An integrated flexible EEG cap that is easy to wear and comfortable to wear

Abstract

The present invention belongs to the technical field of electrophysiological signal detection, and specifically is an integrated flexible EEG cap that is convenient and comfortable to wear. The EEG cap of the present invention has a three-layer structure, with the outer layer being a fixed layer, the middle layer being a conductive layer, and the inner layer being an insulating shielding layer; the inner side of the fixed layer has a raised fulcrum with a hole, and the position corresponds to the position of the flexible EEG electrode; the outer side has a detachable hardware box for placing the corresponding hardware module; and a chin strap that plays a tightening and fixing role; the conductive layer is printed with flexible EEG electrodes with holes, wires, and corresponding lead-out interfaces; the insulating shielding layer has holes at the positions corresponding to the flexible EEG electrodes, and the other parts are insulated and have a shielding function. The EEG cap of the present invention directly integrates the EEG electrodes and the corresponding wiring together, has good contact, convenient wearing method, and comfortable wearing experience, and greatly simplifies the preliminary work of EEG monitoring.

Description

Technical Field

[0001] The present invention belongs to the technical field of physiological signal detection, and specifically relates to an integrated flexible electroencephalogram cap that is easy and comfortable to wear. Background Art

[0002] Electroencephalogram (EEG) signals are a combination of potential information generated by the physiological activities of neuronal cell bodies in the cerebral cortex or scalp surface. They contain rich rhythmic information of the brain [1] and can be widely used in the fields of brain disease diagnosis, rehabilitation, brain-computer interface (BCI), fatigue detection, etc. It is considered to be the main method for detecting epileptic seizures, psychological non-epileptic seizures, migraine, encephalopathy and other diseases [2]. It is also an important basis for the diagnosis of sleep disorders. At present, the EEG cap is usually put on first, and then the EEG electrodes are installed, represented by the Gold Cup Electrode [3] and Ag / AgCl electrode [4]. When using it, it is necessary to use conductive paste to connect the Gold Cup Electrode and the skin, and wait for full contact and stable signal before collecting the signal. As a standard electrode for EEG signal collection, it has the advantages of excellent conductivity, stable signal, and high signal-to-noise ratio. However, the application of conductive paste requires a lot of time with the help of medical staff, and long-term collection will cause discomfort to the subjects, and in severe cases, it will cause allergic redness and swelling. In addition, cleaning after the experiment is also very troublesome. After installing the electrodes, the electrode wires also need to be organized. Not only is the work cumbersome, but the wires will inevitably affect the subject's behavior and comfort.

[0003] In order to solve the problem of wet electrodes, various studies have been devoted to the development of dry electrodes that do not require the use of conductive paste or conductive gel. Since dry electrodes do not require skin preparation and the application of conductive paste, they are very suitable for future applications in health monitoring, rehabilitation, disease diagnosis and treatment, and brain-computer interface (BCI). Microneedle electrodes[5] are the most commonly used dry electrodes in EEG acquisition technology. However, when using them, it is necessary to avoid damaging the dermis and nerves and blood vessels. In order to solve the problem of wire connection, some wireless EEG devices have also appeared on the market, but these devices have specific usage scenarios and functions, and are bulky[6]. For example, the multi-claw structure is only suitable for use when standing or sitting, and is not suitable for use during sleep. In addition, the number of leads is small and cannot fully cover the entire brain function area.

[0004] In order to overcome the complex operation of traditional wet electrode EEG caps and the difficulty of long-term wearable signal collection, as well as the shortcomings of existing dry electrode wireless EEG caps, such as many restrictions and few leads, the present invention proposes an integrated flexible EEG cap that is easy to wear and comfortable to wear. The EEG cap has the full number of leads of traditional EEG caps, is easy to wear and comfortable, has few scene restrictions, greatly simplifies the preliminary work of EEG monitoring, and is suitable for health monitoring, wearable EEG signal collection and other fields.

[0005] References

[0006] [1] Han Fengtan, Zhu Xianfeng. Installation and maintenance of medical imaging equipment[M]. Beijing: People's Medical Publishing House, 2008:162-172.

[0007] [2] Acharya, D., Rani, A., & Agarwal, S. (2015, September). EEG dataacquisition circuit system Based on ADS1299EEG FE. In Reliability, InfocomTechnologies and Optimization (ICRITO)(Trends and Future Directions), 20154th International Conference on (pp. 1-5). IEEE.

