Ablation catheter

Abstract

The invention relates to the technical field of medical instruments, in particular to an ablation catheter. Comprising a tube body and a head end, the head end is arranged at the far end of the tube body, a pull rod is connected into the tube body in a sliding mode, and the pull rod is fixed to the head end; the head end can move close to or away from the axis of the pipe body under the action of the pull rod, a plurality of spokes are arranged between the pipe body and the head end, and when the head end moves close to the pipe body, the spokes can be bent in the direction away from the pipe body in the radial direction. The spokes are provided with limiting assemblies which enable deformation of the spokes to be bent according to setting. The catheter is fast in positioning, accurate in head end positioning, capable of achieving one-time ablation and stable in structure.

Description

Technical Field

[0001] This application relates to the technical field of medical devices; in particular, it relates to an ablation catheter. Background Art

[0002] Catheter ablation targeting the isolation of abnormal pulmonary vein electrical signals is the most commonly used method in the treatment of atrial fibrillation. When performing ablation isolation on the circumferential pulmonary veins, the operator needs to perform catheter placement operations to effectively abut the electrode part at the distal end of the ablation catheter against the signal abnormal area, and then perform ablation to achieve effective signal isolation. However, due to the differences in physiological anatomy, the operator often cannot accurately place the ablation catheter in one step. It is necessary to repeatedly adjust the position of the distal end of the catheter to perform the operation of aligning with the pulmonary vein ostium, and it is necessary to repeatedly release energy for ablation, which affects the efficiency of the operation. Summary of the Invention

[0003] To solve the problems existing in the prior art, this application provides an ablation catheter.

[0004] The specific technical solution of this application is as follows:

[0005] 1. An ablation catheter, which includes a catheter body and a distal end. The distal end is arranged at the distal end of the catheter body. A pull rod is slidably connected inside the catheter body, and the pull rod is fixed to the distal end. The distal end can move closer to or away from along the axis of the catheter body under the action of the pull rod. A plurality of spokes are arranged between the catheter body and the distal end. When the distal end moves closer to the catheter body, the spokes will bend radially away from the catheter body.

[0006] A limiting component is arranged on the spoke to make the deformation of the spoke bend according to a set curvature.

[0007] 2. The catheter according to item 1, wherein the spoke includes a first spoke and a second spoke; the first spoke is located at the distal position of the second spoke.

[0008] 3. The catheter according to item 2, wherein the length of the first spoke is less than the length of the second spoke.

[0009] 4. The catheter according to item 3, wherein the bending direction of the first spoke is opposite to the bending direction of the second spoke.

[0010] 5. The catheter according to any one of items 2 to 4, wherein the curvature of the bending of the first spoke is greater than the curvature of the bending of the second spoke.

[0011] 6. The catheter according to item 1, wherein a first strip electrode and a second strip electrode are arranged on the spoke. The first strip electrode is arranged at the distal end of the second strip electrode, and the first strip electrode is arranged at one end position close to the distal end on the spoke.

[0012] 7. The catheter according to item 6, wherein the number of the spokes is 4 to 10.

[0013] 8. The catheter according to item 6, wherein a connecting portion is provided between the first strip-shaped electrode and the second strip-shaped electrode, and the limiting component is connected to the connecting portion.

[0014] 9. The catheter according to item 6, wherein the bending directions of the first strip-shaped electrode and the second strip-shaped electrode are opposite.

[0015] 10. The catheter according to item 9, wherein the bending curvature of the first strip-shaped electrode is greater than that of the second strip-shaped electrode.

[0016] 11. The catheter according to item 6, wherein the distance from the first strip-shaped electrode to the axis of the tube body when unfolded is less than the distance from the second strip-shaped electrode to the axis of the tube body when unfolded.

[0017] 12. The catheter according to item 6, wherein the closest distance between the first strip-shaped electrode and the second strip-shaped electrode is 4 to 10 mm.

[0018] 13. The catheter according to item 12, wherein the closest distance between the first strip-shaped electrode and the second strip-shaped electrode is 6 to 8 mm.

[0019] 14. The catheter according to item 6, wherein when the first strip-shaped electrode is in the unfolded state, the closest distance from the first electrode to the axis of the tube body is 2 to 15 mm.

[0020] 15. The catheter according to item 14, wherein when the first strip-shaped electrode is in the unfolded state, the closest distance from the first electrode to the axis of the tube body is 3 to 8 mm.

[0021] 16. The catheter according to item 15, wherein the farthest distance from the first strip-shaped electrode to the axis of the tube body is 2 to 15 mm.

[0022] 17. The catheter according to item 16, wherein the farthest distance from the first strip-shaped electrode to the axis of the tube body is 7 to 12 mm.

[0023] 18. The catheter according to item 6, wherein when the second strip-shaped electrode is in the unfolded state, the closest distance range from the second electrode to the axis of the tube body is 5 to 20 mm.

[0024] 19. The catheter according to item 18, wherein when the second strip-shaped electrode is in the unfolded state, the closest distance range from the second electrode to the axis of the tube body is 7 to 12 mm.

[0025] 20. The catheter according to item 19, wherein the farthest distance range from the second electrode to the axis of the tube body is 5 to 20 mm.

[0026] 21. The catheter according to item 20, wherein the maximum distance from the second electrode to the axis of the tube body ranges from 10 to 15 mm.

[0027] 22. The catheter according to item 1, wherein the limiting assembly includes a limiting film; a plurality of limiting films are provided, and the limiting films are all arranged between two adjacent spokes, and both ends of the limiting film are respectively connected to the adjacent spokes.

[0028] 23. The catheter according to item 1, wherein the limiting film is a polymer film made of an insulating material.

[0029] 24. The catheter according to item 1, wherein the limiting assembly includes a metal wire, and the metal wire is arranged between two adjacent spokes; both ends of the metal wire are respectively connected to the spokes.

[0030] 25. The catheter according to item 24, wherein the metal wire is a highly elastic metal wire.

[0031] 26. The catheter according to item 24, wherein the number of metal wires respectively arranged between every two adjacent spokes is one or more than two, and the metal wires are arranged to avoid the first strip electrode and the second strip electrode.

[0032] 27. The catheter according to item 26, when the number of metal wires arranged between two adjacent spokes is two, the two metal wires are respectively fixed to the connecting part and the proximal end of the second strip electrode.

[0033] 28. The catheter according to item 8, wherein the limiting assembly includes a limiting flat wire, a plurality of limiting flat wires are provided, one end of the limiting flat wire is fixedly connected to the pull rod, and the other end of the limiting flat wire is fixed to the spoke; the limiting flat wire is connected to the connecting part.

[0034] 29. The catheter according to item 28, wherein the limiting assembly further includes an auxiliary flat wire arranged between the spoke and the pull rod, and one end of the auxiliary flat wire far from the spoke is fixed to one end of the limiting flat wire close to the pull rod; or one end of the limiting flat wire far from the spoke is fixed to the pull rod.

