WO2024185805A1

WO2024185805A1 - Brain wave measuring device and pad for brain wave measuring device

Info

Publication number: WO2024185805A1
Application number: PCT/JP2024/008491
Authority: WO
Inventors: 貞雄政吉
Original assignee: ＦｒｏｎｔＡｃｔ株式会社
Priority date: 2023-03-06
Filing date: 2024-03-06
Publication date: 2024-09-12

Abstract

The purpose of the present invention is to provide a brain wave measuring device that is wearable and that, in order to improve the quality of the measured brain wave signals, has a structure that can achieve both an improvement in durability and an improvement in fit.　This brain wave measuring device can be worn on the head of a living body and comprises: an accommodation part that is curved and that comprises a front-side component and a rear-side component; a measurement electrode that is disposed on the front surface of the rear-side component; a signal processing unit that is accommodated in the accommodation part; and a pad that is disposed on the front surface of the rear-side component near the measurement electrode.

Description

Electroencephalogram measuring device and pad for electroencephalogram measuring device

The present invention relates to an electroencephalogram measuring device and a pad for an electroencephalogram measuring device.

　The devices described in Patent Document 1 (Non-Patent Document 1) and

Non-Patent Documents

2 and 3 are known as wearable electroencephalography devices (wearable electroencephalographs) that are worn on the head of a living body such as a human body to measure electroencephalograms. The electroencephalography device in Patent Document 1 (Non-Patent Document 1) has two electrodes on the forehead side and has a double band structure consisting of an outer band and an inner band, but the outer band and the inner band are each integrated parts (FIG. 16 of Patent Document 1), and the device in Patent Document 1 (Non-Patent Document 1) has problems with wearing comfort. The electroencephalography device in Non-Patent Document 2 is a hairband-type device with two electrodes on the forehead side, but since the device is a hairband-type device using a soft material, it has durability problems, and the device in Non-Patent Document 2 is thought to have a high risk of failure such as disconnection. The electroencephalography device in Non-Patent Document 3 has a structure in which many electrodes protrude from the main body, but because the device is attached to the living head so that it is positioned from the left temporal region along the back of the head and the right temporal region, there is a risk that the electrodes on the frontal side may not be adequately fixed, and because the device in Non-Patent Document 3 has many wires from many electrodes protruding from the main body, the device in Non-Patent Document 3 also has durability problems.

　Conventional wearable EEG monitors are mainly headband-type and made of soft materials, but these are less durable and suffer from frequent breakdowns such as broken wires. In contrast, when a wearable EEG monitor with a housing structure made of hard materials is used to increase durability, it is difficult to create an EEG monitor that fits the head of every person because head shapes vary from person to person. As a result, there are problems such as the subject (the person undergoing EEG measurement) feeling pain in the head when wearing the EEG monitor, or the quality of the signal being unstable due to factors such as the electrodes not making sufficient contact with the subject's head when worn, or the pain felt by the subject affecting the EEG.

U.S. Pat. No. 9,867,571

In view of the above, the present invention aims to provide a wearable EEG measuring device with an improved fit, which contributes to improving the quality of the measured EEG signals, and a pad for the EEG measuring device to achieve an improved fit.

In order to solve the above problems, the electroencephalogram measuring device of the present invention is characterized by having a housing part that includes at least a front part and a rear part, and has a curved shape that is positioned along the living head from the left temporal part to the forehead and right temporal part when attached to the head, a measurement electrode that is placed on the surface of the rear part and contacts the forehead when attached, a signal processing part that is contained within the housing part and processes the electrical signal obtained via the measurement electrode, and a pad that is placed on the surface of the rear part near the measurement electrode.

In the electroencephalogram measuring device according to the present invention, the pads can be made of elastomer, and the elastomer can have a hardness value of 70 to 94 according to Japanese Industrial Standard JIS K 6253 type A.

In the EEG measurement device of the present invention, the thickness of the pad can be in the range of 1 mm to 4 mm from the surface of the rear part. In the EEG measurement device of the present invention, the thickness of the pad can be in the range of -1 mm to +1 mm relative to the thickness of the measurement electrode from the surface of the rear part. In the EEG measurement device of the present invention, the thickness of the pad can be approximately 2 mm from the surface of the rear part, and approximately equal to the thickness of the measurement electrode from the surface of the rear part.

In the electroencephalogram measuring device according to the present invention, the number of measuring electrodes is at least two or more, a pad is located at the midpoint between two of the measuring electrodes, and the centers of the contact surfaces of the measuring electrodes that come into contact with the forehead when worn can be spaced apart from each other on the left and right by a distance in the range of 40 mm to 90 mm along the shape of the back part. In the electroencephalogram measuring device according to the present invention, the contour of the contact surface of the measuring electrodes that comes into contact with the forehead when worn can be a circle with a diameter in the range of 10 mm to 25 mm.

In the electroencephalogram measuring device according to the present invention, the storage section can be configured such that the distance between the ends expands when the storage section is attached to the head of a living subject, and the storage section can maintain the state of being attached to the head of a living subject by the restoring force from the expanded state.

The present invention can also be used as a pad for an electroencephalogram measuring device for an electroencephalogram measuring device having the above-mentioned characteristics.

The present invention provides an electroencephalogram measuring device that can be worn on the head of a living body, the device being configured to include a curved housing consisting of a front part and a rear part, measurement electrodes installed on the surface of the rear part, a signal processing unit housed within the housing, and pads installed on the surface of the rear part near the measurement electrodes and that come into contact with the forehead when worn to assist in maintaining the electroencephalogram measuring device attached to the head of a living body. By configuring the device so that the pads come into contact with the forehead when worn, the device assists in maintaining the electroencephalogram measuring device attached to the head of a living body, and allows the measurement electrodes to come into proper contact with the head, improving the fit for the user (subject) and improving the quality of the electroencephalogram signals that can be measured.

1 is a schematic diagram of an electroencephalogram measuring device according to one embodiment of the present invention (as viewed from diagonally below and in front of a user wearing the device). 1 is a schematic diagram of an electroencephalogram measuring device according to one embodiment of the present invention (as viewed from diagonally below and behind the user wearing the device). 1 is a schematic diagram of an electroencephalogram measuring device according to one embodiment of the present invention (viewed from above of a user wearing the device). 1 is a schematic diagram of an electroencephalogram measuring device according to one embodiment of the present invention (as viewed from below the user wearing it). 1 is an exploded view (perspective view) of the housing of an electroencephalogram measuring device according to one embodiment of the present invention, disassembled into its respective component parts. FIG. FIG. 2 is a schematic diagram of the front part of the electroencephalogram measuring device according to one embodiment of the present invention (as viewed from above of the user wearing it). 1 is a schematic diagram of the back side components of an electroencephalogram measuring device according to one embodiment of the present invention (as viewed from above of the user wearing it). FIG. 1 is a schematic diagram of a housing section of an electroencephalogram measuring device according to one embodiment of the present invention (as viewed from above of a user wearing the device). FIG. 1 is a schematic diagram of an electroencephalogram measuring device according to one embodiment of the present invention (as viewed from the right ear side of a user wearing the device). 1 is a schematic diagram of an electroencephalogram measuring device according to one embodiment of the present invention (as viewed from the left ear side of a user who wears it). 1 is a schematic diagram of an electroencephalogram measuring device according to one embodiment of the present invention (worn on a user's head). FIG. 4 is a schematic diagram of a mounting assistance band. FIG. 2 is a partially enlarged view of the vicinity of the measurement electrodes and pads of an electroencephalogram measuring device according to one embodiment of the present invention (a view of the front part of the electroencephalogram measuring device from above the user who is wearing it). FIG. 2 is a partially enlarged view of the vicinity of the measurement electrodes and pads of an electroencephalogram measuring device according to one embodiment of the present invention (a view of the front part of the electroencephalogram measuring device from diagonally below and behind the user wearing it). 2 is a cross-sectional view taken along line AA of an electroencephalogram measuring device according to one embodiment of the present invention. FIG. 1 is a block diagram showing a configuration of an electroencephalogram measuring apparatus according to one embodiment of the present invention; FIG. 2 is a block diagram showing a configuration of a data collection terminal device. 3 is a flowchart showing the operation of the electroencephalogram measuring device and the data collection terminal device according to one embodiment of the present invention.

