JPWO2019078326A1 - Evaluation system, evaluation method, program, and non-temporary recording medium for brain activity measuring device - Google Patents

Abstract

An object of the present disclosure is to easily and appropriately evaluate the load applied to the head of the subject from the brain activity measuring device. The evaluation system (105) includes a head model (6) to which the headset (1) can be worn, and a converter (7) provided on the head model (6) to convert a load into an electric signal. The transducer (7) is arranged in the head model (6) at a site where the headset (1) receives a load from an electrode portion (11) that comes into contact with the scalp to measure brain activity.

Description

The present disclosure relates to an evaluation system, an evaluation method, a program, and a non-temporary recording medium of a brain activity measuring device. More specifically, the present disclosure describes an evaluation system, evaluation method, and program of a brain activity measuring device for evaluating the accuracy and safety of a brain activity measuring device for measuring the blood flow state of the brain surface of the cerebral cortex or the brain wave. , And non-temporary recording media.

As an example of the conventional brain activity measuring device, the electroencephalograph described in Patent Document 1 will be illustrated. The electroencephalograph described in Patent Document 1 includes a band-shaped body frame that extends from the parietal side toward the left and right tragus when worn on the head, and an electroencephalogram electrode that can move in the longitudinal direction of the body frame. It has. The electroencephalogram electrode is pressed against the head mainly by the spring force of the coil spring. However, if the force that presses the EEG electrode against the head is too strong, redness (red spots) is likely to occur where the EEG electrode is pressed, so press the EEG electrode against the scalp with an appropriate pressing force. It is desirable to hit.

By the way, various types of brain activity measuring devices other than the electroencephalograph described in Patent Document 1 are provided, and a member (electroencephalogram) that contacts a wide variety of brain activity measuring devices with the head in order to measure the brain activity. It is required to easily and appropriately evaluate the load applied to the head (electrodes, etc.).

JP-A-2016-220770

An object of the present disclosure is to provide an evaluation system, evaluation method, program, and non-temporary recording medium of a brain activity measuring device capable of easily and appropriately evaluating a load applied to a subject's head from a brain activity measuring device. It is to be.

In the evaluation system of the brain activity measuring device according to one aspect of the present disclosure, the brain activity measuring device having a contact portion that contacts the head of the subject in order to measure the brain activity of the subject contacts the contact portion. Equipped with a main body that can be installed in a state of being. The evaluation system includes a converter provided in the main body to convert a load into an electric signal. The converter is arranged in a portion of the main body that receives a load from the contact portion with the brain activity measuring device attached to the main body.

In the evaluation method of the brain activity measuring device according to one aspect of the present disclosure, the converter provided in the main body to which the brain activity measuring device can be attached is brought into contact with the head in order for the brain activity measuring device to measure the brain activity. Place it in the part that receives the load from the contact part. In the evaluation method, the load received by the portion from the contact portion is converted into an electric signal by the converter.

The program according to one aspect of the present disclosure causes a computer system to execute an evaluation method of a brain activity measuring device.

The non-temporary recording medium according to one aspect of the present disclosure is a non-temporary recording medium readable by a computer system in which a program for causing a computer system to execute an evaluation method of a brain activity measuring device is recorded.

FIG. 1 is a schematic view showing a usage state of an electroencephalogram measurement system including a headset, which is an evaluation target of the evaluation system according to the embodiment of the present disclosure, and a rehabilitation support system including the headset. FIG. 2 is a block diagram showing the configurations of the above-mentioned electroencephalogram measurement system and rehabilitation support system. FIG. 3A is a schematic top view showing a usage state of the headset as described above. FIG. 3B is a schematic front view showing a usage state of the headset as described above. FIG. 4 is a block diagram showing the configuration of the evaluation system as described above. FIG. 5 is an equivalent circuit of the converter in the evaluation system of the same. FIG. 6 is a perspective view of the head model in the same evaluation system. FIG. 7 is an exploded perspective view of the same head model. FIG. 8A is a front view of the same head model. FIG. 8B is a plan view of the same head model. FIG. 8C is a left side view of the same head model. FIG. 9A is a front view showing the first curve clearly on the same head model. FIG. 9B is a left side view in which the first curve and the second curve are clearly shown on the same head model. FIG. 10A is a front view of the load receiving seat in the same as above. FIG. 10B is a left side view of the load receiving seat of the same. FIG. 10C is a rear view of the load receiving seat of the same. FIG. 10D is a cross-sectional view taken along line XX of FIG. 10A. FIG. 11 is a cross-sectional perspective view of a main part of the same head model. FIG. 12 is a front view of the same head model with the headset attached. FIG. 13 is a flowchart of a program executed by the microcontroller in the evaluation device of the same. FIG. 14 is a block diagram showing a configuration of an evaluation system according to another embodiment of the present disclosure. FIG. 15 is a perspective view of the load receiving seat in the same as above.

Each figure described in the following embodiments is a schematic view, and the size, thickness, and ratio of each component do not always reflect the actual dimensions. The configuration described in the following embodiments is only an example of the present disclosure. The present disclosure is not limited to the following embodiments, and various changes can be made depending on the design and the like as long as the effects of the present disclosure can be achieved.

In explaining the evaluation system according to the present embodiment, the brain activity measuring device to be evaluated by the evaluation system will be described. As shown in FIG. 1, the brain activity measuring device (hereinafter referred to as a headset 1) constitutes the brain wave measuring system 10 together with the information processing device 2.

The electroencephalogram measurement system 10 is a system for measuring the electroencephalogram of the subject 5, and is an electroencephalogram from an electrode portion 11 arranged at a position corresponding to a measurement point 51 which is a part of the head 52 of the subject 5. Get information. The "electroencephalogram" (EEG) referred to in the present disclosure means a waveform obtained by deriving an electrical signal (action potential) emitted by a nerve cell (group) of the cerebrum to the outside of the body and recording it. In the present disclosure, unless otherwise specified, scalp electroencephalograms are recorded by using an electrode portion 11 attached to the scalp, targeting the overall action potentials of a large number of neurons (nerve network) in the cerebral cortex. It is called "brain wave".

The electroencephalogram measurement system 10 includes a headset 1 (see FIG. 3B) having an electrode portion 11 and an information processing device 2. The headset 1 is attached to the head 52 of the subject 5 in a state where the electrode portion 11 is in contact with the surface (scalp) of the head 52 of the subject 5. In the present disclosure, the electrode portion 11 comes into contact with the surface of the head 52 by being placed on a paste (electrode glue) applied to the surface of the head 52. At this time, the electrode portion 11 comes into contact with the surface of the head 52 without passing through the hair by scraping the hair. Of course, the electrode portion 11 may come into direct contact with the surface of the head portion 52 without applying the paste. That is, in the present disclosure, "contacting the electrode portion 11 with the surface of the head 52" means that the electrode portion 11 is in direct contact with the surface of the head 52 (including the scalp), and also via an intermediate. It also includes indirectly contacting the electrode portion 11 with the surface of the head 52. The intermediate is not limited to the paste, and may be, for example, a conductive gel.

The headset 1 measures the electroencephalogram of the subject 5 by measuring the action potential of the brain of the subject 5 at the electrode unit 11, and generates electroencephalogram information representing the electroencephalogram. The headset 1 transmits brain wave information to the information processing device 2 by, for example, wireless communication.

The information processing device 2 mainly includes a computer system such as a personal computer. The information processing device 2 receives the electroencephalogram information from the headset 1 by, for example, wireless communication, performs various processes on the electroencephalogram information acquired from the headset 1, and displays the electroencephalogram information. In the present embodiment, detection of brain waves including characteristic changes that occur when the subject 5 performs a voluntary movement (that is, that may occur when the subject 5 intends to perform a voluntary movement), and The calibration process and the like are performed by the information processing apparatus 2. The "calibration process" referred to in the present disclosure is a process for analyzing brain wave information, that is, for determining various parameters used for detecting a brain wave to be detected.

Next, the headset 1 will be described with reference to FIGS. 1, 3A and 3B. It should be noted that the arrows "D1" and "D2" shown in the drawings are shown only for the sake of explanation and are not accompanied by an entity.

The headset 1 includes a frame 17, a mounting portion 19, and a pair of holding portions 18. The frame 17 can be attached to the head 52 of the subject 5, and is attached to the head 52 in a first direction from the median center (vertex) of the subject 5 toward the left tragus and the right tragus. It has a shape extending to D1. The "center of the midline" referred to in the present disclosure is the position represented by the electrode symbol "Cz" in the International 10-20 Law, and in the head 52 of the subject 5, the nose root and the occipital nodule of the subject 5 This is the intersection of the line connecting the two and the line connecting the front point of the tragus of the left ear 521 and the front point of the tragus of the right ear 522. Further, in the "first direction" referred to in the present disclosure, in a state where the frame 17 is attached to the head 52, the midline center, the left tragus, and the right tragus of the subject 5 are connected along the head 52. The direction is parallel to the curve.