[0035] 30. The catheter according to item 29, wherein one end of the auxiliary flat wire far from the pull rod is fixed to the spoke, and the auxiliary flat wire is fixed to the side of the spoke close to the proximal end.

[0036] 31. The catheter according to item 30, preferably, the auxiliary flat wire is fixedly connected to the side of the proximal end of the second strip electrode.

[0037] 32. The catheter according to item 1, wherein the minimum distance between two adjacent spokes is 4 to 10 mm.

[0038] 33. The catheter according to item 32, wherein the minimum distance between two adjacent spokes is 6-8 mm.

[0039] 34. The catheter according to item 1, wherein a first magnetic sensor is provided on the head end, and a second magnetic sensor is provided at a position near the spoke at the distal end of the tube body.

[0040] Beneficial effects

[0041] During use, the ablation catheter of the present application realizes reciprocating movement of the head end through a pull rod, and at the same time drives the expansion and closing of the spokes. The spokes can be bent unidirectionally. After the spokes are expanded, they are in a papillary shape. The pull rod is a hollow structure and can pass through a guide wire, so that the ablation catheter can be quickly positioned and easily enter the pulmonary vein during use, and rapid apposition can be achieved.

[0042] The papillary spokes are respectively provided with a first magnetic sensor at the distal position and a second magnetic sensor at the proximal end. The first sensor and the second sensor can be used together with a three-dimensional system to further display the position of the ablation catheter or the spokes in the heart cavity in real time, so as to achieve precise positioning.

[0043] A first strip electrode and a second strip electrode are provided on the spoke to realize a double-layer electrode arrangement. The first strip electrode near the head end is the first layer electrode, and the second strip electrode is the second layer electrode. The expansion amplitude of the first strip electrode and the second strip electrode can be adjusted by operating the pull rod.

[0044] Among them, the diameter range of the first layer electrode is 12-17 mm to adapt to pulmonary veins of different sizes; the second layer electrode is linked with the first layer electrode, and the outer diameter after expansion is 20-25 mm to assist in apposing the circumferential pulmonary vein ostium;

[0045] The area scanned by the first strip electrode and the second strip electrode rotating around the axis of the tube body is a surface area, which has a larger contact range and higher ablation efficiency compared with the traditional point contact area.

[0046] The first strip electrode and the second strip electrode are connected in series by means of the shape memory alloy of the spoke. The interval between the first strip electrode and the second strip electrode is 4-6 mm, and the interval between two adjacent spokes is 6 mm-8 mm, reducing the concentration of voltage energy.

[0047] The double-layer electrodes of the first strip electrode and the second strip electrode can also realize double-loop isolation of the pulmonary vein and the circumferential pulmonary vein ostium, improving the ablation effect; the spokes are connected to each other by a polymer film or other fixing methods to fix the spoke spacing and reduce the swing of adjacent strip electrodes.

[0048] In the present application, the catheter has rapid positioning, accurate head end positioning, single ablation, and stable structure. Description of the drawings

[0049] Figure 1 It is a schematic diagram of the catheter structure in Embodiment 1 of the present application;

[0050] Figure 2 It is a schematic diagram of the tissue ablation by the catheter in Embodiment 1 of the present application;

[0051] Figure 3 It is a cross-sectional view of the tissue ablation by the catheter in Embodiment 1 of the present application;

[0052] Figure 4 It is a schematic diagram of the catheter structure in Embodiment 2 of the present application;

[0053] Figure 5 It is in the present application Figure 2 Cross-sectional view A-A therein;

[0054] Figure 6 It is a schematic diagram of the catheter structure in Embodiment 3 of the present application;

[0055] Figure 7 It is in the present application Figure 6 Cross-sectional view C-C therein;

[0056] Figure 8 It is in the present application Figure 7 Partial enlarged view of part A therein.

[0057] In the figure, 1, catheter body; 11, pull rod; 2, head end; 3, spoke; 30, connecting part; 31, limiting film; 32, wire; 33, limiting flat wire; 34, auxiliary flat wire; 4, first strip electrode; 5, second strip electrode; 6, first magnetic sensor; 7, second magnetic sensor; 8, guide wire; 9, tissue. Detailed implementation manners

[0058] The present application will be described in detail below. Although specific embodiments of the present application are shown, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present application can be more thoroughly understood and the scope of the present application can be completely conveyed to those skilled in the art.

[0059] It should be noted that certain terms are used in the description and claims to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. The description and claims of this specification do not distinguish components by the difference in nouns, but by the difference in the functions of the components. For example, the terms "comprising" or "including" mentioned throughout the specification and claims are open-ended terms, so they should be interpreted as "including but not limited to". The subsequent description in the specification is the preferred embodiment for implementing the present application, but the description is for the purpose of the general principles of the specification and is not used to limit the scope of the present application. The protection scope of the present application shall be determined by what is defined in the appended claims.

[0060] Reference Figure 1 and Figure 2 , the present application provides an ablation catheter. Among them, it includes a catheter body 1 and a distal end 2. The distal end 2 is arranged at the distal end of the catheter body 1. A pull rod 11 is slidably connected inside the catheter body 1, and the pull rod 11 is fixed to the distal end 2; the distal end 2 can move closer to or away from along the axis of the catheter body 1 under the action of the pull rod 11. A plurality of spokes 3 are arranged between the catheter body 1 and the distal end 2. When the distal end 2 moves closer to the catheter body 1, the spokes 3 will bend radially away from the catheter body 1;

[0061] Reference Figure 3 , Figure 4 and Figure 6 , a limiting component is arranged on the spoke 3 to make the deformation of the spoke 3 bend according to a set curvature.

[0062] In the field of interventional medicine, the end close to the operator is defined as "proximal end", and the end far from the operator is defined as "distal end". For a long object, the direction parallel to its length extension direction is defined as "axial direction"; for an object with a circular cross-section, the direction around its axial direction is defined as "circumferential direction". For a cylindrical object, its extension direction is defined as "axial direction", and the radius direction of the circular cross-section is defined as "radial direction". At the same time, in the present application, the direction away from the axis is defined as outwards, and the direction close to the central axis is defined as inwards.

[0063] Reference Figure 2 and Figure 3 , when ablating the tissue 9, it is necessary to transport the distal end 2 to the target area, and the distal end 2 can play a role in positioning and guiding. The catheter body 1 is a long tubular structure, and the catheter body 1 is used to transport the distal end 2. The catheter body 1 transports the distal end 2 to the target area, and then the distal end 2 ablates the tissue 9 in the target area.

[0064] Reference Figure 2 and Figure 3, the spoke 3 is located at the proximal end of the head end 2. After the head end 2 is transported into the human tissue 9 by the tube body, the pull rod 11 can be pulled toward the proximal end, and then the pull rod 11 drives the head end 2 to move toward the proximal end. At this time, the head end 2 approaches the direction of the tube body 1, so the spoke 3 is compressed by the tube body 1 and the head end 2, and the two ends of the spoke 3 are close to each other, so that the body of the spoke 3 bends outward, increasing the radial size of the spoke 3, so that the spoke 3 can contact the human tissue 9.

