Bipolar microelectrode for mapping bioelectric signals and method of making same

Abstract

This invention discloses a bipolar microelectrode for electrophysiological signal mapping in biological tissues and its preparation method, belonging to the field of bioelectrophysiological detection technology. The bipolar microelectrode comprises two electrode bodies, each including a probe electrode core and an electrode tail. The probe electrode core is composed of a tungsten wire core and a gold-plated layer, and is externally fitted with a glass tube to reduce noise interference. The electrode tail consists of a copper wire and an inner insulating layer. The bipolar microelectrode also includes an outer shielding layer, within which both electrode bodies are located, with a distance of 10-15 μm between their tips. The signal sensitivity of the bipolar microelectrode in this invention meets a maximum resolution of 30 μm. 2 It has a minimum identifiable signal voltage amplitude of 10uV and a certain degree of electromagnetic interference resistance. It can be used in conventional shielded environments. Moreover, the electrode structure is highly operable and can be used for repeated calibration.

Description

Technical Field

[0001] This invention relates to the field of bioelectrophysiological detection technology, and in particular to bipolar microelectrodes for mapping electrical signals in biological tissues and their preparation methods. Background Technology

[0002] Bioelectrical signals are a crucial component in maintaining biological activities and intercellular information exchange. The bioelectrical activity of cardiac tissue also plays a vital role in maintaining cardiac electrical conduction and mechanical coupling; abnormal changes can lead to cardiac rhythm disturbances or the development of arrhythmias. Identifying changes in electrical activity among cardiac tissues is a key means of understanding the mechanisms by which the heart maintains its physiological state and its pathological processes. Research on cardiac electrical signals has a history of over a century, from the earliest electrocardiograms recording the overall electrical activity of the heart, to patch technology recording cellular action potentials, and more recently, the application of high-density three-dimensional electrical mapping technology for the entire heart. The accuracy and throughput of bioelectrical signal detection have significantly improved. A deeper understanding and analysis of bioelectrical activity has further promoted the development of related drugs and improved the success rate of surgical treatment for clinical arrhythmias.

[0003] Currently applied bioelectric mapping techniques are mainly divided into intracellular mapping and extracellular mapping, depending on the research objective. Intracellular mapping is mainly achieved using patch-clamp techniques, which can record changes in cellular action potentials and the electrical activity of individual ion channels. It offers high precision but low throughput, often recording only the activity within a single cell, making it difficult to analyze the effects of electrical signals at the tissue level. Its main applications are in intracellular signal transduction analysis and drug toxicity to cellular ion channels. Extracellular mapping primarily targets tissue levels or whole organs, recording changes in extracellular potentials across different ranges depending on the electrode cross-section, enabling high-throughput recording. However, its current precision is lower, generally consisting of mixed potential signals from a swarm of cells (three-dimensional signals typically contain over a hundred cells). It is mainly used for intraoperative mapping in clinical electrophysiological surgery, integrating information from tens of thousands of points to study the overall electrical activity of tissues or organs. This technology has achieved a surgical intervention success rate of nearly 90% for clinical premature ventricular contractions, supraventricular tachycardia, and typical atrial tachycardia. However, progress in understanding the mechanisms of complex arrhythmias, such as scar atrial tachycardia, atrial fibrillation, and ventricular tachycardia, is difficult, mainly because the spatial resolution of extracellular electrical mapping is generally greater than 1 mm. This causes the recorded electrical signals to overlap due to the synchronous excitation of cellular electrical activity in time, making it impossible to distinguish the timing and direction of excitation in local space, thus limiting the analysis of conduction mechanisms.

[0004] Extracellular mapping is categorized into unipolar and bipolar mapping based on the content of the acquired signal. Unipolar mapping typically uses a 2-4mm high-conductivity metal probe tip, connected to a single-strand conductive wire encased in insulating, interference-resistant plastic, which then connects to a signal amplifier. It generally records the entire time-series electrical activity of the cell cycle. In two-dimensional mapping, the depth of the signal source can be indirectly determined by identifying the positive or negative sign of the recorded waveform. However, unipolar signals often incorporate more signals from the surrounding electrodes, resulting in lower accuracy for analyzing local signals. Bipolar mapping requires a dual-channel probe tip. The recorded electrical signal is related to the distance between the two probe tips, recording only the electrical signal between the electrodes. This shields signals outside the two probe tips, offering advantages in local signal analysis.

