An ablation catheter having a dual-layer basket support

Abstract

This invention relates to the field of medical device technology and discloses an ablation catheter with a double-layer basket support, comprising a tip, an outer support rod, a lower support rod, and a sheath core. A sheath core locking cavity is formed inside the tip, and the end of the sheath core is fixed inside the sheath core locking cavity. A radial through-hole is formed on the sidewall of the tip, and the end of the outer support rod is inserted into the radial through-hole. A catheter is sleeved on the outside of the sheath core, with the lower support rod located on the side of the outer support rod away from the tip, and the lower support rod is fixedly connected to the end of the catheter. A cutting node is formed between the outer and lower support rods. An upper electrode is embedded on the outer support rod, and a lower electrode is embedded on the lower support rod. This invention uses the movement of the sheath core to cause synchronous radial deformation of the outer and lower support rods, allowing the upper and lower electrodes to respectively adhere to the inner wall tissue of corresponding areas, achieving dual-region circumferential potential isolation in a single operation.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to an ablation catheter with a double-layer basket support. Background Technology

[0002] During mapping and ablation treatment of paroxysmal atrial fibrillation, the ablation catheter needs to penetrate deep into the pulmonary vein region. Existing ablation catheters typically employ a single-layer basket structure or a single expansion structure. When a conventional basket stent expands and deforms within the vessel, the single expansion size cannot simultaneously match the spatial anatomical differences between the pulmonary vein ostium and the pulmonary vein vestibule. After completing the ablation of the pulmonary vein ostium region, the physician needs to readjust the axial position of the ablation catheter and re-control the degree of stent deformation before continuing ablation of the pulmonary vein vestibule region. A single-distributed ablation array cannot simultaneously cover both the pulmonary vein ostium and the pulmonary vein vestibule while maintaining the same catheter axial position.

[0003] Existing scaffold structures lack multi-regional coordinated deformation constraints when radial deformation occurs, and cannot form a stepped three-dimensional contour that adapts to different anatomical sites. This results in some ablation electrodes failing to fully adhere to the target tissue, affecting the continuity of ablation blockade.

[0004] Meanwhile, the electrodes on the surface of existing ablation catheters typically protrude directly from the outer surface of the stent. The protruding electrode edges are prone to direct scraping against the vessel wall during the advancement or retraction of the ablation catheter, increasing the risk of damage to the inner wall tissue. Conventional electrodes lack corresponding limiting blocks on the stent; when the stent bends or deforms or is compressed by surrounding tissue, the electrode is prone to axial sliding displacement on the stent, deviating from its intended ablation position, or even completely detaching from the stent, causing the ablation catheter to lose its normal electrical conduction function. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an ablation catheter with a double-layer basket support, which solves the problem that existing ablation catheters are difficult to adapt to the different anatomical sizes of the pulmonary vein orifice and pulmonary vein vestibule during mapping and ablation, and cannot simultaneously meet the requirements of tissue adhesion and ablation isolation in different regions at a single axial position.

[0006] To achieve the above objectives, the present invention provides the following technical solution: The present invention provides an ablation catheter with a double-layer basket support, comprising a tip, an outer support rod, a lower support rod, and a sheath core inserted along the central axis; The tip head has a sheath core locking cavity along the central axis inside. The end of the sheath core is fixedly connected to the inside of the sheath core locking cavity. The cylindrical sidewall of the tip head has radial through holes along the central axis. The ends of a total of 6 outer support rods are respectively inserted radially into the inside of a corresponding radial through hole of the tip head. The outer side of the sheath core is fitted with a catheter, and a total of 6 lower support rods are located on the side of the outer support rod away from the tip. The ends of each lower support rod away from the outer support rod are fixedly connected to the end surface of the catheter near the tip. A cutting node is integrally formed between the outer support rod and the lower support rod at the axial middle position along the central axis.

[0007] As a preferred embodiment, the tip has a top surface, and the edge of the tip near the top surface is provided with a scratch-resistant rounded corner. The scratch-resistant rounded corner has a smooth arc-shaped transition surface, so that the front end of the tip forms a structure without sharp edges.

[0008] As a preferred embodiment, the six outer support rods bend and expand away from the central axis between the tip head and the cutting node, and the six outer support rods together form the upper structure. The six lower support rods bend and expand away from the central axis between the cutting node and the end of the conduit, and the six lower support rods together form the lower structure.

