Active acquisition electrode, charging device, electroencephalogram acquisition system and application method

Abstract

The invention relates to the technical field of brain-computer interfaces, and discloses an active acquisition electrode, a charging device, an electroencephalogram acquisition system and an application method. The active acquisition electrode comprises a rechargeable power supply assembly, an active circuit board, an electrode base, a Laplace electrode inner ring, a Laplace electrode outer ring and an insulating patch; the rechargeable power supply assembly supplies power to the active circuit board; the electrode base is located on the rechargeable power supply assembly; the electrode base is provided with an annular containing space, the Laplacian electrode inner ring and the Laplacian electrode outer ring are contained in an inner ring space and an outer ring space of the annular containing space respectively and are wrapped by insulating patches, and an amplification module, a high-pass filtering module, a low-pass filtering module and a voltage stabilizing module are arranged on the active circuit board. The common reference connection with various general amplifiers can be realized, the application range is wide, the electrode can directly perform preliminary amplification and filtering processing on signals at a signal source, and the signal-to-noise ratio and the overall stability of the acquired signals can be improved.

Description

Technical Field

[0001] The present invention relates to the field of brain-computer interface technology, and in particular to an active collection electrode, a charging device, an electroencephalogram collection system and an application method. Background Art

[0002] Brain-Computer Interface (BCI) is a system that directly converts central nervous system (CNS) activities into artificial outputs, aiming to improve the interaction between the central nervous system and the external environment. A typical BCI system usually consists of four main parts: signal acquisition, signal analysis, peripheral control, and neural feedback. Among them, signal acquisition is the primary link of the system. Its acquisition accuracy and signal quality directly determine the effect of subsequent signal processing, so it plays a vital role in the BCI system.

[0003] In the process of signal acquisition, electroencephalogram (EEG) is widely used in BCI systems due to its non-invasive, real-time and high temporal resolution characteristics. EEG is a method of recording electrophysiological signals generated by placing electrodes on the surface of the scalp to record the activity of cortical neurons. Its main advantage is that it can capture the potential fluctuations of brain regions with a temporal resolution of milliseconds, thereby accurately reflecting the instantaneous dynamic characteristics of different functional areas of the brain. However, in the process of transmitting from the cortex to the surface of the scalp, EEG signals will be affected by various media such as the scalp, skull, cerebrospinal fluid and blood. The conductive properties of these biological media will form a volume conductor effect to varying degrees. When EEG signals are diffused and mixed through different media, the position and intensity of the signal source are distorted, making the collected EEG signals not only have a low spatial resolution, but also difficult to accurately locate the source of neural activity. This effect is particularly significant on conventional disc electrodes, causing the spatial characteristics of the signal to be blurred, thereby reducing the accuracy of signal analysis and classification in the BCI system, and limiting its application in complex cognitive tasks and high-precision control.

[0004] The prior art proposes an active electrode, which adds a preamplifier circuit on the basis of the traditional disk electrode to perform preliminary amplification at the signal acquisition source to reduce interference, but this active electrode has the following defects:

[0005] 1) The preamplifier circuit needs to use a standard operational amplifier module and requires a power supply, filtering and protection circuit, which makes the overall package volume of the electrode larger and increases the difficulty of electrode layout;

[0006] 2) Due to the addition of the preamplifier circuit, this type of electrode needs to be laid out separately for power lines and signal transmission lines, resulting in a complex wiring structure. In a system with a high number of channels, a large number of power lines and signal lines are intertwined, which can easily cause wiring confusion, signal crosstalk, and other problems, affecting the overall convenience and stability of use;

[0007] 3) The active electrode needs to be independently equipped with a reference electrode during signal acquisition, which can easily introduce common reference contamination and lead to poor signal acquisition quality;

[0008] 4) The active electrode cannot be connected to a variety of different types of amplifiers, which limits its application scenarios;

[0009] 5) The active electrode is powered by AC power or a standard DC power supply. This power supply method is easily affected by power frequency interference and power supply fluctuations. Once the voltage fluctuates or the power supply is poorly grounded, the stability of the output signal of the amplifier circuit will be seriously affected, resulting in obvious power frequency noise or baseline drift in the collected signal, thereby reducing the quality and availability of the EEG signal. Summary of the invention

[0010] The purpose of the present invention is to provide an active collection electrode, a charging device, an EEG collection system and an application method, which can overcome the problems of existing active electrodes, such as difficulty in layout, poor convenience and stability in use, easy introduction of common reference pollution, and great influence of voltage fluctuations.

[0011] In order to achieve the above object, the present invention adopts the following technical scheme:

[0012] In a first aspect, the present invention provides an active collection electrode, comprising: a rechargeable power supply component, an active circuit board, an electrode base, a Laplace electrode inner ring, a Laplace electrode outer ring and an insulating patch;

[0013] The rechargeable power supply component supplies power to the active circuit board; the electrode base is located on the rechargeable power supply component; the electrode base has an annular accommodation space at one end away from the rechargeable power supply component; the inner ring of the Laplace electrode is accommodated in the inner ring space of the annular accommodation space, and the outer ring of the Laplace electrode is accommodated in the outer ring space of the annular accommodation space; the inner ring of the Laplace electrode and the outer ring of the Laplace electrode are directly connected to the active circuit board; the active circuit board is equipped with an amplification module, a high-pass filtering module and a low-pass filtering module to amplify and filter the differential signals of the inner ring of the Laplace electrode and the outer ring of the Laplace electrode in turn; the active circuit board is also equipped with a voltage stabilization module to stabilize the voltage provided by the rechargeable power supply component;

[0014] The insulating patch is attached to the electrode base and isolates the inner ring of the Laplace electrode from the outer ring of the Laplace electrode.

[0015] As a possible implementation, the inner ring of the Laplace electrode and the outer ring of the Laplace electrode are made of a material with an electrode bias voltage less than or equal to 5 mV and an average drift rate less than or equal to 18±7 mV / min in a stable state.

[0016] As a possible implementation, the Laplace electrode inner ring and the Laplace electrode outer ring are made of silver-silver chloride material, disposable Ag / AgCl, silver, gold, platinum, stainless steel or tin.