[0005] Therefore, further improving the accuracy of extracellular mapping electrodes is of great significance for understanding the overall performance of electrical signals under physiological conditions and for the diagnosis and treatment of complex clinical arrhythmias. By further reducing the probe tip of the monopolar electrode, the influence of ambient field potential on the target potential can be reduced without affecting signal integrity. However, this requires simultaneously improving the signal's anti-interference capability, because a smaller probe electrode will obtain a more precise target signal source, but its amplitude will be significantly reduced, potentially making it more susceptible to the influence of ambient electromagnetic fields. Simultaneously, the interaction between the microelectrode and the mapped tissue needs to be feasible; smaller probe tips are more prone to damage due to low operational tolerance. Generally, microelectrode recording is achieved using high-conductivity metal wires and glass electrodes filled with electrolyte. Metal-based microelectrodes are currently mostly used for tissue field potential mapping, with mapping accuracy ranges generally greater than 200 μm. Metal electrodes have better toughness and hardness, are highly maneuverable, and are suitable for high-throughput, large-scale, repetitive mapping, but their sensitivity is relatively low, making it difficult to identify signals from single cells or small cell populations. Meanwhile, metal electrodes have a larger exposed volume in contact with the environment, making them more susceptible to electromagnetic interference and resulting in higher background noise during calibration. Glass electrodes can be thermally drawn to achieve probe tips as small as μm, but they are more brittle and have lower maneuverability. They are generally only used for single calibration and cannot be reused. Furthermore, they typically require a dedicated patch-clamp amplifier for connection, resulting in poor versatility. Summary of the Invention

[0006] To address the aforementioned problems, this invention aims to provide a bipolar microelectrode for electrical signal mapping in biological tissues and its fabrication method. This bipolar microelectrode achieves a signal sensitivity meeting a maximum resolution of 30 μm. 2 It has a minimum identifiable signal voltage amplitude of 10uV and a certain degree of electromagnetic interference resistance. It can be used in conventional shielded environments. Moreover, the electrode structure is highly operable and can be used for repeated calibration.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A bipolar microelectrode for electrical signal mapping of biological tissues includes two electrode bodies, characterized in that: each electrode body includes a probe electrode core and an electrode tail end, wherein the probe electrode core and the electrode tail end are fixedly connected.

[0009] The bipolar microelectrode also includes an outer shielding layer, and both electrode bodies are located within the outer shielding layer.

[0010] Furthermore, the distance between the front ends of the two electrode bodies is 10-15 μm.

[0011] Furthermore, the inner core of the detection electrode includes a tungsten wire core, and a gold-plated layer is provided on the outer front end of the tungsten wire core. The tungsten wire core and the gold-plated layer form a composite metal control electrode. A glass tube is provided outside the composite metal control electrode. The rear end of the glass tube is fixedly connected to the tungsten wire core through a sealing block, and the rear end of the tungsten wire core passes through the sealing block. The front end of the composite metal control electrode passes through the glass tube.

[0012] Furthermore, the length of the front end of the composite metal control electrode penetrating the glass tube is <30µm.

[0013] Furthermore, the electrode tail end includes a copper wire, which is covered with an inner insulating layer, and both the front and rear ends of the copper wire penetrate the inner insulating layer. The rear end of the tungsten wire core is fixedly connected to the front end of the copper wire.

[0014] Furthermore, the rear end of the tungsten wire core is fixedly connected to the front end of the copper wire by welding a tin transition section.

[0015] Furthermore, the outer shielding layer comprises, from the inside out, a copper mesh layer, an aluminum foil layer, and an outer insulating layer, and the front end of the inner core of the detection electrode and the rear end of the electrode both penetrate the outer shielding layer.

