WO2019163375A1 - Biosignal measurement device, electroencephalograph, and control method - Google Patents

Abstract

A biosignal measurement device (10b) comprising: a first pulse generator (56a) that outputs a first trigger pulse; a first amplification circuit (52a) to which a biosignal detected by a first electrode in contact with a living body is input; and a first capacitive element (59a) for superimposing the first trigger pulse on the biosignal, that capacitively couples an output terminal of the first pulse generator (56a) and an input terminal of the first amplification circuit (52a).

Description

Biological signal measuring apparatus, electroencephalograph, and control method

The present invention relates to a biological signal measuring device, an electroencephalograph, a control method, and the like.

A biological signal measuring apparatus that measures a subject's brain wave or heart rate as a biological signal is known. As an example of such a biological signal measuring apparatus, Patent Document 1 discloses an evoked waveform calculation apparatus that obtains an evoked waveform by inputting biological information data such as an electroencephalogram, a brain magnetic field, and a myoelectric potential.

Japanese Patent Laid-Open No. 10-80409

The present invention provides a biological signal measuring device, an electroencephalograph, a control method, and a program that can superimpose a pulse on a biological signal detected by an electrode that contacts the living body.

A biological signal measuring apparatus according to an aspect of the present invention includes a first pulse generator that outputs a first pulse, a first amplifier circuit that receives a biological signal detected by a first electrode that contacts the living body, And a first capacitive element for capacitively coupling the output terminal of the first pulse generator and the input terminal of the first amplifier circuit for superimposing the first pulse on the biological signal.

An electroencephalograph according to an aspect of the present invention includes the biological signal measuring device and a mounting portion that brings the first electrode into contact with the head of the living body.

The control method which concerns on 1 aspect of this invention is a control method of a biological signal measuring device, Comprising: The said biological signal measuring device is the 1st pulse generator which outputs a 1st pulse, and the 1st electrode which contacts a biological body. To superimpose the first pulse on the biological signal, capacitively coupling the first amplifier circuit to which the detected biological signal is input, the output terminal of the first pulse generator and the input terminal of the first amplifier circuit. And a switching element connected between the capacitive element and the input terminal of the first amplifier circuit, and the control method includes an operation in a first measurement mode for turning off the switching element, and By turning on the switch element, the operation in the second measurement mode in which the first pulse can be superimposed on the biological signal is performed.

The program according to an aspect of the present invention is a program for causing a computer to execute the control method.

The biological signal measuring apparatus, electroencephalograph, control method, and program of the present invention can superimpose a pulse on a biological signal.

FIG. 1 is an external view showing a configuration of a biological signal measurement system according to an embodiment. FIG. 2A is a diagram illustrating an example of the shape and schematic configuration of a headphone headset. FIG. 2B is a diagram illustrating an example of the shape and schematic configuration of a band-type headset. FIG. 3A is a diagram illustrating a first example of a shape of a contact surface of an electrode that comes into contact with a subject's skin. FIG. 3B is a diagram illustrating a second example of the shape of the contact surface of the electrode that contacts the skin of the subject. FIG. 3C is a diagram illustrating a third example of the shape of the contact surface of the electrode that contacts the skin of the subject. FIG. 3D is a diagram illustrating a fourth example of the shape of the contact surface of the electrode that contacts the skin of the subject. FIG. 3E is a diagram illustrating a fifth example of the shape of the contact surface of the electrode that contacts the skin of the subject. FIG. 4 is a block diagram showing the overall configuration of the biological signal measurement system according to the embodiment. FIG. 5 is a functional block diagram showing detailed configurations of the headset and the information processing apparatus. FIG. 6 is a block diagram showing a hardware configuration of the headset. FIG. 7 is a block diagram illustrating a hardware configuration of the information processing apparatus. FIG. 8 is a flowchart showing a flow of basic processing of the biological signal measurement system according to the embodiment. FIG. 9 is a circuit block diagram showing a detailed configuration of the biological signal measuring apparatus according to the embodiment. FIG. 10 is a diagram illustrating an example of a circuit configuration of the attenuation circuit. FIG. 11 is a diagram for explaining an example of using the first trigger pulse. FIG. 12 is a flowchart of an operation example of the biological signal measuring apparatus. FIG. 13 is a diagram illustrating a detailed configuration of the biological signal processing unit. FIG. 14 is a flowchart illustrating a display operation example of the biological signal measurement system according to the embodiment. FIG. 15 is a diagram illustrating a display example in the presentation unit in the second measurement mode. FIG. 16 is a diagram illustrating a display example on the presentation unit in the first measurement mode. FIG. 17 is a circuit block diagram showing a detailed configuration of a biological signal measuring apparatus according to a modification of the embodiment. FIG. 18A is a first schematic diagram illustrating an appearance of an active electrode. FIG. 18B is a second schematic diagram illustrating the appearance of the active electrode.

Hereinafter, embodiments will be specifically described with reference to the drawings. It should be noted that each of the embodiments described below shows a comprehensive or specific example. The numerical values, shapes, materials, constituent elements, arrangement positions and connecting forms of the constituent elements, steps, order of steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements.

Each figure is a schematic diagram and is not necessarily shown strictly. Moreover, in each figure, the same code | symbol is attached | subjected to substantially the same structure, and the overlapping description may be abbreviate | omitted or simplified.

(Embodiment)
[Outline of biological signal measurement system]
FIG. 1 is an external view showing a configuration of a biological signal measurement system 100 according to an embodiment. In FIG. 1, a subject 5 to be measured is also shown.

The biological signal measurement system 100 is a system that measures a biological signal of the subject 5 and includes a headset 10, an information processing device 20, and a presentation unit 30. The headset 10, the information processing device 20, and the presentation unit 30 are connected by wired communication or wireless communication, and transmit / receive information between the devices.

The headset 10 is an example of a device that detects a biological signal, and has a configuration of an electroencephalograph described later. A plurality of electrodes 51 (see FIGS. 2A and 2B) are attached to the head of the subject 5. The plurality of electrodes 51 includes a measurement electrode 51a that measures a biological signal and a reference electrode 51b that measures a reference potential used to calculate a difference between the potential measured by the measurement electrode. In addition, the headset 10 includes an operation input device 10a (see FIG. 5) in which the subject 5 inputs operation information to the biological signal measurement system 100, and an operation for realizing a desired process is input. The biological signal detection apparatus constituting the biological signal measurement system 100 is not limited to an electroencephalograph, but an electrocardiograph that detects an electrocardiogram signal (Electrocardiogram (ECG) signal) from electrodes attached to the body, hands, feet, and the like. It may be.

The information processing apparatus 20 receives an operation input from the headset 10 and performs a predetermined process. For example, the information processing apparatus 20 may be a computer. The “predetermined processing” here is a general term for applications such as games, health management, learning, and the like that are implemented on a home computer.

The presentation unit 30 is an output device that presents the results of processing performed by the information processing apparatus 20. “Present” here includes both displaying an image on a display and / or outputting sound from a speaker. That is, the presentation unit 30 is a display and / or a speaker that displays image information or outputs acoustic information.

[Headset configuration]
2A and 2B are diagrams illustrating an example of the shape and schematic configuration of the headset 10. FIG. 2A shows a headphone type headset, and FIG. 2B shows a band type headset. The subject 5 wears the headset 10 shown in FIGS. 2A and 2B on the head.