[0009] As a preferred embodiment, under the natural state where no external axial force is applied to the sheath core, the upper structure has a first maximum outer diameter perpendicular to the central axis, the lower structure has a second outer diameter perpendicular to the central axis, and the value of the first outer diameter is smaller than the value of the second outer diameter.

[0010] As a preferred embodiment, an upper electrode is fitted to the outside of the outer support rod, and a lower electrode is fitted to the outside of the lower support rod. Electrode mounting grooves are formed on the outer and lower outer surfaces of both the outer and lower support rods. The upper electrode is fixedly fitted inside the electrode mounting groove of the outer support rod, and the lower electrode is fixedly fitted inside the electrode mounting groove of the lower support rod.

[0011] As a preferred embodiment, the radial depth of the inward recess of the electrode mounting groove is equal to the wall thickness of the annular solid of the upper electrode, and the radial depth of the inward recess of the electrode mounting groove is equal to the wall thickness of the annular solid of the lower electrode. The two end faces of the electrode mounting groove in the axial direction form metal solid limiting steps perpendicular to the outer surface of the outer support rod or the outer surface of the lower support rod.

[0012] As a preferred embodiment, six upper electrodes are distributed in the axial middle region of six outer support rods. The six upper electrodes form a first annular ablation array around the central axis in three-dimensional space. A total of 12 lower electrodes are distributed on the outwardly expanding arc-shaped segments of the six lower support rods. The 12 lower electrodes form a second annular ablation array arranged in two layers around the central axis in three-dimensional space.

[0013] As a preferred embodiment, a loader is fitted on the outside of the catheter. The loader is a tubular solid structure. An annular receiving cavity is defined between the inner wall of the loader and the outer surface of the sheath core and the catheter. The edge of the loader near the tip contacts the outer surface of the lower support rod.

[0014] As a preferred embodiment, the radial extension depth of the tip head radial through hole inside the tip head is less than the distance between the outer surface of the tip head and the outer wall of the sheath core locking cavity. The six tip head radial through holes are distributed in the outer space of the sheath core locking cavity. A solid material spacer structure is maintained between the innermost bottom surface of each tip head radial through hole and the side wall of the sheath core locking cavity.

[0015] As a preferred embodiment, the outer support rod and the lower support rod are made of a single metal tube, and the cutting node is a continuous transition zone of nickel-titanium alloy solid material with a V-shaped bifurcation configuration.

[0016] This invention provides an ablation catheter with a double-layer basket support. It has the following beneficial effects: 1. This invention involves setting an outer support rod and a lower support rod on the outside of the catheter, and integrally forming a cutting node between the outer and lower support rods. Combined with the structure of the sheath core being fixed inside the tip, the sheath core is moved along the central axis. The axial force applied by the sheath core is transmitted to the outer support rod through the tip, and then transmitted between the outer and lower support rods through the cutting node. This causes the outer and lower support rods to undergo synchronous radial elastic deformation, thereby changing the outer diameter of the expansion and matching the anatomical size requirements of the pulmonary vein orifice and pulmonary vein vestibule.

[0017] 2. This invention establishes an upper electrode on an outer support rod and a lower electrode on a lower support rod, forming a first and a second annular ablation array in space. The sheath core is operated to generate axial displacement, and the upper electrode and lower electrode simultaneously undergo radial displacement, allowing the upper electrode to adhere to the inner wall of the pulmonary vein orifice and the lower electrode to adhere to the inner wall of the pulmonary vein vestibule. This establishes an electrical contact interface for the corresponding anatomical regions without altering the axial position of the catheter tip, thus achieving coverage and isolation of different anatomical areas.

[0018] 3. This invention involves creating electrode mounting grooves on the outer and lower outer surfaces of the stent and the upper stent, respectively. The radial depth of the inward recess of the electrode mounting groove is equal to the wall thickness of the annular solid of the upper and lower electrodes. The two end faces of the electrode mounting groove in the axial direction form metal solid limiting steps perpendicular to the surface of the outer or lower stent. The metal solid limiting steps restrict the sliding displacement of the upper and lower electrodes in the axial direction, preventing the upper and lower electrodes from detaching from the outer and lower stents. The outermost surfaces of the upper and lower electrodes are flush with the surfaces of the outer and lower stents, respectively, avoiding damage to the vascular wall tissue by protruding structures. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a top view of the structure of the present invention; Figure 3 This is a schematic diagram of the compressed state structure of the present invention; Figure 4 This is a schematic diagram of the natural state structure of the present invention; Figure 5 This is a schematic diagram of the spindle-shaped state structure of the present invention.

