CN103202690A - Flexible epicardium electrocardio-electrode chip and preparation method thereof - Google Patents

Abstract

The invention relates to a flexible epicardial ECG electrode chip, comprising a flexible base, an electrode unit, an electrode lead wire, a lead wire connection point and an insulating layer. For electrical connection, the insulating layer is arranged on the flexible base and covers the electrode leads, and the surface of the connection point between the electrode unit and the lead wires is not provided with an insulating layer. The invention also relates to a preparation method of a flexible epicardial electrocardiogram electrode chip. The above-mentioned electrode chip is composed of multiple electrode units arranged to form an electrode array, which can achieve the smallest spatial resolution down to the micron scale, has good softness and deformation ability, and can be attached to the surface of the heart to adapt to changes in the contour of the surface of the heart. The electrode forms a good attachment to the target area on the surface of the heart, and can effectively avoid damage such as extrusion and scratching caused by the electrode during heart movement. It can be used for qualitative diagnosis of heart diseases and precise location of lesions, providing objective basis for targeted treatment.

Description

Flexible epicardial ECG electrode chip and preparation method thereof

technical field

The invention relates to the field of medical equipment, in particular to a flexible epicardial ECG electrode chip, and also to a preparation method for the flexible epicardial ECG electrode chip.

Background technique

Routine ECG examination uses electrodes placed at 9 positions including hands, feet, and chest to obtain macroscopic body surface ECG signals and analyze them to determine heart disease. However, due to the asymmetry, irregularity, and non-uniformity of body tissues, the electrical signals generated by the heart have attenuation, distortion, and filtering effects in the process of being transmitted to the outside of the body. In addition, the electrocardiographic signal on the body surface is significantly different from the potential distribution on the heart surface in amplitude and phase, and many electrophysiological events may not necessarily be observed on the body surface. If multiple activation points appear in the myocardium at the same time, the superposition of multiple maps will make it difficult to determine the body surface potential. The surface ECG can only be observed qualitatively, but cannot accurately locate the lesion, thus limiting the accuracy of diagnosis. For complex heart diseases such as arrhythmia and myocardial ischemia, direct examination of the heart is required to locate and characterize the heart, so as to carry out targeted treatment.

As a method of accurately measuring, observing and analyzing the electrical activity of the heart, epicardial electrocardiography is different from conventional electrocardiography. It can not only make a macroscopic diagnosis, but also determine the precise location of the lesion, providing an objective basis for targeted treatment . It uses a multi-electrode system to cover the epicardial surface to record the electrical excitation of the heart at multiple points simultaneously. Due to the direct contact between the electrode array and the epicardium and the synchronous sampling of the ECG signal, it can objectively and accurately reflect the origin and propagation process of the ECG excitation.

In the United States, there are nearly five million heart failure patients, and as many as 550,000 new patients are diagnosed each year. Judging from the current situation, the morbidity and mortality of diseases with heart failure as the main cause in developed countries such as the United States mainly come from insufficient myocardial infarction mediated by replacement stem cells.

Compared with surface ECG recordings, epicardial multichannel ECG systems can provide information on asymmetric ventricular repolarization and are useful for monitoring ECG changes during cardiac regeneration. At present, foreign epicardial ECG studies are trying to use more electrode points to obtain more accurate data on the sequence and distribution of myocardial activation. Due to the large number of electrodes and the large amount of data, most of them use off-line analysis methods for electrophysiological research, which are difficult to apply clinically.

In the extraction of biomedical information, electrodes play the role of transducers, which can guide the bioelectric changes produced by biological organisms and change ion currents into electronic currents. Needle-shaped electrodes were first used for ECG collection, but needle-shaped electrodes were limited to local recordings. Later, with the deepening of research, epicardial ECG mainly used sheet-shaped electrodes that are easy to operate.

At present, the main substrate materials used for epicardial electrode pads are mostly silicone rubber and thermoplastics, which are convenient for multi-site detection. The base material of the electrode should have good flexibility and compliance, and can adapt to the contraction and relaxation of the heart. The size and relative spacing of the electrodes must meet the measurement requirements, and at the same time prevent damage to the epicardium. Although silicone rubber and thermoplastic substrates can meet the above requirements, with the increase of electrodes, the electrode leads are easy to be confused and broken, which increases the difficulty of production and use, and also affects the adhesion between electrode points and epicardium. In addition, some people use medical gauze soaked in physiological saline as the base material of the electrode. Before the operation, the electrode is evenly sutured on the gauze. The diameter of the electrode reaches 1mm, and the spacing is 3mm. Wire) or stainless steel (stainless steel wire with a diameter of 1.5mm), the pole spacing of existing epicardial electrodes is generally 1-5.6mm. But there will be the same problem in use.