The headset 10 shown in FIG. 2A has an arched headphone shape along the head of the subject 5. The headset 10 shown in FIG. 2A includes a plurality of electrodes 51, a mounting portion 40, and an ear pad 46, as shown.

The mounting part 40 is an arch-shaped member provided with a plurality of electrodes 51 that is mounted on the head of the subject 5. The mounting portion 40 includes an operation surface 43, an outer surface 44, and a mounting surface 45. The outer side surface 44 is a surface that is disposed on the side opposite to the head of the subject 5 when the subject 5 wears the headset 10. The wearing surface 45 is a surface arranged on the head side of the subject 5 when the subject 5 wears the headset 10. The operation surface 43 includes operation buttons 41 and a display unit 47. The plurality of electrodes 51 are provided on the mounting surface 45 of the headset 10 and the end of the ear pad 46 on the same side as the mounting surface 45 of the headset 10.

The test subject 5 activates the headset 10 by operating the operation button 41 arranged on the operation surface 43 before wearing the headset 10, and then attaches the headset 10 to the head. The headset 10 is, for example, such that the left ear pad 46 is located on the right ear of the subject 5 toward the paper surface of FIG. 2A and the right ear pad 46 is located on the left ear of the subject 5 toward the paper surface of FIG. It is worn on the head of the subject 5. The ear pad 46 is applied so as to cover the left and right ears of the subject 5. The electrode 51 provided on the mounting surface 45 is applied to the skin (that is, the scalp) of the subject 5. The electrode 51 provided at the end of the ear pad 46 is applied behind the ear of the subject 5. The electrode 51 provided at the end of the left ear pad 46 toward the paper surface of FIG. 2A is a ground electrode described later, and the electrode 51 provided at the end of the right ear pad 46 toward the paper surface of FIG. The other electrode 51 may be a measurement electrode. The arrangement position of the ground electrode and the reference electrode is not limited to this, and the electrode 51 provided at the end of the right ear pad 46 toward the paper surface of FIG. 2A is used as a ground electrode, and the left side of the paper surface of FIG. The electrode 51 provided at the end of the ear pad 46 may be used as a reference electrode.

The operation surface 43 displays the operation state and the processing result of the application on the display unit 47.

The headset 10 shown in FIG. 2B has a band shape that is wound around the head of the subject 5 and attached. The band-type headset 10 includes a plurality of electrodes 51 and a mounting portion 40. The mounting part 40 is an annular member provided on the head of the subject 5 and provided with a plurality of electrodes 51. The mounting portion 40 includes an operation surface 43, an outer surface 44, and a mounting surface 45. The configuration of the electrode 51 and the operation surface 43 is the same as that of the headphone type headset 10 shown in FIG. 2A.

Before wearing the headset 10, the test subject 5 operates the operation button 41 arranged on the operation surface 43 to activate the headset 10, and then the half of the outer surface 44 of the band-type headset 10 (operation Wear so that the side of the surface 43 comes to the forehead of the subject 5. The electrode 51 is disposed on the mounting surface 45 and is in contact with the forehead of the subject 5. The electrode 51 corresponding to the ground electrode and the electrode 51 corresponding to the reference electrode among the plurality of electrodes 51 may be configured such that a lead wire (not shown) is extended from the mounting surface 45 and applied behind the ear. Good. The operation surface 43 is further provided with a display unit 47, which can display the operation state and the processing result of the application. Note that the earth electrode is not a ground electrode (an electrode having a ground potential) that is generally referred to, but an electrode having a potential that is a reference potential in the subject 5.

[Electrode shape]
3A to 3E are diagrams showing examples of the shape of the contact surface of the electrode 51 that comes into contact with the skin of the subject 5. FIG. The material of the electrode 51 is composed of a conductive substance. An example of the material of the electrode 51 is gold or silver. A desirable material for the electrode 51 is silver-silver chloride (Ag / AgCl). This is because silver-silver chloride has little polarization when in contact with a living body and the polarization voltage is stable.

The shape of the contact surface of the electrode 51 may be a circle (for example, a diameter of 10 mm) shown in FIG. 3A similar to the electrode used for medical purposes, or may have various shapes depending on the application. For example, it may be a triangle as shown in FIG. 3B or a quadrangle or a square as shown in FIG. 3C.

Further, as the electrode 51 disposed on the mounting surface 45 of the headphone type headset 10, as shown in FIG. 3D, an electrode 51 composed of a plurality of columns (five in the figure) may be used. According to this configuration, since the electrode 51 is brought into contact with the skin of the subject 5, the hair can be separated. In addition, the contact surface with the skin in each column may be circular as shown in FIG. 3D, or may be another shape such as an ellipse. Further, the shape of the electrode 51 is not limited to a cylinder, and may be a prism. The number of cylinders or prisms may be five as shown in FIG. 3D, not limited to five, and may be changed as appropriate. Moreover, the tip of each cylinder shown in FIG. 3D may have a shape with a rounded corner (that is, a roundness) on the side of the contact surface with the skin. Thereby, the contact area of each cylinder and skin can be increased.

Further, as shown in FIG. 3E, the shape of the electrode 51 may be an electrode 51 whose contact surface with the skin of the subject 5 is concentric. The electrode 51 having this shape is used, for example, in the ear pad 46 of the headphone type headset 10 shown in FIG. 2A or the band type headset 10 shown in FIG. 2B, and is brought into contact with a portion having no hair such as the forehead or behind the ear. . Since the electrode 51 having the shape shown in FIG. 3E has a reduced pressure on the skin as compared with the electrode 51 having the shape shown in FIG. 3D, the burden on the subject 5 is reduced.

[Configuration of biological signal measurement system]
FIG. 4 is a block diagram showing the overall configuration of the biological signal measurement system 100. As described above, the biological signal measurement system 100 includes the headset 10, the information processing device 20, and the presentation unit 30. The headset 10 includes an operation input device 10a and a biological signal measurement device 10b.

The headset 10 receives the operation input of the subject 5 in the operation input device 10a, and measures the biological signal of the subject 5 during the operation in the biological signal measurement device 10b. The biological signal measured by the headset 10 is transmitted to the information processing apparatus 20.

The information processing device 20 receives an input from the operation input device 10a or the biological signal measurement device 10b, performs a predetermined process, and outputs a processing result to the presentation unit 30. The headset 10 and the information processing apparatus 20 are connected by wireless communication or wired communication.

FIG. 5 is a functional block diagram showing detailed configurations of the headset 10 and the information processing apparatus 20. Here, a case where the headset 10 and the information processing apparatus 20 are connected by wireless communication will be described as an example.

The operation input device 10a includes an operation input unit 11 and an operation signal output unit 12.

The operation input unit 11 is an input device that acquires operation input information input from the operation button 41 (see FIGS. 2A and 2B) and determines the content of the operation. The operation signal output unit 12 is a transmitter that transmits the operation input information acquired by the operation input unit 11 to the information processing apparatus 20. The operation input information acquired by the operation input unit 11 is transmitted from the operation signal output unit 12 to the information processing apparatus 20.

The biological signal measuring device 10 b includes an electrode unit 13, a biological signal amplification unit 14, and a biological signal output unit 15.