[0020] Among them, 1. Tip head; 2. Sheath core locking cavity; 3. Tip head radial through hole; 4. Outer support rod; 5. Cutting node; 6. Lower support rod; 7. Upper electrode; 8. Lower electrode; 9. Electrode mounting groove; 10. Sheath core; 11. Loader; 12. Annular receiving cavity; 13. Scratch-resistant rounded corner; 14. Conduit. Detailed Implementation

[0021] The technical solutions in 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.

[0022] See attached document Figure 1 -Appendix Figure 5 This invention provides an ablation catheter with a double-layer basket support, including a tip head 1, an outer support rod 4, a lower support rod 6, and a sheath core 10 extending along the central axis. The tip head 1 is a cylindrical solid structure. The tip head 1 has a top surface.

[0023] The tip 1 has a scratch-resistant rounded corner 13 near the edge of its top surface. The scratch-resistant rounded corner 13 has a smooth, rounded transition surface, making the tip of the tip 1 without sharp edges. When the tip 1 is advanced axially inside a patient's blood vessel or heart chamber, the scratch-resistant rounded corner 13 prevents the edge of the tip 1 from directly contacting the inner wall of the blood vessel or heart chamber, thus avoiding tissue damage.

[0024] In this embodiment, the tip head 1 has a blind-hole-shaped sheath core locking cavity 2 with an opening facing away from the top surface and an axial depth limited by the length of the tip head 1. The end of the sheath core 10 is fixedly connected to the inside of the sheath core locking cavity 2. The sheath core 10 penetrates the central area formed by the outer support rod 4 and the lower support rod 6, and the sheath core 10 and the tip head 1 form a cantilever load transfer structure that transmits loads in both axial tension and compression.

[0025] The reciprocating axial driving force generated by the sheath core 10 is converted into the displacement increment of the tip head 1. As a preferred method, the central driving form, combined with the symmetrical arrangement of the outer support rods 4, keeps the stress on the outer support rods 4 in balance under deformation and maintains circumferential consistency. Six radial through holes 3 are evenly opened at equal angles along the central axis on the cylindrical sidewall of the tip head 1.

[0026] Each tip head radial through hole 3 extends radially into the tip head 1. The ends of a total of 6 outer support rods 4 are respectively inserted radially into the interior of a corresponding tip head radial through hole 3. The end surfaces of the outer support rods 4 are fixedly connected to the hole walls of the tip head radial through holes 3.

[0027] To ensure sufficient assembly depth for the outer support rod 4, and to prevent spatial collision and interference between the end of the outer support rod 4 and the sheath core 10 located at the center of the tip head 1, the radial extension depth of the tip head radial through hole 3 inside the tip head 1 is less than the distance between the outer surface of the tip head 1 and the outer wall of the sheath core locking cavity 2. The six tip head radial through holes 3 are distributed throughout the peripheral space of the sheath core locking cavity 2. A solid material spacer is maintained between the innermost bottom surface of each tip head radial through hole 3 and the side wall of the sheath core locking cavity 2. The sheath core locking cavity 2 occupies the inner center position of the tip head 1 along its central axis, and the six tip head radial through holes 3 are arranged radially around the sheath core locking cavity 2. This spatial avoidance layout ensures that the axial driving force applied by the sheath core 10 to the tip head 1 is evenly distributed and transmitted to the six circumferentially distributed outer support rods 4.

[0028] See attached document Figure 1 and attached Figure 3The outer support rod 4 and the lower support rod 6 are made of a single metal tube, cut and formed from a single piece of nickel-titanium tube. After the cutting process, they are divided into an upper structure consisting of 6 outer support rods 4 and a lower structure consisting of 6 lower support rods 6 in terms of axial spatial distribution.

[0029] The outer support rod 4 is inserted into the outer surface of the tip head 1 and fits tightly against the inner wall of the radial through hole 3 of the tip head, forming an abutment state and completing the fixed connection at the contact position.