[0065] refer to Figure 2 and Figure 3 After the spokes 3 are deployed in the target area of the human tissue 9, they will come into contact with the human tissue 9, and the deployed spokes 3 have a larger radial size and can come into contact with the tissue 9 in a ring shape, thereby increasing the contact range between the spokes 3 and the tissue 9. The spokes 3 are then used to ablate the tissue 9, which has a higher ablation efficiency, reduces the number of ablations and the ablation time, thereby shortening the time of the ablation operation and reducing the possibility of surgical dangers.

[0066] refer to Figure 1 and Figure 3 The limit assembly is used to limit the bending of the spoke 3. When the spoke 3 bends under the compression of the head end 2 and the tube body 1, the spoke 3 will bend in different shapes due to the structural strength of the spoke 3 itself. Under normal circumstances, the spoke 3 will present a smooth curve and be completely circular or elliptical. When this shape is in contact with the tissue 9, the spoke 3 and the tissue 9 will only contact in the tangential direction of the spoke 3 or the tangential direction of the surface of the tissue 9. If the contact area or contact range between the human tissue 9 and the spoke 3 is to be increased, it is necessary to apply pressure to the spoke 3 to deform the spoke 3 and / or the human tissue 9 to achieve the contact between the spoke 3 and the tissue 9. This can easily cause damage to the human tissue 9. Furthermore, the deformation of the spoke 3 caused by squeezing is difficult to control, and the ablation of the human tissue 9 by the spoke 3 is more likely to cause additional damage. Increase the risk of complications for patients.

[0067] refer to Figure 2 Therefore, in the present application, a limiting component is used to limit the shape of the spoke 3. When the spoke 3 is unfolded, it will form a specific preset shape. For example, in a specific embodiment, the spoke 3 is unfolded under the action of the limiting component and presents a conical shape similar to the pulmonary vein orifice, so that the outer edge of the spoke 3 can fit the pulmonary vein orifice under normal conditions. The force of the spoke 3 when fitting to the human tissue 9 is effectively reduced. Similarly, in different use environments or different structures of human tissue 9, the spoke 3 can be preset into different shapes that fit therewith. In addition, the shape and size of the spoke 3 can also be different for use in patients of different ages or body shapes.

[0068] refer to Figure 5The pull rod 11 is a hollow structure, and a guide wire 8 is arranged at the center of the pull rod 11. The guide wire 8 is used to guide the pull rod 11 and the head end 2. When the tube body 1 and the head end 2 enter the human body, the guide wire 8 is first used to guide the head end 2, and then the head end 2 and the tube body 1 are deeply inserted into the human body along the direction of the guide wire 8. The strength of the guide wire 8 is relatively small, so it can reduce the puncture of the tissue 9.

[0069] refer to Figure 1 The spoke 3 includes a first spoke and a second spoke; the first spoke is located at the distal end of the second spoke.

[0070] refer to Figure 1 and Figure 4 The spokes 3 also include a connecting spoke 3 located between the first spoke and the second spoke and a third spoke located at the proximal end of the second spoke.

[0071] The third spoke is located at the most proximal position, and the third spoke is connected to the tube body 1, and the distal end of the third spoke is connected to the second spoke. The connecting spoke 3 is connected to the distal position of the second spoke, and the distal end of the connecting spoke 3 is connected to the first spoke, and the distal end of the first spoke is connected to the end.

[0072] refer to Figure 1 and Figure 3 When the spokes 3 are used to contact the tissue 9, the first spoke and the second spoke at the distal position can bend and present a shape similar to the structure of the pre-contacted tissue 9, thereby achieving the first spoke and the second spoke to be in contact with the tissue 9, so that the force exerted by the first spoke and the second spoke on the tissue 9 when in contact with the tissue 9 is reduced, thereby reducing the possibility of causing damage to the human tissue 9.

[0073] refer to Figure 1 and Figure 3 , and the third spoke at the proximal position plays a supporting role. The first spoke and the second spoke at the distal position are attached to the tissue 9, which will generate a reaction force toward the proximal direction, and the third spoke can provide a supporting force to reduce the deformation of the first spoke and the second spoke due to the force toward the proximal end. Therefore, the supporting force provided by the third spoke can make the first spoke and the second spoke and the tissue 9 more closely attached.

[0074] refer to Figure 1 In one embodiment, the length of the first spoke is less than the length of the second spoke.

[0075] The first spoke is located at the distal end, and the length of the first spoke is set to be shorter, so that the distance that the first spoke can bend outward when bending is smaller, thereby reducing the radial dimension of the first spoke after bending, so that the first spoke can enter the human tissue 9 of smaller size.

[0076] Reference Figure 2 The second spoke located at the proximal position is arranged in a structure with a longer length. Therefore, the second spoke can be bent again after the first spoke is bent, and extend a longer distance in the radial direction, so that the second spoke can be in contact with a larger range of tissue 9.

[0077] By using the first spoke to enter into the tissue 9 with a smaller size and using the second spoke to make extensive contact with the tissue 9, it is possible to achieve large-scale ablation of the interior and surface of the tissue 9 in one go, thereby reducing the ablation area of the tissue 9 and improving the ablation efficiency.

[0078] Reference Figure 1 and Figure 4 The bending direction of the first spoke is opposite to that of the second spoke.

[0079] In a specific embodiment, the bending direction of the first spoke is concave (not shown in the figure), and the bending direction of the second spoke is convex.

[0080] The concave first spoke enables the size of the first spoke at the distal position to be smaller, so that the first spoke can enter into the interior of the tissue 9 with a smaller size. And the convex second spoke is more likely to come into contact with the tissue 9, which helps to make the second spoke fit more closely with the tissue 9.

[0081] Reference Figure 1 and Figure 4 In a specific embodiment, the bending direction of the first spoke is convex, and the bending direction of the second spoke is concave. At the same time, the transition part between the first spoke and the second spoke presents a smooth curved surface that changes from convex to concave.

[0082] Reference Figure 3 Generally, the human tissue 9 is in a shape with a diameter gradually decreasing at the connection port. And due to the soft characteristics of the human tissue 9, in most cases, the connection port is a smooth curved surface for transition, which is similar to the shape of the first spoke and the second spoke near the middle position in this application.

[0083] Therefore, in this application, reference Figure 2 and Figure 3, the first spoke is set to be convex and the second spoke is set to be concave. Therefore, the distal position of the first spoke presents a convex shape at the distal end, reducing the sharpness at the distal end, and thus reducing the possibility of causing harm to the tissue 9. The connection between the first spoke and the second spoke and the second spoke present a concave shape, so that the shapes of the connection positions of the first spoke and the second spoke with the human tissue 9 are more similar. When the first spoke and the second spoke are in contact with the human tissue 9, the acting forces of the first spoke and the second spoke on the human tissue 9 are reduced, so as to reduce the possibility of the tissue 9 being damaged by the first spoke and the second spoke.

