KR101970696B1 - Electroencephalogram electrode and apparatus comprising the same - Google Patents

Abstract

According to an embodiment of the present invention, the EEG electrode includes a housing having a predetermined space formed therein; An electrolyte solution filled in a predetermined space of the housing; And an electrical conductor positioned inside the housing and measuring an ionic current, wherein the housing comprises a permeable membrane which is in contact with the scalp or skin and through which the electrolytic solution permeates, wherein the permeable membrane permeates only water molecules Permeable membrane or electrolytic ion is permeated, and when the permeable membrane is in contact with the scalp or skin, osmotic phenomenon is induced from the inside of the housing to the scalp or skin , An electrolyte layer is formed between the permeable membrane and the scalp or skin.

Description

ELECTROENCEPHALOGRAM ELECTRODE AND APPARATUS COMPRISING THE SAME [0002]

The present invention relates to an EEG electrode and an apparatus including the EEG electrode.

Electroencephalogram (EEG) is an electrical signal that is measured by converting ion currents generated in the brain cortex into electric current through electrical conductors during brain activity. The ion current generated by the ignition of neurons in the brain is about 1 to 2mV in size, and moves to the scalp from the cerebral cortex by the principle of electrical potential. When the ion current moves in the direction of the scalp, it is reduced to 100 μV which is one tenth of the size by the resistance inside the scalp. The ionic currents reaching the scalp are affected by the thickness of the stratum corneum, scalp oil, hair, and air.

In general, brain waves can be divided into wet electrode, dry electrode, and semi-dry electrode. The wet electrode measures the ion current related to the brain signal flowing on the scalp surface using an electrolyte gel. The core role of the electrolyte gel is to form the path of the electrolyte ion between the scalp and the electrode to assist in the movement of the ion current in the direction of the electrode. In addition, the electrolyte gel penetrates the inside of the stratum corneum and permeates the gap between the scalp and electrode, minimizing the influence of scalp oil or hair, thus lowering the impedance. Therefore, the wet electrode is capable of EEG measurement with a low impedance (5 to 15 k?) By using an electrolyte gel. However, it takes about 30 minutes to 1 hour to set up the electrolyte gel between the scalp and the electrode, and the scalp and hair are severely contaminated by the sticky electrolyte gel. In addition, when the electrolyte gel is dried about 2 hours later, EEG measurement efficiency drops.

The dry electrode is made of a highly conductive electrical conductor material without the use of an electrolyte gel to measure the EEG. Typically, a conductive polymeric material of flexible polymer is used. Advantages of dry electrodes are that they do not use electrolytic gel, so they do not require a long setup time and do not contaminate the scalp before and after use. However, dry electrode has low reliability in electroencephalography because of high contact impedance (80kΩ) caused by factors such as skin stratum corneum, air gap between scalp and electrodes, scalp oil and hair. To reduce the contact impedance, a method of applying pressure using an electrode cap to make the electrode as close as possible to the scalp is used, but it may cause pain to the scalp. In addition, when movement occurs, the electrode-scalp fixation tends to be shifted due to shaking between the scalp and the electrodes, and the measured EEG is likely to be contaminated with noise.

Semi-dry electrodes are electrodes that have been developed to solve the problems of wet electrodes and dry electrodes mentioned above. The principle of semi-conductive electrode is to store the electrolyte solution in the inside of the electrode and attach the electrode to the scalp. The electrolyte solution stored inside the electrode is inserted between the scalp and the electrode to measure the EEG. The electrolyte solution inserted between the scalp and the electrodes lowers the contact impedance and makes the path of the electrolyte ion between the electrode and the scalp, and helps the brain to be less influenced by motion noise. Compared with the electrolyte gel used in the conventional wet electrode, the electrolytic solution has a very low contamination degree of the scalp before and after use and it is possible to measure EEG with high conductivity. However, existing semi-dry electrode studies have several limitations on how to discharge the electrolyte solution.

Korean Patent Publication No. 10-2017-0051699 (entitled " Electroencephalographic Apparatus Using Dry Electrodes)

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrode which can continuously and stably provide an electrolyte solution without using an external force between the scalp and the electrode.

It is to be understood, however, that the technical scope of the present invention is not limited to the above-described technical problems, and other technical problems may exist.

