Method for manufacturing semi-dry electrode, semi-dry electrode and electroencephalogram signal acquisition system

Abstract

The application relates to the technical field of electroencephalogram signal collection, and discloses a manufacturing method of a semi-dry electrode, a semi-dry electrode and an electroencephalogram signal collection system. The manufacturing method comprises the following steps: pouring a preset amount of liquid gel into a pouring cavity of a pouring mold; the surface of a support is adapted to conduct electricity, and the support is provided with a contact part; inserting the contact part into the pouring cavity to wait for the gel to solidify, and a gap exists between the inner wall of the pouring cavity and the contact part; after the liquid gel is solidified, the solid gel adheres to the contact part to form an electroencephalogram electrode; when the electroencephalogram electrode is in close contact with the scalp, the surface of the scalp and the electroencephalogram electrode are in an electrically connected state. In actual application, the solidified gel can directly pass through the hair and be in close contact with the scalp, so that good electrical contact is formed between the surface of the scalp and the electroencephalogram electrode, and the accuracy of signal transmission is ensured. Therefore, the problem of short circuit between electrode points is avoided.

Description

Technical Field

[0001] This invention relates to the field of electroencephalogram (EEG) signal acquisition technology, specifically to a method for manufacturing a semi-dry electrode, the semi-dry electrode, and an EEG signal acquisition system. Background Technology

[0002] Currently, there are three methods for acquiring EEG signals: wet electrodes, semi-dry electrodes, and dry electrodes. While traditional wet electrodes can acquire high-quality EEG signals, they are cumbersome to use and require a long preparation time. Furthermore, conductive gel needs to be injected into the acquisition site using a syringe before signal acquisition. Therefore, the overall preparation time is relatively long.

[0003] When using dry electrodes for data acquisition, the contact principle is employed, with a rigid material directly contacting the scalp to collect EEG signals. Generally, the tighter the contact with the scalp, the better the acquired EEG signal. Therefore, to ensure signal quality, the dry electrodes need to be in close contact with the scalp, leading to pain and a poor experience for the subject. Furthermore, due to the high interfacial impedance between the dry electrodes and the cerebral cortex, the signal quality recorded by dry electrodes is generally lower than that of wet electrodes.

[0004] Based on this, traditional semi-dry electrodes replace conductive paste with electrolyte, which shortens the preparation time, but still has problems such as difficulty in controlling the amount of electrolyte released, which can easily cause short circuits between electrode points. Summary of the Invention

[0005] In view of this, the present invention provides a method for manufacturing a semi-dry electrode, a semi-dry electrode and an EEG signal acquisition system to solve the problem that traditional semi-dry electrodes are prone to short circuits between electrode points.

[0006] In a first aspect, the present invention provides a method for manufacturing a semi-dry electrode, the method comprising:

[0007] A predetermined amount of liquid gel is poured into the pouring cavity of the casting mold;

[0008] The surface of the support is suitable for conductivity, and the support is provided with a contact portion; the contact portion is inserted into the casting cavity and the gel is allowed to solidify, and there is a gap between the inner wall of the casting cavity and the contact portion;

[0009] After the liquid gel solidifies, the solid gel adheres to the contact area to form an EEG electrode; when the EEG electrode is in close contact with the scalp, there is an electrical connection between the surface of the scalp and the EEG electrode.

[0010] Beneficial effects: This invention, through the application of gel on the contact portion of the support, leverages the gel's excellent contact properties and flexibility. In practical applications, the cured gel can directly penetrate the hair and make close contact with the scalp, thus forming a good electrical contact between the scalp surface and the EEG electrodes, ensuring accurate signal transmission. Compared to traditional semi-dry electrodes, there is no need to control the electrolyte release, thereby avoiding the problem of short circuits between electrode points.

[0011] In one optional embodiment, the pouring of a predetermined amount of liquid gel into the pouring cavity of the casting mold includes:

[0012] The bracket, base mold, and bracket mold are printed using 3D printing technology; wherein the casting mold is formed by the interlocking of the base mold and the bracket mold.

[0013] The base mold has a hemispherical groove, and the bracket mold has a bracket cavity suitable for the bracket to be inserted. When the base mold and the bracket mold are fastened together, the hemispherical groove and the bracket cavity communicate to form the casting cavity.

[0014] The base mold has a sealing groove formed on its top edge, and the bracket mold has a protrusion formed on its bottom edge that is suitable for embedding into the sealing groove. When the base mold and the bracket mold are fastened together, the protrusion is embedded in the sealing groove.

