A dual-channel claw-type EEG electrode

Abstract

This invention discloses a dual-channel claw-type EEG electrode, comprising a shell, an infusion mechanism, a first sensing contact, and a second sensing contact. The shell is covered with a sealing cap, which has a first channel for unidirectional input of conductive medium. The shell contains a cavity for the conductive medium to stagnate. Multiple first sensing contacts are arranged circumferentially around the shell, and the infusion mechanism is located at the bottom of the shell. The second sensing contact is fixed to the infusion mechanism. The first sensing contact communicates with the cavity through a second channel on the shell, and the second sensing contact communicates with the cavity through a third channel on the infusion mechanism. When the second sensing contact moves under external force, it causes the infusion mechanism to compress the cavity volume, thereby driving the power supply medium to be applied between the first sensing contact and the scalp through the second channel and between the second sensing contact and the scalp through the third channel, thus realizing a dual-channel function of acquisition and stimulation.

Description

Technical Field

[0001] This invention belongs to the field of brain-computer interface technology, and particularly relates to a dual-channel claw-type EEG electrode. Background Technology

[0002] Non-invasive EEG electrodes are sensors that record the physiological electrical activity of brain nerve tissue or input stimulation signals to scalp tissue. They are mainly placed on the surface of the scalp. EEG electrodes are classified into wet electrodes, semi-dry electrodes, and dry electrodes. Semi-dry electrodes are a type of electrode between wet and dry electrodes. By injecting a stored conductive fluid between the scalp and the electrode, the scalp-electrode impedance is reduced. Compared to wet electrodes, this effectively saves electrode deployment time. Theoretically, the signal quality of semi-dry electrodes is between that of dry and wet electrodes. However, the following problems still exist: 1) Due to the lack of convenient methods for replenishing or filling the conductive fluid, the effective battery life of EEG electrodes is relatively short; 2) Hair on the scalp surface hinders sufficient contact between the electrode and the scalp surface, causing high impedance and interface instability in the signal conduction circuit. Moreover, because the scalp surface is curved, the existing semi-dry electrodes have weak conformal contact ability with the curved scalp surface, which affects interface stability under motion interference, causing impedance fluctuations, motion artifacts, and reduced signal-to-noise ratio; 3) Existing EEG electrodes have a single function, only capable of unidirectional acquisition or reverse stimulation, and cannot perform both acquisition and stimulation functions at the same location. Summary of the Invention

[0003] To address the problems existing in the prior art, the present invention aims to provide a dual-path claw-type EEG electrode, which aims to solve the technical problems existing in the current semi-dry EEG electrodes: the conductive fluid injection method is singular, the application is inflexible, the effective acquisition time of EEG signals is short; the electrode cannot effectively pass through the hair obstruction, the conformal and reliable contact effect with the curved surface of the scalp tissue is poor, and the resistance to motion interference is weak; and the acquisition and stimulation functions cannot be performed at the same location.

[0004] To achieve the above objectives, the dual-channel claw-type EEG electrode of the present invention includes a shell, an infusion mechanism, a first sensing contact, and a second sensing contact. The shell is covered with a sealing cap, which has a first channel for unidirectional input of a conductive medium. The shell contains a cavity for the conductive medium to stagnate. Multiple first sensing contacts are arranged circumferentially on the shell, and the infusion mechanism is located at the bottom of the shell. The second sensing contact is fixed to the infusion mechanism. The first sensing contact communicates with the cavity through a second channel on the shell, and the second sensing contact communicates with the cavity through a third channel on the infusion mechanism. When the second sensing contact moves under external force, it causes the infusion mechanism to compress the cavity volume, thereby driving the power supply medium to be applied between the first sensing contact and the scalp via the second channel, and between the second sensing contact and the scalp via the third channel.

