CN108309291A - A kind of flexible contact electrode for encephalograms and preparation method thereof - Google Patents

Abstract

The invention belongs to electrophysiologicalsignal signal detection technical field, specially a kind of flexible electrode for encephalograms and preparation method thereof.Electrode for encephalograms is made of flexible silicon gel electrode piece and electrode base.Flexible silicon gel electrode piece upper layer is flexible layer of silica gel, and lower layer is composite conductive layers, and the electrode slice after cutting includes circular electrode and connection handle；Electrode base includes：The fixing nut of the outer fixed card buckle of electrode slice, electrode cable, brain electricity cap fixed pedestal, electrode slice outer fixed card buckle, electrode cable fixing buckle；Wherein, it is buckled outside electrode slice and silica gel flexible electrical pole piece is fixed on electrode base, be fixed by outer fixed card buckle fixing nut.Electrode cable is closely pressed with flexible silicon gel electrode piece by the high spot for buckling inner wall outside electrode slice, and is fixed on brain electricity cap fixed pedestal by fixed card buckle fixing nut.The present invention has good contact, and convenient, comfortable to wear, impedance is low between electrode-skin, and electric conductivity is excellent, can collect high quality EEG signals.

Description

A kind of flexible contact EEG electrode and preparation method thereof

technical field

The invention belongs to the technical field of electrophysiological signal detection, and in particular relates to an electroencephalogram electrode and a preparation method thereof.

Background technique

Electroencephalogram (Electroencephalogram, EEG) signal is a synthesis of potential information generated by the physiological activities of neuron cells on the surface of the cerebral cortex or scalp. machine interface (BCI), fatigue detection and other fields. It is considered to be the main method for detecting epileptic seizures, psychogenic non-epileptic seizures, migraine, encephalopathy and other diseases [2], and it is also an important basis for the diagnosis of sleep disorders. However, the amplitude of the EEG signal is generally less than 100 μV [3], so the capture of the EEG signal puts forward very high requirements on the EEG electrode itself and the subsequent conditioning circuit. Among them, the post-stage conditioning circuit technology has become mature. In contrast, due to the complex electrical characteristics of electrodes and the special requirements for bioelectrical signal acquisition, research on EEG electrodes is in the ascendant.

In the prior art, EEG electrodes can be divided into two types: wet electrodes and dry electrodes. Wet electrodes refer to electrodes that need to be used with conductive paste. Through the previous skin preparation and the application of conductive paste at the collection site, a metal-electrolyte interface is formed between the electrode and the surface of the human skin, thereby reducing the ultra-high electrical impedance of the skin and obtaining a signal with a high signal-to-noise ratio. The existing wet electrodes are represented by Gold Cup Electrode [4] and Ag/AgCl electrode [5]. The gold cup electrode is prepared by electroplating gold metal on the basis of pure silver electrodes, which overcomes the oxidation problem of pure silver electrodes after long-term use. When in use, it is necessary to use conductive paste to connect the gold cup electrode and the skin, wait for sufficient contact and the signal is stable before collecting the signal. As a standard electrode for EEG signal acquisition, it has the advantages of excellent electrical 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 reactions. In addition, cleaning after the experiment is also very troublesome. As for the Ag/AgCl electrode, it is widely used in the industry because of its convenient preparation, low price, stable electrical signal baseline, strong anti-interference ability and other electronic characteristics. However, due to the phenomenon of dehydration and drying of the conductive gel in the electrode, its electrical characteristics will change when it is used for a long time, and large noise and errors will be introduced in high-precision experiments.

