Active collection electrode, charging device, EEG collection system and application method

Abstract

The present invention relates to the field of brain-computer interface technology, and discloses an active acquisition electrode, a charging device, an EEG acquisition system, and an application method. The active acquisition electrode includes: 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; 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, and the Laplace electrode inner ring and the Laplace electrode outer ring are respectively accommodated in the inner ring space and the outer ring space of the annular accommodation space, and are enclosed by an insulating patch. The active circuit board is equipped with an amplification module, a high-pass filter module, a low-pass filter module, and a voltage stabilization module. The present invention can achieve common reference connection with a variety of general amplifiers, has a wide range of applications, and the electrode itself can directly perform preliminary amplification and filtering processing on the signal at the signal source, which can improve the signal-to-noise ratio and overall stability of the acquired signal.

Description

Technical Field

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

[0002] A brain-computer interface (BCI) is a system that directly converts central nervous system (CNS) activity into artificial output, aiming to improve the interaction between the CNS and the external environment. A typical BCI system usually consists of four main components: 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 effectiveness of subsequent signal processing, and therefore plays a vital role in BCI systems.

[0003] In the signal acquisition process, 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 the activity of cortical neurons by placing electrodes on the surface of the scalp. 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 scalp surface, EEG signals are 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, which makes the collected EEG signals not only have 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 that adds a preamplifier circuit to the traditional disk electrode to perform preliminary amplification at the signal acquisition source to reduce interference. However, this active electrode has the following drawbacks:

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

[0006] 2) Due to the addition of a preamplifier circuit, this type of electrode requires separate power lines and signal transmission lines when laying out, 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 overall ease of use and stability.

[0007] 3) The active electrode requires an independent reference electrode for 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 significant influence of voltage fluctuations.

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

[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 assembly supplies power to the active circuit board; the electrode base is located on the rechargeable power supply assembly; an annular accommodation space is provided at one end of the electrode base away from the rechargeable power supply assembly; an inner ring of the Laplace electrode is accommodated in the inner ring space of the annular accommodation space, and an 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; an amplification module, a high-pass filtering module, and a low-pass filtering module are configured on the active circuit board 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 configured with a voltage stabilization module to stabilize the voltage provided by the rechargeable power supply assembly;

[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 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 manner, 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, 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, a rechargeable power supply assembly includes a protective housing, a rechargeable battery, and a contact holder; wherein the rechargeable battery and the active circuit board are both detachably stacked and securely connected within the protective housing; one end of the contact holder is securely connected 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 holder is connected to the charging contacts of a 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 for charging 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 stacked from bottom to top. The charging circuit board is equipped with a power supply interface, multiple sets of retractable charging contacts, and a switch corresponding to each set of charging contacts. The power supply interface charges the charging contacts in a controlled manner via 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 passes through the cover where the charging area is located and can be controllably extended and retracted.

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

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

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

[0028] An active collection electrode, which is the active collection electrode provided in the first aspect, is attached to the subject's head via 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 amplifier module on the active circuit board is k times, 1 < k < 45; and 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 from the active collection electrode and obtains EEG data after performing digital-to-analog conversion on the analog signal;

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

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

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

[0033] An EEG acquisition headband is provided with a plurality of mounting holes for active acquisition electrodes, each of which is embedded with an active acquisition electrode. The active acquisition electrodes are those provided in the first aspect. The inner radius Rs of the Laplace electrode is 2 mm, the inner diameter Ri of the outer ring of the Laplace electrode is 6 mm, and the outer diameter Ro of the outer ring of the Laplace electrode is 9 mm. The amplification factor of the amplifier module on the active circuit board is k times, where 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 from the active collection electrode and obtains EEG data after performing digital-to-analog conversion on the analog signal;

[0035] The host computer receives the EEG data, processes it 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, comprising a plurality of active collection electrodes connected via an expansion interface; the active collection electrodes are those provided in the first aspect and are 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 amplifier module on the active circuit board is k times, where 1 < k < 45; and 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 obtain EEG data after performing digital-to-analog conversion on the analog signal;