[0015] The surface of the sealing groove is covered with a first sealing element, and the surface of the protrusion is covered with a second sealing element. When the base mold and the bracket mold are fastened together, the first sealing element and the second sealing element are in contact.

[0016] The liquid gel is stirred to ensure it is evenly mixed.

[0017] After the liquid gel is mixed evenly, the liquid gel is poured into the casting cavity along the inner wall edge of the support cavity;

[0018] As the amount of liquid gel in the casting cavity increases, it eventually reaches a preset quantity mark in the casting cavity; the preset quantity mark is located at half the overall depth of the casting cavity.

[0019] Beneficial Effects: This invention utilizes 3D printing technology to print the bracket, base mold, and bracket mold. Compared to traditional mold-making equipment, this significantly reduces production costs and allows for rapid prototyping, improving production efficiency. Furthermore, by incorporating sealing grooves and protrusions, the overall sealing of the casting mold is enhanced when the base mold and bracket mold are joined together, preventing gel leakage during casting. Simultaneously, pouring the gel only to half the total depth of the casting cavity ensures that the gel can completely cover the bracket while preventing gel overflow during insertion.

[0020] In one alternative embodiment, the surface of the support is adapted to conduct electricity, including:

[0021] A conductive coating is uniformly applied to the surface of the support.

[0022] After coating is completed, the bracket is placed in an oven for drying, so that a uniform conductive layer is formed on the surface of the bracket.

[0023] Beneficial effects: By coating the surface of the scaffold with a conductive coating, this invention can save production costs compared to directly using conductive materials. Furthermore, the conductive coating further improves the conductivity between the scaffold and the gel, thereby forming a good electrical contact between them and ensuring the accuracy of signal transmission.

[0024] In one optional embodiment, the conductive coating is conductive silver paste.

[0025] In one alternative embodiment, the bracket is provided with a contact portion, including:

[0026] The bracket is also provided with a support plate, and the edge of the support plate is provided with a plurality of contact portions, so that the bracket as a whole forms a claw structure.

[0027] Beneficial effects: By setting multiple contact parts and forming a claw-like structure, the embodiments of the present invention can select multiple contact points within a certain range to acquire EEG signals, thereby increasing the number of EEG signals acquired and improving the quality of the acquired signals to a certain extent.

[0028] In one alternative embodiment, the extension direction of the contact portion is perpendicular to the plane where the support disk is located.

[0029] In one optional embodiment, the contact portion has a columnar structure, and the length direction of the columnar structure is the extending direction of the contact portion.

[0030] In one optional embodiment, inserting the contact portion into the casting cavity and waiting for the gel to solidify includes:

[0031] Insert the contact part into the casting cavity and cure it at room temperature or in an oven.

[0032] In one alternative embodiment, after the liquid gel solidifies, the end of the gel away from the support is in a hemispherical shape, which is adapted to contact the scalp.

[0033] Beneficial effects: In this embodiment of the invention, the end of the gel furthest from the scaffold is shaped into a hemispherical structure. Since the gel is directly in contact with the scalp when acquiring EEG signals, the hemispherical end allows the entire surface of the hemispherical structure to contact the scalp, thereby increasing the contact area between each contact portion and the scalp, and thus improving the quality of the acquired signal.

[0034] Secondly, the present invention also provides a semi-dry electrode, which is manufactured by the method for manufacturing a semi-dry electrode as described in any of the above embodiments.

[0035] Thirdly, the present invention also provides an electroencephalogram (EEG) signal acquisition system, which includes an EEG cap and an acquisition device communicatively connected to the EEG cap. The EEG cap is provided with a plurality of semi-dry electrodes as described in the above embodiments. A communication line is welded to the tail of the semi-dry electrodes, and the semi-dry electrodes transmit the acquired EEG signals to the acquisition device through the communication line. Attached Figure Description

[0036] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the overall structure of the bracket in an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of the overall structure of the bracket mold in an embodiment of the present invention;

[0039] Figure 3 This is a schematic diagram of the overall structure of the base mold in an embodiment of the present invention;

[0040] Figure 4 This is a schematic diagram of the preparation process of the semi-dry electrode in an embodiment of the present invention;

[0041] Figure 5 This is a schematic diagram of the overall structure of the EEG electrodes in an embodiment of the present invention.