[0017] As a possible implementation manner, the area of ​​the inner ring of the Laplace electrode is S1, the area of ​​the outer ring of the Laplace electrode is S2, and S2 / S1=1.5-11.4.

[0018] As a possible implementation, the radius of the inner ring of the Laplace electrode is Rs, Rs≤4mm; the inner diameter of the outer ring of the Laplace electrode is Ri, Rs<Ri≤8mm; and the outer diameter of the outer ring of the Laplace electrode is Ro, Ri<Ro≤12mm.

[0019] As a possible implementation, the rechargeable power supply assembly includes a protective shell, a rechargeable battery and a contact seat; wherein the rechargeable battery and the active circuit board are both detachably stacked up and down and are fastened to the protective shell; one end of the contact seat is fastened to the active circuit board to connect to the positive and negative power interfaces of the rechargeable battery, and the other end of the contact seat is connected to the charging contact of the charging device to connect to the charging circuit board in the charging device;

[0020] and / or,

[0021] An extension interface is provided longitudinally through the extension of the electrode base.

[0022] In a second aspect, the present invention provides a charging device, which charges one or more active collection electrodes provided in the first aspect;

[0023] The charging device includes a charging base, a charging circuit board and a charging cover plate stacked from bottom to top; wherein the charging circuit board is provided with a power supply interface, a plurality of groups of retractable charging contacts, and a switch is provided for each group of charging contacts; the power supply interface can charge the charging contacts through the switch;

[0024] The charging cover is provided with multiple charging areas, each of which corresponds to a set of charging contacts, that is, each set of charging contacts penetrates the cover where the charging area is located and can be controllably extended and retracted;

[0025] When charging, the contact holder magnetically attracts the charging contacts to achieve connection.

[0026] In a third aspect, the present invention provides an electroencephalogram (EEG) acquisition system, comprising:

[0027] A display for presenting the stimulus paradigm interface;

[0028] The active collection electrode is the active collection electrode provided in the first aspect, and is attached to the subject's head through an insulating patch; the inner ring radius Rs of the Laplace electrode is 3 mm, the inner ring diameter Ri of the Laplace electrode is 7 mm, and the outer ring diameter Ro of the Laplace electrode is 10 mm; the amplification factor of the amplification module on the active circuit board is k times, 1<k<45; the parameters of the bandpass filter module are within the range of 0.01 Hz to 100 Hz;

[0029] The amplifier is electrically connected to the active collection electrode in a common reference connection manner, that is, the inner ring of the Laplace electrode is connected to the reference end of the amplifier; it receives the analog signal of the active collection electrode and obtains the EEG data after performing digital-to-analog conversion on the analog signal;

[0030] The host computer receives the EEG data, processes the data and displays it.

[0031] In a fourth aspect, the present invention provides an electroencephalogram (EEG) acquisition system, comprising:

[0032] A display for presenting the stimulus paradigm interface;

[0033] An EEG acquisition headband, wherein a plurality of mounting holes for active acquisition electrodes are preset on the EEG acquisition headband, and an active acquisition electrode is embedded in each mounting hole; the active acquisition electrode is the active acquisition electrode provided in the first aspect; the inner ring radius Rs of the Laplace electrode is 2 mm, the inner ring diameter Ri of the Laplace electrode is 6 mm, and the outer ring diameter Ro of the Laplace electrode is 9 mm; the amplification factor of the amplification module on the active circuit board is k times, 1<k<45; the parameters of the bandpass filter module are within the range of 0.01 Hz to 100 Hz;

[0034] The amplifier is electrically connected to the active collection electrode in a common reference connection manner, that is, the inner ring of the Laplace electrode is connected to the reference end of the amplifier; it receives the analog signal of the active collection electrode and obtains the EEG data after performing digital-to-analog conversion on the analog signal;

[0035] The host computer receives the EEG data, processes the data and displays it.

[0036] In a fifth aspect, the present invention provides another EEG acquisition system, comprising:

[0037] A display for presenting the stimulus paradigm interface;

[0038] An electrode cap, wherein the electrode cap is composed of a plurality of active collection electrodes connected via an expansion interface; the active collection electrode is the active collection electrode provided in the first aspect, and is pasted on the subject's head via an insulating patch; the inner ring radius Rs of the Laplace electrode is 1 mm, the inner ring diameter Ri of the Laplace electrode is 4 mm, and the outer ring diameter Ro of the Laplace electrode is 5 mm; the amplification factor of the amplification module on the active circuit board is k times, 1<k<45; the parameters of the bandpass filter module are within the range of 0.01 Hz to 100 Hz;

[0039] The amplifier is electrically connected to the active collection electrode in a common reference connection manner, that is, the inner ring of the Laplace electrode and the reference end of the amplifier are connected to receive the analog signal of the active collection electrode, and the analog signal is converted into digital-to-analog form to obtain the EEG data;

[0040] The host computer receives the EEG data, processes the data and displays it.

[0041] In a sixth aspect, the present invention provides an application method of an EEG acquisition system, and after configuring the EEG acquisition system provided by any one of the third aspect to the fifth aspect, the following steps are performed:

[0042] An active collection electrode is worn on the subject's head, and the Laplace electrode inner ring and the Laplace electrode outer ring are combined to form a signal collection unit to obtain the subject's original EEG signal; the original EEG signal is a differential signal between the EEG signal collected by the Laplace electrode outer ring and the reference signal of the Laplace electrode inner ring; the differential signal is pre-amplified and filtered before being transmitted to the amplifier;

[0043] Active collection electrodes are worn on the front or back of the subject's head, and the subject performs EEG induction according to the prompts on the display;

[0044] The amplifier amplifies the differential signal output by the active acquisition electrode and obtains EEG data after analog-to-digital conversion;

[0045] The host computer receives computer data, processes and displays the EEG data.

[0046] Compared with the prior art, the beneficial effects of the present invention are:

[0047] 1. The active collection electrode provided by the present invention fully considers the compatibility with existing general amplifiers, and realizes connection with various types of general amplifiers in a common reference manner. That is, the inner ring of the Laplace electrode is connected to the reference end of the amplifier, so that the amplifier can receive the analog signal of the active collection electrode and perform digital-to-analog conversion on the analog signal to obtain EEG data, which greatly expands the application scope of the active reference electrode.