The electrode unit 13 includes a plurality of electrodes 51. As described above, the plurality of electrodes 51 includes the measurement electrode and the reference electrode. The plurality of electrodes 51 are, for example, arranged at positions that come into contact with the skin of the subject 5.

The biological signal amplification unit 14 is an amplifier that amplifies a biological signal corresponding to a potential difference between the plurality of electrodes 51. Specifically, the biological signal amplification unit 14 includes a measurement electrode 51a (see FIG. 6) disposed on the skin of the subject 5 and a reference electrode 51b (behind the ear of the subject 5 among the plurality of electrodes 51). The potential difference is measured and the measured potential difference is amplified. The amplified potential difference is converted into a digital signal by an A / D converter (not shown) provided in the biological signal amplification unit 14, for example. The biological signal output unit 15 is a transmitter that transmits the potential difference amplified by the biological signal amplification unit 14 to the information processing apparatus 20. The potential difference of the biological signal converted into a digital value in the biological signal amplifier 14 is transmitted from the biological signal output unit 15 to the information processing device 20.

The biological signal amplifying unit 14 does not need to amplify the biological signal and may only measure the potentials of the plurality of electrodes 51 when a biological signal having a magnitude greater than or equal to a predetermined potential can be measured.

The information processing apparatus 20 includes an operation signal acquisition unit 21, a biological signal acquisition unit 22, a biological signal processing unit 23, an application processing unit (application processing unit) 26, a display information output unit 27, and an acoustic information output unit 28.

The information processing apparatus 20 receives information from the headset 10 by receiving operation input information at the operation signal acquisition unit 21 and receiving a biological signal at the biological signal acquisition unit 22.

Biosignals are often unusable as information with only recorded original signals. Therefore, the biological signal processing unit 23 performs processing for extracting meaningful information from the original signal. For example, in the case of electroencephalogram measurement, the biological signal processing unit 23 extracts a signal having a specific frequency (for example, 10 Hz), and calculates the power spectral density (Power Spectral Density) of the signal at the frequency. Note that the biological signal processing unit 23 may be disposed on the headset 10 side instead of the information processing apparatus 20. That is, in the present embodiment, an electronic device may be configured by the headset 10 and the biological signal processing unit 23.

The application processing unit 26 performs central application processing (application processing) of the information processing apparatus 20. The application process is realized by receiving a signal input from the headset 10 and performing a predetermined process. The predetermined processing includes, for example, game progress in the game app, recording / data management / display in the health management app, question / score / result display in the learning app, and the like.

The result processed by the application processing unit 26 is output from the application processing unit 26 to the display information output unit 27 and the acoustic information output unit 28. The display information output unit 27 and the acoustic information output unit 28 output visual or auditory signals to the presentation unit 30 in order to feed back the results processed by the application processing unit 26 to the subject 5.

The presentation unit 30 presents the signals output from the display information output unit 27 and the acoustic information output unit 28 (that is, displays and / or sounds). Thereby, a signal is presented to the subject 5. The presentation unit 30 is, for example, a television, a display, or a speaker.

[Hardset hardware configuration]
FIG. 6 is a block diagram illustrating a hardware configuration of the headset 10. The headset 10 includes an operation button group 71, a control signal conversion circuit 72, a measurement electrode 51a, a reference electrode 51b, a ground electrode 51c, a differential amplifier circuit 74, an A / D converter 75, a transmission circuit 79, a signal processing unit 78, an antenna. 80 and a battery 81.

Among these, the operation button group 71 and the control signal conversion circuit 72 correspond to the operation input unit 11 shown in FIG. Each button in the operation button group 71 corresponds to the operation button 41. The measurement electrode 51a, the reference electrode 51b, and the ground electrode 51c correspond to the electrode 51 shown in FIGS. 2A and 2B and the electrode portion 13 shown in FIG. The differential amplifier circuit 74 and the A / D converter 75 are included in the biological signal amplifier 14.

The signal processing unit 78 includes a CPU 101, a RAM 102, a program 103, and a ROM 104. Further, the transmission circuit 79 and the antenna 80 function as the biological signal output unit 15 and / or the operation signal output unit 12 illustrated in FIG. The transmission circuit 79 and the antenna 80 may be referred to as “output unit” or “transmitter”.

These components are connected to each other via a bus 105 and can exchange data with each other. The headset 10 operates using the battery 81 as a power source.

Information on pressing of each button related to the operation button group 71 is converted into a control signal for controlling the operation of the headset 10 in the control signal conversion circuit 72 and sent to the CPU 101 via the bus 105.

To the differential amplifier circuit 74, the measurement electrode 51a, the reference electrode 51b, and the ground electrode 51c are directly connected or connected via a buffer amplifier or the like. These electrodes are installed at predetermined locations of the headset 10. The potential difference between the measurement electrode 51a and the reference electrode 51b is amplified by the differential amplifier circuit 74, and converted from an analog biological signal to a digital biological signal by the A / D converter 75. The potential difference converted into a digital biological signal is sent to the CPU 101 via the bus 105 as a biological signal that can be processed and transmitted.

CPU 101 executes program 103 stored in RAM 102. The program 103 describes a signal processing procedure in the headset 10 shown in a flowchart of FIG. The headset 10 converts the operation signal and the biological signal into a digital signal according to the program 103 and transmits the digital signal from the antenna 80 via the transmission circuit 79. The program 103 may be stored in the ROM 104.

The signal processing unit 78, the control signal conversion circuit 72, the transmission circuit 79, the differential amplifier circuit 74, and the A / D converter 75 are a DSP (Digital Signal Processor) or the like in which a computer program is incorporated in one semiconductor integrated circuit. It may be realized as hardware. When mounted on one semiconductor integrated circuit, the mounting area can be reduced and the power consumption can be reduced.

Further, the differential amplifier circuit 74 and the A / D converter 75 are integrated in one semiconductor integrated circuit, and the signal processing unit 78, the control signal conversion circuit 72, and the transmission circuit 79 are integrated in another semiconductor integrated circuit. Two semiconductor integrated circuits may be connected in one package and integrated as a SiP (system in package), and may be realized as hardware such as a DSP incorporating a computer program. By realizing the two semiconductor integrated circuits by separate manufacturing processes, an effect of reducing the cost can be obtained as compared with the case where they are mounted on one semiconductor integrated circuit.

[Hardware configuration of information processing device]
FIG. 7 is a block diagram illustrating a hardware configuration of the information processing apparatus 20. The information processing apparatus 20 includes an antenna 83, a receiving circuit 82, a signal processing unit 108, an image control circuit 84, a display information output circuit 85, an acoustic control circuit 86, an acoustic information output circuit 87, and a power source 88. Among these components, the antenna 83 and the receiving circuit 82 correspond to the biological signal acquisition unit 22 and / or the operation signal acquisition unit 21 illustrated in FIG. These are sometimes called “receivers”.

The signal processing unit 108 includes a CPU 111, a RAM 112, a program 113, and a ROM 114. The signal processing unit 108 corresponds to the biological signal processing unit 23 and / or the application processing unit 26 illustrated in FIG. The image control circuit 84 and the display information output circuit 85 correspond to the display information output unit 27 shown in FIG. The acoustic control circuit 86 and the acoustic information output circuit 87 correspond to the acoustic information output unit 28 shown in FIG. These are connected to each other by a bus 115 and can exchange data with each other. Each circuit is supplied with power from a power supply 88.