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

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

[0042] Active collection electrodes are placed on the subject's head. The inner and outer Laplace electrode rings form a signal collection unit to acquire the subject's original EEG signal. The original EEG signal is the difference between the EEG signal collected by the outer Laplace electrode ring and the reference signal of the inner Laplace electrode ring. The differential signal is pre-amplified and filtered before being transmitted to an 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 the EEG data and displays it.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] 1. The active collection electrode provided by this invention fully considers compatibility with existing general-purpose amplifiers, enabling connection to a variety of common amplifier types using a common reference method. Specifically, the inner ring of the Laplace electrode is connected to the reference terminal of the amplifier. This allows the amplifier to receive the analog signal from the active collection electrode and perform digital-to-analog conversion to obtain EEG data, significantly expanding the application range of the active reference electrode.

[0048] 2. Unlike traditional disc electrodes, the active acquisition electrode provided by the present invention is a bipolar concentric ring structure. The inner ring of the Laplace electrode is used as the 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 contamination problem introduced by independent reference electrodes. It can significantly improve the signal quality in the multi-channel acquisition process, enhance the reliability of EEG signal acquisition, and help improve the spatial resolution of EEG signals.

[0049] 3. The active collection electrode proposed in this invention has an inner and outer ring made of highly conductive and biocompatible materials such as silver-silver chloride, disposable Ag / AgCl, silver, gold, platinum, stainless steel, or tin, which can significantly improve the service life of the electrode and signal quality.

[0050] 4. The present invention optimizes the radius and area ratio of the inner and outer Laplace electrode rings. The original signal collected by the optimized electrodes is differentially processed to obtain a differential-mode signal. This arrangement reduces common-mode signal interference with the differential-mode signal. Furthermore, the radius and area ratio of the inner and outer Laplace electrode rings provided by the present invention simplifies the manufacturing process of active collection electrodes and is suitable for large-scale industrial production.

[0051] 5. The active acquisition electrode provided by the present invention is equipped with an amplification module, a high-pass filtering module and a low-pass filtering 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 acquisition electrodes provided by the present invention adhere the electrodes to the subject's head via an insulating patch, ensuring close contact between the electrodes and the subject's scalp, improving the subject's comfort, and allowing for flexible placement on the subject's head. The electrodes of the present invention are simple to secure, making them easy to install and remove. The electrode base includes an expansion port that allows for flexible adjustment of the number and position of electrodes based on specific needs. This improves the flexibility of electrode placement during multi-channel EEG signal acquisition and provides a more convenient multi-channel signal acquisition solution for complex experimental scenarios.

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

[0054] 8. The active acquisition electrodes provided by the present invention can be applied to a variety of EEG acquisition 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 accompanying 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 accompanying drawings:

[0056] Figure 1 This is a schematic diagram of the active collection electrode structure 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 A schematic diagram of a signal processing path formed by two rings of Laplace electrodes, an active circuit board, and a charging assembly in accordance with an embodiment of the present invention;

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

[0060] Figure 5 A schematic diagram of the optional shapes of the active circuit board in an embodiment of the present invention;

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

[0062] Figure 7 This is 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 and outer ring of the Laplace electrode in an embodiment of the present invention;

[0064] Figure 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] Figure 10 Schematic diagram of the connection between the active collection electrode and the universal amplifier in a common reference manner in an embodiment of the present invention;

[0066] Figure 11 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] Figure 12 This is a schematic diagram of the experimental results of signal waveform comparison performed by placing a standard sinusoidal signal source at the input end in an embodiment of the present invention;

[0068] Figure 13 This is a schematic structural diagram of a charging device in an embodiment of the present invention;

[0069] Figure 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] Figure 15 This is a schematic diagram of inserting an active collection electrode into a charging device in an embodiment of the present invention;