[0005] Furthermore, the infusion mechanism includes a telescopic sleeve, an elastic element, and a first unidirectional permeation membrane. The telescopic sleeve is slidably disposed within the outer shell and can move up and down along the vertical direction of the cavity. The elastic element is disposed between the telescopic sleeve and the sealing cap. A through hole is provided in the telescopic sleeve to form the third passage. The first unidirectional permeation membrane is disposed in the third passage to allow the conductive medium to flow unidirectionally along the cavity and the third passage.

[0006] Furthermore, the second sensing contact includes an annular sensing contact and a slow-release probe. The slow-release probe is fixed at the bottom of the telescopic sleeve. The annular sensing contact has a through hole through which the conductive medium flows. The slow-release probe is disposed below the annular sensing contact and clamps and fixes the annular sensing contact between the telescopic sleeve and the slow-release probe.

[0007] Furthermore, the outer casing includes a flexible support array and a guide sleeve. A through hole arranged vertically inside the guide sleeve forms the cavity. A plurality of guide holes connected to the cavity are arranged circumferentially on the guide sleeve. The outer periphery of the guide sleeve is provided with the flexible support array including a plurality of flexible supports. A channel for the wire of the first sensing contact and the conductive medium to pass through is provided inside the flexible support. The first sensing contact is positioned at one end of the flexible support. The other end of the flexible support is connected to the guide sleeve and communicates with the cavity through the guide hole.

[0008] Furthermore, a second unidirectional permeable membrane is provided at the port where the flexible support is connected to the guide sleeve, allowing the conductive medium to flow unidirectionally along the cavity and the channel.

[0009] Furthermore, the flexible support array is provided with an annular groove, and the second unidirectional permeation membrane is an annular permeation membrane, which is fixed in the annular groove by an annular retaining ring.

[0010] Furthermore, a guide is provided at the sliding contact surface of the telescopic sleeve and the guide sleeve, and a sealing element is also provided between the telescopic sleeve and the guide sleeve at the top of the telescopic sleeve.

[0011] Furthermore, the sealing cap is provided with a liquid injection through hole arranged vertically for the conductive medium to flow through, a one-way valve is provided in the liquid injection through hole, and a sealing element is provided between the sealing cap and the outer shell.

[0012] Furthermore, a quick-connect fitting for connecting to an external injection device is provided at the injection through-hole.

[0013] Furthermore, the sealing cap is also provided with a manual injection hole arranged in a vertical direction, and the manual injection hole is provided with a plug that can be detachably installed.

[0014] Furthermore, the first sensing contact and the second sensing contact can be stimulation electrodes and / or acquisition electrodes.

[0015] The dual-channel claw-type EEG electrode of the present invention includes a shell, an infusion mechanism, a first sensing contact and a second sensing contact. The second sensing contact moves under the action of external force, causing the infusion mechanism to compress the volume of the cavity, thereby driving the power supply medium to be applied between the first sensing contact and the scalp through the second channel, and between the second sensing contact and the scalp through the third channel, so as to realize the dual-channel function of acquisition and stimulation.

[0016] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this disclosure. Attached Figure Description

[0017] Figure 1 , Figure 2 This is a cross-sectional schematic diagram of a dual-channel claw-type EEG electrode according to an embodiment of the present invention.

[0018] Figure 3 This is a cross-sectional schematic diagram of the shell of a dual-channel claw-type EEG electrode according to an embodiment of the present invention;

[0019] Figure 4 This is a cross-sectional schematic diagram of a flexible support array according to an embodiment of the present invention;

[0020] Figure 5 This is a cross-sectional schematic diagram of a guide sleeve according to an embodiment of the present invention;

[0021] Figure 6 This is a schematic diagram showing the connection between the infusion mechanism and the second sensing contact according to an embodiment of the present invention;

[0022] Figure 7 This is a schematic diagram of a ring retainer according to an embodiment of the present invention;

[0023] Figure 8 This is a schematic diagram of an annular permeation membrane according to an embodiment of the present invention;

[0024] Figure 9 This is a schematic diagram of the assembly of an annular permeation membrane and an annular retaining ring according to an embodiment of the present invention;

[0025] Figure 10 This is a schematic diagram of a sealing cap according to an embodiment of the present invention;

[0026] Figure 11 This is a schematic diagram of an annular sensing contact and a spherical sensing contact according to an embodiment of the present invention. Detailed Implementation

[0027] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided to make this disclosure more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted.