Below, an exemplary embodiment of the present invention, the electroencephalogram measuring device 1, will be described with reference to the drawings. The electroencephalogram measuring device 1 according to the present invention is not limited to the specific aspects described below, and can be modified as appropriate within the scope of the technical idea of the present invention. Individual functions, elements, etc. included in the embodiments described below can be deleted or modified as appropriate within the scope of the present invention, and any functions, elements, etc. not included in the embodiments can be added within the scope of the present invention. For example, in the following embodiments, the storage section is described as being composed of a front side part and a back side part, and the front side part is further composed of three parts, a central front side part, a left front side part, and a right front side part, but the number of components of the storage section can be changed arbitrarily, such as to four or more (for example, the central front side part may be disassembled into two parts). In addition, the material of each component of the storage section is preferably an insulator, but at least a part of each component may be composed of a conductive material such as a metal, as long as problems such as short circuits between each electrode and circuit element do not occur. Each component may be made of any material, including silicon, rubber, plastic, and resin, may be made of any multiple materials, and each component may be disassembled into two or more components. Not limited to the components of the container, all components related to the electroencephalogram measuring device 1 may be made of any material and disassembled into any number of elements unless otherwise specified. In the following embodiment, the number of measurement electrodes is described as two, but the number of measurement electrodes can be changed to any number greater than one, such as one or three or more, and the positions of the measurement electrodes can also be changed within an appropriate range. The number of reference electrodes and ground electrodes (GND electrodes) can also be changed arbitrarily (at least one of them does not need to be provided as long as the electroencephalogram measuring device 1 operates). The wearing auxiliary band is not limited to the form shown in the embodiment, and any type of band can be used, and the electroencephalogram measuring device 1 can be implemented without using the wearing auxiliary band. The various functional units described below that perform signal processing and the like can be realized in any configuration, such as an ASIC (application specific integrated circuit), an embedded system, or a microcomputer, and digital information processing may be performed by providing the various functional units with a CPU (Central Processing Unit), a memory device, etc. Furthermore, the user in the following embodiments is typically an adult human of average build, but may be any living being, including humans, and the overall size of the electroencephalogram measuring device 1 and the size of each component can be changed within an appropriate range according to the size of the head of the subject to be measured.

1 to 4 are schematic diagrams of an electroencephalogram measuring device 1 according to an embodiment of the present invention, as viewed from a downward diagonal position in front of the user wearing it (FIG. 1), a downward diagonal position in the rear of the user wearing it (FIG. 2), above (FIG. 3), and below (FIG. 4). In the following, the position and direction will be expressed based on the state in which the electroencephalogram measuring device 1 is worn on the head (biological head) of a user in a standing position, typically with an average head width for an adult. The overall shape of the electroencephalogram measuring device 1 is determined by a housing section 1A that combines a rear part 5 with a front part 1B that is composed of a right front part 2, a central front part 3, and a left front part 4. In addition to the housing section 1A that is composed of the front part 1B and the rear part 5, the electroencephalogram measuring device 1 typically includes two

measurement electrodes

6 and 7, a signal processing section, and a pad 50.

FIG. 5 shows the state in which the storage unit 1A is disassembled into each component part. The storage unit 1A is formed by combining the right front part 2, the center front part 3, the left front part 4, and the back part 5. FIG. 6 shows the structure of the front part 1B seen from above. The right front part 2, the center front part 3, and the left front part 4 are combined to form the front part 1B. The front part 1B can be a single integrated part, or can be composed of any number of parts, two or more. As shown in FIG. 8, the storage unit 1A is formed by combining the front part 1B, which is composed of the right front part 2, the center front part 3, and the left front part 4, with the back part 5 shown in FIG. 7. As shown in FIG. 8, when the thickness in the normal direction of the storage unit 1A is minimized, the bending rigidity in that vicinity decreases, which makes it easier to deform the EEG measuring device 1 by, for example, expanding the distance between the ends when the device is attached to the head of a living body, which is preferable.

The storage unit 1A has a shape that allows it to be attached to the head of a living body, and has a curved shape that allows it to be positioned along the user's head from the left side of the head to the front of the head and to the right side of the head when attached to the head of the living body, and maintains its attached state on the head of the living body due to friction when it comes into contact with the head of the living body. In one example, this curved shape is a horizontal curve with respect to the imaginary plane formed by the storage unit 1A.

See Figures 2 to 4. The

measurement electrodes

6, 7 are spaced apart from each other, are placed on the surface of the rear part 5, which is the rear side of the housing part 1A, and come into contact with the user's forehead when the EEG measuring device 1 is worn. The signal processing part is an electronic circuit that processes the electrical signal obtained via at least one of the

measurement electrodes

6, 7, and is housed within the housing part 1A.

More specifically, storage section 1A has a semicircular shape that curves inward toward the head when viewed from above, and has two ends 5E on the left and right. In this embodiment, ends 5E of storage section 1A are also ends of rear part 5, but they can also be ends of front part 1B, i.e., ends of right front part 2 and left front part 4. The semicircular shape of storage section 1A viewed from above has a smaller curvature near ends 5E than the curvature of the central part of the front, and is shaped to fit the head, with the front part close to a circle along the shape of the forehead and the sides close to a straight line along the shape of the sides.

Figures 9 and 10 are schematic diagrams of an electroencephalogram measuring device 1 according to one embodiment of the present invention, as viewed from the right ear side (Figure 9) and the left ear side (Figure 10). As shown in Figures 9 and 10, when the vertical width of the approximate center of the housing section 1A is minimized, the bending rigidity in that vicinity decreases, which is preferable because it makes it easier to deform the device, such as by expanding the distance between the ends, when the electroencephalogram measuring device 1 is attached to the head of a living subject.

Refer to FIG. 3. When the EEG measuring device 1 is not attached to the head, the distance between the two ends 5E is called the device width L1. It is preferable that the device width L1 is a distance slightly smaller than the average head width of the adult who is the main user. In this case, when the EEG measuring device 1 is attached to the head of a living body, the distance between the two ends 5E is expanded to be equal to or larger than the device width L1, and the back side of the EEG measuring device 1 is pressed against the head of the living body by the restoring force from the state in which the distance between the two ends 5E of the EEG measuring device 1 is expanded, and the attached state is maintained by frictional force, etc. Head width is the maximum width of the head measured above the ears so as to be perpendicular to the sagittal plane, and it is known that the average width for Japanese men is 158 to 160 mm, and for Japanese women it is 152 to 153 mm. In one embodiment of the present invention, the device width L1 is set to 155 mm, taking into account the average head width of such Japanese men. If the device width L1 is greater than the width of the user's head, an auxiliary band, described below, can be used to properly press the back of the EEG measurement device 1 against the head and maintain the wearing state.