According to an aspect of the present invention, there is provided an EEG electrode comprising: a housing having a predetermined space formed therein; An electrolyte solution filled in a predetermined space of the housing; And an electrical conductor positioned inside the housing and measuring an ionic current, wherein the housing comprises a permeable membrane which is in contact with the scalp or skin and through which the electrolytic solution permeates, wherein the permeable membrane permeates only water molecules Permeable membrane or electrolytic ion is permeated, and when the permeable membrane is in contact with the scalp or skin, osmotic phenomenon is induced from the inside of the housing to the scalp or skin , An electrolyte layer is formed between the permeable membrane and the scalp or skin.

According to a second aspect of the present invention, there is provided a brain wave measuring apparatus comprising: a plurality of EEG electrodes; And a processor unit for acquiring a signal transmitted from the EEG electrode and acquiring an EEG signal of the subject according to a stored algorithm.

According to the above-described task solution of the present invention, since the osmotic pressure is continuously used to provide an electrolyte solution between the scalp and the electrodes, a set-up time is hardly required for measuring brain waves, and the degree of contamination of the scalp before and after use is low, , It is possible to maintain high conductivity for a long time.

In addition, it is possible to adjust the electrode area actually touching the scalp, thereby lowering the contact impedance, and there is an effect that stable EEG measurement can be performed even when it is shaken by movement.

1 is a conceptual diagram of an EEG electrode according to an embodiment of the present invention.
2 is a view for explaining a semipermeable membrane according to an embodiment of the present invention.
3 is a view for explaining a transparent film according to an embodiment of the present invention.
4 is a conceptual diagram of an EEG electrode according to another embodiment of the present invention.
5 is a view for explaining various embodiments of a transparent film according to an embodiment of the present invention.
6 is an algorithm for adjusting the diffusion rate of the osmotic phenomenon of the EEG electrode according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. It should be understood, however, that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, the same reference numbers are used throughout the specification to refer to the same or like parts.

Throughout this specification, when a part is referred to as being "connected" to another part, it is not limited to a case where it is "directly connected" but also includes the case where it is "electrically connected" do.

Throughout this specification, when a member is " on " another member, it includes not only when the member is in contact with the other member, but also when there is another member between the two members.

Throughout this specification, when an element is referred to as " including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise. The terms " about ", " substantially ", etc. used to the extent that they are used throughout the specification are intended to be taken to mean the approximation of the manufacturing and material tolerances inherent in the stated sense, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure. The word " step (or step) " or " step " used to the extent that it is used throughout the specification does not mean " step for.

The present invention relates to an EEG electrode 10 and an apparatus including the same.

FIG. 1 is a conceptual diagram of an EEG electrode 10 according to an embodiment of the present invention. FIG. 2 is a view for explaining a semipermeable membrane 111 according to an embodiment of the present invention. FIG. 4 is a conceptual diagram of an EEG electrode according to another embodiment of the present invention, and FIG. 5 is a cross-sectional view of a permeable membrane 110 according to an embodiment of the present invention. FIG. 6 is an algorithm for adjusting the diffusion rate of the osmotic phenomenon of the EEG electrode according to an embodiment of the present invention. Referring to FIG.

Hereinafter, the EEG electrode 10 according to one embodiment of the present invention will be described.

The EEG electrode 10 has a housing 100 in which a predetermined space is formed and a predetermined space is filled with an electrolyte solution 11 and an electric conductor 200).

In addition, the housing 100 includes a permeable membrane 110 which is in contact with the scalp and through which the electrolyte solution 11 permeates due to osmotic phenomena.

The principle of osmosis phenomenon is that a low concentration solvent spontaneously moves through a membrane in the direction of a high concentration solution, and it is a natural law to balance the concentration between the two solutions by themselves. When the osmotic phenomenon is applied to the EEG electrode 10, the electrolyte solution 11 stored in the housing 100 can be smoothly moved in the scalp direction without using external energy.

The permeable membrane 110 may be made of a material such as a cellulosic membrane, a noncellulosic membrane, a nonacetic acid cellulose membrane, or the like, which is flexible and can be adhered to the scalp of the curved surface.

Also, the transmissive film 110 has a thickness of about 100 micrometers or less, and can be made to have a sufficiently thin thickness with a minimum mechanical strength. In addition, the electrolyte solution 11 contains electrolyte ions such as sodium and chlorine, and the concentration may be more than 0% and less than 0.9%. In other words, when the concentration of the electrolyte solution 11 in the EEG electrode 10 is set to more than 0% and less than 0.9%, the salinity concentration in the scalp is generally 6% Or an osmotic phenomenon may be induced in the skin, and an electrolyte layer may be formed between the permeable membrane 110 and the scalp or skin.