[0030] The six lower support rods 6 are located on the side of the outer support rod 4 away from the tip head 1. In their natural state, the middle part of the six lower support rods 6 bends and expands away from the central axis.

[0031] In this embodiment, a conduit 14 is sleeved on the outer side of the sheath core 10. The ends of each lower support rod 6, away from the outer support rod 4, bend and converge towards the central axis, and are collectively fixedly connected to the end surface of the conduit 14 near the tip head 1. The lower support rods 6, fixed to the conduit 14, provide a physical support boundary near the operator. The sheath core 10 slides through the interior of the conduit 14. The outer support rod 4 and the lower support rods 6 form a mechanically constrained connection structure at both ends through the tip head 1 and the end of the conduit 14.

[0032] See attached document Figure 1 and attached Figure 2 A cutting node 5 is integrally formed at the midpoint of the axial direction between the outer support rod 4 and the lower support rod 6. The cutting node 5 is a continuous nickel-titanium alloy solid material transition zone, avoiding flexible fractures caused by discrete connections. The V-shaped bifurcated configuration of the cutting node 5 serves as a force transmission center, transferring the axial deformation energy from the outer support rod 4 to the lower support rod 6. The cutting node 5 improves the fatigue life of the support and ensures radial linkage between the outer support rod 4 and the lower support rod 6 during diameter adjustment, matching the anatomical structure.

[0033] Six outer support rods 4 bend and expand away from the central axis between the tip head 1 and the cutting node 5, forming the upper structure. Six lower support rods 6 bend and expand away from the central axis between the cutting node 5 and the end of the conduit 14, forming the lower structure. In a natural state without external axial force applied to the sheath core 10, the upper structure has a first outer diameter perpendicular to the central axis, and the lower structure has a second outer diameter perpendicular to the central axis. The value of the first outer diameter is smaller than the value of the second outer diameter. The radial expansion dimension of the upper structure formed by the outer support rods 4 is smaller than the radial expansion dimension of the lower structure formed by the lower support rods 6, resulting in an asymmetrical three-dimensional spatial profile where the front end expands less and the rear end expands more.

[0034] See attached document Figure 2 An upper electrode 7 is fitted onto the outer surface of the outer support rod 4. A lower electrode 8 is fitted onto the outer surface of the lower support rod 6. Electrode mounting grooves 9 are formed on the outer and outer surfaces of both the outer and lower support rods 4 and 6. The upper electrode 7 is fixedly fitted into the electrode mounting groove 9 of the outer support rod 4. The lower electrode 8 is fixedly fitted into the electrode mounting groove 9 of the lower support rod 6.

[0035] The radial depth of the inward recess in the electrode mounting groove 9 is equal to the wall thickness of the annular solid of the upper electrode 7, and simultaneously equal to the wall thickness of the annular solid of the lower electrode 8. The electrode mounting groove 9 is formed along the axial extension of the outer support rod 4 or the lower support rod 6. Metal solid limiting steps, perpendicular to the outer surface of the outer support rod 4 or the lower support rod 6, are formed on both end faces of the electrode mounting groove 9 in the axial direction. These metal solid limiting steps restrict the sliding displacement of the upper electrode 7 and the lower electrode 8 in the axial direction, preventing them from detaching from the outer support rod 4 and the lower support rod 6.

[0036] The radial depth of the electrode mounting groove 9 is equal to the wall thickness of the annular solid of the upper electrode 7 and the lower electrode 8, respectively, so that the outermost surfaces of the upper electrode 7 and the lower electrode 8 are flush with the surfaces of the outer support rod 4 and the lower support rod 6, forming the same smooth extension surface. When entering the blood vessel and contacting the inner wall of the blood vessel, the flush surface prevents the protruding edges from damaging the inner wall tissue of the blood vessel.

[0037] See attached document Figure 1 Appendix Figure 3 and attached Figure 4 Six upper electrodes 7 are distributed in the axial central region of the six outer support rods 4. The six upper electrodes 7 form a first annular ablation array around the central axis in three-dimensional space. The spatial diameter of the first annular ablation array corresponds to the first outward expansion outer diameter dimension.

[0038] A total of 12 lower-layer electrodes 8 are distributed on the outwardly expanding arc-shaped segments of the 6 lower-layer support rods 6. These 12 lower-layer electrodes 8 form a double-layered second annular ablation array around the central axis in three-dimensional space. The spatial diameter of the second annular ablation array corresponds to the outwardly expanding second outer diameter. Because the second outer diameter of the lower layer is larger than the first outer diameter of the upper layer, the radial coverage of the second annular ablation array is greater than that of the first annular ablation array.