[0084] The bending directions of the first spoke and the second spoke are set to be opposite, so that the shapes of the first spoke and the second spoke at the interface position with the human tissue 9 are more similar, thereby reducing the acting forces and harm of the first spoke and the second spoke on the human tissue 9. At the same time, the convex bending of the first spoke can achieve the effect of reducing the sharpness at the distal end and reducing the harm to the human tissue 9.

[0085] Reference Figure 1 and Figure 4 , the curvature of the bending of the first spoke is greater than the curvature of the bending of the second spoke.

[0086] The first spoke is located at the distal position of the second spoke. The greater the bending amplitude of the first spoke, the closer the first spoke is to the radial length within a limited length, so that the first spoke can enter into the tissue 9 with a smaller size.

[0087] Reference Figure 1 and Figure 3 , in addition, when the first spoke is convex, the first spoke with a larger bending amplitude reduces the radial size of the first spoke while also controlling the sharpness of the first spoke within a smaller range. Therefore, setting the first spoke to be convex with a larger bending amplitude further improves the application range of the first spoke.

[0088] Reference Figure 1 and Figure 4 , the second spoke with a longer length is set to have a smaller curvature structure, so the shape of the second spoke is more inclined to a straight line shape, reducing the sharpness of the second spoke.

[0089] Reference Figure 1 and Figure 4, in addition, when the first spoke is convex and the second spoke is concave, when the second spoke extends towards the proximal end, the second spoke with a small curvature that is nearly straight can extend along the tangent direction of the end of the first spoke. This increases the smoothness at the connection of the first spoke and the second spoke. On the other hand, due to the relatively long length of the second spoke, in order to make the proximal end of the second spoke connect more smoothly with the third spoke located at the proximal end after bending, the bending curvature of the second spoke is set within a small range. This improves the smoothness at the connection of the second spoke and the third spoke, thereby reducing the likelihood of damage to the tissue 9 caused by the second spoke and the third spoke.

[0090] Reference Figure 1 and Figure 4 , in addition, controlling the bending curvature of the second spoke within a small range is also to reduce the occurrence of a tip at the bend of the relatively long second spoke due to excessive bending. The second spoke with a small bending curvature helps to improve the overall smoothness of the first spoke, the second spoke, and the third spoke.

[0091] Reference Figure 1 and Figure 4 , on the spoke 3, a first strip electrode 4 and a second strip electrode 5 are provided. The first strip electrode 4 is provided at the distal end of the second strip electrode 5, and the first strip electrode 4 is provided at a position on the spoke 3 near the head end 2.

[0092] Reference Figure 1 and Figure 4 , in a specific embodiment, the first strip electrode 4 is provided on the first spoke; and the first strip electrode 4 is located at a position on the first spoke near the distal end. Since the distal end of the first spoke is fixed to the head end 2, the distal end position of the first spoke is inside the pulmonary vein or other tissues in the bent state and does not contact the human tissue 9. Therefore, the first strip electrode 4 is provided at a position on the first spoke near the proximal end, so that the first strip electrode 4 can contact the human tissue 9 over a larger range, enabling the first strip electrode 4 to ablate the human tissue 9 in contact with it.

[0093] Reference Figure 1 and Figure 4 , in another specific embodiment, the first strip electrode 4 is provided at the proximal end of the first spoke and the distal end of the second spoke. The first strip electrode 4 covers the first spoke, the second spoke, and their connection, and the bending directions of the first spoke and the second spoke are opposite. Therefore, the first strip electrode 4 presents a smooth transition shape with a gradually changing bending direction, and the first strip electrode 4 is on the first spoke and the second spoke

[0094] Reference Figure 1 and Figure 4, the second strip electrode 5 extends from the distal end of the second spoke towards the proximal end.

[0095] In a specific embodiment, referring to Figure 1 and Figure 4 , the second strip electrode 5 extends to the proximal end of the second spoke. That is, the second strip electrode 5 covers the second spoke. Therefore, when the second spoke is abutted against the human tissue 9, especially at the position of the tissue 9 structure, the bent shape of the second spoke is similar to the tissue 9 structure and thus can achieve abutting contact. At this time, the second strip electrode 5 can be in contact with the tissue 9 entirely, and then ablate the tissue 9. The utilization rate of the second strip electrode 5 is improved.

[0096] In another specific embodiment, referring to Figure 1 and Figure 4 , the second strip electrode 5 extends to the distal position of the third spoke. In this embodiment, it means that when the second strip electrode 5 extends towards the proximal end, it crosses the position of the third spoke that is radially farthest from the axis of the tube body 1, that is, the second strip electrode 5 covers the radially outermost position of the spoke 3.

[0097] Referring to Figure 1 and Figure 4 , when using the second strip electrode 5 to ablate the tissue 9, the coverage area of the second strip electrode 5 on the spoke 3 exceeds the radially farthest distance of the spoke 3. Therefore, after the spoke 3 enters the human tissue 9, the positions where the front end of the spoke 3 can contact the tissue 9 can all be ablated by the second strip electrode 5. In particular, when the spoke 3 enters the tubular tissue 9, the radially distal edge position of the spoke 3 contacts the inside of the tissue 9. At this time, the second strip electrode 5 can be used to ablate the tissue 9. The applicability of the second strip electrode 5 to ablate the tissue 9 is improved.

[0098] In another specific embodiment, the second spoke extends to the proximal position of the third spoke (not shown in the figure). That is, the second strip electrode 5 completely covers the second spoke and the third spoke. Setting the second strip electrode 5 in such a large coverage area greatly increases the area of the spoke 3 available for ablation. Therefore, when using the second strip electrode 5 and the first strip electrode 4 to ablate the tissue 9, only the spoke 3 needs to be abutted against the tissue 9 to be ablated for ablation. On the other hand, the area of the second strip electrode 5 is greatly increased, thereby reducing the pressure of the second strip electrode 5 on the human tissue 9 when abutting against the tissue 9, and thus reducing the damage to the tissue 9.

[0099] Referring to Figure 1 and Figure 4 , the bending directions of the first strip electrode 4 and the second strip electrode 5 are opposite.

[0100] The first strip electrode 4 and the second strip electrode 5 are both used for ablating the tissue 9. The first strip electrode 4 and the second strip electrode 5 need to be in contact with the tissue 9, and gaps between them and the tissue 9 should be avoided to ensure the ablation effect on the tissue 9. Therefore, the first strip electrode 4 and the second strip electrode 5 are arranged on the outer - side surfaces of the first spoke and the second spoke, enabling the first strip electrode 4 and the second strip electrode 5 to be in contact with the tissue 9.