By appropriately setting the rigidity of the EEG measurement device 1, the restoring force from the expanded distance of the ends 5E is set to an appropriate value that adequately maintains the wearing state while not applying excessive pressure to the head. In one embodiment of the present invention, the rigidity of the EEG measurement device 1 is set so that the force required to expand the distance between the ends 5E to the expected average head width of the user is 5 N·m (0.51 kgf·m) when expressed as a moment with the foremost part (the center of the central front part 3) as the reference point.

The distance from the rear side of the frontmost part of the EEG measuring device 1 to the straight line connecting the two ends 5E is called the device length L2. It is preferable that the device length L2 is a length such that the two ends 5E are located above the left and right auricles when the EEG measuring device 1 is attached to the head of a living body. In one embodiment of the present invention, the device length L2 is 147 mm. Also, in this embodiment, the circumferential length of the rear part 5, i.e., the longitudinal length of the arc-shaped part that contacts the head, is 380 mm. The device width L1 and device length L2 can both be set to appropriate values other than the above values. The weight of the EEG measuring device 1 in one embodiment of the present invention was 81 g.

The pad 50 assists in maintaining the EEG measurement device 1 attached to the head of a living subject by contacting the forehead when the EEG measurement device 1 is attached to the head of the living subject, and is placed near the

measurement electrodes

6, 7 on the surface of the rear part 5. The pad 50 is preferably placed midway between the two

measurement electrodes

6, 7 on the surface of the rear part 5.

Note that all of the drawings are schematic diagrams and the dimensions of each part of the EEG measurement device 1 are not limited to the examples in these drawings, but in one example, the circumferential length of the central front part 3 may be about 30% to about 50% of the circumferential length of the EEG measurement device 1 or front part 1B (excluding protrusions and leg portions; the same applies below), the circumferential length of the left front part 4 may be about 25% to about 35% of the circumferential length of the EEG measurement device 1 or front part 1B, and the circumferential length of the right front part 2 may be about 25% to about 35% of the circumferential length of the EEG measurement device 1 or front part 1B. The circumferential lengths of the left front part 4 and the right front part 2 may be equal to each other or different from each other. With the above configuration, when the EEG measurement device 1 is worn on the head, the housing portion 1A extends in a circular, band-like shape that curves inward toward the left and right auricles along the head, and the left and right ends 5E of the housing portion 1A are positioned near the tops of the left and right auricles, respectively, so that the EEG measurement device 1 comes into appropriate contact with the living head and the worn state is maintained.

11 is a schematic diagram showing an embodiment of the electroencephalogram measuring device 1 according to the present invention worn on the user's head. As shown in FIG. 11, the user wears the electroencephalogram measuring device 1 so that it is positioned along the user's head from the left temporal region to the frontal region to the right temporal region, and the user clips the clip-shaped member (made of an insulating material) so that the reference electrode 8 (a reference electrode 8 is placed on each of the parts on both sides of the clip-shaped member, for a total of two reference electrodes 8, but in the following description, they are collectively referred to as the reference electrodes 8) placed inside the clip-shaped member comes into contact with the ear. As described above, the size of the electroencephalogram measuring device 1 can be appropriately set, but in one example, the height (the maximum length in the short side (up and down) direction when the electroencephalogram measuring device 1 is viewed from the side as in FIG. 9 and FIG. 10) can be 30 mm (excluding the protrusions and legs). The reference electrode 8 may be provided at one end of the longitudinal direction of the storage section 1A.

As will be explained in detail later, the rigidity of at least two of the central front part 3, left front part 4, right front part 2, and rear part 5 differs from one another, and in one example, the material and shape of each part are selected so that the rigidity of the right front part 2 and the left front part 4 is higher than the rigidity of the central front part 3 (and more preferably, so that the rigidity of the right front part 2 and the left front part 4 is higher than the rigidity of the rear part 5). In other words, the rigidity of the parts can be appropriately set by selecting the material and cross-sectional shape of the parts.

The measurement electrode 6 is connected to the signal processing unit 25 via a (coated) conductor, and the measurement electrode 7 is also connected to the signal processing unit 25 via a (coated) conductor. The electroencephalogram measuring device 1 further includes a reference electrode 8, which is connected to the signal processing unit 25 via a (coated) reference electrode lead wire (conductor) 9. In addition, when a GND electrode is provided in the electroencephalogram measuring device 1 (GND electrode 24 in FIG. 16 described later. By contacting the GND electrode 24 with the user's head or any position on the body, a reference potential in the operation of the electroencephalogram measuring device 1 can be applied, and this reference potential can be used as a reference for the potentials of the other electrodes), the GND electrode is connected to the signal processing unit 25 via a (coated) conductor. It should be noted that each of these electrodes is separately connected to the signal processing unit 25 and configured to input an electrical signal to the signal processing unit 25 (a (coated) conductor extends from each electrode separately and is connected to a separate terminal of the signal processing unit 25. The risk of disconnection can be reduced by wiring each (coated) conductor other than the reference electrode lead wire 9 so that it passes only inside the housing unit 1A (there are also cases where the GND electrode 24 is configured to contact a part other than the head, and wiring inside the housing unit 1A is not essential)), and that the electrodes are not short-circuited. The material of each electrode is arbitrary, but in one example, the electrode material can be stainless steel, silver-silver chloride (Ag/AgCl), or silver.
Electrodes such as the measurement electrode 7 and the reference electrode 8 are components necessary for obtaining an appropriate potential difference for measuring electroencephalograms, and for this purpose, it is sufficient that one electrode is in contact with the body surface at a position away from the electrophysiological signal source such as the brain, heart, muscle, etc., and the other electrode is in contact with the body surface near the electrophysiological signal source. For this reason, for example, it is possible to attach the measurement electrode 7 to the earlobe such as the auricle, the outer ear, the posterior auricular muscle, or other area around the ear, and to use the electrode provided on the rear part 5 as the reference electrode 8 and hang the housing part 1A around the neck, etc., to obtain a reference potential.

The shapes of the

measurement electrodes

6 and 7 are arbitrary, but in one example, the contour of the surface (see FIG. 2) that contacts the user's forehead when worn is formed to have a circular shape with a diameter ranging from 10 mm to 25 mm (the same applies when three or more measurement electrodes are provided. Also, it may be adjusted appropriately, such as by providing a recess in part of the circular shape). The shape of the contact surface of the

measurement electrodes

6 and 7 that contacts the user's forehead (forehead) when worn is also arbitrary, and may be, for example, a flat surface as shown in FIG. 3 and FIG. 4, a concave surface (a surface that contacts the forehead is at least partially recessed when viewed from the user when worn), or a convex surface (a surface that contacts the forehead is at least partially protruding when viewed from the user when worn), but in order to give the user a good wearing feeling, it is preferable to use a shape other than a convex surface (the same applies when three or more measurement electrodes are provided). By shaping the

measurement electrodes

6 and 7 to fit the user's forehead, the contact area becomes larger, and it is possible to improve the accuracy of measuring brain waves. The reference electrode 8 and the GND electrode 24 may have the same shape and size and can be appropriately set. In addition, it is preferable to arrange the