[0028] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced with one or more of the specific details omitted, or other means may be employed. In other instances, well-known structures, methods, apparatuses, implementations, materials, or operations are not shown or described in detail to avoid obscuring various aspects of this disclosure.

[0029] like Figure 1 and Figure 2 As shown, the dual-channel claw-type EEG electrode of the present invention includes a shell 1, an infusion mechanism 2, a first sensing contact 3, and a second sensing contact 4. The shell 1 is covered with a sealing cover 5, and the sealing cover 5 is provided with a first channel for unidirectional input of conductive medium. The shell 1 is provided with a cavity 11 for the conductive medium to stagnate. Multiple first sensing contacts 3 are arranged circumferentially on the shell 1, and the infusion mechanism 2 is arranged at the bottom of the shell 1. The second sensing contact 4 is fixed on the infusion mechanism 2. The first sensing contact 3 is connected to the cavity 11 through a second channel provided on the shell 1, and the second sensing contact 4 is connected to the cavity 11 through a third channel provided on the infusion mechanism 2. The infusion mechanism 2 can move vertically up and down in the shell 1. The movement of the second sensing contact 4 under the action of external force causes the infusion mechanism 2 to compress the volume of the cavity 11, thereby driving the power supply medium to be applied between the first sensing contact 3 and the scalp through the second channel, and between the second sensing contact 4 and the scalp through the third channel.

[0030] In one embodiment of the present invention, such as Figure 6As shown, the infusion mechanism 2 includes a telescopic sleeve 21, an elastic element 22, and a first unidirectional permeable membrane 23. The telescopic sleeve 21 is slidably disposed within the outer shell 1 and can move up and down along the vertical direction of the cavity 11. The elastic element 22 is disposed between the telescopic sleeve 21 and the sealing cap 5. A through hole 211 is provided in the telescopic sleeve 21 to form the third passage. The first unidirectional permeable membrane 23 is disposed in the third passage to allow the conductive medium to flow unidirectionally along the cavity 11 and the third passage. The elastic element 22 can be a spring. When the second sensing contact 4 contacts the scalp, an upward pushing force is applied to the second sensing contact 4, which drives the telescopic sleeve 21 to move upward and compresses the spring to generate a downward restoring force. Under the action of the spring's restoring force, the second sensing contact 4 maintains close and uniform contact with the scalp, improving the accuracy of the second sensing contact in collecting EEG signals. The first one-way permeation membrane 23 is fixed by a retainer 24 and a retaining ring 25. The retainer 24 is a cylinder with a stepped through hole inside, and the retaining ring 25 is an annular cylinder. The retaining ring 25 is press-fitted to the retainer 24. The first one-way permeation membrane 23 is placed at the bottom of the large hole inside the retainer 24 and is confined between the retaining ring 25 and the retainer 24. The first one-way permeation membrane 23, the retainer 24, and the retaining ring 25 are placed in the one-way membrane cavity of the stepped through hole of the telescopic sleeve 21 and are press-fitted to the inner wall of the telescopic sleeve 21, allowing it to move up and down with the infusion mechanism 2 as a whole.

