JP2006034429A - Electrode device for detecting brain wave - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a highly precise electroencephalography by stabilizing a contact state between the scalp and electrodes by the presence of hair when adopting a pasteless brain wave signal detecting method. <P>SOLUTION: The subject electrode device for detecting the brain wave, which is disposed in contact with the scalp A having the hair B and detects brain wave signals, is provided with the metal electrodes 9 and caps 11 coveringly disposed on the tip surfaces of the metal electrodes 9 and having elastic members 10 containing electrolyte. The area of the tip face of the cap 11 coming into contact with the scalp is approximately not less than 19 mm<SB>2</SB>and not more than 314 mm<SB>2</SB>. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrode device for detecting an electroencephalogram.

  Conventionally, analysis of brain function states has been performed for the purpose of early detection of Alzheimer's disease, and various methods for analyzing brain function states have been proposed (see, for example, Non-Patent Document 1 and Non-Patent Document 2). . In this analysis method, an electroencephalogram signal is detected, and the determination is made based on the smoothness of the spatial transmission and the standard deviation. When brain neuron activity is normal, the electroencephalogram signal is transmitted smoothly and there is little variation. It is lost and its standard deviation tends to increase.

  In order to perform such an analysis with high accuracy, it is indispensable to detect an electroencephalogram signal with high accuracy. Electroencephalogram signals are detected by bringing multiple electrodes into contact with the scalp, but in order to achieve a reliable contact between the electrode and the scalp due to the presence of hair and the unevenness of the shape of the head, the electrodes must be applied with paste. It is common to adhere to the scalp. However, when using a paste, it takes a long time to start the inspection, and the burden on the person to be inspected is great. Also, when removing the electrode after the inspection, the hair can be removed to remove the paste. There is an inconvenience that work is required and the burden on the inspected person is large.

On the other hand, pasteless electroencephalogram signal detection methods that do not use paste have also been proposed (see, for example, Patent Document 1 and Patent Document 2). These detection methods are methods in which a fiber piece in a state where water is absorbed in a conductive solution or a water-containing gel impregnated with conductivity is impregnated into a foaming material, and each electrode is brought into contact with the scalp, and no paste is used. Therefore, there is an advantage that the time required for mounting and dismounting can be shortened.
Brain Function Research Institute, Inc., “DIMENSION, a new EEG analysis method for detecting functional deterioration of brain cortical neurons in early Alzheimer's disease”, [online], [March 8, 2004 search], Internet <URL: http : //www.bfl.co.jp/abst-32.html> Brain Function Laboratory Co., Ltd., “Method of Estimating Deterioration of Brain Cortical Neuron Function”, [online], [Search March 8, 2004], Internet <URL: http://www.bfl.co.jp/ abst-31.html> JP-A-10-165386 (second page, etc.) Japanese Utility Model Publication No. 2-63811 (FIG. 1 etc.)

  However, the scalp on which the electrode is placed generally has hair, and in the case of the pasteless EEG signal detection method, the contact state is unstable due to the hair sandwiched between the electrode and the scalp. There was a problem that it was easy to become.

  The present invention has been made in view of the above-described circumstances. When a pasteless electroencephalogram signal detection method is employed, the contact state between the scalp and the electrode is stabilized even with the presence of hair, and high-accuracy inspection is performed. An object of the present invention is to provide an electrode device for detecting an electroencephalogram that can be performed.

In order to achieve the above object, the present invention provides the following means.
The present invention relates to an electroencephalogram detection electrode device that is arranged in contact with a scalp having scalp hair and detects an electroencephalogram signal, comprising: a metal electrode; and an elastic member including an electrolytic solution that is disposed on the front surface of the metal electrode. And an electrode device for detecting an electroencephalogram having an area of a tip end surface of the cap contacting the scalp of about 19 mm ² or more and about 314 mm ² or less.

According to the present invention, when the electroencephalogram detection electrode device is pressed against the scalp having scalp hair, the tip surface of the cap having the elastic member containing the electrolyte solution scrapes the scalp and contacts the scalp. The scalp is pinched between the cap tip and the scalp, but by setting the area of the cap tip to about 19 mm ² or more, it is sufficient for the scalp exposed by scraping the hair. It is possible to make contact in a wide area, and the contact resistance can be reduced. In addition, as the area of the cap tip surface increases, more hair is sandwiched between the cap tip surface and the scalp, so contact resistance will not improve even if the area of the cap tip surface is increased. Absent. On the other hand, if it is set to be larger than about 314 mm ² , it may interfere with the adjacent electrode device, which is not preferable. Therefore, if it is set to about 314 mm ² or less, there is no such inconvenience.