measurement electrodes

6 and 7 so that the centers of the contact surfaces (see FIG. 2) of the

measurement electrodes

6 and 7 that come into contact with the forehead when worn are spaced apart from each other on the left and right at intervals ranging from 40 mm to 90 mm along the shape of the back part 5 (along the curve of the back part 5 when the EEG measuring device 1 is viewed from the direction of FIGS. 3 and 4) (when three or more measurement electrodes are provided, each measurement electrode may be arranged at a similar interval). The distance between the

measurement electrodes

6 and 7 is preferably about 20% of the frontal circumference (the length of the head circumference forward of the center of both ears) (furthermore, it is preferable for the user to wear the EEG measuring device 1 so that the midpoint of the center points of the contact surfaces of the

measurement electrodes

6 and 7 that contact the forehead when worn is located at the center of the forehead, that is, on the (extension of) the user's nose line). As a result of measuring the frontal circumference of multiple people, it is considered that the length of 20% of the frontal circumference falls within the range of approximately 40 mm to 90 mm. For example, as an example of the positions of the

measurement electrodes

6 and 7, the positions Fp1 and Fp2 of the International 10-20 system may be used. Here, it is preferable to install the pad 50 at a position corresponding to the center of the forehead. In this case, the pad 50 is located at the midpoint between the

measurement electrodes

6 and 7, and the centers of the contact surfaces of the

measurement electrodes

6 and 7 that contact the forehead when worn are separated from each other on the left and right by a distance in the range of 40 mm to 90 mm along the shape of the back part 5.

The pad 50 will be described in more detail below. The pad 50 according to one embodiment of the present invention is not limited to the specific embodiment described below, and can be modified as appropriate within the scope of the technical concept of the present invention. FIG. 13 shows a partial enlarged view of the measurement electrode and the vicinity of the pad as viewed from above, and FIG. 14 shows a partial enlarged view of the measurement electrode and the vicinity of the pad as viewed from diagonally below the rear. As shown in FIGS. 13 and 14, the pad 50 is preferably provided on the rear side of the storage unit 1A (the side of the living body's head when worn), that is, on the surface of the rear part 5, near the

measurement electrodes

6 and 7. As shown in FIG. 13, the distance between the contact surface of the pad 50 that contacts the living body's head and the surface of the rear part 5 (the surface on the living body's head side) is the pad thickness h1. The distance between the contact surfaces of the

measurement electrodes

6 and 7 that contact the living body's head and the surface of the rear part 5 is the electrode thickness h2. The electrode thickness h2 of the measurement electrode 6 is the distance from the overall surface of the rear part 5 to the contact surface of the measurement electrode 6 that contacts the living body's head.

When the

measurement electrodes

6 and 7 are installed on the rear part 5, the part that is supported by contacting the rear part 5 is called the receiving part. Here, if the receiving part of the rear part 5 on which the

measurement electrodes

6 and 7 are installed is a convex receiving part that is raised from the overall surface of the rear part 5, the electrode thickness h2 is the height of the convex receiving part added to the thickness of the measurement electrode 6 only. Figure 15 shows the A-A cross section around the measurement electrode 6 shown in Figure 13. The measurement electrode 6 has a structure that penetrates the rear part 5 through the receiving part, but this penetrating structure is unrelated to the thickness of the measurement electrode 6. The thickness of the measurement electrode 6 only is the distance from the surface of the receiving part for the measurement electrode 6 to the contact surface of the measurement electrode 6. And the receiving part of the rear part 5 that supports the measurement electrode 6 is a thin cylindrical convex receiving part. Therefore, the electrode thickness h2 is the value obtained by adding the height of the convex receiving part to the distance from the surface of the receiving part for the measurement electrode 6 to the contact surface.

When there is one measurement electrode, two pads 50 may be provided on both ends of the measurement electrode, and the shape of the pads 50 may be changed according to the distance from the electrode. Preferably, the two pads 50 have a slightly elongated shape such as a rectangle or ellipse, and are the same shape, and are installed so that the measurement electrode is located at the midpoint between the pads 50. When there are two measurement electrodes, as shown in Figures 13 and 14, it is preferable to install one pad 50 on the surface of the back part 5 at a position between the

measurement electrodes

6 and 7, within the longitudinal distance between the measurement electrodes (measurement electrodes 6 and 7) and within the width (short direction) of the back part 5. When there are three measurement electrodes, it is preferable to arrange the number of pads 50 to be three or five, for example, and to arrange the measurement electrodes and the pads 50 alternately. When the number of measurement electrodes is four or more, it is preferable to prepare an appropriate number of pads 50, such as (the number of measurement electrodes + 1) or (the number of measurement electrodes - 1), and arrange the measurement electrodes and the pads 50 alternately. In one example, the pad 50 is a rectangle or ellipse with a length of 15 mm and a width of 28 mm. That is, in FIG. 14, when the long direction (major axis) of the ellipse that is the shape of the pad 50 is length d1 and the short direction (minor axis) is length d2, d1 = 28 mm and d2 = 15 mm. When the shape of the pad 50 is rectangular, the long side has a length d1 and the short side has a length d2.

The pad 50 according to the embodiment of the present invention was appropriately selected taking into consideration the material, hardness, tensile strength, and elongation rate from the viewpoint of the sensation it provides to the skin when attached to the head of a living body, its strength, etc. For example, the physical properties table of Aronkasei elastomer can be used as a reference for consideration (https://www.aronkasei.co.jp/elastomer/product/vp.php).

The material of the pad 50 is preferably an elastomer, taking into consideration hardness, strength, flexibility, coefficient of friction, specific heat, processability, etc. It is also possible to use other materials, such as natural rubber, synthetic rubber, resin foam, etc.

In order to provide the appropriate hardness to the user's head when worn, the hardness of the pad 50 is preferably 70 to 97 points, more preferably 73 to 94 points, and most preferably 81 points, according to Japanese Industrial Standard JIS K 6253 Type A.

In order to provide an appropriate strength to the contact surface of the electroencephalogram measuring device with the living head, the tensile strength of the pad 50 is preferably 6.2 to 19.5 MPa, more preferably 7.0 to 14.5 MPa, and most preferably 8.3 MPa, in accordance with Japanese Industrial Standard JIS K 6251.

The elongation of the pad 50 is preferably 440-830%, more preferably 520-710%, and most preferably 610%, in accordance with Japanese Industrial Standard JIS K 6251, so that the contact area has appropriate ductility.

As an example, elastomer VP-A80ET (Aronkasei) (https://www.aronkasei.co.jp/elastomer/product/vp.php) may be used.

The thickness of the pad 50 according to the embodiment of the present invention (the height from the surface of the rear part 5 to the contact surface with the head) can be suitably selected according to the physical properties of the pad (hardness, tensile strength, elongation), the number of measurement electrodes, and the elasticity of the storage part 1A. For example, in one example, a case will be described in which the height of the

measurement electrodes

6, 7 from the rear part 5 is 2 mm. If the thickness of the pad 50 is extremely different from the height from the rear part 5, which is 2 mm, the contact of the

measurement electrodes

6, 7 with the living body's head will be poor, which may impair the EEG measurement.