[0008] [3] Tallgren, P., Vanhatalo, S., Kaila, K., &Voipio, J. (2005). Evaluation of commercially available electrodes and gels for recording ofslow EEG potentials. Clinical Neurophysiology, 116(4), 799-806.

[0009] [4] Verma, N., Shoeb, A., Bohorquez, J., Dawson, J., Guttag, J., &Chandrakasan, AP (2010). A micro-power EEG acquisition SoC with integrated feature extraction processor for a chronic seizure detection system. IEEEJournal of Solid-State Circuits, 45(4), 804-816.

[0010] [5] Liu Ran, Wang Xiaohao, & Zhou Zhaoying. (2004). MEMS microneedle array and its application in biomedicine. Journal of Biomedical Engineering, 21(3), 482-485.

[0011] [6] DSI-24 Wireless Dry Electrode EEG Acquisition System, http: / / www.neuracle.tech. Summary of the invention

[0012] The present invention aims to provide an integrated flexible electroencephalogram cap which is convenient and comfortable to wear, has few activity restrictions and is low-cost.

[0013] The integrated flexible EEG cap provided by the present invention is composed of a cap-shaped fixing layer, a conductive layer and an insulating shielding layer stacked in sequence from the outside to the inside. Figure 2-Figure 6 The distribution and number of electrodes in the figure are only for reference.

[0014] The fixing layer has a raised fulcrum with a hole on its inner side. The hole diameter is consistent with the opening diameter of the flexible EEG electrode. The position of the raised fulcrum corresponds to the position of the flexible EEG electrode, and is used to press the corresponding flexible EEG electrode on the conductive layer so that it can fully contact the skin. The outer side of the fixing layer has a detachable hardware box for placing the corresponding hardware module. The fixing layer is also provided with a chin strap for tightening. Its structure can be seen in Figure 4 .

[0015] The conductive layer is printed with flexible EEG electrodes with holes, wires and corresponding lead-out interfaces; the area of ​​the flexible EEG electrodes is slightly larger than the area of ​​the raised fulcrum on the inner side of the fixed layer, and after being pressed by the raised fulcrum, they can fully contact the skin to sense EEG signals; the wires leading out of the electrodes are also printed on the conductive layer together with the electrodes; the printed wires are gathered at the back, and the electrode interfaces are led out through a unified wiring, which is convenient for plugging and unplugging with the hardware module. Its structure can be seen in Figure 5 .

[0016] The insulating shielding layer is used to shield the electromagnetic interference of the human body and prevent the electrode wires on the conductive layer from accidentally contacting the human body. In the insulating shielding layer, there are openings at the positions corresponding to the protruding fulcrums of the fixed layer and the flexible EEG electrodes of the conductive layer. The area of ​​the openings is equivalent to the area of ​​the corresponding flexible EEG electrodes. The other parts are insulating layers with shielding functions. See the structure of Figure 6 .

[0017] In the present invention, the material of the fixing layer can be silicone, or a combination of flexible cloth, soft sponge, silicone and felt.

[0018] In the present invention, the shielding insulation layer is composed of one or a combination of the following: polyethylene film, tin foil, and electromagnetic shielding net.

[0019] In the present invention, in order to make the EEG cap washable, the conductive layer adopts a sandwich structure, including a flexible cloth base, a waterproof film printed or applied on the surface of the flexible cloth base, a printed circuit made on the surface of the film, and a waterproof film printed or applied on the printed circuit. The conductive layer is made in the following way: first, a film is printed or applied on the surface of the flexible cloth base, and then a conductive silver paste is printed on the surface of the film, and then a film is printed or applied after drying. The waterproof film can be a polyurethane film or the like.

[0020] In the present invention, the EEG electrode is a dry electrode.

[0021] In the present invention, the EEG electrodes and electrode wires can be made of silver nanowires (such as 2-7wt%) alone, or can be made of a mixture of metals, nanofillers and elastic polymers; wherein the metals are such as gold, silver, copper, nickel, etc., the nanofillers are such as nanowires, nanoparticles, nanosheets, etc., and the elastic polymers are such as polydimethylsiloxane, polystyrene block copolymers, polyurethane, fluororubber, etc.