In order to solve the problems of wet electrodes, various researches are devoted to the development of dry electrodes that do not require the use of conductive paste and conductive gel. Since dry electrodes do not require operations such as skin preparation and application of conductive paste, they are very suitable for future health monitoring, rehabilitation, disease diagnosis and treatment, and brain-computer interface BCI and other fields. Microneedle electrodes [6] are the most commonly used dry electrodes in EEG acquisition technology. The microneedle electrode is an electrode designed and developed using microneedle technology. It manufactures an array of microneedle structures on the surface of materials such as silicon, metal, polymer, and glass through microfabrication methods, and directly penetrates the stratum corneum to reduce its Effect of ultra-high electrical impedance on signal acquisition. It is more convenient and reliable to use, has smaller impedance and smaller electrochemical characteristics, and is more conducive to long-term measurement. But the disadvantage is that it should avoid damage to the dermis and nerves and blood vessels when using it. At the same time, although other fabric electrodes have a good application in wearable ECG and EMG signal acquisition systems, when they are applied to EEG acquisition, the contact impedance due to the poor contact caused by the hair and the impedance effect of the skin Further increase makes the acquisition of EEG signals more difficult.

In order to overcome the shortcomings of traditional wet electrodes such as complex operation, difficulty in long-term wearable signal acquisition, and poor signal quality of dry electrodes, this invention proposes a flexible dry electrode based on a silica gel substrate. The electrode is comfortably and tightly combined with the scalp. At the same time, due to the use of highly conductive materials, it is possible to obtain high-quality original signals without using conductive paste or conductive gel. After the test and demonstration of the electrical performance of the electrode, it is shown that the electrode has the advantages of comfortable wearing, easy operation, high sensitivity and precision, and is suitable for health monitoring, wearable EEG signal acquisition and other fields.

references

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

[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.

[3] Oohashi, T., Kawai, N., Honda, M., Nakamura, S., Morimoto, M.,Nishina, E., & Maekawa, T. (2002). Electroencephalographic measurement of possession trance in the field. Clinical Neurophysiology, 113(3), 435-445.

[4] 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.

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

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

Contents of the invention

The purpose of the present invention is to provide a novel flexible contact EEG electrode with excellent electrical conductivity, strong anti-interference ability, convenient use, comfortable wearing, and low production cost and its preparation method.

The flexible contact EEG electrode provided by the present invention is composed of two parts: a flexible silicone electrode piece D and an electrode base; its structure is shown in Fig. 2 and Fig. 4 . Wherein, the flexible silicone electrode sheet has a double-layer structure, the upper layer is a flexible silicone layer, and the lower layer is a composite conductive layer. Functionally, the flexible silicone electrode sheet D is composed of a circular electrode and a connecting handle connected to the circular electrode; The electrode base includes: electrode wire A, fixing nut B, electrode wire fixing buckle C, EEG cap fixing base E, electrode sheet external fixing buckle F; wherein:

The EEG cap fixing base E is used to place the flexible silicone electrode sheet D and the electrode wire A; the shape of the EEG cap fixing base E is basically cylindrical, and it is provided with a connecting handle and a connecting handle for placing the flexible silicone electrode sheet D on it. The placement groove at the front end of the electrode wire A; located on the upper part of the placement groove, there is a wire fixing groove for fixing the electrode wire A; the lower edge of the EEG cap fixing base E is a convex spherical surface; the flexible silicone electrode piece D One side of the circular electrode part without conductive material is closely attached to the spherical surface of the lower part of the EEG cap fixing base E; the other end of the connecting handle of the flexible silicone electrode sheet D, which is coated with a conductive layer, is in contact with one end of the electrode wire A, and is fixed on the electrode wire A. In the placement groove on the cap fixing base E;

The fixing nut B is used to fix the outer fixing buckle F of the electrode sheet;

The electrode wire A is used to transmit the electrical signal collected on the flexible silicone electrode sheet D, and connect to the external circuit board; a part of the electrode wire A is placed in the wire fixing groove, and is fixed on the electrode wire by the electrode wire fixing buckle C. The EEG cap is fixed on the base E;

The electrode wire fixing buckle C is used to fix the electrode wire A on the EEG cap fixing base E;