[0101] Reference Figure 1 and Figure 4 , since the length of the second strip electrode 5 is relatively long and the bending shape of the second strip electrode 5 has variability, here it means that the bending direction of the second strip electrode 5 near the end of the first strip electrode 4 is opposite to the bending direction of the first strip electrode 4. This enables a relatively smooth transition between the first strip electrode 4 and the second strip electrode 5. At the same time, it also enables the first strip electrode 4 and the second strip electrode 5 to adapt to the shape of the tissue 9 at the interface, improving the tightness of the contact between the first strip electrode 4 and the second strip electrode 5 and the tissue 9; reducing the gap between them and the tissue 9.

[0102] Reference Figure 1 and Figure 4 The bending curvature of the first strip electrode 4 is greater than that of the second strip electrode 5.

[0103] When the first strip electrode 4 and the second strip electrode 5 come into contact with the tissue 9, especially at a connection location such as the pulmonary vein ostium, the first strip electrode 4 will contact the smooth curved - surface connection of the tissue 9, and the second strip electrode 5 will contact the tissue 9 outside the connection. Therefore, to improve the integrity of the contact between the first strip electrode 4 and the second strip electrode 5 and the tissue 9 and reduce the gap between them and the tissue 9, the first strip electrode 4 and the second strip electrode 5 are arranged in a shape similar to the structure of the tissue 9 at the connection. That is, the first strip electrode 4 is similar to the curved - surface shape of the connection, while the second strip electrode 5 is similar to the shape of the annular tissue 9 outside the connection. The shape of the tissue 9 outside the connection is flatter. Therefore, in this application, the curvature of the first strip electrode 4 is set to be greater than that of the second strip electrode 5.

[0104] Reference Figure 1 and Figure 4 A connecting part 30 is arranged between the first strip electrode 4 and the second strip electrode 5, and the limiting component is connected to the connecting part 30.

[0105] On the one hand, the connecting part 30 is used to connect the first strip electrode 4 and the second strip electrode 5, thereby fixing the positions of the first strip electrode 4 and the second strip electrode 5, and the positions of the first strip electrode 4 and the second strip electrode 5 can be determined through the connecting part 30. At the same time, the first strip electrode 4 and the second strip electrode 5 can also control the distance through the connecting part 30. So that the first strip electrode 4 and the second strip electrode 5 can be controlled at an appropriate distance to ablate the tissue 9.

[0106] On the other hand, the connecting part 30 can also isolate the first strip electrode 4 and the second strip electrode 5. That is, insulate between the first strip electrode 4 and the second strip electrode 5, thereby reducing the possibility of short circuit between the first strip electrode 4 and the second strip electrode 5. At the same time, it can also prevent the first strip electrode 4 and the second strip electrode 5 from coming into contact and short-circuiting when they slide under resistance on the spoke 3. Further improving the safety of use of the first strip electrode 4 and the second strip electrode 5.

[0107] Reference Figure 1 and Figure 4 When the limiting component is arranged at the position of the connecting part 30 and the limiting component can control the shape of the spoke 3, since it is located between the first strip electrode 4 and the second strip electrode 5, it can also control the spoke 3 at the positions where the first strip electrode 4 and the second strip electrode 5 are located at the same time.

[0108] Reference Figure 1 and Figure 4 In this application, the first strip electrode 4 and the second strip electrode 5 are collectively referred to as ablation electrodes, and the spoke 3 is used to support the ablation. It is the basis for the shape and position of the ablation electrodes. Therefore, it is necessary to keep the shape of the spoke 3 basically consistent with the human tissue 9; so that the first strip electrode 4 and the second strip electrode 5 on the spoke 3 can be in close contact with the human tissue 9. And ablation is used to ablate the abutted tissue 9, which is the fundamental means to treat the tissue 9. Therefore, the position where the ablation electrode abuts against the tissue 9 and the ablation position of the ablation electrode on the tissue 9 play a crucial role in the treatment effect of the ablation surgery on the tissue 9; and the positioning accuracy of the ablation electrode also affects the ablation effect of the ablation electrode. In this application, the limiting component is arranged at the position of the connecting part 30, so that while controlling the shape of the spoke 3, the limiting component can also take into account adjusting the position and shape of the ablation electrode, which undoubtedly maximizes the function of the limiting component. Under the control of the limiting component, the spoke 3 and the ablation electrode can exert their maximum effects during the ablation surgery. Greatly improving the accuracy and success rate of the ablation surgery.

[0109] Reference Figure 1 and Figure 4, the distance from the first strip electrode 4 to the axis of the tube body 1 when unfolded is less than the distance from the second strip electrode 5 to the axis of the tube body 1 when unfolded.

[0110] Reference Figure 2 and Figure 3 , when the first strip electrode 4 is unfolded, it is mainly used to ablate the tissue 9 near the interior or near the connection port of the human tissue 9, while when the second strip electrode 5 is unfolded, it is used to ablate the tissue 9 located at the proximal end for the periphery of the connection port or the tissue 9 near the outside of the connection port. Obviously, the diameter of the tissue 9 ablated by the first strip electrode 4 is smaller at its location. Therefore, in this application, the diameter of the first strip electrode 4 in the unfolded state is set to be smaller than the diameter of the first strip electrode 4 in the unfolded state.

[0111] Among them, the distance from the first strip electrode 4 to the axis of the tube body 1 when in the unfolded state refers to the average distance from the first strip electrode 4 to the axis of the tube body 1, that is, the average of the distances from each part of the first strip electrode 4 to the axis of the tube body 1. Similarly, the distance from the second strip electrode 5 to the axis of the tube body 1 when in the unfolded state refers to the average distance from the second strip electrode 5 to the axis of the tube body 1.

[0112] The closest distance between the first strip electrode 4 and the second strip electrode 5 is 4 - 10 mm; preferably 6 - 8 mm.

[0113] Specifically, the closest distances between the first strip electrode 4 and the second strip electrode 5 are: 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm.

[0114] When the first strip electrode 4 is in the unfolded state, the closest distance from the first strip electrode 4 to the axis of the tube body 1 is 2 - 15 mm; preferably 3 - 8 mm.

[0115] Specifically, the distance from the first strip electrode 4 to the axis of the tube body 1 here respectively refers to the closest distance from the first strip electrode 4 to the axis of the tube body 1 and the farthest distance from the first strip electrode 4 to the axis of the tube body 1.

[0116] Specifically, the closest distances from the first strip electrode 4 to the axis of the tube body 1 are: 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, 10.5 mm, 11 mm, 11.5 mm, 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5 mm, 15 mm.

[0117] Further preferably, the maximum distance from the first strip-shaped electrode 4 to the axis of the tube body 1 is 2 to 15 mm; preferably 7 to 12 mm.

[0118] Specifically, the maximum distance from the first strip-shaped electrode 4 to the axis of the tube body 1 is: 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, 10.5 mm, 11 mm, 11.5 mm, 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5 mm, 15 mm.

[0119] When the second strip-shaped electrode 5 is in the unfolded state, the minimum distance range from the second electrode to the axis of the tube body 1 is 5 to 20 mm; preferably 7 to 12 mm.

