JP2020195777A - Brain activity measurement electrode, head-mounted device comprising the electrode, and brain activity measurement system - Google Patents

Abstract

To provide a brain activity measurement electrode, a head-mounted device using the electrode, and a brain activity measurement system, the electrode easily made to abut on a subject's scalp so that the electrode faces the scalp regardless of the subject's head shape in the case of being used together with means for fixing the electrode, for example, an electroencephalographic cap, a head set, or the like, the electrode enabling easy measurement when the measurement is hardly performed because of dry type measurement.SOLUTION: A brain activity measurement electrode 5 to be used so as to be made to abut on a scalp includes: a plurality of scalp grounding parts having a function of acquiring electric information when the parts are made to abut on the scalp; a plurality of guide bodies arranged around the scalp grounding parts; a wet electrode mounting part; and a wet member that is demountably mounted on the electrode mounting part. Thereby, the electrode is made to be used as a wet electrode when the wet member is mounted on the wet electrode mounting part, and is made to be used as a dry electrode when the wet member is removed from the wet electrode mounting part.SELECTED DRAWING: Figure 1

Description

The present invention relates to electrodes for measuring brain activity used for measuring brain activity, a head-mounted device provided with the electrodes, and a brain activity measuring system.

In EEG measurement, there are wet type and dry type as a method of placing electrodes on the head of the subject. In the wet type, for example, the hair at the electrode attachment point is scraped off to expose the scalp, and if necessary, sebum on the scalp is removed with alcohol or the like, and an electrode such as a dish electrode coated with a conductive gel or a conductive paste. Is grounded to the scalp. In this case, since the contact resistance can be lowered, even a passive electroencephalograph can acquire an electroencephalogram with less noise contamination. However, since it is necessary to remove sebum with alcohol or apply conductive gel or conductive paste to the subject's head when measuring brain waves, it is quite popular except for precise brain wave measurement in research and medical applications. Not. Further, in the passive electroencephalograph, there is a problem that the electrode wire connecting the electrode to the differential amplifier (amplifier) becomes a noise source when the subject touches or moves, and it is particularly difficult to measure the brain activity accompanied by the movement.
For this reason, various dry electrodes have been developed. The dry type electrode uses a metal, a conductive resin, or the like. Unlike the wet type electrode, it is not essential to apply a conductive gel or a conductive paste to the head of the subject, or to remove sebum with alcohol or the like before touching down the dry type electrode. Therefore, it is expected not only for research and medical purposes but also for industrial applications such as healthcare. In the dry type electrode, the contact resistance does not decrease as compared with the case where the wet type electrode is placed by using a conductive paste or the like, so that noises derived from the environment or the like are likely to be mixed in the brain waves. Therefore, the dry electrode is usually used in combination with an active electrode in which a preamplifier is arranged in the vicinity of the electrode. In the active electrode, the preamplifier suppresses the generation of noise from the electrode wire that connects the electrode and the differential amplifier (amplifier), and even when the subject is moving, measurement of brain waves with less noise from the electrode wire Becomes possible. The dry type electrode is called a dry electrode, and the wet type electrode is called a wet electrode.

Unlike the wet type electrode, it is not essential to apply a conductive gel or a conductive paste to the subject's head, or to remove sebum with alcohol or the like before touching down the dry type electrode. However, on the other hand, since the dry electrode is not placed on the scalp via a conductive paste or the like, it is used together with a means such as an electroencephalogram cap or a headset for fixing some electrode to the subject's head and grounding it. There is a need. Further, in the dry type electrode, since the electrode is not placed on the scalp via a conductive paste or the like, it is necessary to devise an electrode shape so that hair can be prevented from being caught between the electrode and the scalp and electricity can be supplied. .. The dry type electrode can accurately record the waveform of the brain wave even if the contact resistance is relatively high by combining it with the active electrode. Due to the influence of the environment, the contact resistance hardly decreases, and it may not be possible to record brain waves with sufficient accuracy.

Patent Document 1 is shown as an example of a dry electrode. Patent Document 1 relates to a resin electrode exhibiting conductivity, a head-mounted device using the electrode, and a brain activity measurement system. For example, a large number of columnar protrusions on a disk 138 as shown in FIG. 31. An electrode having 139 is disclosed.

JP-A-2017-202289

An electrode having "a large number of columnar protrusions (scalp grounding portion)" as in Patent Document 1 has the following problems when used together with means for fixing electrodes such as an electroencephalogram cap and a headset.
First, as shown in FIG. 16A, such an electrode is designed on the assumption that "a large number of columnar protrusions" face the scalp as a whole and come into contact with the ground. The electrode center line is perpendicular to the plane direction of the scalp. The "many columnar protrusions" avoid intervening hair and increase the likelihood that some of the electrodes will come into contact with the scalp and disperse the force from the electrodes on the scalp. However, according to the study by the inventors, when this electrode is used as a means for fixing an electrode such as an electroencephalogram cap or a headset, as shown in FIG. 16 (b), only one of the protrusions or two adjacent electrodes are on the scalp. In contact with the electrodes, other protrusions float and the force applied to the electrodes is balanced, which occurs at a considerable rate.
When the electrodes are grounded with a cloth or net like an electroencephalogram cap, the orientation of each electrode should be checked and corrected, but it takes time and effort to adjust each electrode. Occasionally, as shown in FIG. 16B, the electrodes may not be noticed in a floating state. Further, especially in the case of a headset, since the degree of freedom in adjusting the orientation of the electrodes is inferior to that of the brain wave cap, it may be difficult to correct the orientation of the electrodes as shown in FIG. 16 (b). is there. In that case, the waveform of the brain wave itself can be measured because the tip of the columnar protrusion is in contact with the scalp. However, since all the force that presses the electrode against the scalp as shown by the broken line is applied to the tip of the columnar protrusion that is in contact with the scalp, the subject may be in pain. According to the studies by the inventors, the electrode positions that are likely to be balanced in the state shown in FIG. 16B are, in particular, the frontal, midline frontal, and the midline frontal shown in FIG. It is an electrode centered on the electrodes of the parietal and midline parietal. This is because these electrode positions are such that the electrodes are easily grounded to the scalp from an angle (that is, from a certain point), the difference in the shape of the head of an individual is large, and the angle at which the electrodes are grounded varies.
Normally, in order to improve the problem of electrode orientation during mounting, the first solution is to devise the operating mechanism of the electrode holding part such as a headset, but by devising the electrode itself, it is applied to the scalp. On the other hand, it is even better if it can be made difficult to be grounded diagonally.
As described above, as a problem of the dry type electrode as shown in Patent Document 1, when it is used together with a means for fixing an electrode such as an electroencephalogram cap or a headset, how can it be worn without trouble? The question is whether to make it difficult to touch the ground diagonally to the scalp.
Further, as another problem of the dry type electrode as shown in Patent Document 1, in the dry type electrode, the contact resistance is hardly reduced due to the skin type and constitution of the scalp of the person to be measured by the electroencephalogram. It can be mentioned that even the same subject may not be able to measure with sufficient accuracy because the contact resistance hardly decreases due to the environment such as room temperature and humidity. Compared to wet electrodes, dry electrodes have potential for purposes other than research and medical applications such as healthcare applications, but they cannot always be measured in all cases and can be measured by simple means as needed. A dry electrode having a measurable recovery means is desired.
In view of these problems, when used together with means for fixing electrodes such as an electroencephalogram cap and a headset, the present invention tends to cause the electrodes to face the scalp regardless of the head shape of the subject. Moreover, the present invention provides an electrode for measuring brain activity having a recovery means that enables easy measurement when it is difficult to measure by a dry type, a head wearing device equipped with the electrode, and a brain activity measuring system.