The outer fixing buckle F of the electrode sheet is a cavity, the shape of the cavity matches the shape of the EEG cap fixing base E, the upper opening of the cavity matches the lower opening of the fixing nut B, and the inner side is provided with a bulge G, Its lower edge is a through hole, and the external fixing buckle F of the electrode sheet is provided with an external thread matching the internal thread of the fixing nut B; the EEG cap fixing base E is located in the cavity of the external fixing buckle F of the electrode piece; the electrode piece The bulge G on the inner side of the external fixing buckle F will press and fix the silicone electrode sheet D in the groove on the EEG cap fixing base E and the front end of the electrode wire A tightly; the electrode sheet external fixing buckle F will The flexible silicone electrode sheet D is fixed on the bottom of the EEG cap fixing base E, and the spherical surface at the bottom of the EEG cap fixing base E pushes a part of the round electrode of the flexible silicone electrode sheet D out of the electrode sheet outside the fixing buckle F Outside the edge hole, so that the surface of the electrode pad can fully contact the scalp.

The fixing nut B and the electrode sheet external fixing buckle F are threadedly combined to fix the electric cap fixing base E, the flexible silicone electrode sheet D and the electrode lead A joint inside it.

In the present invention, a groove is arranged on the fixing base E of the EEG cap, and its size is: length 4mm, width 5mm, depth 1mm.

In the present invention, the bulge G on the inside of the electrode wire fixing buckle C has a width of 5 mm, and the height of the bulge apex from the inner surface of the electrode sheet outer fixing buckle F is 0.5 mm.

In the present invention, the diameter of the circular part of the flexible silicone electrode sheet is slightly larger than the inner aperture of the lower bottom surface of the outer fixing buckle F of the electrode sheet. The inner diameter of the through hole on the lower bottom surface of the electrode piece external fixing buckle F is 12-14mm.

In the present invention, the vertex of the circular electrode part of the flexible silicone electrode sheet D protrudes 1.5mm-2mm outside the lower edge hole of the outer fixing buckle F of the electrode sheet to ensure that the surface of the electrode sheet fully contacts the scalp.

When in use, the electrode is close to the scalp, the electrode is soft, and the signal is good, which ensures the property of long-term repeated wearing.

The preparation method of the flexible contact EEG electrode provided by the invention, the specific steps are:

(1) Preparation of flexible silicone electrode sheet:

(1) Apply the metal nanowire dispersion droplet on the surface of a smooth substrate, heat at 60-100°C, and dry to form a three-dimensional conductive network film; here, the metal nanowires can be silver nanowires, copper nanowires, gold nanowires, etc. wire, etc., the concentration of the metal nanowire dispersion can be 1-10 wt%; the substrate can be glass, silicon wafer, ceramics, etc.;

(2) Pour the silica gel solution onto the surface of the three-dimensional conductive network film prepared in step (1), and let it stand for 0.5-5 hours. After the solution completely penetrates into the voids of the three-dimensional conductive network, heat it at 60-100°C for 2-12 hours, and wait for After the silica gel is completely cured, it is carefully peeled off from the surface of the substrate to obtain a flexible silica gel electrode material; here, the silica gel solution can be selected from polydimethylsiloxane (PDMS), styrene-butadiene-styrene block copolymer (SBS) or polyurethane (PU), etc.;

(3) Cut the prepared flexible silicone electrode material into an electrode shape: including a circular part and a connecting handle; as shown in Figure 3;

Generally, the diameter a of the circular part of the electrode sheet is 12mm-14mm. The length b of the connecting handle is 4mm, and the width c is 5mm. Wherein, the thickness e of the conductive layer is 1-10 μm, and the thickness d of the silica gel layer is 100-500 μm.

(2) Assembly of dry flexible EEG electrodes:

(1) Insert the electrode lead (B) through the gap between the EEG cap fixing base E and the fixing nut B;

(2) Place the front part of the electrode lead A (about 4mm in length) in the placement groove on the EEG cap fixing base E; the electrode lead uses FPC;

(3) Insert the electrode wire fixing buckle C into the wire fixing groove on the EEG cap fixing base E, fix the electrode wire A placed in the groove on the EEG cap fixing base E, and place Put the front end (4mm length) of the electrode lead A into the placement groove;

(4) Insert the connection handle of the cut flexible silicone electrode sheet D into the gap between the electrode wire A and the inner wall of the placement groove;

(5) Align the bulge (G) on the inner wall of the external fixing buckle F of the electrode piece with the placement groove, put the outer fixing buckle F of the electrode piece on the outside of the fixing base E of the EEG cap, and ensure the flexible silicone electrode piece D is 1.5mm-2mm higher than the ground under the external fixing buckle F of the electrode sheet due to the extrusion of the spherical surface of the lower part of the EEG cap fixing base;

(6) Rotate the fixing nut B to fix the outer fixing buckle F of the electrode piece.

