can be, for example, 10mm to 40mm in length, 10mm to 40mm in width, and 1mm to 25mm in thickness. The lower limits of length and width are preferably 10mm or more, more preferably 20mm or more. The upper limits are preferably 35mm or less, more preferably 30mm or less. The lower limit of thickness is preferably 2mm or more, more preferably 5mm or more. The upper limit is preferably 20mm or less, more preferably 15mm or less. By setting the size of the cushioning material 500 within this range, the transmission of movement of one piece to other pieces can be suppressed. While cushioning material 500 may be provided throughout the entire space between each piece, it is preferable to provide it in three locations: the forehead, the crown, and the back of the head, from the viewpoint of suppressing the transmission of movement of the temporal region to the pieces.

[0084] As the material for the cushioning material 500, for example, an elastic material as exemplified in the support elastic member 130 can be used. The elastic material consists of one or more selected from, for example, urethane sponge, polyethylene sponge (foamed polyethylene), polypropylene sponge, and rubber sponge (foamed rubber).

[0085] The physical properties of the cushioning material 500 can be suitably defined, for example, by a compression SS curve. The deformation amount when a compressive load of 10N is applied, as measured by the method described below, is 0.5 mm or more and 9.5 mm or less. The lower limit of the deformation amount is preferably 1 mm or more, more preferably 2 mm or more. The upper limit is preferably 8 mm or less, more preferably 6 mm or less. The amount of deformation is preferably 1 mm to 8 mm, and more preferably 2 mm to 6 mm. By setting the range of physical properties in the compression SS curve of the cushioning material 500 to the above numerical range, the cushioning material 500 can appropriately absorb the force when a force is applied in the direction that brings each piece closer together. (method) A test specimen of the cushioning material 500 of this embodiment (dimensions: 50 mm long x 50 mm wide x 10 mm high) and a push-pull gauge (Nidec-Shimpo Corporation Digital Force Gauge FGJN-2) with a 20 mm diameter disc-shaped pressure piece attached are set on a measuring stand equipped with a displacement meter. The test specimen is compressed by the pressure piece, and the state is maintained for 20 seconds each time the position of the pressure piece is lowered by 0.2 mm. After maintaining the state for 20 seconds, the compression load (N) is read, and the change in the position of the pressure piece (mm) is plotted on the x-axis and the compression load (N) is plotted on the y-axis. This process is repeated to create an SS curve. From the obtained SS curve, the change in the position of the pressure piece when the compression load is 10 N is read and taken as the deformation amount when a compression load of 10 N is applied.

[0086] Figure 11 shows examples of compression SS curves for four types of cushioning materials used as cushioning material 500. The following four types of materials, A to D, are used in the cushioning material 500. A: Foamed polyethylene (1) Manufactured by TRUSCO, product name "TPES" B: Foamed polyethylene (2) Manufactured by Sakai Chemical Industry Co., Ltd., product name "Minafoam" C: Low-rebound urethane, manufactured by ITEC, product name "KTHU" D: Foamed rubber, manufactured by Hikari Co., Ltd., product name "KSEP" Materials A to D (and materials with similar properties) can be used as appropriate. Assuming a head load of approximately 40 N, it is preferable to use materials within the above range that exhibit relatively smaller changes rather than those that exhibit excessively large changes. In the example shown in Figure 11, material B (foamed polyethylene (2)) is the most preferred. Material C (low-rebound urethane) exhibits a large change, so while it can be used for small head loads, it is preferable to avoid using it for large head loads.

