A front-end probe for electroencephalography electrodes and an electroencephalography electrode

Abstract

This application discloses a front-end probe and EEG electrodes for use with EEG electrodes, belonging to the field of EEG technology. The front-end probe includes a blocking layer, an absorbent layer, a conductive layer, and an interface layer. The blocking layer forms a receiving cavity, in which the absorbent layer, conductive layer, and interface layer are all disposed. Along the direction from the outer wall to the inner wall of the blocking layer, the absorbent layer, conductive layer, and interface layer are arranged sequentially. The absorbent layer covers at least a portion of the conductive layer, and the conductive layer covers at least a portion of the interface layer. The interface layer is used to connect an elastic support rod of the EEG electrode. Along a first direction, the blocking layer has a top and a bottom opposite each other. The top has a through hole for the elastic support rod to pass through, and the bottom is a closed structure. The side of the blocking layer has an opening opposite to at least a portion of the absorbent layer. The side of the blocking layer is the portion between the top and bottom of the blocking layer.

Description

Technical Field

[0001] This application relates to the field of electroencephalography (EEG) technology, and more particularly to a front-end probe and EEG electrodes for use as EEG electrodes. Background Technology

[0002] In brain-computer interface (BCI) systems, reliable acquisition of electroencephalography (EEG) signals is fundamental to achieving high-precision human-computer interaction. Among these parameters, the contact impedance between the electrodes and the scalp is one of the key parameters determining signal quality. A low and stable scalp impedance (typically required to be below 10 kΩ) can effectively reduce motion artifacts, power line interference, and thermal noise, thereby ensuring the signal-to-noise ratio of the EEG signal.

[0003] In related technologies, saline electrodes (or wet electrodes) are widely used in portable or rapidly deployable EEG acquisition or measurement scenarios due to their ease of operation and low cost. Saline electrodes typically employ porous sponges or fiber materials to absorb conductive solutions (such as potassium chloride or sodium chloride solutions), achieving ion conduction between the scalp and the metal electrode through a salt bridge effect. Because the conductive solution can fill the microstructure of the stratum corneum, it can significantly reduce the skin-electrode interface impedance, resulting in EEG signals with a higher signal-to-noise ratio than dry electrodes.

[0004] However, in related technologies, saline electrodes initially contain a large amount of conductive solution, typically greater than 1 mL, which easily leads to leakage during use. Specifically, existing saline electrodes usually have a bottom opening, and the conductive solution tends to leak out due to gravity during water absorption and use; furthermore, the bottom opening area is large, typically greater than 100 mm². 2 Hair is often present between the sponge and the scalp, and the siphon effect of the hair can easily cause the conductive solution to leak out. Furthermore, the sponge is easily compressed over a large area during wear or use, which can also lead to leakage of the conductive solution. In other words, after the saline electrode comes into contact with the scalp, the conductive solution easily leaks out, causing unstable contact impedance between the scalp and the saline electrode, with the impedance value rising rapidly. This shortens the effective usage time of the saline electrode, typically less than 40 minutes. Simultaneously, the leaking conductive solution may increase the risk of short circuits between the saline electrodes, which is detrimental to long-term, stable, and reliable EEG signal acquisition or measurement. Summary of the Invention

[0005] This application aims to provide a front-end probe and EEG electrode for use with EEG electrodes, at least to solve the problem that when saline electrodes come into contact with the skin of the human head, the conductive solution tends to leak out, which leads to unstable contact impedance between the skin and the saline electrode and a rapid increase in impedance value, thereby shortening the effective use time of the saline electrode; at the same time, the leaked conductive solution may also increase the risk of short circuits between saline electrodes, which is not conducive to long-term, stable and reliable acquisition or measurement of EEG signals.