Recently, there are also researches on designing the electrodes so that the electrode points are uniformly distributed on the flexible printed circuit board, and the surface of the electrode points is exposed to copper foil and treated with chemical gold plating. The lead-out line of each electrode and the flexible plate form a whole, and the raw material of the electrode sheet is polyimide, and the abutment line is enhanced by reducing the thickness to the micron scale. The electrode points are gold-plated on the outside of copper to prevent oxidation after long-term storage, while ensuring good contact. However, limited by the performance of the material itself, the polyimide film cannot be stretched and folded, and the local strain tolerance is less than 1%. Even if the flexibility of the microelectrode array can be improved by continuously reducing the thickness of the polyimide film, this increases the difficulty of electrode processing. Due to the constraints of the process, the processing size of the electrode has to be increased, resulting in the resolution of the electrode. In addition, the thickness of the polyimide substrate is reduced, which also reduces the mechanical strength and operability of the microelectrode array.

Contents of the invention

Based on this, it is necessary to provide a flexible epicardial ECG electrode chip for the problems existing in the traditional epicardial electrode sheet.

A flexible epicardial ECG electrode chip, comprising: a flexible base, an electrode unit, an electrode lead, a lead connection point and an insulating layer, the electrode unit, the electrode lead and the lead connection point together form an electrode assembly, and the electrode assembly is set On the flexible base, the electrode unit is connected to the lead connection point via the electrode lead to realize electrical connection, the insulating layer is arranged on the flexible base and covers the electrode lead, and the electrode unit is used for electrical connection On the surface of the heart, the material of the flexible base and the insulating layer is polydimethylsiloxane.

In one of the embodiments, the electrode assembly includes an electrode layer, and the material of the electrode layer is one of gold, titanium, and copper.

In one of the embodiments, the electrode assembly further includes a primer layer, the electrode layer is arranged on the primer layer, and the material of the primer layer is titanium, chromium, or contains one or more of these two elements. Two alloys.

In one of the embodiments, the electrode unit further includes a modification layer, the modification layer is arranged on the surface of the electrode unit facing away from the flexible substrate, and the material of the modification layer is platinum, iridium, or contains these two elements One or two alloys or compounds, or one of polypyrrole, poly(3,4-ethylenedioxythiophene), and polyaniline.

In one embodiment, the thickness of the part of the flexible substrate located at the electrode unit is much smaller than the thickness of other regions of the flexible substrate.

In one of the embodiments, the cross-section of the flexible substrate is a rectangle, the electrode units correspond to the connection points of the lead wires one by one, the electrode assembly includes two rows symmetrical about the perpendicular line of the rectangle, and the electrodes The unit and the corresponding lead wire connection point are located on the same side of the mid-perpendicular line, the electrode unit is located near the mid-perpendicular line, and the corresponding lead wire connection point is located near the side of the rectangle parallel to the mid-perpendicular line, The middle part of the flexible epicardial ECG electrode chip forms an inward depression on the side facing away from the insulating layer.

It is also necessary to provide a method for preparing a flexible epicardial ECG electrode chip.

A method for preparing a flexible nerve bundle electrode, comprising the following steps: Step 1, setting polydimethylsiloxane on a rigid substrate to form a flexible substrate; Step 2, forming an electrode assembly on the flexible substrate, the electrode assembly Including lead wire connection points, electrode units for electrically connecting the surface of the heart, and electrode leads electrically connecting the lead wire connection points and electrode units; step 3, setting a polydimethylsiloxane covering the electrode assembly on the flexible base Siloxane forms an insulating layer, and forms an opening at the position of the electrode unit and the lead connection point of the insulating layer, exposing the electrode unit and the lead connection point; Step 4, separating the flexible substrate from the rigid substrate to obtain The flexible epicardial ECG electrode chip.

In one embodiment, the second step includes: preparing a mask with a hollow pattern in the shape of the electrode assembly; attaching the mask tightly to the flexible substrate; Depositing a base layer on the flexible base of the mask; depositing an electrode layer on the base layer; removing the mask from the flexible base.