The flexible EEG electrode of the present invention has good contact, convenient wearing mode, comfortable wearing experience, good body surface skin fit, low electrode-skin impedance, excellent electrical conductivity, and can collect high-quality brain data. electric signal. In addition, the production cost of the flexible silicone electrode sheet is extremely low, which can greatly reduce the cost of use. The invention has the advantages of simple and convenient operation, short production period and easy large-scale production.

Features of the invention

The flexible contact EEG electrode has good contact flexibility.

The silicone flexible electrode has good flexibility and can be bent at any angle without affecting its conductivity.

The electrode base is designed as a detachable structure, which ensures the ease of replacement of the silicone flexible electrode sheet.

The silicone flexible electrode sheet and the wire are pressed together by the conductive buckle fixed on the outer buckle of the electrode sheet, without any welding, glue and good conductivity.

A silicone base is provided on the contact surface between the electrode base and the silicone flexible electrode sheet, which further ensures the flexible contact between the user's scalp and the silicone flexible electrode sheet.

The model of the flexible contact EEG electrode has good electrical conductivity and can collect high-quality EEG signals.

Description of drawings

Figure 1. The physical picture of the electrode.

Figure 2. Schematic diagram of the internal structure of the new flexible EEG electrode.

Figure 3. Flexible silicone electrode sheet dimensions.

Figure 4. Schematic diagram of flexible electrode installation steps.

Figure 5. Electron micrographs of the cross-section of the flexible silicone electrode and the surface of the conductive layer.

Figure 6. Skin-electrode impedance comparison of flexible EEG electrodes, Ag/AgCl electrodes, and gold cup electrodes in the Fp1 region.

Figure 7. Skin-electrode impedance comparison of flexible EEG electrodes, Ag/AgCl electrodes, and gold cup electrodes in the F3 region.

Figure 8. Comparison of EEG signals collected by flexible EEG electrodes, Ag/AgCl electrodes, and gold cup electrodes in the Fp1 area.

Figure 9. Frequency-domain comparison of EEG signals collected by flexible EEG electrodes, Ag/AgCl electrodes, flexible silicone motors, and gold cup electrodes in the Fp1 region.

Figure 10. Comparison of the EEG signals collected by the flexible EEG electrode and the Jinbei electrode in the F3 area.

Figure 11. Frequency-domain comparison of EEG signals collected by flexible EEG electrodes and Jinbei electrodes in the F3 area.

Labels in the figure: A is the electrode wire, B is the buckle fixing nut, C is the fixing buckle, D is the flexible silicone electrode piece, E is the fixing base of the EEG cap, F is the outer fixing buckle of the electrode piece, G is the inner bulge .

Detailed ways

Prepare new flexible EEG electrodes according to the above steps:

(1) Preparation of flexible silicone electrode sheet:

(1) 2 ml of silver nanowire (Ag NWs) dispersion with a concentration of 5 wt% was drop-coated on the surface of a 5 cm × 5 cm glass substrate, and heated and dried at 60 °C for 10 min to obtain a three-dimensional silver nanowire conductive network film;

(2) Pour 1ml of PDMS solution onto the surface of the silver nanowire conductive network film prepared in step (1), let it stand for 1h, then heat and cure at 60°C for 5h, and carefully peel off the PDMS from the surface of the glass substrate after the PDMS is completely cured to obtain a flexible silicone electrode , its specific structure is shown in Figure 2, the pure PDMS silica gel layer is used as a flexible substrate with a thickness of 100 μm, and the Ag NWs/PDMS composite layer is used as a conductive layer with a thickness of 10 μm. It should be noted that the three-dimensional conductive network of Ag NWs is embedded in the surface of PDMS, rather than simply covering its surface, so it has good adhesion under the condition of satisfying the conductivity, and can withstand bending, twisting, Even in the case of stretching, it will not fall off, which fully meets the application requirements of EEG electrodes.