[0016] Furthermore, a method for preparing a bipolar microelectrode for electrical signal mapping of biological tissues is characterized by comprising the following steps:

[0017] S1: Fabrication of two composite metal detection electrode cores;

[0018] S2: Prepare two electrode tail ends;

[0019] S3: Connect the inner core of each detection electrode to the corresponding motor tail end to assemble two electrode bodies;

[0020] S4: An outer shielding layer is used to wrap the two electrode bodies together, forming a bipolar microelectrode. The beneficial effect of this invention is that, compared with the prior art, the improvement of this invention lies in…

[0021] 1. This invention discloses a bipolar microelectrode for mapping electrical signals in biological tissues, comprising two electrode bodies, the distance between the front ends of the two electrode bodies being 10-15 μm, equivalent to a resolution of 2-5 cell orders, and the diameter of the front end of each electrode body being less than 10 μm, thereby making the contact cross section between the entire bipolar microelectrode and the mapped tissue less than 20 μm, enabling extracellular potential mapping at the level of a single myocardium cell.

[0022] 2. In this invention, the inner core of the detection electrode of the electrode body is formed by a tungsten wire core and a gold-plated layer to form a composite metal control electrode. A silicate-drawn glass tube is set outside the composite metal control electrode, which can reduce noise. The length of the front end of the composite metal control electrode penetrating the glass tube is <30µm, the diameter of the tungsten wire core is 10µm, and the thickness of the gold-plated layer is 0.3µm. Under the premise of reducing the contact cross-section with the measured tissue, the high conductivity material is used without increasing signal loss, and the minimum amplitude of the identified signal voltage is 10µV.

[0023] 3. Compared with existing metal micro-gauge electrodes, the bipolar microelectrode in this invention has higher signal sensitivity and a maximum resolution of 30 μm. 2 This allows for a better reduction of the influence of the surrounding tissue field potential on the target potential.

[0024] 4. In this invention, the rear end of the tungsten wire core in the inner core of the detection electrode is welded and fixedly connected to the front end of the copper wire in the tail end of the electrode through a tin transition section, which can achieve a stable connection between the 10µm diameter tungsten wire and the 0.5mm diameter copper wire; the outer shielding layer outside the electrode body can not only bear the electrode body, but also achieve continuous calibration controllability and good anti-electromagnetic interference capability, and the background noise of the recorded signal can be less than 10µV; moreover, the electrode body is small in size, has high electrode operability, can be repeatedly used and realize high-throughput calibration.

[0025] 5. The bipolar microelectrode in this invention can be used to detect high-resolution electrical signals from cardiac tissue, enabling stable unipolar recording and programmed stimulation recording. The high-resolution characteristics of the electrode allow for further exploration of physiological myocardial conduction characteristics, particularly in the atrioventricular junction, an anatomically complex region with multiple tissue junctions, where high-resolution signals are essential. In complex arrhythmias, it can be used to distinguish differences in myocardial cell conduction under various conditions, such as scar-related atrial flutter and ventricular tachycardia, which is of significant value in revealing the mechanisms of arrhythmias and improving electrophysiological surgical treatment protocols. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the bipolar microelectrode structure in this invention.

[0027] Figure 2 For the present invention Figure 1 Enlarged view of a portion of the structure in section A.

[0028] Figure 3 This is a schematic diagram of the electrode body structure in this invention.

[0029] Figure 4 This is a schematic diagram of the core structure of the probe electrode in this invention.

[0030] Figure 5 For the present invention Figure 4 Enlarged view of a portion of the structure in section B.

[0031] Figure 6 This is a schematic diagram of the application mode of the bipolar microelectrode in this invention.

[0032] Figure 7 In Example 2 of this invention, a bipolar microelectrode was used for right atrial ventilator mapping under aortic perfusion, and the size of the motor was compared with the size of the pathological slide.

[0033] Figure 8 This is the experimental result of the application of bipolar microelectrodes to map the atrioventricular junction region in Embodiment 2 of the present invention.

[0034] Figure 9 This is the experimental result of continuous mapping of the atrioventricular junction region using bipolar microelectrodes in Embodiment 2 of the present invention.