[0071] Figure 16 A cross-sectional view of an active collection electrode inserted into a charging device according to an embodiment of the present invention;

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

[0073] Figure 18 Schematic diagram of a charging circuit of a charging device according to an embodiment of the present invention;

[0074] Figure 19 This is a schematic diagram of an EEG acquisition system provided in the third aspect of an embodiment of the present invention;

[0075] Figure 20 A schematic diagram of an EEG acquisition system provided in accordance with a fourth aspect of an embodiment of the present invention;

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

[0077] Figure 22 This is a schematic diagram of an EEG acquisition system provided in the fifth aspect of an embodiment of the present invention;

[0078] Figure 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 assembly, 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] To facilitate a clear description of the technical solutions of the embodiments of the present invention, the words "first" and "second" are used in the embodiments of the present invention to distinguish between identical or similar items with substantially the same functions and effects. For example, the first threshold and the second threshold are merely used to distinguish between different thresholds and do not limit their order. Those skilled in the art will understand that the words "first" and "second" do not limit the quantity or execution order, and the words "first" and "second" do not necessarily mean 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 construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0085] In the present invention, "at least one" refers to one or more, and "more" refers to 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 represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. The following at least one item (item) 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 (item) of a, b or c can represent: 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 public reference pollution, and significant influence of voltage fluctuations.

[0087] In the first aspect, the embodiment of the present invention provides an active collection electrode, see Figure 1 The active collection electrode 1 includes: 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 structure. The inner ring of the Laplace electrode serves as the 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 contamination problem introduced by independent reference electrodes, significantly improving the signal quality in the multi-channel acquisition process, enhancing 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 uses the differential signal of the Laplace electrode inner ring 13 and the Laplace electrode outer ring 14 as input, see Figure 4The positive input of the active circuit is connected to the outer ring 14 of the Laplace electrode, and the negative input 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, it passes through the high-pass filter module and the low-pass filter module to weaken the influence of low-frequency interference, baseline drift and high-frequency noise, ensuring high-quality transmission of the signal within the effective frequency band and improving the stability and accuracy of signal acquisition. In addition, the active circuit board 11 is also equipped with a voltage stabilization module to convert the voltage provided by the rechargeable power supply component 10 into the required stable voltage. Such a design enables the electrode itself to directly perform preliminary amplification and filtering of the signal at the signal source, which can significantly reduce the impact 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 serves as a base component, and its shape can be any shape such as square, round, polygonal, etc. The present invention does not make specific limitations, 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 assembly 10 includes a protective shell 100, a rechargeable battery 101, and a contact socket 102. The rechargeable battery 101 and the active circuit board 11 are both detachably stacked and securely connected within the protective shell 100. The protective shell 100 is used to secure the active circuit board 11 and provide positioning and support for the contact socket 102. The rechargeable battery 101 (e.g., a lithium battery) is used to provide a low-noise, linear, and stable voltage to the active circuit board 11 to reduce electrical noise interference. One end of the contact socket 102 is securely connected to the active circuit board 11 to connect to the positive and negative power supply interfaces, and the other end of the contact socket 102 is connected to the charging contacts of the charging device to connect to the charging circuit board in the charging device. Alternatively, an extension interface 120 is provided longitudinally extending through the extension of the electrode base 12. The active collection electrode provided in this embodiment is powered by an independent rechargeable battery 101 within the rechargeable power supply assembly 10, eliminating the need for a power cable, eliminating interference issues caused by power cables, and improving flexibility.

[0092] See also Figure 1 and Figure 6The electrode base 12 is provided with an annular accommodation space for accommodating the inner Laplace electrode ring 13 and the outer Laplace electrode ring 14. The insulating patch 15 is attached to the electrode base 12 and isolates the inner Laplace electrode ring 13 from the outer Laplace electrode ring 14. In actual application, the insulating patch 15 can be made of double-sided adhesive tape. The insulating patch 15 is used to attach the electrode to the subject's head. This not only ensures close contact between the electrode and the subject's scalp, but also improves the subject's comfort and allows for flexible placement 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 detachable bolts 16, which fasten the electrode structure and facilitate quick disassembly.