In order to solve the above problems, in the first means, one or a plurality of scalp grounding portions having a function of contacting the scalp to acquire electrical information and one or a plurality of scalp grounding portions arranged around the scalp grounding portion. The wet electrode mounting portion formed in the inner region of the plurality of scalp grounding portions or shared with at least one of the scalp grounding portions, and the wet electrode mounting portion that can be attached to and detached from the wet electrode mounting portion. The member is provided, and is used as a wet electrode when the wet member is mounted on the wet electrode mounting portion, and is used as a dry electrode when the wet member is removed from the wet electrode mounting portion. did.
When the electrode for measuring brain activity is tilted by the "guide body" and tries to come into contact with the scalp, one of the tips of the guide body outside the scalp ground contact portion comes into contact with the scalp first, and the brain activity. When the measurement electrode is fixed to the head mounting device and used, the brain activity measurement electrode is grounded to the scalp with the tip of any of the guide bodies previously grounded to the scalp as a fulcrum. At this time, as compared with the case where one of the tips of the scalp grounding portion does not have the guide body and touches the scalp first, by having the guide body, the tip of any of the guide bodies from the electrode center line When the electrodes for measuring brain activity are in contact with the scalp at an angle, a moment is likely to be generated. Therefore, it is unlikely that the electrode for measuring brain activity will be in an oblique state and will be grounded to the scalp only at the tip of a part of the grounding part of the scalp, and the electrode for measuring brain activity will be easily grounded facing the scalp. .. As shown in FIG. 16A, the electrode center line is a line perpendicular to the scalp at the electrode center position when the electrode for measuring brain activity faces the scalp.
By attaching or detaching the "wet member" to the "wet electrode mounting portion", the electrode for measuring brain activity can be used as both a wet electrode and a dry electrode. This electrode for measuring brain activity becomes a wet electrode when the wet member is attached to the wet electrode mounting portion, and becomes a dry electrode when the wet member is removed from the wet electrode mounting portion. Therefore, whether to use the wet electrode or the dry electrode is selected. It can be easily selected.
The "wet electrode mounting portion" is formed in the inner region of a plurality of scalp ground contact portions, or at least one of the scalp ground contact portions can be shared as the wet electrode mounting portion. When forming in the inner region of a plurality of scalp grounding portions, the scalp grounding portion exists around (outside) the wet electrode mounting portion, and when the brain activity measurement electrode is brought into contact with the scalp, the scalp grounding is first performed. The part will come into contact with the scalp. Therefore, the presence of the wet electrode mounting portion when the wet member is attached to and detached from the brain activity measuring electrode does not prevent the scalp grounding portion from coming into contact with the scalp. Further, when the wet member is attached and used, the wet member also tends to come into contact with the scalp when the scalp ground contact portion comes into contact with the scalp. In addition, the shape of the scalp grounding portion and the shape of the wet electrode mounting portion can be made independent and the structure can be designed for each function. On the other hand, when at least one of the scalp grounding portions can be shared as the wet electrode mounting portion, the scalp grounding portion should come into contact with the scalp as the scalp grounding portion when the wet member is detached and used. Further, when the wet member is attached and used, the scalp grounding portion becomes a wet electrode attaching portion for fixing the wet member to the electrode for measuring brain activity. This scalp grounding portion is a scalp grounding portion that can also serve as a wet electrode mounting portion, and even if the shape is the same, the scalp grounding portion and the wet electrode mounting portion 2 can be used depending on whether the wet member is attached or removed. Will have two roles. By having two roles in this way, the structure of the electrode for measuring brain activity can be simplified. The scalp grounding portion that can also serve as the wet electrode may be formed in the inner region of the plurality of scalp grounding portions, and regardless of the medial region, at least one of the plurality of scalp grounding portions may be formed with the wet electrode. Although it may be a scalp grounding portion that can also serve as a wet electrode, it is more preferable that the scalp grounding portion that can also serve as a wet electrode is formed in the inner region of a plurality of scalp grounding portions.
The dry electrode can function as a wet electrode by attaching a wet member. For example, the outer scalp grounding portion can be used as a dry electrode, and an electrode having both a dry type and a wet type can be provided together with the inner wet electrode. This is especially suitable when the brain activity is an electroencephalogram. In the case of dry electrodes in EEG measurement, it may be difficult for the contact resistance to decrease depending on the subject's constitution, temperature, humidity, etc., but by forming a wet electrode mounting part, the dry electrodes can be wetted as necessary. By combining electrodes, it becomes possible to acquire brain wave waveforms with less noise regardless of the subject, temperature, and humidity.
The "wet member" is a fiber bundle, a fiber mass, a gel-like substance, or the like, which is configured to hold (contain) a substance containing ions such as a physiological saline solution, a conductive aqueous solution, or a conductive gel. The wet member is for assisting the conductivity of the dry electrode or changing the dry electrode to a wet electrode. The tip of the wet member should have at least one positive curvature, and the tapered tip should be shaped to avoid hair and easily contact the scalp. It is preferable that the wet member has flexibility because it is easily held when it is mounted on the wet electrode mounting portion. The thickness (height direction) of the wet member is not particularly limited, and may be 1 mm or less like a sheet. Further, particularly when the thickness is about 2 mm to 8 mm, it is preferable because it is easy to handle the wet electrode mounting portion by attaching or detaching it.
When the electrode is grounded to the scalp, the "electrode for measuring brain activity" may be fixed to the head by a head wearing device such as an electroencephalogram cap, a headset, or a headband. The headset has a mechanism / structure for fixing the electrodes for measuring brain activity to the head, and includes a composite shape combined with a device such as eyeglasses, headphones, or a VR display. Both dry and wet electrodes can be used for the scalp grounding part, but dry electrodes that can measure brain activity without using conductive paste for brain wave measurement, conductive gel, cotton impregnated with physiological saline, etc. It may be an electrode.
The shape of the "guide body" is not particularly limited. The number of guide bodies may be one or more. The tip of the guide body is preferably convex because it serves as a fulcrum when the electrode is in contact with the scalp. By making the protrusions, it is possible to avoid hair and reduce the floating of the electrodes when they are brought into direct contact with each other. This protrusion may be conical or columnar, but by making it an "elliptical frustum" or "plane" with a width of about 2.5 to 5 mm, the ground contact shape when the guide body comes into contact with the scalp can be changed from a "point". It is even better because it can be made into a "line" and the pressure on the scalp can be reduced. By reducing the pressure applied to the scalp, it is possible to reduce the pain and oppressive feeling when the wearer wears the electrodes for measuring brain activity. The guide body may be around the scalp ground contact portion, and the outermost scalp ground contact portion may also serve as the guide body. When the outermost scalp grounding part also serves as a guide body, when the brain activity measuring electrode is tilted and tries to come into contact with the scalp when the brain activity measuring electrode is attached, the outermost scalp grounding part is used. One of the tips of the guide body that also serves as the scalp first touches the scalp, and the tip of one of the guide bodies that first touches the scalp serves as a fulcrum, and the electrodes for measuring brain activity face the scalp and touch the ground. .. After the electrodes for measuring brain activity touch the scalp, the guide body serves as a grounding part for the scalp. When the guide body is a guide body that also serves as a ground contact portion for the scalp, it is preferable that the guide body is made of a conductive material so that brain activity can be acquired. When the guide body is a guide body that also serves as a scalp ground contact portion, the ground contact diameter of the scalp ground contact portion to the scalp, that is, the ground contact diameter of the outermost guide body is preferably φ6 to 15 mm. If it is too narrow, the possibility of contact between the scalp and the electrodes will decrease, and if it is too wide, the area where brain activity will be acquired will expand, and the measured brain activity will deteriorate.
If the guide body is not a guide body that also serves as a scalp ground contact portion, and the guide body and the scalp ground contact portion are different, for example, the guide body uses a non-conductive material or is between the electrodes for measuring brain activity. It is preferable that the insulator is arranged so as to be insulated. This is because the brain activity can be recorded with high accuracy by eliminating the mixing of the brain activity from the guide body.
The guide body may or may not also serve as the scalp ground contact portion, and the guide body should be flexible. This is because the bending force reduces the pressing force on the scalp when it touches the scalp. Here, when the flexibility of the guide body is a material having low flexibility (hard to deform) of the scalp ground contact portion or almost the same flexibility, the tip of the guide body is the tip of the scalp ground contact portion. It should be on the same plane as the above, or at a position about 0.5 to 1 mm away from the scalp from the tip of the scalp grounding portion. This is because it is necessary to ground the scalp grounding portion to the scalp in order to measure the brain activity, but if the scalp grounding portion protrudes too much, it will not function as a guide body. Further, when the flexibility of the guide body is significantly larger than the flexibility of the scalp ground contact portion (easily deformed), the tip of the guide body should be longer toward the scalp side than the flat surface of the tip of the scalp ground contact portion. Good. In that case, the bending of the guide body makes it easier for the electrodes to face the scalp. If the guide body is not a guide body that also serves as a scalp grounding part, the grounding diameter of the scalp grounding part to the scalp should be φ6 to 15 mm, and the outermost diameter of the guide body is larger than the grounding diameter of the scalp grounding part to the scalp. The radius should be 3 mm to 5 mm larger. If the contact diameter of the scalp grounding part to the scalp is too narrow, the possibility of contact between the scalp and the electrodes decreases, and if it is too wide, the area where brain activity is acquired expands and the measured brain activity deteriorates. It becomes.
The shape of the "scalp grounding part" does not matter. Multiple scalp grounding parts are preferable. The scalp grounding part should have conductive performance because it acquires brain activity as electrical information. It may be a metal, but it may also be a synthetic resin material having conductive performance.

Here, "brain activity" can generally be measured as a magnetic field generated by the flow of an electric current from the outside, a potential difference (voltage difference) at different positions, and a difference in the amount of near-infrared light due to absorption of oxygenated hemoglobin, deoxidized hemoglobin, etc. Therefore, the "electrode for measuring brain activity" of the present invention includes, for example, an electrode for measuring electroencephalogram that measures a change in current (change in potential difference) associated with nerve activity in the brain, and a change in magnetic field that changes in current accompanying brain activity. Electrodes for measuring electroencephalogram (electroencephalography) and changes in cerebral blood flow (oxygenated hemoglobin, deoxidized hemoglobin amount, etc.) associated with brain activity are measured as changes in the amount of near-infrared light received. It is often used as a probe for magnetoencephalography. In particular, when recording brain activity as a potential difference (voltage difference) (electroencephalogram measurement), a dry electrode is preferable because it can reduce the measurement burden on the subject. The brain activity may be an electroencephalogram recorded as a potential difference (voltage difference). Further, the brain activity is preferably a brain magnetic field recorded as a change in the magnetic field. These brain activities measure the neuron activity associated with nerve activity in milliseconds, and by grounding the electrodes for measuring brain activity directly to the scalp, it is possible to record brain activity with high accuracy. This is to become.
Here, "contact with the scalp" means brain activity so that when measuring brain activity using electrodes for measuring brain activity, the brain activity can be acquired as data such as potential difference, magnetic field change, and amount of received near infrared rays. The measurement electrode is in contact with or in close proximity to the scalp. It is preferable that the electrodes for measuring brain activity are in close contact with the scalp, but it is not always necessary, and if the brain activity can be obtained as data, even if the electrodes are slightly separated from the scalp or the hair is sandwiched between them. I do not care.
These definitions are the same for the following means.