The mounting portion 19 is provided on the frame 17 and can accommodate the electrode portion 11 used for collecting the brain waves of the subject 5. The electrode portion 11 comes into contact with the position corresponding to the measurement point 51 on the surface of the head 52 with the frame 17 attached to the head 52. The frame 17 is provided with a pair of mounting portions 19.

The pair of holding portions 18 are connected to both ends of the first direction D1 of the frame 17, and come into contact with the head 52 with the frame 17 attached to the head 52. In other words, holding portions 18 are provided at both ends of the first direction D1 of the frame 17. Then, these holding portions 18 hold the frame 17 with respect to the head 52 by contacting the head 52 with the frame 17 attached to the head 52.

The above-mentioned electroencephalogram measurement system 10 is used, for example, in the rehabilitation support system 100 shown in FIG.

The rehabilitation support system 100 is a system for supporting the rehabilitation of the subject 5 by using the electroencephalogram measurement system 10 including the headset 1. The rehabilitation support system 100 supports rehabilitation by exercise therapy, for example, for a person who suffers from motor paralysis or deterioration of motor function in a part of the body due to a brain disease such as a stroke or an accident. In such a subject 5, the voluntary movement, which is an exercise performed by the subject 5 based on his / her own intention or intention, may not be satisfactory due to inability or deterioration of its function. The "exercise therapy" referred to in the present disclosure refers to a disorder caused by exercising a part of the body of the subject 5 in which such voluntary movement is impossible or a function is deteriorated (hereinafter referred to as "disordered part"). It means a method of recovering the function of voluntary movement for a part.

As shown in FIGS. 1 and 2, the rehabilitation support system 100 includes an electroencephalogram measurement system 10 (including a headset 1), an exercise assist device 3, and a control device 4.

The exercise assist device 3 is a device that assists the exercise of the subject 5 by adding at least one of a mechanical stimulus and an electrical stimulus to the subject 5. Since the rehabilitation support system 100 is used for the rehabilitation of the left finger of the subject 5, the exercise assist device 3 is attached to the left hand of the subject 5 as shown in FIG.

The rehabilitation support system 100 described below is used for rehabilitation of the gripping motion and the extension motion of the subject 5 with the left finger. The "grasping operation" referred to in the present disclosure means an operation of grasping an object. Further, the "extension motion" referred to in the present disclosure is grasped by the motion of opening the hand by extending the four fingers 53 (second to fifth fingers) excluding the first finger (thumb), that is, by the gripping motion. It means the action of releasing the "thing" of the state. That is, in the subject 5, the left finger is the impaired part, and the rehabilitation support system 100 is used for rehabilitation for voluntary movements such as gripping motion and extension motion by the left finger. However, in reality, the rehabilitation support system 100 does not directly assist the gripping motion of the subject 5, but indirectly rehabilitates the gripping motion by assisting the extension motion of the fingers of the subject 5. Do.

Therefore, in the rehabilitation support system 100, when the subject 5 intends to perform an extension movement as a voluntary movement, the exercise assist device 3 attached to the left hand of the subject 5 is mechanically attached to the left finger 53 of the subject 5. Assist voluntary movements by adding at least one of the stimuli and the electrical stimuli. That is, the rehabilitation support system 100 assists the voluntary movement (extension movement) when the subject 5 releases the peg 101 by the extension movement of the fingers 53 from the posture in which the peg 101 (see FIG. 1) is grasped by the left finger. .. However, not limited to this example, the rehabilitation support system 100 may be used for rehabilitation of the right finger of the subject 5, for example.

As shown in FIG. 2, the exercise assisting device 3 includes a finger driving device 31 and an electrical stimulation generator 32.

The finger driving device 31 holds four fingers 53 (second to fifth fingers) excluding the first finger (thumb), and applies mechanical stimulation (external force) to these four fingers 53. It is a device that moves four fingers 53. The finger driving device 31 includes, for example, a power source such as a motor or a solenoid, and moves the four fingers 53 by transmitting the force generated by the power source to the four fingers 53. In the finger driving device 31, the held four fingers 53 are moved in a direction away from the first finger (that is, an extension motion) and a movement (that is, a gripping motion) in a direction approaching the first finger. Two types of operations, "closing operation" and "closing operation", are possible. The opening operation of the finger driving device 31 assists the extension operation of the subject 5, and the closing operation of the finger driving device 31 assists the gripping operation of the subject 5.

The electrical stimulus generator 32 is a device that gives an electrical stimulus to a portion for moving the finger 53 of the subject 5. Here, the part for moving the finger 53 of the subject 5 includes a part corresponding to at least one of the muscle and the nerve of the finger 53 of the subject 5. For example, the part for moving the finger 53 of the subject 5 is a part of the arm of the subject 5. The electrical stimulation generator 32 includes, for example, a pad attached to the body (for example, an arm) of the subject 5. The electric stimulus generator 32 gives a stimulus to a part for moving the finger 53 by applying an electric stimulus (current) to the body of the subject 5 from the pad.

The control device 4 controls the exercise assist device 3 based on the electroencephalogram information acquired by the electroencephalogram measurement system 10. In other words, the control device 4 controls the exercise assist device 3 according to the brain waves of the subject 5 collected by the electrode portion 11 of the headset 1. The control device 4 is electrically connected to the information processing device 2 and the exercise assist device 3 of the electroencephalogram measurement system 10. A power cable for supplying the operation assisting device 3 and the operating power of the control device 4 is connected to the control device 4. The control device 4 includes a drive circuit for driving the finger drive device 31 of the exercise assist device 3 and an oscillation circuit for driving the electrical stimulation generator 32. The control device 4 receives a control signal from the information processing device 2 by, for example, wired communication.

When the control device 4 receives the first control signal from the information processing device 2, the control device 4 drives the finger drive device 31 of the exercise assist device 3 by the drive circuit, and the finger drive device 31 performs the "open operation". Controls the exercise assist device 3. Further, when the control device 4 receives the second control signal from the information processing device 2, the drive circuit drives the finger drive device 31 of the exercise assist device 3, and the finger drive device 31 performs a "closing operation". The exercise assist device 3 is controlled so as to be processed. Further, when the control device 4 receives the third control signal from the information processing device 2, the control device 4 drives the electrical stimulation generator 32 of the motion assisting device 3 by the oscillation circuit, and the body of the subject 5 is electrically stimulated. The exercise assist device 3 is controlled so as to be given.

In this way, the control device 4 controls the exercise assist device 3 based on the control signal output from the electroencephalogram measurement system 10, and the exercise assist device 4 is based on the electroencephalogram information acquired by the electroencephalogram measurement system 10. It is possible to control 3. Further, the control device 4 controls the exercise assist device 3 so that the finger drive device 31 performs the “open operation” and the “close operation” in response to the operation of the operation switch provided in the control device 4. You can also.

For example, in the same manner as when a medical staff such as a physical therapist or an occupational therapist holds the finger 53 of the subject 5 to assist the voluntary movement of the subject 5, the rehabilitation support system 100 assists the voluntary movement. It will be possible. Therefore, according to the rehabilitation support system 100, it is possible to realize rehabilitation by exercise therapy, which is more effective than the case where the subject 5 performs voluntary exercise alone, as in the case where the medical staff assists.

By the way, in order to support the rehabilitation as described above, the rehabilitation support system 100 may assist the voluntary movement of the subject 5 with the exercise assist device 3 when the subject 5 intends to perform the voluntary movement. desirable. The rehabilitation support system 100 is an exercise assist device 3 that matches the voluntary movement of the subject 5 by interlocking the exercise assist device 3 with the brain waves (electroencephalogram information) of the subject 5 measured by the brain wave measurement system 10. Achieve the assistance of voluntary movements. In other words, the rehabilitation support system 100 uses the brain-machine interface (BMI) technology to operate the machine (exercise assist device 3) using brain activity (brain waves). Achieve therapeutic rehabilitation.

When the subject 5 performs a voluntary movement (that is, in the process of the subject 5 performing a voluntary movement), characteristic changes in brain waves can occur. That is, when the subject 5 intends (remembers) to perform the voluntary movement, activation of the brain region corresponding to the target portion of the voluntary movement may occur. An example of such a brain region is the somatosensory motor cortex. More effective rehabilitation can be expected by assisting the voluntary movement of the subject 5 with the exercise assisting device 3 at the timing when such activation of the brain region occurs. Such activation of brain regions can be detected as characteristic changes in EEG. Therefore, the rehabilitation support system 100 assists the voluntary movement of the subject 5 with the exercise assist device 3 at the timing when this characteristic change occurs in the brain wave of the subject 5. Such a characteristic change can occur when the subject 5 images the voluntary movement (that is, during an exercise attempt) even if the voluntary movement is not actually performed. In other words, such characteristic changes in EEG can be seen if the corresponding brain region is activated by the intention (remembering) of the subject 5 to perform the voluntary movement even if the voluntary movement is not actually performed. Can occur. Therefore, the rehabilitation support system 100 can assist the voluntary movement even for the subject 5 who cannot perform the voluntary movement.