Operation information and biological information from the headset 10 are received by the receiving circuit 82 via the antenna 83 and sent to the CPU 111 via the bus 115.

CPU 111 executes program 113 stored in RAM 112. The program 113 describes a signal processing procedure in the information processing apparatus 20 shown in a flowchart of FIG. The information processing apparatus 20 converts the operation signal and the biological signal according to the program 113, performs a process for executing a predetermined application, and generates a signal for performing feedback to the subject 5 by an image or sound. The program 113 may be stored in the ROM 114.

The image feedback signal generated by the signal processing unit 108 is output from the display information output circuit 85 to the presentation unit 30 via the image control circuit 84. Similarly, the acoustic feedback signal generated by the signal processing unit 108 is output from the acoustic information output circuit 87 via the acoustic control circuit 86.

The signal processing unit 108, the receiving circuit 82, the image control circuit 84, and the acoustic control circuit 86 may be realized as hardware such as a DSP in which a program is incorporated in one semiconductor integrated circuit. When one semiconductor integrated circuit is used, an effect of reducing power consumption can be obtained.

[Operation of biopotential measurement system]
Next, the operation of the biological signal measurement system 100 according to the present embodiment configured as described above will be described.

FIG. 8 is a flowchart showing a basic processing flow of the biological signal measurement system 100. Steps S11 to S14 indicate processing in the headset 10 (step S10), and steps S21 to S25 indicate processing in the information processing apparatus 20 (step S20).

First, the processing step S10 in the headset 10 will be described.

<Step S11>
The operation input unit 11 receives an operation input performed by the subject 5. Specifically, it is detected which operation button 41 is pressed at the reception timing. An example of the reception timing is when the operation button 41 is pressed. Whether or not the operation button 41 has been pressed is detected, for example, by detecting a mechanical button position change or an electrical signal change when the operation button 41 is pressed. Further, the operation input unit 11 detects the type of operation input received by the operation input unit 11 based on the type of the pressed operation button 41, and transmits it to the operation signal output unit 12.

<Step S12>
The operation signal output unit 12 transmits an operation signal corresponding to the operation input received by the operation input unit 11 to the information processing apparatus 20.

<Step S13>
The biological signal amplification unit 14 measures and amplifies a biological signal corresponding to the potential difference between the plurality of electrodes 51 in the electrode unit 13. For example, the potential difference between the measurement electrode 51a and the reference electrode 51b arranged on the right side of the plurality of electrodes 51 in the electrode part 13 (C4 electrode position in the international 10-20 method) is measured. Further, the biological signal amplifier 14 amplifies the measured biological signal. The amplified biological signal is transmitted from the biological signal amplifier 14 to the biological signal output unit 15.

<Step S14>
Furthermore, the biological signal output unit 15 transmits the transmitted biological signal to the information processing device 20.

In step S10 in headset 10, steps S11 and S12 and steps S13 and S14 may be performed in parallel, and the processes from step S11 to step S14 are all performed in the order described above. There is no need to do this.

Next, processing step S20 in the information processing apparatus 20 will be described.

<Step S21>
In the information processing apparatus 20, the operation signal acquisition unit 21 receives an operation signal from the operation signal output unit 12. The operation signal acquisition unit 21 transmits the received operation signal to the application processing unit 26.

<Step S22>
The biological signal acquisition unit 22 receives the biological signal from the biological signal output unit 15. The biological signal acquisition unit 22 transmits the received biological signal to the biological signal processing unit 23.

<Step S23>
The biological signal received by the biological signal acquisition unit 22 is analyzed by the biological signal processing unit 23 to extract meaningful information. For example, a biological signal having a predetermined frequency component is extracted. The predetermined frequency component is, for example, 10 Hz in the case of measuring an electroencephalogram.

<Step S24>
The application processing unit 26 receives an operation signal from the operation signal acquisition unit 21 and a biological signal from the biological signal processing unit 23, and performs a predetermined process for executing the current application. As described above, the predetermined processing includes, for example, game progress in the game app, recording / data management / display in the health management app, question / score / result display in the learning app, and the like.

<Step S25>
In order to feed back the processing result of the application processing unit 26 to the subject 5, the display information output unit 27 outputs video information to the presentation unit 30, and the acoustic information output unit 28 outputs acoustic information to the presentation unit 30. Thereby, the presentation unit 30 outputs an image and a sound corresponding to the processing result.

In addition, in process step S20 in the information processing apparatus 20, the process of step S22 and step S23, and step S24 may each be performed as a parallel process. The application processing unit 26 does not need to perform processing using both the operation signal from the operation signal acquisition unit 21 and the biological signal from the biological signal processing unit 23, and performs processing using only the biological signal. May be. In that case, step S21 for receiving the operation signal can be omitted.

The biological signal measurement system 100 can obtain biological information such as an electroencephalogram or an electrocardiogram from the subject 5 by the processing flow as described above.

[Detailed configuration of biological signal measuring apparatus]
Next, a detailed configuration of the biological signal measuring device 10b included in the headset 10 will be described. FIG. 9 is a circuit block diagram showing a detailed configuration of the biological signal measuring device 10b included in the headset 10. FIG. 9 shows a hardware configuration related to the biological signal measuring device 10b among the hardware configurations provided in the headset 10.

The biological signal measurement device 10b includes a measurement electrode 51a, a reference electrode 51b, a first amplification circuit 52a, a second amplification circuit 52b, a first high-pass filter 53a, a second high-pass filter 53b, a biological signal amplification unit 14, and a biological signal output unit 15. , The first pulse generator 56a, the first capacitive element 59a, the switch element S1, the control unit 60, and the operation button 41.

The first amplification circuit 52a is an amplifier to which a biological signal detected by the measurement electrode 51a that contacts the living body is input. The measurement electrode 51a is an example of a first electrode. The first amplifier circuit 52a functions as a so-called buffer amplifier and performs impedance conversion. The first amplifier circuit 52a does not perform voltage amplification (the voltage amplification factor is 1), but may perform voltage amplification. In this specification, the term “amplifier circuit” or “amplifier” is not necessarily limited to an amplifier having a voltage amplification factor larger than 1, and includes an amplification circuit or an amplifier having a voltage amplification factor of 1 or less. .

The second amplification circuit 52b is an amplifier to which a biological signal detected by the reference electrode 51b that contacts the living body is input. The reference electrode 51b is an example of a second electrode. The second amplifier circuit 52b functions as a so-called buffer amplifier and performs impedance conversion. The second amplifier circuit 52b does not perform voltage amplification (the voltage amplification factor is 1), but may perform voltage amplification.

The first high-pass filter 53a is a filter that removes unnecessary low-frequency components of the output signal from the first amplifier circuit 52a. The first high-pass filter 53a is, for example, a passive filter having a cutoff frequency of 0.5 Hz.

The second high-pass filter 53b is a filter that removes unnecessary low-frequency components of the output signal from the second amplifier circuit 52b. The second high-pass filter 53b is, for example, a passive filter having a cutoff frequency of 0.5 Hz.

The biological signal amplifier 14 includes a differential amplifier circuit 74, a low-pass filter 54, and an A / D converter 75.