Further, as a second means, the wet electrode mounting portion has a protruding portion, the wet member is composed of a fiber bundle, and the wet member is pierced and held in the protruding portion.
Since the protruding part is pierced by the wet member composed of fiber bundles, it is easy to attach and remove, and once pierced by the protruding part, the wet electrode supports the protruding part from the surroundings. Since it is difficult to pull out from the protruding portion, having the protruding portion may be a means for holding the wet electrode made of a fiber bundle. By doing so, the wet electrode mounting portion can be held with a strong force, so that the wet member does not fall off when the electrode is grounded to the scalp of the subject. The wet member may or may not be in contact with the side surface of the scalp ground contact portion. When it comes into contact with the side surface of the scalp grounding portion, the stability when holding the wet member is increased. On the other hand, when the wet member is held without touching the side surface of the scalp ground contact portion, the wet member can easily serve as a cushion. Such holding is possible by piercing and holding a wet member composed of a fiber bundle in the protruding portion. It is easy for the wet member to hold the protruding part if it is a truncated cone with a tip diameter of about φ0.5 to 1 mm or an elliptical frustum with a tip diameter in the longitudinal direction of about 0.5 to 1.5 mm. Even when the wet electrode mounting portion also serves as the scalp grounding portion, it is preferable because the wearing feeling when mounted on the scalp is improved.
The fiber material of the wet member made of the fiber bundle is not particularly limited as long as it is a material capable of forming the fiber bundle. Natural fibers such as vegetable fibers and animal fibers, chemical fibers such as inorganic fibers, purified fibers, regenerated fibers, semi-synthetic fibers, and synthetic fibers can be used. The vegetable fibers are cotton, cabock, hemp (linen), hemp, jute, sisal, palm, rush and the like. Animal fibers include silk, wool, alpaca, angora, cashmere, camel, mohair, camel, down, feather and the like. The inorganic fiber is a glass fiber, a carbon fiber, a ceramic fiber, a metal fiber or the like. The refined fiber is lyocell, tencel or the like. The regenerated fiber is rayon, viscose rayon, polynosic, cupra, regenerated cellulose fiber or the like. The semi-synthetic fiber is acetate, triacetate, promix or the like. Synthetic fibers include nylon, polyester, acrylic, acrylic, vinylon, polypropylene, polyvinyl chloride, polyurethane, polyethylene, vinylidene, aramid, polyarylate, PBO, ethylene vinyl alcohol, acrylate, polylactic acid and the like. The fiber bundle can be formed, for example, by extruding or extending in a columnar shape. A fiber material having water absorption or a fiber material having non-water absorption may be used, but the non-water-absorbing material is preferable because it is not sticky. It is preferable that the fiber bundle is formed into a columnar fiber bundle, and the tip of the fiber bundle is chamfered using a mold or the like or has an R shape. By thinning the tip of the fiber bundle, it becomes easier to avoid hair. The diameter of the fiber bundle is preferably about φ4 to 10 mm. The wet member may be impregnated with physiological saline or a conductive gel. It is particularly preferable to use physiological saline to soak the wet member because it is not necessary to wash the hair after measurement. By keeping the wet member as a fiber bundle, the physiological saline or the conductive gel can easily permeate into the fiber bundle due to the capillary phenomenon, and the physiological saline or the conductive gel can be permeated into the fiber bundle in a short time. Normally, saline solution evaporates more easily than conductive gel and is not suitable for long-term measurement, but it is relatively small because the area in contact with the outside is relatively reduced by using the wet member as a fiber bundle. Deterioration of measurement data is less likely to occur even during long-term measurement. Saline or conductive gel may contain a small amount of a substance such as alcohol or glycerin that changes the viscosity or polarity of the liquid. The fibers of the fiber bundle may be carbon or conductive fibers. By making the fiber itself conductive, stable measurement can be performed even if the amount of physiological saline or conductive gel permeating the wet member is reduced. In addition, measurement can be performed without using a conductive substance such as physiological saline or a conductive gel. The wet member made of a fiber bundle is disposable, and it is good for hygiene to replace it for each subject or every measurement day. The surface of the dry electrode can be cleaned with alcohol or the like, but if the mechanism for holding the physiological saline or the like is integrated with the wet electrode, it is difficult to clean the surface after use.

Further, as a third means, the fiber bundle is composed of fibers extending in the same direction, and the direction in which the brain activity measuring electrode is brought into contact with the scalp is a direction substantially along the fiber extending direction of the fiber bundle. I tried to be.
When the fiber bundle of the wet member is in this direction, the protruding portion is pierced along the fiber direction of the wet member, which makes it easy to attach, and the fiber directions are more aligned than in the state of a random fiber mass. The wet member is better because the expanded fiber bundle supports the protruding portion more strongly from the surroundings and makes it difficult to come off from the protruding portion. Further, by setting the fiber direction of the fiber bundle to be perpendicular to the electrode, a passage of the conductive substance is formed between the scalp and the electrode, which facilitates the passage of energization.
Further, as a fourth means, the wet electrode mounting portion has a protruding portion, the wet member is made of a conductive gel, and the wet member is pierced and held in the protruding portion. ..
As the "conductive gel", for example, a known conductive gel such as a conductive hydrogel or a polymer gel carrying ions can be used. The conductive gel may be preliminarily impregnated with water, physiological saline, or the like, or may be impregnated with water, physiological saline, or the like at the time of use. The mechanical strength of the conductive gel is generally not high, and it is difficult to hold it for a long time, but by piercing the protruding portion and holding it, the wet member can be easily attached and detached.
Further, as a fifth means, a stopper portion that bulges outward with respect to the outer periphery of the adjacent protrusion-shaped portion is provided at the tip of the protrusion-shaped portion.
As a result, the wet member composed of the fiber bundle is strongly held by the more protruding portion.
Further, as a sixth means, the protruding portion is configured to be shorter than the guide body.
As a result, when the wet member is attached and used, the tip of the wet member held by the protruding portion does not protrude excessively from the guide body, and when the electrode for measuring brain activity comes into contact with the scalp. First of all, the guide body becomes easier to touch the scalp. In addition, when the wet member is not attached (attached / detached), the guide body is longer than the protruding part, so that the guide body first comes into contact with the scalp when the electrode for measuring brain activity comes into contact with the scalp. It will touch the scalp. Such functions of the guide body and the protruding portion may be realized in a well-balanced manner, particularly when the protruding portion is configured to be 1 mm to 2 mm shorter than the guide body.

Further, as a seventh means, the guide body is configured to have the same length or a long length as the scalp ground contact portion.
When the guide body is around the ground contact portion of the scalp, that is, at a position away from the electrode center line, and when the guide body is the same length or long as the ground contact portion of the scalp, the tip of the guide body is from the electrode center line. Is located at a distance, and the tip of the guide body surely comes into contact with the scalp first, so that the electrode for measuring brain activity is in an oblique state and it is unlikely that the tip of a part of the scalp grounding part will be grounded. Become. In particular, when the guide body is made of a flexible material, if the guide body is longer than the scalp ground contact portion, the scalp ground contact portion is attached to the scalp when the brain activity measurement electrode is attached to the wearer. This is good because the guide body bends until it touches the ground, and after touching the ground, the guide body repels the scalp, which increases the cushioning property and reduces pain and oppressive feeling when worn. When the guide body is longer than the scalp grounding portion in this way, the guide body serves as a guide body by contacting the tip of one of the guide bodies first and serving as a fulcrum when it comes into contact with the scalp. This is good because it functions and functions as a cushion body after the scalp ground contact portion comes into contact with the scalp.
Here, the "length" of the guide body and the scalp grounding portion is the "length in the height direction" at the electrode center position, and the degree of contact between the electrodes when the brain activity measuring electrode is grounded facing the scalp. It is important because it is related to. For example, the guide protrusion 13 which is the guide body of the electrode 5 and the first protrusion 9 which is the ground contact portion of the scalp shown in FIG. 3A of the first embodiment are open to the outside, so that the guide body is closer to the guide body. Is longer, but the height at the center position (length in the height direction) is the same for the guide body and the scalp ground contact portion. Therefore, when the guide body and the scalp ground contact portion are in direct contact with the scalp, the guide body and the scalp ground contact portion are equally in contact with the scalp surface.
In addition, as an eighth means, a plurality of the guide bodies are arranged at positions that surround the scalp ground contact portion in a scattered manner.
By surrounding the scalp grounding portion with the guide bodies arranged in a scattered manner in this way, one of the guide bodies first touches the scalp regardless of the direction in which the electrodes are in contact with the scalp. This makes it easier to solve the problem of being grounded only by the tip of a part of the scalp grounding part.

Further, as a ninth means, the guide body is set so that the tip side is open to the outside.
By doing so, when the electrode is tilted and approaches the scalp, the guide body is likely to come into contact with the guide body first at an outer position away from the electrode center line, and a moment is generated to correct the tilt. At this time, it is better that the guide body is opened outward at a position as far as possible from the center of the main body of the electrode, for example, near the edge of the main body, because the moment becomes large. In addition, when the guide body is made of a flexible material, if the tip of the guide body is open outward, it works as a cushion body to relieve pain and oppressive feeling during and during electrode mounting. Good. In particular, when the electrode grounding portion is configured to be shorter than the guide body, the guide body has a higher function as a cushion body, which is preferable.
Further, as a tenth means, the guide body is made of a flexible material so that the tip side is warped and opened toward the outside.
"The tip side is warped and opened outward" means that the meridian direction is gently curved so as to be convex inward in a quadratic curve. By doing so, when one of the tips of the guide body touches the scalp and serves as a fulcrum, the guide body can be cushioned, and the guide body can be attached until it comes into contact with the scalp ground contact portion. The pain can be reduced. Further, it is preferable that the guide body becomes a cushion body after the scalp ground contact portion comes into contact with the scalp, that is, during the electrode mounting, and it is possible to make it difficult to feel pain and oppressive feeling during the electrode mounting.
Further, as an eleventh means, the plurality of scalp grounding portions are arranged so as to be rotationally symmetric with the center of the main body as the center of rotation.
As a result, no matter how the electrode is tilted in any direction, there is a guide body around it, so the problem that only the tip of a part of the scalp grounding part is grounded regardless of the direction is solved. It becomes easy to be done.