The electroencephalogram measurement system 10 detects an intensity change in a specific frequency band caused by an event-related desynchronization (ERD) as a characteristic change. The "event-related desynchronization" referred to in the present disclosure means a phenomenon in which the power of a specific frequency band decreases in an electroencephalogram measured near the motor cortex during voluntary movement (including recall of voluntary movement). The term "at the time of voluntary movement" as used in the present disclosure means a process from the time when the subject 5 intends (remembers) the voluntary movement to the success or failure of the voluntary movement. "Event-related desynchronization" can occur during this voluntary movement, triggered by the intention (recollection) of the voluntary movement. The frequency bands in which the power is reduced due to event-related desynchronization are mainly α waves (for example, frequency bands of 8 Hz or more and less than 13 Hz) and β waves (for example, frequency bands of 13 Hz or more and less than 30 Hz).

According to the rehabilitation support system 100 having such a configuration, it is possible to realize effective rehabilitation by exercise therapy in the subject 5 while reducing the burden on the medical staff. Further, according to the rehabilitation support system 100, for example, the timing of assisting the voluntary movement does not vary due to human factors such as the skill level of the medical staff who assists the voluntary movement of the subject 5, and the effect of the rehabilitation varies. Is reduced. In particular, in the rehabilitation support system 100, it is possible to assist the voluntary movement of the subject 5 at the timing when the characteristic change in the brain wave occurs (that is, the timing when the brain region is actually activated). As described above, in the rehabilitation support system 100, since training can be performed in accordance with the timing of brain activity, it can be expected to contribute to learning and establishment of correct brain activity. In particular, it is difficult for the subject 5 and the medical staff alone to determine whether or not a characteristic change has occurred in the brain wave. Therefore, by using the rehabilitation support system 100, effective rehabilitation that is difficult to realize only by the subject 5 or the medical staff becomes possible.

As shown in FIGS. 3A and 3B, the headset 1 includes a main body 15, a frame 17, and an electrode portion 11. The main body 15 has a box shape, and has a signal processing unit 12, a communication unit 13, and a battery 14 inside (see FIG. 2). The headset 1 is battery-powered, and operating power for the signal processing unit 12, the communication unit 13, and the like is supplied from the battery 14.

The electrode portion 11 is an electrode for collecting an electroencephalogram (electroencephalogram signal) of the subject 5, and is, for example, a silver-silver chloride electrode. The electrode portion 11 may be silver, gold, platinum or the like. The electrode portion 11 has a first electrode 111 and a second electrode 112. As shown in FIG. 3B, the measurement points 51 set on the surface of the head 52 of the subject 5 include the first measurement point 511 and the second measurement point 512. The first electrode 111 is an electrode corresponding to the first measurement point 511 and is arranged on the first measurement point 511. The second electrode 112 is an electrode corresponding to the second measurement point 512 and is arranged on the second measurement point 512. Specifically, the first measurement point 511 and the second measurement point 512 are first from the midline center side (upper side) on the line connecting the midline center of the head 52 and the tragus front point of the right ear 522. The measurement points 511 and the second measurement points 512 are arranged side by side in this order. That is, in the present disclosure, each of the first electrode 111 and the second electrode 112 corresponds to a contact portion where the brain activity measuring device (headset 1) contacts the head 52 in order to measure the brain activity (electroencephalogram). To do.

When the subject 5 intends (remembers) to perform a voluntary movement, an electroencephalogram including a characteristic change is usually generated in the motor cortex corresponding to the part of the body in which the voluntary movement is performed. Therefore, the electroencephalogram measurement system 10 measures the electroencephalogram collected from the vicinity of the motor cortex corresponding to the injured site, which is the target of rehabilitation. Here, the motor cortex corresponding to the left finger is in the right brain of the subject 5, and the motor cortex corresponding to the right finger is in the left brain of the subject 5. Therefore, when the left finger 53 of the subject 5 is targeted for rehabilitation, it is acquired by the electrode portion 11 (first electrode 111 and second electrode 112) in contact with the right side of the head 52 of the subject 5. The electroencephalogram to be measured is the object to be measured by the electroencephalogram measuring system 10. That is, as shown in FIG. 3B, the electrode portion 11 (first electrode 111 and second electrode 112) is arranged on the measurement point 51 formed of a part of the right surface of the head 52 of the subject 5. As an example, the electrode portion 11 (first electrode 111 and second electrode 112) is arranged at a position represented by the electrode symbol “C4” in the International 10-20 Law. When the right finger of the subject 5 is to be rehabilitated, the measurement point consisting of a part of the left surface of the head 52 of the subject 5, for example, the electrode symbol "C3" in the International 10-20 Law. The electrode portion 11 (first electrode 111 and second electrode 112) is arranged at the represented position.

Further, the headset 1 further includes a reference electrode 113 and a ground electrode 114. The reference electrode 113 is an electrode for measuring the reference potential of the electroencephalogram signal measured at each of the first electrode 111 and the second electrode 112. The reference electrode 113 is located at the posterior position of either the left ear 521 or the right ear 522 on the head 52. Specifically, the reference electrode 113 is arranged at the rear position of the ear on the side of the head 52 where the first electrode 111 and the second electrode 112 are arranged. In the illustrated example, since the first electrode 111 and the second electrode 112 are arranged on the right surface of the head 52, the reference electrode 113 is arranged at the rear position of the right ear 522. The ground electrode 114 is arranged at the rear position of the left ear 521 or the right ear 522 of the head 52 where the reference electrode 113 is not arranged. Since the reference electrode 113 is located posterior to the right ear 522, the ground electrode 114 is located posterior to the left ear 521. Each of the reference electrode 113 and the ground electrode 114 is electrically connected to the main body 15 of the headset 1 by an electric wire 16 and is attached to the surface (scalp) of the head 52. The position where the reference electrode 113 and the ground electrode 114 are arranged may be the earlobe, not the position behind the ear as described above. The posterior position of the ear and the earlobe are places in the head that are not easily affected by bioelectric potentials derived from brain activity. That is, it is preferable that the reference electrode 113 and the ground electrode 114 are arranged in a place on the head that is not easily affected by the bioelectric potential derived from brain activity.

The signal processing unit 12 is electrically connected to the electrode unit 11 and executes signal processing on the electroencephalogram signal (electrical signal) input from the electrode unit 11 to generate electroencephalogram information. The brain wave signal includes a voltage signal which is a potential difference between the potential of the first electrode 111 and the potential of the reference electrode 113, and a voltage signal which is a potential difference between the potential of the second electrode 112 and the potential of the reference electrode 113. .. That is, the headset 1 measures the electroencephalogram of the subject 5 by measuring the action potential of the brain of the subject 5 at the electrode unit 11, and generates the electroencephalogram information representing the electroencephalogram at the signal processing unit 12. The signal processing unit 12 includes at least an amplifier that amplifies the brain wave signal and an A / D converter that performs A / D conversion, and outputs the amplified digital brain wave signal as brain wave information.

The communication unit 13 has a communication function with the information processing device 2. The communication unit 13 transmits at least the brain wave information generated by the signal processing unit 12 to the information processing device 2. In the present embodiment, the communication unit 13 can communicate with the information processing device 2 in both directions. The communication method of the communication unit 13 is, for example, wireless communication based on Bluetooth (registered trademark) or the like. From the communication unit 13, brain wave information is transmitted to the information processing device 2 at any time.

The frame 17 has a horseshoe shape (in other words, an Alice band shape). That is, the frame 17 has a shape extending from the center of the midline toward the left tragus and the right tragus in the first direction D1 when attached to the head 52. The frame 17 is composed of a strip-shaped metal plate long in the first direction and a resin cover that covers at least a part of the metal plate. The frame 17 has flexibility. Therefore, by bending the frame 17, it is possible to widen the distance between both ends of the first direction D1 of the frame 17. Therefore, when the frame 17 is attached to the head 52, the head 52 is passed between both ends of the first direction D1 of the frame 17 by appropriately bending the frame 17 according to the size of the head 52. Is possible.