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

[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 and outer ring of the Laplace electrode are concentric ring structures. The inner ring and 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 Laplace electrode ring 13 is S1, the area of ​​the outer Laplace electrode ring 14 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, then S2 / S1=7.9; or, Rs is 2.2 mm, Ri is 7 mm, and Ro is 10 mm, then S2 / S1=11.4; or Rs is 1 mm, Ri is 4 mm, and Ro is 5 mm, then S2 / S1=9.

[0102] As an example, the area ratio of the Laplace electrode outer ring 14 to the Laplace electrode inner ring 13 can also be S2 / S1=1-1.5; when S2 / S1=1, the areas of the inner ring and the outer ring are equal. Figure 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 only be equal when the area S is equal. Therefore, when S2 / S1 = 1, that is, the area of ​​the inner and outer rings is equal, the signal loss is minimized. However, this greatly increases the complexity of the electrode manufacturing process, making it difficult to apply to mass production.

[0103] To prevent the active acquisition electrodes from being too large, the present invention does not oversize the inner and outer Laplace electrode rings 13 and 14, thereby preventing poor contact between the electrodes and the subject's scalp. Furthermore, the present embodiment optimizes the radius and area ratio of the inner and outer Laplace electrode rings. The original signal collected by the optimized electrodes is differentially processed to obtain a differential-mode signal. This arrangement minimizes common-mode signal interference with the differential-mode signal. Furthermore, the radius and area ratio provided by this embodiment simplify the manufacturing process for the active acquisition electrodes, making them suitable for mass industrial production.

[0104] See also Figure 10 As an example, active reference electrodes take full account of compatibility with existing general-purpose amplifiers, enabling them to connect to a variety of different types of general-purpose amplifiers using a common reference method. Specifically, the inner ring of the Laplace electrode is connected to the reference terminal of the amplifier. This allows the amplifier to receive the analog signal from the active acquisition electrode and perform digital-to-analog conversion to obtain EEG data, greatly expanding the application range of active reference electrodes.

[0105] See also Figure 11 , is the comparative experimental result of measuring the self-noise of the system when the input terminal is short-circuited. Figure 11 (a) is the noise when directly collecting using a general-purpose amplifier (NEU). Figure 11 Figure (b) shows the noise equivalent to the input end after adding the active collection electrode (ACC) of this embodiment to the front end of a general amplifier. This comparison shows that the addition of the active collection electrode effectively reduces noise by approximately six times compared to the absence of the active collection electrode, demonstrating that the active collection electrode of the present invention can significantly improve the clarity and reliability of signal acquisition.

[0106] See also Figure 12 , is the result of a comparative experiment with a standard sinusoidal signal source placed at the input. Figure 12 (a) shows the signal waveform when directly using a universal amplifier (NEU). Figure 12 (b) is the signal waveform after being processed by the active collection electrode (ACC) of this embodiment. Figure 12 The waveform of (a) is obviously distorted, while Figure 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 for charging one or more active collection electrodes provided in the first aspect;

[0108] See also Figures 13 and 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, multiple groups of retractable charging contacts 211, and a switch 212 corresponding to each group of charging contacts 211; illustratively, the switch 212 is a toggle switch that can control the charging of each corresponding charging contact 211 to be turned on or off. The power supply interface 210 can be controlled by the switch 212 to charge the charging contacts 211, that is, one or more charging contacts 211 can be selectively charged;

[0109] See also Figure 13 The charging cover 22 is provided with a plurality of charging areas 220 , each of which corresponds to a set of charging contacts 211 , that is, each set of charging contacts 211 passes through the cover 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 portion of the top of the charging contact 211 is compressed into the inside of the non-retractable portion, 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. Figure 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 charging the rechargeable battery. The OD and OC terminals are protection terminals to prevent charging overload, reverse charging, circuit overheating, etc., 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. In addition, this charging device adopts a magnetic charging design. Users only need to place the electrodes in the charging area to complete the charging operation. This is convenient and efficient, extends the working time of the active collection electrodes, and can improve the continuity and stability of the electrodes during long-term work, significantly improving overall work efficiency.