[0039] During mapping and ablation for paroxysmal atrial fibrillation, Tip 1 is advanced to the location of the pulmonary vein corresponding to the heart. The first annular ablation array is positioned axially on the side of the second annular ablation array closest to Tip 1. The upper electrode 7 on the outer support rod 4 has a smaller radial dimension and is positioned deep within the smaller pulmonary vein orifice region, adhering to the inner wall of the pulmonary vein orifice. The lower electrode 8 on the lower support rod 6 has a larger radial dimension and is positioned within the larger pulmonary vein vestibule region, adhering to the inner wall of the pulmonary vein vestibule. The double-layer distribution structure formed by the upper electrode 7 and the lower electrode 8 matches the anatomical span from the pulmonary vein orifice to the pulmonary vein vestibule in terms of axial depth and radial expansion. The spatial spacing between the first and second annular ablation arrays in the axial and radial directions constitutes the geometric constraints for synchronously covering the pulmonary vein orifice region and the pulmonary vein vestibule region. When the upper electrode 7 and the lower electrode 8 are in contact with the corresponding inner wall tissue, the electrode array forms a continuous loop in a single axial position targeting the circumference of the pulmonary vein orifice and the circumference of the pulmonary vein vestibule.

[0040] See attached document Figure 5 A loader 11 is fitted over the outer side of the conduit 14. The loader 11 is a tubular solid structure. An annular receiving cavity 12 is defined between the inner wall surface of the loader 11 and the outer surface of the sheath core 10 and the conduit 14.

[0041] During storage, simultaneously pull the conduit 14 and sheath 10 away from the tip head 1, or push the loader 11 towards the tip head 1. The edge of the loader 11 near the tip head 1 contacts the outer surface of the lower support rod 6. As the loader 11 undergoes axial relative sliding displacement, the inner wall of the loader 11 continuously presses against the lower support rod 6 and the outer support rod 4 towards the central axis.

[0042] Under the radial constraint force at the edge of the loader 11, the lower stent 6 and the outer stent 4 undergo centripetal elastic deformation. The outer stent 4 and the lower stent 6 then enter the annular receiving cavity 12 inside the loader 11. The inner wall of the loader 11 restricts the radial expansion of the stent. After fully entering the annular receiving cavity 12, the six outer stents 4 and the six lower stents 6 retract from their outward expansion, presenting a parallel, straight, and contracted state against the outer surface of the sheath core 10. This straight contraction forcibly compresses the maximum radial dimension within the inner diameter of the annular receiving cavity 12. The annular receiving cavity 12 inside the loader 11 provides a smooth outer protective boundary for the advancement and withdrawal of the stent from the blood vessel.

[0043] See attached document Figure 3 and attached Figure 4After being released from inside the loader 11 and in the deployed state, the sheath core 10 achieves various shape switching through axial displacement. When fusiform positioning is required, the sheath core 10 is pushed away from the end of the catheter 14. The sheath core 10 drives the tip head 1 to move synchronously away from the end of the catheter 14, increasing the spatial span between the tip head 1 and the end of the catheter 14, thereby directly applying axial tensile force to the outer support rod 4.

[0044] The outer support rod 4 undergoes elastic deformation under axial tensile force. The outer support rod 4 transitions from an outwardly expanding, bent state to a more straight, tensile state, becoming taut. The mechanical force generated by the tension on the outer support rod 4 is transmitted to the lower support rod 6 through the cutting node 5. Since the lower support rod 6 is fixedly connected to the conduit 14 and thus constrained, it undergoes synchronous axial tensile deformation under the traction of the cutting node 5.

[0045] Under axial tensile deformation, the outer support rod 4 and the lower support rod 6 converge towards the central axis. The expansion diameter formed by the outer support rod 4 and the lower support rod 6 decreases synchronously. The overall three-dimensional envelope contour presents a spindle shape with smaller diameters at both ends and a slightly larger diameter in the middle. The spindle shape reduces the radial dimension. In the spindle shape, it can enter the relatively small pulmonary vein orifice for pre-ablation anatomical positioning. As the displacement of the sheath core 10 changes, the tilt angle of the outer support rod 4 and the lower support rod 6 changes accordingly, thereby achieving continuous adjustment of the spindle diameter.