[0042] Explanation of reference numerals in the attached figures:

[0043] 1. Bracket; 11. Support plate; 12. Contact part;

[0044] 2. Support mold; 21. Support cavity;

[0045] 3. Base mold; 31. Hemispherical groove;

[0046] 4. Gel. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0049] In the description of this invention, it should be noted that, unless otherwise explicitly 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; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0050] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0051] Brain-computer interface (BCI) technology is a technology that establishes an independent information output pathway between the human or animal brain and a computer or other electronic device. With the continuous development of integrated circuits and communication transmission, BCI technology is gradually being applied to fields such as neuroscience research, detection and treatment of neurological diseases, smart wearables, and leisure and entertainment.

[0052] Currently, there are three methods for acquiring EEG signals: wet electrodes, semi-dry electrodes, and dry electrodes. While traditional wet electrodes can acquire high-quality EEG signals, they are cumbersome to use and require a long preparation time. Conductive gel needs to be injected into the acquisition site using a syringe before acquisition. Even experienced lab technicians need approximately half an hour to prepare for acquiring 64 channels of EEG signals; furthermore, subjects need to wash their hair after the experiment, affecting their experience and limiting the applicability. Therefore, the overall preparation time is long. Dry electrodes, utilizing a contact principle, use a rigid material to directly contact the scalp to acquire EEG signals. Generally, the tighter the contact with the scalp, the better the acquired EEG signal. Therefore, to ensure signal quality, the dry electrode needs to be in close contact with the scalp, leading to pain and a poor experience for the subject. Additionally, due to the high interfacial impedance between the dry electrode and the cerebral cortex, the signal quality recorded by dry electrodes is generally lower than that of wet electrodes. Based on this, traditional semi-dry electrodes replace conductive paste with electrolyte, which shortens the preparation time, but still has problems such as difficulty in controlling the amount of electrolyte released, which can easily cause short circuits between electrode points.

[0053] In view of this, the present invention provides a method for manufacturing a semi-dry electrode, a semi-dry electrode and an EEG signal acquisition system to solve the problem that traditional semi-dry electrodes are prone to short circuits between electrode points.

[0054] The following is combined Figures 1 to 5 The following describes embodiments of the present invention.

[0055] According to an embodiment of the present invention, in one aspect, the present invention provides a method for fabricating a semi-dry electrode, the method comprising:

[0056] S1. Pour a predetermined amount of liquid gel 4 into the pouring cavity of the pouring mold;

[0057] In this embodiment of the invention, the casting cavity in the casting mold needs to match the contact portion 12 of the support 1. Simultaneously, the inner diameter of the casting cavity needs to be larger than the outer diameter of the contact portion 12. That is, after the contact portion 12 is inserted into the casting cavity, there is a gap between the contact portion 12 and the casting cavity. Thus, as the contact portion 12 continues to penetrate deeper into the casting cavity, the length of the gel 4 submerging the contact portion 12 also continuously increases.

[0058] Furthermore, in this embodiment of the invention, the gel 4 can be a conductive hydrogel 4. The hydrogel 4 is a highly hydrophilic three-dimensional network structure gel 4 that rapidly swells in water and can retain a large volume of water without dissolving in this swollen state. Due to the presence of a cross-linked network, the hydrogel 4 can swell and retain a large amount of water; the amount of water absorbed is closely related to the degree of cross-linking. The higher the degree of cross-linking, the lower the water absorption. This characteristic is very similar to that of soft tissue. The water content in the hydrogel 4 can be as low as a few percent or as high as 99%. The aggregated state of the gel 4 is neither completely solid nor completely liquid. The behavior of a solid is that it can maintain a certain shape and volume under certain conditions; the behavior of a liquid is that the solute can diffuse or permeate from the hydrogel 4. It should be noted that the hydrogel 4 in this embodiment uses commercially available hydrogel 4, and the fabrication of the hydrogel 4 is not a point of protection in this solution.

[0059] Of course, this embodiment is merely an example of the specific type of gel 4, but it is not intended to limit it. Those skilled in the art can make changes according to the actual situation, as long as the same technical effect can be achieved.