The transmissive film 110 may be a transmissive film 111 through which only water molecules can permeate or a transmissive film 112 in which a plurality of fine holes 112a through which water molecules bonded with electrolyte ions are formed are formed.

2, when the permeable membrane 110 is permeable to only water molecules and water molecules combined with electrolyte ions are formed of a permeable membrane 111 that can not permeate, the stratum corneum of the scalp, And water ions in the electrolyte solution 11 permeate through the permeable membrane 110 due to the osmotic phenomenon due to the saline ions present in the hair follicle. At this time, the water molecules bound to the electrolyte ion are not transmitted. The permeated water molecules penetrate into the stratum corneum, the sweat glands and the hair follicles of the scalp and bind to the saline ions, and the saline ions combined with the water molecules can not pass through the semipermeable membrane 111 and adhere to the surface of the semipermeable membrane 111 , And an electrolyte layer can be formed between the scalp and the EEG electrode 10. At this time, the ion current related to the brain signal moves to the EEG electrode 10 through the electrolyte layer, and the electric conductor 200 can measure the ion current.

3, when the permeable membrane 110 is a membrane and a membrane 112 in which a plurality of microholes 112a through which water molecules combined with electrolyte ions are formed is formed, water molecules combined with electrolytic ions pass through the permeable membrane 110, The electroencephalogram measurement electrode 10 may be moved through the plurality of fine holes 112a formed in the scalp and the EEG electrode 10 to form an electrolyte layer. At this time, the ion current related to the brain signal moves to the EEG electrode 10 through the electrolyte layer, and the electric conductor 200 can measure the ion current.

In addition, the EEG electrode 10 can efficiently measure EEG using the permeable membrane 110 having an optimal osmotic development rate. A detailed description thereof will be given later.

Hereinafter, a housing 100 according to an embodiment of the present invention will be described in detail with reference to FIG.

The housing 100 may further include an outer receiving portion 120 formed in a ring shape and a lid 130 covering an upper portion of the outer receiving portion 120,

The external receiving unit 120 can maintain the basic shape of the EEG electrode 10 and move the ion current related to the minute brain signal flowing into the surface of the hair into the EEG electrode 10. Therefore, the external receiving unit 120 preferably uses a conductive polymer material or a conductive metal material.

The permeable membrane 110 is replaceably installed in the external receiving unit 120 and can be replaced with a new permeable membrane 110 when the membrane is damaged or the microhole 112a is clogged.

The lid part 130 is made of a non-conductive material, and can fix the position of the electrical conductor 200.

The cap 130 may further include an injection port 131 through which the electrolyte solution 11 can be replenished and the housing 100 may further include a cap 140 blocking the injection port 131. [ In other words, when the electrolyte solution 11 needs to be replenished, the injection port 131 can be opened to supply the electrolyte solution 11 into the interior of the housing 100. Thereby, the EEG electrode 10 can be used semi-permanently.

The housing 100 is manufactured to have a width of 1.5 cm or less and a height of 2.5 cm or less so that 200 to 600 uL of the electrolyte solution 11 can be stored therein. In addition, the electroencephalogram phenomenon progresses at a rate of 10 to 20 uL / h in the EEG electrode 10, and the osmotic phenomenon can proceed for a minimum of 20 hours to a maximum of 60 hours.

Hereinafter, an electric conductor 200 according to an embodiment of the present invention will be described with reference to FIG.

The electrical conductor 200 has an end located within the housing 100 and is capable of measuring ion currents associated with brain signals flowing through the scalp or hair. For this purpose, the electrical conductor 200 may be a conductive material using at least one of Ag, AgCl, Cu, Au, and Ti, but is not limited thereto.

Further, the end portion of the electric conductor 200 can be designed in the shape of a concave square as shown in Fig. Since the shape of the concave quadrangle is larger than that of the other types of surface, electrolyte ions are bonded to the surface, and the ion current can be efficiently measured. The above-mentioned concave square may mean a square shape in which a vertex of a rectangle is recessed inward to have a predetermined curvature.

In addition, the electrical conductor 200 may have a width less than a half of the width of the housing 100, so that movement of the particles inside the electrolyte solution 11 is not disturbed.

The end of the electrical conductor 200 is located between 1/2 to 1/3 of the height of the housing 100 and is not affected by the reduction of the electrolyte solution 11 in the housing 100 by the osmosis phenomenon desirable. In other words, when the end portion of the electric conductor 200 is located at a position of 1/2 or more, as the electrolyte solution 11 is gradually moved to the outside, the end portion of the electric conductor 200 is not immersed in the electrolyte solution 11 If the height is less than 1/3 of the height of the permeable membrane 110, the permeable membrane 110 may be damaged and damage the permeable membrane 110.