The main body 15 is attached to the central portion of the frame 17 in the first direction D1. Here, as shown in FIG. 3A, the main body 15 has an opening for confirming whether the main body 15 is arranged at an appropriate position with respect to the median center portion when the frame 17 is attached to the head 52. A section 151 is provided. The opening 151 penetrates the main body 15 in a direction intersecting (orthogonal) with both the first direction D1 and the second direction D2. For example, when the headset 1 is attached to the head 52 of the subject 5, the medical staff arranges the main body 15 at a position where the central center of the head 52 can be visually recognized through the opening 151 of the main body 15. , It is possible to adjust the mounting position of the headset 1.

Holding portions 18 are connected to both ends of the first direction D1 of the frame 17. In other words, in a state where the frame 17 is attached to the head 52, the holding portion 18 is connected to one end of the frame 17 on the left tragus side and one end on the right tragus side, respectively. The holding portion 18 is configured to be movable with respect to the frame 17 along the first direction D1. That is, the distance between the holding portion 18 and one end of the frame 17 in the first direction D1 is adjustable.

As shown in FIG. 3B, the holding portion 18 has a base portion 18A and a pad 18B. Both the base portion 18A and the pad 18B are curved so as to be along the head portion 52 when the frame 17 is attached to the head portion 52.

The base portion 18A has a long flat rectangular parallelepiped shape in the second direction D2 and is connected to the frame 17. One end of the base 18A in the second direction D2 (here, one end on the occipital nodule side of the head 52) has a larger size in the first direction D1 than the other parts of the base 18A. A hook-and-loop fastener is provided at a portion of the base portion 18A facing the head portion 52.

The pad 18B has a long flat rectangular parallelepiped shape in the second direction D2 and is attached to the base 18A. The pad 18B is located between the base 18A and the head 52 with the frame 17 attached to the head 52, and comes into contact with the head 52. The pad 18B is made of urethane resin, for example, and has a lower hardness than the base 18A. Therefore, when the pad 18B comes into contact with the head 52 while the frame 17 is attached to the head 52, the pad 18B sandwiched between the headset 1 and the head 52 is deformed, and the head set 1 to the head The force applied to 52 is reduced.

A hook-and-loop fastener is attached to a portion of the pad 18B facing the base portion 18A. Then, the pad 18B is attached to the base 18A by connecting the hook-and-loop fastener of the pad 18B to the hook-and-loop fastener 18D of the base 18A. In this way, the pad 18B is removable from the base 18A.

A pair of hooking portions 184 are provided at both ends of the holding portion 18 in the second direction D2. The hook portion 184 is formed in a hook shape, and is configured so that one end of the band is hooked. The band has a long shape along the circumferential direction (second direction D2) of the head 52 and has elasticity. The band is attached to the head 52 by hooking both ends thereof on the hooking portions 184 on the frontal side and / or the occipital side of the pair of holding portions 18, respectively. By wearing the band, the headset 1 is firmly fixed by the head 52. Therefore, it is possible to prevent the headset 1 from being displaced due to a change in the posture of the subject 5.

The frame 17 is further provided with a pair of mounting portions 19. The pair of mounting portions 19 are provided on both sides of the main body 15 in the first direction D1. At least one of the pair of mounting portions 19 has a first electrode 111 and a second electrode 112. In the present embodiment, of the pair of mounting portions 19, the mounting portion 19 on the right ear 522 side of the subject 5 has the first electrode 111 and the second electrode 112.

The mounting portion 19 has a base 190, a first case 191 and a second case 192, and a handle 193. The base 190 has a shape that sandwiches the frame 17 in the second direction D2. The base 190 is configured to be movable in the first direction D1 along the frame 17. Therefore, by adjusting the position of the base 190 with respect to the frame 17 in the first direction D1, the positions of the electrode portions 11 (first electrode 111 and second electrode 112) can be adjusted as a result.

The handle 193 is provided on the base 190. The handle 193 is used to selectively switch between a state in which the base 190 is fixed to the frame 17 and a state in which the base 190 is movable with respect to the frame 17. Specifically, by tightening the handle 193, the base 190 is fixed to the frame 17, and by loosening the handle 193, the base 190 is movable with respect to the frame 17.

The first case 191 and the second case 192 are both tubular bodies having an elliptical bottom. In the first case 191, the first bottom portion (bottom portion facing the head portion 52) is attached to the base 190, and the first electrode 111 and the second electrode 112 are held inside. The first end (one end facing the head 52) of each of the first electrode 111 and the second electrode 112 protrudes from the first case 191. Both the first electrode 111 and the second electrode 112 are configured to be movable relative to the first case 191 so that the amount of protrusion from the first case 191 can be changed. A coil spring is housed in the first case 191. The coil spring is arranged between the second end of the first electrode 111 and the second electrode 112 and the second bottom portion (bottom portion opposite to the first bottom portion) of the first case 191. One end of the coil spring is fixed to the bottom of the first case 191.

The first end (one end facing the head 52) of the second case 192 is open, and the outer shape of the second case 192 when viewed from the normal direction of the surface (scalp) of the head 52 is larger than that of the first case 191. .. The second case 192 is combined with the first case 191 so as to house a part of the first case 191 inside through the opening. The second case 192 is configured to be movable relative to the first case 191 between the first position and the second position in the direction in which the coil spring expands and contracts. At the first position, the amount of protrusion of the first case 191 from the second case 192 is the minimum, and at the second position, the amount of protrusion of the first case 191 from the second case 192 is the maximum. The first end of the shaft penetrating the second bottom of the first case 191 is fixed to the inner bottom of the second end (one end opposite to the first end) of the second case 192. The second end of the shaft is fixed to the first electrode 111 and the second electrode 112. Therefore, by moving the second case 192 between the first position and the second position with respect to the first case 191, the first electrode 111 and the second electrode 112 are moved along with the movement of the second case 192 and the shaft. Also move. That is, by moving the second case 192 with respect to the first case 191, it is possible to adjust the amount of protrusion of the first electrode 111 and the second electrode 112 from the first case 191.

Further, the second case 192 is configured to be movable in the second direction D2 with respect to the first case 191 at the second position. Then, by moving the second case 192 in the second direction D2 at the second position, the first end of the second case 192 is hooked on the second bottom of the first case 191. Here, when the second case 192 is moved from the first position to the second position by pulling the second case 192, the first electrode 111 and the second electrode 112 move to the inside of the first case 191. The coil spring is compressed. Then, when the pulling force of the second case 192 is released, the first electrode 111 and the second electrode 112 return to their original states due to the elastic force of the coil spring. On the other hand, when the second case 192 is hooked on the first case 191 as described above, the movement of the second case 192 from the second position to the first position is restricted, so that the coil spring is maintained in a compressed state. be able to. That is, in this case, the state in which the first electrode 111 and the second electrode 112 have moved inward of the first case 191 can be maintained.

When the headset 1 is attached to the head 52 of the subject 5, each of the first electrode 111 and the second electrode 112 is maintained in a state of being pushed by the head 52 and moved inward of the first case 191. To. That is, each of the first electrode 111 and the second electrode 112 pushes the measurement point 51 of the head 52 by the elastic force of the compressed coil spring. When measuring the brain waves of the subject 5 with the headset 1, it is desirable that the first electrode 111 and the second electrode 112 are brought into close contact with the scalp (measurement point 51). Therefore, in the headset 1, the first electrode 111 and the second electrode 112 are pressed against the scalp by the elastic force of the coil spring, thereby increasing the degree of adhesion between the first electrode 111 and the second electrode 112 and the scalp. However, if the elastic force of the coil spring is too strong, redness (erythema) is likely to occur at a portion of the head 52 where the first electrode 111 and the second electrode 112 are pressed. If the first electrode 111 and the second electrode 112 are pressed against the same location on the scalp for a long period of time, red blood cells may leak due to the rupture of blood vessels at the location, leading to pressure ulcers. Therefore, in the brain activity measuring device (headset 1), the brain activity (brain wave) is suppressed while suppressing redness caused by the members (first electrode 111 and second electrode 112) that come into contact with the scalp to measure the brain activity (brain wave). ) Is desired to be improved in measurement accuracy.

Therefore, the evaluation system 105 of the present embodiment indirectly measures the load applied by the first electrode 111 and the second electrode 112 of the headset 1 to the head 52 of the subject 5, and the measured value of the load is in an appropriate range. Judge (evaluate) whether or not it fits in. Hereinafter, the evaluation system 105 of the present embodiment will be described in detail with reference to FIGS. 4 to 12.

As shown in FIG. 4, the evaluation system 105 has a main body (head model 6) to which a brain activity measuring device (headset 1) can be attached, and a head model 6 provided on the head model 6 to convert a load into an electric signal 1. It includes one or more converters 7. The evaluation system 105 further includes an evaluation device 8. The evaluation device 8 evaluates the magnitude of the load by comparing the magnitude of the load obtained from the information on the load included in the electric signal with the reference value for evaluation.