Install and test the new flexible silicone EEG electrodes according to Figure 4. First, insert the FPC electrode wire A through the gap between the EEG cap fixing base E and the electrode sheet external fixing buckle fixing nut B; then place the front part of the FPC electrode wire A about 4mm long on the EEG cap fixing base In the placement slot on E; then insert the electrode wire fixing buckle F into the card slot above the placement slot on the EEG cap fixing base; then connect the flexible silicone electrode sheet D cut according to Figure 3 Insert the handle into the gap between the FPC electrode wire A and the inner wall of the placement groove; in addition, after aligning the bulge on the inner wall of the outer fixing buckle F of the electrode piece with the placement groove, put the outer fixing buckle F of the electrode piece on the EEG cap Fix the outer surface of the base, and ensure that the flexible silicone electrode is about 1.5mm higher than the lower edge of the outer fixing buckle F of the electrode piece due to the extrusion of the spherical surface of the lower part of the EEG cap fixing base; finally, fix the fixing nut of the outer fixing buckle of the rotating electrode piece B Fix the external fixing buckle F of the electrode piece.

At present, the EEG electrodes widely used clinically are gold cup electrodes or Ag/AgCl electrodes, often with conductive gel attached to the contact part of the electrode and the skin to improve the fit and conductivity, and reduce the skin-electrode impedance. However, as the use time increases, the conductive gel tends to harden, and the related performance decreases significantly.

The flexible EEG electrode proposed by the present invention does not require conductive gel, and the mechanical properties of the material itself enable it to maintain good contact with the skin for a long time. The results of the electrochemical workstation test show that the skin-electrode impedance of the proposed electrode is comparable to that of the gold cup electrode and Ag/AgCl electrode in the range of 0.1 Hz-100k Hz, while almost all physiological signals (such as EEG, ECG, EMG) etc.) are distributed in the range of 0.1 Hz to 1k Hz. It does not require conductive gel, so it has obvious advantages over Ag/AgCl electrodes in the application scenarios of wearable devices. Compared with Jinbei electrodes, the quality of the collected data is comparable, and it is suitable for long-term monitoring. Figure 6 and Figure 7 respectively show the skin-electrode impedance between the electrode proposed in this patent and the gold cup electrode and Ag/AgCl electrode in the range of 0.1 Hz-100k Hz at Fp1 (left frontal pole, no hair attached) and F3 ( The contrast of the position of the left forehead, with hair attached). In the 0.1Hz to 200KHz frequency band, the flexible silicone electrode proposed by the patent has the smallest skin electrode interface impedance, which is about half of the gold cup electrode (about 15K ohms) near the DC frequency band, and the impedance distribution is similar to the EEG standard gold cup electrode. The smaller skin electrode interface impedance makes the internal resistance of the equivalent signal source smaller, thereby reducing the signal distortion problem caused by the large internal resistance of the signal source. Among the three electrodes, the Ag/AgCl electrode has the largest impedance, which means that it is difficult to use the Ag/AgCl electrode to collect EEG signals in practical applications.

In addition, for electrodes, in addition to excellent electrical performance, the ultimate goal is to be able to collect effective signals. Therefore, a medical grade commercial polysomnography PSG (Compumedics Grael) device was used for signal acquisition verification. The experimental conditions are as follows: In order to ensure strict variable control, the subjects are required to wash before the experiment to ensure that the test is not disturbed by sweat, oil stains, etc., and the test is over within one hour. Constant (skin contact and impedance state will not change greatly over time to cause the test to fail), the sampling frequency is 256Hz. In the Fp1 area, three kinds of electrodes were used for comparative testing. In the F3 area, due to the interference of the hair, the quality of the signal collected by the Ag/AgCl electrode was poor, so in the F3 area only the comparison test between the new flexible EEG electrode and the Jinbei electrode was carried out. In this experiment, time domain and frequency domain analysis are performed on the collected original signal, and the feasibility of electrode design is demonstrated according to its characteristics. Figure 8 and Figure 9 respectively show the comparison of the EEG signals collected by the new flexible EEG electrode, the Ag/AgCl electrode, and the Jinbei electrode in the Fp1 area and the frequency domain analysis. Figure 10 and Figure 11 compare the EEG signals collected by the new flexible EEG electrode and the Jinbei electrode in the F3 area and the frequency domain analysis. From the perspective of time domain, the two have the same waveform, indicating the validity of the signal acquisition of the two. From the perspective of the frequency domain, the spectrum structures of the two collected signals are completely consistent, which once again demonstrates the rationality of the electrode design.