For example, if the thickness of the

measurement electrodes

6, 7 is too low compared to the thickness of the pad 50, the greater thickness of the adjacent pad 50 makes it difficult for the

measurement electrodes

6, 7 to contact the head. On the other hand, if the height of the measurement electrodes is too high, the pressure applied by the

measurement electrodes

6, 7 when they contact the head is strong, but the back part 5 of the EEG measuring device 1 mainly contacts the head near its end 5E, so the friction between the back part 5 and the head weakens the force that fixes the electrodes in the vertical direction, and the

measurement electrodes

6, 7 are unstable. Therefore, when the pad 50 used in this embodiment has the above physical properties, it is preferable that the thickness of the pad 50 (height from the surface of the back part 5) is approximately equal to the height of the

measurement electrodes

6, 7 from the surface of the back part 5. In other words, it is preferable that the contact surface of the pad 50 with the head and the contact surface of the

measurement electrodes

6, 7 with the head are on the same curved surface that follows the contour of the head. Regarding the degree of wearing comfort (degree of pain), factors such as the hardness, area and shape of the contact part, friction coefficient, difference in thickness between the pad 50 and the

measurement electrodes

6 and 7, and the gap between the pad 50 and the

measurement electrodes

6 and 7 when worn (ease of the skin to be bitten, i.e., the amount of space the skin can escape when pressed) are considered to be factors, as well as the shape of the subject's forehead and the thickness of the skin. On the other hand, regarding the signal quality, factors such as the intensity of the subject's brain waves, the fixed position of the measurement electrodes relative to the skull, the degree of shielding by subcutaneous fat, and the performance of the signal amplifier chip (brain wave sensor chip) of the signal processing unit are considered to be factors. However, the difference in thickness between the pad 50 and the

measurement electrodes

6 and 7 has a large effect on the performance of the EEG measuring device 1, such as the wearing comfort and signal quality.

Refer back to FIG. 1. As shown in FIG. 1, the right front part 2 is provided with an operation unit 10, specifically a power button, and the user can press the power button to switch the operation of the EEG measuring device 1 between on (operating state) and off (stopped state). The right front part 2 is also provided with an indicator LED (light emitting diode) 11, which can be turned on, off, flashing, or the color of the light emitted can be changed depending on the operating state or charging state. The right front part 2 is also provided with a charging port (charging inlet) 12, and the lithium ion battery of the power supply unit 32 (see FIG. 16) can be charged by opening the charging port cover 13 and connecting a charging cable to the charging port 12. As shown in FIG. 2, a non-slip sheet 14 (right side) is provided at a position of the back side component 5 corresponding to the right front side component 2, and as shown in FIG. 3, a non-slip sheet 15 (left side) is provided at a position of the back side component 5 corresponding to the left front side component 4, to prevent the electroencephalogram measuring device 1 from slipping off the head when worn on the user's head. The material of the

non-slip sheets

14, 15 is arbitrary, but in one example, urethane, silicone, etc. can be used as the material of the

non-slip sheets

14, 15. Also, as shown in FIG. 2, an auxiliary band attachment hole 16 (right side) is provided at an end of the back side component 5 on the right front side component 2 side, and an auxiliary band attachment hole 17 (left side) is provided at an end of the back side component 5 on the left front side component 4 side. By passing one end and the other end of a wearing auxiliary band (belt) 19 shown in FIG. 12 through the auxiliary band attachment holes 16, 17, respectively, and connecting the wearing auxiliary band 19 to the electroencephalogram measuring device 1 (the rectangular ring-shaped portion attached to the hook-and-loop fastener hook portion 21A side at one end of the wearing auxiliary band 19 in FIG. 12 ), The ring-shaped member 20 is turned sideways (the hook and

loop fastener parts

21A and 21B on both ends are bendable) and passed through the auxiliary band attachment hole 16, the ring-shaped member 20 on the hook and loop fastener part 21A sideways and passed through the auxiliary band attachment hole 17, and each hook and loop fastener part 21A is folded back and attached to the hook and loop fastener part 21B), improving the stability of the position of the electroencephalogram measuring device 1 when worn. Also, if the device width L1 is larger than the width of the user's head, the user can wear the wearing auxiliary band 19 and tighten and fix it with an appropriate force, so that the storage part 1A can contact the living body's head with an appropriate force.

5 is an exploded view (perspective view) of the housing 1A when disassembled into each component part. By making the front side part 1B a divided structure in this way, the wearing comfort for the user is improved. In one example, the signal processing part 25 and the communication part 29 shown in FIG. 16 are configured by arranging each circuit element, device, etc. on a circuit board, and the circuit board is arranged at the circuit board accommodation position 22 in the space between the left front side part 4 and the rear side part 5 (the position of the circuit board is arbitrary, and it is preferably arranged between the left front side part 4 and the rear side part 5, or between the right front side part 2 and the rear side part 5. In an embodiment in which the rigidity of the left front side part 4 and the right front side part 2 is higher than the rigidity of the central front side part 3 and higher than the rigidity of the rear side part 5, the circuit board is protected from impact by arranging the circuit board in this way.). The right front part 2, the central front part 3, the left front part 4, and the rear part 5 are manufactured by selecting materials, shapes, etc. so that the rigidity of at least two of them differs from each other, and it is particularly preferable to manufacture each part so that the rigidity of the right front part 2 and the left front part 4 is higher than the rigidity of the central front part 3 and higher than the rigidity of the rear part 5. A reinforcing member can be used to screw the central front part 3 and the rear part 5 together.

In this embodiment, "rigidity" is determined by the Young's modulus (modulus of longitudinal elasticity) of the material and the second moment of area due to the cross-sectional shape for a member of a certain length. In other words, assuming that the lengths of the parts are the same, if the Young's modulus of the material of one part is higher than the Young's modulus of the material of another part when the parts have the same cross-sectional shape, or if the second moment of area of one part is larger than the second moment of area of another part when the parts are made of materials with the same Young's modulus, then "the rigidity of one part is higher than the rigidity of another part." However, in this embodiment, the Young's modulus due to the material has a greater contribution to the rigidity of the part than the second moment of area due to the cross-sectional shape. In other words, a more appropriate rigidity for each part is achieved mainly by selecting the appropriate material for each part. As a method for measuring Young's modulus, for example, the right front component 2 is punched out to prepare a sample with a length and width of approximately 1.8 mm in the surface direction (the direction of the surface that is roughly parallel to the rear component 5 when the accommodation portion 1A is formed) and a thickness of approximately 0.1 mm in the direction perpendicular to the surface direction (strictly speaking, it is a curved surface, but it is approximately considered to be a flat surface), and this is used as a test sample. As described in paragraph [0118] of the specification of Patent No. 6,857,784, a tensile test is carried out in physiological saline at 20°C using a Shimadzu precision universal testing machine Autograph AG-IS MS model manufactured by Shimadzu Corporation, and the Young's modulus (MPa) is calculated as the tensile elastic modulus from the stress-elongation curve (tensile speed is 100 mm/min), whereby the Young's modulus of the right front component 2 can be measured. The Young's modulus of other parts, such as the central front part 3, the left front part 4, and the back part 5, can be measured in the same manner (the "face direction" of the sample of the back part 5 may be the direction of the surface that is roughly parallel to the "face direction" of the sample of the right front part 2, for example).