[0060] S2. The surface of the support 1 is suitable for conductivity, and the support 1 is provided with a contact portion 12; the contact portion 12 is inserted into the casting cavity and the gel 4 is waited for to solidify, and there is a gap between the inner wall of the casting cavity and the contact portion 12;

[0061] Specifically, in this embodiment of the invention, the support 1 can be entirely made of conductive material, or a conductive coating can be applied to the surface of the support 1, or an additional conductive layer can be provided on the surface of the support 1. This enables the surface of the support 1 to achieve conductivity. Of course, this embodiment is merely an example illustrating a specific method for achieving conductivity on the surface of the support 1, and is not intended to limit the scope. Those skilled in the art can modify it according to actual circumstances, as long as the same technical effect is achieved.

[0062] The support 1 can also be made of engineering plastics or plastics. Specifically, engineering plastics have excellent comprehensive properties, high rigidity, low creep, high mechanical strength, good heat resistance, and good electrical insulation. They can be used for a long time in harsh chemical and physical environments and can replace metals as engineering structural materials. Engineering plastics can be divided into two categories: general-purpose engineering plastics and special-purpose engineering plastics. The main varieties of general-purpose engineering plastics include polyamide, polycarbonate, polyoxymethylene, modified polyphenylene ether, and thermoplastic polyester. Special-purpose engineering plastics mainly refer to engineering plastics with heat resistance up to 150℃ or higher, and the main varieties include polyimide, polyphenylene sulfide, polysulfone, aromatic polyamide, polyarylate, polyphenylene ester, polyaryletherketone, liquid crystal polymers, and fluoropolymers, etc.

[0063] Furthermore, the main component of plastic raw materials is carbon-containing compounds. Plastics are primarily composed of high-molecular-weight synthetic resins, infused with various auxiliary materials or additives. Under specific temperature and pressure conditions, they possess plasticity and fluidity, allowing them to be molded into specific shapes and maintain those shapes under certain conditions. Moreover, plastics exhibit excellent electrical, thermal, and acoustic insulation properties, as well as arc resistance, making them outstanding in thermal insulation, sound insulation, sound absorption, vibration absorption, and noise reduction.

[0064] Furthermore, the bracket 1 is additionally provided with a contact portion 12, which can be fixedly connected to the bracket 1 or detachably connected. For fixed connection, welding, bonding, or other methods can be used. For detachable connection, screw holes, clips, or magnetic attraction can be used for fixing.

[0065] The following provides an example of a detachable connection method. For instance, additional fixing plates can be provided around the edges of the bracket 1. Those skilled in the art can change the number of fixing plates according to actual needs, such as 1, 2, 3, 4, etc. Screw holes are then made on the fixing plates. Another screw hole is then made on the contact part 12 at the corresponding screw hole position. Screws are then passed through the screw holes on the fixing plates and the screw holes on the contact part 12 in sequence to connect the bracket 1 to the contact part 12. Furthermore, when using a snap-fit ​​and slot method for fixing, snap-fits can be additionally provided around the edges of the bracket 1. Those skilled in the art can change the number of snap-fits according to actual needs, such as 1, 2, 3, 4, etc. Slots that can cooperate with the snap-fits are then made on the contact part 12 at the corresponding snap-fit ​​positions. The snap-fits on the bracket 1 are then directly inserted into the slots on the contact part 12, thereby connecting the bracket 1 to the contact part 12. When fixing by magnetic attraction, additional magnetic sheets can be set around the edge of the bracket 1. Those skilled in the art can change the number of magnetic sheets according to the actual situation, such as 1, 2, 3, 4, etc. Then, opposite magnetic sheets that can attract the magnetic sheets are made on the contact part 12 at the position corresponding to the magnetic sheets. Then, the magnetic sheets on the bracket 1 are directly aligned with the opposite magnetic sheets embedded in the contact part 12, thereby magnetically connecting the bracket 1 and the contact part 12.

[0066] Of course, this embodiment is merely an example of fixed connection and detachable connection, but it does not limit the scope of the invention. Those skilled in the art can make changes according to the actual situation to achieve the same technical effect.

[0067] Furthermore, in this embodiment of the invention, as described in step S1 above, there is a gap between the contact portion 12 and the inner wall of the casting cavity. Thus, as the contact portion 12 continues to penetrate deeper into the casting cavity, the length of the gel 4 submerging the contact portion 12 also continuously increases. This allows the gel 4 to be completely adhered to the contact portion 12.

[0068] S3. After the liquid gel solidifies, the solid gel adheres to the contact portion to form an EEG electrode. When the EEG electrode is in close contact with the scalp, the surface of the scalp and the EEG electrode are electrically connected.

