A non-full-circumference petal-shaped pulsed electric field ablation electrode head

Abstract

This invention belongs to the field of cardiovascular interventional medical device technology and discloses a non-circumferential petal-shaped pulsed electric field ablation electrode head, including a flexible electrode assembly, several conductive leads, positioning marks, and a control mechanism. The flexible electrode assembly includes several petal-shaped electrodes centrally arranged on one side of the axial direction of the ablation catheter body. Each petal-shaped electrode includes a flexible base on the inner side and a conductive electrode layer on the outer side. The conductive electrode layer of each petal-shaped electrode is connected to an independent conductive lead. Each conductive lead extends along the inner lumen of the ablation catheter body to the proximal interface of the catheter. Positioning marks are respectively set on the outer sides of both ends of the distribution range of the petal-shaped electrodes along the axial direction of the ablation catheter body. The control mechanism is set at one end of the ablation catheter body and connected to each petal-shaped electrode. Each petal-shaped electrode of this invention can passively conform to the anatomical contour of the coronary artery diameter and adaptively abut against the target tissue, while maintaining continuous unobstructed coronary blood flow during the ablation operation.

Description

Technical Field

[0001] This invention relates to the field of cardiovascular interventional medical device technology, specifically to a non-circumferential petal-shaped pulsed electric field ablation electrode head. Background Technology

[0002] Myocardial bridging is a common congenital coronary artery anatomical abnormality, where a segment of a coronary artery is covered by myocardial fibers. During cardiac systole, this segment of the coronary artery is compressed by the myocardium, resulting in luminal narrowing. Its incidence in the population is approximately 15%–85%, with about 70%–80% being superficial types with a bridge thickness of 0–3 mm. It can lead to ischemic chest pain, decreased exercise tolerance, and even myocardial infarction. Pulsed electric field ablation (PFA) technology, due to its tissue selectivity and non-thermal invasiveness, offers new possibilities for the minimally invasive treatment of myocardial bridging.

[0003] Chinese invention application No. 202110178247.2 discloses a pulsed electric field ablation device and its usage method, specifically including an arc-shaped terminal tube and multiple ablation electrodes arranged along the surface of the arc-shaped body. In use, the arc-shaped terminal tube is delivered as a whole to the myocardial bridging region, and circumferential ablation of the target tissue is achieved through electrode discharge. However, this prior art has the following problems: First, its electrodes are integrated into the arc-shaped terminal tube, which is a fixed curved structure of the tube rather than an independently movable petal-shaped electrode design. Therefore, the relative position and contact angle of each electrode cannot be independently adjusted according to the anatomical morphology of the coronary artery diameter, making it difficult to ensure that each pair of electrodes can form a stable and sufficient effective contact with the tissue, easily causing ablation gaps or repeated damage; Second, during ablation, the curved part of this fixed arc-shaped structure will physically compress or block coronary blood flow, and it does not involve a non-circumferential contact design, making it impossible to maintain continuous unobstructed coronary blood flow during ablation, posing a potential risk of increased myocardial ischemia.

[0004] Therefore, the existing technology has problems such as the ablation electrode not being able to be independently adjusted according to the anatomical shape of the coronary artery diameter, and the fixed arc structure easily compressing coronary blood flow, thus affecting the smoothness of blood flow during the operation. These problems urgently need to be solved. Summary of the Invention

[0005] The purpose of this invention is to provide a non-circumferential petal-shaped pulsed electric field ablation electrode head to overcome the problems existing in the prior art. This invention enables each petal-shaped electrode to passively conform to the anatomical contour of the coronary artery diameter and adaptively adhere to the target tissue. At the same time, by concentrating the petal-shaped electrodes in the axial unilateral region of the catheter, the area of ​​the catheter wall not covered by the petal-shaped electrodes in the unfolded state and the gaps between each adjacent petal-shaped electrode together form a liquid channel, which can maintain continuous unobstructed coronary blood flow during the ablation operation.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a non-full-circumference petal-shaped pulsed electric field ablation electrode head, disposed at the end of the ablation catheter body, comprising: The flexible electrode assembly includes several petal-shaped electrodes centrally arranged in the axial unilateral region of the ablation catheter body. Each petal-shaped electrode includes a flexible substrate located on the inner side and a conductive electrode layer located on the outer side. The flexible substrate is used to drive the petal-shaped electrode from a retracted state to an unfolded state under its own elastic restoring force. In the unfolded state, the tube wall area not covered by the petal-shaped electrode and the gap between each adjacent petal-shaped electrode together form a liquid channel. Several conductive leads are provided, and the conductive electrode layer of each petal-shaped electrode is connected to an independent conductive lead. Each conductive lead extends along the inner lumen of the ablation catheter body to the proximal interface of the catheter. Positioning marks are set on the outer sides of both ends of the petal-shaped electrode along the axial distribution range of the ablation catheter body, respectively, to confirm the position and / or orientation of the electrode head under imaging; The control mechanism is located at one end of the ablation catheter body and is connected to each petal-shaped electrode. It is used to drive each petal-shaped electrode to switch between a closed state and an open state.

[0007] According to one embodiment of the present invention, in the retracted state, each petal-shaped electrode retracts and adheres to the outer surface of the ablation catheter body along the axial direction of the ablation catheter body; in the unfolded state, each petal-shaped electrode unfolds in an arc shape toward one side of the ablation catheter body by the elastic restoring force of the flexible substrate.

[0008] According to one embodiment of the present invention, a traction wire is disposed inside the ablation catheter body, one end of the traction wire is connected to each petal-shaped electrode, and the other end of the traction wire is connected to a control mechanism.

[0009] According to one embodiment of the present invention, the control mechanism is a push-pull handle or a spiral knob, used to drive the traction wire to move along the axial direction of the ablation catheter body, thereby causing each petal-shaped electrode to switch between a retracted state and an expanded state.

[0010] According to one embodiment of the present invention, the number of petal-shaped electrodes is 3 to 5, employing 3 to 5 independent, physically separated arc-shaped petal-shaped electrodes, concentrated in a single-sided area of ​​the catheter, forming a non-full circumferential coverage structure after deployment. This structure is the core design feature that distinguishes the present invention from existing full-circumferential ring or balloon electrodes, ensuring that after deployment within the coronary artery lumen, the electrode only occupies a portion of the circumferential area of ​​the vessel wall, automatically forming a blood flow channel on the opposite side. The circumferential gap angle between adjacent petal-shaped electrodes is 15° to 30°, and the axial spacing is 1 to 2 mm.

[0011] According to one embodiment of the present invention, there is no physical connection between the petal-shaped electrodes (non-continuous ring, non-fixed tubular arc shape). Each petal-shaped electrode is connected to the proximal end of the catheter via an independent conductive lead, supporting independent on / off switching, independent polarity configuration, and independent energy output. The physical separation refers to the fact that after unfolding, each petal-shaped electrode is separated from each other by a blood flow channel or circumferential gap. The petal-shaped electrode itself is an independent structural unit that can be replaced or deformed independently.