Claims (9)

1. a kind of flexible contact electrode for encephalograms, which is characterized in that by flexible silicon gel electrode piece（D）With electrode base two parts structure At；The flexible silicon gel electrode piece is double-layer structure, and upper layer is flexible layer of silica gel, and lower layer is composite conductive layers, functionally, soft Property silica gel electrode slice（D）The connection handle being connect by a circular electrode and with circular electrode is constituted；The electrode base includes：Electrode Conducting wire（A）, fixing nut（B）, electrode cable fixing buckle（C）, brain electricity cap fixed pedestal（E）, the outer fixed card buckle of electrode slice（F）； Wherein：

The brain electricity cap fixed pedestal（E）, for disposing flexible silicon gel electrode piece（D）And electrode cable（A）；Brain electricity cap is fixed Pedestal（E）Shape is substantially cylindrical, which is provided with for placing flexible silicon gel electrode piece（D）Connection handle and electrode cable（A）Before The placement groove at end；Positioned at placement groove top, it is equipped with fixed electrode cable（A）Conducting wire fixed groove；Brain electricity cap is fixed Pedestal（E）Lower edge is the sphere curved surface of evagination；Flexible silicon gel electrode piece（D）Circular electrode portion be close on one side without conductive material In brain electricity cap fixed pedestal（E）Lower spherical curved surface；Flexible silicon gel electrode piece（D）The connection handle other end be coated with conductive layer On one side with electrode cable（A）End thereof contacts, be fixed on electric cap fixed pedestal（E）On placement groove in；

The electrode cable（A）, for transmitting flexible silicon gel electrode piece（D）The upper collected electric signal of institute, and connect external electrical Road plate；Electrode cable（A）A part lead and be placed in conducting wire fixed groove, by electrode cable fixing buckle（C）It is fixed on brain electricity Cap fixed pedestal（E）On；

The electrode cable fixing buckle（C）For by electrode cable（A）It is fixed on brain electricity cap fixed pedestal（E）On；

The outer fixed card buckle of the electrode slice（F）, internal is cavity, the cavity shape and brain electricity cap fixed pedestal（E）Shape Match, cavity is suitable for reading and fixing nut（B）Lower mouth matching, inside be equipped with protuberance（G）, lower edge is through-hole, and outside electrode slice Fixed card buckle（F）It is equipped with and fixing nut（B）The matched external screw thread of internal thread；Brain electricity cap fixed pedestal（E）Outside electrode slice Fixed card buckle（F）Cavity in；The outer fixed card buckle of electrode slice（F）The protuberance of inside（G）Brain electricity cap fixed pedestal will be located at（E）On Dispose the property silica gel electrode slice in groove（D）Connection handle and electrode cable（A）Front end closely presses, is fixed；It is fixed outside electrode slice Buckle（F）By flexible silicon gel electrode piece（D）It is fixed on brain electricity cap fixed pedestal（E）Bottom, also, brain electricity cap fixed pedestal（E） The spherical of bottom is by flexible silicon gel electrode piece（D）The part of circular electrode release the outer fixed card buckle of electrode slice（F）Lower edge Outside hole, so that electrode slice surface can be adequately exposed to scalp；

Fixing nut（B）With fixed card buckle outside electrode slice（F）By electric cap fixed pedestal after engaged through the thread（E）And flexible silica gel Electrode slice（D）And electrode cable（A）Connector is fixed therein portion.