The converter 7 includes a first converter 7A and a second converter 7B. The converter 7 is composed of a load cell using a strain gauge. As shown in FIG. 7, the converter 7 has a cylindrical main body 70 and a cable 71 drawn from the side surface of the main body 70. A protrusion 72 is provided in the center of the first bottom surface of the main body 70 (see FIG. 7). The main body 70 includes four strain gauges 73A to 73D and a strain generating portion that causes strain to be generated in each of the strain gauges 73A to 73D by a load applied to the protrusion 72 (see FIG. 5).

Each of the four strain gauges 73A to 73D housed in the main body 70 is arranged one by one on one of the four sides of the Wheatstone bridge circuit as shown in FIG. The cable 71 has four electric wires including two electric wires 711 and 712 for input and two electric wires 713 and 714 for output. The positive pole wire 711 for input is electrically connected to the connection points of the two strain gauges 73A and 73B, and the negative pole wire 712 for input is electrically connected to the connection points of the two strain gauges 73C and 73D. Has been done. The positive pole wire 713 for output is electrically connected to the connection points of the two strain gauges 73B and 73C, and the negative pole wire 714 for output is electrically connected to the connection points of the two strain gauges 73D and 73A. Has been done.

The evaluation device 8 includes a power feeding circuit 80, a signal processing circuit 81, and a microcontroller 82. The power supply circuit 80 converts, for example, an AC voltage supplied from a power system (commercial AC power supply) into a DC constant voltage, and the constant voltage (DC voltage) V1 is converted into a constant voltage (DC voltage) V1 via two electric wires 711 and 712. Power is supplied to the converter 7 (first converter 7A or second converter 7B) (see FIG. 5).

The signal processing circuit 81 is an amplifier circuit that amplifies the electric signal (voltage signal) V2 output from each converter 7 (first converter 7A or second converter 7B) via the two electric wires 713 and 714. It has an AD conversion circuit that AD-converts an electric signal amplified by an amplifier circuit. The AD conversion circuit inputs the converted digital signal to the input port of the microcontroller 82. The electric signal V2 output from the converter 7 has a voltage value corresponding to the amount of strain generated in each strain gauge 73A to 73D by the load applied to the converter 7. That is, it is possible to obtain the magnitude (unit: Newton) of the load applied to the converter 7 from the voltage value of the electric signal V2.

The microcontroller 82 is configured as a semiconductor integrated circuit in which a processor, a memory, peripheral devices, and the like are integrated into one chip. The microcontroller 82 can perform various processes by causing the processor to execute a program stored in the memory. Peripheral devices include input ports for signal input, output ports for signal output, timers, and the like. When the peripheral device includes an AD conversion circuit, the electric signal (the signal obtained by amplifying the electric signal V2 by the amplifier circuit) is AD-converted by the AD conversion circuit of the microcontroller 82 instead of the AD conversion circuit of the signal processing circuit 81. You may. The processing executed by the microcontroller 82 will be described later.

The head model 6 has a substantially elliptical columnar lower head 60 and an upper head 61 mounted on the upper bottom surface of the lower head 60. The upper head 61 is formed in a dome shape (more specifically, a semi-elliptical shape) which is a shape simulating a human head. The lower head 60 and the upper head 61 are preferably integrally formed of a material such as synthetic resin that can be easily molded. The dimensions of each part of the head model 6 are published in, for example, "Japanese body size data book 2004-2006 Publisher: Human Life Engineering Research Center". It is preferable to calculate from the dimensional data of the Japanese head. However, in the evaluation system 105 of the present embodiment, there are three types of head models: a large size head model 6, a medium size head model 6, and a small size head model 6. 6 is used. In the three types of head models 6 in the present embodiment, the head length S1 (see FIG. 8B), the head width S2 (see FIG. 8B), the tragus spacing S3 (see FIG. 8A), and the total head height S4 (see FIG. 8C). , And the intertragusal parietal arc length S5 (see FIG. 8A) are shown in Table 1 below. However, the values of the respective dimensions of S1 to S5 shown in Table 1 are merely examples, and it is preferable that the values are appropriately changed according to various conditions such as race, age, and gender.

Here, on the upper head 61, a circular first mark 610 is marked at a position corresponding to the center of the center of the person (see FIGS. 6 and 8B). Further, on the lower head 60, a circular second mark 600 is marked at each position corresponding to the left and right tragus of the person (see FIGS. 6 and 8C). The first mark 610 and the second mark 600 serve as marks when the headset 1 is attached to the head model 6 as will be described later. However, for the first mark 610 and the second mark 600, at least one mark needs to be marked on the head model 6, and both the first mark 610 and the second mark 600 are necessarily marked on the head model 6. You don't have to.

Further, in the shape of the upper head 61, the position corresponding to the center of the center of the person (the position indicated by the first mark 610) and the position corresponding to the pair of tragus of the person (the position indicated by each second mark 600) are set. The first curve W1 passing through is rotationally symmetric (twice symmetric) about the position corresponding to the center of the median (see FIG. 10A). The first curve W1 coincides with the intertragusal parietal arc. Further, in the shape of the upper head 61, the second curve W2 orthogonal to the first curve W1 through the position corresponding to the midline center is rotationally symmetric (twice symmetric) about the position corresponding to the midline center. ) (See FIG. 10B). Considering that the shape of the actual human head is generally symmetrical in the left-right direction and the front-back direction, if the upper head 61 has a rotationally symmetric (twice-symmetric) shape as described above, the upper head Compared with the case where the shape is not symmetrical, the manufacturing cost of the head model 6 (mainly the manufacturing cost of the mold) can be reduced.

In the upper head 61, one recess 62 is provided in each portion between the first mark 610 and the two second marks 600 (see FIG. 7). These two recesses 62 are formed to have the same shape and the same dimensions (however, in FIG. 7, only the recess 62 on one side is shown). The bottom surface of each recess 62 is a flat surface having the shape of a quadrangle (so-called rounded quadrangle) with four vertices rounded. A plurality of support protrusions 620 for supporting each of the two converters 7 (first converter 7A and second converter 7B) are provided on the bottom surface of each recess 62. However, in FIG. 7, only the four support protrusions 620 that support the first transducer 7A are shown, and the four support protrusions that support the second transducer 7B are hidden in the load receiving seat 64 (described later). ..

Each of the four support protrusions 620 supporting the first transducer 7A is formed in an arc shape and projects from the bottom surface of the recess 62 so as to be arranged at equal intervals. The main body 70 of the first converter 7A is fitted into the space surrounded by the four support protrusions 620, so that the first converter 7A is supported by the four support protrusions 620 (see FIG. 7). The second converter 7B is also fitted and supported in the space surrounded by the four support protrusions in the same manner as the first converter 7A. The cable 71 of the converters 7 (first converter 7A and second converter 7B) is pulled out of each lead-out groove 621 so as to crawl the bottom surface of the recess 62 to the outside of the recess 62.

The main body 70 of the converter 7 (first converter 7A and second converter 7B) is covered with a load receiving seat 64. As shown in FIGS. 10A to 10D, the load receiving seat 64 has a main portion 640 and a collar portion 641. It is preferable that the main portion 640 and the collar portion 641 are integrally formed of a synthetic resin material. The main portion 640 is formed in a prismatic shape having a first bottom surface 6401 and a second bottom surface 6402 having rounded square shapes. The second bottom surface 6402 is a flat surface, while the first bottom surface 6401 is a curved surface that is convex in a direction away from the second bottom surface 6402. Further, the normal direction D3 of the first bottom surface 6401 is inclined with respect to the normal direction D4 of the second bottom surface 6402 (see FIG. 10D). It should be noted that the arrows "D3" and "D4" shown in FIG. 10D are shown only for the sake of explanation and are not accompanied by an entity.

A circular mating recess 642 is provided in the center of the second bottom surface 6402 of the main portion 640. The main body 70 of the converter 7 fits into the mating recess 642 (see FIG. 11). Further, a circular recess 643 is provided in the center of the bottom surface of the mating recess 642. The protrusion 72 of the converter 7 fits into the recess 643 (see FIG. 11). Further, the second bottom surface 6402 is provided with a semi-cylindrical groove 644 extending from the edge of the mating recess 642 to the edge of the collar portion 641 (see FIG. 10C). The cable 71 of the converter 7 is passed through the groove 644.

The head model 6 has two covers 63 that block each of the two recesses 62, as shown in FIGS. 6 and 7. However, in FIGS. 6 and 7, only one cover 63 corresponding to one recess 62 is shown.

The shape of the cover 63 when viewed from the thickness direction is the same rounded quadrangle as the bottom surface of the recess 62. The back surface of the cover 63 (the surface facing the bottom surface of the recess 62) is flat like the bottom surface of the recess 62 (see FIG. 11). On the other hand, the surface of the cover 63 (the surface exposed on the surface of the upper head 61) is formed in the same curved surface (surface of the ellipsoid) as the surface of the upper head 61 (see FIGS. 8A and 8B).