Further, as a twelfth means, the scalp grounding portion is made of a synthetic resin material having conductive performance.
By composing it from a synthetic resin material with conductive performance, the subject's head does not feel cold compared to a metal material, and a soft material (“flexible material”) can be used, making it easy for the subject to use. An electrode for measuring brain activity can be provided.
Here, the "synthetic resin material having conductive performance" includes both the case where the synthetic resin itself has conductive performance and the case where the non-conductive synthetic resin contains a conductive substance to have conductive performance. Including. When a non-conductive synthetic resin contains a conductive substance to have conductive performance, even if the non-conductive synthetic resin material contains a conductive substance, the non-conductive synthetic resin material becomes A substance containing a conductive substance may be coated. Further, when the synthetic resin material itself has conductivity, a substance containing a conductive substance may be coated. When the synthetic resin contains a conductive substance, it is preferable to contain a fine conductive substance group. Examples of the "conductive substance group" include gold, silver, platinum, copper, nickel, aluminum, carbon black, carbon nanotubes, carbon nanohorns, carbon nanobrushes, polythiophene-based, polyacetylene-based, polyaniline-based, polypyrrole-based, PEDOT /. PSS and the like. Here, "fine" is at least one of fibrous and powdery forms. It may contain a conductive substance in a form other than fibrous or powdery (for example, granular or thick fibrous).
If the entire electrode is made of such a material, sufficient conductivity can be obtained even if the synthetic resin material is used as a base, and a plastic material having good moldability and low cost can be used.
The "synthetic resin material" includes thermoplastic and thermocurable plastics, synthetic rubbers, and thermoplastic elastomers, for example, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, urethane-based thermoplastic elastomers, and vinyl chloride-based thermals. Plastic elastomers, polyamide-based thermoplastic elastomers, ester-based thermoplastic elastomers, polyethylene, polycarbonate, polyvinyl chloride, polypropylene, polystyrene, polylactic acid, nylon, polyacetal, modified polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, polymethylmethacrylate, polyamide , Polyurethane, Polygonate, Polyester, Elastomer, ABS Resin, AS Resin, Elastomer Resin, Urea Resin, Phenolic Resin, Melamine Resin, Styrene / butadiene Rubber, Isoprene Rubber, Silicone Resin (Silicone Rubber), Ethylene / Propylene Rubber, Butyl Rubber, Chloroprene Refers to rubber, elastomer nitrile / butadiene rubber, fluororubber, etc.
The "flexible material" is, for example, a material that is flexible and deforms when bent or pushed under external pressure, but returns to its original shape when the pressure is removed. Contains synthetic rubber, thermoplastic elastomers, or foamed plastics, such as styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, urethane-based thermoplastic elastomers, vinyl chloride-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, and ester-based thermoplastic elastomers. , Styrene / butadiene rubber, isoprene rubber, elastomer rubber, ethylene / propylene rubber, butyl rubber, chloroprene rubber, acrylonitrile / butadiene rubber, fluororubber, flexible polyurethane foam, polyethylene foam, polystyrene foam, polypropylene foam and the like are preferable. It is not only the scalp grounding portion that is composed of the "flexible material", but the entire electrode may be composed of the flexible material.

Further, as a thirteenth means, the scalp grounding portion and the wet electrode mounting portion are integrally molded as a synthetic resin molded product.
This is because if it can be integrally molded, it is advantageous in terms of cost and durability can be improved. Further, since the electrode for measuring brain activity is attached to the head of the subject, it is preferable to make the structure as simple as possible so that the weight of the electrode body can be reduced. It is better to integrally mold not only the scalp grounding portion and the wet electrode mounting portion but also the entire electrode for measuring brain activity. In particular, when the scalp grounding portion also serves as the wet electrode mounting portion, it is preferable that the scalp grounding portion is integrally molded with the same material.
Further, as a fourteenth means, the scalp ground contact portion and the guide body are made of different materials.
For example, the scalp grounding part is made of a conductive material and the guide body is made of a non-conductive material, or the guide body is made of a conductive material different from the scalp grounding part and an insulator is arranged between the main body and the electric signal is blocked. Can be done. Further, the scalp grounding portion may be made of a metal material, and the guide body may be made of a non-conductive synthetic resin material.

Further, as a fifteenth means, an electrode fixing portion was formed at an upper position of the scalp grounding portion.
The electrode fixing portion is a part for fixing the electrode for measuring brain activity. As a result, the electrodes for measuring brain activity can be fixed to a head-mounted base such as a head cap or a headset by using the electrode fixing portion. If such an electrode fixing portion is integrally molded together with the scalp grounding portion and the guide body, it is cost-effective. Further, since the electrode for measuring brain activity is attached to the head of the subject, it is preferable to make the structure as simple as possible so that the weight of the electrode body can be reduced.
Further, as a 16th means, the brain activity was recorded as an electroencephalogram.
As a seventeenth means, the brain activity was recorded as a magnetoencephalogram.
By using brain activity such as these, the time resolution is high, and it becomes possible to measure the brain activity in milliseconds. The quality of the measurement data of these brain activities is determined by the state of contact of the electrodes for measuring brain activity with the scalp. It is particularly preferable to be able to perform measurement by combining a dry method and a wet method depending on the condition and environment of the subject.

Further, as the eighteenth means, the electrodes for measuring brain activity according to any one of the means 1 to 17 are attached to the base for attaching the head to form the head attachment device.
A specific head-mounted device provided with the above-mentioned electrodes for measuring brain activity can hold the electrodes on the head, especially with a dry electrode that does not use paste or gel, so that the electrodes can be brought into contact with the scalp. It will be easy. Further, even when a wet member containing a physiological saline solution, a conductive aqueous solution, a conductive gel, or the like is attached to the wet electrode mounting portion and used, the electrode can be fixed. In particular, it may be attached via an electrode fixing portion. Here, the "head wearing device" is a head cap having a hole at the electrode position, a headset for mounting the electrode on the head, a head band, or the like. With such a "head wearing device", it is difficult to adjust the orientation of the electrodes when wearing the subject, and even if the orientation of the electrodes is not directly facing the scalp, it may not be noticed, but brain activity. By allowing the measurement electrodes to face each other independently, it takes time to adjust the orientation of each electrode when the head mounting device is attached, and it is confirmed that the orientation of each electrode is correctly in contact with each other. It is good because there is no need.
Further, as a 19th means, the electrode for measuring brain activity was fixed to an amplification device for amplifying a brain activity signal.
By immediately amplifying the electroencephalogram measured by this with an amplification device, the influence of radio waves and magnetic fields from the outside is reduced, so that it is possible to acquire a high-quality electroencephalogram with less external noise.
Further, as a twentieth means, the amplification device was fixed to the base side, and the brain activity measurement electrode was supported by the catch portion of the amplification device.
As a result, the amplification device can be attached in advance as a member on the base side, and the electrode for measuring brain activity can be attached to such an amplification device. Therefore, only the electrode for measuring brain activity can be attached to the base side independently. Improves sex.
Further, as a 21st means, the electrode for measuring brain activity is made detachable from the catch portion of the amplification device.
As a result, the work of fixing the electrodes for measuring brain activity to the base side can be easily performed.
Further, as a 22nd means, the base is sandwiched between the amplification device and the base holding portion for mounting the head formed on the upper part of the scalp grounding portion.
As a result, the electrodes for measuring brain activity are firmly fixed at a predetermined position with respect to the base. It is possible to measure the brain activity of a subject simply by wearing a head-mounted device provided with electrodes for measuring brain activity that are firmly fixed in this way.

Further, as the 23rd means, the brain activity measuring electrode of any of the 1st to 17th means is provided, and the brain activity is measured based on the brain activity signal obtained by the brain activity measuring electrode. did.
By doing so, it is possible to reduce the time and effort required to attach the electrodes to the subject, and it is possible to provide a brain activity measurement system in which the measurement preparation time is shortened. In addition, by using this brain activity measurement system, it becomes possible to reduce the burden on the subject at the time of wearing and obtain high-quality measurement data. This is because in the measurement of brain activity, if pain or discomfort occurs while wearing the electrodes for measuring brain activity, it will be a measurement of brain activity such as unintended pain or discomfort. This is because the feeling of wearing the electrodes for measuring brain activity is important for acquiring the desired brain activity.
Further, as the 24th means, a head-mounted device of any of the 18th to 22nd means is provided, and the brain activity is measured based on the brain activity signal obtained by the brain activity measuring electrode. ..
By doing so, it is possible to reduce the time and effort required to attach the head wearing device to the subject, and it is possible to provide a brain activity measurement system in which the measurement preparation time is shortened. In addition, by using this brain activity measurement system, it becomes possible to reduce the burden on the subject at the time of wearing and obtain high-quality measurement data. This is because in the measurement of brain activity, if pain, discomfort, etc. occur while wearing the head wearing device, the brain activity such as unintended pain, discomfort, etc. will be measured. By reducing the pain, discomfort, etc. caused by wearing the electrodes for measuring brain activity, it is possible to reduce the pain, discomfort, etc. when wearing the head wearing device.
The inventions of the first to twenty-fourth means described above can be arbitrarily combined. In particular, it is preferable to include the configuration of the first means and to include at least one configuration and combination of each invention of the second to twenty-fourth means. Any component of each invention of the first to twenty-fourth means may be extracted and combined with other components.

In the above invention, when the electrodes for measuring brain activity are used, the electrodes for measuring brain activity are not balanced in an oblique state regardless of the shape of the head of the subject, and the electrodes are likely to come into direct contact with the scalp. After contacting the scalp, the burden on the subject due to wearing the electrodes can be reduced. In addition, when it is difficult to obtain measured values of brain activity due to the subject's constitution, temperature, humidity, etc., the electrode configuration can be easily adjusted, and in any case, the subject can obtain appropriate measured values with less burden. Become.

The schematic explanatory view of the state which uses the brain activity measurement system in 1st Embodiment. The block diagram explaining the electrical structure of 1st Embodiment. (A) is a front view, (b) is a bottom view, (c) is a plan view, and (d) is a sectional view taken along the line AA of (b) of the electrodes used in the first embodiment. A partially broken front view of the guide member used in the first embodiment. In the first embodiment, (a) is a partially enlarged partial cross-sectional explanatory view of a state in which an electrode is attached to a cap body, and (b) is an explanatory view of a state in which the electrode of (a) is grounded to the scalp. The explanatory view of the state in which the electrode is tilted and the tip of the guide body is in contact with the scalp in the first embodiment. (A) of the electrode used in the second embodiment is an explanatory view explaining a state immediately before the fiber bundle is pierced into the second protrusion, and (b) is a cross section of the state where the fiber bundle is pierced into the second protrusion. Figure. The electrode (a) used in the third embodiment is a front view, (b) is a bottom view, and (c) is a sectional view taken along line BB of (b). (A) is a perspective view, (b) is a front view, and (c) is a bottom view of the electrodes used in the fourth embodiment. In the electrode manufacturing process of the fourth embodiment, (a) is a front view of the first molded product, and (b) is an explanatory view of a state in which the first molded product is set in a mold. (C) is a bottom view of a wet member that can be attached to the first molded product and used, and (d) is a cross-sectional view taken along the line BB of (c). (A) is a front view of the electrodes used in the other embodiments, and (b) is an explanatory view of a state in which the electrodes are attached to the main body of the head mounting device. FIG. 5 is a cross-sectional view illustrating a modified example of the first embodiment. Schematic explanatory view of the state using the brain activity measurement system of another embodiment. The electrodes used in the fifth embodiment, (a) is a front view, and (b) is an explanatory view of a state in which the electrode of (a) is grounded to the scalp. The electrodes used in the sixth embodiment, (a) is a front view, (b) is an explanatory view of a state where the electrode of (a) is grounded to the scalp, and (c) is a wet member (c). Explanatory drawing of the state where the electrode of a) is grounded to the scalp, (d) is the explanatory view of the state where the electrode of (a) which changed the wearing state of the wet member is grounded to the scalp, (e) Bottom view. In the conventional electrode, (a) is an explanatory diagram of a state in which the electrode is correctly grounded to the scalp, and (b) is an explanatory diagram of a state in which the electrode is tilted and grounded to the scalp and is obliquely balanced. Explanatory drawing of the head region explaining the region where the electrode is slanted and easily balanced when the electrode is grounded to the scalp.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.
(First Embodiment)
As shown in FIG. 1, the electroencephalogram measurement system as the brain activity measurement system of the first embodiment of the present invention includes a headset 1 as a head-mounted device and a differential amplifier 2 as a first amplification device. , Computer 3. The headset 1 is a device for acquiring brain waves composed of a hard frame attached to the head of the appearance of an elastic C-shaped hair band called "headband" in Japan. A plurality of electrodes 5 for measuring the brain potential (voltage) are fixed to the back surface of the headset 1. The measurer puts the headset 1 in a fixed position for measuring the brain potential (voltage) in which the electrodes 5 reflect the brain waves (in the present embodiment, the electrodes 5 are three, and the F3 in the frontal region of FIG. 15). , Fz, F4), and wear it on the subject's head. In FIG. 1, the differential amplifier 2 is connected to the headset 1 by wire, but the differential amplifier 2 is built in the headset 1, the differential amplifier 2 and the headset 1 are connected by wireless communication, and the like. Variations are free.