2. flexible contact electrode for encephalograms according to claim 1, which is characterized in that the brain electricity cap fixed pedestal（E）On Placement groove, size are：Long 4mm, wide 5mm, deep 1mm.

3. flexible contact electrode for encephalograms according to claim 1, which is characterized in that the electrode cable fixing buckle（C）It is interior The protuberance of survey（G）, width 5mm, the outer fixed card buckle of the protuberance vertex distance electrode slice（F）Inner surface height be 0.5mm.

4. flexible contact electrode for encephalograms according to claim 1, which is characterized in that the flexible silicon gel electrode piece rounded portions Diameter is divided to be more than the outer fixed card buckle of electrode slice（F）Bottom surface internal orifice dimension；The outer fixed card buckle of electrode slice（F）Bottom surface through-hole internal diameter ruler Very little is 12-14mm..

5. flexible contact electrode for encephalograms according to claim 1, which is characterized in that the flexible silicon gel electrode piece（D）'s The vertex of circular electrode portion protrudes from the outer fixed card buckle of electrode slice（F）The outer 1.5mm-2mm of lower marginal pore, to ensure electrode slice surface It is adequately exposed to scalp.

6. a kind of preparation method of flexible contact electrode for encephalograms as described according to one of claim 1-5, which is characterized in that tool Body step is：

（One）It is prepared by flexible silicon gel electrode piece：

（1）Metal nanometer line dispersant liquid drop is coated in smooth substrates surface, is heated at 60-100 DEG C, it is dry, it forms three-dimensional and leads Electric network film；

（2）Silica gel solution is poured into step（1）The three-dimensional conductive network thin-film surface being prepared stands 0.5-5h, waits for molten Liquid completely penetrates in three-dimensional conductive network gap, and 2-12h is heated at 60-100 DEG C, from substrate table after silica gel is fully cured Face is removed, and flexible silicon gel electrode material is obtained；

（3）The flexible silicon gel electrode material being prepared is cut into electrode shape：Including circular portion and connection handle；

（Two）The assembling of dry flexibility electrode for encephalograms：

（1）By electrode cable（A）From brain electricity cap fixed pedestal（E）With fixing nut（B）Between gap penetrate；

（2）By electrode cable（A）Fore-end is placed in brain electricity cap fixed pedestal（E）On resettlement groove in；

（3）By electrode cable fixing buckle（C）It is inserted into brain electricity cap fixed pedestal（E）On be located at conducting wire fixed groove in, will put Set the electrode cable in groove（A）It is fixed on brain electricity cap fixed pedestal（E）On, and by electrode cable（A）Fore-end is put Enter to dispose in groove；

（4）The flexible silicon gel electrode piece that will be cut（D）Connection handle be inserted into electrode cable（A）With the sky between resettlement groove inner wall In gap；

（5）By fixed card buckle outside electrode slice（F）Bump pad on inner wall（G）It is aligned in placement groove, by fixing card outside electrode slice Button（F）It is sleeved on brain electricity cap fixed pedestal（E）Outside, and ensure flexible silicon gel electrode piece（D）Because of brain electricity cap fixed pedestal lower ball Shape curved surface squeezes and is higher than the outer fixed card buckle of electrode slice（F）Lower ground 1.5mm-2mm；

（6）Rotary fixing screw is female（B）, by fixed card buckle outside electrode slice（F）It is fixed.

7. preparation method according to claim 6, which is characterized in that step（1）In, the metal nanometer line is received for silver Rice noodles, copper nano-wire or nanowires of gold, a concentration of 1-10 wt% of metal nanometer line dispersion liquid.

8. preparation method according to claim 6, which is characterized in that step（2）In, the silica gel solution is selected from poly- two Methylsiloxane, Styrene-Butadiene-Styrene Block Copolymer or polyurethane.

9. preparation method according to claim 6, which is characterized in that step（3）In, electrode slice circular portion diameter a is 12mm-14mm；Connection handle length b is 4mm, and width c is 5mm；Wherein, conductive layer thickness e is 1-10 μm, and layer of silica gel thickness d is 100-500 μm。