[0006] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, embodiments of this application provide a front-end probe for electroencephalogram (EEG) electrodes, the front-end probe comprising a blocking layer, a liquid-absorbing layer, a conductive layer, and an interface layer; The barrier layer forms a receiving cavity, and the liquid-absorbing layer, the conductive layer, and the interface layer are all disposed in the receiving cavity. Along the direction from the outer wall to the inner wall of the barrier layer, the liquid-absorbing layer, the conductive layer, and the interface layer are arranged in sequence. The liquid-absorbing layer covers at least part of the conductive layer, and the conductive layer covers at least part of the interface layer. The interface layer is used to connect the elastic support rod of the EEG electrode. Along a first direction, the barrier layer has an opposing top and bottom, the top having a through hole for the elastic support rod to pass through, the bottom being a closed structure, and the side of the barrier layer having an opening opposite at least a portion of the liquid-absorbing layer, the side of the barrier layer being the portion between the top and bottom of the barrier layer.

[0007] Optionally, the bottom of the barrier layer is configured as a pointed arc, a rounded arc, or a wedge-shaped structure.

[0008] Optionally, the top of the barrier layer is configured as a pointed arc, a rounded arc, or a wedge-shaped structure.

[0009] Optionally, the liquid-absorbing layer has a porous structure.

[0010] Optionally, the conductive layer includes at least one of a conductive metal and a conductive non-metal.

[0011] Optionally, the interface layer is provided with a connecting part for connecting with the elastic support rod.

[0012] In a second aspect, embodiments of this application provide an electroencephalogram (EEG) electrode, which includes an electrode base, at least one elastic support rod, and at least one front probe as described in any of the first aspects above; The first end of the elastic support rod is fixed to the electrode base, and the second end of the elastic support rod passes through the through hole and is connected to the interface layer.

[0013] Optionally, when the elastic support rod is not deformed, there is an angle between the central axis of the elastic support rod and the center line of the electrode base.

[0014] Optionally, when the front probe contacts the scalp surface, if the elastic support rod is not deformed, the angle between the centerline of the front probe and the tangent at the contact point between the scalp surface and the front probe is a first angle; if the elastic support rod is deformed, the angle between the centerline of the front probe and the tangent at the contact point between the scalp surface and the front probe is a second angle, and the second angle is smaller than the first angle.

[0015] Optionally, the first angle is greater than or equal to 60° and less than or equal to 85°, and the second angle is greater than 0° and less than or equal to 45°.

[0016] In this embodiment, by providing an opening on the side of the barrier layer and having a closed structure at the bottom, when the front probe contacts the scalp, it not only ensures contact between the scalp and the absorbent layer, achieving a conductive connection between them and ensuring the front probe can acquire or measure EEG signals, but also reduces the large-area exposure of the absorbent layer. This helps reduce the risk of excessive loss of conductive solution due to the siphon effect of hair, thus avoiding the problem of a rapid increase in contact impedance between the front probe and the scalp, which is detrimental to long-term EEG signal acquisition or measurement. In other words, this embodiment effectively reduces the probability of conductive solution leakage, lowers the risk of short circuits between adjacent front probes due to conductive solution outflow, thereby improving the stability of EEG signal acquisition and facilitating long-term EEG signal acquisition or measurement. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram illustrating a barrier layer provided in an embodiment of this application; Figure 2 This is a cross-sectional view of a front-end probe provided in an embodiment of this application; Figure 3 This diagram illustrates an electroencephalogram (EEG) electrode provided in an embodiment of this application. Figure 4 This is a schematic diagram showing the elastic support rod in an EEG electrode provided in an embodiment of this application when it is not deformed. Figure 5 This is a schematic diagram showing the deformation of an elastic support rod in an EEG electrode according to an embodiment of this application. Figure 6 This is a schematic diagram showing the front probe of an EEG electrode provided in an embodiment of this application being attached to the human scalp.