The materials of the right front side component 2, the central front side component 3, the left front side component 4, and the rear side component 5 may be any material, and the Young's modulus of these components may be any value. In one example,
The Young's modulus (tensile modulus) of the central front side part 3 is 49.5 MPa (megapascals) (manufactured by DuPont-Toray Co., Ltd., material: thermoplastic polyester elastomer, Hytrel (registered trademark), grade: 4047N. The test method is in accordance with Japanese Industrial Standard JIS K7113-1995).
The Young's modulus (tensile modulus) of both the right front side component 2 and the left front side component 4 is 2550 MPa (megapascals) (manufactured by Mitsubishi Engineering Co., Ltd., material: PBT resin (polybutylene terephthalate resin), Novaduran (registered trademark), grade: 5010R5. Test method is in accordance with ISO 527-1, 527-2).
The Young's modulus (tensile modulus) of the back side part is 1350 MPa (megapascals) (Japan Polypropylene Corporation, material: PP (polypropylene), Novatec (registered trademark), grade: BC4BSW. The test method complies with Japanese Industrial Standard JIS K7161 7162:1994).
Each part can be manufactured in this manner (the physical properties of each material are the specifications published by the manufacturer, so the test methods differ, but the magnitude relationship of Young's modulus remains unchanged even if the test method is standardized).
The second moment of area can be calculated from the cross-sectional shape by a known formula. By reducing the thickness in the normal direction of the central front part 3 located approximately in the center of the housing part 1A, the cross-sectional shape of the central front part 3 can have a smaller second moment of area and a smaller rigidity.

FIG. 16 is a block diagram showing the configuration of an EEG measuring device according to one embodiment of the present invention, and FIG. 17 is a block diagram showing the configuration of a data collection terminal device. In this embodiment, EEG data obtained by measurement using the EEG measuring device 1 is transmitted from the EEG measuring device 1 to a data collection terminal device 33, where analysis and processing of the EEG data are performed.

16, the EEG measuring device 1 includes N (N is a natural number equal to or greater than 1) measurement electrodes, namely measurement electrode 6 to Nth measurement electrode 23 (measurement electrode 23 is not necessary if there is only one measurement electrode), a REF electrode (reference electrode) 8, a GND electrode 24, a signal processing unit 25, a communication unit 29, an operation unit 10, an LED display 11, and a power supply unit 32. As already mentioned, each electrode is separately connected to the signal processing unit 25, and the electrical signal from each electrode is input to an amplifier circuit 26 of the signal processing unit 25.

The signal processing unit 25 includes an amplifier circuit 26, an A/D converter (Analog-to-Digital Converter) 27, and a digital signal processing unit 28. The amplifier circuit 26 is a circuit that amplifies the bioelectric potential input as an electrical signal from the various electrodes, and performs processes such as measuring the potential difference between the measurement electrode 6 and the reference electrode 8, amplifying this potential difference, and outputting it to the A/D converter 27, and measuring the potential difference between the measurement electrode 7 and the reference electrode 8, amplifying this potential difference, and outputting it to the A/D converter 27 (the same applies when the number of measurement electrodes is three or more). The A/D converter 27 is a conversion circuit that converts analog signals into digital signals, and converts the various potential differences input as analog signals from the amplifier circuit 26 from analog signals to digital signals and outputs them to the digital signal processing unit 28. As described above, the digital signal processing unit 28 is composed of a CPU, RAM (Random Access Memory), ROM (Read Only Memory), and other memory devices, and processes the digital signal input from the A/D converter 27 to generate, for example, a digital signal that indicates the potential difference between the measurement electrode 6 and the reference electrode 8 as a numerical value, or a digital signal that indicates the potential difference between the measurement electrode 7 and the reference electrode 8 as a numerical value (similarly when the number of measurement electrodes is three or more), and outputs these digital signals to the communication circuit 31 of the communication unit 29. The digital signal processing unit 28 may also perform processing such as FFT (Fast Fourier Transformation) on the digital signal input from the A/D converter 27 by the CPU executing a program stored in the memory device, and output a digital signal indicating the obtained result to the communication circuit 31 of the communication unit 29.

The communication unit 29 includes an antenna 30 and a communication circuit 31. The communication circuit 31 transmits the digital signal input from the digital signal processing unit 28 to the data collection terminal device 33 via the antenna 30. In one example, the communication unit 29 wirelessly communicates with the communication unit 42 of the data collection terminal device 33 using the BLE (Bluetooth Low Energy) method.

As already explained, the operation unit 10 is specifically a power button, and when the user presses the power button, the operation of the EEG measurement device 1 is switched on (operating state) and off (stopped state). The display LED 11 turns on, off, blinks, and changes its light color depending on the operating state and charging state. The power supply unit 32 includes a lithium ion battery and circuits for supplying power to each part of the EEG measurement device 1, and is located inside the housing unit 1A.

As shown in FIG. 17, the data collection terminal device 33 includes a control unit 34, a memory unit 37, a communication unit 42, an input/output unit 45, and a power supply unit 49.

The control unit 34 includes a CPU 35 and a RAM 36 as a temporary memory. The CPU 35 executes a measurement program 38 recorded in the storage unit 37, whereby the CPU 35 processes the EEG measurement data received from the EEG measurement device 1 to perform various measurement processes (when the above-mentioned FFT is performed on the data collection terminal device 33 side, a program for performing the FFT is stored in the storage unit 37 as the measurement program 38). The CPU 35 also executes and controls various operations of the data collection terminal device 33 by executing various programs 39, such as an OS (Operating System) and various applications, stored in the storage unit 37.

The storage unit 37 is a recording device equipped with a hard disk drive, SSD (Solid State Drive), etc., and stores the above-mentioned measurement program 38 and various programs 39. The storage unit 37 also stores measurement data 40 (data of the analysis results obtained by executing FFT processing, etc.) and various data 41.

The communication unit 42 includes an antenna 43 and a communication circuit 44. The communication circuit 44 transmits and receives data, such as receiving EEG measurement data from the EEG measurement device 1, via the antenna 43. In one example, the communication unit 42 wirelessly communicates with the communication unit 29 of the EEG measurement device 1 using the BLE method.

The input/output unit 45 includes a keyboard 46 and a mouse 47 for the operator of the data collection terminal device 33 (the person analyzing the electroencephalogram measurement data) to input commands and data into the data collection terminal device 33, and a display device 48 (such as a liquid crystal display device or an organic electroluminescence (organic EL) display device) for displaying various information. In addition, the input/output unit 45 may include an output device such as a speaker.

The power supply unit 49 includes circuits for receiving power from an external power source and supplying power to each part of the data collection terminal device 33, and may also include a battery such as a lithium-ion battery.

FIG. 18 is a flow chart showing the operation of an electroencephalogram measuring device and a data collection terminal device according to one embodiment of the present invention. First, a user (subject) of the electroencephalogram measuring device 1 starts up the electroencephalogram measuring device 1 by pressing and holding down the power button as the operation unit 10 for about 1 to 2 seconds (step S101). It is assumed that the data collection terminal device 33 has already started up. When the electroencephalogram measuring device 1 starts up, a BLE connection is established between the communication unit 29 of the electroencephalogram measuring device 1 and the communication unit 42 of the data collection terminal device 33, provided that the BLE connection is enabled on the data collection terminal device 33 side (step S102). The user of the electroencephalogram measuring device 1 wears the electroencephalogram measuring device 1 on his/her head as shown in FIG. 11, and brings the

measurement electrodes

6, 7 into contact with his/her forehead, preferably so that the

measurement electrodes

6, 7 are positioned symmetrically with respect to the center line of the head, and brings the reference electrode 8 into contact with his/her ear. Furthermore, if the EEG measurement device 1 is equipped with a GND electrode 24, the GND electrode 24 is placed in contact with the subject's head or any position on the body.