[0035] Figure 10 This invention relates to a third embodiment of the application of bipolar microelectrodes to record the myocardial potential in the scar area after myocardial infarction.

[0036] Among them: 1-tungsten wire core, 2-gold plating layer, 3-glass tube, 4-sealing block, 5-copper wire, 6-inner insulation layer, 7-tin transition section, 8-copper mesh layer, 9-aluminum foil layer, 10-outer insulation layer. Detailed Implementation

[0037] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0038] Example 1:

[0039] As attached Figure 1-5 As shown, a bipolar microelectrode for biotissue electrical signal mapping includes two electrode bodies, each of which includes a probe electrode core and an electrode tail end, the probe electrode core being fixedly connected to the electrode tail end; the bipolar microelectrode also includes an outer shielding layer, and both electrode bodies are located within the outer shielding layer.

[0040] Specifically, each electrode body includes a detection electrode core and an electrode tail end. The detection electrode core includes a tungsten wire core 1. A gold-plated layer 2 is provided on the outer front end of the tungsten wire core 1. The tungsten wire core 1 and the gold-plated layer 2 form a composite metal control electrode. A glass tube 3 is provided outside the composite metal control electrode. The rear end of the glass tube 3 is fixedly connected to the tungsten wire core 1 through a sealing block 4, and the rear end of the tungsten wire core 1 passes through the sealing block 4. The front end of the composite metal control electrode passes through the glass tube 3.

[0041] Preferably, the diameter of the tungsten wire core 1 is 10 μm, the thickness of the gold plating layer 2 is 0.3 μm, the glass tube 3 is made of silicate drawn glass tube, which can reduce noise, and the rear end of the glass tube 3 is provided with a cylindrical sealing block 4 made of ethyl cyanoacrylate material, the rear end of the tungsten wire core 1 passes through the sealing block 4 and is fixedly connected to the sealing block 4.

[0042] The length of the front end of the composite metal control electrode formed by the tungsten wire core 1 and the gold plating layer 2 penetrating the glass tube 3 is <30µm, that is, the exposed height of the probe end of the composite metal control electrode is <30µm. The distance between the front ends of the two composite metal control electrodes is 10-15µm. In order to ensure that the distance between the front ends of the two composite metal control electrodes is between 10-15µm, the tungsten wire core 1 of one of the electrode bodies can be bent. The electrode body corresponding to the bent tungsten wire core 1 can be noise-proofed and fixed by two sections of glass tube 3, thereby ensuring the stability of the electrode body during use.

[0043] The electrode tail end includes a copper wire 5, which is covered with an inner insulating layer 6. Both the front and rear ends of the copper wire 5 penetrate the inner insulating layer 6. The copper wire 5 is a low-resistance, malleable copper wire with a diameter of 0.5 mm.

[0044] The rear end of the tungsten wire core 1 in the inner core of the detection electrode is fixedly connected to the front end of the copper wire 5 in the electrode tail end by welding through a tin transition section 7, which can achieve a stable connection between the 10um diameter tungsten wire and the 0.5mm diameter copper wire. After the inner core of the detection electrode, the electrode tail end and the tin transition section 7 are fixedly connected, they form the electrode body structure.

[0045] The outer shielding layer comprises, from the inside out, a copper mesh layer 8, an aluminum foil layer 9, and an outer insulating layer 10. The front end of the inner core of the detection electrode and the rear end of the electrode both penetrate the outer shielding layer.

[0046] The method for preparing the bipolar microelectrode for electrical signal mapping of biological tissues in this invention includes the following steps:

[0047] S1: Fabrication of two composite metal detection electrode cores;

[0048] Two tungsten wire cores 1 are taken separately, and gold plating is performed on their front ends to form a gold plating layer 2. The tungsten wire cores 1 and the gold plating layer 2 together form a composite metal control electrode. Then, the composite metal control electrode is placed in a glass tube 3 made of silicate glass.