[0018] Figure label: 10: Barrier layer; 11: Top; 12: Bottom; 101: Receiving cavity; 102: Opening; 111: Through hole; 20: Liquid absorption layer; 30: Conductive layer; 40: Interface layer; 100: Electrode base; 200: Elastic support rod; α: First angle; β: Second angle; X: First direction. Detailed Implementation

[0019] To facilitate a clear description of the technical solutions in the embodiments of the present invention, the terms "first" and "second" are used to distinguish identical or similar items with essentially the same function and effect. For example, the first threshold and the second threshold are merely used to distinguish different thresholds and do not limit their order. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that the terms "first" and "second" are not necessarily different.

[0020] It should be noted that in this invention, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0021] In this invention, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one" or similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, "at least one of a, b, or c" can represent: a, b, c, a combination of a and b, a combination of a and c, a combination of b and c, or a, b, and c, where a, b, and c can be single or multiple.

[0022] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0023] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0024] This application provides a front-end probe for electroencephalogram (EEG) electrodes, such as... Figure 1 and Figure 2 As shown, the front-end probe includes a blocking layer 10, a liquid absorption layer 20, a conductive layer 30, and an interface layer 40.

[0025] The barrier layer 10 forms a receiving cavity 101, in which the absorbent layer 20, the conductive layer 30, and the interface layer 40 are all disposed. Along the direction from the outer wall to the inner wall of the barrier layer 10, the absorbent layer 20, the conductive layer 30, and the interface layer 40 are arranged sequentially. The absorbent layer 20 covers at least a portion of the conductive layer 30, and the conductive layer 30 covers at least a portion of the interface layer 40. The interface layer 40 is used to connect the elastic support rod 200 of the EEG electrode. Along the first direction X, the barrier layer 10 has a top 11 and a bottom 12. The top 11 is provided with a through hole 111 for the elastic support rod 200 to pass through. The bottom 12 is a closed structure. The side of the barrier layer 10 is provided with an opening 102, which is at least partially opposite to the absorbent layer 20. The side of the barrier layer 10 is the part between the top 11 and the bottom 12 of the barrier layer 10.

[0026] It should be noted that when the front-end probe is applied to the EEG electrodes to collect or measure the body's electroencephalogram (EEG) signals, the opening 102 faces the scalp and gradually closes to the scalp, ensuring that the conductive solution does not easily leak out. For example, as... Figure 6 As shown, the front probe fits against the human scalp, and the opening 102 is completely sealed by the scalp.

[0027] In this embodiment, since the absorbent layer 20, the conductive layer 30, and the interface layer 40 are all disposed in the receiving cavity 101, and are arranged sequentially along the direction from the outer wall to the inner wall of the barrier layer 10, the absorbent layer 20 covers at least part of the conductive layer 30, and the conductive layer 30 covers at least part of the interface layer 40, when the front probe is applied to the EEG electrode, the elastic support rod 200 of the EEG electrode can be connected to the interface layer 40, so that the absorbent layer 20 can transmit the EEG signal to the conductive layer 30, the conductive layer 30 can transmit the signal to the interface layer 40, and the interface layer 40 can transmit the signal to the elastic support rod 200. That is, the interface layer 40 can transmit the EEG signal collected by the front probe to the outside. Along the first direction X, the barrier layer 10 has a top 11 and a bottom 12. The top 11 has a through hole 111, and the bottom 12 is a closed structure. The side of the barrier layer 10 has an opening 102, which is at least partially opposite to the absorbent layer 20. Therefore, when the front probe is applied to the EEG electrode, the elastic support rod 200 can pass through the through hole 111 of the top 11 and connect to the interface layer 40. Since the bottom 12 is a closed structure, the top 11 and bottom 12 of the barrier layer 10 can limit the absorbent layer 20 to a certain extent, preventing the absorbent layer 20 from detaching from the barrier layer 10. Furthermore, the structure of the barrier layer 10 can block the conductive solution adsorbed by the absorbent layer 20 to a certain extent and limit the diffusion range of the conductive solution in the absorbent layer 20. To reduce the outflow of conductive solution, the barrier layer 10 has an opening 102 on its side, which reduces the risk of conductive solution flowing out from the bottom 12 under gravity. When the front probe contacts the scalp, the opening 102 faces the scalp, so the opening 102 is completely sealed by the scalp, ensuring that the absorbent layer 20 is conductive to the scalp while inhibiting the outflow of conductive solution. The opening 102 on the side of the barrier layer 10 also allows the absorbent layer 20 to contact the outside. That is, when the front probe contacts the scalp, it ensures that the absorbent layer 20 can contact the scalp, realizing the conductive connection between the absorbent layer 20 and the scalp. At the same time, it reduces the large-area exposure of the absorbent layer 20, and the small size of the side opening 102 reduces the risk of conductive solution loss caused by the siphon effect of hair.