[0048] 2. Different from the traditional disk electrode, the active collection electrode provided by the present invention is a bipolar concentric ring structure, with the inner ring of the Laplace electrode as the benchmark reference electrode, and the outer ring of the Laplace electrode is used to collect EEG signals, and then the EEG signals collected by the outer ring are differentially processed with the benchmark reference signals of the inner ring, thereby avoiding the common reference contamination problem introduced by independent reference electrodes, which can significantly improve the signal quality in the multi-channel collection process, enhance the reliability of EEG signal collection, and help to improve the spatial resolution of EEG signals.

[0049] 3. The active collection electrode proposed in the present invention, the inner ring and the outer ring of the electrode are made of silver-silver chloride material, disposable Ag / AgCl, silver, gold, platinum, stainless steel or tin and other materials with high conductivity and good biocompatibility, which can significantly improve the service life and signal quality of the electrode.

[0050] 4. The present invention optimizes the radius and area ratio of the inner ring and the outer ring of the Laplace electrode, and uses the original signal collected by the optimized electrode for differential processing to obtain a differential mode signal. In this way, the common mode signal interference to the differential mode signal is low, and the radius and area ratio of the inner ring and the outer ring of the Laplace electrode provided by the present invention are simpler and easier to implement for the manufacturing process of the active collection electrode, and can be applied to mass industrial production.

[0051] 5. The active collection electrode provided by the present invention is equipped with an amplification module, a high-pass filter module and a low-pass filter module on its active circuit board, so that the electrode itself can directly perform preliminary amplification and filtering processing on the signal at the signal source, which can significantly reduce the impact of traditional long-wire transmission on signal quality, and can effectively suppress the power frequency interference and motion artifact interference introduced by the large loop, improve the signal-to-noise ratio and overall stability of the collected signal, and effectively ensure the high-fidelity collection and transmission of weak EEG signals.

[0052] 6. The active collection electrode provided by the present invention can be pasted to the subject's head through an insulating patch, which can not only make the electrode in close contact with the subject's scalp, but also improve the subject's comfort and can be flexibly arranged on the subject's head. The electrode fixing method of the present invention is simple, easy to install and disassemble, and an expansion interface is reserved on the electrode base, which supports flexible adjustment of the number and position of electrodes according to different needs, can improve the flexibility of electrode arrangement during multi-channel EEG signal collection, and can provide a more convenient multi-channel signal collection solution for complex experimental scenarios.

[0053] 7. The charging device provided by the present invention can charge multiple active collection electrodes at the same time, which can solve the problem of frequent battery replacement of traditional electrodes. The charging device adopts a magnetic charging design. Users only need to place the electrodes in the charging area to complete the charging operation. It is convenient and efficient, and extends the working time of the active collection electrodes. It can improve the continuity and stability of the electrodes during long-term work, and significantly improve the overall work efficiency.

[0054] 8. The active collection electrodes provided by the present invention can be applied to a variety of EEG collection systems. The number of electrodes and the electrode placement positions can be flexibly selected according to actual needs to achieve different purposes, and have a wide range of application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0056] Figure 1 A schematic diagram of the structure of an active collection electrode provided in an embodiment of the present invention;

[0057] Figure 2 A comparison diagram of a conventional disk electrode arrangement in an embodiment of the present invention and a two-ring Laplace electrode arrangement in the present invention;

[0058] Figure 3 This is a schematic diagram of a signal processing path formed by two rings of Laplace electrodes, an active circuit board and a charging component in an embodiment of the present invention;

[0059] Figure 4 Schematic diagram of active circuit of active collection electrode in an embodiment of the present invention;

[0060] Figure 5 A schematic diagram of the shapes that can be selected for the active circuit board in the embodiment of the present invention;

[0061] Figure 6 The schematic diagram of the positional relationship between the two rings of Laplace electrodes and the insulating patch in the embodiment of the present invention;

[0062] Figure 7 A schematic diagram of an extension interface provided on the extension of the electrode base in an embodiment of the present invention;

[0063] Figure 8 Schematic diagram comparing the radii of the inner ring of the Laplace electrode and the outer ring of the Laplace electrode in an embodiment of the present invention;

[0064] Fig. 9 This is a schematic diagram of the inner and outer rings of the Laplace electrode being equivalent to input resistance in an embodiment of the present invention;

[0065] Fig.10 A schematic diagram of the active collection electrode and the general amplifier being connected in a common reference manner in an embodiment of the present invention;

[0066] Fig.11 It is a schematic diagram of comparative experimental results of measuring system self-noise when the input terminal is short-circuited in an embodiment of the present invention;

[0067] Fig.12 This is a schematic diagram of the experimental results of placing a standard sinusoidal signal source at the input end and performing a signal waveform display comparison in an embodiment of the present invention;

[0068] Fig.13 This is a schematic diagram of the structure of a charging device in an embodiment of the present invention;

[0069] Fig.14 This is a schematic diagram of a power supply interface charging a charging contact through switch control in an embodiment of the present invention;

[0070] Fig.15 This is a schematic diagram of inserting an active collection electrode into a charging device in an embodiment of the present invention;

[0071] Fig.16 A cross-sectional view of inserting an active collection electrode into a charging device in an embodiment of the present invention;

[0072] Fig.17 It is a top view of the active collection electrode after being placed on the charging device in the embodiment of the present invention;

[0073] Fig.18 A schematic diagram of a charging circuit of a charging device according to an embodiment of the present invention;

[0074] Fig.19 A schematic diagram of an electroencephalogram acquisition system provided in the third aspect of an embodiment of the present invention;

[0075] Fig. 20 A schematic diagram of an EEG acquisition system provided in the fourth aspect of an embodiment of the present invention;

[0076] Fig.21 This is a schematic diagram of the structure of the EEG acquisition headband in an embodiment of the present invention;

[0077] Fig. 22 A schematic diagram of an electroencephalogram acquisition system provided in the fifth aspect of an embodiment of the present invention;

[0078] Fig.23 Schematic diagram of the electrode cap structure in an embodiment of the present invention.