  In the above invention, it is preferable that the metal electrode is made of gold or plated with gold. By configuring the metal electrode by gold or gold plating, it is possible to reduce the electric resistance value and to prevent the electric resistance value from increasing with use due to the rust prevention effect.

  Moreover, in the said invention, the said electrolyte solution is good also as consisting of a physiological saline. The electrolytic solution may be a mixed solution of physiological saline and alcohol. According to these electrolytic solutions, the electric resistance value is low and the detected electroencephalogram signal is not lowered. Moreover, by mixing alcohol, there exists a washing | cleaning effect of the sebum in a scalp, and a contact resistance value can further be reduced.

Further, in the above invention, a plurality of tip portions that are spaced apart from each other are provided, a metal electrode is disposed at the tip of each tip portion, and the total area of the cap tip surface covering all the metal electrode surfaces is It may be about 19 mm ² or more and about 314 mm ² or less.
If the total area is about 19 mm ² or more, the contact resistance value can be reduced. Moreover, by dividing into a plurality of tip portions, the scalp hair can be disposed between the tip portions, and the tip portions can be brought into close contact with the scalp.

Moreover, in the said invention, it is good also as the front-end | tip part of the said metal electrode being formed in a substantially spherical shape, and the said cap front-end | tip surface being formed in the substantially spherical shape in alignment with the front-end | tip part of a metal electrode.
In this way, even when the shape of the head is complicated and the metal electrode cannot be brought into vertical contact with the scalp, the contact resistance value is reduced and reliable contact is achieved. be able to.

The present invention also relates to an electroencephalogram detection electrode device for detecting an electroencephalogram signal in contact with a scalp having scalp hair, and comprising an integrated metal electrode having a plurality of tip portions, and a covering arrangement on the tip portion surface of the metal electrode And a cap having an elastic member containing an electrolytic solution, and an electroencephalogram detection electrode device having a total area of a tip portion of about 19 mm ² or more and about 314 mm ² or less.
Multiple tips of the integrated metal electrode function like comb teeth to scrape the hair, making it possible to contact the exposed scalp with sufficient space by scraping the hair and reducing contact resistance. Can be reduced.

  According to the present invention, it is possible to provide an electrode device for detecting an electroencephalogram capable of accurately detecting an electroencephalogram signal by reducing a contact resistance value in the case of contact with a scalp having scalp hair.

An electroencephalogram detection electrode device according to an embodiment of the present invention will be described below with reference to FIGS.
An electroencephalogram detection electrode device 1 according to the present embodiment (hereinafter simply referred to as an electrode device 1) is used in a brain function detection system 2 shown in FIG. The brain function detection system 2 includes an electroencephalogram detection device 3 having a plurality of electrode devices 1 arranged in contact with the scalp A, a brain function analysis device 4, and a monitor 5 that displays the analysis result.

  The electroencephalogram detection device 3 is an electroencephalograph, and a plurality of electrode devices 1 arranged in contact with the scalp A (FIG. 1 shows five electrode devices 1 for ease of illustration. As shown in FIG. 2, there are 21 electroencephalogram signal detectors 6), and an electroencephalograph main body 7 that outputs an electric signal S 1 detected by the electrode device 1 as an electroencephalogram signal S 2. .

  As shown in FIGS. 2A to 2C, the electroencephalogram signal detection unit 6 has a plurality of electrode devices 1 arranged at a predetermined ratio with respect to the scalp with reference to the reference position. As shown in FIG. 3, the electrode device 1 includes a metal electrode 9 disposed at the tip of a cylindrical electrode device body 8, an elastic member 10 disposed so as to cover the metal electrode 9, and the elasticity A cap 11 attached to the electrode device main body 8 is provided to hold the member 10 on the metal electrode 9 in a covered state.

The metal electrode 9 is made of, for example, gold or a disk-shaped plate having a surface plated with gold. The metal electrode 9 is provided with a wiring 12 penetrating through the inside of the electrode device main body 8, and transmits an electric signal S 1 detected by the metal electrode 9 to the electroencephalograph main body 7.
The elastic member 10 is, for example, a substantially disc-shaped sponge member, and is impregnated with an electrolytic solution. As the electrolytic solution, physiological saline is preferable, or a mixed solution of physiological saline and alcohol may be used.

The cap 11 is provided between the fitting portion 11a formed in a cylindrical shape to be fitted to the outer surface of the tip of the electrode device body 8 and the metal electrode 9 disposed at the tip of the electrode device body 8. 10 is provided with an inner flange portion 11b sandwiching the periphery of 10 and a circular opening 11c is formed inside the inner flange portion 11b.
FIG. 4 shows a state in which the electrode device 1 in a state in which the metal electrode 9, the elastic member 10, and the cap 11 are assembled at the tip of the electrode device body 8 is brought into contact with the scalp A having the hair B. The elastic member 10 protrudes forward from the opening portion 11 c of the cap 11 to the front end surface on the inner side of the peripheral edge of the elastic member 10 crushed between the inner flange portion 11 b of the cap 11 and the metal electrode 9.