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

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

[0114] An active acquisition electrode 1, which is the active acquisition electrode 1 provided in the first aspect, is attached to the subject's head via an insulating patch; the inner ring radius Rs of the Laplace electrode is 3 mm, the inner ring inner diameter Ri of the Laplace electrode is 7 mm, and the outer ring outer diameter Ro of the Laplace electrode is 10 mm; the amplification factor of the amplifier 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 Figure 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 Figure 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 and right occipital regions of the subject's head through insulating patches, and forming a signal acquisition unit by combining the inner and outer Laplace electrode rings;

[0119] 2) Display 3 presents the subject with a white stimulus (shaped like a circle, square, triangle, etc.) 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 by the active circuit board to eliminate interference. The EEG signal enters amplifier 4;

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

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

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

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

[0125] EEG acquisition headband 6, see Figure 21The EEG acquisition headband 6 is pre-set with multiple mounting holes for active acquisition electrodes 1, each of which is embedded with an active acquisition electrode 1; 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 diameter Ri of the outer ring of the Laplace electrode is 6 mm, and the outer diameter Ro of the outer ring of the Laplace electrode is 9 mm; the amplification factor of the amplifier 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, and 100 Hz;

[0126] Amplifier 4, see Figure 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 Figure 20 As an example, the workflow of the EEG acquisition system is as follows:

[0129] 1) Fix the active acquisition electrode 1 in the mounting hole of the EEG acquisition headband 6, and form a signal acquisition unit by combining the inner Laplace electrode ring and the outer Laplace electrode 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 by the active circuit board to eliminate interference. The EEG signal enters amplifier 4;

[0133] 5) The amplifier 4 performs analog-to-digital conversion on the EEG signal to generate 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 the subject is looking at or the action 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 Figure 22 ,include:

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

[0138] Electrode cap 7, see Figure 23 The electrode cap 7 is composed of multiple 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 attached to the subject's head via an insulating patch; the inner ring radius Rs of the Laplace electrode is 1mm, the inner ring inner diameter Ri of the Laplace electrode is 4mm, and the outer ring outer diameter Ro of the Laplace electrode is 5mm; the amplification factor of the amplifier module on the active circuit board is 45, and the parameters of the bandpass filter module are 0.01Hz to 100Hz, for example, 0.01Hz, 0.5Hz, 45Hz, and 100Hz; the EEG acquisition cap is composed of multiple active acquisition electrodes, which can significantly improve the spatial resolution and signal-to-noise ratio of the acquired signal. Compared with traditional EEG caps with a fixed number of leads, this design is highly flexible and can perform multi-channel acquisition for different areas of the entire brain. Any number of electrode arrangements can be selected according to needs to more comprehensively and accurately restore brain activity.

[0139] Amplifier 4, see Figure 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 Figure 22 As an example, the workflow of the EEG acquisition system is as follows:

[0142] 1) Using an elastic band to connect multiple active collection electrodes to form an electrode cap 7, the brain electrode cap 7 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;

[0143] 2) Multiple active collection electrodes 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 by the active circuit board to eliminate interference. The EEG signal enters amplifier 4;

[0146] 5) The amplifier 4 performs analog-to-digital conversion on the EEG signal to generate 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 the subject is looking at or the action 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 to fifth aspects, the following steps are performed:

[0150] Active collection electrodes are placed on the subject's head. The inner and outer Laplace electrode rings form a signal collection unit to acquire the subject's original EEG signal. The original EEG signal is the difference between the EEG signal collected by the outer Laplace electrode ring and the reference signal of the inner Laplace electrode ring. The differential signal is pre-amplified and filtered before being transmitted to an 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 the EEG data and displays it.