[0069] After the liquid gel 4 solidifies, the solid gel can be tightly bound to the contact portion 12. This ensures that a good electrical contact can be formed between the solid gel and the scaffold 1 during the acquisition of EEG signals, thus guaranteeing the accuracy of signal transmission.

[0070] Furthermore, since gel 4 has a certain degree of elasticity after curing, when the EEG electrodes are in close contact with the scalp, gel 4 can expand the contact area between the electrodes and the scalp, forming a good electrical contact between the scalp surface and the EEG electrodes.

[0071] With this configuration, this embodiment of the invention utilizes the good contact and flexibility of gel 4 on the contact portion 12 of the support 1. In practical applications, the cured gel 4 can directly penetrate the hair and make close contact with the scalp, thus forming a good electrical contact between the scalp surface and the EEG electrodes, ensuring the accuracy of signal transmission. Compared to traditional semi-dry electrodes, there is no need to control the electrolyte release, thereby avoiding the problem of short circuits between electrode points.

[0072] In an optional embodiment, step S1, which involves pouring a predetermined amount of liquid gel 4 into the casting cavity of the casting mold, specifically includes the following steps:

[0073] S11. The bracket 1, the base mold 3, and the bracket mold 2 are printed using 3D printing technology; wherein the casting mold is formed by the base mold 3 and the bracket mold 2 being fastened together.

[0074] 3D printing, also known as additive manufacturing or rapid prototyping, is a technology that uses digital model files as a basis and employs powdered metals or plastics and other bondable materials to construct objects layer by layer. 3D printing is typically achieved using digital material printers. It is commonly used in mold making and industrial design to create models, and is increasingly being used for the direct manufacturing of some products.

[0075] Furthermore, for the fastening method of the base mold 3 and the bracket mold 2, a snap-on and slot fastening method can be adopted. For example, multiple slots can be set at one end of the base mold 3, and multiple snaps can be set at one end of the bracket mold 2, so that the base mold 3 and the bracket mold 2 can be fastened together directly.

[0076] In this embodiment of the invention, the fastening method of the base mold 3 and the bracket mold 2 is merely an example, but it is not a limitation. Those skilled in the art can make changes according to the actual situation, as long as the same technical effect can be achieved.

[0077] S12. A hemispherical groove 31 is formed in the base mold 3, and a support cavity 21 suitable for the support 1 to be inserted is formed in the support mold 2. When the base mold 3 and the support mold 2 are fastened together, the hemispherical groove 31 and the support cavity 21 communicate to form the casting cavity.

[0078] like Figure 2 and Figure 3 As shown, in this embodiment of the invention, in actual assembly, the base mold 3 needs to be placed underneath, and the bracket mold 2 needs to be placed on top of the base mold 3, with the bracket cavity 21 and the hemispherical groove 31 aligned. The openings at both ends of the bracket cavity 21 are connected. After the base mold 3 and the bracket mold 2 are assembled together, the hemispherical groove 31 and the opening at one end of the bracket cavity 21 are aligned, thus forming a casting cavity. During the casting process, it is only necessary to pour the casting into the casting cavity from the opening at the other end of the bracket 1 along the inner wall edge of the bracket cavity 21.

[0079] Furthermore, the fastening method of the base mold 3 and the bracket mold 2 can also be an interference fit. For example, in S13, the top edge of the base mold 3 is formed with a sealing groove, and the bottom edge of the bracket mold 2 is formed with a protrusion suitable for embedding in the sealing groove. When the base mold 3 and the bracket mold 2 are fastened together, the protrusion is embedded in the sealing groove.

[0080] Specifically, in this embodiment of the invention, the protrusion and the sealing groove can be configured to have an interference fit, with the volume of the protrusion slightly larger than that of the sealing groove. As for the number of sealing grooves, this embodiment does not limit this; it can be 3, 4, 5, etc. Those skilled in the art can modify it according to actual circumstances, as long as the same technical effect is achieved.

[0081] S14. A first sealing element is provided on the surface of the sealing groove, and a second sealing element is provided on the raised surface. When the base mold 3 and the bracket mold 2 are fastened together, the first sealing element and the second sealing element are in contact.

[0082] Furthermore, in this embodiment of the invention, the first and second sealing elements can be sealing sheets or sealant. The first and second sealing elements not only prevent the liquid gel 4 from leaking between the adjacent mating surfaces of the base mold 3 and the support mold 2, but also prevent external impurities such as dust and moisture from entering the pouring cavity, thereby ensuring the cleanliness of the gel 4.