[0046] See attached document Figure 1 To be continued Figure 4 When performing ablation on the pulmonary vein vestibule region, the sheath core 10 is pulled towards the end of the catheter 14. The axial pulling force generated by the sheath core 10 drives the tip 1 to retract synchronously towards the end of the catheter 14, reducing the axial spatial distance between the tip 1 and the end of the catheter 14, thereby applying an axial compressive force to the outer stent rod 4.

[0047] Under axial compressive force, the outer support rod 4 undergoes elastic deformation, expanding outwards. Spatially, the outer support rod 4 exhibits radial displacement away from the central axis, resulting in an increased expansion diameter. The axial pressure applied by the Tip head 1 is transmitted to the cutting node 5 via the outer support rod 4, and further transmitted to the lower support rod 6 via the cutting node 5. Because the lower support rod 6 is fixedly connected to the end of the conduit 14, the axial position of the end of the conduit 14 remains fixed.

[0048] Under the axial pressure transmitted from the cutting node 5, the lower support rod 6 undergoes bending deformation. The lower support rod 6 expands to its maximum extent radially away from the central axis. The outer support rod 4 and the lower support rod 6 extend outward together under strong axial compression, resulting in a decrease in overall axial height and an increase in maximum radial diameter. The outer support rod 4 and the lower support rod 6 form a flattened, large-diameter expanded shape, i.e., a petal-like shape adhering to the wall.

[0049] In the petal-like apposition configuration, the maximum outer diameter of the lower support rod 6 is greater than the second outer diameter in its natural state. At this time, the lower electrode 8 on the lower support rod 6 expands outwards as the lower support rod 6 expands. The flattened petal-like apposition configuration with its large diameter increases the contact area and pressure between the lower electrode 8 and the pulmonary vein vestibule wall tissue, thus meeting the ablation requirements of large anatomical sites. By adjusting the pull-back displacement of the sheath core 10 towards the end of the catheter 14, the radial expansion degree of the outer support rod 4 and the lower support rod 6 can be controlled, achieving quantitative adjustment of the diameter of the petal-like apposition configuration.

[0050] See attached document Figure 1 -Appendix Figure 5 The mechanical deformation characteristics of the outer stent 4 and the lower stent 6 directly correspond to the anatomical adaptation requirements during the treatment of paroxysmal atrial fibrillation.

[0051] During positioning and ablation at the ostium, the sheath core 10 is pushed into a spindle shape. The radial dimensions of both the outer support rod 4 and the lower support rod 6 in this spindle shape shrink synchronously, allowing the tip 1 to penetrate smoothly into the relatively small pulmonary vein ostium. The outer support rod 4, in its spindle shape, contacts the inner wall tissue of the pulmonary vein ostium. The upper electrode 7 is adjusted radially along with the outer support rod 4 to match the anatomical diameter of the pulmonary vein ostium.

[0052] During ablation of the vestibule and pulmonary vein, the sheath core 10 is pulled to transform into a petal-like attachment shape. The lower support rod 6 expands radially away from the central axis under axial pressure. The flat, large-diameter profile formed by the lower support rod 6 covers the anatomical area of ​​the pulmonary vein vestibule. Based on the elastic deformation characteristics of the lower support rod 6, it can adaptively bend according to the geometry of the concave and convex surfaces of the pulmonary vein vestibule during radial expansion. The lower electrode 8 adheres tightly to the inner wall tissue surface of the pulmonary vein vestibule along with the lower support rod 6.

[0053] The axial stepped distribution structure formed by the outer support rod 4 and the lower support rod 6 in space constitutes the basis for achieving single-stage dual-zone ablation. The upper electrode 7 on the outer support rod 4 corresponds to the pulmonary vein orifice. The lower electrode 8 on the lower support rod 6 corresponds to the pulmonary vein vestibule. Through a single mechanical adjustment by manipulating the sheath core 10, the upper electrode 7 and the lower electrode 8 simultaneously achieve a state of contact with their respective anatomical regions. The electrode array formed by the upper electrode 7 and the lower electrode 8 simultaneously achieves potential isolation of the circumferential regions of the pulmonary vein orifice and the circumferential regions of the pulmonary vein vestibule without changing the axial position of the catheter 14 end. The first annular ablation array and the second annular ablation array generate synchronous radial displacement through mechanical linkage. Driven by the same displacement of the sheath core 10, the upper electrode 7 and the lower electrode 8 establish stable electrical contact interfaces at the pulmonary vein orifice and the pulmonary vein vestibule, respectively.