In one of the embodiments, after the third step, it also includes the step of coating a modified layer on the surface of the electrode unit, and the material of the modified layer is platinum, iridium, or contains one or more of these two elements. Two alloys or compounds, or one of polypyrrole, poly(3,4-ethylenedioxythiophene), and polyaniline.

In one of the embodiments, the rigid substrate is a glass boss.

The above-mentioned flexible epicardial ECG electrode chip has good flexibility and deformation ability, accurate recording position, tight contact and good repeatability. In addition, while ensuring the micron-scale processing accuracy and spatial resolution of the electrode array, 90% of one-dimensional deformation and 20% of two-dimensional deformation can be achieved, and a good conformal effect can be achieved without greatly reducing the thickness of the substrate. Realize the consistent attachment of the microelectrode array and the surface of the heart, and improve the sensitivity. At the same time, the good flexible matching performance with the heart can effectively reduce the risk of the chip causing damage to the epicardium. In addition, the chip can still maintain good electrical performance under folding, twisting and stretching conditions, which improves the matching with the heart.

Description of drawings

Fig. 1 is the structural representation of flexible epicardial ECG electrode chip in an embodiment;

Fig. 2 is a sectional view along the dotted line 6 shown in Fig. 1;

Fig. 3 is the flow chart of the preparation method of flexible epicardial ECG electrode chip in an embodiment;

Fig. 4 is the flow chart of the preparation method of flexible epicardial ECG electrode chip in embodiment 1;

Fig. 5 is the structural representation of flexible epicardial ECG electrode chip in embodiment 2;

Fig. 6 is a sectional view along the dotted line 12 shown in Fig. 5;

Fig. 7 is the application schematic diagram of flexible epicardial ECG electrode chip in embodiment 2;

8 is a flow chart of the method for preparing the flexible epicardial ECG electrode chip in Example 2.

Detailed ways

In order to make the objects, features and advantages of the present invention more comprehensible, specific implementations of the present invention will be described in detail below in conjunction with the accompanying drawings.

Example 1:

1 is a schematic structural view of the flexible epicardial ECG electrode chip in Embodiment 1. The flexible epicardial ECG electrode chip includes a flexible base 1 , an insulating layer 2 , an electrode unit 3 , electrode leads 4 and lead connection points 5 . The electrode lead 4 is electrically connected to the electrode unit 3 and the lead welding spot 5 , and one electrode unit 3 , one electrode lead 4 and one lead welding spot 5 together form an electrode assembly. The electrode assembly is arranged on the flexible substrate 1 , and the insulating layer 2 is arranged on the flexible substrate 1 and covers the electrode leads 4 . The electrode unit 3 is used to electrically connect the heart, and the lead connection point 5 is used to realize the connection between the ECG electrodes and the external circuit. FIG. 2 is a cross-sectional view along the dotted line 6 shown in FIG. 1. In this embodiment, the electrode unit 3 and the lead connection point 5 are exposed to the outside, and no insulating layer is provided on the surface. The number of electrode units is 10, distributed in a matrix of 2*5. It can be understood that the size, spacing, and quantity of the electrode units 3 can be adjusted according to actual application requirements. The line width, spacing, and wiring method of the electrode leads 4 can be adjusted with full consideration of the rationality of the wiring. The size and spacing of the lead connection points 5 can be adjusted according to actual application requirements. The lead connection points 5 correspond to the electrode units 3 one by one, and the number is the same.

The material of the flexible substrate 1 and the insulating layer 2 is polydimethylsiloxane (polydimethylsiloxane). Polydimethylsiloxane has good flexibility, deformation ability and good biocompatibility, and can ensure the processing accuracy and spatial resolution of the flexible epicardial ECG electrode chip.

The above-mentioned flexible epicardial ECG electrode chip is composed of multiple electrode units 3 arranged to form an electrode array, which can achieve the smallest spatial resolution down to the micron scale, has good softness and deformation ability, can be attached to the surface of the heart, and adapts to the surface of the heart. The change of the contour can not only ensure good adhesion between the electrode and the target area on the surface of the heart, but also effectively avoid damage such as extrusion and scratching caused by the electrode during heart movement. It can be used for qualitative diagnosis of heart diseases and precise location of lesions, providing objective basis for targeted treatment.