[0083] S15. Stir the liquid gel 4 to make the liquid gel 4 evenly mixed;

[0084] S16. After the liquid gel 4 is mixed evenly, as follows: Figure 4 As shown, liquid gel 4 is poured into the casting cavity along the inner wall edge of the support cavity 21;

[0085] S17, such as Figure 4 As shown, as the amount of liquid gel 4 in the casting cavity increases, it eventually reaches the preset amount scale line in the casting cavity; the preset amount scale line is located at half the overall depth of the casting cavity.

[0086] In this embodiment of the invention, the setting position of the preset quantity scale line is merely illustrative. Those skilled in the art can adjust the preset quantity scale line according to the actual insertion of the contact part 12 and the encapsulation position of the gel 4. This embodiment is merely illustrative and is not intended to limit the scope. For example, it can be adjusted to 1 / 3, 2 / 5, etc., of the overall depth of the casting cavity. Those skilled in the art can make changes according to the actual situation, as long as the same technical effect is achieved.

[0087] With this configuration, the embodiments of the present invention utilize 3D printing technology to print the bracket 1, base mold 3, and bracket mold 2. Compared to traditional mold-making equipment, this significantly reduces production costs, enables rapid prototyping, and improves production efficiency. Furthermore, by incorporating sealing grooves and protrusions, the overall sealing of the casting mold is improved when the base mold 3 and bracket mold 2 are joined together, preventing leakage of gel 4 during casting. Simultaneously, by pouring gel 4 only to half the total depth of the casting cavity, it ensures that gel 4 can cover the bracket 1 while preventing gel 4 from overflowing during insertion.

[0088] In an optional implementation, in step S2, the surface of the support 1 is adapted to conduct electricity, including:

[0089] S21. A conductive coating is uniformly applied to the surface of the bracket 1.

[0090] Conductive coatings can be formed using various coating methods, such as metallic conductive layers, conductive tapes, or other specialized coating materials, like conductive paste used to fill shielding gaps. They offer excellent static conductivity and act as a protective energy absorption layer. They also provide good shielding performance. There are two main types of conductive coatings: blended and transparent film. Blended conductive coatings incorporate fine-particle conductive materials into the coating filler, which are then brushed or sprayed onto the surface of insulating materials along with organic or inorganic binders and diluents to form a conductive layer with specific conductivity. Transparent film conductive coatings are transparent conductive films prepared using semiconductor compounds, such as tin oxide, indium oxide, cadmium oxide, cadmium stannate, etc., or by adding small amounts of fluorine or antimony to these compounds.

[0091] S22. After coating is completed, the bracket 1 is placed in an oven for drying, so that a uniform conductive layer is formed on the surface of the bracket 1.

[0092] With this configuration, the embodiments of the present invention can save production costs by coating the surface of the support 1 with a conductive coating, compared to directly using a conductive material. Moreover, coating with a conductive coating can further improve the conductivity between the support 1 and the gel 4, thereby forming a good electrical contact between the support 1 and the gel 4 and ensuring the accuracy of signal transmission.

[0093] In one optional embodiment, the conductive coating is conductive silver paste. This embodiment is merely an example illustrating a specific type of conductive coating, but it is not intended to limit the application. Those skilled in the art can modify it according to actual circumstances, as long as the same technical effect is achieved.

[0094] In one alternative implementation, such as Figure 1 As shown, the bracket 1 is provided with a contact portion 12, including:

[0095] The bracket 1 is also provided with a support plate 11, which has a disc-shaped structure. The support plate 11 has a plurality of contact portions 12 arranged circumferentially on its edge, so that the bracket 1 as a whole forms a claw-like structure.

[0096] With this configuration, the embodiments of the present invention can select multiple contact points within a certain range to acquire EEG signals by setting multiple contact parts 12 and forming a claw-like structure, thereby increasing the number of EEG signals acquired and improving the quality of the acquired signals to a certain extent.

[0097] In one alternative implementation, such as Figure 5 As shown, the extending direction of the contact portion 12 is perpendicular to the plane where the support disk 11 is located. The contact portion 12 has a columnar structure, and the length direction of the columnar structure is the extending direction of the contact portion 12.