[0012] According to one embodiment of the present invention, the flexible substrate is a silicone substrate with a thickness of 0.08–0.15 mm and a self-elastic support force of ≤5 g; the thickness of the conductive electrode layer is 5–20 μm. By using an ultra-thin flexible silicone substrate (0.08–0.15 mm) to mount the conductive electrode layer, with a support force ≤5 g, which is lower than the safe threshold of the vascular intima (approximately 20 g), adaptive adhesion without airbag assistance or additional expansion force source is achieved, fundamentally eliminating the risk of mechanical compression-induced vascular injury.

[0013] According to one embodiment of the present invention, the flexible substrate is a butterfly-shaped or willow-leaf-shaped sheet.

[0014] According to one embodiment of the present invention, the surface of the petal-shaped electrode is further provided with a heparin covalent graft coating or a phosphocholine biomimetic coating, wherein the thickness of the heparin covalent graft coating is 2-3 μm and the thickness of the phosphocholine biomimetic coating is 3-5 μm.

[0015] According to one embodiment of the present invention, the positioning mark is an X-ray-proof metal imaging ring, the wall thickness of the metal imaging ring is 0.03 to 0.06 mm, the length of the metal imaging ring is 1.0 to 2.5 mm, and the distance between two metal imaging rings is 15 to 25 mm.

[0016] According to one embodiment of the present invention, the end of the ablation catheter body is further provided with an electrocardiogram synchronization signal interface, which includes at least two electrocardiogram signal input terminals for connecting an external electrocardiogram monitoring device.

[0017] The above technical solution has the following advantages or beneficial effects: This invention provides a non-circumferential petal-shaped pulsed electric field ablation electrode head, employing multiple independently arranged petal-shaped electrodes. Each petal-shaped electrode is independently driven to unfold by a flexible substrate under its own elastic restoring force, allowing each petal-shaped electrode to passively conform to the anatomical contour of the coronary artery diameter and adaptively adhere to the target tissue. This achieves full and stable adhesion between each pair of electrodes and the target tissue, effectively avoiding ablation gaps or repeated damage, and significantly improving the uniformity and effectiveness of ablation. Simultaneously, the non-circumferential adhesion design of this invention concentrates the petal-shaped electrodes on one side of the catheter axis. The area of ​​the catheter wall not covered by the petal-shaped electrodes in the unfolded state, along with the gaps between adjacent petal-shaped electrodes, together form a liquid channel, ensuring continuous unobstructed coronary blood flow throughout the ablation process. This avoids the physical compression or obstruction of blood flow by fixed arc-shaped structures, reducing the risk of myocardial ischemia. Furthermore, each petal-shaped electrode is connected to the proximal catheter interface by an independent conductive lead, enabling independent discharge control. This provides clinicians with a flexible and adjustable ablation strategy, further improving the safety and operational flexibility of the procedure. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the non-full-circumference petal-shaped pulsed electric field ablation electrode head shown in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the structure of the non-full-circumference petal-shaped pulsed electric field ablation electrode head shown in Embodiment 3 of the present invention; Figure 3 This is a side view of the non-full-circumference petal-shaped pulsed electric field ablation electrode head shown in Embodiment 3 of the present invention; Figure 4 This is a schematic diagram of the longitudinal cross-section of the electrode head of the present invention within a coronary myocardial bridging segment; Figure 5 This is an exploded schematic diagram of the layered structure of the single petal-shaped electrode of the present invention; In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1. Ablation catheter body; 2. Petal-shaped electrode; 3. Flexible substrate; 4. Conductive electrode layer; 5. Myocardial bridge; 6. Positioning marker; 7. Coronary artery wall. Detailed Implementation

[0019] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0020] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Among existing treatments for myocardial bridging, conservative drug therapy can only relieve symptoms, while open-chest release surgery is highly invasive and carries a high risk of complications. Pulsed electric field ablation (PFA) technology, due to its tissue selectivity and non-thermal damage characteristics, offers new possibilities for minimally invasive treatment of myocardial bridging.

[0026] Currently used pulsed electric field ablation catheter electrodes are mostly circumferential ring electrodes or balloon electrodes. When these electrodes are deployed within the coronary artery lumen, they have the following significant drawbacks: **Vascular occlusion:** After deployment, the circumferential ring electrode completely occupies the entire circumference of the vessel, completely blocking coronary blood flow and increasing the risk of acute myocardial ischemia. The coronary artery is the only blood supply artery to the myocardium; interruption of blood flow for even a few minutes during the procedure can cause irreversible myocardial damage. **Difficulty in targeted ablation:** The circumferential ring electrode uniformly releases a pulsed electric field throughout the entire circumference of the vessel wall, making it impossible to achieve targeted ablation of the eccentric direction where the myocardial bridge is located, resulting in unnecessary exposure of the normal vessel wall in non-target areas to the electric field. **Lack of independent petal-shaped electrodes:** Existing electrodes are mostly fixed arc-shaped tubes or continuous rings, with each electrode unit physically connected and not independently controllable. When facing asymmetric or eccentric myocardial bridges, it is impossible to implement targeted discharge and dynamic polarity configuration of independent petals. Insufficient balance between fit and blood flow: Full-circumferential structures either sacrifice blood flow to achieve full fit or reduce electrode size, resulting in insufficient fit, making it impossible to simultaneously ensure stable fit and unobstructed blood flow. Chinese invention application No. 2021101782472 discloses a pulsed electric field ablation device and its method of use, including an arc-shaped end tube and electrodes arranged along the arc. However, the electrodes of this device are integrated into the arc-shaped end tube, which is a fixed, curved structure of the tube rather than an independent petal-shaped design; it does not address non-full-circumferential fit solutions; it does not address the technical solution for separately controlling the independent petal-shaped electrodes; and it cannot maintain unobstructed coronary blood flow during ablation.

[0027] Therefore, there is an urgent need for a new type of electrode head structure that can be deployed in the coronary artery lumen without full circumference, ensuring stable contact between the electrode and the inner wall of the blood vessel while preserving the blood flow channel.

[0028] This invention provides a non-circumferential petal-shaped pulsed electric field ablation electrode tip, disposed at the end of the ablation catheter body 1, to solve the technical problems of existing pulsed electric field ablation electrode tips that block blood flow, cannot perform directional ablation, and lack independent petal control when deployed in the coronary artery lumen. While ensuring stable adhesion between the electrode and the vessel wall, it preserves sufficient coronary blood flow channels, achieving safe and precise intraluminal pulsed electric field ablation. It includes a flexible electrode assembly, several conductive leads, positioning markers 6, and a control mechanism for performing pulsed electric field ablation operations within the coronary artery lumen; the flexible electrode assembly includes several petal-shaped electrodes 2 centrally arranged in the axial unilateral region of the ablation catheter body 1, see [link to relevant documentation]. Figure 5Each petal-shaped electrode 2 includes an inner flexible substrate 3 and an outer conductive electrode layer 4. The flexible substrate 3 is used to drive the petal-shaped electrode 2 from a retracted state to an expanded state under its own elastic restoring force. In the expanded state, the tube wall area not covered by the petal-shaped electrode 2 and the gap between each adjacent petal-shaped electrode 2 together form a liquid channel. The conductive electrode layer 4 of each petal-shaped electrode 2 is connected to an independent conductive lead. Each conductive lead extends along the inner lumen of the ablation catheter body 1 to the proximal interface of the catheter. Positioning marks 6 are respectively set on the outer sides of both ends of the petal-shaped electrode 2 along the axial distribution range of the ablation catheter body 1, and are used to confirm the position and / or orientation of the electrode head under imaging. The control mechanism is set at one end of the ablation catheter body 1 and connected to each petal-shaped electrode 2, and is used to drive each petal-shaped electrode 2 to switch between the retracted state and the expanded state.