[0079] Reference numerals

[0080] 1-active collection electrode, 10-rechargeable power supply component, 100-protective shell, 101-rechargeable battery, 102-contact seat, 11-active circuit board, 12-electrode base, 120-expansion interface, 13-Laplace electrode inner ring, 14-Laplace electrode outer ring, 15-insulating patch, 16-detachable bolt;

[0081] 2-charging device, 20-charging base, 21-charging circuit board, 210-power supply interface, 211-charging contact, 212-switch, 22-charging cover, 220-charging area;

[0082] 3-display, 4-amplifier, 5-host computer, 6-EEG acquisition headband, 7-electrode cap. DETAILED DESCRIPTION

[0083] In order to clearly describe the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, words such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and effects. For example, the first threshold and the second threshold are only used to distinguish different thresholds, and their order is not limited. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different.

[0084] It should be noted that, in the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0085] In the present invention, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. The following at least one item (items) or similar expressions thereof refer to any combination of these items, including any combination of single items (items) or plural items (items). For example, at least one item (items) of a, b or c can mean: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b and c, where a, b, c can be single or multiple.

[0086] The present invention aims to propose an active collection electrode, a charging device, an EEG collection system and an application method, which can solve the problems of existing active electrodes, such as difficulty in layout, poor convenience and stability in use, easy introduction of common reference pollution, and great influence of voltage fluctuations.

[0087] In a first aspect, an embodiment of the present invention provides an active collection electrode, see Figure 1 The active collection electrode 1 comprises: a rechargeable power supply component 10, an active circuit board 11, an electrode base 12, a Laplace electrode inner ring 13, a Laplace electrode outer ring 14 and an insulating patch 15; the rechargeable power supply component 10 supplies power to the active circuit board 11; the electrode base 12 is located on the rechargeable power supply component 10; the electrode base 12 has an annular accommodation space at one end away from the rechargeable power supply component 10; the Laplace electrode inner ring 13 is accommodated in the inner ring space of the annular accommodation space, and the Laplace electrode outer ring 14 is accommodated in the outer ring space of the annular accommodation space; the Laplace electrode inner ring 13 and the Laplace electrode outer ring 14 are directly connected to the active circuit board 11;

[0088] See also Figure 2 Compared with the traditional arrangement of disk electrodes, the present invention adopts a two-ring Laplace electrode. The inner ring of the Laplace electrode is used as a reference electrode, and the outer ring of the Laplace electrode is used to collect EEG signals. The EEG signals collected by the outer ring are then differentially processed with the reference signals of the inner ring, thereby avoiding the common reference pollution problem introduced by independent reference electrodes, significantly improving the signal quality in the multi-channel acquisition process, improving the reliability of EEG signal acquisition, and helping to improve the spatial resolution of EEG signals.

[0089] See also Figure 1 , Figure 3 and Figure 4 The Laplace electrode inner ring 13 and the Laplace electrode outer ring 14 are directly connected to the active circuit board 11, and the active circuit board 11 is equipped with an amplification module, a high-pass filter module and a low-pass filter module to amplify and filter the differential signals of the Laplace electrode inner ring 13 and the Laplace electrode outer ring 14 in sequence. The active circuit of the active circuit board 11 takes the differential signal of the Laplace electrode inner ring 13 and the Laplace electrode outer ring 14 as input, see Figure 4, the positive input end of the active circuit is connected to the outer ring 14 of the Laplace electrode, and the negative input end is connected to the inner ring 13 of the Laplace electrode. A capacitor is provided on the transmission path of the collected signal from the outer ring 14 of the Laplace electrode to the amplification module. The capacitor filters the collected signal before amplification. Then, the appropriate amplification factor is selected by the amplification module configured on the active circuit board 11, and the differential signal is pre-amplified. Then, the high-pass filter module and the low-pass filter module are used to weaken the influence of low-frequency interference, baseline drift and high-frequency noise, so as to ensure high-quality transmission of the signal within the effective frequency band and improve the stability and accuracy of signal acquisition. In addition, a voltage stabilization module is also configured on the active circuit board 11 to convert the voltage provided by the rechargeable power supply component 10 into the required stable voltage. With such a design, the electrode itself can directly perform preliminary amplification and filtering processing on the signal at the signal source, which can significantly reduce the influence of long wire transmission on signal quality, and can effectively suppress the power frequency interference and motion artifact interference introduced by the large loop, improve the signal-to-noise ratio and overall stability of the collected signal, and effectively ensure the high-fidelity collection and transmission of weak EEG signals.

[0090] See also Figure 5 As an example, the active circuit board 11 is used as a base component, and its shape can be any shape such as square, round, polygonal, etc. The present invention does not make a specific limitation, and its size range is not fixed. Different packages such as 0201, 0402, 0603 can be selected according to the resistor and capacitor package. The use of a small package can effectively reduce the size of the base component, realize the miniaturization design of the electrode, and meet different usage requirements.

[0091] See also Figure 1 As a possible implementation, the rechargeable power supply component 10 includes a protective shell 100, a rechargeable battery 101 and a contact seat 102; wherein the rechargeable battery 101 and the active circuit board 11 are both stacked up and down in a detachable manner and are fastened to the protective shell 100; the protective shell 100 is used to fix the active circuit board 11 and provide a limit and support for the contact seat 102. The rechargeable battery 101 (for example, a lithium battery) is used to provide a low-noise linear stable voltage to the active circuit board 11 to reduce the interference of electrical noise. One end of the contact seat 102 is fastened to the active circuit board 11 to connect the positive and negative power supply interfaces, and the other end of the contact seat 102 is connected to the charging contact of the charging device to connect the charging circuit board in the charging device; and / or, an extension interface 120 is provided on the extension of the electrode base 12 longitudinally. The active collection electrode provided in this embodiment is powered by an independent rechargeable battery 101 in the rechargeable power supply component 10, without the need for a power cable, which can eliminate the interference problem caused by the power cable and improve flexibility.

[0092] See also Figure 1 and Figure 6The electrode base 12 is provided with an annular accommodation space for accommodating the inner ring 13 and the outer ring 14 of the Laplace electrode. The insulating patch 15 is fitted with the electrode base 12 and isolates the inner ring 13 and the outer ring 14 of the Laplace electrode. In practical application, the insulating patch 15 can be made of double-sided adhesive cotton. The electrode is attached to the subject's head through the insulating patch 15, which can not only make the electrode in close contact with the subject's scalp, but also improve the subject's comfort and can be flexibly arranged on the subject's head.