[0120] Specifically, the minimum distance from the second strip-shaped electrode 5 to the axis of the tube body 1 is: 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, 10.5 mm, 11 mm, 11.5 mm, 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5 mm, 15 mm, 15.5 mm, 16 mm, 16.5 mm, 17 mm, 17.5 mm, 18 mm, 18.5 mm, 19 mm, 19.5 mm, 20 mm.

[0121] Further preferably, the maximum distance range from the second electrode to the axis of the tube body is 5 to 20 mm; preferably 10 to 15 mm.

[0122] Specifically, the distance from the second strip-shaped electrode 5 to the farthest axis of the tube body 1 is: 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, 10.5 mm, 11 mm, 11.5 mm, 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5 mm, 15 mm, 15.5 mm, 16 mm, 16.5 mm, 17 mm, 17.5 mm, 18 mm, 18.5 mm, 19 mm, 19.5 mm, 20 mm.

[0123] Reference Figure 1 and Figure 2 As shown in FIGS. 1 and 2, the limiting component includes a limiting film 31; a plurality of limiting films 31 are provided, and the limiting films 31 are all arranged between two adjacent spokes 3, and both ends of the limiting film 31 are respectively connected to the adjacent spokes 3.

[0124] ReferenceFigure 1 and Figure 2 In a specific embodiment, a limiting film 31 is used to connect two adjacent spokes 3. And the limiting film 31 is in a stretched state when the spokes 3 are in the deployed state, that is, when the spokes 3 are in the deployed state, two adjacent spokes 3 will stretch the limiting film 31. In other words, after the spokes 3 are deployed under normal conditions, the distance between two adjacent spokes 3 at the connection position with the limiting film 31 is greater than the length of the limiting film 31.

[0125] Therefore, referring to Figure 1 and Figure 2 after using the limiting film 31 to connect the adjacent spokes 3, the limiting film 31 will stretch the spokes 3 in the approaching direction, causing the spokes 3 to bend at the connection with the limiting film 31. And because the spokes 3 and the limiting film 31 are arranged in a ring shape and are connected end to end. Therefore, each spoke 3 will be simultaneously stretched by two limiting films 31 on opposite sides. At this time, when each spoke 3 is pulled by the two limiting films 31 and approaches each other, the spoke 3 will bend radially inward, making the connection with the limiting film 31 located at a position with a smaller diameter to reduce the distance between adjacent spokes 3.

[0126] Referring to Figure 2 and Figure 3 in the normal state, the spokes 3 in the deployed state are spherical or ellipsoidal; under the action of the limiting film 31, the spokes 3 present a shape sunken inward at the connection part 30. Furthermore, the spokes 3 are finally convex on the outside and concave on the inside in the deployed state. And the overall shape and size of the spokes 3 can also be adapted to the pulmonary vein orifices of different patients by controlling the length of the limiting film 31. Furthermore, the ablation electrodes located on the spokes 3 can be abutted against the tissue 9 of the patient to perform ablation surgery. Reduce the acting force of the spokes 3 on the tissue 9 and reduce the possibility of the spokes 3 causing harm to the tissue 9, and improve the success rate of the surgery.

[0127] Referring to Figure 1 and Figure 2 the limiting film 31 is a polymer film made of insulating material.

[0128] The limiting film 31 is used to connect the spokes 3. The limiting film 31 is connected to the connection part 30 of the spokes 3, and the connection part 30 is located between the first strip-shaped electrode 4 and the second strip-shaped electrode 5. Therefore, the insulating limiting film 31 can not only insulate between two adjacent spokes 3, but also insulate the first strip-shaped electrode 4 and the second strip-shaped electrode 5. Further improve the safety of the spokes 3 and the ablation electrodes during use. Contribute to improving the success rate of the surgery.

[0129] Referring to Figure 1And Figure 2 In addition, the limiting film 31 made of polymer material has higher elasticity, so that when the spoke 3 is deployed, it can provide sufficient elastic force to the spoke 3, causing the spoke 3 to bend. At the same time, the polymer film is also a relatively soft material, so that when the polymer film moves inside the human body, it will not scratch the tissue 9 like a metal sheet, further improving the safety of use of the limiting film 31. Moreover, the polymer film can ensure sufficient toughness in a state of relatively small thickness, and can make the size of the limiting film 31 smaller while ensuring the use state, so that the spoke 3 and the limiting film 31 can enter the human body more smoothly.

[0130] Reference Figure 1 And Figure 2 Also, the limiting film 31 can also be made of a soft but less elastic material. When the spoke 3 is in the deployed state, the limiting film 31 can firmly pull the spoke 3, thereby reducing the elastic deformation of the spoke 3 during use, so that the spoke 3 can more accurately reach the target position of the tissue 9 during use.

[0131] Reference Figure 6 As shown in, the limiting component includes a metal wire 32, and the metal wire 32 is arranged between two adjacent spokes 3; both ends of the metal wire 32 are respectively connected to the spoke 3.

[0132] Reference Figure 6 In another specific embodiment, the adjacent spokes 3 are connected by the metal wire 32. Similarly, the metal wire 32 is in a stretched state when the spoke 3 is deployed, so that when the spoke 3 is in the deployed state, the position of the spoke 3 at the connecting portion 30 is concave.

[0133] Reference Figure 6 Preferably, the metal wire 32 is a high-elastic metal wire.

[0134] The spokes 3 are connected by the metal wire 32 with relatively high elasticity. The metal wire 32 can provide sufficient elastic force to the deployed spokes 3, and at the same time, when the spokes 3 are in the contracted state, the metal wire 32 can be elastically deformed and stored between the spokes 3 along with the spokes 3. Thus, the total volume of the spokes 3 and the metal wire 32 in the contracted state is reduced.

[0135] Reference Figure 6 、 Figure 7 And Figure 8 One or more metal wires 32 are respectively arranged between every two adjacent spokes 3, and the metal wires 32 are arranged avoiding the first strip-shaped electrode 4 and the second strip-shaped electrode 5.

[0136] Among them Figure 8 In it is Figure 7The enlarged view in [reference] shows that there are two metal wires 32 on the spoke 3, which are two metal wires 32 respectively connected to the proximal and distal ends of the spoke 3.

[0137] In a specific embodiment, a plurality of metal wires 32 are provided between every two adjacent spokes 3. Specifically, the number of metal wires 32 between every two adjacent spokes 3 is: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

[0138] Reference Figure 6 , the plurality of metal wires 32 provided between the spokes 3 can also reinforce the metal wires 32. The distance between the two spokes 3 connected to the metal wire 32 is fixed.