[0029] The petal-shaped electrodes 2 of this invention are concentrated on one side of the axial region of the catheter body. In the unfolded state, they only cover part of the circumferential wall of the catheter. The opposite wall region and the gaps between adjacent petal-shaped electrodes 2 together form a blood flow channel, ensuring uninterrupted coronary blood flow throughout the ablation process and completely eliminating the risk of acute myocardial ischemia caused by the full-circumferential ring electrode. Each petal-shaped electrode 2 is physically separated and connected to an independent conductive lead, which can independently control the on / off state, polarity, and energy output of each petal-shaped electrode 2, realizing directional electric field construction and precise targeted ablation of eccentric myocardial bridges, minimizing the exposure of the electric field to the non-target area of ​​the catheter wall. The ultra-thin flexible silicone substrate has extremely low self-elastic support force, which can adaptively conform to the inner wall of the blood vessel without the assistance of an airbag. The pressure of the adhesion is far below the safe threshold for damage to the vascular intima, avoiding mechanical compression damage to the intima.

[0030] It should be noted that the non-full-circumference petal-shaped pulsed electric field ablation electrode head described in this application can also be abbreviated as electrode head. For the sake of brevity, it will not be described separately thereafter.

[0031] Example 1: This embodiment provides a non-full-circumference petal-shaped pulsed electric field ablation electrode head, specifically a standard three-lobed electrode head, adapted to coronary arteries with a reference diameter of 2.8mm to 3.2mm. In this embodiment, the standard three-lobed electrode head is disposed at the distal end of the ablation catheter body 1, including a flexible electrode assembly, several conductive leads, positioning marks 6, and a control mechanism, for performing pulsed electric field ablation operations within the lumen of the coronary artery.

[0032] Preferably, the ablation catheter body 1 is a slender tubular structure, with its distal end used to install the non-full-circumference petal-shaped pulsed electric field ablation electrode head of this embodiment, and its proximal end used to connect the handle and external equipment. The ablation catheter body 1 has an axial inner cavity for accommodating components such as conductive leads and traction wires. One end of the traction wire is connected to each petal-shaped electrode 2, and the other end of the traction wire is connected to the control mechanism.

[0033] Preferred, see Figure 1 The flexible electrode assembly includes three independent petal-shaped electrodes 2, namely petal-shaped electrode 2a, petal-shaped electrode 2b, and petal-shaped electrode 2c. Each petal-shaped electrode 2 is structurally independent and physically separated from each other, and is centrally arranged on the same side of the ablation catheter body 1 along its axial direction (i.e., within a fan-shaped area of ​​0° to 180° of the catheter cross-section). This non-full-circumference centralized arrangement is one of the core features of this embodiment. Each petal-shaped electrode 2 includes a flexible substrate 3 on the inner side and a conductive electrode layer 4 on the outer side.

[0034] Preferably, the flexible substrate 3 is a willow-leaf shaped thin sheet made of medical-grade ultrathin flexible silicone. The flexible substrate 3 has a length of 8mm to 12mm, a width of 2.5mm to 3.5mm, and a thickness of 0.08mm to 0.15mm. In this embodiment, the thickness of the flexible substrate 3 is preferably 0.10mm. The flexible substrate 3 has a self-elastic support force ≤5g, enabling it to adaptively adhere to the inner wall of the blood vessel without the need for an external expansion force source, with the adhesion pressure far below the safe threshold for vascular intima damage (approximately 20g), achieving non-invasive adhesion.

[0035] Preferably, the flexible substrate 3 is used to drive the petal-shaped electrode 2 from a closed state to an unfolded state under its own elastic restoring force.

[0036] Preferably, the conductive electrode layer 4 is disposed on the outer surface of the flexible substrate 3, and is made of platinum-iridium alloy, formed on the outer arc surface of the silicone substrate by sputtering deposition. The thickness of the conductive electrode layer 4 is 5μm to 20μm, and is preferably 10μm in this embodiment. The conductive electrode layer 4 can maintain conductive continuity when the silicone substrate deforms.

[0037] Preferably, each petal-shaped electrode 2 is arranged on the same side along the axial direction of the ablation catheter body 1, with a circumferential gap angle of 15° to 30° between adjacent petal-shaped electrodes 2 and an axial spacing of 1 to 2 mm. In this embodiment, three petal-shaped electrodes 2 cover approximately 170° (about 1 / 2 circumference) of the coronary artery wall 7, forming a blood flow channel in an area of ​​approximately 190° on the opposite side. In the unfolded state, the area of ​​the vessel wall not covered by the petal-shaped electrodes 2 and the gaps between adjacent petal-shaped electrodes 2 together constitute a liquid channel. This liquid channel, i.e., the blood flow channel, is C-shaped or crescent-shaped, with an equivalent cross-sectional area not less than 30% of the cross-sectional area of ​​the coronary artery lumen where the electrode tip is located, ensuring uninterrupted and unobstructed coronary blood flow throughout the ablation process.

[0038] Preferably, several conductive leads are connected to each petal-shaped electrode 2. One end of each conductive lead is electrically connected to the conductive electrode layer 4 of the corresponding petal-shaped electrode 2, and the other end extends independently along the inner lumen of the ablation catheter body 1 to the interface at the proximal end of the catheter. Each conductive lead is wrapped with an insulating layer, and the conductive leads are mutually insulated, supporting independent on / off switching, independent polarity configuration, and independent energy output control of each petal-shaped electrode 2 to achieve electrical isolation between them. Through the independent lead design, the external system can apply voltage to each petal-shaped electrode 2 individually, independently control its on / off switching, independently configure its polarity, and independently output energy, thereby constructing an asymmetric, directional electric field distribution.

[0039] Preferably, the positioning mark 6 is located near the petal-shaped electrode 2 assembly. Specifically, the positioning mark 6 is located on the outer sides of both ends of the axial distribution range of the petal-shaped electrode 2 along the ablation catheter body 1, i.e., one is located at the proximal end of the petal-shaped electrode 2 array, and the other is located at the distal end. The positioning mark 6 is a radiopaque metal ring, made of platinum-iridium alloy or tantalum. The wall thickness of the metal ring is 0.03mm to 0.06mm, preferably 0.05mm in this embodiment; the length is 1.0mm to 2.5mm, and the outer diameter is flush with the ablation catheter body 1. The distance between the two metal rings is 15mm to 25mm, preferably 18mm in this embodiment. Under X-ray fluoroscopy, these two rings can clearly mark the working segment of the electrode tip, helping the operator to accurately confirm the axial position and circumferential orientation of the electrode tip, ensuring that the petal-shaped electrode 2 is aligned with the side wall of the myocardial bridge 5.