The cover 63 has two through holes (first through hole 630A and second through hole 630B) penetrating in the thickness direction of the cover 63. Further, a storage recess 631 is provided on the back surface of the cover 63. These two through holes (first through hole 630A and second through hole 630B) have openings in the bottom surface of the accommodating recess 631. The accommodation recess 631 accommodates the first transducer 7A and the second transducer 7B and the two load receiving seats 64 (see FIG. 11). Each of the two load receiving seats 64 fits into the main body 70 of each of the first converter 7A and the second transducer 7B. The main portion 640 of each load receiving seat 64 is passed through one of the through holes (first through hole 630A and second through hole 630B) opened in the bottom surface of the accommodating recess 631 and facing one of the through holes. .. Further, the main portion 640 of each load receiving seat 64 is displaceably supported by the cover 63 along the thickness direction of the cover 63 (the same direction as the arrow of D4 in FIG. 10D) (see FIG. 11).

Four screw insertion holes 633 are provided at the four corners of the cover 63 (see FIG. 7). Each screw insertion hole 633 penetrates the cover 63 in the thickness direction. Then, the cover 63 has one fixing screw 65 inserted into each screw insertion hole 633, and one corresponding screw fixing hole of the screw fixing holes 622 provided at the four corners of the bottom surface of the recess 62. It is fixed to the upper head 61 by being screwed into 622 (see FIG. 6). A pair of notches (first notch 632A and second notch 632B) are provided on one side of the cover 63. The first notch 632A and the second notch 632B are connected to the storage recess 631 on the back surface of the cover 63. Then, the cable 71 of the first converter 7A is pulled out of the recess 62 from the space (hole) surrounded by the first notch 632A of the cover 63 and one of the lead-out grooves 621 of the recess 62. Similarly, the cable 71 of the second converter 7B is pulled out of the recess 62 from the space (hole) surrounded by the second notch 632B of the cover 63 and the other lead-out groove 621 of the recess 62.

Each surface of the main portion 640 of the two load receiving seats 64 is exposed to the surface of the cover 63 through one of the corresponding through holes 630A and 630B of the first through hole 630A and the second through hole 630B of the cover 63. (See FIG. 6). Then, when a load in the direction from the load receiving seat 64 toward the transducer 7 is applied to the load receiving seat 64 (main portion 640), the load receiving seat 64 becomes a through hole (first through hole 630A and second through hole 630A) of the cover 63. The inside of the through hole 630B) is displaced in a direction approaching the converter 7. Then, the main portion 640 of the load receiving seat 64 pushes the protrusion 72 of the converter 7 toward the main body portion 70. That is, of the loads applied to the load receiving seat 64, the load in the direction D5 parallel to the axial direction (thickness direction of the cover 63) of the first through hole 630A and the second through hole 630B is applied to the protrusion 72 of the converter 7. (See FIG. 11). Therefore, the converter 7 converts a component (load) parallel to the direction D5 in the load applied to the load receiving seat 64 into an electric signal V2, and conducts electricity via the cable 71 (two electric wires 713, 714). The signal V2 can be output. It should be noted that the arrow “D5” shown in FIG. 11 is shown only for the sake of explanation and is not accompanied by an entity.

Next, a method of evaluating the brain activity measuring device (headset 1) by the evaluation system 105 of the present embodiment (evaluation method of the present embodiment) will be described.

First, a person who evaluates the headset 1 (hereinafter referred to as an evaluator) attaches the frame 17 of the headset 1 to the upper head 61 of the head model 6 of any size (for example, S size). To do. At this time, the evaluator adjusts the mounting position of the frame 17 with respect to the upper head 61 so that the first mark 610 of the head model 6 can be visually recognized through the opening 151 of the main body 15. It can be mounted at an appropriate position on the model 6. Then, the evaluator moves each of the pair of left and right mounting portions 19 with respect to the frame 17, and makes each of the first electrode 111 and the second electrode 112 of each mounting portion 19 the main portion of the corresponding load receiving seat 64. It is brought into contact with the surface of 640 (see FIG. 12). At this time, a load is applied to each load receiving seat 64 from the first electrode 111 and the second electrode 112.

Subsequently, the evaluator electrically connects the two electric wires 711 and 712 of the cable 71 of the first converter 7A and the cable 71 of the second converter 7B to the power supply circuit 80 of the evaluation device 8. Further, the evaluator electrically connects the two electric wires 713 and 714 of the cable 71 of the first converter 7A and the cable 71 of the second converter 7B to the signal processing circuit 81 of the evaluation device 8. Then, the evaluator causes the microcontroller 82 of the evaluation device 8 to execute the program for evaluation (the program of the present embodiment). The microcontroller 82 performs a process for evaluating the load applied to the head 52 from the first electrode 111 and the second electrode 112 of the headset 1 according to the evaluation program. It is preferable that the microcontroller 82 reads and executes an evaluation program recorded on a non-temporary recording medium such as a semiconductor memory, a magnetic disk, or an optical disk.

Next, the process performed by the microcontroller 82 according to the evaluation program will be described with reference to the flowchart of FIG.

First, the microcontroller 82 initializes the subscript i of the array L (i) to 1 (Step 1). Subsequently, the microcontroller 82 substitutes the data (value corresponding to the magnitude of the load) read from the digital signal of the signal processing circuit 81 into the array L (i) (Step 2). The microcontroller 82 compares the subscript i with the specified value N (for example, N = 12) (Step 3), and if the subscript i is less than the specified value N, increments the subscript i (Step 4) and steps. Return to 2. Further, if the subscript i is the specified value N or more, the microcontroller 82 sorts the N arrays L (1) to L (N) in ascending order according to the size of the variable (data) (Step 5). .. The microcontroller 82 has N / 2 arrays L (i) excluding the first N / 4 and the trailing N / 4 of the N arrays L (1) to L (N) sorted in ascending order. , ... Arithmetic mean LM is calculated (Step 6).

Subsequently, the microcontroller 82 compares the arithmetic mean LM with the reference value TH (Step 7). Here, the reference value TH aims to improve the measurement accuracy of the brain activity (electroencephalogram) of the subject 5 while suppressing the redness that occurs at the measurement point 51 of the subject 5 based on the results of tests conducted in advance. It is preferable that the value is set to a possible value. For example, the reference value TH in this embodiment is less than 1N (Newton) in terms of the magnitude of the load applied from the electrode portion 11 (first electrode 111 and second electrode 112) to the measurement point 51 of the subject 5. Is set to a value of (preferably 0.9N). The reference value TH is stored in the memory of the microcontroller 82.

If the arithmetic mean LM is less than the reference value TH, the microcontroller 82 determines that the magnitude of the load of the electrode portion 11 is good (determination result OK) (Step 8). If the arithmetic mean LM is equal to or greater than the reference value TH, the microcontroller 82 determines that the magnitude of the load of the electrode portion 11 is defective (determination result NG) (Step 9). The microcontroller 82 notifies the evaluator of the determination result (evaluation result) of the arithmetic mean LM. For example, the microcontroller 82 notifies the evaluator of the evaluation result by displaying the evaluation result on a display device such as a liquid crystal display provided in the evaluation device 8. Alternatively, the microcontroller 82 may drive a speaker or buzzer provided in the evaluation device 8 and notify the evaluator of the evaluation result by sound (voice message or buzzer sound).

The evaluator can determine the quality (pass / fail) of the load of the electrode unit 11 in the headset 1 to be evaluated based on the evaluation result notified from the evaluation device 8. If the evaluator determines that the result is unacceptable, it is desirable that the headset 1 to be evaluated undergoes a design change such as a change in the spring constant of the coil spring.

The operation of the evaluation system described above (process executed by the microcontroller 82 according to the program) is only an example. Further, the evaluation device 8 (microcontroller 82) performs the final evaluation of the headset 1, and the evaluation device 8 notifies the evaluator of the magnitude of the load measured by the converter 7, and the notification is given. Based on this, the evaluator may make a final evaluation of the headset 1. Further, an acquisition unit (a device having the same configuration as the evaluation device 8) that processes the electric signal V2 output from the converter 7 and acquires the load information (load magnitude) included in the electric signal V2 is provided. It may be built in the head model 6.