[0031] In one embodiment of the present invention, the second sensing contact 4 includes an annular sensing contact 41 and a slow-release probe 42. The slow-release probe 42 is fixedly disposed at the bottom of the telescopic sleeve 21. The annular sensing contact 41 has a through hole 411 through which the conductive medium flows. The slow-release probe 42 is disposed below the annular sensing contact 41 and clamps and fixes the annular sensing contact 41 between the telescopic sleeve 21 and the slow-release probe 42. An annular groove for fixing a horn pad 43 is provided on the outer periphery of the telescopic sleeve 21. The horn pad 43 is installed in the annular groove and wraps and fixes the slow-release probe 42 to the bottom of the telescopic sleeve 21. The slow-release probe 42 has a groove in the middle. The annular sensing contact 41 and the bottom of the telescopic sleeve 21 are accommodated in the groove, and the annular sensing contact 41 is clamped and fixed between the telescopic sleeve 21 and the slow-release probe 42. A wire 412 is connected to one side of the annular sensor 41 to apply a stimulation signal or an EEG signal to the annular sensor 41. The sides of the slow-release probe 42 and the speaker pad 43 have lead holes to lead the wire 412 outward. The conductive liquid flows downward through the through hole above the telescopic sleeve 21, and flows into the slow-release probe 42 through the first one-way permeable membrane 23 and the through hole 411 of the annular sensor 41. The slow-release probe 42 can be a sponge, and the conductive liquid can slowly fall onto the scalp in contact with the slow-release probe 42 through the sponge.

[0032] In one embodiment of the present invention, such as Figure 3As shown, the outer casing 1 includes a flexible support array 12 and a guide sleeve 13. A through hole arranged vertically within the guide sleeve 13 forms the cavity 11. Multiple flow guide holes 131 connected to the cavity 11 are arranged circumferentially on the guide sleeve 13. The flexible support array 12, including multiple flexible supports, is arranged on the outer periphery of the guide sleeve 13. Channels 121 are provided within each flexible support for the wire of the first sensing contact 3 and the conductive medium to pass through. The first sensing contact 3 is positioned at one end of each flexible support, and the other end of each flexible support is connected to the guide sleeve 13 and communicates with the cavity 11 through the flow guide holes 131. A boss 132 for securing the flexible support array 12 is arranged circumferentially on the guide sleeve 13. An annular groove 133 for mounting the guide sleeve 6 is located on the inner bottom side of the guide sleeve 13. The number of flow guide holes 131 corresponds to the number of flexible supports in the flexible support array 12, allowing conductive liquid to flow through the flow guide holes 131 to each flexible support. The internal channel 121 of the flexible support leg is filled with a liquid-filling material 122. This liquid-filling material primarily absorbs, stores, and transports liquids, and includes, but is not limited to, sponges, fibers, and porous materials. The wire 31 of the first sensing contact 3 is wrapped in the liquid-filling material 122 for protection while simultaneously allowing it to be electrically connected to the conductive liquid to transmit signals. The flexible support leg has a claw-shaped structure, which, upon contact with the scalp, can bend and deform according to the head's contour, ensuring that the spherical sensing contact at one end of the flexible support leg makes tight and uniform contact with the scalp.

[0033] In one embodiment of the present invention, such as Figure 7-9 As shown, a second unidirectional permeable membrane 123 is provided at the port where the flexible support connects to the guide sleeve 13, allowing the conductive medium to flow unidirectionally along the cavity 11 and the channel 121. An annular groove is provided within the flexible support array 12. The second unidirectional permeable membrane 123 is an annular permeable membrane, which is fixed in the annular groove by an annular retaining ring 124. The annular retaining ring 124 has multiple through holes 125 corresponding to the flow guide hole 131 on its circumference. A retaining groove 126 is also provided on the annular retaining ring 124, through which the annular permeable membrane is embedded to the annular retaining ring 124 to ensure that the annular permeable membrane can be firmly fixed outside the flow guide hole 131.