[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 can 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 with reference to specific features and embodiments thereof, it will be apparent that various modifications and combinations thereof may be made without departing from the spirit and scope of the invention. Accordingly, this specification and drawings are merely illustrative of the present invention and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the invention. It will be apparent that various modifications and variations of the present invention may be made by those skilled in the art without departing from the spirit and scope of the invention. Thus, the present invention is intended to include such modifications and variations as fall within the scope of the invention and its equivalents.

Claims

1. An active collection electrode, characterized in that: include: Rechargeable power supply assembly, active circuit board, electrode base, Laplace electrode inner ring, Laplace electrode outer ring and 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 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 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 equipped 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; 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; The inner ring radius 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; 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 detachably stacked and securely connected within the protective shell; one end of the contact seat is securely connected to the active circuit board to connect to the positive and negative power supply interfaces of the rechargeable battery, and the other end of the contact seat is connected to the charging contacts of the charging device to connect to the charging circuit board in the charging device; An extension interface is provided longitudinally through the extension of the electrode base.

2. The active collection electrode according to claim 1, characterized in that: The inner ring and outer ring of the Laplace electrode 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. A charging device, characterized in that: The charging device charges one or more active collection electrodes according to any one of claims 1 to 3; The charging device includes a charging base, a charging circuit board, and a charging cover stacked from bottom to top; wherein the charging circuit board is provided with a power supply interface, multiple sets of retractable charging contacts, and a switch corresponding to each set of charging contacts; the power supply interface is controlled by the switch to charge the charging contacts; 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 passes through 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.

5. An EEG 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 3, and is attached to the subject's head via 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 amplifier module on the active circuit board is k times, 1 < k < 45; and the parameters of the bandpass filter module are within the range of 0.01 Hz to 100 Hz; An amplifier is 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; receives the analog signal of the active collection electrode, and obtains EEG data after performing digital-to-analog conversion on the analog signal; The host computer receives the EEG data, processes it and displays it.

6. An EEG acquisition system, characterized in that: include: a display for presenting the stimulus paradigm interface; An EEG acquisition headband, wherein the headband is pre-set with multiple mounting holes for active acquisition electrodes, each mounting hole having an active acquisition electrode embedded therein; the active acquisition electrode is the active acquisition electrode according to any one of claims 1 to 3; 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, where 1 < k < 45; and the parameters of the bandpass filter module are within the range of 0.01 Hz to 100 Hz; An amplifier is 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; receives the analog signal of the active collection electrode, and obtains EEG data after performing digital-to-analog conversion on the analog signal; The host computer receives the EEG data, processes it and displays it.

7. An EEG acquisition system, characterized in that: include: a display for presenting the stimulus paradigm interface; An electrode cap, the electrode cap being composed of a plurality of active collection electrodes connected via an expansion interface; the active collection electrode being the active collection electrode according to any one of claims 1 to 3, and being adhered to the subject's head via an insulating patch; the inner ring radius Rs of the Laplace electrode being 1 mm, the inner ring diameter Ri of the Laplace electrode being 4 mm, and the outer ring diameter Ro of the Laplace electrode being 5 mm; the amplification factor of the amplification module on the active circuit board being k times, 1 < k < 45; and the parameters of the bandpass filter module being within the range of 0.01 Hz to 100 Hz; An amplifier is 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; receives the analog signal of the active collection electrode, and obtains EEG data after performing digital-to-analog conversion on the analog signal; The host computer receives the EEG data, processes it and displays it.

8. An application method of an EEG acquisition system, characterized in that: After configuring the EEG acquisition system according to any one of claims 5 to 7, perform the following steps: An active collection electrode is worn on the subject's head. The inner ring of the Laplace electrode and the outer ring of the Laplace electrode 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 pre-amplified and filtered before being transmitted to the amplifier; 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 the EEG data, processes the data and displays it.

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