[0022] The present invention is specifically worn and used:

[0023] The first step is to put on the integrated flexible EEG cap without tightening the chin strap;

[0024] The second step is to push the hair under the electrode through the openings on the fixing layer, the conductive layer, and the insulating shielding layer;

[0025] The third step is to completely fix the entire EEG cap by tightening the chin strap to complete the process of wearing the EEG cap;

[0026] The fourth step is to put the corresponding hardware module into the hardware box and connect it to the interface led out of the conductive layer. Since it is a fixed cable interface, it can be directly plugged in, and the connection is convenient and fast; the final effect can be seen in Figure 1 .

[0027] The integrated flexible EEG cap of the present invention is an integrated design, and the electrodes and the electrode cap do not need to be disassembled. During the entire use process, the installation and disassembly are simple and convenient. It can also be washed with water and reused many times. The EEG electrodes are printed dry electrodes, which do not require skin pretreatment and cause little damage to the skin. In addition, the integrated EEG cap has good contact, convenient wearing method, and comfortable wearing experience, providing a low-cost, easy-to-wear and comfortable EEG cap, which greatly simplifies the preliminary work of EEG monitoring. The present invention is easy to operate, has a short production cycle, and is easy to mass produce.

[0028] Features of the present invention:

[0029] The one-piece flexible EEG cap is of one-piece design, washable, and can be used repeatedly;

[0030] The EEG electrodes in the integrated flexible EEG cap have good contact flexibility;

[0031] The EEG electrodes in the integrated flexible EEG cap are dry electrodes, which do not require skin pretreatment and cause little damage to the skin;

[0032] The integrated flexible EEG cap uniformly prints electrodes and wires on the conductive layer, which effectively hides the originally messy wires.

[0033] The one-piece flexible EEG cap integrates EEG electrodes and wires in the cap, making it easy and quick to wear.

[0034] The electrode interfaces use a unified interface to ensure connectivity and facilitate plugging and unplugging;

[0035] The hardware box is detachable and can be selected according to specific usage scenarios, which has great flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is the rendering of an integrated flexible EEG cap.

[0037] Figure 2 Schematic diagram of the explosion of an integrated flexible EEG cap.

[0038] Figure 3 This is a cross-sectional layer diagram of an integrated flexible EEG cap.

[0039] Figure 4 This is a fixed layer diagram.

[0040] Figure 5 The conductive layer is shown.

[0041] Figure 6 This is a diagram of the insulation shielding layer.

[0042] Numbers in the figure: 1 is a fixing layer, 2 is a conductive layer, 3 is an insulating shielding layer, 4 is an opening on the inner side of the fixing layer, 5 is a raised fulcrum on the fixing layer, 6 is a chin strap, 7 is a hardware box, 8 is an opening on the conductive layer, 9 is a flexible EEG electrode, 10 is a wire, 11 is an electrode interface, and 12 is an opening on the shielding layer. DETAILED DESCRIPTION

[0043] The fixing layer is made of silicone, which has a fixing function and is a little soft, which improves the wearing comfort. Especially for the protruding fulcrum on the inside, it is a little elastic, which can better press the EEG electrode to ensure full contact between the electrode and the skin. The hardware box is made of ABS material and has a rectangular hole for connecting to the EEG electrode lead interface. The hardware box and the fixing layer are fixed by Velcro.

[0044] The conductive layer is first printed or applied with a film on the surface of the cloth base, and then the conductive silver paste is printed on the surface, and then printed or applied with another film after drying, so that the sandwich structure can be washed. The conductive silver paste, the main component of which is 5wt% silver nanowires (Ag NWs), has good flexibility while meeting the conductivity requirements. The end of the lead interface is made into an FPC interface to facilitate connection with the hardware module.

[0045] The insulating shielding layer is made by covering both sides of the tin foil with insulating films. The tin foil is mainly used to shield the interference of the human body on the signal, and the insulating film is used to isolate the electrical connection between the conductive layer and the shielding layer, and prevent the conductive layer and the shielding layer from accidentally contacting the human body. The insulating film is made of polyethylene film, which is a white translucent solid with good friction, high chemical stability, resistance to most acid and alkali erosion, low hygroscopicity, and outstanding insulation performance and radiation resistance. The insulating film made of polyethylene is tough and can still maintain its softness at 80°C.