[0028] In other words, in this embodiment, by providing an opening 102 on the side of the blocking layer 10 and making the bottom 12 of the blocking layer 10 a closed structure, when the front probe contacts the scalp of the human body, it not only ensures that the scalp is in contact with the absorbent layer 20, achieving a conductive connection between the scalp and the absorbent layer 20, and ensuring that the front probe can collect or measure EEG signals, but also reduces the large-area exposure of the absorbent layer 20, which helps to reduce the risk of excessive loss of conductive solution due to the siphon effect of hair. This avoids the problem of a rapid increase in contact impedance between the front probe and the scalp, which is detrimental to long-term EEG signal collection or measurement. In other words, in this embodiment, the probability of easy loss of conductive solution can be effectively reduced, and the risk of short circuits between adjacent front probes due to the outflow of conductive solution can be reduced, thereby improving the stability of EEG signal collection and facilitating long-term EEG signal collection or measurement.

[0029] The front-end probe provided in this application embodiment is installed after the EEG electrode. Experimental verification shows that the effective usage time of the EEG electrode composed of the front-end probe is greater than 2 hours, which far exceeds the effective usage time of the EEG electrode in related technologies.

[0030] In addition, in this embodiment, the absorbent layer 20 stores a small amount of conductive solution, only 0.025 mL, which is much smaller than the amount of conductive solution adsorbed by the saline electrode in the related technology. This can avoid the problem of easy loss of conductive solution while ensuring that the front probe is in contact with the scalp and that there is a conductive connection between the absorbent layer 20 and the scalp.

[0031] It should be noted that in this embodiment, the barrier layer 10 can be formed of plastic. Of course, the barrier layer 10 can also be formed of other materials, such as epoxy board or ceramic. This embodiment does not limit the specific materials used in this application.

[0032] It should also be noted that, in this embodiment, the absorbent layer 20 may cover the entire conductive layer 30, or it may only cover a portion of the conductive layer 30. This embodiment does not limit the scope of this application. Similarly, the conductive layer 30 may cover the entire interface layer 40, or it may only cover a portion of the interface layer 40. This embodiment does not limit the scope of this application.

[0033] In addition, in this embodiment, the opening 102 may be positioned opposite to the absorbent layer 20, meaning that the interior of the opening 102 corresponds entirely to the absorbent layer 20. This ensures that when the probe contacts the scalp, the absorbent layer 20 is in contact with the scalp at the opening 102, thus creating a conductive connection between the absorbent layer 20 and the scalp. Alternatively, only a portion of the absorbent layer 20 may be positioned opposite the opening 102. This embodiment does not limit the specific placement of the absorbent layer 20.

[0034] Furthermore, in this embodiment, the specific shape of the through hole 111 in the top 11 of the barrier layer 10 can be set according to actual needs. For example, the through hole 111 can be circular, square, or hexagonal. This embodiment does not limit this. When the through hole 111 is circular, its diameter can be set according to actual needs. For example, the diameter can be 1mm or 2mm. This embodiment does not limit this either. It is only necessary to ensure that the elastic support rod 200 can pass through the through hole 111.