[0049] One of the tungsten wire cores 1 is bent and its corresponding glass tube 3 is broken off. Then, the front end of the broken glass tube 3 is attached to the glass tube 3 outside the other tungsten wire core 1. The distance between the front ends of the two composite metal control electrodes is kept between 10-15 μm.

[0050] S2: Prepare two electrode tail ends;

[0051] Take two copper wires 5 with a diameter of 0.5mm, wrap an inner insulation layer 6 around the copper wires 5, and both the front end and the rear end of the copper wires 5 penetrate the inner insulation layer 6. The copper wires 5 are low-resistance, malleable copper wires.

[0052] S3: Connect the inner core of each detection electrode to the corresponding motor tail end to assemble two electrode bodies;

[0053] By welding the tail end of the tungsten wire core 1 of each probe electrode core to the front end of the corresponding copper wire 5 through the tin transition section 7, a stable connection between the 10um diameter tungsten wire and the 0.5mm diameter copper wire can be achieved.

[0054] S4: Use an outer shielding layer to wrap the two electrode bodies together to form a bipolar microelectrode.

[0055] Example 2:

[0056] Example 2 applies the bipolar microelectrode from Example 1 to recording the atrioventricular node potential of an isolated heart. When using this bipolar microelectrode, it needs to be connected sequentially to an electrode coupler, a signal amplifier, and a digital-to-analog converter. A detailed application diagram is attached. Figure 6 As shown.

[0057] The specific application implementation process is as follows:

[0058] 1. Materials

[0059] 1.1 Animals

[0060] Adult New Zealand White Rabbit

[0061] 1.2 Reagents

[0062] Heparin (3125 U / kg), an anticoagulant for intraperitoneal injection.

[0063] 10% Chloral Hydrate for Anesthesia of Laboratory Animals

[0064] Continuous infusion with saturated gas (95% O2 + 5% CO2)

[0065] Modified perfusion solution for benchtop use (119mM NaCl, 25mM NaHCO3, 1.2mM NaH2PO4, 1.0mM MgSO4·6H2O, 4.0mM KCl, 1.8mM CaCl2, 10mM D-GlucoseH2O)

[0066] 1.3 Equipment

[0067] PC-100 glass electrode drawing instrument; 2 AM 1800 amplifiers; Digidata 1440B digital-to-analog converter;

[0068] 2. Methods

[0069] 2.1 Modified Langendorff isolated heart perfusion

[0070] Rabbits were intraperitoneally injected with heparin for anticoagulation (3125 U / kg). Fifteen minutes later, the animals were anesthetized with 10% chloral hydrate. After thoracotomy, the heart was removed and placed in a modified Tyrode buffer solution (119 mM NaCl, 25 mM NaHCO3, 1.2 mM NaH2PO4, 1.0 mM MgSO4·6H2O, 4.0 mM KCl, 1.8 mM CaCl2, 10 mM D-GlucoseH2O) saturated with gas (95% O2 + 5% CO2). Connective tissue and lung tissue were rapidly removed, leaving 3-5 mm of aorta. The aorta was cannulated and connected to a Langendorff perfusion system, and Tyrode's solution was pumped retrogradely through the aorta at a rate of 8-10 mL / min. The perfusion solution was kept at a constant temperature of 35 ± 1 °C and continuously oxygenated (95% O2 + 5% CO2) throughout the process.

[0071] 2.2 Fabrication of Bipolar Microelectrodes

[0072] The bipolar microelectrode was fabricated using the preparation method described in Example 1.

[0073] 2.3 Electrophysiological mapping in the atrioventricular junction

[0074] After the isolated heart was fixed to the Langendorff perfusion apparatus, the right atrium was cut open to expose the atrioventricular junction, and reference electrodes (HIS electrode, high right atrial electrode, and lateral Tudaro tendon electrode) and stimulation electrodes (atrial stimulation electrode and ventricular stimulation electrode) were placed. A dual-channel Axopatch 200B patch-clamp amplifier or an AM1800 multi-channel amplifier was connected, and a Digidata 1440B digital-to-analog converter was used for analog signal output. Micro-manipulation control was used to map the microelectrodes, and the target was continuously mapped. Up to three microelectrodes can be placed in the region of interest, and the conduction and transformation of the potential in the region of interest can be observed during programmed stimulation. Clampex 10 sampling software was used to monitor the field potential of all channels in real time.