[0040] Preferably, the control mechanism is located at the proximal end of the ablation catheter body 1. A traction wire is disposed inside the ablation catheter body 1. One end of the traction wire is connected to each petal-shaped electrode 2, and the other end extends proximally along the inner cavity of the ablation catheter body 1, ultimately connecting to the control mechanism. The control mechanism is a push-pull handle used to drive the traction wire to move axially along the ablation catheter body 1, thereby causing each petal-shaped electrode 2 to switch between a retracted and extended state. By pushing and pulling, the operator transmits force to the distal end of the electrode head through the traction wire, overcoming or releasing the elastic force of the flexible substrate 3, thus realizing the retraction or extension of the petal-shaped electrodes 2.

[0041] Preferably, the non-circumferential petal-shaped pulsed electric field ablation electrode head described in this embodiment has two working states. In the retracted state, each petal-shaped electrode 2 retracts along the axial direction of the ablation catheter body 1 and is tightly attached to the outer surface of the ablation catheter body 1. At this time, the outer contour of the entire electrode head is streamlined, and its maximum outer diameter is ≤1.5mm. In this embodiment, the retracted outer diameter is 1.42mm, allowing the electrode head to pass smoothly through a standard 6F arterial sheath. The flexible base 3 is in a compressed or bent energy storage state. In the unfolded state, each petal-shaped electrode 2, driven by the elastic recovery force of the flexible base 3 itself, unfolds in an arc shape to one side of the ablation catheter body 1, forming a petal-shaped structure. After unfolding, the nominal working diameter of the electrode head is 3.0mm, adaptively matching the coronary artery diameter. The elastic deformation of the flexible base 3 decreases, and its outer conductive electrode layer 4 is pushed towards the coronary artery wall 7, achieving adhesion to the target area wall.

[0042] Preferably, the surface of the petal-shaped electrode 2 is further provided with an antithrombotic coating, specifically a heparin covalently grafted coating. The preparation process is as follows: first, a silicone substrate is treated with oxygen plasma to introduce active hydroxyl groups; then, low molecular weight heparin (molecular weight 4000–6000 Da) is formed into a monolayer on the surface of the petal-shaped electrode 2 through end-group activation and covalent bonding. The thickness of this heparin covalently grafted coating is 2 μm–3 μm, preferably 2.5 μm in this embodiment, covering the entire outer surface of the petal-shaped electrode 2. The thickness of this antithrombotic coating does not affect the macroscopic dimensions of the petal-shaped electrode 2, does not block pulsed current transmission, and can effectively inhibit contact coagulation activation and mural thrombus formation, extending the safe intracoronary operation time to more than 60 minutes.

[0043] Preferably, the proximal end of the ablation catheter body 1 is also provided with an electrocardiogram (ECG) synchronization signal interface. This interface includes at least two ECG signal input terminals for connecting external ECG monitoring equipment. This interface sends the surface ECG signal to the ablation control host after filtering and amplification. The host identifies the R wave and triggers pulse discharge during diastole (400ms to 600ms after the R wave) based on the R wave, thereby achieving ECG-synchronized ablation.

[0044] Preferably, a depth-limiting energy adjustment module can be integrated into the proximal end of the electrode tip or within the catheter handle. This module includes three hardware sub-circuits, all implemented purely in hardware and independent of software judgment. First, a hardware lockout circuit limits the output voltage amplitude to ensure that the inter-electrode field strength does not exceed 850V / cm. Second, an energy accumulation monitoring circuit integrates the total energy of a single-point output in real time, automatically stopping the output when the single-point accumulation reaches 18J. Third, an impedance monitoring circuit detects the load impedance in real time, stopping the discharge and issuing an alarm signal when the impedance exceeds the preset safety range (50Ω~200Ω). The above three hardware protection circuits work together to form a closed safety boundary for field strength, energy, and impedance. Output is automatically stopped when any parameter exceeds the limit, ensuring that hardware-level protection remains effective even in extreme cases of software failure or system crash. It should be noted that, without the depth-limiting energy adjustment module, the non-full-circumference petal-shaped pulse electric field ablation electrode tip of this embodiment can also achieve the technical problem to be solved by this application.

[0045] The non-full-circumference and physically separated structure of the petal-shaped electrode 2 naturally forms a blood flow channel, eliminating the need for additional independent perfusion tubing or bypass mechanisms. The equivalent cross-sectional area of ​​the blood flow channel is ≥30% of the lumen cross-sectional area, ensuring uninterrupted coronary blood flow throughout the ablation process. This structure organically integrates ablation and blood flow protection functions within the electrode tip's own shape.

[0046] Example 2: This embodiment provides a non-full-circumference petal-shaped pulsed electric field ablation electrode head, which differs from Embodiment 1 in that it adopts a four-petal structure, and further explains the different types of coatings used for antithrombosis and the alternative materials for the conductive electrode layer 4.

[0047] The non-circumferential petal-shaped pulsed electric field ablation electrode head of this embodiment includes four independent petal-shaped electrodes, namely petal electrode 2a, petal electrode 2b, petal electrode 2c, and petal electrode 2d. The four petal-shaped electrodes 2 are evenly spaced within a fan-shaped area of ​​approximately 200° on one side of the catheter body 1, covering approximately 200° (approximately 5 / 9 circumference) of the coronary artery wall 7. The area on the opposite side (approximately 160°) and the gaps between the valves form a blood flow channel. The flexible base 3 of each petal-shaped electrode 2 is a butterfly-shaped silicone base with a thickness of 0.08mm to 0.15mm, preferably 0.12mm in this embodiment, and has a self-elastic support force of approximately 4g.

[0048] Preferably, the conductive electrode layer 4 is disposed on the outer surface of the flexible substrate 3, and its material is a conductive silicone composite material. Specifically, the conductive silicone composite material is a silver nanowire-silicone composite material, which is formed on the outer surface of the silicone substrate by screen printing. The thickness of the conductive electrode layer 4 is 5μm to 20μm, and is preferably 15μm in this embodiment. This material exhibits good fatigue resistance with a resistance change of less than 5% after repeated bending 50,000 times.

[0049] Preferably, in this embodiment, the coating used for antithrombosis is a phosphorocholine-inspired biomimetic coating. This coating is formed on the surface of the petal-shaped electrode 2 by dip coating or chemical vapor deposition, creating a polymer coating containing phosphorocholine groups. The thickness of this phosphorocholine-inspired biomimetic coating is 3 μm to 5 μm, preferably 4 μm in this embodiment. The refractive index of the phosphorocholine-inspired biomimetic coating is close to that of blood, and it does not produce strong reflection artifacts under OCT imaging, which is beneficial for intraoperative image observation. This coating also does not block pulsed current transmission and can effectively inhibit contact coagulation activation.

[0050] Preferably, the positioning mark 6 is a radiopaque metal imaging ring made of platinum-iridium alloy with a wall thickness of 0.03 mm to 0.06 mm and a length of 1.0 mm to 2.5 mm, respectively disposed on the outer ends of the petal-shaped electrode 2 along the axial distribution range of the ablation catheter body 1. The electrocardiogram synchronization signal interface is also located at the proximal end of the ablation catheter body 1, including at least two electrocardiogram signal input terminals.