[0087] (Summary of the embodiments) The characteristics of the embodiment can be briefly summarized as follows: 1. A support body 110, which is divided into multiple pieces, is attached to the head 20, An electrode unit (EEG electrode member 120) is held by the support 110, A buffer material 500 is provided in the gap between adjacent pieces, A connecting portion 400 that determines the relative position of adjacent pieces, An electroencephalogram (EEG) measuring device 10 having the following features. Multiple pieces are connected, and the size can be adjusted by changing the distance between the pieces. The presence of cushioning material 500 between the pieces absorbs the load even when a load is applied to the temporal side of the support 110, such as when a subject undergoing electroencephalography changes their posture from lying on their back to lying on their side. As a result, changes in the contact position of the electroencephalogram electrode member 120 can be suppressed. Furthermore, the presence of the connecting section 400 makes it easier to adjust the distance between pieces. 2. The electroencephalogram measuring device 10 as described in 1, wherein the connecting portion 400 is a hook-and-loop fastener provided on the outer surface of the support 110. By using a hook-and-loop fastener provided on the outer surface of the support 110 as the connecting portion 400, the connection state can be easily adjusted. Furthermore, the hook-and-loop fastener can be made with a configuration that minimizes protrusions and indentations. 3. An electroencephalogram measuring device 10 as described in 1. or 2., wherein the deformation of the cushioning material 500 when a compressive load of 10N is applied, as measured by the method described below, is 0.5 mm or more and 9.5 mm or less. (method) A test specimen of the cushioning material 500 (dimensions: 50 mm long x 50 mm wide x 10 mm high) and a push-pull gauge with a 20 mm diameter disc-shaped pressure piece attached are set on a measuring stand equipped with a displacement gauge. The test specimen is compressed by the pressure piece, and the state is maintained for 20 seconds each time the position of the pressure piece is lowered by 0.2 mm. After maintaining the state for 20 seconds, the compression load (N) is read, and the change in the position of the pressure piece (mm) is plotted on the x-axis and the compression load (N) is plotted on the y-axis. This process is repeated to create an SS curve. From the obtained SS curve, the change in the position of the pressure piece when the compression load is 10 N is read and taken as the deformation when a compression load of 10 N is applied. By using a cushioning material 500 with these physical properties, the force acting on the support 110 can be appropriately absorbed even when electroencephalogram measurements are taken in a sleeping position, such as during sleep. 4. An electroencephalogram measuring device 10 according to 1. or 2., comprising, as a plurality of pieces, a central piece facing the top of the head (first implementation: first central piece 310, second central piece 320), a right piece to the right of the central piece (first central piece 310, second central piece 320) (right piece 340), and a left piece to the left of the central piece (first central piece 310, second central piece 320) (left piece 330). By dividing the support 110 in this way, changes in the positional relationship between the electroencephalogram electrode member 120 and the scalp 22 (clearance between the inside of the support 110 and the head 20) are suppressed in response to changes in the subject's posture during measurements, such as while sleeping. As a result, stable electroencephalogram measurements can be achieved. 5. The right piece 340 and the left piece 330 are each facing at least the temporal region, respectively, of the electroencephalogram measuring device 10 as described in 4. or 5. The divided pieces include a right piece 340 and a left piece 330, which helps to suppress changes in the positional relationship between the electroencephalogram electrode member 120 and the scalp 22, even when lying on one's side (lateral position) during sleep. 6. The dividing line (A) 301 separating the central piece 300 (first central piece 310, second central piece 320) from the right piece 340 passes between Fp2 and F8, Fz and F4, Cz and C4, and T6 and T4 in the international 10-20 electrode arrangement. The electroencephalogram measuring device 10 as described in 4. or 5., wherein the dividing line (B) 302 separating the central piece (first central piece 310, second central piece 320) and the left piece 330 passes between Fp1 and F7, Fz and F3, Cz and C3, and T5 and T3 in the international 10-20 electrode placement method. With this configuration, the movements of the first central piece 310 and the second central piece 320 become independent, and changes in the contact state between the electroencephalogram electrode member 120 and the scalp 22 can suppress the influence of one piece on the other. 7. The central piece comprises a first central piece 310 on the frontal side and a second central piece 320 on the occipital side. The dividing line (C) 303 separating the first central piece 310 and the second central piece 320 passes between Fp1 and Fz, and Fp2 and Fz, in the international 10-20 electrode placement method, in the electroencephalogram measuring device 10 as described in any of 4. to 6. This configuration allows the movement of the first central piece 310 and the second central piece 320 to be independent. As a result, changes in the contact state between the electroencephalogram electrode member 120 and the scalp 22 in one piece can be suppressed from affecting the other piece.