[0034] In one embodiment of the present invention, such as Figure 10As shown, the sealing cover 5 is provided with a vertically oriented injection port for the conductive medium to flow through. A one-way valve 51 is installed inside the injection port. A sealing element 52 is provided between the sealing cover 5 and the outer shell 1. A quick-connect connector 53 is provided at the injection port for connection to an external injection device. An L-shaped through-hole is provided inside the quick-connect connector 53. The horizontal section of the L-shaped through-hole is connected to the external conductive liquid injection device through a conduit 54, and the vertical section of the L-shaped through-hole is connected to the input end of the one-way valve 51. The conductive liquid flows through the conduit 54 to the one-way valve 51 and is automatically injected into the cavity 11 of the outer shell 1 from the output end of the one-way valve 51. The sealing cover 5 is also provided with a vertically oriented manual injection port, which is equipped with a detachable plug 55. The sealing cover 5 has a first step structure 511, a second step structure 512, and a third step structure 513. An upper limit groove 521 is provided between the first step structure 511 and the second step structure 512 to engage and position the upper part of the elastic element 22. A lower limit groove 522 is provided on the top of the telescopic sleeve 21 to engage and position the lower part of the elastic element 22. A sealing groove 523 is provided between the second step structure 512 and the third step structure 513, and the sealing element 52 is installed in the sealing groove 523.

[0035] In one embodiment of the present invention, such as Figure 11 As shown, the first sensing contact 3 and the second sensing contact 4 can serve as stimulation electrodes and / or acquisition electrodes. The cylindrical boss of the spherical sensing contact 32 of the first sensing contact 3 is placed in the through hole inside the flexible support leg of the claw-type housing. The spherical sensing contact 32 is initially fixed by the elastic contraction force of the flexible support leg, supplemented by adhesive bonding. Each flexible support leg has a corresponding spherical sensing contact 32 fixed at its end. The wires 31 of all spherical sensing contacts 32 are led out through the corresponding through hole inside the flexible support leg, converge and weld together in the annular groove on the inner surface of the guide sleeve 13, and finally the signal is transmitted outward through a wire through the wire hole between the walls of the claw-type housing. The surface of the spherical sensing contact 32 has multiple liquid guiding holes, and the conductive liquid can slowly seep out through the internal channels of the flexible support leg.

[0036] In one embodiment of the present invention, guide sleeves 6 and 7 are further provided at the sliding contact surface between the telescopic sleeve 21 and the guide sleeve 13 to guide the telescopic sleeve 21 as it moves up and down in the guide sleeve 13 and prevent wear between the telescopic sleeve 21 and the guide sleeve 13. In addition, a sealing element 8 is provided between the telescopic sleeve 21 and the guide sleeve 13 at the top of the telescopic sleeve 21 to prevent the conductive liquid in the cavity 11 from leaking between the telescopic sleeve 21 and the guide sleeve 13.

[0037] In summary, this invention offers two methods for adding conductive fluid: manual injection with a syringe or simultaneous and rapid supply of conductive fluid to multi-channel EEG electrodes via an inlet catheter. The first sensing contact employs a flexible claw structure, while the second sensing contact in the center provides elastic support. This combination effectively overcomes hair obstruction, ensuring conformal, stable, and comfortable contact with the scalp's curvature. It features two signal circuits—the first and second sensing contacts—allowing for both simultaneous signal acquisition and bidirectional signal transmission through separate acquisition and stimulation pathways. When the EEG cap is worn, the conductive fluid is rapidly released, quickly reducing the contact impedance between the EEG electrodes and the scalp. Once stable, the supply and release rate of the conductive fluid balances with the amount of evaporation, enabling long-term, low-impedance acquisition of EEG signals.

[0038] To enable those skilled in the art to better understand the present invention, its working principle is explained in detail below, taking into account the structure of the aforementioned dual-channel claw-type EEG electrode:

[0039] The dual-channel claw-type EEG electrode of the present invention has an annular groove on the outer surface of the large circle of the claw-type shell, which is fixed in the electrode mounting holes at various points on the EEG cap. After the EEG cap is combined with multiple EEG electrodes, it forms an EEG cap that can collect EEG signals.