The differential amplifier circuit 74 is an amplifier that amplifies a difference (that is, a potential difference) between the output signal CH1_in from the first high-pass filter 53a and the output signal Ref_in from the second high-pass filter 53b. In other words, basically, the differential amplifier circuit 74 amplifies the difference between the signal output from the first amplifier circuit 52a and the signal output from the second amplifier circuit 52b. Accordingly, the differential amplifier circuit 74 outputs a signal obtained by amplifying the potential at the measurement electrode 51a based on the potential at the reference electrode 51b as an amplified biological signal. The voltage amplification factor of the differential amplifier circuit 74 is 1200, for example.

The low-pass filter 54 is a filter that removes unnecessary high-frequency components of the output signal from the differential amplifier circuit 74. The low-pass filter 54 is an active filter having a cutoff frequency of 100 Hz, for example.

The A / D converter 75 is a converter that samples the output signal from the low-pass filter 54 and converts it into a digital signal. For example, the A / D converter 75 converts the output signal into a 12-bit digital signal at 1 kHz sampling.

The biological signal output unit 15 is a transmitter that transmits the potential difference amplified by the biological signal amplification unit 14 to the information processing device 20 as described above. The potential difference of the biological signal converted into a digital value by the A / D converter 75 of the biological signal amplification unit 14 is transmitted from the biological signal output unit 15 to the information processing device 20.

Incidentally, the biological signal measuring device 10b can superimpose the first trigger pulse on the biological signal detected by the measurement electrode 51a. Hereinafter, the first pulse generator 56a, the first capacitive element 59a, the switch element S1, and the control unit 60, which are components for superimposing the first trigger pulse, will be described.

The first pulse generator 56a outputs a first trigger pulse. The first trigger pulse is an example of the first pulse. Specifically, the first pulse generator 56a includes a generation circuit 57a and an attenuation circuit 58a.

The generation circuit 57a is an oscillation circuit that generates the original trigger pulse of the first trigger pulse. In other words, the trigger pulse is an instantaneous pulse. The trigger pulse is, for example, a triangular pulse, but may be a rectangular pulse, and the shape of the trigger pulse is not particularly limited.

The generation circuit 57a changes at least one of the amplitude and pulse width of the original trigger pulse based on, for example, an operation performed on the operation button 41. As a result, at least one of the amplitude and the pulse width of the first trigger pulse output from the first pulse generator 56a is changed. That is, the first pulse generator 56a can change at least one of the amplitude and pulse width of the first trigger pulse. Note that at least one of the amplitude and the pulse width of the first trigger pulse may be changed based on an operation on a user interface (not shown) included in the information processing apparatus 20.

The attenuation circuit 58a attenuates the original trigger pulse generated by the generation circuit 57a, and outputs a first trigger pulse obtained by attenuation of the original trigger pulse. FIG. 10 is a diagram illustrating an example of a circuit configuration of the attenuation circuit 58a.

As shown in FIG. 10, specifically, the attenuation circuit 58a is a voltage dividing circuit that divides the original trigger pulse by a resistor. The attenuation circuit 58a includes resistors R1 and R2 that divide the original trigger pulse, a capacitor C1 connected between the resistor R1 and the output terminal of the generation circuit 57a, and between the resistor R2 and the output terminal of the generation circuit 57a. And a capacitor C2 connected to.

The resistance value of the resistor R1 is, for example, 100 kΩ, and the resistance value of the resistor R2 is, for example, 10Ω. When the amplitude of the original trigger pulse is 100 mVp-p, the amplitude of the first trigger pulse is 10 μVp-p. The capacitance values of the capacitor C1 and the capacitor C2 are, for example, 47 μF.

The attenuation circuit 58a may be capable of changing the attenuation amount of the original trigger pulse. For example, the resistor R1 may be a variable resistor, and the attenuation amount of the attenuation circuit 58a may be changed by the user directly operating the variable resistor. The resistor R1 is a digital potentiometer, and the amount of attenuation may be changed based on a control signal output from the control unit 60.

The biological signal is a weak signal, and the trigger pulse output from a general signal generator has an amplitude that is too large to be superimposed on the biological signal. For this reason, the attenuation circuit 58a is useful.

Note that the first pulse generator 56a may be an interface circuit or a terminal that acquires the first trigger pulse from a signal generation device provided outside the biological signal measurement device 10b. That is, it is not essential that the first pulse generator 56a includes the generation circuit 57a and the attenuation circuit 58a.

The first capacitive element 59a capacitively couples the output terminal of the first pulse generator 56a and the input terminal of the first amplifier circuit 52a. The first capacitive element 59a is an element for superimposing the first trigger pulse on the biological signal. The capacitance value of the first capacitive element 59a is, for example, 100 pF.

The switch element S1 is connected between the input terminals of the first capacitor element 59a and the first amplifier circuit 52a. The switch element S1 switches presence / absence of electrical connection between the input terminals of the first capacitor element 59a and the first amplifier circuit 52a in accordance with the control signal CS1 output from the control unit 60. The switch element S1 is, for example, an FET (Field Effect Transistor), but may be another switch element. Although the switch element S1 may be omitted, if the switch element S1 is turned off when the first trigger pulse is not superimposed on the biological signal, the influence of the first pulse generator 56a on the biological signal is reduced. be able to.

The controller 60 switches the switch element S1 on and off by outputting the control signal CS1. In the following embodiments, an operation mode in which the first trigger pulse cannot be superimposed on the biological signal by turning off the switch element S1 is described as a first measurement mode. In addition, an operation mode in which the first trigger pulse can be superimposed on the biological signal when the switch element S1 is turned on is described as a second measurement mode. That is, the control unit 60 performs the operation in the first measurement mode and the operation in the second measurement mode. The control unit 60 is realized by, for example, a microcomputer or a processor, but may be realized by a dedicated circuit.

The first trigger pulse is used, for example, to indicate the timing at which a stimulus is presented in measurement of an event-related potential (ERP). FIG. 11 is a diagram for explaining an example of using the first trigger pulse.

The event-related potential is an electrophysiological response to an internal or external stimulus and can be measured by an electroencephalogram. The P300 response is a response that appears in the electroencephalogram around 300 ms after the stimulus is presented. In the example of FIG. 11, as a response of P300, for example, a correct determination is made with respect to an instruction (that is, presentation of a stimulus) via the presentation unit 30 and a response (a) when it is recognized, and the presentation unit The reaction (b) in the case where a correct judgment is made with respect to the instruction through 30 but it is not recognized is shown.

For example, when the letter “L” is displayed on the presentation unit 30, the left button of the mouse is clicked. When the letter “R” is displayed on the presentation unit 30, the right button of the mouse is clicked. It is assumed that the letter “L” is displayed on the presentation unit 30 under the rule. In this case, the reaction (a) when the subject 5 clicks the left button of the mouse and is presented as “correct”. In addition, the reaction (b) is the reaction when the subject 5 is presented as “wrong answer” despite clicking the left button of the mouse.

In such a P300 response measurement, the stimulus presentation timing is displayed together with the electroencephalogram waveform, so that the user can easily identify the portion corresponding to the P300 response in the electroencephalogram waveform.