[0051] Preferably, the control mechanism is a spiral knob, used to drive the traction wire to move axially along the ablation catheter body 1, thereby causing the petal-shaped electrodes 2 to switch between a retracted state and an extended state. By rotating the knob, the operator transmits force to the distal end of the electrode head through the traction wire, overcoming or releasing the elastic force of the flexible substrate 3, thus realizing the retraction or extension of the petal-shaped electrodes 2.

[0052] Preferably, in this embodiment, the outer diameter of the electrode tip when folded is less than or equal to 1.5 mm, allowing it to be inserted through a standard 6F arterial sheath. The nominal working diameter in the unfolded state can be adaptively matched according to the coronary artery diameter, ranging from 2.0 mm to 4.0 mm. The non-circumferential petal structure only covers approximately 5 / 9 of the vessel wall circumferentially, naturally forming blood flow channels on the opposite sides and between each petal, ensuring continuous unobstructed coronary blood flow during pulsed discharge and between discharge intervals.

[0053] Example 3: This embodiment provides a non-full-circumference petal-shaped pulsed electric field ablation electrode head. Unlike embodiment 1, it adopts a five-petal structure to adapt to the ablation requirements of larger tube diameters or asymmetric myocardial bridges 5, and further explains the grouping control mode of each petal-shaped electrode 2.

[0054] Preferred, see Figures 2-4The electrode head comprises five independent petal-shaped electrodes 2, namely petal-shaped electrode 2a, petal-shaped electrode 2b, petal-shaped electrode 2c, petal-shaped electrode 2d, and petal-shaped electrode 2e. Three main valve electrodes (petal-shaped electrodes 2b, 2c, and 2d) are concentrated to cover the target area, corresponding to the thickest part of the myocardial bridge 5 along the vessel wall direction; two auxiliary valve electrodes (petal-shaped electrodes 2a and 2e) are located on either side of the main valves. The five petal-shaped electrodes 2 cover approximately 240° (about 2 / 3 circumference) of the coronary artery wall 7, with approximately 120° on the opposite side and the gaps between the valves forming a blood flow channel. The equivalent cross-sectional area of ​​the blood flow channel is not less than 30% of the cross-sectional area of ​​the coronary artery lumen where the electrode head is located, ensuring unobstructed blood flow throughout the ablation process.

[0055] Preferably, the flexible substrate 3 of each petal-shaped electrode 2 is a silicone substrate with a thickness of 0.08 mm to 0.15 mm, preferably 0.08 mm in this embodiment, and its own elastic support force is ≤5 g. A conductive electrode layer 4 is disposed on the outer surface of the flexible substrate 3, and is made of gold, formed on the outer surface of the silicone substrate by sputtering deposition. The thickness of the conductive electrode layer 4 is 5 μm to 20 μm, preferably 8 μm in this embodiment. The conductive electrode layer 4 maintains conductive continuity when the silicone substrate deforms.

[0056] Preferably, in the retracted state, each petal-shaped electrode 2 is attached to the outer surface of the catheter body 1, with a maximum outer diameter less than or equal to 1.5 mm. In this embodiment, it is preferably 1.48 mm, and can be inserted through a standard 6F arterial sheath. The nominal working diameter in the unfolded state is 4.0 mm, suitable for coronary arteries with a reference diameter of 3.5 mm to 4.0 mm. The non-full-circumference petal structure only covers about 2 / 3 of the circumferential wall of the catheter, and the approximately 120° area on the opposite side and the gaps between the valves naturally form blood flow channels.

[0057] The following is a comparison between the non-full-circumference petal-shaped pulsed electric field ablation electrode heads of Examples 1-3 and existing technologies.

[0058] Compared to existing ring-shaped or balloon-shaped electrode tips, the non-circumferential petal-shaped pulsed electric field ablation electrode tips of embodiments 1-3 have a non-circumferential petal structure that covers only 1 / 2–2 / 3 of the vessel wall circumferentially. Natural blood flow channels are formed between the contralateral sides and between each petal, ensuring continuous unobstructed coronary blood flow during pulsed discharge and the discharge interval. This completely eliminates the risk of acute myocardial ischemia caused by full-circumferential ring electrodes, allowing ablation operations to be performed safely under conditions of continuous myocardial perfusion. The surgical time window is no longer strictly limited by blood flow occlusion. By concentrating the petal-shaped electrodes 2 on one side, the pulsed electric field is radiated outwards directionally from the petal-shaped electrodes 2, with the maximum field strength pointing towards the ablation target area (the location of myocardial bridge 5), minimizing the electric field exposure of the vessel wall outside the target area. Combined with independent petal-shaped electrode 2 control, a petal-by-petal directional discharge strategy can be implemented for eccentric, asymmetric myocardial bridges 5. By setting the support force of the ultra-thin flexible silicone base to ≤5g, it can adaptively adhere to the vascular wall without balloon expansion. The adhesion pressure is far below the vascular intima damage threshold (the adhesion pressure is more than 4 times lower than the vascular intima safety threshold of about 20g), and there is no mechanical compression damage to the vessel wall throughout the operation. The covalently grafted heparin or phosphoric acid choline biomimetic coating significantly inhibits contact coagulation, extending the safe operation time in the coronary artery from the conventional <30 minutes to >60 minutes, providing a sufficient safe operation window for segmental ablation of long-segment myocardial bridge 5. It is equipped with an electrocardiogram synchronization signal interface, which triggers pulse discharge during diastole (400ms-600ms after R wave) based on the R wave to achieve electrocardiogram synchronized ablation. With the electrode tip retracted to an outer diameter of ≤1.5mm, it can be inserted through a standard 6F arterial sheath, adapting to the standard equipment and operating procedures of existing coronary intervention catheterization labs, without the need for special equipment modification, and has a low threshold for clinical promotion.

[0059] The structure and working principle of the present invention will be further explained below: The purpose of this invention is to provide a non-circumferential petal-shaped pulsed electric field ablation electrode tip. During surgical procedures, a 6F arterial sheath is first inserted via radial artery puncture. Guided by a guidewire, the electrode tip, in its retracted state, is advanced along the arterial sheath to the target myocardial bridge segment 5 of the coronary artery. Under X-ray fluoroscopy, the axial position and circumferential orientation of the electrode tip are confirmed by two contrast rings 6 located on the outer sides of the axial distribution range of the petal-shaped electrodes 2, ensuring that each petal-shaped electrode 2 is aligned with the side wall of the coronary artery where the myocardial bridge 5 is located.