[0040] When the subject wears the EEG cap, the spherical sensing contacts of the EEG electrodes penetrate the hair barrier and make contact with the scalp. As the contact force increases, the flexible claw-shaped support array connected to the spherical sensing contacts bends and deforms. Simultaneously, the central elastic contact compresses the spring and moves upward, thus forming a state where the flexible claw-shaped supports and the central elastic support are in contact with the scalp simultaneously. The flexibility of the claw-shaped support and the elasticity of the spring compressed by the central elastic contact work together to improve the stability, flexibility, and comfort of the EEG electrodes in contact with the scalp. As the central elastic contact contracts and moves, it compresses the liquid in the reservoir. The amount of conductive liquid transported from the reservoir through the cylindrical one-way permeation component and the annular one-way permeation membrane increases, and it is rapidly released to the contact surface with the scalp through the slow-release probe and the spherical sensing contacts, quickly reducing the interfacial resistance.

[0041] Once the EEG cap is worn and adjusted stably, the contact pressure between the EEG electrodes and the scalp stabilizes, and the spring compression stroke remains relatively stable. When the fluid pressure within the infusion chamber returns to a relatively stable state, the amount of conductive fluid transported outward from the reservoir through the cylindrical one-way permeation component and the annular one-way permeation membrane decreases. The conductive fluid is slowly transported through the cylindrical one-way permeation component to the sustained-release probe and then slowly released onto the contact surface between the sustained-release probe and the scalp. Simultaneously, the conductive fluid is slowly transported through another fluid flow path, through the annular one-way permeation membrane and the reservoir filling material, to the spherical sensing contact and then slowly released onto the contact surface between the spherical sensing contact and the scalp. By releasing conductive fluid onto the sustained-release probe / scalp contact surface and the spherical sensing contact / scalp contact surface, the high-impedance stratum corneum of the scalp is wetted and connected, thereby reducing interfacial impedance and opening the EEG signal transmission pathway. When the conductive fluid released onto the EEG electrode-scalp surface reaches equilibrium with the evaporated conductive fluid, a stable interfacial impedance balance can be maintained for a long time, achieving long-term, low-impedance acquisition of EEG signals.

[0042] During an EEG test, conductive fluid can be manually added. Remove the plugs from the EEG electrodes and use a syringe to inject conductive fluid into the reservoir inside the electrodes through the manual injection hole in the screw cap. When the conductive fluid in the reservoir has evaporated completely after passing through the slow-release probe and the spherical sensing contact, the conductive fluid can be replenished by manually adding more conductive fluid.

[0043] For long-term monitoring of EEG signals, conductive fluid can be automatically added via a catheter. The conductive fluid is automatically delivered to the reservoir via the catheter, L-shaped connector, and one-way valve, and then through two pathways to the slow-release probe and the spherical sensing contact. When the reservoir is full, excess conductive fluid is discharged into the external fluid system through the manual injection port on the screw cap. The conductive fluid content in the reservoir can be inferred by real-time monitoring of the interfacial impedance between the electrode and the scalp. When the conductive fluid is insufficient, it is automatically added to the reservoir via the external fluid system. By combining real-time impedance monitoring and automatic fluid replenishment, a low interfacial impedance state can be maintained for extended periods, enabling long-term acquisition of EEG signals.

[0044] The dual-channel claw-type EEG electrode can function as a dry electrode or a semi-dry electrode after the injection of conductive fluid. When no conductive fluid is injected, the EEG signal is sensed by the spherical inductive contact and transmitted to the amplification and processing system at the back end.

[0045] The dual-channel claw-type EEG electrode has two signal circuits: a central elastic contact and a claw-type end spherical sensing contact. It can simultaneously acquire EEG signals in separate channels, or it can acquire and stimulate signals in a two-way bidirectional transmission, with one channel for acquisition and the other for stimulation.

[0046] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0047] The embodiments described above are merely examples of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application.