[0093] See also Figure 1 and Figure 7 An expansion interface 120 is provided around the extension of the electrode base 12. As an example, four expansion interfaces 120 are provided, which support flexible adjustment of the number and position of electrodes according to different needs and can meet diverse EEG signal acquisition needs.

[0094] The electrode fixing method of the present invention is simple and easy to install and disassemble. At the same time, the expansion interface reserved in the present invention can improve the flexibility of electrode arrangement during multi-channel EEG signal acquisition. The multi-channel scalability can be improved by connecting elastic bands to form an EEG cap, so as to provide a more convenient multi-channel signal acquisition solution for complex experimental scenarios and meet the needs of multi-channel EEG research and new applications.

[0095] See also Figure 1 As an example, the electrode base 12 and the protective shell 100 are connected by a detachable bolt 16, which fastens the electrode structure and facilitates quick disassembly.

[0096] As a possible implementation method, the Laplace electrode inner ring 13 and the Laplace electrode outer ring 14 are made of materials with an electrode bias voltage less than or equal to 5mV and an average drift rate less than or equal to 18±7mV / min in a stable state. The smaller the electrode bias voltage and the average drift rate in a stable state, the better the stability of the electrode material. In this embodiment, the Laplace electrode inner ring and the Laplace electrode outer ring are preferably made of materials with an electrode bias voltage less than or equal to 5mV and an average drift rate less than or equal to 18±7mV / min in a stable state, so that the performance of the active collection electrode is better.

[0097] As a possible implementation manner, the Laplace electrode inner ring 13 and the Laplace electrode outer ring 14 are made of silver-silver chloride material, disposable Ag / AgCl, silver, gold, platinum, stainless steel or tin.

[0098] In the active collection electrode provided in this embodiment, the inner ring of the Laplace electrode and the outer ring of the Laplace electrode are concentric ring structures. The inner ring of the electrode and the outer ring of the electrode are made of highly conductive and biocompatible materials such as silver-silver chloride material, disposable Ag / AgCl, silver, gold, platinum, stainless steel or tin, which can significantly improve the service life and signal quality of the electrode.

[0099] As a possible implementation, the area of ​​the inner ring 13 of the Laplace electrode is S1, the area of ​​the outer ring 14 of the Laplace electrode is S2, and S2 / S1=1.5-11.4; for example, 1.4, 7.9, 9, 11.4.

[0100] See also Figure 8 As a possible implementation, the radius of the Laplace electrode inner ring 13 is Rs, Rs≤4mm; the inner diameter of the Laplace electrode outer ring 14 is Ri, Rs<Ri≤8mm; the outer diameter of the Laplace electrode outer ring 14 is Ro, Ri<Ro≤12mm.

[0101] For example, Rs is 4 mm, Ri is 8 mm, and Ro is 12 mm, in which case S2 / S1=7.9; or Rs is 2.2 mm, Ri is 7 mm, and Ro is 10 mm, in which case S2 / S1=11.4; or Rs is 1 mm, Ri is 4 mm, and Ro is 5 mm, in which case S2 / S1=9.

[0102] As an example, the area ratio of the Laplace electrode outer ring 14 to the Laplace electrode inner ring 13 may also be S2 / S1=1-1.5; when S2 / S1=1, the areas of the inner ring and the outer ring are equal. Fig. 9 , the inner and outer rings of the Laplace electrode are equivalent to input resistances. From U=I*R, it can be seen that the common-mode signals of the inner and outer rings are equal, otherwise they will be interfered by the amplifier. The best output result is that the differential-mode signal of the inner and outer rings is the largest, and the differential-mode signal is determined by the resistor R. ρ is the resistivity of the material in Ω·cm, S is the cross-sectional area of ​​the material in cm 2 , l represents the length of the material, in cm; it can be seen that the resistance can be equal only when the area S is equal. Therefore, when S2 / S1=1, that is, the area of ​​the inner ring and the outer ring is equal, the signal loss is minimal, but in this case, the complexity of the electrode manufacturing process is greatly increased, and it is difficult to apply to mass production.

[0103] In order to avoid the active collection electrode being too large, the present invention does not set the size of the Laplace electrode inner ring 13 and the Laplace electrode outer ring 14 too large to avoid the problem of poor contact between the electrode and the subject's scalp. In addition, the embodiment of the present invention optimizes the radius and area ratio of the Laplace electrode inner ring and the Laplace electrode outer ring, and uses the original signal collected by the optimized electrode to perform differential processing to obtain a differential mode signal. In this way, the common mode signal interference to the differential mode signal is low, and the radius and area ratio provided by this embodiment are simpler and easier to implement for the manufacturing process of the active collection electrode, and can be applied to large-scale industrial production.

[0104] See also Fig.10 As an example, the active reference electrode fully considers the compatibility with the existing general amplifiers and realizes the connection with various types of general amplifiers in a common reference manner. That is, the inner ring of the Laplace electrode is connected to the reference end of the amplifier, so that the amplifier can receive the analog signal of the active acquisition electrode and perform digital-to-analog conversion on the analog signal to obtain EEG data, which greatly expands the application scope of the active reference electrode.

[0105] See also Fig.11 , is the comparative experimental result of measuring the self-noise of the system when the input terminal is short-circuited, Fig.11 (a) is the noise when directly collecting using a general purpose amplifier (NEU). Fig.11 (b) is the noise equivalent to the input end after adding the active collection electrode (ACC) of this embodiment to the front end of the general amplifier. By comparison, it can be seen that adding the active collection electrode effectively reduces the noise, which is about 6 times lower than not adding the active collection electrode, indicating that the active collection electrode of the present invention can greatly improve the clarity and reliability of signal collection.

[0106] See also Fig.12 , is the result of a comparative experiment with a standard sinusoidal signal source placed at the input end. Fig.12 (a) is the signal waveform display when directly using the universal amplifier (NEU) to collect. Fig.12 (b) is the signal waveform after being processed by the active collection electrode (ACC) of this embodiment. Fig.12 The waveform of (a) is obviously distorted, while Fig.12 The waveform of (b) is basically consistent with the standard sinusoidal signal, which shows that the active collection electrode of the present invention can significantly improve the fidelity of the signal, making the collection of weak signals more accurate.