[0075] 3. Results

[0076] (1) Appendix Figure 7 The image shows the application of bipolar microelectrodes for right atrial ventilator mapping under aortic perfusion.

[0077] (2) Appendix Figure 7 Image B shows a comparison of the size of the pathological section of the atrioventricular junction with the mapping electrode, indicating that the distance between the tips of the bipolar electrodes is approximately the size of two cells.

[0078] (3) Appendix Figure 8 The application of bipolar microelectrodes was used to map the atrioventricular junction region.

[0079] Recorded using Clampex software. (Attached) Figure 8 In the mid-A mode, under sinus rhythm, a relatively smooth bidirectional potential pattern is observed between the atrial and His potentials in the AVN channel, appearing with each beat. The reference electrode at the proximal HIS indicates the timing of His and A activation, proving that the AVN potential in the AVN channel mapping channel is not the atrial and HIS potential. Simultaneously, the mapping electrode is located within the KOCH triangle, suggesting it represents the AVN potential. It can be seen that due to the extremely narrow bipolar electrode spacing, compared to traditional HIS electrode channels, the amplitudes of the A and V waves are also very small, indicating that most far-field A and V waves are shielded, and the mapped A waves are mostly near-field A waves.

[0080] Appendix Figure 8 In the same sample shown in Figure B, when atrioventricular block occurs, the AVN potential in the AVN channel also drops off like the HIS and V potentials, proving that this potential is not a delayed atrial far-field potential, and its occurrence is coupled with the HIS potential.

[0081] (4) Appendix Figure 9 This shows the application of ultramicroelectrodes for continuous mapping of the atrioventricular junction region, where, from the attached Figure 9Figures A through C show the continuous change in AV node potential as the AV node is traced to different locations along its course (from near the atrial connection to near the HIS). It can be seen that as the mapping location moves further distally, the AV node potential gradually moves closer to the HIS.

[0082] Example 3:

[0083] Example 3 applies the bipolar microelectrode from Example 1 to record myocardial potentials in the scar area after myocardial infarction. The specific implementation process is as follows:

[0084] 1. Materials

[0085] 1.1 Animals

[0086] Mouse model of myocardial infarction after anterior descending artery ligation

[0087] 1.2 Reagents

[0088] Heparin (3125 U / kg), an anticoagulant for intraperitoneal injection.

[0089] 10% Chloral Hydrate for Anesthesia of Laboratory Animals

[0090] Continuous infusion with saturated gas (95% O2 + 5% CO2)

[0091] Modified perfusion solution for benchtop use (119mM NaCl, 25mM NaHCO3, 1.2mM NaH2PO4, 1.0mM MgSO4·6H2O, 4.0mM KCl, 1.8mM CaCl2, 10mM D-GlucoseH2O)

[0092] 1.3 Equipment

[0093] PC-100 glass electrode drawing instrument; 2 AM 1800 amplifiers; Digidata 1440B digital-to-analog converter;

[0094] 2. Methods

[0095] 2.1 Modified Langendorff isolated heart perfusion

[0096] Mice were intraperitoneally injected with heparin for anticoagulation (3125 U / kg). Fifteen minutes later, the animals were anesthetized with 10% chloral hydrate. After thoracotomy, the heart was removed and placed in a modified Tyrode buffer solution (119 mM NaCl, 25 mM NaHCO3, 1.2 mM NaH2PO4, 1.0 mM MgSO4·6H2O, 4.0 mM KCl, 1.8 mM CaCl2, 10 mM D-GlucoseH2O) saturated with gas (95% O2 + 5% CO2). Connective tissue and lung tissue were rapidly removed, leaving 3-5 mm of aorta. The aorta was cannulated and connected to a Langendorff perfusion system, and Tyrode's solution was pumped retrogradely through the aorta at a rate of 8-10 mL / min. The perfusion solution was kept at a constant temperature of 35 ± 1 °C and continuously oxygenated (95% O2 + 5% CO2) throughout the process.