Claims

1. A dual-channel claw-type EEG electrode, characterized in that, The device includes a housing, an infusion mechanism, a first sensing contact, and a second sensing contact. The housing is covered with a sealing cap, which has a first channel for unidirectional input of a conductive medium. The housing contains a cavity for the conductive medium to stagnate. Multiple first sensing contacts are arranged circumferentially around the housing, and the infusion mechanism is located at the bottom of the housing. The second sensing contacts are fixed to the infusion mechanism. The first sensing contacts communicate with the cavity through a second channel on the housing, and the second sensing contacts communicate with the cavity through a third channel on the infusion mechanism. When the second sensing contacts move under external force, they cause the infusion mechanism to compress the cavity volume, thereby driving the conductive medium to be applied between the first sensing contact and the scalp via the second channel, and between the second sensing contact and the scalp via the third channel. The two signal circuits can simultaneously acquire signals and also acquire and stimulate bidirectional transmission signals. The infusion mechanism includes a telescopic sleeve, an elastic element, and a first unidirectional permeation membrane. The telescopic sleeve is slidably disposed within the outer shell and can move up and down along the vertical direction of the cavity. The elastic element is disposed between the telescopic sleeve and the sealing cap. A through hole is provided in the telescopic sleeve to form the third passage. The first unidirectional permeation membrane, which allows the conductive medium to flow unidirectionally along the cavity and the third passage, is disposed in the third passage. The outer shell includes a flexible support array and a guide sleeve. A through hole is provided in the guide sleeve along the vertical direction to form the cavity. Multiple flow guide holes connected to the cavity are provided in the circumferential direction of the guide sleeve. The outer periphery of the guide sleeve is provided with the flexible support array including multiple flexible supports. A channel for the wire of the first sensing contact and the conductive medium to pass through are provided in the flexible supports. The first sensing contact is positioned at one end of the flexible support. The other end of the flexible support is connected to the guide sleeve and communicates with the cavity through the flow guide hole.

2. The dual-channel claw-type EEG electrode as described in claim 1, characterized in that, The second sensing contact includes an annular sensing contact and a slow-release probe. The slow-release probe is fixed at the bottom of the telescopic sleeve. The annular sensing contact has a through hole through which the conductive medium flows. The slow-release probe is disposed below the annular sensing contact and clamps and fixes the annular sensing contact between the telescopic sleeve and the slow-release probe.

3. The dual-channel claw-type EEG electrode as described in claim 1, characterized in that, A second unidirectional permeable membrane is provided at the port where the flexible support is connected to the guide sleeve, allowing the conductive medium to flow unidirectionally along the cavity and the channel.

4. The dual-channel claw-type EEG electrode as described in claim 3, characterized in that, The flexible support array is provided with an annular groove, and the second unidirectional permeation membrane is an annular permeation membrane, which is fixed in the annular groove by an annular retaining ring.

5. The dual-channel claw-type EEG electrode as described in claim 1, characterized in that, A guide is provided at the sliding contact surface of the telescopic sleeve and the guide sleeve, and a sealing element is also provided between the telescopic sleeve and the guide sleeve at the top of the telescopic sleeve.

6. The dual-channel claw-type EEG electrode as described in claim 1, characterized in that, The sealing cap is provided with a liquid injection through hole arranged vertically for the conductive medium to flow through, and a one-way valve is provided in the liquid injection through hole. A sealing element is provided between the sealing cap and the outer shell.

7. The dual-channel claw-type EEG electrode as described in claim 6, characterized in that, The injection port is provided with a quick-connect connector for connecting to an external injection device; the sealing cap is also provided with a manual injection hole arranged vertically, and the manual injection hole is provided with a detachable plug.

8. The dual-channel claw-type EEG electrode as described in claim 1, characterized in that, The first sensing contact and the second sensing contact can be stimulation electrodes and / or acquisition electrodes.

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