Fig. 3 is the flow chart of the preparation method of flexible epicardial ECG electrode chip in an embodiment, comprises the following steps:

S110 , disposing polydimethylsiloxane on a rigid substrate to form a flexible substrate 1 .

The rigid substrate can be made of glass, silicon wafer, etc., and mainly plays a supporting role. In this embodiment, a silicon wafer (which can be in any crystal orientation) is used as the rigid substrate, and polydimethylsiloxane is provided on the surface of the silicon wafer by spin coating. There are mainly two methods for changing the thickness of the flexible substrate 1 : one is to change the spin coating speed, and the other is to change the concentration of polydimethylsiloxane.

S120 , forming electrode units 3 , electrode leads 4 and lead connection points 5 on the flexible substrate 1 .

Fabrication is carried out on the flexible substrate 1 using micro-processing techniques (including thin film preparation techniques, photolithography techniques, etching techniques, etc.). An electrode unit 3 , an electrode lead 4 and a lead connection point 5 form an electrode assembly, and the electrode lead 4 electrically connects the electrode unit 3 and the lead connection point 5 . In one embodiment, the electrode assembly at least includes an electrode layer, and the material of the electrode layer is one of gold, titanium, and copper. In one embodiment, the electrode assembly further includes a primer layer, the electrode layer is disposed on the primer layer, and the material of the primer layer is titanium, chromium, or an alloy containing one or both of these two elements. In one of the embodiments, the electrode unit 3 also includes a modification layer, the modification layer is arranged on the surface of the electrode unit 3 facing away from the flexible substrate 1, and the material of the modification layer is platinum, iridium, or contains one or more of these two elements. Two alloys or compounds, or one of polypyrrole, poly(3,4-ethylenedioxythiophene), and polyaniline.

S130, arrange polydimethylsiloxane covering the electrode assembly on the flexible substrate 1 to form an insulating layer 2, and form an opening at the position of the electrode unit 3 and the lead wire connection point 5 of the insulating layer 2, and connect the electrode unit 3 to the lead wire Point 5 is revealed.

The insulating layer 2 can also be provided by spin coating, and the thickness of the insulating layer 2 can also be adjusted by changing the spin coating speed or changing the concentration of polydimethylsiloxane.

S140, separating the flexible substrate 1 from the rigid substrate to obtain a flexible epicardial ECG electrode chip.

The flexible nerve bundle electrode prepared by the method for preparing the flexible nerve bundle electrode has good size adaptability, and is easy to realize the normalized design of the device.

Provide a kind of preparation method of the flexible epicardium electrocardiogram electrode chip among the embodiment 1 again, see Fig. 4, comprise the following steps:

S210, spin-coat a layer of polydimethylsiloxane on the silicon wafer with any crystal orientation as the flexible substrate 1 .

S220, preparing a mask, forming a hollow pattern of the electrode assembly on the mask, and placing the mask on the flexible substrate 1 to form a close attachment.

S230, firstly depositing a titanium film on the flexible substrate 1 as an underlayer by electron beam evaporation, and then depositing a gold film on the underlayer by thermal evaporation as an electrode layer.

The underlying layer and the electrode layer are limited by the hollow pattern of the mask to form the shape of the electrode assembly.

S240, removing the mask.

S250, using thick photoresist to perform photolithography, and preparing a photoresist sacrificial layer at the position of the electrode unit 3 and the position of the lead connection point 5 .

S260, spin coating a layer of polydimethylsiloxane as the insulating layer 2.

The thickness of the insulating layer 2 should be much lower than the thickness of the thick photoresist sacrificial layer.

S270, removing the photoresist sacrificial layer, forming openings in the insulating layer at positions of the sacrificial layer, exposing electrode components at corresponding positions.

S280 , modifying the surface of the electrode unit 3 .

That is, a layer of platinum black or iridium oxide is plated on the exposed surface of the electrode unit 3 as a modification layer to reduce impedance.

In other embodiments, the material of the modification layer can be platinum, iridium, or an alloy or compound containing one or both of these two elements, or polypyrrole, poly(3,4-ethylenedioxythiophene), poly(3,4-ethylenedioxythiophene), One of the polyanilines.