[0046] The basic structure of the integrated flexible EEG cap of the present invention is formed by pressing the silicone fixing layer, the conductive fabric layer, and the polyethylene tin foil insulating shielding layer together from the outside to the inside. The hardware module can be placed by placing the hardware box in the middle of the fixing layer, thus realizing an integrated flexible EEG cap that does not affect the action and is completely independent and easy to wear.

[0047] Follow the above steps to put on:

[0048] The first step is to put on the integrated flexible EEG cap without tightening the chin strap;

[0049] The second step is to push the hair under the electrode through the openings on the fixing layer, the conductive layer, and the insulating shielding layer;

[0050] The third step is to completely fix the entire EEG cap by tightening the chin strap to complete the process of wearing the EEG cap;

[0051] The fourth step is to place the corresponding hardware module into the hardware box and connect it to the interface led out by the conductive layer. Since it is a fixed cable interface, it can be directly plugged in, and the connection is convenient and quick.

[0052] The hardware module in the fourth step uses an EEG signal acquisition and processing module with wireless communication function. The module is powered by a lithium battery, and the lithium battery is also placed in the hardware box. It is connected through the interface hole of the hardware box and the FPC interface of the conductive layer. In this way, a complete, easy-to-wear, integrated flexible EEG cap device is realized, which can realize the real-time acquisition of EEG signals. It has little impact on human behavior and can be worn for 24 hours for monitoring. Place the hardware box on the top of the head. The entire EEG cap is completely wireless and made entirely of flexible materials, providing a comfortable EEG monitoring experience even when sleeping. See the final effect. Figure 1 .

Claims

1. An integrated flexible EEG cap that is easy to wear and comfortable to wear, characterized in that: It is composed of a cap-shaped fixed layer, a conductive layer and an insulating shielding layer stacked in sequence from outside to inside, wherein: The fixing layer has a raised fulcrum with a hole on its inner side, the aperture of the hole is consistent with the aperture of the opening of the flexible EEG electrode, the position of the raised fulcrum corresponds to the position of the flexible EEG electrode, and is used to press the corresponding flexible EEG electrode on the conductive layer so that it can fully contact the skin; the outer side has a detachable hardware box for placing the corresponding hardware module; the fixing layer is also provided with a chin strap for tightening; The conductive layer is printed with flexible EEG electrodes with holes, wires and corresponding lead-out interfaces; the area of ​​the flexible EEG electrodes is slightly larger than the area of ​​the raised fulcrum on the inner side of the fixed layer, and after being pressed by the raised fulcrum, they can fully contact the skin to sense EEG signals; the wires leading out of the electrodes are also printed on the conductive layer together with the electrodes; the printed wires are gathered at the back, and the electrode interfaces are led out through a unified wiring arrangement, and connected to the hardware module by plugging and unplugging; The insulating shielding layer is used to shield electromagnetic interference from the human body and also prevent the electrode wires on the conductive layer from accidentally contacting the human body; in the insulating shielding layer, there are openings at positions corresponding to the protruding fulcrums of the fixed layer and the flexible EEG electrodes of the conductive layer, and the area of ​​the openings is equivalent to the area of ​​the corresponding flexible EEG electrodes; The fixing layer is composed of a single silica gel, or is composed of a flexible cloth, a soft sponge, silica gel, or felt; The EEG electrode is a dry electrode.

2. The integrated flexible EEG cap according to claim 1, characterized in that: The insulating shielding layer is composed of one or a combination of the following: polyethylene film, tin foil, and electromagnetic shielding net.

3. The integrated flexible EEG cap according to claim 1, characterized in that: The conductive layer adopts a sandwich structure, including a flexible cloth base, a waterproof film printed or applied on the surface of the flexible cloth base, a printed circuit made on the surface of the film, and a waterproof film printed or applied on the printed circuit.

4. The integrated flexible EEG cap according to claim 1, characterized in that: The EEG electrodes and electrode wires are made of silver nanowires, or a mixture of metal, nanofiller and elastic polymer; wherein the metal is gold, silver, copper or nickel, the nanofiller is nanowire, nanoparticle or nanosheet, and the elastic polymer is polydimethylsiloxane, polystyrene block copolymer, polyurethane or fluororubber.

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