[0035] Furthermore, in this embodiment, the opening 102 can be rectangular. Of course, the opening 102 can also be other shapes, such as an ellipse or a parallelogram. The specific shape of the opening 102 is not limited in this embodiment. When the opening 102 is rectangular, its width is 3mm and its length is 5mm, meaning the area of ​​the opening 102 is only 15mm². 2 That is, the area of ​​opening 102 is smaller, which reduces the probability of conductive solution flowing out from opening 102.

[0036] In addition, in some embodiments, the bottom 12 of the blocking layer 10 is configured as a pointed arc, a rounded arc, or a wedge-shaped structure. With such a configuration, when the front probe contacts the scalp, the structure of the bottom 12 of the blocking layer 10 can facilitate the bottom 12 of the blocking layer 10 to push away the hair, reducing the risk of the blocking layer 10 being caught by the hair, which is beneficial for the front probe to fit the scalp and also facilitates the separation of the front probe from the scalp.

[0037] In some embodiments, the top 11 of the barrier layer 10 is configured as a pointed arc, a rounded arc, or a wedge-shaped structure. This configuration reduces the risk of the barrier layer 10 being caught by hair when the probe contacts the scalp. It also reduces the likelihood of hair entering the receiving cavity 101 from the top 11 during probe separation, preventing hair from trapping or tangling the probe and hindering scalp separation. In other words, by configuring the top 11 of the barrier layer 10 as a pointed arc, a rounded arc, or a wedge-shaped structure, separation of the probe from the scalp is facilitated.

[0038] In some embodiments, the absorbent layer 20 has a porous structure. This design facilitates the absorption of the conductive solution by the absorbent layer 20, allows the conductive solution to be retained in the absorbent layer 20, and enables it to be slowly released to the scalp surface through the opening 102 on the side of the barrier layer 10, thereby reducing contact resistance.

[0039] It should be noted that in this embodiment, the absorbent layer 20 can be made of sponge. Of course, the absorbent layer 20 can also be made of other materials, such as porous gel. This embodiment does not limit the specific materials used in this application.

[0040] In addition, in some embodiments, the conductive layer 30 includes at least one of a conductive metal and a conductive non-metal.

[0041] The conductive layer 30 may consist only of conductive metal, i.e., the conductive layer 30 is made only of conductive metal. Of course, the conductive layer 30 may also consist only of conductive non-metal, i.e., the conductive layer 30 is made only of conductive non-metal. Alternatively, the conductive layer 30 may include both conductive non-metal and conductive metal. In this case, the conductive metal can form one layer of structure, and the conductive non-metal can form another layer of structure, with the structure formed by the conductive metal and the structure formed by the conductive non-metal stacked and in contact.

[0042] It should be noted that conductive non-metals may include, but are not limited to, silicon carbide, conductive alumina ceramics, polyaniline, etc.

[0043] In some embodiments, the interface layer 40 is provided with a connecting portion (not shown in the figure) for connecting with the elastic support rod 200. By providing the connecting portion, when the front probe is applied to the EEG electrodes, after the elastic support rod 200 passes through the through hole 111 of the top 11 of the blocking layer 10, the elastic support rod 200 can be connected to the connecting portion, thereby facilitating the connection between the interface layer 40 and the elastic support rod 200.

[0044] It should be noted that the connecting part can be a connecting groove. In this case, the elastic support rod 200 passes through the through hole 111 and can be directly embedded in the connecting groove to achieve the connection between the elastic support rod 200 and the interface layer 40. The connecting part and the connecting groove can be interference-fitted; of course, the connecting part and the connecting groove can also be welded together. This embodiment of the application does not limit the specifics of this method.

[0045] Alternatively, in this embodiment, the interface layer 40 may not have a connecting part. In this case, after the elastic support rod 200 passes through the through hole 111, the interface layer 40 and the elastic support rod 200 can be directly connected by welding.