[0060] After the position is confirmed, operate the control mechanism at the proximal end of the catheter by rotating the spiral knob or pushing / pushing the handle to drive the traction wire to move axially along the catheter body 1, releasing the constraint on the petal-shaped electrodes 2. Under the action of the elastic recovery force of the ultra-thin flexible silicone substrate 3, each petal-shaped electrode 2 unfolds in an arc towards one side of the catheter body 1, forming a petal-shaped structure. The thickness of the flexible substrate 3 is 0.08mm to 0.15mm, and its own elastic support force is ≤5g. Under the condition of no external expansion force source, it achieves adhesion to the inner wall of the blood vessel by relying on the elasticity of the material itself. The adhesion pressure is more than 4 times lower than the safe threshold of the blood vessel intima (about 20g), effectively avoiding mechanical compression damage to the intima. After unfolding, the conductive electrode layer 4 on the outside of the petal-shaped electrode 2 is pushed towards the coronary artery wall 7, achieving stable adhesion to the target area vessel wall.

[0061] In the deployed state, each petal-shaped electrode 2 is concentrated on one side of the axial direction of the catheter body 1, occupying only 1 / 2 to 2 / 3 of the circumferential area of ​​the coronary artery wall (in Example 1, 3 petal-shaped electrodes 2 cover about 1 / 2 of the circumference, and in Example 3, 5 petal-shaped electrodes 2 cover about 2 / 3 of the circumference). The contralateral wall area and the gaps between adjacent petal-shaped electrodes 2 together form an open fluid channel, i.e., a blood flow channel, which is C-shaped or crescent-shaped, with an equivalent cross-sectional area not less than 30% of the cross-sectional area of ​​the coronary artery lumen where the electrode tip is located. This structure fundamentally avoids the risk of vascular occlusion associated with full-circumferential ring electrodes, allowing ablation operations to be performed safely under conditions of continuous myocardial perfusion. Coronary blood flow remains unobstructed during pulsed discharge and between discharge intervals, and the surgical time window is no longer strictly limited by blood flow occlusion.

[0062] After confirming that the blood flow channel is unobstructed, the ECG synchronization signal interface is connected to an external ECG monitoring device. The surface ECG signal is filtered and amplified before being sent to the existing ablation control host. The host identifies the R wave and triggers a pulse discharge during diastole (400ms to 600ms after the R wave) based on the R wave. The pulse electric field radiates directionally from the conductive electrode layer 4 of each petal-shaped electrode 2 to the outside of the tube wall, and penetrates through the tube wall into the myocardial bridging tissue 5.

[0063] During ablation, because each petal-shaped electrode 2 is physically separated and centrally arranged on one side, and each petal-shaped electrode 2 is connected to an independent insulated conductive lead, with each conductive lead extending along the inner lumen of the catheter body 1 to the proximal interface of the catheter and being mutually insulated, the external system can independently control the on / off state, independent polarity configuration, and independent energy output of each petal-shaped electrode 2. By independently controlling the polarity, discharge timing, and energy of each petal-shaped electrode 2, a directional electric field can be constructed within the fan-shaped area covered by the petal-shaped electrode 2, achieving precise targeted ablation of the eccentric and asymmetric myocardial bridge 5, while minimizing the electric field exposure of the catheter wall in the uncovered area.

[0064] Simultaneously, the surface of the petal-shaped electrode 2 is coated with an antithrombotic coating 8, which forms an antithrombotic interface through covalently grafted heparin (molecular weight 4000-6000 Da, coating thickness 2μm-3μm) or a phosphocholine-inspired coating (thickness 3μm-5μm). This effectively inhibits contact coagulation activation and mural thrombus formation during intracoronary procedures lasting over 60 minutes, extending the safe duration of the procedure. The thickness of the antithrombotic coating does not affect the macroscopic dimensions of the petal-shaped electrode 2 and does not obstruct pulsed current transmission.

[0065] The impedance monitoring circuit provides real-time feedback on the ablation progress, and automatically stops output when the cumulative energy at a single point reaches 18J. After ablation is completed, the traction wire is pulled proximally by the control mechanism to overcome the elastic force of the flexible substrate 3, and the petal-shaped electrodes 2 are gathered and attached to the outer surface of the catheter body 1 (gathered outer diameter ≤ 1.5mm). Then the electrode head is removed from the body.

[0066] When this invention is specifically applied in clinical practice, taking superficial myocardial bridging with a thickness of 0–3 mm as an example, it includes the following steps: Step 1: Establish a vascular interventional pathway and insert the pulsed electric field ablation catheter along the guidewire into the lumen of the coronary artery myocardial bridge lesion segment. The distal end of the ablation catheter is equipped with a non-circumferential petal-shaped pulsed electric field ablation electrode.

[0067] Step 2: Release the flexible electrode assembly of the electrode head, allowing several petal-shaped electrodes 2, which are concentrated in the axial unilateral region of the ablation catheter body 1, to transform from a retracted state to an unfolded state under the action of their own elastic restoring force. Each petal-shaped electrode 2 is not fully attached to the inner wall of the coronary artery vessel wall 7. The petal-shaped electrodes 2 only occupy 1 / 2 to 2 / 3 of the circumferential region of the coronary vessel wall. The vessel wall area not covered by the petal-shaped electrodes 2 and the gaps between adjacent petal-shaped electrodes 2 together form a blood flow channel, maintaining continuous unobstructed coronary blood flow throughout the ablation process and eliminating the risk of vascular occlusion and acute ischemia.

[0068] Step 3: Based on the preset coronary artery depth-limiting pulse parameters (field strength 650V / cm~850V / cm, pulse width 1μs~2μs, biphasic symmetrical waveform, single-point cumulative energy ≤18J), combined with ECG monitoring to lock the diastolic phase of the heart, a biphasic microsecond pulse electric field discharge is synchronously triggered, so that the pulse electric field penetrates directionally from inside the coronary artery lumen to outside the lumen.

[0069] Step 4: Utilizing the difference in electric field tolerance thresholds between cardiomyocytes and vascular tissue (the irreversible electroporation threshold for cardiomyocytes is 650V / cm~850V / cm, while the tolerance threshold for coronary artery smooth muscle cells is greater than 1200V / cm), the superficial myocardial bridge 5 on the outer surface of the coronary artery is selectively ablated from the inside out. Irreversible electroporation induces apoptosis of the cardiomyocytes in the myocardial bridge 5, thereby relieving the mechanical compression of the coronary artery by the myocardial bridge 5 during systole.

[0070] Furthermore, there is a significant difference in electric field tolerance thresholds between cardiomyocytes and vascular smooth muscle cells. The irreversible electroporation threshold for cardiomyocytes is 650–850 V / cm (related to cell size and morphology), while the tolerance threshold for coronary artery smooth muscle cells is greater than 1200 V / cm. By precisely limiting the ablation field strength within a treatment window of 650–850 V / cm, it is possible to induce irreversible electroporation and apoptosis only in superficial myocardial bridging cells within a transmural depth of 3 mm, while completely preserving the structural and functional integrity of the three layers of the coronary artery (endothelium, smooth muscle, and adventitia).

[0071] Furthermore, the pulsed electric field radiates directionally from inside the cavity outwards, and the ablation depth is positively correlated with the field strength, achieving an average penetration depth of approximately 1.7 mm per 500 V / cm. By precisely controlling the voltage output (±5%), sub-millimeter-level precise control of the ablation depth can be achieved. These characteristics enable this invention to provide personalized depth-limiting parameter schemes for superficial myocardial bridges of different thicknesses (1.8 mm / 2.5 mm / 3.0 mm).