The area of the opening 11c is set to about 19 mm ² or more.
Table 1 and FIG. 5 show the measurement results of the contact resistance value in each electrode device 1 arranged in contact with the scalp A when selecting the area. The opening 11c was circular, and the contact resistance value was measured by changing the diameter of the opening 11c. Table 1 shows the contact resistance value and the average value at each measurement point, and FIG. 5 is a graph showing the relationship between the diameter dimension of the opening 11c and the average value of the contact resistance value. According to this measurement result, the contact resistance value is large when the diameter dimension of the opening 11c is smaller than 5 mm, but the average value of the contact resistance value is 5 or more, that is, when the area is about 19 mm ² or more. 10 kΩ or less.

Therefore, the contact resistance value can be kept low by setting the area of the opening 11c to about 19 mm ² or more. On the other hand, as shown in Table 1 and FIG. 5, if the diameter dimension of the opening 11c is 5 mm or more, the contact resistance value does not change much. Accordingly, it is sufficient that the area of the opening 11c is about 19 mm ² or more, and it is not necessary to make it excessively large. Since a plurality of electrode devices 1 are arranged in contact with the scalp A, it is necessary to ensure a sufficient distance from other adjacent electrode devices 1. Considering problems such as mechanical interference and electrical short circuit, the diameter of the opening 11c is preferably 20 mm or less, that is, the area of the opening 11c is preferably 314 mm ² or less.
In addition, the brain function analysis apparatus 4 receives the electroencephalogram signal S2 output from the electroencephalograph main body 7, determines the brain function state based on the electroencephalogram signal S2, and outputs the determination signal S3.

According to the electrode device 1 according to the present embodiment configured as described above, since the area of the opening 11c is set to 19 mm ² or more, the contact with the scalp A even when the hair B exists. The resistance value can be kept at a sufficiently low value, and by obtaining a stable electroencephalogram signal S2, the brain function state can be analyzed and displayed with high accuracy. Further, by setting the area of the opening 11c to 314 mm ² or less, mechanical and electrical interference with other adjacent electrode devices 1 can be avoided, and a more accurate determination of the brain function state can be performed. Can do.

  Further, in the electrode device 1 according to the present embodiment, the metal electrode 9 is made of gold or the surface of which is plated with gold, so that the resistance value of the metal electrode 9 is prevented from increasing, and the gold electrode 9 is made of gold. Due to the antirust effect, there is an effect that it is possible to prevent the resistance value from increasing with use.

Moreover, the increase in the contact resistance value can be prevented by configuring the electrolytic solution with physiological saline. Furthermore, the electrolyte solution is composed of a mixed solution of physiological saline and alcohol, so that the scalp sebum cleaning effect by alcohol can be enhanced, and an increase in contact resistance due to sebum can be prevented.
In addition, although the sponge member which can impregnate electrolyte solution was mentioned as an example as the elastic member 10, it may replace with this and may employ | adopt a nonwoven fabric. Further, the elastic member 10 and the cap 11 may be fixed integrally.

Next, an electrode device according to a second embodiment of the present invention will be described below with reference to FIG.
As shown in FIG. 6, the electrode device 20 according to the present embodiment includes a plurality of tip portions 21 that are spaced apart from each other. As in the first embodiment, the structure of each tip 21 includes a cylindrical electrode body 22, a metal electrode 23 disposed at the tip of the electrode body 22, an elastic member 24, and a cap 25. Has been. All the wirings 26 connected to the plurality of metal electrodes 23 are connected.
The total area of the openings 25a of the plurality of caps 25, that is, the elastic members 24 protruding from the openings 25a toward the distal end is 19 mm ² or more.

According to the electrode device 20 according to the present embodiment configured as described above, the total area of the elastic member 24 impregnated with the electrolytic solution is set to 19 mm ² or more. A low contact resistance value can be achieved.
Furthermore, according to the electrode device 20 according to the present embodiment, when the distal end portion 21 is brought into contact with the scalp A by arranging the plurality of distal end portions 21 at intervals, the hair B is between the distal end portions 21. It becomes easy to contact the front-end | tip part 21 with the scalp A arrange | positioned in the clearance gap and exposed between the scalp hair B which was scraped off. That is, according to the electrode device 20 according to the present embodiment, the plurality of tip portions 21 function like comb teeth and scrape the hair B, so that the scalp A comes into contact with more certainty and has a stable low contact resistance. There is an effect that the value can be achieved.