[0107] In a second aspect, an embodiment of the present invention provides a charging device, which charges one or more active collection electrodes provided in the first aspect;

[0108] See also Figure 13 to Figure 14 The charging device 2 includes a charging base 20, a charging circuit board 21 and a charging cover 22 stacked from bottom to top; wherein the charging circuit board 21 is provided with a power supply interface 210, a plurality of groups of retractable charging contacts 211, and a switch 212 is provided corresponding to each group of charging contacts 211; illustratively, the switch 212 is a toggle switch, which can control the opening or closing of charging of each corresponding charging contact 211, and the power supply interface 210 can be controlled to charge the charging contacts 211 through the switch 212, that is, one or more of the charging contacts 211 can be selected to be charged;

[0109] See also Fig.13 , a plurality of charging areas 220 are arranged on the charging cover plate 22, each charging area 220 corresponds to a group of charging contacts 211, that is, each group of charging contacts 211 penetrates the cover plate where the charging area 220 is located and can be controllably extended and retracted;

[0110] See also Figures 15 to 17 In the charging state, the contact seat 102 magnetically attracts the charging contact 211, and the retractable part at the top of the charging contact 211 is compressed into the inside of the non-retractable part, so that the contact seat 102 and the charging contact 211 are fully in contact to achieve connection; illustratively, the charging contact has a built-in spring to achieve the retractability of the charging contact. Fig.18 , which is the charging circuit of the charging device. After the contact seat 102 magnetically attracts the charging contact 211, the positive and negative poles of the rechargeable battery are respectively connected to the BAT+ and BAT- terminals of the charging circuit to form a pathway, thereby realizing charging of the rechargeable battery. The OD and OC terminals are protection terminals to prevent charging overload, reverse charging, circuit overheating, etc., thereby ensuring charging safety without damaging the rechargeable battery.

[0111] The charging device provided in this embodiment can charge multiple active collection electrodes at the same time, which can solve the problem of frequent battery replacement of traditional electrodes. The charging device adopts a magnetic charging design, and the user only needs to place the electrode in the charging area to complete the charging operation. It is convenient and efficient, and extends the working time of the active collection electrode. It can improve the continuity and stability of the electrode during long-term work, and significantly improve the overall work efficiency.

[0112] In a third aspect, an embodiment of the present invention provides an electroencephalogram acquisition system, see Fig.19 ,include:

[0113] Display 3, used to present the stimulation paradigm interface;

[0114] The active collection electrode 1 is the active collection electrode 1 provided in the first aspect, and is attached to the head of the subject through an insulating patch; the inner ring radius Rs of the Laplace electrode is 3 mm, the inner ring diameter Ri of the Laplace electrode is 7 mm, and the outer ring diameter Ro of the Laplace electrode is 10 mm; the amplification factor of the amplification module on the active circuit board is 45, and the parameters of the bandpass filter module are 0.01 Hz to 100 Hz, for example, 0.01 Hz, 0.5 Hz, 50 Hz, and 100 Hz;

[0115] Amplifier 4, see Fig.10 The amplifier and the active collection electrode are electrically connected in a common reference connection manner, that is, the inner ring of the Laplace electrode is connected to the reference end of the amplifier; the analog signal of the active collection electrode is received, and the analog signal is converted into digital-to-analog form to obtain the EEG data;

[0116] The host computer 5 receives the EEG data, processes the EEG data and displays it.

[0117] See also Fig.19 As an example, the workflow of the EEG acquisition system is as follows:

[0118] 1) Sequentially attaching active acquisition electrodes 1 to the left occipital region and the right occipital region of the subject's head through insulating patches, and forming a signal acquisition unit by combining the Laplace electrode inner ring and the Laplace electrode outer ring;

[0119] 2) Display 3 presents the subject with a white (circle, square, triangle, etc.) stimulus that flashes rapidly;

[0120] 3) The EEG signal collected by the outer ring of the Laplace electrode is differentially processed with the reference signal of the inner ring of the Laplace electrode, and then amplified and band-pass filtered through the active circuit board to eliminate interference, and the EEG signal enters the amplifier 4;

[0121] 4) Amplifier 4 performs analog-to-digital conversion on the EEG signal to form EEG data and transmit it to the host computer 5;

[0122] 5) The host computer 5 performs Fourier transform on the EEG data to generate a spectrum diagram and display it.

[0123] In a fourth aspect, an embodiment of the present invention provides an electroencephalogram acquisition system, see Fig. 20 ,include:

[0124] Display 3, used to present the stimulation paradigm interface;

[0125] EEG acquisition headband 6, see Fig.21The EEG acquisition headband 6 is preset with a plurality of mounting holes for active acquisition electrodes 1, each of which has an active acquisition electrode 1 embedded therein; the active acquisition electrode 1 is the active acquisition electrode 1 provided in the first aspect; the inner ring radius Rs of the Laplace electrode is 2 mm, the inner ring diameter Ri of the Laplace electrode is 6 mm, and the outer ring diameter Ro of the Laplace electrode is 9 mm; the amplification factor of the amplification module on the active circuit board is 45, and the parameters of the bandpass filter module are 0.01 Hz to 100 Hz, for example, 0.01 Hz, 1 Hz, 45 Hz, 100 Hz;

[0126] Amplifier 4, see Fig.10 The amplifier 4 is electrically connected to the active collection electrode 1 in a common reference connection manner, that is, the inner ring of the Laplace electrode is connected to the reference end of the amplifier; the analog signal of the active collection electrode is received, and the analog signal is converted into digital-to-analog form to obtain the EEG data;

[0127] The host computer 5 receives the EEG data, processes the EEG data and displays it.