[0054] Working principle: The operator applies an axial pushing or pulling force along the central axis to the sheath core 10, causing the tip head 1 to move synchronously along the central axis. When the tip head 1 moves forward or backward, it transmits traction or compression force to the outer support rod 4, which is inserted into and fixed inside the radial through hole 3 of the tip head. After being subjected to force, the outer support rod 4 transmits the mechanical force to the cutting node 5. The end of the lower support rod 6 away from the outer support rod 4 is in a fixed and constrained state, and the cutting node 5 transmits the mechanical force of the outer support rod 4 unidirectionally to the lower support rod 6. The outer support rod 4 and the lower support rod 6 undergo synchronous mechanical deformation under the drive of the same power source, forming a load transmission path that diffuses from the center to the periphery.

[0055] During the storage and withdrawal phases, the loader 11 slides relative to the tip head 1, with the edge of the loader 11 near the tip head 1 contacting the outer surfaces of the lower support rod 6 and the outer support rod 4. The inner wall of the loader 11 continuously applies pressure towards the central axis, forcibly overcoming the outward bending and expansion of the lower support rod 6 and the outer support rod 4. The lower support rod 6 and the outer support rod 4 contract towards the central axis, sliding as a whole into the annular cavity 12 defined by the inner wall of the loader 11 and the outer surface of the sheath core 10. Inside the annular cavity 12, the lower support rod 6 and the outer support rod 4 transform into a straight, converging state parallel to and conforming to the outer surface of the sheath core 10.

[0056] After being released from inside the loader 11, the sheath core 10 is pushed away from the end of the catheter 14. The tip 1 moves forward with the sheath core 10 and applies a tensile force to the outer support rod 4. The outer support rod 4, under tension, straightens. The tensile force of the outer support rod 4 is transmitted to the lower support rod 6 through the cutting node 5. The lower support rod 6 undergoes axial tensile deformation along with the outer support rod 4. The outer support rod 4 and the lower support rod 6 converge towards the central axis, forming a spindle shape with smaller diameters at both ends and a larger diameter in the middle. The operator pushes the tip 1, with its reduced radial dimensions, into the pulmonary vein orifice. The outer support rod 4 drives the upper electrode 7 to adjust its radial position, and the first annular ablation array composed of the upper electrodes 7 establishes adhesion with the inner wall tissue of the pulmonary vein orifice.

[0057] When operating on the large pulmonary vein vestibule region, the sheath core 10 is pulled towards the end of catheter 14, causing the tip 1 to retract and apply a compressive force to the outer stent 4. The outer stent 4 moves under pressure away from the central axis, and the force is transmitted to the lower stent 6 via the cutting node 5. The lower stent 6 undergoes bending deformation and expands away from the central axis, transforming the outer stent 4 and lower stent 6 into a flattened, large-diameter, expanded petal-like shape adhering to the vessel wall. The lower stent 6 bends according to the shape of the vessel surface, causing the lower electrode 8 to spread outwards. The metal solid limiting steps at both ends of the electrode mounting groove 9 restrict the axial sliding of the upper electrode 7 and lower electrode 8, preventing them from detaching. The outermost surface of the upper electrode 7 is on the same plane as the outermost surface of the outer support rod 4, and the outermost surface of the lower electrode 8 is on the same plane as the outermost surface of the lower support rod 6. The second ring ablation array composed of the lower electrodes 8 is attached to the inner wall tissue of the pulmonary vein vestibule, and the upper electrode 7 and the lower electrode 8 synchronously establish an electrical contact interface at the corresponding anatomical position.