[0139] Reference Figure 6 , the lengths of the plurality of metal wires 32 between the spokes 3 can be unequal. Specifically, the length of the metal wire 32 can be adapted according to the position where the metal wire 32 is connected to the spoke 3. And since the circumferentially arranged spokes 3 are in a spherical or ellipsoidal shape when unfolded, the distance between two adjacent spokes 3 is not equidistant, but the distance in the middle is far and the distances at both ends are close. Therefore, when using the metal wire 32 to fix the spoke 3, first preset the shape of the spoke 3 when unfolded. At this time, the length of the metal wire 32 after unfolding can be determined according to the distance between two adjacent spokes 3, and then the length of the metal wire 32 can be determined according to the elastic coefficient of the metal wire 32. Thus, the installation and fixation of the spoke 3 and the metal wire 32 are completed. At the same time, using a plurality of metal wires 32 to reinforce between the spokes 3 further reduces the possibility of deformation of the spokes 3 after unfolding, and further makes the spokes 3 more stable when abutting against the tissue 9.

[0140] In a specific embodiment, the number of metal wires 32 between every two adjacent spokes 3 is 1. That is Figure 6 there is only the metal wire 32 in the upper position in [reference]. At this time, both ends of the metal wire 32 are respectively fixed at the connecting part 30 of the spoke 3. At this time, the metal wire 32 can plastically deform the shape of the spoke 3. When the spoke 3 is in the unfolded state, the metal wire 32 is in a stretched state, and then the spoke 3 is stretched inward. Further, the spoke 3 will bend inward at the position of the connecting part 30, and then form a shape similar to that of the human tissue 9 at the connection port position.

[0141] Reference Figure 6 and Figure 7 , in another embodiment, the number of metal wires 32 between every two adjacent spokes 3 is 2.

[0142] Reference Figure 6, when the number of wires 32 arranged between two adjacent spokes 3 is two, the two wires 32 are respectively fixed to the connecting portion 30 and the proximal end of the second strip-shaped electrode 5. That is, one end of each of the wires 32 located between the two spokes 3 is respectively fixed to the connecting portion 30 of the two spokes 3, and the other wire 32 has both ends fixed to the proximal end positions of the two spokes 3, and both are located at the proximal end of the second strip-shaped electrode 5.

[0143] Reference Figure 6 , in the present application, since the wire 32 is located between every two spokes 3 and plays a supporting role for the spokes 3, when the wire 32 is connected to the spokes 3, the positions where the wire 32 is connected to the two spokes 3 are in a position where the two spokes 3 are opposite or in the same plane. Furthermore, when the wire 32 is connected to the spokes 3, it can keep the force balance among multiple spokes 3, and at the same time, when the spokes 3 and the wire 32 are converted between the contracted state and the expanded state, they can maintain balance.

[0144] Reference Figure 6 , after using two wires 32 to connect the spokes 3, the wire 32 has both a stretching and a fixing effect on both ends of the spokes 3. Therefore, when the spokes 3 are expanded from the contracted state to contact the tissue 9, the wire 32 located at the connecting portion 30 can maintain the shape of the spokes 3, while the wire 32 located at the proximal end can fix the spokes 3, reducing the occurrence of dislocation caused by deformation when the spokes 3 are subjected to the acting force of the tissue 9, and improving the use safety of the spokes 3.

[0145] Reference Figure 4 , the limiting component includes limiting flat wires 33. There are multiple limiting flat wires 33. One end of the limiting flat wire 33 is fixedly connected to the pull rod 11, and the other end of the limiting flat wire 33 is fixed to the spoke 3; the limiting flat wire 33 is connected to the connecting portion 30.

[0146] Reference Figure 4 , in one embodiment, the limiting flat wire 33 is used to limit the spoke 3. Both ends of the limiting flat wire 33 are respectively connected to the pull rod 11 and the spoke 3. Therefore, since the limiting flat wire 33 is located between the spoke 3 and the pull rod 11, when the spoke 3 contracts or expands under the action of the pull rod 11, the limiting flat wire 33 will also change accordingly and be hidden inside the spoke 3, thereby reducing the possibility of the flat wire contacting the human tissue 9 and reducing the possibility of the limiting flat wire 33 causing harm to the tissue 9. The use safety of the spoke 3 and the limiting flat wire 33 is improved.

[0147] Reference Figure 4 and Figure 5, when the spoke 3 is in the deployed state, the limiting flat wire 33 is in a stretched state. Therefore, the limiting flat wire 33 will pull the spoke 3 inward at the position of the connecting portion 30, and further cause the spoke 3 to be recessed inward at the position of the connecting portion 30, so that the distal portion of the spoke 3 forms a shape similar to the position of the connection port of the human tissue 9.

[0148] Reference Figure 4 and Figure 5 , both ends of the spoke 3 are fixedly connected to the tube body 1 and the head end 2 respectively. Therefore, when the head end 2 moves toward the proximal end under the action of the pull rod 11, the spoke 3 bends outward again. Furthermore, the spoke 3 will present a spherical or ellipsoidal shape with the pull rod 11 as the rotation center. At this time, the distance from each spoke 3 to the pull rod 11 is equal, and the distance from different positions on each spoke 3 to the pull rod 11 changes with the position. Therefore, after determining the shape of the preset spoke 3, the distance between the spoke 3 and the pull rod 11 will also change accordingly and then be determined. Therefore, the length of the limiting flat wire 33 can be determined through the distance between the spoke 3 and the pull rod 11. Then the limiting flat wire 33 is connected between the pull rod 11 and the spoke 3. Furthermore, after the spoke 3 changes from the contracted state to the deployed state, it can be shown in the preset shape under the tensile action of the limiting flat wire 33.

[0149] Reference Figure 4 and Figure 5 , the limiting component further includes an auxiliary flat wire 34 arranged between the spoke 3 and the pull rod 11. One end of the auxiliary flat wire 34 away from the spoke 3 is fixed to one end of the limiting flat wire 33 close to the pull rod 11; or one end of the limiting flat wire 33 away from the spoke 3 is fixed to the pull rod 11.

[0150] Reference Figure 4 and Figure 5 , the auxiliary flat wire 34 is used to assist in limiting the shape of the spoke 3, so that the spoke 3 can be limited to more or more suitable shapes. At the same time, the auxiliary flat wire 34 plastically deforms the shape of the spoke 3, so that the spoke 3 becomes stronger and can withstand greater resistance.

[0151] In a specific embodiment, reference Figure 4 and Figure 5 , the auxiliary flat wire 34 is fixed on the pull rod 11. When the pull rod 11 moves, it can not only drive the spoke 3 to deploy and close, but also drive the limiting flat wire 33 and the auxiliary flat wire 34 to move at the same time, so that the deformation of the limiting flat wire 33 and the auxiliary flat wire 34 can move with the contraction and expansion of the spoke 3.

[0152] Reference Figure 4 and Figure 5, the auxiliary flat wire 34 and the limiting flat wire 33 are respectively fixed on the pull rod 11, so that the limiting flat wire 33 and the auxiliary flat wire 34 can be independently combined with the movement of the pull rod 11. Therefore, when the limiting flat wire 33 breaks down due to a fault, the auxiliary flat wire 34 can still support the spoke 3. The applicability of the auxiliary flat wire 34 is improved.