[0098] Furthermore, in this embodiment of the invention, the contact portion 12 and the support plate 11 are rotatably connected. For example, the contact portion 12 and the support plate 11 are rotatably connected via a hinge shaft. In practical applications, technicians can manually adjust the angle between the contact portion 12 and the support plate 11 according to the specific circumstances of each tester, so that the contact portion 12 can make closer contact with the tester's scalp. Based on this, the contact portion 12 can be configured as a multi-joint structure, allowing technicians to adjust the distribution position of each contact portion 12 and the specific test position within the test area. Simultaneously, the angle between the contact portion 12 and the support plate 11 can be automatically driven by a drive device, as can the angles between the various joint structures on the contact portion 12. Specifically, the operation of the drive device is adjusted via a control panel, which has preset adjustment modules for the specific operating parameters of the drive device. This improves the work efficiency of technicians.

[0099] Furthermore, in this embodiment of the invention, a piezoelectric element can be provided at the end of the contact portion 12, that is, the end of the contact portion 12 closest to the scalp. The testing instrument can then be connected to the piezoelectric element via a communication line, and the testing instrument can also be integrated into a control panel. In this way, technicians can adjust the position and distribution of each contact portion 12 according to the pressure between each contact portion 12 and the tester's scalp, ensuring that each contact portion 12 can stably contact the scalp without causing excessive pressure on the tester, thus reducing pain caused by pressure from the contact portions 12. This improves the user experience for both technicians and testers.

[0100] In one alternative implementation, in step S2, as follows: Figure 4 As shown, inserting the contact portion 12 into the casting cavity and waiting for the gel 4 to solidify includes:

[0101] The contact portion 12 is inserted into the casting cavity and cured at room temperature or in an oven. This embodiment is merely an example of how the gel 4 is cured, and is not intended to limit the method. Those skilled in the art can modify the method according to actual conditions to achieve the same technical effect.

[0102] In one alternative implementation, such as Figure 5 As shown, after the liquid gel 4 solidifies, the end of the gel 4 away from the support 1 forms a hemispherical structure, which is suitable for contact with the scalp.

[0103] With this configuration, in this embodiment of the invention, the end of the gel 4 furthest from the support 1 is shaped into a hemispherical structure. Since the gel 4 is directly in contact with the scalp when acquiring EEG signals, the hemispherical structure allows its entire surface to contact the scalp after contact, thereby increasing the contact area between each contact portion 12 and the scalp, and thus improving the quality of the acquired signal.

[0104] In this embodiment, the end of the gel 4 furthest from the scaffold 1 can also be configured as a teardrop shape or an elliptical shape. Of course, this embodiment is merely illustrative and is not intended to limit the scope. Those skilled in the art can modify it according to actual circumstances, as long as the same technical effect is achieved.

[0105] Secondly, the present invention also provides a semi-dry electrode, which is manufactured by the method for manufacturing a semi-dry electrode as described in any of the above embodiments.

[0106] Thirdly, the present invention also provides an electroencephalogram (EEG) signal acquisition system, which includes an EEG cap and an acquisition device communicatively connected to the EEG cap. The EEG cap contains multiple semi-dry electrodes as described in the above embodiments, and a communication line is welded to the tail of each semi-dry electrode. The semi-dry electrodes transmit the acquired EEG signals to the acquisition device via the communication line. By matching the EEG cap, multiple semi-dry electrodes can be fabricated and fitted inside the EEG cap, thereby enabling the acquisition of EEG signals from multiple channels.

[0107] In practical applications, the semi-dry electrodes in this embodiment can be adjusted and modified in number and shape as needed to suit different application scenarios. For example, the number and arrangement of the electrode claws can be changed to adapt to different hair densities and scalp areas. Furthermore, the material and thickness of the gel 4 can be changed to improve the signal response and impedance matching performance of the semi-dry electrodes.

[0108] Furthermore, in practical applications, EEG signals used in brain-computer interfaces are generally classified into two categories: endogenous and exogenous. Steady-state visual evoked potentials (SVPs) are a typical exogenous signal or evoked potential, which are stable EEG oscillations induced by stable, periodically repeated visual stimuli presented according to a certain repetition pattern. The semi-dry electrodes mentioned in this embodiment can be used to acquire EEG signals induced by steady-state visual evoked potentials.

[0109] Steady-state visual evoked potential signals are used to construct a brain-computer interface. Canonical correlation analysis of filter banks, task-related component analysis, machine learning algorithms, and some other frequency identification methods are used to optimize the data, reduce noise, and improve the signal-to-noise ratio, thereby achieving high target classification accuracy and high information transmission rate in the brain-computer interface system.