[0128] See also Fig. 20 As an example, the workflow of the EEG acquisition system is as follows:

[0129] 1) Fix the active collection electrode 1 in the installation positioning hole of the EEG collection headband 6, and form a signal collection unit by combining the Laplace electrode inner ring and the Laplace electrode outer ring;

[0130] 2) Wear the EEG acquisition headband 6 on the subject's head, and adjust the tightness of the headband to ensure good contact between the electrodes and the scalp;

[0131] 3) Display 3 presents visual stimulation signals (such as flashing graphics, color changes, or moving targets) to the subject;

[0132] 4) The EEG signal collected by the outer ring of the Laplace electrode is differentially processed with the reference signal of the inner ring of the Laplace electrode, and then amplified and band-pass filtered through the active circuit board to eliminate interference, and the EEG signal enters the amplifier 4;

[0133] 5) The amplifier 4 performs analog-to-digital conversion on the EEG signal to form EEG data and transmits it to the host computer 5;

[0134] 6) The host computer 5 extracts features and classifies the EEG data by applying feature extraction and pattern recognition algorithms such as TRCA (task-related component analysis) and DCPM (differential spatial pattern matching) to determine the target that the subject is looking at or the operation being performed;

[0135] 7) Feedback the calculation results of the host computer 5 to the visual presentation module of the display 3 in real time to execute corresponding operation instructions, such as controlling the movement of the cursor or executing other external device operations.

[0136] In a fifth aspect, the present invention provides another EEG acquisition system, see Fig. 22 ,include:

[0137] Display 3, used to present the stimulation paradigm interface;

[0138] Electrode cap 7, see Fig.23 The electrode cap 7 is composed of a plurality of active acquisition electrodes 1 connected via an expansion interface; the active acquisition electrode 1 is the active acquisition electrode 1 provided in the first aspect, and is pasted on the subject's head through an insulating patch; the radius Rs of the inner ring of the Laplace electrode is 1mm, the inner diameter Ri of the outer ring of the Laplace electrode is 4mm, and the outer diameter Ro of the outer ring of the Laplace electrode is 5mm; the amplification factor of the amplification module on the active circuit board is 45, and the parameters of the bandpass filter module are 0.01Hz to 100Hz, such as 0.01Hz, 0.5Hz, 45Hz, 100Hz; the EEG acquisition cap is composed of a plurality of active acquisition electrodes, which can significantly improve the spatial resolution and signal-to-noise ratio of the acquisition signal. Compared with the traditional EEG cap with a fixed number of leads, this design is highly flexible, capable of multi-channel acquisition for different areas of the whole brain, and any number of electrode arrangements can be selected according to needs to restore brain activity more comprehensively and accurately.

[0139] Amplifier 4, see Fig.10 The amplifier 4 is electrically connected to each active collection electrode 1 in a common reference connection manner, that is, the inner ring of the Laplace electrode is connected to the reference end of the amplifier; the analog signal of the active collection electrode is received, and the analog signal is converted into digital-to-analog form to obtain the EEG data;

[0140] The host computer 5 receives the EEG data, processes the EEG data and displays it.

[0141] See also Fig. 22 As an example, the workflow of the EEG acquisition system is as follows:

[0142] 1) An elastic band is used to connect multiple active collection electrodes to form an electrode cap 7, and the brain electrode cap 7 is worn on the subject's head, and a signal collection unit is formed by combining a Laplace electrode inner ring and a Laplace electrode outer ring;

[0143] 2) Multiple active collection devices are attached to the subject's head through insulating patches to ensure good contact between the electrodes and the scalp;

[0144] 3) Display 3 presents visual stimulation signals (such as flashing graphics, color changes, or moving targets) to the subject;

[0145] 4) The EEG signal collected by the outer ring of the Laplace electrode is differentially processed with the reference signal of the inner ring of the Laplace electrode, and then amplified and band-pass filtered through the active circuit board to eliminate interference, and the EEG signal enters the amplifier 4;

[0146] 5) The amplifier 4 performs analog-to-digital conversion on the EEG signal to form EEG data and transmits it to the host computer 5;

[0147] 6) The host computer 5 extracts features and classifies the EEG data by applying feature extraction and pattern recognition algorithms such as TRCA (task-related component analysis) and DCPM (differential spatial pattern matching) to determine the target that the subject is looking at or the operation being performed;

[0148] 7) Feedback the calculation results of the host computer 5 to the visual presentation module of the display 3 in real time to execute corresponding operation instructions, such as controlling the movement of the cursor or executing other external device operations.

[0149] In a sixth aspect, an embodiment of the present invention provides an application method of an EEG acquisition system. After configuring the EEG acquisition system provided by any one of the third aspect to the fifth aspect, the following steps are performed:

[0150] An active collection electrode is worn on the subject's head, and the Laplace electrode inner ring and the Laplace electrode outer ring are combined to form a signal collection unit to obtain the subject's original EEG signal; the original EEG signal is a differential signal between the EEG signal collected by the Laplace electrode outer ring and the reference signal of the Laplace electrode inner ring; the differential signal is pre-amplified and filtered before being transmitted to the amplifier;

[0151] Active collection electrodes are worn on the front or back of the subject's head, and the subject performs EEG induction according to the prompts on the display;

[0152] The amplifier amplifies the differential signal output by the active acquisition electrode and obtains EEG data after analog-to-digital conversion;

[0153] The host computer receives computer data, processes and displays the EEG data.

[0154] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the drawings, etc. In the specification, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit can implement several functions listed in the specification. Certain measures are recorded in different embodiments, but this does not mean that these measures cannot be combined to produce good results.

[0155] Although the present invention has been described in conjunction with specific features and embodiments thereof, it is apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the present invention. Accordingly, this specification and the accompanying drawings are merely exemplary illustrations of the present invention and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the present invention. Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, the present invention is intended to include such modifications and variations if they fall within the scope of the present invention and its equivalents.

Claims

1. An active collection electrode, characterized in that: include: A rechargeable power supply assembly, an active circuit board, an electrode base, a Laplace electrode inner ring, a Laplace electrode outer ring, and an insulating patch; The rechargeable power supply component supplies power to the active circuit board; the electrode base is located on the rechargeable power supply component; The electrode base has an annular accommodation space at one end away from the rechargeable power supply assembly; The inner ring of the Laplace electrode is accommodated in the inner ring space of the annular accommodation space, and the outer ring of the Laplace electrode is accommodated in the outer ring space of the annular accommodation space; the inner ring of the Laplace electrode and the outer ring of the Laplace electrode are directly connected to the active circuit board; The active circuit board is provided with an amplification module, a high-pass filter module and a low-pass filter module to sequentially amplify and filter the differential signals of the inner ring of the Laplace electrode and the outer ring of the Laplace electrode; the active circuit board is also provided with a voltage stabilization module to stabilize the voltage provided by the rechargeable power supply component; The insulating patch is attached to the electrode base and isolates the inner ring of the Laplace electrode from the outer ring of the Laplace electrode.