Therefore, the biological signal measuring device 10b superimposes the first trigger pulse on the biological signal in synchronization with the presentation of the stimulus. Thereby, the presentation part 30 can display the presentation timing of a stimulus with biological signals, such as an electroencephalogram. In the measurement of the P300 response, there is a time difference of 300 ms between the stimulus presentation timing and the corresponding P300 response, so the first trigger pulse has little influence on the P300 response.

[Operation example of biological signal measuring device]
Next, an operation example of the biological signal measuring device 10b will be described in detail. FIG. 12 is a flowchart of an operation example of the biological signal measuring apparatus.

The control unit 60 first performs the operation in the first measurement mode. For example, the control unit 60 outputs the low level control signal CS1 to turn off the switch element S1 (S31).

Next, the control unit 60 determines whether or not a signal for instructing the second measurement mode has been acquired (S32). This determination is performed until a signal indicating the second measurement mode is acquired (NO in S32). The signal instructing the second measurement mode is output from the operation button 41 to the control unit 60 when, for example, the operation button 41 is operated to instruct the second measurement mode. The signal instructing the second measurement mode may be output to the control unit 60 based on an operation on a user interface (not shown) provided in the information processing apparatus 20.

If the control unit 60 determines that the signal instructing the second measurement mode has been acquired (YES in S32), the control unit 60 performs the operation in the second measurement mode. The controller 60 turns on the switch element S1 by outputting a high-level control signal CS1 (S33).

Next, the first pulse generator 56a outputs a first trigger pulse (S34). For example, the first pulse generator 56a acquires a synchronization signal synchronized with the presentation of the above-described stimulus, and outputs a first trigger pulse at a timing determined by the acquired synchronization signal. As a result, the first trigger pulse is superimposed on the biological signal. The first pulse generator 56a may perform such processing based on the control of the control unit 60.

According to the above operation example, the biological signal measuring device 10b can superimpose a pulse on the biological signal.

[Display operation example of biological signal measurement system]
Next, a display operation example of the waveform of the brain wave of the subject 5 in the biological signal measurement system 100 will be described. First, the detailed configuration of the biological signal processing unit 23 of the information processing apparatus 20 will be described in relation to the description of the display operation example. FIG. 13 is a diagram illustrating a detailed configuration of the biological signal processing unit 23. As shown in FIG. 13, the biological signal processing unit 23 includes a biological signal waveform adjustment unit 23 a and a biological signal analysis unit 23 b.

The biological signal waveform adjustment unit 23 a performs waveform adjustment such as adjustment of amplitude on the biological signal acquired by the biological signal acquisition unit 22.

The biological signal analysis unit 23b performs software-like filter processing on the biological signal whose waveform has been adjusted. For example, the biological signal analysis unit 23b functions as a high-pass filter or a low-pass filter. The cutoff frequency of the filter can be changed as appropriate by the user. In addition, the biological signal analysis unit 23b may include a notch filter that blocks only the frequency of hum noise (50 Hz or 60 Hz). The biological signal analysis unit 23 b performs signal processing using these filters and the like, and generates a biopotential waveform displayed by the presentation unit 30 via the display information output unit 27. Alternatively, the biological signal analysis unit 23b may extract a signal having a specific frequency from the biological signal whose waveform has been adjusted, and calculate the power spectral density of the signal at the frequency.

Next, a display operation example of the biological signal measurement system 100 will be described. FIG. 14 is a flowchart of a display operation example of the biological signal measurement system 100. FIG. 15 is a diagram illustrating a display example on the presentation unit 30 in the second measurement mode. FIG. 16 is a diagram illustrating a display example on the presentation unit 30 in the first measurement mode.

First, the application processing unit 26 performs initial processing (S41). As illustrated in FIGS. 15 and 16, the application processing unit 26, in the initial process, includes the measurement electrode 51a and the reference electrode 51b included in the headset 10 worn by the subject 5 on the electrode illustration unit 30c of the presentation unit 30. The position of is displayed.

Next, the application processing unit 26 determines whether or not it is the second measurement mode (S42). When an operation for instructing the second measurement mode is performed on the operation button 41, the application processing unit 26 receives a notification signal transmitted from the headset 10 in response to an operation for instructing the second measurement mode. It is determined whether or not it has been acquired by 21. In addition, when an operation for instructing the second measurement mode is performed on a user interface (not shown) included in the information processing apparatus 20, the application processing unit 26 determines whether such an operation has been performed. To do.

If it is determined that the application processing unit 26 is in the second measurement mode (YES in S42), as shown in FIG. 15, the trigger information is being displayed on the measurement information display unit 30a in the presentation unit 30. (S43). Further, the application processing unit 26 displays “trigger pulse input: present” on the pulse input state display unit 30 e in the presentation unit 30.

On the other hand, when the application processing unit 26 determines that it is not the second measurement mode but the first measurement mode (NO in S42), the measurement information display unit 30a in the presentation unit 30 displays “ “Measurement of biological signal” is displayed (S44). The application processing unit 26 displays “trigger pulse input: none” on the pulse input state display unit 30 e in the presentation unit 30.

Then, a biological signal (here, an electroencephalogram signal) is measured in the biological signal measuring device 10b (S45), and the obtained biological signal is transmitted to the biological signal processing unit 23 via the biological signal acquisition unit 22.

In the biological signal processing unit 23 that has acquired the biological signal, the biological signal waveform adjustment unit 23a adjusts the waveform of the biological signal (S46), and the biological signal analysis unit 23b applies a signal such as filter processing to the biological signal whose waveform has been adjusted. Process. As a result, a biological signal waveform is output from the biological signal analysis unit 23 b to the application processing unit 26.

The application processing unit 26 that has received the biological signal waveform displays the received biological signal waveform on the biological signal waveform display unit 30b in the presentation unit 30 as shown in FIGS. 15 and 16 (S47). As shown in FIG. 15, in the second measurement mode, the application processing unit 26 detects the rising edge of the trigger pulse and displays an arrow indicating the position of the first trigger pulse on the pulse position display unit 30d.

The biological signal waveform displayed on the biological signal waveform display unit 30b is, for example, an average of a plurality of biological signal waveforms corresponding to a plurality of measurements. In this addition averaging, for example, a plurality of biological signal waveforms are added based on the position of the first trigger pulse.

As described above, in the biological signal measurement system 100, the presentation unit 30 is provided with the measurement information display unit 30a indicating the measurement information, the biological signal waveform display unit 30b indicating the biological signal waveform, and the electrode indicating the electrode position in real time. The unit 30c and the pulse input state display unit 30e indicating the input state of the trigger pulse are displayed, and a lot of information can be seen at a glance. Further, in the second measurement mode, the pulse position display unit 30d is displayed on the presentation unit 30, and the position of the trigger pulse can be known at a glance.

[Modification]
In the above embodiment, the measurement electrode 51a for measuring the potential of the biological signal is exemplified as the first electrode, and the first trigger pulse is superimposed on the biological signal detected by the measurement electrode 51a. However, the first electrode may be the reference electrode 51b for measuring the reference potential of the biological signal, and the first trigger pulse may be superimposed on the biological signal detected by the reference electrode 51b.

Further, a trigger pulse may be superimposed on both the biological signal detected by the measurement electrode 51a and the biological signal detected by the reference electrode 51b. FIG. 17 is a circuit block diagram showing a detailed configuration of the biological signal measuring apparatus according to such a modification.