As shown in FIGS. 3 to 5, the electrode 5 of the first embodiment is configured by combining the electrode body 6 and the guide member 7 fitted to the electrode body 6. First, the electrode body 6 will be described. The electrode 5 of the first embodiment is an example in which the wet member is not attached to the protrusion 11 which is the wet electrode mounting portion, that is, the electrode 5 is used in a detached state.
The electrode body 6 is made of a soft conductive material as an integrally molded product. As the material, a material appropriately selected from flexible synthetic resins can be used. In the first embodiment, as an example, a synthetic resin material (for example, polycarbonate or polyurethane resin) which is not conductive by itself is used, and carbon fibers which are conductive fibers are mixed in a dispersed manner. In the first embodiment, as an example, 5% by weight of carbon fibers having a length of about 2.0 mm is added to the synthetic resin.
The electrode body 6 includes a mounting portion 6A and a grounding portion base 6B projecting around the mounting portion 6A in a flange shape. The attachment portion 6A is a columnar core having a circular surface, and a constriction portion 8 for attachment is formed near an intermediate position in the vertical direction. The ground contact portion base 6B has a disk-shaped outer shape, and a step portion 10 into which a guide member 7 as a guide body is fitted is formed on the peripheral edge. On the back surface of the ground contact portion base 6B, six first protrusions 9 having the same shape as the scalp ground contact portion are formed near the peripheral edge of the ground contact portion base 6B so as to be equidistant and equidistant from the center of the ground contact portion base 6B. There is. The first protrusion 9 is erected (actually, hangs down) along the mounting direction of the electrode body 6, that is, in a direction orthogonal to the back surface of the ground contact portion base 6B facing the assumed scalp. .. The first protrusion 9 is arranged rotationally symmetrically with the center of the ground contact portion base 6B as the center of rotation. The first protrusion 9 has a rod-shaped outer shape with a circular cross section, and the tip (lower end) is chamfered in a hemispherical shape. Four second protrusions 11 having the same shape as wet electrode mounting portions are formed in the inner region surrounded by the first protrusion 9 on the back surface of the ground contact portion base 6B. The second protrusion 11 which is the wet electrode mounting portion has a long truncated cone shape. The second protrusion 11 is arranged rotationally symmetrically with the center of the ground contact portion base 6B as the center of rotation.
In the first embodiment, the length (length (height) at the center position) of the first protrusion 9 is 10 mm, and the diameter is 2 mm. The length of the second protrusion 11 (length (height) at the center position) is set to 3 mm.

Next, the guide member 7 will be described.
The guide member 7 is made of a material that is relatively harder than the conductive electrode body 6, and is configured as an integrally molded product. As the material, a material appropriately selected from flexible synthetic resins and the like can be used. In the first embodiment, a non-conductive synthetic resin material (for example, polycarbonate or polyurethane) is used as an example.
As shown in FIG. 4, the guide member 7 includes a ring-shaped base plate 14 having a circular through hole 12 formed in the center. Guide protrusions 13 having the same shape as six guide bodies are formed around the base plate 14 at equal intervals. The guide protrusion 13 has a rod-shaped outer shape with a circular cross section, and the tip (lower end) is chamfered in a hemispherical shape. Unlike the first protrusion 9, each guide protrusion 13 is erected with its tip facing outward, that is, inclined so as to open outward. This angle is approximately 10 to 45 degrees with respect to the extending direction of the first protrusion 9. In the first embodiment, the length (length (height) at the center position) of the guide protrusion 13 is 10 mm, and the diameter is 2 mm.
As shown in FIG. 3D, the guide member 7 is fitted so as to be placed on the grounding portion base 6B from above the mounting portion 6A of the electrode body 6, and fixed with an adhesive. The base plate 14 of the guide member 7 is engaged with the stepped portion 10 of the ground contact portion base 6B. At this time, as shown in FIG. 3B, the guide protrusion 13 is adjusted so that the center in the width direction is arranged on the virtual line extending from the center of the ground contact portion base 6B to the center in the width direction of the first protrusion 9. To do. That is, the guide protrusion 13 is arranged at an outward position adjacent to the first protrusion 9. The tips of all the guide protrusions 13 and the tips of all the first protrusions 9 are coplanar. Even if an adhesive is not used, the electrode body 6 is provided with a groove into which the base plate 14 of the guide member 7 is fitted, and the base plate 14 can be fitted and held in the groove. it can.

In the electrode 5 configured in this way, as shown in FIG. 5A, the mounting portion 6 is forcibly inserted into the preamplifier 15 and fixed to the headset 1.
The preamplifier 15 as the second amplification device is made of a flexible material (for example, foamed polyurethane), and the electronic board 15a which is the main body of the amplification device is housed inside. The preamplifier 15 is fixed to a flexible mounting plate 16 on the back surface of the headset 1. A recess 17 as a catch portion having a shape corresponding to the mounting portion 6A of the electrode 5 is formed from the lower surface to the inside of the preamplifier 15. The electrode 5 is detachable from the preamplifier 15 by the mounting portion 6A. The inside of the electronic substrate 15a has a structure that makes electrical contact with the electrode body 6. The preamplifier 15 of each electrode 5 is connected to the differential amplifier 2 via the cable 18, and the differential amplifier 2 is connected to the computer 3 via the cable 19.
Next, the electrical configuration of the electroencephalogram measurement system used in the first embodiment will be described with reference to FIG.
Each of the electrodes 5 is connected to an interface 20 arranged in the differential amplifier 2 via a preamplifier 15 and a differential amplifier 2, and potential data (voltage data) is generated as brain waves acquired by the computer 3 via the interface 20. It is output.
The preamplifier 15 is attached to each electrode 5 and amplifies the acquired electroencephalogram voltage at that position. The differential amplifier 2 includes a differential amplifier circuit, calculates and amplifies the electroencephalogram voltage and potential difference obtained from a reference electrode (not shown). Further, the differential amplifier 2 has a function of reducing noise by a built-in filter circuit. The potential data amplified by the differential amplifier 2 is output to the computer 3 as detection target data via the cable 19.
The computer 3 is composed of a CPU (central processing unit) 21, a storage device 22, and peripheral devices thereof. The CPU 21 performs arithmetic processing based on a program stored in the storage device. The storage device 22 stores basic programs such as a program for controlling the operation of the CPU 21 and an OA processing program (for example, a Japanese input function, a printing function, etc.) that manages functions that can be applied in common to a plurality of programs. ing. Further, a program for capturing potential data, a program for calculating potential difference, a program for calculating reliability of measurement data, a program for analyzing and displaying potential data, and the like are stored. An input device 23 (mouse, keyboard, etc.) and a monitor 24 are connected to the CPU 21. Measurement results such as brain waves and differences obtained on the monitor 24 can be displayed.

The usage and operation of the headset 1 and the electrode 5 configured as described above will be described.
When the subject wears the headset 1 as shown in FIG. 1, the electrode 5 in the state of FIG. 5A fixed to the mounting plate 16 is pressed against the scalp. At this time, if the electrode 5 is not tilted, the tips of all the first protrusions 9 come into contact with the scalp as shown in FIG. 5 (b), and the pressing force of the headset 1 acts on the scalp, but the load is applied. Is dispersed so that the scalp does not hurt.
However, the frontal region has a large difference in the shape of the individual's head, and depending on the person, the angle at which the electrodes are grounded is not necessarily the ideal contact state as shown in FIG. 5 (b), for example, FIG. There is a possibility that the electrode 5 touches the scalp at such an angle. Since the shape of the human head varies greatly from person to person, there is a possibility that the tips of all the songs touch the scalp at all electrode positions at angles as shown in FIG. 6, but in the examination of the inventor, especially in FIG. Electrodes centered on the electrodes of the frontal, midline frontal, parietal, and midline parietal shown (F3, Fz, F4, P3 in FIG. 15). Pz, P4 and the electrodes around it) have a high possibility.
Here, FIG. 6 will be described with reference to the conventional example of FIG. 16 (b) as a comparison target.
As shown in FIG. 16B, in the conventional configuration without a member such as the guide protrusion 13 of the first embodiment, the protrusions which are the scalp grounding portions may be in contact with each other and may be balanced. .. That is, in FIG. 16B, the direction in which the load is applied is the direction of the head at the position where the protrusions abut, and the large load of the head mounting device (headset 1 in the embodiment) is concentrated on the head at one point. It will end up.