Claims

1. An ablation catheter with a double-layer basket support, characterized in that, It includes a tip head (1), an outer support rod (4), a lower support rod (6), and a sheath core (10) that passes through the central axis. The tip head (1) has a sheath core locking cavity (2) opened along the central axis inside. The end of the sheath core (10) is fixedly connected to the inside of the sheath core locking cavity (2). The cylindrical sidewall of the tip head (1) has a tip head radial through hole (3) opened along the central axis. The ends of a total of 6 outer support rods (4) are respectively inserted radially into the inside of a corresponding tip head radial through hole (3). The sheath core (10) is fitted with a catheter (14) on the outside. A total of 6 lower support rods (6) are located on the side of the outer support rod (4) away from the tip head (1). The ends of each lower support rod (6) away from the outer support rod (4) are fixedly connected to the end surface of the catheter (14) near the tip head (1). A cutting node (5) is integrally formed between the outer support rod (4) and the lower support rod (6) at the axial middle position along the central axis.

2. The ablation catheter with a double-layer basket support according to claim 1, characterized in that, The tip head (1) has a top surface, and the tip head (1) has a scratch-resistant rounded corner (13) near the edge of the top surface. The scratch-resistant rounded corner (13) has a smooth arc-shaped transition surface, so that the front end of the tip head (1) forms a structure without sharp edges.

3. The ablation catheter with a double-layer basket support according to claim 1, characterized in that, The six outer support rods (4) bend and expand away from the central axis between the tip head (1) and the cutting node (5), and the six outer support rods (4) together form the upper structure. The six lower support rods (6) bend and expand away from the central axis between the cutting node (5) and the end of the conduit (14), and the six lower support rods (6) together form the lower structure.

4. The ablation catheter with a double-layer basket support according to claim 3, characterized in that, In its natural state without applying an external axial force to the sheath core (10), the upper structure has a first outer diameter perpendicular to the central axis, and the lower structure has a second outer diameter perpendicular to the central axis, wherein the value of the first outer diameter is smaller than the value of the second outer diameter.

5. The ablation catheter with a double-layer basket support according to claim 1, characterized in that, The outer support rod (4) is fitted with an upper electrode (7), and the lower support rod (6) is fitted with a lower electrode (8). Electrode mounting grooves (9) are provided on the outer surface of both the outer support rod (4) and the lower support rod (6). The upper electrode (7) is fixedly fitted inside the electrode mounting groove (9) of the outer support rod (4), and the lower electrode (8) is fixedly fitted inside the electrode mounting groove (9) of the lower support rod (6).

6. The ablation catheter with a double-layer basket support according to claim 5, characterized in that, The radial depth of the inward recess of the electrode mounting groove (9) is equal to the wall thickness of the annular solid of the upper electrode (7), and the radial depth of the inward recess of the electrode mounting groove (9) is equal to the wall thickness of the annular solid of the lower electrode (8). The two end faces of the electrode mounting groove (9) in the axial direction form metal solid limiting steps perpendicular to the outer surface of the outer support rod (4) or the outer surface of the lower support rod (6).

7. An ablation catheter with a double-layer basket support according to claim 5, characterized in that, The six upper electrodes (7) are distributed in the axial middle region of the six outer support rods (4). The six upper electrodes (7) form a first annular ablation array around the central axis in three-dimensional space. A total of 12 lower electrodes (8) are distributed on the arc-shaped segments that expand outward from the six lower support rods (6). The 12 lower electrodes (8) form a second annular ablation array arranged in two layers around the central axis in three-dimensional space.

8. The ablation catheter with a double-layer basket support according to claim 1, characterized in that, The outer side of the conduit (14) is fitted with a loader (11), which is a tubular solid structure. The inner wall of the loader (11) and the outer surface of the sheath (10) and the conduit (14) define an annular receiving cavity (12). The loader (11) is in contact with the outer surface of the lower support rod (6) near the edge of the tip head (1).

9. The ablation catheter with a double-layer basket support according to claim 1, characterized in that, The radial extension depth of the Tip head radial through hole (3) inside the Tip head (1) is less than the distance between the outer surface of the Tip head (1) and the outer wall of the sheath core locking cavity (2). The six Tip head radial through holes (3) are distributed in the outer space of the sheath core locking cavity (2). A solid material spacer structure is maintained between the innermost bottom surface of each Tip head radial through hole (3) and the side wall of the sheath core locking cavity (2).

10. An ablation catheter with a double-layer basket support according to claim 1, characterized in that, The outer support rod (4) and the lower support rod (6) are made of a single metal tube. The cutting node (5) is a continuous nickel-titanium alloy solid material transition zone. The cutting node (5) has a V-shaped bifurcation configuration.

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