Hereinafter, an EEG electrode 10 according to another embodiment of the present invention will be described with reference to FIG.

The EEG electrode 10 according to another embodiment of the present invention can be manufactured in the shape of an ellipse in cross section of the housing 100. Illustratively, the housing 100 may be formed in the form of a rugby ball and may be inserted into the ear of a user.

The housing 100 may include a lid 130 located at one side of the major axis of the ellipse and an external receiving unit 120 located at the other side of the major axis of the ellipse and being a conductive polymer or a conductive solid material.

In addition, the transmissive film 110 may have an elliptical cross section, one side edge may be fixed to the periphery of the lid part 130, and the other side edge may be fixed to the periphery of the external receiving part 120.

The EEG electrode 10 may further include a signal conversion unit 150 for converting an electrical signal from the electrical conductor into a digital signal.

The EEG electrode 10 may further include a signal transmission unit 210 for connecting the electrical conductor 200, the signal conversion unit 150, and the external reception unit 120 to each other. The signal transmission unit 210 not only transmits the electrical signals of the electrical conductor 200 and the external reception unit 120 to the signal conversion unit 150 but also supports the electrical conductor 200 and the external reception unit 120, 100).

When the thus formed EEG electrode 10 is inserted into the ear canal of the ear, a part or the whole of the permeable membrane 110 is kept in contact with the ear canal wall of the ear, and the ear canal is formed between the ear canal of the ear and the permeable membrane 110 EEG can be performed through the electrolyte layer.

Hereinafter, with reference to FIG. 5, various embodiments of the transparent film 110 according to an embodiment of the present invention will be described.

As shown in Fig. 5A, the transmissive film 110 may be formed to have a flat outer surface or a plurality of protrusions whose outer surface is wrinkled, as shown in Fig. 5 (b) . Further, the transmissive film 110 may include a plurality of fin portions protruding from the outer surface, as shown in Fig. 5 (c). In other words, since the amount of hair varies depending on the attachment position of the scalp or the skin, the shape of the permeable membrane 110 may be selected to attach the EEG electrode 10 to control the rate of the osmotic phenomenon.

The apparatus for measuring EEG according to an embodiment of the present invention includes a processor unit for collecting signals transmitted from a plurality of electrodes 10 and an EEG electrode 10 and acquiring an EEG signal of the subject according to a stored algorithm.

Hereinafter, an algorithm for adjusting the diffusion rate of the osmotic phenomenon of the EEG electrode 10 according to an embodiment of the present invention will be described.

The main feature of the present invention is to select the concentration of the permeable membrane 110 and the electrolyte solution 11 according to the thickness of the horny layer of the scalp of the user and the amount of hair on the scalp or skin, I will.

First, the occurrence time of the osmotic phenomenon is inversely proportional to the thickness of the transmembrane membrane 110 and the horny layer of the scalp, and the difference between the temperature and the diffusion speed and concentration of the molecules, The size of the contact area, the size of the hole in the permeable membrane 110, and the number of holes. In other words, in order to induce the osmosis phenomenon in a short time between the scalp and the EEG electrode 10, it can be adjusted through the above-mentioned proportional factors.

The amount of the electrolyte solution 11 inserted between the scalp and the EEG electrode 10 per unit time, that is, the diffusion rate of the osmotic phenomenon, is calculated by the following equation (2) Is in inverse proportion to the thickness of the transmissive film 110, in proportion to the actual contact area of the transmissive film 10, the size of the hole in the transmissive film 110, and the number of holes in the transmissive film 110. Therefore, it is possible to adjust through the above-mentioned proportional factors to insert an appropriate amount of the electrolyte solution 11 between the scalp and the EEG electrode 10.

In other words, referring to FIG. 6, the osmotic development rate of the electrolytic solution can be changed by adjusting the thickness and shape of the permeable membrane 110 and the concentration of the electrolytic solution 11, which are factors related to the osmotic development rate.

In detail, the shape and thickness of the permeable membrane 110 can be selected according to the thickness of the user's horny layer of scalp and the amount of hair on the scalp or skin. Illustratively, the thickness of the permeable membrane 110 may be less than 100 μm, such as 90 μm, 80 μm, 70 μm, etc., and may be selected and used by the user depending on the thickness of the horny layer. In addition, since the contact area of the permeable membrane 110 varies depending on the amount of hair on the scalp or skin, the osmotic pressure rate desired by the user can be selected by selecting the permeable membrane 110 having a different form.