On the other hand, in FIG. 6, since the guide protrusion 13 is arranged closer to the outside of the ground contact portion base 6B and is formed so as to be inclined so that the lower end opens outward, the guide protrusion 13 is hit by an expected degree of inclination. The center of gravity of the load does not come near the contact position. Further, the guide protrusion 13 is outside the first protrusion 9 which is the ground contact portion of the scalp and is longer than the first protrusion 9.
That is, due to the presence of the guide protrusion 13, the center of gravity of the load is always arranged to be inside the guide protrusion 13, and when the electrode 5 is tilted, the guide protrusion 13 always touches the scalp first. It is configured in.
Therefore, when the electrode 5 approaches the scalp diagonally, the tip of the guide protrusion 13 first touches the scalp, and the electrode 5 faces the scalp and the back surface of the grounding portion base 6B around the grounding point as shown by the arrow in FIG. A moment will act in the direction. By this action, the posture of the tilted electrode 5 is corrected and the first protrusion 9 comes into contact with the scalp. Then, when the first protrusion 9 touches the scalp, electrical information can be acquired.
Theoretically, if the angle of the electrode 5 becomes extremely steep, the center of gravity of the load will come to the position of the guide protrusion 13, but that is because the electrode 5 is tilted by nearly 90 degrees. The headset 1 configuration of the first embodiment does not tilt so much. What is assumed here is the inclination of the electrode 5 based on the difference in the head shape of the subject and the like.

With the above configuration, the following effects are obtained in the first embodiment.
(1) When the wearer wears the headset 1, when the electrode 5 is tilted with respect to the scalp, the guide protrusion 13 first touches the scalp of the subject as the wearer approaches the scalp, and then the guide protrusion 13 touches the scalp of the subject. As a base point, the electrode 5 moves so that the angle is corrected by the moment. Therefore, even if there is a slight difference in the head shape of the subject and the electrode 5 is tilted and abutted against the scalp, the first protrusion 9 which is the scalp grounding portion can be reliably grounded, and the electrode 5 is placed on the scalp. It will be in direct contact with each other, which contributes to the acquisition of accurate electrical information.
(2) Since the first protrusion 9 is rotationally symmetric and the guide protrusion 13 is arranged on the outside of each of the first protrusions 9, the angle is corrected regardless of the direction in which the electrode 5 is tilted. Will be done.
(3) Since the tip side of the guide protrusion 13 is open outward, a narrow angle is formed between the scalp where the guide protrusion 13 touches the ground and the guide protrusion 13, so that a moment is likely to be generated.
(4) Since the tip side of the guide protrusion 13 is open outward, that is, the end side is closed inward, it is not necessary to widen the electrode holding portion of the headset 1, and the degree of freedom in designing the headset 1. Can be raised.

(Second Embodiment)
The second embodiment is a variation of the electrode 5 of the first embodiment. In the first embodiment, an example in which a wet member is not attached to the second protrusion 11 and used as a dry electrode is shown, but in the second embodiment, a dry type and a wet type with a wet member attached are shown. The electrode 5 having both of them will be described. The detailed description of the configuration common to the first embodiment will be omitted, and the points different from the electrode 5 of the first embodiment will be mainly described. In the drawings, the members common to the electrode 5 of the first embodiment are given common numbers, and detailed description thereof will be omitted.
As shown in FIGS. 7A and 7B, a fiber bundle 31 which is a wet member is attached to the second protrusion 11 of the electrode 5 of the second embodiment. The fiber bundle 31 is an aggregate of cylindrical fibers, and the tip is chamfered. The fiber bundle 31 has a diameter of φ10 mm and a length of 8 mm. The fiber bundle 31 is a bundle of nylon fibers.

When attaching the fiber bundle 31 to the electrode 5 arranged on the headset 1, the person who operates the fiber bundle 31 first soaks the fiber bundle 31 in a physiological saline solution to hold the physiological saline solution inside the fiber bundle 31. Alternatively, the conductive gel is hung on the fiber bundle 31 and held. A fiber bundle 31 holding a conductive substance such as physiological saline or a conductive gel is arranged at a position facing the region surrounded by the first protrusion 9 on the back surface of the ground contact portion base 6B of the electrode 5, and the fiber bundle 31 is placed on the electrode. It is pushed into the area inside the first protrusion 9 of 5. At that time, the fiber bundle 31 is pushed in so that the extending direction of the fiber is the longitudinal direction of the first protrusion 9 and the second protrusion 11, that is, the direction in which the electrode 5 is in contact with the scalp.
When the fiber bundle 31 is pushed in, the periphery of the fiber bundle 31 comes into light contact with the first protrusion 9. The second protrusion 11 pierces the fiber bundle 31 from the tip side thereof and is buried in the fiber bundle 31. At this time, since the second protrusion 11 is pierced in a direction substantially along the extending direction of the fiber of the fiber bundle 31, the second protrusion 11 is easily pierced, and once stabbed, it is removed by the second protrusion 11. Since the force held by the returning repulsive force of the fibers pushed toward the side acts, the fiber bundle 31 is difficult to come off from the second protrusion 11. Further, in the second embodiment, since the fiber bundle 31 is also in contact with the surrounding first protrusion 9, it becomes more difficult to come off.
With this configuration, in the second embodiment, in addition to the effects of (1) to (4) of the first embodiment, in addition to the effects of the first embodiment.
(5) Since the electrode 5 having both the dry type and the wet type can be used for the headset 1, electrical information can be acquired reliably and accurately.
(6) When it is difficult to acquire brain waves with a dry electrode due to the constitution of the subject, temperature, humidity, etc., a wet member can be attached as necessary to measure as a wet electrode. Further, when the measurement can be performed without the wet member, the subject's brain wave can be measured as a dry electrode.

(Third Embodiment)
The third embodiment is a variation of the electrode 5 of the first embodiment. Therefore, detailed description of the configuration common to the first and second embodiments will be omitted, and the points different from the electrode 5 of the first embodiment will be mainly described. In the drawings, the members common to the electrode 5 of the first embodiment are given common numbers, and detailed description thereof will be omitted.
As shown in FIGS. 8A to 8C, the electrode 25 of the third embodiment is configured by combining the electrode body 26 and the guide member 27 in the same manner as the electrode 5 of the first embodiment. ing. The guide member 27 has exactly the same configuration as the guide member 7 of the electrode 5 of the first embodiment. The electrode body 26 differs from the electrode body 6 of the electrode 5 of the first embodiment only in the configuration of the first protrusion 29 which is the scalp grounding portion and the second protrusion 30. Therefore, the configuration of the first protrusion 29 and the second protrusion 30 will be described in detail.
On the back surface of the ground contact portion base 6B, six first protrusions 29 having the same shape as the scalp ground contact portion are formed so as to be equidistant and equidistant from the center of the ground contact portion base 6B. The first protrusion 29 has a rod-shaped outer shape with a circular cross section, and the tip (lower end) is chamfered in a hemispherical shape. While the first protrusion 9 of the first embodiment extends in a direction orthogonal to the surface direction of the back surface of the ground contact portion base 6B, each first protrusion of the third embodiment 29 is given an inclination at the same angle and in the same direction as each guide protrusion 13 of the adjacent guide member 27. That is, the first protrusion 29 is formed so as to be inclined with respect to the ground contact portion base 6B. Since the base side of the first protrusion 29 moves toward the center of the back surface of the ground contact portion base 6B and the area of the region near the center of the back surface of the ground contact portion base 6B becomes narrower, the second protrusion 11 of the first embodiment In contrast to the four provided, in the third embodiment, only one corresponding second protrusion 30 is formed in the center of the ground contact portion base 6B. Also in the third embodiment, the tips of all the guide protrusions 13 and the tips of all the first protrusions 29 are coplanar.
With such a configuration, in the third embodiment, in addition to the effects of (1) to (6) of the first embodiment, in addition to the effects of the first embodiment.
(7) Since the formation position of the first protrusion 29 can be moved toward the center of the ground contact portion base 6B, the ground contact portion base 6B can be made smaller. As a result, the electrode 25 can be miniaturized, and the degree of freedom in design when attaching a head-mounted device such as the headset 1 is increased.
(8) When the fiber bundle 31 is used for the electrode 25 as the electrode 25 having both the dry type and the wet type as in the second embodiment, the fiber bundle 31 is pushed in the grounding portion base 6B direction. The action when the second protrusion 30 pierces the fiber bundle 31 is the same as that of the second embodiment, but since the base side of the first protrusion 29 is narrow, the fiber bundle 31 is the first. It will be strongly held near the base of the protrusion 29.

(Fourth Embodiment)
The first to third embodiments show the embodiment as an example of the electrode 5 (25) formed by combining the separate electrode body 6 (26) and the guide member 7 (27). In the fourth embodiment, the case where these are integrated will be described. The electrode 35 of the fourth embodiment is also used by being mounted on the headset 1 shown in FIG. 1, but the electrical configuration of the headset 1 and its peripheral devices, the mounting structure on the head mounting device side, etc. As shown in FIGS. 9A to 9C, which will be described specifically for the electrode 35, the electrode 35 of the fourth embodiment includes a truncated cone-shaped electrode body 36. The electrode body 36 has an outer circumference that gently bulges so that the meridian direction is convex outward in a quadratic curve, and the upper surface 36a and the bottom surface 36b of the electrode body 36 are configured to be parallel to each other in a plane. An electrode fixing portion 37 is formed on the upper surface 36a of the electrode body 36. The electrode fixing portion 37 is composed of a pillar portion 37a having a circular cross section and a spherical connecting portion 7b formed on the upper portion of the pillar portion 37a. The electrode fixing portion 37 serves as an energizing portion for the preamplifier 15. Four protrusions 38 are formed on the bottom surface 36b of the electrode body 36 as a first scalp grounding portion. The protrusion 38, which serves as both the wet electrode mounting portion and the scalp grounding portion, has a cylindrical shape with a circular cross section and protrudes downward. The protrusions 38 are arranged so as to be point-symmetrical or mirror-imaged in all directions equidistant from the center position of the bottom surface 36b. The lower end corner of the protrusion 38 is smoothly chamfered.