As illustrated in FIG. 17, the biological signal measurement device 10c includes, as components for superimposing the second trigger pulse on the biological signal measurement device 10b, a second pulse generator 56b, a second capacitance element 59b, and a switch element. S2 is added.

The second pulse generator 56b outputs a second trigger pulse. The second trigger pulse is an example of a second pulse. Specifically, the second pulse generator 56b includes a generation circuit 57b and an attenuation circuit 58b.

The generation circuit 57b is an oscillation circuit that generates the original trigger pulse of the second trigger pulse. The generation circuit 57b changes at least one of the amplitude and pulse width of the original trigger pulse based on, for example, an operation performed on the operation button 41. As a result, at least one of the amplitude and pulse width of the second trigger pulse output from the second pulse generator 56b is changed. That is, the second pulse generator 56b can change at least one of the amplitude and the pulse width of the second trigger pulse. Note that at least one of the amplitude and pulse width of the second trigger pulse may be changed based on an operation on a user interface (not shown) included in the information processing apparatus 20.

The attenuation circuit 58b attenuates the original trigger pulse generated by the generation circuit 57b, and outputs a second trigger pulse obtained by attenuation of the original trigger pulse. The circuit configuration of the attenuation circuit 58b is the same as that of the attenuation circuit 58a.

Note that the second pulse generator 56b may be an interface circuit or a terminal that acquires a second trigger pulse from a signal generation device provided outside the biological signal measurement device 10c. That is, it is not essential that the second pulse generator 56b includes the generation circuit 57b and the attenuation circuit 58b.

Further, when the second trigger pulse has the same polarity as the first trigger pulse, the first trigger pulse and the second trigger pulse may be canceled in the differential amplifier circuit 74. Therefore, the second trigger pulse may have a polarity opposite to that of the first trigger pulse.

The second capacitive element 59b capacitively couples the output terminal of the second pulse generator 56b and the input terminal of the second amplifier circuit 52b. The second capacitive element 59b is an element for superimposing the second trigger pulse on the biological signal. The capacitance value of the second capacitive element 59b is, for example, 100 pF.

The switch element S2 is connected between the input terminals of the second capacitor element 59b and the second amplifier circuit 52b. The switch element S2 switches the presence / absence of electrical connection between the input terminals of the second capacitor element 59b and the second amplifier circuit 52b according to the control signal CS2 output from the control unit 60. The switch element S2 is, for example, an FET, but may be another switch element. Although the switch element S2 may be omitted, if the switch element S2 is turned off when the second trigger pulse is not superimposed on the biological signal, the influence on the biological signal of the second pulse generator 56b is reduced. be able to.

The control unit 60 switches the switching element S1 on and off by outputting the control signal CS1, and switches the switching element S2 on and off by outputting the control signal CS2. For example, in the first measurement mode, the switch element S1 and the switch element S2 are turned off, and in the second measurement mode, the switch element S1 and the switch element S2 are turned on.

[Active electrode]
18A and 18B, the measurement electrode 51a and the first amplifier circuit 52a may be realized as the active electrode 50 by being mounted on one substrate 55, for example. 18A and 18B are schematic views showing the appearance of the active electrode 50. FIG. As shown in FIG. 18A, the measurement electrode 51a is mounted on one main surface 55a of the substrate 55, and as shown in FIG. 18B, the first amplifier circuit 52a is mounted on the other main surface 55b of the substrate 55. Is done. Thus, if the measurement electrode 51a and the first amplifier circuit 52a are mounted on one substrate 55, the wiring length of the wiring that electrically connects the measurement electrode 51a and the first amplifier circuit 52a can be shortened. Then, generation | occurrence | production of unnecessary noise etc. are suppressed.

It should be noted that the first capacitor element 59a and the switch element S1 may be further mounted on the substrate 55. Although not shown, the reference electrode 51b and the second amplifier circuit 52b may also be realized as active electrodes by being mounted on one substrate.

[Effects]
As described above, the biological signal measuring apparatus 10b includes the first pulse generator 56a that outputs the first trigger pulse and the first amplifier circuit 52a that receives the biological signal detected by the first electrode that contacts the living body. And a first capacitive element 59a for capacitively coupling the output terminal of the first pulse generator 56a and the input terminal of the first amplifier circuit 52a for superimposing the first trigger pulse on the biological signal. The first trigger pulse is an example of the first pulse.

Such a biological signal measuring apparatus 10b can superimpose the first trigger pulse on the biological signal.

For example, the first pulse generator 56a includes an attenuation circuit 58a, and the first trigger pulse is a signal obtained by attenuating the original pulse by the attenuation circuit 58a.

Such a biological signal measuring apparatus 10b can generate a first trigger pulse having a relatively small amplitude suitable for a biological signal by attenuating a trigger pulse having a relatively large amplitude.

Also, for example, the attenuation circuit 58a can change the attenuation amount of the original pulse.

Such a biological signal measuring apparatus 10b can generate a first trigger pulse having an arbitrary amplitude suitable for a biological signal by attenuating a trigger pulse having a relatively large amplitude.

For example, the first pulse generator 56a can change at least one of the amplitude and the pulse width of the first trigger pulse.

Such a biological signal measuring apparatus 10b can change at least one of the amplitude and the pulse width of the first trigger pulse.

Further, for example, the biological signal measuring device 10b further includes a switch element S1 that switches presence / absence of electrical connection between the input terminals of the first capacitor element 59a and the first amplifier circuit 52a.

In such a biological signal measuring apparatus 10b, if the switch element S1 is turned off when the first trigger pulse is not superimposed on the biological signal, the influence of the first pulse generator 56a on the biological signal can be reduced.

Further, for example, the biological signal measuring device 10b can superimpose the first trigger pulse on the biological signal by further operating in the first measurement mode in which the switch element S1 is turned off and turning on the switch element S1. The control part 60 which performs operation | movement of a 2nd measurement mode is provided.

Such a biological signal measurement device 10b can switch between the first measurement mode and the second measurement mode.

Also, for example, the first electrode is a measurement electrode 51a for measuring the potential of a biological signal.

Such a biological signal measuring device 10b can superimpose the first trigger pulse on the biological signal detected by the measurement electrode 51a. That is, the first trigger pulse can selectively appear only in the biological signal waveform of the biological signal detected by the specific measurement electrode 51a among the plurality of electrodes 51.

For example, the first electrode is a reference electrode 51b for measuring a reference potential of a biological signal.

Such a biological signal measuring device 10b can superimpose the first trigger pulse on the biological signal detected by the reference electrode 51b. If the first trigger pulse is superimposed on the biological signal detected by the reference electrode 51b, the first trigger pulse appears in common with the biological signal waveform of the biological signal detected by the plurality of electrodes 51 other than the reference electrode 51b. be able to.

Further, for example, the biological signal measuring device 10c further includes a second pulse generator 56b that outputs a second trigger pulse and a second amplifier circuit 52b that receives a biological signal detected by a second electrode that contacts the living body. And a second capacitive element 59b that capacitively couples the output terminal of the second pulse generator 56b and the input terminal of the second amplifier circuit 52b. The second electrode is a reference electrode 51b for measuring the reference potential of the biological signal. The second trigger pulse is an example of a second pulse.