[0072] Furthermore, the diastolic phase of the heart is the optimal time window for ablation. During ventricular diastole, the mechanical compression of the coronary artery by the myocardial bridge is minimal, the coronary lumen is maximized, the electrode adheres most stably to the vessel wall, and the relative displacement between the electrode and the target tissue is minimal (<0.2 mm). Binding diastolic ablation can effectively avoid ablation position displacement and uneven energy distribution caused by heartbeats.

[0073] The following five representative experimental cases illustrate the beneficial effects of the non-circumferential petal-shaped pulsed electric field ablation electrode head described in this invention, covering cases with different muscle bridge thicknesses, target vessels, coronary artery diameters, symmetrical / asymmetrical morphologies, and long segmental complexities.

[0074] Experimental Example 1: Superficial anterior descending artery myocardial bridging (standard thickness, standard diameter) Patient: A 45-year-old male with drug-resistant superficial myocardial bridging in the left anterior descending artery. Coronary angiography: Approximately 70% stenosis in the mid-segment of the left anterior descending artery during systole, disappearing during diastole. CTA: Bridging thickness approximately 2.5 mm, reference coronary artery diameter approximately 3.0 mm.

[0075] Experimental Procedure: Step 1: Establish a vascular interventional pathway via the right radial artery, insert a 6F arterial sheath, and advance the ablation catheter along the guidewire to the proximal segment of the myocardial bridging in the left anterior descending artery. The petal electrode is in a closed state, with an outer diameter ≤1.5mm, and passes smoothly through the sheath. Step 2: Confirm catheter placement under X-ray fluoroscopy and contrast ring guidance, and release petal electrode 2. Petal electrode 2a does not fully adhere to the coronary artery wall. The electrode occupies only about 1 / 2 of the circumferential area of ​​the vessel wall, ensuring complete patency of the contralateral blood flow channel and no obstruction of coronary blood flow. Step 3: Set pulse parameters—field strength 750V / cm, pulse width 1.5μs, biphasic symmetrical waveform, and single-point cumulative energy 15J. The ECG synchronization system automatically identifies the R wave and triggers discharge 480ms after the R wave. Step 4: The pulsed electric field radiates directionally from the vessel wall outwards, precisely covering the myocardial bridging region 5 at a depth of 2.5mm. Because the set field strength of 750V / cm is far below the vascular tolerance threshold (>1200V / cm), the coronary artery wall is completely undamaged. Step 5: After a single discharge, the catheter is moved forward 5mm to perform segmented band ablation (adjacent segments overlap by 1–2mm), covering a total length of approximately 20mm. During the experiment, 200μg of nitroglycerin was injected into the coronary artery to prevent spasm. Step 6: Post-ablation coronary angiography showed that systolic stenosis improved from 70% to <15%.

[0076] Results: At the 3-month follow-up after the experiment, the chest pain disappeared and the exercise stress test was negative.

[0077] Experimental Example 2: Moderate right coronary artery myocardial bridging (upper limit thickness, larger diameter) Patient: A 58-year-old male with drug-resistant right coronary artery myocardial bridging. Coronary angiography: systolic stenosis of approximately 80% in the mid-distal segment of the right coronary artery; CTA measurement of the bridging thickness was approximately 3.0 mm, and the reference coronary artery diameter was approximately 3.8 mm. A large-size petal electrode (nominal unfolding diameter 4.0 mm) was selected, with a field strength set to 850 V / cm (3.0 mm is the upper limit of the indicated thickness; the upper limit field strength was used to ensure full-thickness penetration), a pulse width of 1.8 μs, and a single-point energy of 18 J. During the experiment, 1 mg of diltiazem was injected intracoronaryly to prevent spasm.

[0078] Results: The stenosis improved from 80% to <15% after the experiment. The set field strength of 850V / cm was far below the vascular threshold of >1200V / cm, with a safety margin of more than 1.4 times. Angina pectoris disappeared 6 months after the experiment.

[0079] Experimental Example 3: Thin-walled anterior descending artery myocardial bridging (small thickness, small diameter) Patient: A 38-year-old female with superficial myocardial bridging in the left anterior descending artery. CTA measurements showed a bridging thickness of approximately 1.8 mm and a coronary artery reference diameter of approximately 2.5 mm. A small-sized petal electrode (nominal unfolded diameter 2.5 mm) was selected, occupying only about 1 / 3 of the circumferential area of ​​the vessel wall to maximize coronary blood flow. The field strength was set to 500 V / cm (a lower field strength is sufficient for full-thickness penetration of a 1.8 mm thin myocardial bridging); the pulse width was 1.0 μs, and the single-point energy was 8 J. During the experiment, 150 μg of nitroglycerin was injected intracoronaryly.

[0080] Results: After the experiment, the stenosis improved from 55% to <10%, with a safety margin >2.4 times. Six months after the experiment, chest pain disappeared, and the ECG returned to normal under exercise load.

[0081] The parameter comparison table is as follows:

[0082] Experiments 1-3 established that the electric field strength was positively correlated with the thickness of the myobridge (approximately 200–250 V / cm / mm), consistently remaining below the vascular tissue tolerance threshold (1200 V / cm). The electrode size was matched to the coronary artery diameter, with circumferential coverage controlled at 1 / 3–1 / 2 to ensure continuous opening of the contralateral blood flow channel. These three sub-modules worked collaboratively to ensure precise control of the ablation depth and vascular safety.

[0083] Experiment Example 4: Petal Electrode Independent Control Mode – Asymmetric Myocardial Bridging Patient: A 52-year-old male with asymmetrical superficial myocardial bridging in the left anterior descending artery. IVUS examination: The myocardial bridging is eccentrically distributed, occupying only a 120° fan-shaped area on the outer side of the coronary artery wall (corresponding to the 1 o'clock to 5 o'clock direction). The thickness of the myocardial bridging is uneven (thickest 2.8 mm, thinnest 1.5 mm).

[0084] The five petal electrodes are numbered and controlled according to a preset independent control scheme: petal electrodes 2c and 2d are set to target discharge (field strength 800V / cm, 15J) to cover the thickest part of the muscle bridge; petal electrodes 2b and 2e are set to assist reflux (field strength 300V / cm) to build only a closed loop; petal electrode 2a is set to sleep monitoring, without applying pulses, only collecting the reference potential of the opposite tube wall.

[0085] The ablation sequence is as follows: Sequence 1 uses petal-shaped electrode 2c as the positive electrode and petal-shaped electrode 2d as the negative electrode, directionally penetrating and covering the thickest area of ​​the 2.8mm muscle bridge; Sequence 2 uses petal-shaped electrode 2d as the positive electrode and petal-shaped electrode 2b as the negative electrode, covering the thinner area of ​​the 1.5mm muscle bridge; polarity switching: the polarity of petal-shaped electrode 2c and petal-shaped electrode 2d are automatically exchanged, and sequence 1 is repeated to ensure uniform electroporation throughout the entire layer.

[0086] Real-time feedback: When the impedance of the target area tracked by the petal-shaped electrode 2e drops from 88Ω to 45Ω (below 55% of the initial value), the system automatically determines that ablation is complete and stops subsequent discharge.