2. The active collection electrode according to claim 1, characterized in that: The Laplace electrode inner ring and the Laplace electrode outer ring are made of materials with an electrode bias voltage less than or equal to 5mV and an average drift rate less than or equal to 18±7mV / min in a stable state.

3. The active collection electrode according to claim 1, characterized in that: The inner ring of the Laplace electrode and the outer ring of the Laplace electrode are made of silver-silver chloride material, disposable Ag / AgCl, silver, gold, platinum, stainless steel or tin.

4. The active collection electrode according to claim 1, characterized in that: The area of ​​the inner ring of the Laplace electrode is S1, the area of ​​the outer ring of the Laplace electrode is S2, and S2 / S1=1.5-11.

4.

5. The active collection electrode according to claim 4, characterized in that: The radius of the inner ring of the Laplace electrode is Rs, Rs≤4mm; the inner diameter of the outer ring of the Laplace electrode is Ri, Rs<Ri≤8mm; the outer diameter of the outer ring of the Laplace electrode is Ro, Ri<Ro≤12mm.

6. The active collection electrode according to claim 1, characterized in that: The rechargeable power supply assembly includes a protective shell, a rechargeable battery and a contact seat; wherein the rechargeable battery and the active circuit board are stacked up and down in a detachable manner and are fastened to the protective shell; one end of the contact seat is fastened to the active circuit board to connect the positive and negative power interfaces of the rechargeable battery, and the other end of the contact seat is connected to the charging contact of the charging device to connect the charging circuit board in the charging device; and / or, An extension interface is provided longitudinally through the extension of the electrode base.

7. A charging device, characterized in that: The charging device charges one or more active collection electrodes as described in any one of claims 1 to 6; The charging device comprises a charging base, a charging circuit board and a charging cover plate stacked from bottom to top; wherein the charging circuit board is provided with a power supply interface, a plurality of groups of retractable charging contacts, and a switch is provided for each group of charging contacts; the power supply interface is controllable by the switch to charge the charging contacts; The charging cover is provided with a plurality of charging areas, each of which corresponds to a set of charging contacts, that is, each set of charging contacts penetrates the cover where the charging area is located and can be controllably extended and retracted; In the charging state, the contact seat magnetically attracts the charging contact to achieve connection.

8. An electroencephalogram acquisition system, characterized in that: include: A display for presenting the stimulus paradigm interface; An active collection electrode, wherein the active collection electrode is the active collection electrode according to any one of claims 1 to 6, and is attached to the head of a subject through an insulating patch; the inner ring radius Rs of the Laplace electrode is 3 mm, the inner ring diameter Ri of the Laplace electrode is 7 mm, and the outer ring diameter Ro of the Laplace electrode is 10 mm; the amplification factor of the amplification module on the active circuit board is k times, 1<k<45; the parameters of the bandpass filter module are within the range of 0.01 Hz to 100 Hz; The amplifier is connected to the active collection electrode in a common reference connection mode, that is, the inner ring of the Laplace electrode is connected to the reference end of the amplifier; receives the analog signal of the active collection electrode, and obtains the EEG data after performing digital-to-analog conversion on the analog signal; The host computer receives the EEG data, processes the data and displays it.

9. An electroencephalogram acquisition system, characterized in that: include: A display for presenting the stimulus paradigm interface; An EEG acquisition headband, wherein the EEG acquisition headband is preset with a plurality of mounting holes for active acquisition electrodes, each mounting hole is embedded with an active acquisition electrode; the active acquisition electrode is the active acquisition electrode according to any one of claims 1 to 6; the inner ring radius Rs of the Laplace electrode is 2 mm, the inner ring diameter Ri of the Laplace electrode is 6 mm, and the outer ring diameter Ro of the Laplace electrode is 9 mm; the amplification factor of the amplification module on the active circuit board is k times, 1<k<45; the parameters of the bandpass filter module are within the range of 0.01 Hz to 100 Hz; The amplifier is connected to the active collection electrode in a common reference connection mode, that is, the inner ring of the Laplace electrode is connected to the reference end of the amplifier; receives the analog signal of the active collection electrode, and obtains the EEG data after performing digital-to-analog conversion on the analog signal; The host computer receives the EEG data, processes the data and displays it.

10. An electroencephalogram acquisition system, characterized in that: include: A display for presenting the stimulus paradigm interface; An electrode cap, wherein the electrode cap is composed of a plurality of active collection electrodes connected via an expansion interface; the active collection electrode is the active collection electrode according to any one of claims 1 to 6, and is attached to the subject's head via an insulating patch; the inner ring radius Rs of the Laplace electrode is 1 mm, the inner ring diameter Ri of the Laplace electrode is 4 mm, and the outer ring diameter Ro of the Laplace electrode is 5 mm; the amplification factor of the amplification module on the active circuit board is k times, 1<k<45; the parameters of the bandpass filter module are within the range of 0.01 Hz to 100 Hz; The amplifier is connected to the active collection electrode in a common reference connection mode, that is, the inner ring of the Laplace electrode is connected to the reference end of the amplifier; receives the analog signal of the active collection electrode, and obtains the EEG data after performing digital-to-analog conversion on the analog signal; The host computer receives the EEG data, processes the data and displays it.

11. An application method of an electroencephalogram acquisition system, characterized in that: After configuring the EEG acquisition system as described in any one of claims 8 to 10, perform the following steps: The active collection electrode is worn on the subject's head, and the Laplace electrode inner ring and the Laplace electrode outer ring are combined to form a signal collection unit to obtain the subject's original EEG signal; The original EEG signal is a differential signal between the EEG signal collected by the outer ring of the Laplace electrode and the reference signal of the inner ring of the Laplace electrode; the differential signal is transmitted to the amplifier after being pre-amplified and filtered; Active collection electrodes are worn on the front or back of the subject's head, and the subject performs EEG induction according to the prompts on the display; The amplifier amplifies the differential signal output by the active acquisition electrode and obtains EEG data after analog-to-digital conversion; The host computer receives computer data, processes and displays the EEG data.

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