In this state, the potential difference between the potential of the measurement electrode 6 and the potential of the reference electrode 8 is amplified by the amplifier circuit 26, the amplified analog signal is converted into a digital signal by the A/D converter 27, the digital signal generated by the conversion by the A/D converter 27 is processed by the digital signal processing unit 28 (step S103), and the digital signal generated thereby, which indicates the change over time in the potential difference between the potential of the measurement electrode 6 and the potential of the reference electrode 8, is transmitted from the communication unit 29 of the EEG measurement device 1 to the communication unit 42 of the data collection terminal device 33 (step S104). Similarly, the potential difference between the potential of the measurement electrode 7 and the potential of the reference electrode 8 is amplified by the amplifier circuit 26, the amplified analog signal is converted into a digital signal by the A/D converter 27, the digital signal generated by the conversion by the A/D converter 27 is processed by the digital signal processing unit 28 (step S103), and the digital signal generated thereby, which indicates the time change of the potential difference between the potential of the measurement electrode 7 and the potential of the reference electrode 8, is transmitted from the communication unit 29 of the electroencephalogram measurement device 1 to the communication unit 42 of the data collection terminal device 33 (step S104). When there are three or more measurement electrodes, a digital signal indicating the time change of the potential difference between the potential of each measurement electrode and the potential of the reference electrode 8 is similarly generated and transmitted from the communication unit 29 of the electroencephalogram measurement device 1 to the communication unit 42 of the data collection terminal device 33. These processes on the electroencephalogram measuring device 1 side are repeatedly performed at a predetermined time interval unless the power button as the operation unit 10 of the electroencephalogram measuring device 1 is pressed again for about 1 to 2 seconds to turn off the electroencephalogram measuring device 1 (NO in the judgment process of step S105). When the CPU 35 of the data collection terminal device 33 starts execution of a measurement application (which is assumed to be included in the measurement program 38) in response to an input from the operator of the data collection terminal device 33, the CPU 35 executing the measurement program 38 continues to store electroencephalogram data (data on time change in potential difference, etc.) of each channel (in one example, the potential difference between the potential of the measurement electrode 7 and the potential of the reference electrode 8 is the potential difference of the first channel, and the potential difference between the potential of the measurement electrode 6 and the potential of the reference electrode 8 is the potential difference of the second channel) in the storage unit 37 as measurement data 40 based on the digital signal received from the electroencephalogram measuring device 1. In response to input from the operator of the data collection terminal device 33 (tapping the measurement end button on the display device 48), storage of the EEG data in the memory unit 37 is terminated, and in response to input from the operator of the data collection terminal device 33 (disconnection of the communication connection with the EEG measurement device 1), the BLE connection between the EEG measurement device 1 and the data collection terminal device 33 is released (disconnected). When the power button serving as the operation unit 10 of the EEG measurement device 1 is pressed again for about 1 to 2 seconds to turn the power of the EEG measurement device 1 OFF (YES in the determination process of step S105), the operation of the EEG measurement device 1 stops (step S106).

Example 1
As an embodiment of the present invention, an electroencephalogram measuring device having the following configuration was manufactured and a performance test was carried out.
(Electroencephalogram Measuring Apparatus of the Example)
・Shape: Shape as shown in Figure 1 etc. ・Number of measurement electrodes (forehead electrodes): 2 (CH1, CH2)
・Pads are not used ・Spacing of forehead electrodes (between the centers of contact surfaces)... 60 mm
・Shape of the forehead electrode: Flat type, the outline of the contact surface is a circle with a diameter of 15 mm ・Shape of the reference electrode (ear electrode): Concave type, the outline of the contact surface is a circle with a diameter of 15 mm ・Materials of each component of the housing part (Central front part 3) Thermoplastic polyester elastomer Hytrel (registered trademark) manufactured by Toray DuPont Co., Ltd. Grade: 4047N. Young's modulus 49.5 MPa (Test method conforms to Japanese Industrial Standard JIS K7113-1995)
(Right front part 2 and left front part 4) PBT resin (polybutylene terephthalate resin) manufactured by Mitsubishi Engineering Co., Ltd. Novaduran (registered trademark) Grade: 5010R5. Young's modulus 2550 MPa (test method conforms to ISO 527-1, 527-2)
(Back side part 5) Made by Japan Polypropylene Corporation Material: PP (polypropylene) Novatec (registered trademark) Grade: BC4BSW. Young's modulus 1350 MPa (Test method conforms to Japanese Industrial Standard JIS K7161 7162:1994)

When subjects wore the electroencephalography device with the above configuration on their heads to check the fit, the contact of the forehead electrode was improved compared to prototypes with convex curved electrodes (15 mm diameter) and concave curved electrodes (20 mm diameter), the clamping strength of the ear electrodes was improved compared to the flat prototype with a diameter of 11 mm, and by selecting the above material, the feeling of tightness around the temples was reduced and pain was eliminated.

Furthermore, an electroencephalogram measurement test was conducted on subjects using the electroencephalogram measurement device of the above embodiment, and the consistency of the results with those of an electroencephalogram measurement test conducted using an existing measurement device, Polymate (registered trademark) (Miyuki Giken Co., Ltd.) was verified. The correlation coefficients of the results of both tests are shown in Tables 1 to 4 below.

As can be seen, the correlation coefficients are generally high, and the EEG measurement device of Example 1 provided good results in terms of both the subject's wearing comfort and the consistency of the measurement results with existing EEG measurement devices.

Example 2
As an embodiment of the present invention, an electroencephalogram measuring device having the following configuration was manufactured and a performance test was performed. Here, in order to investigate the thickness of the measurement electrode suitable for electroencephalogram measurement, an electroencephalogram measuring device was manufactured by changing the thickness of the measurement electrode (electrode thickness h2), and the device was attached to four subjects, and the signal quality of the electroencephalogram and the wearing comfort of the electroencephalogram measuring device were measured.
(Test Method)
(1) Using two measuring electrodes spaced apart from each other on the left and right, the thickness from the surface of the backside part to the contact surface of the measuring electrodes was changed in 1 mm increments from 0 mm to 5 mm (0 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm) to produce measuring electrodes and conduct the test. No pads were used.
(2) The measurement electrodes were fixed so that they protruded from the rear part by the thickness of each electrode, and the test was performed in accordance with the specified standards.
(3) When the signal quality was continuously stable, the subject judged it as "stable", when the signal quality was intermittently stable, it was "unstable", and when the signal quality could not be acquired, it was "not good". In addition, regarding the comfort of wearing, the pain (comfort of wearing) was also evaluated in a state where the stability of the signal quality was ensured, and the judgment result was either "good", "average", or "not good". The subjects used were subject A, who had a typical and symmetrical forehead shape, subject B, who had a more convex forehead shape than the typical, subject C, who had a more concave forehead shape than the typical, and subject D, who had a more wavy forehead shape than the typical, so that the results would be suitable for a wide range of users.
(Results) The subjects wore the electroencephalogram measuring device of each of the above configurations on their heads, and the performance test and fitting comfort were confirmed. The judgment results are summarized in the following Table 5 (titled "Relationship between the thickness of the measurement electrode (height from the surface of the back part of the contact surface of the contact electrode) and the signal quality/pain"). As shown in Table 5, the measurement electrode thickness of 2 mm gave the best results for both the electroencephalogram signal quality and the fitting comfort of the electroencephalogram measuring device for all four subjects. Even when the measurement electrode thickness was 1 mm and 3 mm, the fitting comfort was "good" and the signal quality was "unstable" only for some subjects, so it is considered that there are generally no practical problems. Even when the measurement electrode thickness was 4 mm, there were no subjects whose performance test and judgment results were "fail," and it is considered that the device can be used practically. Therefore, the thickness of the measurement electrode is preferably in the range of 1 mm to 4 mm, more preferably in the range of 1 mm to 3 mm, and most preferably 2 mm.