The first leg 39 and the second leg 40 as the second scalp grounding portion are radially arranged and formed at the lower position of the outer circumference of the electrode body 36 (the center is also lower in the vertical direction). .. The first leg 39 and the second leg 40 are arranged so that four legs of the first leg 39 and the second leg 40 extend alternately and at equal intervals from the same height position on the outer circumference of the electrode body 36. The first leg portion 39 and the second leg portion 40 are provided with a long first curved portion 39a and a second curved portion 40a having a circular cross section extending outward with the outer periphery of the electrode body 36 as a base, respectively. ing. The first curved portion 39a is configured to have the same thickness as the second curved portion 40a, but the first curved portion 39a is relatively longer than the second curved portion 40a. That is, the configuration is such that the second scalp grounding portions having different lengths are mixed. The first curved portion 39a and the second curved portion 40a are curved so as to be convex outward, extend outward, and gently hang downward. A contact portion 41 is formed at the tips of the first curved portion 39a and the second curved portion 40a. The contact portion 41 has a spherical shape in which the tips of the first curved portion 39a and the second curved portion 40a are inflated. As shown in FIG. 9C, the spherical apex position of the contact portion 41 points in the downward direction. As shown in FIG. 9B, the contact portion 41 of the first leg portion 39 is arranged below the contact portion 41 of the second leg portion 40, and as shown in FIG. 9C, In bottom view, the contact portion 41 of the first leg portion 39 and the contact portion 41 of the second leg portion 40 are arranged so as to be equidistant from the center of the electrode body 36.
As an example of the dimensions, the electrode 35 of the fourth embodiment has an outer diameter of 14 mm, a height of 12 mm, a circular diameter of the first and second curved portions 39a and 40a having a circular cross section of 1.2 mm, and a contact portion 41. The diameter of the protrusion 38 is 2.4 mm, the height of the protrusion 38 is 1.5 mm, and the diameter of the circular cross section is 1.2 mm.

The electrode 35 having such an appearance configuration is composed of two types of synthetic resins by two-color molding. The electrode 36 is formed by the following procedure.
First, as shown in FIG. 10A, the first molded product 43 is molded. The first molded product 43 is molded with a mold (not shown). The first molded product 43 has a portion that will become a part of the electrode body 36, an electrode fixing portion 37, a protrusion 38, and a second leg portion 40 in the future.
As shown in FIG. 10B, the first molded product 43 is arranged in the mold 44. A cavity 45 having a shape as shown by a broken line is formed around the first molded product 43 of the mold 44. The cavity 45 is filled with the molten resin, and after solidification, the mold is released from the mold 44 to form the second molded product, that is, the electrode 36 so as to surround the first molded product 43 (FIG. 9 (FIG. 9). a) to (c) states).
In the electrode 36, the first molded product 43 is made of a conductive soft material (flexible material) as an integrally molded product. As the material, a material appropriately selected from flexible synthetic resins can be used. As an example, a synthetic resin material (for example, polycarbonate, polyurethane resin, silicone) which is not conductive by itself is used, and carbon fibers which are conductive fibers are mixed in a dispersed manner. In the fourth embodiment, as an example, carbon fibers having a length of about 2.0 mm are added to the synthetic resin by a weight ratio of 15%, and the synthetic resin has conductivity.
On the other hand, a part of the electrode body 36 formed in the cavity 45 which is the outer skin of the electrode 36 and a part which becomes the first leg 39 are non-conductive. As an example, it is composed of a non-conductive thermosetting synthetic resin (for example, a silicone resin). The legs 39 are made of a flexible material.
A wet member 60 having a recess 61 having the same shape as the protrusion 38 shown in FIGS. 10 (c) and 10 (d) can be attached to or detached from the four protrusions 38 of the electrode 35. The wet member 60 is formed of a gel carrying ions (conductive gel) and contains water.

When the electrode 35 having such a configuration is used without attaching the wet member 60 to the protrusion 38, the electrode 35 is fixed to the back surface of the headset 1 in the same manner as in the first embodiment, and the subject attaches the headset 1. If the electrode 35 is tilted and touches the scalp at that time, the contact portion 41 of the long-legged first leg 39 first touches the ground, and the electrode 35 is the electrode body 36 based on this grounding point. A moment acts in the direction facing the bottom surface 36b of the above, and the posture is corrected. At the same time, the leg 39 bends outward so that the electrode 35 faces the scalp, and the contact portion 41 at the tip of the leg 40, which is the scalp contact portion, becomes the scalp. Will come into contact with. Since the legs 39 and the legs 40 are made of flexible materials, the electrodes 35 have the legs 40 and the legs 39 further expanded after the abutting portion 41 abuts on the scalp, and the protrusions 38 hit the scalp. The contact stabilizes the posture of the electrodes. At this time, the protrusion 38 functions as a scalp contact portion. On the other hand, when the wet member 60 is attached to the protrusion 38 of the electrode 35 and used, after the contact portion 41 at the tip of the leg portion 40, which is the scalp contact portion, comes into contact with the scalp, the leg portion 40 is further attached. The legs 39 expand, and the tip of the wet member 60 comes into contact with the scalp to stabilize the posture of the electrodes. At this time, the protrusion 38 functions as a wet electrode mounting portion.
With such a configuration, in the fourth embodiment, in addition to the effects of (1) to (4) of the first embodiment and (5) to (6) of the second embodiment. When the first and second legs 39 and 40 come into contact with the scalp, the first curved portion 39a and the second curved portion 40a bend, so that the load is not applied at once and cushioning property is obtained and the scalp becomes painful. Hateful. Further, by giving the protrusion 38 two roles of a scalp grounding portion and a wet electrode mounting portion, it is possible to provide an electrode having a simple electrode configuration, a good wearing feeling, and capable of recording brain activity with high accuracy.

(Fifth Embodiment)
The fifth embodiment is a variation of the electrode 5 of the first embodiment. Therefore, detailed description of the configuration common to the first embodiment will be omitted, and the points different from the electrode 5 of the first embodiment will be mainly described. In the drawings, the members common to the electrode 5 of the first embodiment are given common numbers, and detailed description thereof will be omitted. The fifth embodiment is an example in which the guide body is made of a flexible material and the scalp mounting portion is shorter than the guide body.
As shown in FIG. 14A, the first protrusion 71, which is the scalp mounting portion of the electrode 70, is shorter than the guide protrusion 72, which is the guide body. For example, in the fifth embodiment, the length of the first protrusion 71 (the length (height) at the center position) is 8.5 mm, and the length of the guide protrusion is 10 mm. At the time of use, in the electrode 70, one of the guide protrusions 72 first abuts on the scalp to serve as a fulcrum, and then the electrode abuts directly on the scalp surface as shown in FIG. 14 (b). At that time, the guide protrusion 72 bends and spreads outward. In the process of expanding the guide protrusion 72, since the guide protrusion 72 has flexibility, it acts as a cushion, weakens the pressure on the scalp during wearing, and improves the wearing feeling. Further, as shown in FIG. 14B, even when the electrode is in contact with the scalp, the guide protrusion 72 is flexible, so if the electrode is pressed too much against the scalp, it repels appropriately and is excessively repelled against the scalp. Prevent pressure. The flexible guide protrusion 72 thus has a role as a cushion body.

(Sixth Embodiment)
The sixth embodiment is a variation of the electrode 5 of the first embodiment. Therefore, detailed description of the configuration common to the first embodiment will be omitted, and the points different from the electrode 5 of the first embodiment will be mainly described. In the drawings, the members common to the electrode 5 of the first embodiment are given common numbers, and detailed description thereof will be omitted. As shown in FIG. 15A, the sixth embodiment is an example of an electrode in which the electrode 80 is integrally molded with a flexible and conductive material, and the guide body, the scalp grounding portion, and the scalp grounding portion. It can also serve as a part and a wet electrode mounting part.
The electrodes 80 are a plurality of first legs 81 as guide bodies (six at equal intervals in this embodiment) and a plurality of first legs 81 as scalp grounding portions (six at equal intervals in this embodiment). It has two legs 82. The first leg 81 surrounds the second leg 82. The first leg 81 is a rod-shaped member having a circular cross section, and its tip is chamfered in a hemispherical shape. The first leg 81 is configured to extend obliquely outward when viewed from the center of the electrode and to be concave outward when viewed from the center of the electrode. The second leg 82 is formed in a long truncated cone shape that tapers toward the tip. The second leg 82 is configured to be slightly shorter than the first leg 81 in a straight line distance from the back surface of the ground contact portion base 6B.
When the electrode 80 having such a configuration is used, when the electrode abuts on the scalp, one of the outermost circumferences of the first leg 81 first abuts on the scalp and serves as a fulcrum to serve as a guide body. When used without a wet member as in 15 (b), after facing the scalp, the first leg 81 expands until the second leg 82 abuts on the scalp. At this time, the legs 81 and 82 function as scalp grounding portions. The wet member 83 of FIG. 15C is a conductive gel and is molded into a shape that can be attached to the legs 82. When the wet member 83 is attached to the second leg 82 and used as shown in FIG. 15C, the first leg 81 functions as a guide body and then spreads until the wet member 83 comes into contact with the scalp. become. At this time, the second leg 82 is a wet electrode mounting portion, and the leg 81 is a scalp grounding portion that also serves as a guide portion. In this way, the electrode 80 can be used as a dry electrode as shown in FIG. 15 (b) or as a wet electrode as shown in FIG. 15 (c) depending on whether or not a wet member is combined, and the constitution and environment (air temperature / room temperature) of the subject can be used. ) Etc., the electrode characteristics can be changed by a simple procedure. A small notch (not shown) is formed in the wet member 83 corresponding to the position of the tip of the second leg 82, and the second leg 82 is pierced and fixed in the notch. For example, if the material of the wet member 83 is a fiber bundle, no cut is required.

If at least one of the guide body and the scalp grounding portion and the scalp grounding portion and the wet electrode mounting portion can be shared as in this example, the electrodes can be made compact and simple. On the other hand, when the guide body and the scalp grounding part and the scalp grounding part and the wet electrode mounting part are not shared, it is easy to design each as a separate function, and it is possible to select the material hardness and conductivity suitable for each. Good because you can. The shape and material of the wet member and the conductive substance contained in the wet member shall be determined by assuming the scalp grounding state when the wet member is attached, together with the shape and material hardness of the guide body and the scalp grounding part. Is good.
When the guide body is made of a flexible material, the cross section of the guide body in the ruled line direction as in the first leg 81 of FIG. 15A is concave (inward) toward the outside when viewed from the center of the electrode. It is especially good that it is convex. By making it concave toward the outside in this way, when the guide body comes into contact with the scalp, the first leg 81 as the guide body bends in the direction in which it is already bent. It becomes easier to reduce the pressure properly. Further, even if the electrodes are pressed toward the scalp at the time of contact, they will repel appropriately.