[0088] This application claims priority based on Japanese Patent Application No. 2024-106676, filed on 2 July 2024, and incorporates all of its disclosures herein. [Explanation of Symbols]

[0089] 10. Electroencephalogram (EEG) measuring device 20 heads 22 Scalp 110 Support 111 Base 112 Covering member 114 Support through hole 115 holes 120 Electroencephalogram (EEG) electrode components 122 Base 123 Electrode protrusion 123a Part 1 123b Conductive part 123c Part 2 124 Conductive material 124a Part 1 124b Part 2 125 Electrode body 126 Surface forming protrusion 127 Wiring 128 Top 129 Cover 130 Support elastic member 131 Elastic member recess 132 Base 133 Top surface 135 Elastic material through hole 160 Signal Processing Unit 160a Signal Processing Unit 160b Signal Processing Unit 161 Wiring for measuring reference potential 162 circuits 163 Wiring 164 Conductive part 165 Wiring 170 belt 180 Holding part 181 Base 182 Convex part 183 Base 184 Top surface 185 First Detention Unit 186 Second Detention Unit 300 central piece 301 Dividing line (A) 302 Parting line (B) 303 Parting line (C) 310 First central piece 320 Second central piece 321~329 hole 330 Left piece 331~334 hole 340 Right Piece 341~344 hole 400 Connection section 401-407 Folding fastener (A) 412-415 Folding fastener (B) 500 Cushioning material 501~504 Cushioning material

Claims

1. A support structure, divided into multiple pieces, that is attached to the head, An electrode unit held in the support, A buffer material is provided in the gap between adjacent pieces, A connecting portion that determines the relative position of adjacent pieces, An electroencephalogram (EEG) measuring device.

2. The electroencephalogram measuring device according to claim 1, wherein the connecting portion is a hook-and-loop fastener provided on the outer surface of the support.

3. The electroencephalogram measuring device according to claim 1 or 2, wherein the deformation of the cushioning material when a compressive load of 10 N is applied, as measured by the method described below, is 0.5 mm or more and 9.5 mm or less. (method) A test piece of the aforementioned cushioning material (dimensions: 50 mm long x 50 mm wide x 10 mm high) and a push-pull gauge with a 20 mm diameter disc-shaped pressure piece attached are set on a measuring stand equipped with a displacement sensor. The test specimen is compressed with the pressure piece, and the state is maintained for 20 seconds each time the position of the pressure piece is lowered by 0.2 mm. After maintaining the state for 20 seconds, the compression load (N) is read, and the change in the position of the pressure piece (mm) is plotted on the x-axis and the compression load (N) is plotted on the y-axis. This process is repeated to create an SS curve. From the obtained SS curve, the change in the position of the pressure piece when the compression load is 10 N is read and taken as the amount of deformation when a compression load of 10 N is applied.

4. The electroencephalogram measuring device according to claim 1 or 2, wherein the shape of the cushioning material is a rectangular parallelepiped.

5. The electroencephalogram measuring device according to claim 4, wherein the rectangular parallelepiped has a length of 10 mm or more and 40 mm or less, a width of 10 mm or more and 40 mm or less, and a thickness of 1 mm or more and 25 mm or less.

6. The electroencephalogram measuring device according to claim 1 or 2, wherein the cushioning material is an elastic material.

7. The electroencephalogram measuring device according to claim 6, wherein the elastic material comprises one or more selected from urethane sponge, polyethylene sponge, polypropylene sponge, and rubber sponge.

8. The electroencephalogram measuring device according to claim 1 or 2, wherein the plurality of pieces include a central piece facing the top of the head, a right piece to the right of the central piece, and a left piece to the left of the central piece.

9. The electroencephalogram measuring device according to claim 8, wherein the right piece and the left piece each face at least the temporal region.

10. The dividing line (A) separating the central piece and the right piece passes between Fp2 and F8, Fz and F4, Cz and C4, and T6 and T4 in the international 10-20 electrode arrangement method. The dividing line (B) separating the central piece and the left piece passes between Fp1 and F7, Fz and F3, Cz and C3, and T5 and T3 in the international 10-20 electrode arrangement method. The electroencephalogram measuring device according to claim 8.

11. The aforementioned central piece has a first central piece on the frontal side and a second central piece on the occipital side. The electroencephalogram measuring device according to claim 8, wherein the dividing line (C) separating the first central piece and the second central piece passes between Fp1 and Fz, and Fp2 and Fz in the international 10-20 electrode arrangement.

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