Example 3
In order to investigate the appropriate pad thickness for EEG measurement, the thickness of the measurement electrode (electrode thickness h2) was fixed at 2 mm, which produced the best results in Example 2, and the thickness of the pad (pad thickness h1) was varied to create EEG measurement devices. These devices were then fitted to the same four subjects as in Example 2, and the EEG signal quality and the fit of the EEG measurement device were measured.
(Test Method)
(1) An electroencephalogram (EEG) measuring device having two measuring electrodes spaced apart on the left and right sides was used, and a pad to be placed between them was cut using a cutter knife to a length of 15 mm, a width of 28 mm, and a thickness that was changed in 1 mm increments from 1 mm to 5 mm (1 mm, 2 mm, 3 mm, 4 mm, 5 mm). Tests were conducted including a case where a pad was not attached.
(2) The pad was fixed between two measurement electrodes on the surface of the back part, and the test was performed in accordance with the specified standards.
(3) If the signal quality from the subject was continuously stable, it was judged as “stable”; if the signal quality was intermittently stable, it was judged as “unstable”; and if the signal quality could not be obtained, it was judged as “unstable.”
(Results) A performance test was conducted by having subjects wear the electroencephalogram measuring device of each of the above configurations on their heads, and the results are summarized in Table 6 below (titled "Relationship between pad thickness (height of the contact surface of the pad from the surface of the backside part) and signal quality"). As shown in Table 6, when the pad thickness (pad thickness h1) was 2 mm, good results were obtained in terms of electroencephalogram signal quality for all four subjects. When the pad thickness was 1 mm and 3 mm, the number of subjects whose performance test results were "fail" was less than half, and it is considered that there are generally no problems in practical use. Even when the pad thickness was 4 mm, there were subjects whose performance test results were other than "fail," and it is considered that the device can be used practically. Therefore, the pad thickness is preferably in the range of 1 mm to 4 mm, more preferably in the range of 1 mm to 3 mm, and most preferably 2 mm. Therefore, taking into consideration the results of Example 2, in the case of the electroencephalogram measuring device used in this example (where the measuring electrodes are installed at predetermined positions), it is most preferable that the thickness of the pad is about 2 mm from the surface of the rear part, and the thickness of the measuring electrodes from the surface of the rear part is 2 mm. In this case, the thickness of the pad is about 2 mm from the surface of the rear part, and is almost equal to the thickness of the measuring electrodes from the surface of the rear part. Also, if the thickness of the pad is in the range of 1 mm to 4 mm from the surface of the rear part, and the thickness of the pad at that time is in the range of -1 mm to +1 mm with respect to the thickness of the measuring electrodes from the surface of the rear part, the electroencephalogram measuring device is considered to be practically usable.

The present invention can be used for measuring brain waves in any industry, including medical equipment and research equipment.

1 EEG measuring device 1A Storage section 1B Front part 2 Right front part 3 Center front part 4 Left front part 5 Back part 6 (Right side) Measurement electrode (forehead electrode)
7 (Left side) Measuring electrode (forehead electrode)
8 Reference electrode (REF electrode, ear electrode)
9 (coated) reference electrode lead wire 10 Power button (operation unit)
11. Display LED
12 Charging port 13 Charging port cover 14 (right side) Anti-slip sheet 15 (left side) Anti-slip sheet 16 (right side) Auxiliary band attachment hole 17 (left side) Auxiliary band attachment hole 18 Human head 19 Wearing auxiliary band 20 Ring-shaped member 21A Hook-and-loop fastener (hook)
21B Hook and loop fastener (loop)
22 Circuit board housing position 23 Nth measurement electrode (N is 2 or more)
24 Ground electrode (GND electrode)
25 Signal processing unit 26 Amplification circuit 27 A/D (analog/digital) converter 28 Digital signal processing unit 29 Communication unit 30 Antenna 31 Communication circuit 32 Power supply unit (lithium ion battery, etc.)
33 Data collection terminal device 34 Control unit 35 CPU
36 RAM
37 Memory section 38 Measurement program 39 Various programs 40 Measurement data 41 Various data 42 Communication section 43 Antenna 44 Communication circuit 45 Input/output section 46 Keyboard 47 Mouse 48 Display device 49 Power supply section 50 Pad

Claims

An electroencephalogram measuring device that can be attached to the head of a living body,
A storage section including at least a front part and a back part, the storage section having a curved shape so as to be disposed along the living body's head from the left head to the front head and the right head when the storage section is attached to the living body's head;
A measurement electrode is installed on the surface of the back part and contacts the forehead when worn;
a signal processing unit contained in the container that processes an electrical signal obtained via the measurement electrodes;
a pad disposed on a surface of the back component adjacent to the measurement electrode;
An electroencephalogram measuring device comprising:
The electroencephalogram measuring device of claim 1, wherein the pad is made of elastomer.
The electroencephalogram measuring device according to claim 2, wherein the elastomer has a hardness value of 70 to 94 according to Japanese Industrial Standards JIS K 6253 type A.
The electroencephalogram measuring device of claim 1, wherein the thickness of the pad is in the range of 1 mm to 4 mm from the surface of the rear part.
The electroencephalogram measuring device of claim 4, wherein the thickness of the pad is in the range of -1 mm to +1 mm relative to the thickness of the rear part of the measurement electrode from the surface.
The electroencephalogram measuring device of claim 5, wherein the thickness of the pad is approximately 2 mm from the surface of the rear part and is approximately equal to the thickness of the measurement electrode from the surface of the rear part.
The electroencephalogram measuring device according to claim 1, wherein the number of the measurement electrodes is at least two, the pad is located at a midpoint between two of the measurement electrodes, and the centers of the contact surfaces of the measurement electrodes that come into contact with the forehead when worn are spaced apart from each other on the left and right sides by a distance in the range of 40 mm to 90 mm along the shape of the back part.
The electroencephalogram measuring device according to claim 7, wherein the contour of the contact surface of the measurement electrode that contacts the forehead when worn is a circle having a diameter in the range of 10 mm to 25 mm.
The biometric device according to any one of claims 1 to 8, wherein the distance between the ends of the housing expands when the housing is attached to the head of the living body, and the housing maintains its attached state on the head of the living body by a restoring force from the expanded state.
A pad for an electroencephalogram measuring device that can be attached to the head of a living body,
The electroencephalogram measuring device comprises:
A storage section including at least a front part and a back part, the storage section having a curved shape so as to be disposed along the living body's head from the left head to the front head and the right head when the storage section is attached to the living body's head;
A measurement electrode is installed on the surface of the back part and contacts the forehead when worn;
A signal processing unit is contained in the container and processes an electrical signal obtained via the measurement electrode.
A pad for an electroencephalogram measuring device, characterized in that the pad is placed on the surface of the rear part in the vicinity of the measurement electrodes.