In the present embodiment, as the brain activity measuring device to be evaluated, a headset 1 configured to measure an electroencephalogram by an electroencephalogram electrode (electrode portion 11) in contact with the head 52 is illustrated, but the evaluation target The brain activity measuring device is not limited to the headset 1. The evaluation system 105 of the present embodiment may include, for example, a functional near-infrared spectroscope as an evaluation target as a brain activity measuring device other than the headset 1. The functional near-infrared spectroscope includes a light emitting device that emits near-infrared light and a photoelectric conversion device that receives near-infrared light and converts it into an electric signal. A functional near-infrared spectroscope brings a light-emitting device and a photoelectric conversion device into contact with the scalp, irradiates the brain with the near-infrared light of the light-emitting device, and reflects the near-infrared light (reflected light) on the brain surface of the cerebral cortex. ) Is photoelectrically converted by a photoelectric conversion device to measure the blood flow state (brain activity) on the brain surface of the cerebral cortex. That is, in the functional near-infrared spectroscope, the light emitting device and the photoelectric conversion device correspond to the contact portion, and the evaluation system 105 may evaluate the pressing force (load) applied to the scalp by the light emitting device and the photoelectric conversion device. ..

By the way, in addition to the load of the electrode portion 11, it is desired that the electrical characteristics of the electrode portion 11 be an evaluation item of the headset 1. In evaluating the electrical characteristics of the electrode unit 11, if the above-mentioned work of evaluating the load of the electrode unit 11 and the work of evaluating the electrical characteristics of the electrode unit 11 can be performed simultaneously or continuously, it is possible. The work load of the evaluator can be reduced.

FIG. 14 shows a system configuration example of the evaluation system 106 for evaluating the electrical characteristics of the electrode portion 11 of the headset 1 using the head model 6 in the evaluation system of the present embodiment.

The evaluation system 106 includes a multifunction generator 107 and a pseudo-electroencephalogram generation circuit 108. The multifunction generator 107 is configured to generate, for example, a reference voltage having an arbitrary frequency in the frequency range of 1 Hz or less to several tens of Hz. In the evaluation system 106 of the present embodiment, it is preferable to generate a reference voltage of two kinds of frequencies, 9 Hz and 18 Hz, in the multifunction generator 107. 9 Hz is the frequency band of the α wave, and 18 Hz is the frequency band of the β wave. That is, the waveforms of the two types of reference voltages generated by the multifunction generator 107 simulate the brain wave waveforms of the two types of brain waves (α wave and β wave).

The pseudo electroencephalogram generation circuit 108 has an attenuator 1080 and two impedance units (first impedance unit 1081 and second impedance unit 1082). The attenuator 1080 is configured to reduce (attenuate) the amplitude of the reference voltage while maintaining the frequency of the reference voltage supplied from the multifunction generator 107.

The attenuator 1080 has four signal lines 1083-1086. Each of the two signal lines 1083, 1084 of the four signal lines 1083-1086 is electrically connected to the corresponding electrode plate 66 of the two electrode plates 66, one by one. As shown in FIG. 15, the electrode plate 66 is preferably provided on the main portion 640 of the load receiving seat 64 of the head model 6. The electrode plate 66 is made of, for example, a metal plate material, and is insert-molded into the main portion 640 so that one surface is exposed on the surface of the main portion 640. That is, the first electrode 111 and the second electrode 112 of the electrode portion 11 are among the electrode plates 66 of the load receiving seats 64 attached to the main body portions 70 of the first converter 7A and the second converter 7B. Contact and conduct with the corresponding electrode plate 66.

Further, each of the remaining two signal lines 1085 and 1086 of the four signal lines 1083 to 1086 are electrically connected to the corresponding terminal portions 67 and 68 of the two terminal portions 67 and 68 one by one. To. Each of the terminal portions 67, 68 has, for example, an alligator clip and is electrically connected to the corresponding one of the reference electrode 113 and the ground electrode 114 via the alligator clip.

The first impedance unit 1081 has two resistors. One of the two resistors is electrically connected in series to the signal line 1083 and the electrode plate 66 which is in contact with and conducts with the first electrode 111. The remaining one of the two resistors is electrically connected in series to the signal line 1084 and the electrode plate 66 which is in contact with and conducts with the second electrode 112. It is preferable that the resistance values of the two resistors of the first impedance portion 1081 are substantially equal to the resistance values of the contact resistance between the human scalp and the electrode portion 11.

The second impedance section 1082 has two resistors. One of the two resistors is electrically connected in series to the signal line 1085 and one terminal 67. The remaining one of the two resistors is electrically connected in series to the signal line 1086 and the other terminal 68. It is preferable that the resistance values of the two resistors of the second impedance portion 1082 are substantially equal to the resistance values of the contact resistance between the human scalp and the reference electrode 113 and the ground electrode 114.

Next, a method of evaluating the electrical characteristics of the electrode portion 11 of the headset 1 by the evaluation system 106 will be described.

The evaluator causes the pseudo-electroencephalogram generation circuit 108 to supply a reference voltage of a predetermined evaluation pattern from the multifunction generator 107 while evaluating the pressing force of the electrode unit 11 described above. The evaluation pattern includes, for example, a waveform pattern in which the amplitude of a reference voltage simulating an α wave is increased or decreased at regular time intervals (for example, 5 seconds), and a reference voltage amplitude simulating a β wave for a certain period of time (for example, 5 seconds). It is a waveform pattern that increases or decreases every 5 seconds). That is, the multifunction generator 107 supplies the pseudo-brain wave generation circuit 108 with a reference voltage that simulates the brain wave when event-related desynchronization (ERD) occurs. The pseudo-electroencephalogram generation circuit 108 adjusts (amplifies) the reference voltage supplied from the multifunction generator 107 to the electrode portion 11 of the headset 1 via the two electrode plates 66 and the two terminal portions 67 and 68. Output to the reference electrode 113 and the ground electrode 114. That is, the pseudo brain wave is supplied to the electrode portion 11 of the headset 1 through the electrode plate 66 of the head model 6.

The headset 1 transmits the electroencephalogram information of the pseudo electroencephalogram to the information processing device 2. The information processing device 2 displays brain wave information (for example, a brain wave waveform) of a pseudo brain wave received from the headset 1 on a display device of a computer system. Based on the electroencephalogram information displayed on the display device, the evaluator can evaluate the electrical characteristics of the electrode unit 11 based on whether or not a change corresponding to the evaluation pattern appears in the electroencephalogram waveform of the electroencephalogram information. it can. When the evaluator determines (evaluates) that the electrical characteristics of the electrode unit 11 are rejected, it is desirable that the cause of the failure is investigated and improved for the headset 1 to be evaluated. .. The evaluation work of the electrical characteristics of the electrode portion 11 may be performed before or after the evaluation work of the load of the electrode portion 11. As described above, according to the evaluation system 106 of the present embodiment, the evaluator can simultaneously or continuously perform the respective operations of the evaluation of the load on the electrode portion 11 and the evaluation of the electrical characteristics. As a result, the evaluation system 106 can reduce the work load of the evaluator.

As described above, the evaluation system (105) of the brain activity measuring device (headset 1) according to the first aspect of the present disclosure is the head of the subject (5) in order to measure the brain activity of the subject (5). A brain activity measuring device having a contact portion (electrode portion 11) for contacting the portions includes a main body (head model 6) that can be attached in a state where the contact portions are in contact with each other. The evaluation system (105) of the brain activity measuring device according to the first aspect includes a converter (7) provided in the main body and converting a load into an electric signal. The converter (7) is arranged in a portion of the main body that receives a load from the contact portion with the brain activity measuring device attached to the main body.

In the evaluation system (105) according to the first aspect, the load received from the contact portion is converted into an electric signal by the converter (7) provided in the main body, so that the magnitude of the load received from the contact portion is converted into an electronic circuit (computer). (Including the system) makes it easier to handle. Therefore, the evaluation system (105) of the brain activity measuring device according to the first aspect can easily and appropriately evaluate the load applied to the head (52) of the subject (5) from the brain activity measuring device.

The evaluation system (105) according to the second aspect of the present disclosure can be realized in combination with the first aspect. In the evaluation system (105) according to the second aspect, a load receiving seat (64) is provided which is arranged between the converter (7) and the contact portion and applies a load received from the contact portion to the converter (7). Is preferable. The surface of the load receiving seat (64) that comes into contact with the contact portion is preferably formed in a curved surface shape that is convex in the direction approaching the contact portion.

In the evaluation system (105) according to the second aspect, the surface of the load receiving seat (64), which is the surface receiving the load from the contact portion, can be shaped to be close to the surface of the actual head (52). .. As a result, the evaluation system (105) according to the second aspect can improve the measurement accuracy of the load received from the contact portion.

The evaluation system (105) according to the third aspect of the present disclosure can be realized in combination with the first or second aspect. In the evaluation system (105) according to the third aspect, it is preferable to include a plurality of converters (7). Each of the plurality of converters (first converter 7A, second converter 7B) corresponds to a plurality of contact portions (first electrode 111, second electrode 112) of the brain activity measuring device in the main body. It is preferably arranged at a portion that receives a load from one contact portion.