Such a biological signal measuring device 10b can superimpose the second trigger pulse on the biological signal detected by the reference electrode 51b.

Also, for example, the second trigger pulse has a polarity opposite to that of the first trigger pulse.

This suppresses the first trigger pulse and the second trigger pulse from being canceled in the differential amplifier circuit 74.

The biological signal measuring device 10b further includes a first electrode and a substrate 55 on which the first electrode and the first amplifier circuit 52a are mounted.

Such a biological signal measuring apparatus 10b can suppress the generation of unnecessary noise by shortening the wiring length of the wiring that electrically connects the first electrode and the first amplifier circuit 52a.

Also, an electroencephalograph such as the headset 10 includes a biological signal measuring device 10b (or a biological signal measuring device 10c) and a mounting portion 40 provided on the head of the living body and provided with a first electrode.

Such an electroencephalograph can superimpose a first trigger pulse on a biological signal.

Moreover, the control method of the biological signal measuring device 10b (or the biological signal measuring device 10c) includes the operation of the first measurement mode in which the switch element S1 is turned off, and the first trigger pulse is turned on by turning on the switch element S1. The operation in the second measurement mode that can be superimposed on the signal is performed.

Such a control method can switch between the first measurement mode and the second measurement mode.

(Other embodiments)
Although the embodiment has been described above, the present invention is not limited to such an embodiment.

For example, in the above embodiment, the pulse is superimposed at the timing of presentation of the stimulus to the subject, but the pulse may be superimposed a plurality of times in the measurement of the biological signal. For example, pulses may be superimposed at each timing of measurement start timing, stimulus presentation timing, and measurement end timing. In this case, if the pulse shape is different for each timing, the application processing unit can identify the measurement start timing, the stimulus presentation timing, and the measurement end timing by detecting the pulse.

In the above embodiment, the biological signal measuring device is mainly used for measuring the event-related potential, but the use of the biological signal measuring device is not limited to such a use.

Further, the circuit configuration described in the above embodiment is an example, and the present invention is not limited to the above circuit configuration. That is, like the above circuit configuration, a circuit that can realize a characteristic function of the present invention is also included in the present invention. For example, a device in which an element such as a switch element (transistor), a resistor element, or a capacitor element is connected in series or in parallel to a certain element within a range in which the same function as the above circuit configuration can be realized is also included in the present invention. included.

In the above embodiment, another processing unit may execute a process executed by a specific processing unit. Further, the order of the plurality of processes may be changed, and the plurality of processes may be executed in parallel.

In the above embodiment, the components such as the control unit may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or a processor reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory.

Further, the components such as the control unit may be realized by hardware. For example, the component such as the control unit may be a circuit (or an integrated circuit). These circuits may constitute one circuit as a whole, or may be separate circuits. Each of these circuits may be a general-purpose circuit or a dedicated circuit.

The general or specific aspect of the present invention may be realized by a recording medium such as a system, an apparatus, a method, an integrated circuit, a computer program, or a computer-readable CD-ROM. Further, the present invention may be realized by any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

For example, the present invention may be realized as a control method of a biological signal measurement device, or may be realized as a program for causing a computer to execute such a control method. Further, the present invention may be realized as a computer-readable non-transitory recording medium in which such a program is recorded.

Further, the biological signal measurement system described in the above embodiment may be realized as a single device or may be realized by a plurality of devices. When the biological signal measurement system is realized by a plurality of devices, the components included in the biological signal measurement system described in the above embodiment may be distributed to the plurality of devices in any way.

In addition, one or a plurality of modes may be used in the present embodiment in which various modifications conceived by those skilled in the art have been made in this embodiment, or in a configuration constructed by combining components in different embodiments, without departing from the spirit of the present invention. It may be included in the range.

10 Headset (electroencephalograph)
10b, 10c Biological signal measuring device 40 Wearing part 51a Measuring electrode (first electrode)
51b Reference electrode (first electrode, second electrode)
52a first amplifier circuit 52b second amplifier circuit 55 substrate 56a first pulse generator 56b second pulse generator 58a, 58b attenuation circuit 59a first capacitor element 59b second capacitor element 60 control unit 74 differential amplifier circuit S1, S2 Switch element

Claims (14)

1. A first pulse generator for outputting a first pulse;
   A first amplifier circuit to which a biological signal detected by the first electrode that contacts the living body is input;
   A biological signal measurement device comprising: a first capacitive element for capacitively coupling an output terminal of the first pulse generator and an input terminal of the first amplifier circuit for superimposing the first pulse on the biological signal.
2. The first pulse generator includes an attenuation circuit;
   The biological signal measurement device according to claim 1, wherein the first pulse is a signal obtained by attenuating the original pulse by the attenuation circuit.
3. The biological signal measurement device according to claim 2, wherein the attenuation circuit is capable of changing an attenuation amount of the original pulse.
4. The biological signal measuring apparatus according to any one of claims 1 to 3, wherein the first pulse generator is capable of changing at least one of an amplitude and a pulse width of the first pulse.
5. The biological signal measuring device according to any one of claims 1 to 4, further comprising a switch element for switching presence / absence of electrical connection between the first capacitor element and an input terminal of the first amplifier circuit.
6. Further, the control for performing the operation in the first measurement mode in which the switch element is turned off, and the operation in the second measurement mode in which the first pulse can be superimposed on the biological signal by turning on the switch element. The biological signal measuring device according to claim 5.
7. The biological signal measuring device according to any one of claims 1 to 6, wherein the first electrode is a measurement electrode for measuring a potential of the biological signal.
8. The biological signal measuring device according to any one of claims 1 to 6, wherein the first electrode is a reference electrode for measuring a reference potential of the biological signal.
9. further,
   A second pulse generator for outputting a second pulse;
   A second amplification circuit to which a biological signal detected by the second electrode in contact with the living body is input;
   A second capacitive element that capacitively couples the output terminal of the second pulse generator and the input terminal of the second amplifier circuit;
   The biological signal measuring device according to claim 7, wherein the second electrode is a reference electrode for measuring a reference potential of the biological signal.
10. The biological signal measurement device according to claim 9, wherein the second pulse has a polarity opposite to that of the first pulse.
11. further,
    The first electrode;
    The biological signal measuring device according to any one of claims 1 to 10, further comprising a substrate on which the first electrode and the first amplifier circuit are mounted.
12. The biological signal measuring device according to any one of claims 1 to 11,
    An electroencephalograph comprising: a mounting portion mounted on the head of the living body and provided with the first electrode.
13. A control method of a biological signal measuring device,
    The biological signal measuring device is
    A first pulse generator for outputting a first pulse;
    A first amplifier circuit to which a biological signal detected by the first electrode that contacts the living body is input;
    A capacitive element for capacitively coupling the output terminal of the first pulse generator and the input terminal of the first amplifier circuit for superimposing the first pulse on the biological signal;
    A switching element connected between the capacitive element and the input terminal of the first amplifier circuit;
    The control method is:
    A control method for performing an operation in a first measurement mode in which the switch element is turned off, and an operation in a second measurement mode in which the first pulse can be superimposed on the biological signal by turning on the switch element.
14. A program for causing a computer to execute the control method according to claim 13.

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