[0046] This application provides an electroencephalogram (EEG) electrode, such as... Figure 3 As shown, the EEG electrode includes an electrode base 100, at least one elastic support rod 200, and at least one front probe as described in any of the above embodiments; the first end of the elastic support rod 200 is fixed to the electrode base 100, and the second end of the elastic support rod 200 passes through the through hole 111 and is connected to the interface layer 40.

[0047] Since the first end of the elastic support rod 200 is fixed to the electrode base 100, and the second end of the elastic support rod 200 passes through the through hole 111 and is connected to the interface layer 40, the elastic support rod 200 can deform when collecting or measuring EEG signals through the EEG electrodes, thereby changing the angle between the front probe and the scalp surface, thus improving the reliability and stability of the contact between the front probe and the scalp. After the EEG signal is transmitted to the absorbent layer 20, the absorbent layer 20 can transmit the EEG signal to the conductive layer 30, the conductive layer 30 can transmit the EEG signal to the interface layer 40, the interface layer 40 can transmit the EEG signal to the elastic support rod 200, and the elastic support rod 200 can transmit the EEG signal to the electrode base 100, through which it can be transmitted outward.

[0048] It should be noted that the electrode base 100 can be made of a printed circuit board, with the first end of each elastic support rod 200 soldered to the printed circuit board, and the second end of each elastic support rod 200 passing through the through hole 111 of the top 11 of the barrier layer 10 and connected to the interface layer 40.

[0049] In addition, in this embodiment, the elastic support rod 200 can be a stainless steel wire with a diameter of 0.3 mm, one end of which is fixed to the electrode base 100, and the other end passes through the through hole 111 of the top 11 of the front probe and connects to the interface layer 40. Of course, the elastic support rod 200 can also be formed of copper wire or silver wire. The specific material of the elastic support rod 200 is not limited in this embodiment.

[0050] Additionally, in some embodiments, when the elastic support rod 200 is not deformed, there is an angle between the central axis of the elastic support rod 200 and the center line of the electrode base 100. With this arrangement, when using the EEG electrodes, once the front probe contacts the scalp, the angle between the central axis of the elastic support rod 200 and the center line of the electrode base 100 when the elastic support rod 200 is not deformed is equivalent to the elastic support rod 200 and the front probe being tilted relative to the electrode base 100. Thus, when the EEG electrodes are worn, the elastic support rod 200 will deform, and the angle between the central axis of the elastic support rod 200 and the center line of the electrode base 100 facilitates the contact between the front probe and the scalp when the elastic support rod 200 deforms, and ensures that the opening 102 faces the scalp.

[0051] In addition, in this embodiment of the application, when the elastic support rod 200 is not deformed, the opening 102 is located on the side of the blocking layer 10 away from the electrode base 100, so that when the EEG electrode is worn, the opening 102 faces the scalp of the human body, so that when the front probe is in contact with the scalp, the opening 102 can be completely closed by the scalp.

[0052] Additionally, in some embodiments, such as Figure 4 and Figure 5 As shown, when the front probe contacts the scalp surface, and the elastic support rod 200 is not deformed, the angle between the center line of the front probe and the tangent at the contact point of the scalp surface and the front probe is the first angle α; when the elastic support rod 200 is deformed, the angle between the center line of the front probe and the tangent at the contact point of the scalp surface and the front probe is the second angle β, and the second angle β is less than the first angle α.

[0053] With this setup, when collecting or measuring EEG signals through EEG electrodes, the elastic support rod 200 deforms, and the angle between the front probe and the scalp surface changes. This allows the front probe to conform to the curvature of the scalp surface and form a relatively stable contact with it. At the same time, it ensures that the opening 102 on the side of the blocking layer 10 always faces the scalp, enabling the release of conductive solution and the collection and measurement of EEG signals.

[0054] In some embodiments, the first angle α ranges from 60° to 85°, and the second angle β ranges from 0° to 45°. This configuration allows the front probe to move well along the scalp surface when the elastic support rod 200 deforms, ensuring that the opening 102 on the side of the blocking layer 10 always faces the scalp surface.