  In place of the electrode device 20 having the plurality of metal electrodes 23, the elastic member 24, and the cap 25 as in the above embodiment, the metal electrode 23 'itself has a plurality of sharp points as shown in FIGS. The structure having the tip portion 23a may be adopted, and the elastic member 24 'may be configured to cover all the tip portions 23a. According to the electrode device 20 ′ thus configured, the sharp tip portion 23 a of the metal electrode 23 ′ is inserted into the integrated elastic member 24 ′, and the elastic member 24 ′ is generated by the elasticity of the elastic member 24 ′. Is fixed by tightening the metal electrode 23 '. The plurality of tip portions 23a function like comb teeth and scrape the hair, thereby making contact between the metal electrode 23 'and the scalp A more reliable and achieving a stable low contact resistance value. be able to.

Next, an electrode device 30 according to a third embodiment of the present invention will be described below with reference to FIG.
In the electrode device 30 according to the present embodiment, as shown in FIG. 7, the metal electrode 31 is formed in a spherical shape with a radius r, and the elastic member 32 covering the metal electrode 31 also follows the shape of the metal electrode 31. It is formed in a spherical shape. The electrode main body 33, the cap 34, and the wiring 35 are the same as those in the first and second embodiments.

With this configuration, as shown in FIG. 7, the electrode device 30 cannot be disposed at a right angle to the scalp A due to the shape of the head, and is disposed at an inclination angle θ. Also, the spherical elastic member 32 can be brought into close contact with the scalp A. By setting the radius of curvature r large, the contact area between the scalp A and the elastic member 32 can be expanded to be 19 mm ² or more, and the contact resistance is the same as in the first and second embodiments. The value can be reduced.

1 is an overall configuration diagram showing a brain function analysis system including an electroencephalogram detection electrode device according to an embodiment of the present invention. It is the (a) side view, (b) front view, and (c) top view of the human head which show arrangement | positioning of the electroencephalogram detection electrode apparatus of FIG. FIG. 2 is an exploded perspective view of a tip portion of the electroencephalogram detection electrode device of FIG. 1. It is a longitudinal cross-sectional view which shows the state which made the scalp the electrode apparatus for electroencephalogram detection of FIG. 3 contacted. It is a graph which shows the relationship between the external dimension of the front-end | tip part of the electrode apparatus for electroencephalogram detection of FIG. 1, and the average value of contact resistance value. It is a perspective view which shows the front-end | tip part of the electrode apparatus for electroencephalogram detection which concerns on the 2nd Embodiment of this invention. It is a longitudinal cross-sectional view which shows the modification of the electrode apparatus for electroencephalogram detection of FIG. It is a perspective view which shows the electrode apparatus for electroencephalogram detection of FIG. It is a longitudinal cross-sectional view which shows the front-end | tip part of the electrode apparatus for electroencephalogram detection which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

A scalp B hair S2 EEG signal 1,20,20 ', 30 Electrode device (electrode device for EEG detection)
9, 23, 23 ', 31 Metal electrode 10, 24, 24', 32 Elastic member 11, 25, 34 Cap 21 Tip

Claims (7)

An electrode device for detecting an electroencephalogram that detects an electroencephalogram signal arranged in contact with a scalp having hair,
A metal electrode;
A cap having an elastic member containing an electrolyte solution disposed on the tip surface of the metal electrode;
An electrode device for detecting an electroencephalogram, wherein the area of the tip of the cap contacting the scalp is about 19 mm ² or more and about 314 mm ² or less.   The electroencephalogram detection electrode device according to claim 1, wherein the metal electrode is made of gold or plated with gold.   The electroencephalogram detection electrode device according to claim 1, wherein the electrolytic solution is made of physiological saline.   3. The electroencephalogram detection electrode device according to claim 1, wherein the electrolytic solution is a mixed solution of physiological saline and alcohol. It has a plurality of tip portions that are spaced apart from each other,
A metal electrode is arranged at the tip of each tip,
The electrode device for detecting an electroencephalogram according to any one of claims 1 to 4, wherein the total area of the cap tip surface covering all metal electrode surfaces is about 19 mm ² or more and about 314 mm ² or less. The tip of the metal electrode is formed in a substantially spherical shape,
5. The electroencephalogram detection electrode device according to claim 1, wherein the cap tip surface is formed in a substantially spherical shape along the tip of the metal electrode. An electrode device for detecting an electroencephalogram that detects an electroencephalogram signal arranged in contact with a scalp having hair,
An integral metal electrode having a plurality of tips;
A cap having an elastic member containing an electrolyte solution disposed on the tip surface of the metal electrode;
An electrode device for detecting an electroencephalogram, wherein the total area of the tip is about 19 mm ² or more and about 314 mm ² or less.

Images