In the evaluation system (105) according to the third aspect, the loads of the plurality of contact portions (first electrode 111, second electrode 112) are individually applied by a plurality of converters (first converter 7A, second converter 7B). Can be converted into an electrical signal. As a result, the evaluation system (105) according to the third aspect can shorten the time required for evaluation as compared with the case where the load of the plurality of contact portions is converted into an electric signal by one converter. ..

The evaluation system (105) according to the fourth aspect of the present disclosure can be realized by combining with any one of the first to third aspects. In the evaluation system (105) according to the fourth aspect, the converter (7) is configured to convert a load in a direction parallel to the direction in which the contact portion applies a load to the head into an electric signal. preferable.

The evaluation system according to the fourth aspect can improve the reliability of evaluation by measuring the load from the contact portion more accurately.

The evaluation system (105) according to the fifth aspect of the present disclosure can be realized by combining with any one of the first to fourth aspects. In the evaluation system (105) according to the fifth aspect, the position corresponding to the median center of the subject (5) and the tragus of the subject (5) in a part (upper head 61) including the part of the main body. It is preferable that a mark (first mark 610, second mark 600) is provided at at least one of the corresponding positions.

In the evaluation system (105) according to the fifth aspect, the brain activity measuring device can be attached to an appropriate position of the main body by using the marks (first mark 610, second mark 600).

The evaluation system (105) according to the sixth aspect of the present disclosure can be realized by combining with any one of the first to fifth aspects. In the evaluation system (105) according to the sixth aspect, the position corresponding to the median center of the subject (5) and the position corresponding to the tragus on both sides of the subject (5) are set in a part including the part of the main body. It is preferable that the first curve (W1) passing through is rotationally symmetric with respect to the position corresponding to the center of the median. Further, the second curve (W2) orthogonal to the first curve (W1) passes through the position corresponding to the median center in a part including the part of the main body, and rotates about the position corresponding to the median center. It is preferably symmetrical.

The evaluation system (105) according to the sixth aspect can reduce the manufacturing cost of the main body as compared with the case where a part including the part of the main body does not have a symmetrical shape.

The evaluation system (105) according to the seventh aspect of the present disclosure can be realized by combining with any one of the first to sixth aspects. In the evaluation system (105) according to the seventh aspect, an acquisition unit (signal processing circuit 81) that processes the electric signal output from the converter (7) and acquires the load information included in the electric signal is further added. It is preferable to prepare.

In the evaluation system (105) according to the seventh aspect, the wiring work between the converter (7) and the acquisition unit (signal processing circuit 81) can be omitted.

The evaluation system (105) according to the eighth aspect of the present disclosure can be realized by combining with any one of the first to seventh aspects. In the evaluation system (105) according to the eighth aspect, the evaluation device (8) that evaluates the magnitude of the load by comparing the magnitude of the load obtained from the information of the load contained in the electric signal with the reference value for evaluation. It is preferable to provide.

The evaluation system (105) according to the eighth aspect can reduce the burden on the evaluator who performs the evaluation work by providing the evaluation device (8).

The evaluation system (106) according to the ninth aspect of the present disclosure can be realized by combining with any one of the first to eighth aspects. In the evaluation system (106) according to the ninth aspect, it is preferable to further include a generating unit (electrode plate 66) that simulates generating a signal detected by the contact unit for measuring brain activity. It is preferable that the generating portion is arranged at a portion of the main body where the converter (7) is arranged, and a signal is simulated in a state where the converter (7) receives a load from the contact portion.

The evaluation system (106) according to the ninth aspect can evaluate the load of the contact portion and the electrical characteristics of the contact portion.

The evaluation method of the brain activity measuring device according to the tenth aspect of the present disclosure is for the brain activity measuring device to measure the brain activity by using the converter (7) provided in the main body to which the brain activity measuring device can be attached. Place it in the part that receives the load from the contact part that comes into contact with the head. Further, in the evaluation method according to the tenth aspect, the load received by the portion from the contact portion is converted into an electric signal by the converter (7).

In the evaluation method according to the tenth aspect, the load applied to the head (52) of the subject (5) from the brain activity measuring device can be easily and appropriately evaluated.

The evaluation method according to the eleventh aspect of the present disclosure can be realized in combination with the tenth aspect. In the evaluation method according to the eleventh aspect, it is preferable to evaluate the load magnitude by comparing the load magnitude obtained from the load information included in the electric signal with the reference value for evaluation.

In the evaluation method according to the eleventh aspect, the load applied to the head (52) of the subject (5) can be easily evaluated from the brain activity measuring device.

The program according to the twelfth aspect of the present disclosure causes a computer system (microcontroller 82) to execute an evaluation method of a brain activity measuring device.

The program according to the twelfth aspect can easily and appropriately evaluate the load applied to the head (52) of the subject (5) from the brain activity measuring device.

The non-temporary recording medium according to the thirteenth aspect of the present disclosure is read by a computer system in which a program for causing the computer system to execute the evaluation method of the brain activity measuring device according to the tenth or eleventh aspect is recorded. It is a possible non-temporary recording medium.

The non-temporary recording medium according to the thirteenth aspect can easily and appropriately evaluate the load applied to the head (52) of the subject (5) from the brain activity measuring device.

1 Headset (brain activity measuring device)
6 Head model (main body)
7 Converter 7A 1st converter 7B 2nd converter 8 Evaluation device 11 Electrode part 60 Lower head 61 Upper head 64 Load receiving seat 66 Electrode plate 81 Signal processing circuit 82 Microcontroller (computer)
105 Evaluation system 106 Evaluation system 111 1st electrode 112 2nd electrode 600 2nd mark (mark)
610 1st mark (mark)
W1 1st curve W2 2nd curve

Claims (13)

A main body that can be worn by a brain activity measuring device having a contact portion that contacts the subject's head in order to measure the subject's brain activity in contact with the contact portion.
A converter provided in the main body for converting a load into an electric signal is provided.
The converter is an evaluation system for a brain activity measuring device that is arranged at a portion of the main body that receives a load from the contact portion with the brain activity measuring device attached to the main body. A load receiving seat arranged between the transducer and the contact portion and applying a load received from the contact portion to the converter is provided.
The evaluation system for the brain activity measuring device according to claim 1, wherein the surface of the load receiving seat that comes into contact with the contact portion is formed in a curved surface shape that is convex in a direction approaching the contact portion. Equipped with a plurality of the converters
Claim 1 or 2 in which each of the plurality of transducers is arranged in a portion of the main body that receives a load from the corresponding one of the plurality of contact portions of the brain activity measuring device. The evaluation system of the described brain activity measuring device. Any one of claims 1 to 3, wherein the converter is configured to convert a load in a direction parallel to a direction in which the contact portion applies a load to the head into an electric signal. Evaluation system of the brain activity measuring device described in. Claims 1 to 4 in which a mark is provided at at least one of a position corresponding to the center of the subject and a position corresponding to the tragus of the subject in a part including the portion of the main body. The evaluation system for the brain activity measuring device according to any one of the above. Through a first curve that passes through a position corresponding to the center of the subject and a position corresponding to the tragus on both sides of the subject in a part including the portion of the main body, and a position corresponding to the crown. The evaluation of the brain activity measuring device according to any one of claims 1 to 5, wherein the first curve and the second curve orthogonal to the first curve are rotationally symmetric with respect to the position corresponding to the center of the midline. system. Evaluation of the brain activity measuring apparatus according to any one of claims 1 to 6, further comprising an acquisition unit that processes an electric signal output from the converter to acquire information on a load included in the electric signal. system. The item according to any one of claims 1 to 7, further comprising an evaluation device for evaluating the magnitude of the load by comparing the magnitude of the load obtained from the information of the load included in the electric signal with the reference value for evaluation. The evaluation system of the described brain activity measuring device. Further provided is a generator that simulates a signal detected by the contact to measure brain activity.
Any of claims 1 to 8, wherein the generating portion is arranged at a portion of the main body where the converter is arranged, and the signal is simulated in a state where the converter receives a load from the contact portion. The evaluation system for the brain activity measuring device described in item 1. A converter provided in the main body to which the brain activity measuring device can be attached is arranged at a portion that receives a load from a contact portion that the brain activity measuring device contacts the head in order to measure the brain activity, and the portion is the said An evaluation method of a brain activity measuring device that converts a load received from a contact portion into an electric signal by the converter. The evaluation method for a brain activity measuring device according to claim 10, wherein the magnitude of the load is evaluated by comparing the magnitude of the load obtained from the information of the load included in the electric signal with a reference value for evaluation. A program for causing a computer system to execute the evaluation method of the brain activity measuring device according to claim 11. A non-temporary recording medium readable by the computer system, which records a program for causing the computer system to execute the evaluation method of the brain activity measuring device according to claim 10 or 11.

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