[0097] 2.2 Electrophysiological mapping of tissues surrounding myocardial infarction

[0098] After the ex vivo heart was fixed to the Langendorff perfusion apparatus, the infarct area was exposed, and reference electrodes and mapping electrodes (electrodes of healthy tissue adjacent to the infarct area, electrodes around the infarct area, and electrodes within the infarct area) were placed. Stimulation electrodes (atrial and ventricular stimulation electrodes) were placed as needed. A dual-channel Axopatch 200B patch-clamp amplifier or an AM1800 multi-channel amplifier was connected, and a Digidata 1440B digital-to-analog converter was used for analog signal output. Micromanipulation control was applied to continuously map the target using the mapping microelectrodes. Clampex 10 sampling software was used to monitor the field potential of all channels in real time.

[0099] 3 Results

[0100] The experimental results of this embodiment are attached. Figure 10 As shown, where

[0101] (1) Appendix Figure 10 Image A shows myocardial mapping in mice after myocardial infarction under aortic perfusion using the bipolar microelectrode of the present invention.

[0102] (2) Appendix Figure 10 Figure B shows the application of the bipolar microelectrode of this invention to map the transition zone of ventricular infarction.

[0103] Recording was performed using Clampex software. The results show that under sinus rhythm, the reference electrode is located in the normal ventricular myocardium region, and the mapping electrode is located in the ventricular infarction transition zone. Complex ventricular excitation potentials are visible in the ventricular infarction transition zone.

[0104] (3) Appendix Figure 10 C shows the application of the bipolar microelectrode of this invention to map the ventricular infarction area.

[0105] Recording was performed using Clampex software. The results show that under sinus rhythm, the reference electrode was located in the normal ventricular myocardium region, and the mapping electrode was located in the ventricular infarction scar region. High-frequency, low-amplitude fragmented potentials of ventricular excitation were visible in the scar region.

[0106] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A bipolar microelectrode for electrical signal mapping of cardiac tissue, comprising two electrode bodies, characterized in that: Each of the electrode bodies includes a detection electrode core and an electrode tail end, wherein the detection electrode core is fixedly connected to the electrode tail end; The bipolar microelectrode also includes an outer shielding layer, and both electrode bodies are located within the outer shielding layer; The distance between the front ends of the two electrode bodies is 10-15 μm; The detection electrode core includes a tungsten wire core, and a gold-plated layer is provided on the front end of the tungsten wire core. The tungsten wire core and the gold-plated layer form a composite metal control electrode. A glass tube is provided outside the composite metal control electrode. The rear end of the glass tube is fixedly connected to the tungsten wire core through a sealing block, and the rear end of the tungsten wire core passes through the sealing block. The length of the front end of the composite metal control electrode passing through the glass tube is <30 μm. The electrode tail end includes a copper wire, and the rear end of the tungsten wire core is fixedly connected to the front end of the copper wire by a tin transition section.

2. The bipolar microelectrode for electrical signal mapping of cardiac tissue according to claim 1, characterized in that: The copper wire is covered with an inner insulation layer, and both the front and rear ends of the copper wire penetrate the inner insulation layer.

3. The bipolar microelectrode for electrical signal mapping of cardiac tissue according to claim 2, characterized in that, The outer shielding layer comprises, from the inside out, a copper mesh layer, an aluminum foil layer, and an outer insulating layer. The front end of the inner core of the detection electrode and the rear end of the electrode both penetrate the outer shielding layer.

4. The method for preparing a bipolar microelectrode for electrical signal mapping of cardiac tissue as described in any one of claims 1-3, characterized in that, Includes the following steps, S1: Fabrication of two composite metal detection electrode cores; S2: Prepare two electrode tail ends; S3: Connect the inner core of each detection electrode to the corresponding motor tail end to assemble two electrode bodies; S4: Use an outer shielding layer to wrap the two electrode bodies together to form a bipolar microelectrode.

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