Example 2:

Fig. 5 is a schematic structural view of the flexible epicardial ECG electrode chip in Embodiment 2, the flexible epicardial ECG electrode chip is also composed of a flexible base 7, an insulating layer 8, an electrode unit 9, electrode leads 10 and lead connection points 115 Partial composition. The difference between this embodiment and the electrode structure in Embodiment 1 is that it adopts a stepped electrode structure, and the thickness of the flexible substrate 7 is designed in a stepped shape. Although polydimethylsiloxane itself has good elastic properties, its dynamic stretchability, softness and adhesion are still closely related to its thickness. In order to better adapt to the contraction and relaxation of the heart and avoid damage to the epicardium, the flexible substrate 7 at the position where the electrodes are attached to the heart (mainly concentrated in the electrode unit array and part of the routing area) can be thinned . Specifically, in one embodiment, the thickness of the flexible base 7 located below the electrode unit 9 is much smaller than the thickness of other regions of the flexible base 7 , which is generally less than one-tenth. In this embodiment, the flexible substrate 7 at the position where the electrode is attached to the heart is partially thinned to below 5 μm, while the peripheral lead connection point 11 can be kept at a thicker level of 50-500 μm, which can ensure The flexibility of the device also ensures its maneuverability during packaging and surgery.

In Embodiment 2, the thickness of the part of the flexible base 7 located below the lead connection point 11 is much greater than the thickness of the part of the flexible base 7 located below the electrode unit 9 and the electrode lead 10, and the side of the flexible base 7 provided with the electrode assembly is a plane . FIG. 6 is a cross-sectional view along the dotted line 12 shown in FIG. 5 . FIG. 7 is a schematic diagram of its application, which includes a heart 13 and a wire 14, which is used to realize the connection between the lead connection point 11 and the external circuit.

In Embodiment 2, the cross-section of the flexible substrate 7 is a rectangle, and the electrode units 9 correspond to the lead connection points 11 one by one. The electrode assembly includes two rows symmetrical about the vertical line of the rectangle, the electrode unit 9 and its corresponding lead connection point 11 are located on the same side of the vertical line, the electrode unit 9 is located near the vertical line, and the corresponding lead connection point 11 is located near the side of the rectangle parallel to the median. The middle part of the flexible epicardial ECG electrode chip forms an inward depression on the side facing away from the insulating layer 8 .

Provide a kind of preparation method of the flexible epicardial ECG electrode chip in embodiment 2 again, see Fig. 8, comprise the following steps:

S310, preparing a polydimethylsiloxane flexible substrate 7 with a step structure on the glass substrate with a convex structure.

In this embodiment, the boss structure is a right-angle boss, and in other embodiments, it may also be an oblique boss.

S320 , using a lift-off technique to prepare the required reverse photoresist pattern of the electrode unit 9 , electrode leads 10 and lead connection points 11 on the flexible substrate 7 .

S330, depositing a metal titanium film on the flexible substrate 7 by means of electron beam evaporation.

S340, removing the photoresist and the metal titanium film on it, and directly forming the required electrode units 9, electrode leads 10 and lead connection points 11.

S350, spin coating a layer of polydimethylsiloxane as the insulating layer 8 on the flexible substrate prepared with the electrode unit 9 , electrode leads 10 and lead connection points 11 .

S360, using a laser cutting method to cut corresponding positions of the electrode unit 9 and the lead wire connection point 11, and remove the insulating layer on the surface of the electrode unit 9 and the lead wire connection point 11 to realize an opening.

S370 , modifying the surface of the electrode unit 9 .

That is, a layer of platinum black or iridium oxide is plated on the exposed surface of the electrode unit 9 as a modification layer to reduce impedance.

As an electrode chip that accurately measures, observes and analyzes the electrical activity of the heart, the flexible epicardial ECG electrode chip is different from conventional ECG electrodes. It can not only diagnose macroscopically, but also determine the precise location of the lesion. It provides an objective basis for sex therapy, and can also observe the efficacy of drugs more intuitively.

Compared with the prior art, the present invention has the following beneficial effects:

1. The flexible epicardial ECG electrode chip is made of materials with good biocompatibility with living organisms and can be used in vivo for a long time.

2. The electrode chip is made of flexible materials, which can better adapt to different contours of the heart surface and can expand and contract synchronously with the heart movement without displacement.

3. The electrode chip is automatically attached, which avoids the damage potential caused by the suture on the myocardium and affects the accuracy of signal acquisition.

4. The connection point of the lead wire adopts a flexible design to ensure that each electrode point is in good contact with the epicardium, and avoids the phenomenon of on and off caused by rigid material electrode contacts.