[0087] Safety verification: The petal-shaped electrode 2a dormant electrode monitoring showed that the impedance of the non-target area remained at 82–90Ω and the transwall potential was <50V / cm, confirming that the non-target area blood vessels were completely unaffected by the electric field.

[0088] Results: Stenosis improved from 65% to approximately 10% after the experiment. Electric field exposure in the non-target vessel wall decreased to less than 1 / 5 of that in the conventional all-electrode synchronous mode. Six months after the experiment, CTA showed stable lumen morphology with no restenosis or aneurysmal dilatation.

[0089] Experimental Example 5: Application of Antithrombotic Coating – Long Segment Diffuse Myocardial Bridging Patient: A 58-year-old female with diffuse superficial myocardial bridging along the entire length of the left anterior descending artery, with a bridging segment length of approximately 45 mm (a rare case of a long segment). The thickness of the myocardial bridging was uneven (1.8–3.0 mm), and she also had type 2 diabetes, hyperlipidemia, and a mild hypercoagulable state (D-dimer 0.8 mg / L).

[0090] Antithrombotic coating scheme: A heparin covalent grafting coating is employed—active hydroxyl groups (-OH) are introduced into a flexible silicone substrate through oxygen plasma treatment. Low molecular weight heparin (5000 Da, anticoagulant activity ≥150 IU / mg) is then activated at the end groups and covalently bonded to form a monolayer coating with a thickness of 2–3 μm. This thickness does not increase the macroscopic size of the electrode flap (the outer diameter remains ≤1.5 mm when closed) and does not affect the electrode conductivity or pulse transmission efficiency.

[0091] The ablation was performed in nine segments (each 5 mm, with a 1–2 mm overlap). The proximal segment (1.8 mm) had a field strength of 650 V / cm and an energy of 10 J; the mid-segment (2.5–3.0 mm) had a field strength of 800 V / cm, a pulse width of 2.0 μs, and an energy of 16 J; and the distal segment (2.2 mm) had a field strength of 700 V / cm and an energy of 12 J. The entire ablation process took 48 minutes, with the catheter remaining in the coronary artery for 65 minutes. Bedside TEG monitoring every 15 minutes showed no significant changes in the R value (5.2–5.5–5.4 min) and MA value (62–60–61 mm) throughout the procedure, confirming that the coating effectively inhibited contact clotting.

[0092] The comparison of the antithrombotic coating effects in Experiment 5 is shown in the table below:

[0093] Results: OCT 7 days post-experiment: smooth coronary artery walls, no mural thrombi. 3 months post-experiment: endothelial coverage >95%. 6 months post-experiment: no chest pain, no myocardial infarction, no restenosis.

[0094] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the above embodiments should be considered exemplary rather than restrictive in all respects; the scope of protection of the present invention is defined by the appended claims, not by the foregoing description, and thus all changes falling within the meaning and scope of the equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0095] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity; those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is merely illustrative of the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solutions based on the technical concept proposed in this invention fall within the scope of protection of the claims of this invention.

Claims

1. A non-full-circumference petal-shaped pulsed electric field ablation electrode head, disposed at the end of the ablation catheter body (1), characterized in that, include: The flexible electrode assembly includes several petal-shaped electrodes (2) centrally arranged in the axial unilateral region of the ablation catheter body (1). Each petal-shaped electrode (2) includes a flexible substrate (3) located on the inner side and a conductive electrode layer (4) located on the outer side. The flexible substrate (3) is used to drive the petal-shaped electrode (2) from a closed state to an unfolded state under its own elastic restoring force. In the unfolded state, the tube wall area not covered by the petal-shaped electrode (2) and the gap between each adjacent petal-shaped electrode (2) together form a liquid channel. Several conductive leads, the conductive electrode layer (4) of each petal-shaped electrode (2) is connected to an independent conductive lead, and each conductive lead extends along the inner lumen of the ablation catheter body (1) to the proximal interface of the catheter. Positioning marks (6) are respectively set on the outer sides of both ends of the petal-shaped electrode (2) along the axial distribution range of the ablation catheter body (1) to confirm the position and / or orientation of the electrode head under imaging; The control mechanism is located at one end of the ablation catheter body (1) and connected to each petal-shaped electrode (2) to drive each petal-shaped electrode (2) to switch between the closed state and the unfolded state.

2. The non-full-circumference petal-shaped pulsed electric field ablation electrode head according to claim 1, characterized in that, In the closed state, each petal-shaped electrode (2) is closed along the axial direction of the ablation catheter body (1) and attached to the outer surface of the ablation catheter body (1); In the unfolded state, each petal-shaped electrode (2) unfolds in an arc towards one side of the ablation catheter body (1) through the elastic restoring force of the flexible substrate (3).

3. The non-full-circumference petal-shaped pulsed electric field ablation electrode head according to claim 1, characterized in that, The ablation catheter body (1) is provided with a traction wire. One end of the traction wire is connected to each petal-shaped electrode (2), and the other end of the traction wire is connected to the control mechanism.

4. The non-full-circumference petal-shaped pulsed electric field ablation electrode head according to claim 3, characterized in that, The control mechanism is a push-pull handle or a spiral knob, used to drive the traction wire to move axially along the ablation catheter body (1), and drive each petal electrode (2) to switch between the closed state and the unfolded state.

5. The non-full-circumference petal-shaped pulsed electric field ablation electrode head according to claim 1, characterized in that, The number of petal-shaped electrodes (2) is 3 to 5; the circumferential gap angle between adjacent petal-shaped electrodes (2) is 15° to 30°, and the axial spacing is 1 to 2 mm.

6. The non-full-circumference petal-shaped pulsed electric field ablation electrode head according to claim 1, characterized in that, The flexible substrate (3) is a silicone substrate with a thickness of 0.08 to 0.15 mm and a self-elastic support force of ≤5 g. The thickness of the conductive electrode layer (4) is 5 to 20 μm.

7. The non-full-circumference petal-shaped pulsed electric field ablation electrode head according to claim 1, characterized in that, The flexible substrate (3) is a butterfly-shaped or willow-leaf-shaped thin sheet.

8. The non-full-circumference petal-shaped pulsed electric field ablation electrode head according to claim 1, characterized in that, The surface of the petal-shaped electrode (2) is also provided with a heparin covalent graft coating or a phosphocholine biomimetic coating. The thickness of the heparin covalent graft coating is 2-3 μm, and the thickness of the phosphocholine biomimetic coating is 3-5 μm.

9. The non-full-circumference petal-shaped pulsed electric field ablation electrode head according to claim 1, characterized in that, The positioning mark (6) is an X-ray-proof metal imaging ring with a wall thickness of 0.03 to 0.06 mm and a length of 1.0 to 2.5 mm. The distance between the two metal developing rings is 15–25 mm.

10. The non-full-circumference petal-shaped pulsed electric field ablation electrode head according to claim 1, characterized in that, The ablation catheter body (1) is also provided with an electrocardiogram synchronization signal interface at its end. The electrocardiogram synchronization signal interface includes at least two electrocardiogram signal input terminals for connecting to an external electrocardiogram monitoring device.

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