Further, the user can select the concentration of the electrolytic solution 11 between 0% and less than 0.9% to adjust the osmotic pressure rate. Illustratively, the electrolyte solution 11 having a concentration of 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7% and 0.8% .

6, the user determines the concentration of the electrolytic solution 11 according to the thickness of skin or scalp hair to which the EEG electrode 10 is attached, the thickness of the horny side of the scalp, the permeability of the permeable membrane 110 And the thickness of the permeable membrane 110 can be selected to have the optimum osmotic development rate.

 Referring to Equation (3), the progress time of the osmotic phenomenon is proportional to the electrolyte storage capacity of the housing 100 and inversely proportional to the amount of the electrolyte solution 11 inserted between the scalp and the EEG electrode 10 . Therefore, in order to increase the use time of the semi-edible electrode 10, it is possible to control by increasing the electrolyte storage capacity and slowing the osmosis phenomenon.

It will be understood by those of ordinary skill in the art that the foregoing description of the embodiments is for illustrative purposes and that those skilled in the art can easily modify the invention without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

10: Electroencephalogram measurement electrode 11: Electrolyte solution
100: Housing
110: Transmission film 120: External receiving section
130: lid part 131: inlet
140: Plug
150: Signal conversion section
200: electric conductor
210:

Claims (18)

In the EEG electrode,
A housing having a predetermined space formed therein;
An electrolyte solution filled in a predetermined space of the housing; And
An electric conductor located inside the housing and measuring an ion current,
The housing
A permeable membrane which is in contact with the scalp or skin and through which the electrolyte solution is permeated by osmotic phenomenon,
The permeable membrane
Permeable film through which water molecules are permeated, or a plurality of fine holes through which water molecules bonded with electrolyte ions are permeated,
Wherein an osmotic phenomenon is induced from the inside of the housing to the scalp or skin when the permeable membrane contacts the scalp or skin, and an electrolyte layer is formed between the permeable membrane and the scalp or skin.
The method according to claim 1,
Wherein the osmotic pressure rate of the electrolyte solution is changed according to the shape and thickness of the permeable membrane and the concentration of the electrolyte solution.
The method according to claim 1,
Wherein the concentration of the electrolyte solution is more than 0% and less than 0.9%.
The method according to claim 1,
The housing
An external receiving unit located on the upper side of the permeable membrane and formed in a ring shape and being a conductive polymer or a conductive solid material; And
And a lid portion covering the upper portion of the external receiving portion.
5. The method of claim 4,
The cover
And an injection port capable of replenishing the electrolyte solution is formed.
6. The method of claim 5,
And the lid part is formed of a non-conductive material.
The method according to claim 1,
The housing has an elliptical cross section,
A lid part located at one side of the major axis of the ellipse; And
And an external receiving portion which is located on the other side of the major axis of the ellipse and is a conductive polymer or a conductive solid material,
The permeable membrane
Wherein one end edge is fixed to the peripheral portion of the lid portion and the other edge is fixed to the peripheral portion of the external receiving portion.
8. The method of claim 7,
Further comprising a signal transmission unit for connecting the electrical conductor, the signal conversion unit, and the external reception unit to each other.
The method according to claim 1,
The permeable membrane
Wherein the electroencephalogram electrode comprises a plurality of protuberances formed on the outer surface.
The method according to claim 1,
The permeable membrane
And a plurality of pin portions protruding from the outer surface.
The method according to claim 1,
Wherein the permeable membrane is one of a cellulosic film, a noncellulosic film, and a nonacetic cellulose film.
The method according to claim 1,
Wherein the permeable membrane is provided to be replaceable.
The method according to claim 1,
Wherein the electric conductor includes at least one of Ag, AgCl, Cu, Au, and Ti having high conductivity.
The method according to claim 1,
Wherein the electric conductor has an end concave like shape.
The method according to claim 1,
Wherein an end portion of the electric conductor is located between 1/2 and 1/3 of the height of the housing.
The method according to claim 1,
The housing
Wherein an electrolyte solution of 200ul to 600ul can be stored therein.
The method according to claim 1,
Further comprising: a signal converting unit for converting an electrical signal from the electrical conductor into a digital signal.
In an EEG instrument,
A plurality of EEG electrodes according to any one of claims 1 to 17; And
And a processor unit for collecting signals transmitted from the EEG electrodes and acquiring EEG signals of the subject according to a stored algorithm.

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