Next, a case where the wet member 84 of FIG. 15 (e) is used as a variation of the wet member 83 will be described. The wet member 84 is composed of a fiber bundle impregnated with a physiological saline solution, and has a through hole 85 having a diameter corresponding to the distance between the second legs 82 and the mounting height when the wet member 84 is mounted on the second leg 82. It is formed. The wet member 84 is used to be arranged in the middle of the wet electrode mounting portion instead of the tip of the wet electrode mounting portion (second leg 82). As shown in FIG. 15D, the electrode 80 is brought into contact with the scalp in a state where the second leg 82 is fitted into the through hole 85 of the wet member 84. At this time, although the wet member 84 is not in contact with the scalp, the second leg 82 to which the wet member 90 is attached serves as the scalp grounding portion, and the physiological saline contained in the wet member 84 is transmitted through the wet electrode mounting portion. It will reach the surface of the scalp. As a result, even when the scalp surface is easily dried and the contact resistance is difficult to decrease, the brain activity can be measured with sufficient accuracy.

The above-described embodiment is merely described as a specific embodiment for exemplifying the principle of the present invention and the concept thereof. That is, the present invention is not limited to the above-described embodiment. The present invention can also be embodied in a modified manner as follows, for example.
The form and size of the electrodes 5, 25, 35, 70, and 80 of the first to sixth embodiments are examples, and other electrodes can be freely used.
The electrodes 5, 25, 35, 70, and 80 of the first to sixth embodiments are forcibly fitted and attached to the catch portion (recessed portion 17) formed in the preamplifier 15. For example. , It may be configured as shown in FIGS. 11A and 11B.
As shown in FIG. 11A, the electrode 45 has a configuration in which the electrode fixing portion 37 of the electrode 35 of the fourth embodiment is formed into a columnar electrode fixing portion 42, and a male screw portion 42a is formed on the outer periphery. A flange portion 43 is integrally formed at the lower position of the male screw portion 42a. The electrode 45 is integrally molded with a conductive material.
Such an electrode 45 is fixed to the headset 1 by a preamplifier 49 and a flange portion 43. The preamplifier 49 has a disk-shaped thin plate-like appearance, and a female screw portion 49a as a catch portion that can be screwed with the screw of the male screw portion 42a of the electrode fixing portion 42 is formed in the central through hole. The preamplifier 49 is arranged on the mounting hole 51 of the mounting plate 50 inside the headset 1, the male screw portion 42a is inserted from the inside of the mounting plate 50 to the outside, and the male screw portion 42a is inserted on the upper side (inside) of the cap body 53. Screw and fasten with the female screw portion 49a of the preamplifier 49. As shown in FIG. 9B, the mounting plate 50 is sandwiched between the preamplifier 49 and the flange portion 43 in a firmly fastened state, and the electrode 45 is fixed to the mounting plate 50. From such a fastened state, the male screw portion 42a can be removed from the mounting plate 50 of the electrode 45 by rotating the male screw portion 42a in the opposite direction to the female screw portion 49a.
Although the shape of the electrode 35 of the fourth embodiment is taken as an example in FIGS. 11A and 11B, it may be applied to other embodiments as well.

In the electrodes 5 and 25 of the first to third embodiments, the second protrusion 11 (30) has a long truncated cone shape that tapers toward the tip, but as shown in FIG. 12, for example, For example, a spherical stopper 47 having a bulging shape may be provided at the tip. This makes it more difficult for the fiber bundle 31 to come off from the second protrusion 11 (30).
In the first to fourth embodiments, the electrodes 5, 25, and 35 are attached to the headset 1, but the headset 1 is an example of a head-mounted device and is attached to another head. It may be attached to the device. For example, as shown in FIG. 13, it may be applied to a head cap 53 made of a flexible cloth or the like.
-In the first to third embodiments, the guide body 13 is made of a non-conductor. However, for example, an insulator layer is arranged on the boundary surface between the electrode body 6 and the guide member 7, and the guide member 7 may be made of a conductive material.
-In the above embodiment, for example, in order to make the electrode body 6 conductive, carbon fibers are mixed with the synthetic resin material as conductive fine particles. However, the present invention can be realized by another method such as coating the electrode surface with a conductive substance or constructing the electrode with the conductive substance itself without mixing such conductive fine particles with the material itself. , Included in the present invention.
-It is not always necessary to use a preamplifier when fixing the electrodes 5, 25 and 35. The electrodes 5, 25, and 35 may be fixed by means other than the preamplifier.
-In the above embodiment, an example of an electrode using a synthetic resin material is shown, but the electrode may be a metal. In the case of metal, for example, in FIG. 8, the tip of the first protrusion 29 and the tip of the second protrusion 30 in contact with the scalp should be plated with gold, silver / silver chloride or the like. Further, the guide protrusion 13 which is a guide body is preferably formed of a resin material which does not have conductivity. When the guide protrusion 13 is made of metal, it is preferable to insulate between the electrode 6 and the guide protrusion 13.
-Although the example in which the interface 20 connecting the differential amplifier 2 and the computer 3 is connected by wire has been described in the above embodiment, wireless communication or the like may be used. Further, the information transmission between the preamplifier and the differential amplifier is not limited to wired communication, and the use of wireless communication or the like is also included in the variation of the present invention.
The invention of the present application is not limited to the configuration described in the above-described embodiment. The components of each of the above-described embodiments and modifications may be arbitrarily selected and combined. Further, any component of each embodiment or modification, and any component described in the means for solving the invention or any component described in the means for solving the invention are embodied. And may be configured in any combination. We also intend to acquire the rights to these in the amendment or divisional application of the present application.
In addition, he / she intends to acquire the right to the whole design or the partial design by filing a change application to a design application. Although the entire drawing of the device is drawn with solid lines, it is a drawing that includes not only the whole design but also the partial design requested for a part of the device. For example, it is a drawing which includes a part of the device as a partial design regardless of the member as well as a part of the member of the device as a partial design. The part of the device may be a part of the device or a part of the member.

5, 25, 35, 45, 70, 80 ... Electrodes, 9, 29, 71 ... Protrusions as a scalp ground contact part, 13, 72 ... Guide protrusions as a guide body, 81 ... First leg as a guide body, 82 … The second leg as the scalp grounding part.

Claims (24)

One or more scalp grounding parts having a function of contacting the scalp to acquire electrical information,
With one or more guide bodies arranged around the scalp ground contact portion,
A wet electrode mounting portion formed in a plurality of inner regions of the scalp ground contact portion or shared with at least one of the scalp ground contact portions.
A wet member that can be attached to and detached from the wet electrode mounting portion,
With
Brain activity measurement characterized in that it is used as a wet electrode when the wet member is mounted on the wet electrode mounting portion, and is used as a dry electrode when the wet member is removed from the wet electrode mounting portion. Electrode for. The first aspect of the present invention is characterized in that the wet electrode mounting portion has a protruding portion, the wet member is composed of a fiber bundle, and the wet member is pierced and held in the protruding portion. The electrode for measuring brain activity described. The fiber bundle is composed of fibers extending in the same direction, and the direction in which the brain activity measuring electrode is brought into contact with the scalp is set to be substantially along the fiber extending direction of the fiber bundle. The electrode for measuring brain activity according to claim 2. The wet electrode mounting portion has a protruding portion, and the wet member is made of a conductive gel, and the wet member is pierced and held in the protruding portion. Electrode for measuring brain activity described in. The brain activity measurement according to any one of claims 2 to 4, wherein the tip of the protruding portion has a stopper portion that bulges outward with respect to the outer periphery of the adjacent protruding portion. Electrode for. The electrode for measuring brain activity according to any one of claims 2 to 5, wherein the protruding portion is formed to be shorter than the guide body. The electrode for measuring brain activity according to any one of claims 1 to 6, wherein the guide body is configured to have the same length or a long length as the scalp ground contact portion. The electrode for measuring brain activity according to any one of claims 1 to 7, wherein a plurality of the guide bodies are randomly arranged at positions surrounding the scalp ground contact portion. The electrode for measuring brain activity according to any one of claims 1 to 8, wherein the guide body has the tip side open outward. The electrode for measuring brain activity according to any one of claims 1 to 9, wherein the guide body is made of a flexible material and the tip end side is warped and opened outward. The electrode for measuring brain activity according to any one of claims 1 to 10, wherein the plurality of scalp grounding portions are arranged so as to be rotationally symmetric with the center of the main body as the center of rotation. The electrode for measuring brain activity according to any one of claims 1 to 11, wherein the scalp grounding portion is made of a synthetic resin material having conductive performance. The electrode for measuring brain activity according to claim 12, wherein the scalp grounding portion and the wet electrode mounting portion are integrally molded as a synthetic resin molded product. The electrode for measuring brain activity according to any one of claims 1 to 13, wherein the scalp grounding portion and the guide body are made of different materials. The electrode for measuring brain activity according to any one of claims 1 to 14, wherein an electrode fixing portion is formed at an upper position of the scalp grounding portion. The electrode for measuring brain activity according to any one of claims 1 to 15, wherein the brain activity is recorded as an electroencephalogram. The electrode for measuring brain activity according to any one of claims 1 to 16, wherein the brain activity is recorded as a brain magnetic field. A head-mounted device in which the brain activity measuring electrode according to any one of claims 1 to 17 is attached to a head-mounted base. The head-mounted device according to claim 18, wherein the brain activity measurement electrode is fixed to an amplification device that amplifies a brain activity signal. The head-mounted device according to claim 19, wherein the amplification device is fixed to the base side, and the brain activity measurement electrode is supported by a catch portion of the amplification device. The head-mounted device according to claim 20, wherein the brain activity measuring electrode is removable from the catch portion of the amplification device. The head according to any one of claims 18 to 21, wherein the base is sandwiched between the amplification device and a base holding portion for mounting the head formed on the upper part of the scalp grounding portion. Mounting device. A brain activity measurement system comprising the electrode for measuring brain activity according to any one of claims 1 to 17, and measuring brain activity based on a brain activity signal obtained by the electrode for measuring brain activity. A brain activity measurement system comprising the head-mounted device according to any one of claims 18 to 22, measuring brain activity based on a brain activity signal obtained by the brain activity measurement electrode.