[0110] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method of making a semi-dry electrode, comprising: include: A predetermined amount of liquid gel (4) is poured into the pouring cavity of the pouring mold. The surface of the support (1) is suitable for conducting electricity, and the support (1) is provided with a contact part (12); the contact part (12) is inserted into the casting cavity and the gel (4) is waited for to solidify, and there is a gap between the inner wall of the casting cavity and the contact part (12); After the liquid gel solidifies, the solid gel adheres to the contact area to form an EEG electrode; when the EEG electrode is in close contact with the scalp, there is an electrical connection between the surface of the scalp and the EEG electrode. The bracket (1) is provided with a contact portion (12), and the bracket (1) is also provided with a support plate (11). The support plate (11) is provided with a plurality of contact portions (12) around its edge, so that the bracket (1) as a whole forms a claw structure. The extension direction of the contact portion (12) is perpendicular to the plane where the support plate (11) is located. The contact portion (12) has a columnar structure, and the length direction of the columnar structure is the extension direction of the contact portion (12). The contact part (12) and the support plate (11) are rotatably connected; the angle between the contact part (12) and the support plate (11) is driven by the drive device, and the angle between the contact part (12) and the support plate (11) is adjusted according to the specific situation of each tester, so that the contact part (12) is in close contact with the scalp of the tester; The contact part (12) is configured as a multi-joint structure, and the distribution position of each contact part (12) and the specific test position in the test area are adjusted by the multi-joint structure; the angle between each joint structure on the contact part (12) is automatically driven; A piezoelectric pad is placed at the end of the contact part (12) near the scalp. The testing instrument is then connected to the piezoelectric pad via a communication line, and the testing instrument is integrated into the control panel. The position and distribution of each contact part (12) are adjusted according to the pressure between each contact part (12) and the scalp, so that each contact part (12) is stably in contact with the scalp, reducing the pain caused by the pressure applied by the contact part (12). The process of pouring a predetermined amount of liquid gel (4) into the pouring cavity of the casting mold includes: The bracket (1), base mold (3) and bracket mold (2) are printed using 3D printing technology; wherein the casting mold is formed by the base mold (3) and bracket mold (2) being fastened together. The base mold (3) has a hemispherical groove (31) formed therein, and the bracket mold (2) has a bracket cavity (21) suitable for the bracket (1) to be inserted therein. When the base mold (3) and the bracket mold (2) are fastened together, the hemispherical groove (31) and the bracket cavity (21) communicate to form the casting cavity. The base mold (3) has a sealing groove formed on its top edge, and the bracket mold (2) has a protrusion formed on its bottom edge that is suitable for embedding into the sealing groove. When the base mold (3) and the bracket mold (2) are fastened together, the protrusion is embedded in the sealing groove. The surface of the sealing groove is covered with a first sealing element, and the surface of the protrusion is covered with a second sealing element. When the base mold (3) and the bracket mold (2) are fastened together, the first sealing element and the second sealing element are in contact. Stir the liquid gel (4) to mix it evenly; After the liquid gel (4) is mixed evenly, the liquid gel (4) is poured into the casting cavity along the inner wall edge of the support cavity (21); As the amount of liquid gel (4) in the casting cavity increases, it reaches the preset amount scale line in the casting cavity; the preset amount scale line is located at half the overall depth of the casting cavity; The surface of the support (1) is adapted to conduct electricity, including: A conductive coating is uniformly applied to the surface of the bracket (1); After coating is completed, the bracket (1) is placed in an oven for drying, so that a uniform conductive layer is formed on the surface of the bracket (1); the conductive coating is conductive silver paste. The step of inserting the contact portion (12) into the casting cavity and waiting for the gel (4) to solidify includes: Insert the contact part (12) into the casting cavity and cure it at room temperature or in an oven; After the liquid gel (4) solidifies, the end of the gel (4) away from the support (1) forms a hemispherical structure, which is suitable for contact with the scalp.

2. A semi-dry electrode characterized by, It is manufactured by the method for manufacturing a semi-dry electrode as described in claim 1.

3. An electroencephalographic signal acquisition system, characterized by include: An EEG cap and a data acquisition device communicatively connected to the EEG cap, wherein the EEG cap is provided with a plurality of semi-dry electrodes as described in claim 1, and a communication line is welded to the tail of the semi-dry electrodes, and the semi-dry electrodes transmit the acquired EEG signals to the data acquisition device through the communication line.

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