5. The spatial resolution of the electrode chip can be changed according to the needs, the interference between the electrode arrays is small, it is easy to use, and no stitching is required.

6. The recording chip style applied to different parts can be designed according to the structure of the heart. It can be placed in many places, the dislocation rate is low, and there will be no complications.

7. The electrode chip still maintains good electrical properties under the conditions of folding, twisting and stretching, which improves the operability of implantation and reduces the risk of surgery.

8. This electrode chip can also be used to visually observe the efficacy of drugs.

The above-mentioned embodiments only express several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (10)

1. A flexible epicardial electrocardiogram electrode chip, is characterized in that, comprises: flexible substrate, electrode unit, electrode lead wire, lead wire connection point and insulating layer, described electrode unit, electrode lead wire and lead wire connection point form electrode assembly jointly , the electrode assembly is arranged on the flexible substrate, the electrode unit is connected to the lead connection point via the electrode lead to realize electrical connection, the insulating layer is arranged on the flexible substrate and covers the electrode lead, the The electrode unit is used to electrically connect the surface of the heart, and the material of the flexible base and the insulating layer is polydimethylsiloxane. 2 . The flexible epicardial ECG electrode chip according to claim 1 , wherein the electrode assembly includes an electrode layer, and the material of the electrode layer is one of gold, titanium, and copper. 3. flexible epicardial electrocardiogram electrode chip according to claim 2, it is characterized in that, described electrode assembly also comprises bottoming layer, and described electrode layer is arranged on described bottoming layer, and the material of described bottoming layer is Titanium, chromium, or alloys containing one or both of these elements. 4. according to claim 2 or 3 described flexible epicardial ECG electrode chip, it is characterized in that, described electrode unit also comprises modification layer, and described modification layer is arranged on the surface of electrode unit facing away from described flexible substrate, The material of the modification layer is platinum, iridium, or an alloy or compound containing one or two of these two elements, or one of polypyrrole, poly(3,4-ethylenedioxythiophene), and polyaniline. kind. 5 . The flexible epicardial ECG electrode chip according to claim 1 , wherein the thickness of the flexible substrate located at the electrode unit is much smaller than the thickness of other regions of the flexible substrate. 6 . 6. flexible epicardial ECG electrode chip according to claim 5, is characterized in that, the cross-section of described flexible substrate is rectangle, and described electrode unit and lead wire connection point correspond one by one, and described electrode assembly comprises about Two columns symmetrical to the vertical line of the rectangle, the electrode unit and the corresponding lead wire connection point are located on the same side of the vertical line, the electrode unit is located near the vertical line, and the corresponding lead wire connection point Located close to one side of the rectangle parallel to the mid-perpendicular line, the middle part of the flexible epicardial ECG electrode chip forms an inward depression on the side facing away from the insulating layer. 7. A preparation method for a flexible epicardial ECG electrode chip, comprising the following steps: Step 1, disposing polydimethylsiloxane on the rigid substrate to form a flexible substrate; Step 2, forming an electrode assembly on the flexible substrate, the electrode assembly including a lead connection point, an electrode unit for electrically connecting the surface of the heart, and an electrode lead electrically connecting the lead connection point and the electrode unit; Step 3, disposing polydimethylsiloxane covering the electrode assembly on the flexible substrate to form an insulating layer, and forming an opening at the connection point of the electrode unit and the lead wire of the insulating layer to expose the electrode unit and lead connection points; Step 4, separating the flexible substrate from the rigid substrate to obtain the flexible epicardial ECG electrode chip. 8. the preparation method of flexible epicardial ECG electrode chip according to claim 7, is characterized in that, described step 2 comprises: preparing a mask formed with a hollow pattern in the shape of the electrode assembly; closely attaching the mask to the flexible substrate; depositing a primer layer on the flexible substrate attached with the mask; Depositing a layer of electrode layer on the primer layer; The mask is removed from the flexible substrate. 9. the preparation method of flexible epicardial electrocardiogram electrode chip according to claim 7, is characterized in that, also comprises the step of coating a layer of modified layer on the surface of described electrode unit after described step 3, described modified layer The material is platinum, iridium, or an alloy or compound containing one or two of these two elements, or one of polypyrrole, poly(3,4-ethylenedioxythiophene), and polyaniline. 10. The method for preparing a flexible epicardial electrocardiogram electrode chip according to claim 7, wherein the rigid substrate is a glass boss.

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