[0055] It should be noted that the first angle α can be any value greater than or equal to 60° and less than or equal to 85°. For example, the first angle α is 85°, 80°, 75°, 65°, or 60°. Similarly, the second angle β can be any value greater than 0° and less than or equal to 45°. For example, the second angle β is 10°, 15°, 20°, 30°, or 45°.

[0056] For example, when the front probe contacts the scalp surface, the first angle α is 80° when the elastic support rod 200 is not deformed. When the elastic support rod 200 is bent and deformed under pressure, the front probe gradually deflects to become parallel to the scalp surface. At this time, the included angle decreases to 10°, that is, the second angle β is 10°.

[0057] In addition, in this embodiment, when installing the EEG electrodes into the cap of the electrode cap, the entire EEG electrodes are inserted into the pre-drilled holes in the cap, so that the opening 102 on the side of the blocking layer 10 of the front probe faces the scalp. The absorbent layer 20 forms a stable contact with the scalp through the opening 102. The EEG signal is transmitted to the circuit board of the electrode base 100 through the absorbent layer 20, the conductive layer 30, and the interface layer 40, and then output to the amplifier through the shielded cable.

[0058] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0059] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A front-end probe for electroencephalogram (EEG) electrodes, characterized in that, The front-end probe includes a blocking layer, a liquid absorption layer, a conductive layer, and an interface layer; The barrier layer forms a receiving cavity, and the liquid-absorbing layer, the conductive layer and the interface layer are all disposed in the receiving cavity. Along the direction from the outer wall to the inner wall of the barrier layer, the liquid-absorbing layer, the conductive layer and the interface layer are arranged in sequence. The liquid-absorbing layer covers at least part of the conductive layer, and the conductive layer covers at least part of the interface layer. The interface layer is used to connect the elastic support rod of the EEG electrode. Along a first direction, the barrier layer has an opposing top and bottom, the top having a through hole for the elastic support rod to pass through, the bottom being a closed structure, and the side of the barrier layer having an opening opposite at least a portion of the liquid-absorbing layer, the side of the barrier layer being the portion between the top and bottom of the barrier layer.

2. The front-end probe according to claim 1, characterized in that, The bottom of the barrier layer is configured as a pointed arc, a rounded arc, or a wedge-shaped structure.

3. The front-end probe according to claim 1, characterized in that, The top of the barrier layer is configured as a pointed arc, a rounded arc, or a wedge-shaped structure.

4. The front-end probe according to claim 1, characterized in that, The liquid-absorbing layer has a porous structure.

5. The front-end probe according to claim 1, characterized in that, The conductive layer includes at least one of a conductive metal and a conductive non-metal.

6. The front-end probe according to claim 1, characterized in that, The interface layer is provided with a connecting part, which is used to connect with the elastic support rod.

7. A type of electroencephalogram (EEG) electrode, characterized in that, The EEG electrode includes an electrode base, at least one elastic support rod, and at least one front probe according to any one of claims 1-6; The first end of the elastic support rod is fixed to the electrode base, and the second end of the elastic support rod passes through the through hole and is connected to the interface layer.

8. The EEG electrode according to claim 7, characterized in that, When the elastic support rod is not deformed, there is an angle between the central axis of the elastic support rod and the center line of the electrode base.

9. The EEG electrode according to claim 7, characterized in that, When the front probe contacts the scalp surface, and the elastic support rod is not deformed, the angle between the center line of the front probe and the tangent at the contact point between the scalp surface and the front probe is a first angle; when the elastic support rod is deformed, the angle between the center line of the front probe and the tangent at the contact point between the scalp surface and the front probe is a second angle, and the second angle is smaller than the first angle.

10. The EEG electrode according to claim 9, characterized in that, The first angle is greater than or equal to 60° and less than or equal to 85°, and the second angle is greater than 0° and less than or equal to 45°.

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