[0153] In addition, the auxiliary flat wire 34 and the limiting flat wire 33 are independent of each other (not shown in the figure), and are respectively fixed between the pull rod 11 and the spoke 3, so that it is easier to process and install between the auxiliary flat wire 34 and the limiting flat wire 33. And because the auxiliary flat wire 34 and the limiting flat wire 33 are independent of each other and have little influence on each other, the design of the positions and lengths of the limiting flat wire 33 and the auxiliary flat wire 34 is relatively simple. Therefore, the design and manufacturing difficulty of the limiting flat wire 33 and the auxiliary flat wire 34 is greatly reduced, and the processing cost is also reduced.

[0154] Reference Figure 4 and Figure 5 , in another specific embodiment, the end of the auxiliary flat wire 34 is fixed on the limiting flat wire 33. The auxiliary flat wire 34 is connected to the pull rod 11 through the limiting flat wire 33. In this way, the connection positions between the auxiliary flat wire 34 and the pull rod 11 are reduced, so that there is only a connection point with the limiting flat wire 33 on the pull rod 11. When the pull rod 11 reciprocates on the tube body 1, it has a greater stroke. In addition, reducing the connection points between the limiting flat wire 33, the auxiliary flat wire 34 and the pull rod 11 further reduces the size of the pull rod 11, so that when the spoke 3 is in the retracted state, the overall volume of the spoke 3, the limiting flat wire 33, the auxiliary flat wire 34 and the pull rod 11 is reduced, and thus the spoke 3 can be more easily transported into the human body.

[0155] Reference Figure 4 and Figure 5 , in a specific embodiment, the limiting flat wire 33 and the auxiliary flat wire 34 are integrally formed, which improves the strength of the limiting flat wire 33 and the auxiliary flat wire 34 and reduces the possibility of damage when the limiting flat wire 33 and the auxiliary flat wire 34 limit the spoke 3.

[0156] Reference Figure 4 and Figure 5 , one end of the auxiliary flat wire 34 away from the pull rod 11 is fixed to the spoke 3, and the auxiliary flat wire 34 is fixed on the side of the spoke 3 close to the proximal end. Preferably, the auxiliary flat wire 34 is fixedly connected to the side of the proximal end of the second strip-shaped electrode 5.

[0157] The auxiliary flat wire 34 can reinforce the spoke 3. Therefore, when the auxiliary flat wire 34 is connected to the spoke 3, it avoids the position of the limiting guide wire at the distal end of the spoke 3 and is connected to the side of the proximal end of the spoke 3, and both the proximal end and the distal end of the spoke 3 are fixed, thereby realizing the overall fixation of the spoke 3.

[0158] Reference Figure 4 and Figure 5 Furthermore, since the spoke 3 is used to support the ablation, that is, it is supported by the first strip electrode 4 and the second strip electrode 5, so that the first strip electrode 4 and the second strip electrode 5 can come into contact with the tissue 9 for ablation. Therefore, in order to improve the stability of the ablation electrode, the auxiliary guide wire is connected to a position close to the second strip electrode 5, so that the auxiliary guide wire can provide a pulling force for the second strip electrode 5. When the front end of the second strip electrode 5 abuts against the tissue 9, the auxiliary guide wire can provide a pulling force to make the second strip electrode 5 abut more closely against the tissue 9. At the same time, due to the acting force of the auxiliary guide wire, the spoke 3 can also maintain the corresponding fixed shape, thereby improving the abutting condition between the second strip electrode 5 and the tissue 9.

[0159] In the deployed state, the closest distance between the ablation electrodes on two adjacent spokes 3 is 4 - 10 mm; preferably 6 - 8 mm.

[0160] Specifically, the closest distances between the ablation electrodes on two adjacent spokes 3 are: 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm.

[0161] Reference Figure 1 The distance between the ablation electrodes refers to the minimum distance between two ablation electrodes located on two adjacent spokes 3 at various positions. This distance is used to isolate the ablation electrodes and reduce the possibility of danger during the use of the ablation electrodes. To ensure the safe use of the ablation electrodes.

[0162] Reference Figure 1 A first magnetic sensor 6 is provided on the head end 2, and a second magnetic sensor 7 is provided at a position near the spoke 3 at the distal end of the tube body 1.

[0163] Reference Figure 1 When the first magnetic sensor 6 and the second magnetic sensor 7 are used in conjunction with a magnetic positioning system, they can accurately locate the positions of the first magnetic sensor 6 and the second magnetic sensor 7. Therefore, the user can locate the position of the head end 2 and the tube body 1. Furthermore, the head end 2 and the spoke 3 can be accurately delivered to the target position inside the human body. To improve the positioning accuracy of the head end 2 and the spoke 3.

[0164] Reference Figure 1, the first magnetic sensor 6 and the second magnetic sensor 7 are respectively located at both ends of the spoke 3. Therefore, when using the magnetic positioning system, the positions of both ends of the spoke 3 can be accurately known. Since the length of the spoke 3 is relatively long and the radial dimension of the spoke 3 is relatively large after it is unfolded. Using the magnetic positioning system and the first magnetic sensor 6 and the second magnetic sensor 7 can simultaneously determine the positions of both ends of the spoke 3. Furthermore, the spoke 3 in the unfolded state can be accurately positioned to the target position, and at the same time, the spoke 3 can be moved towards the target position in a suitable direction to achieve perfect abutment of the spoke 3 and the ablation electrode against the tissue 9. The positioning accuracy of the ablation electrode is improved.

[0165] In summary, the present application provides an ablation catheter for ablating the tissue 9. When the ablation catheter is used, the reciprocating movement of the head end 2 is realized through the pull rod 11, and at the same time, the unfolding and closing of the spoke 3 are driven. When the spoke 3 is unfolded, it is convex, so that the spoke 3 can abut against the tissue 9 at the pulmonary vein orifice, and then the ablation electrode is used to ablate the tissue 9.

[0166] When using the ablation catheter, first, the spoke 3 and the ablation electrode are delivered into the human body in cooperation with a sheath tube, and at the same time, positioning is performed through the first magnetic sensor 6 and the second magnetic sensor 7 to deliver the ablation electrode to the target position. Then, the pull rod 11 is pulled proximally to change the spoke 3 from the contracted state to the unfolded state. And under the action of the limiting component, the spoke 3 is unfolded into a convex structure, which is a structure similar to the tissue 9 at the pulmonary vein orifice. With the assistance of the magnetic positioning system, the position of the spoke 3 is adjusted to be able to contact the tissue 9. And the first strip electrode 4 and the second strip electrode 5 are abutted at the target position to contact the target tissue 9. The first strip electrode 4 and the second strip electrode 5 are used to perform ablation treatment on the tissue 9. After ablating the tissue 9, the spoke 3 is changed from the unfolded state to the contracted state through the pull rod 11 and withdrawn from the human body.

[0167] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. An ablation catheter, wherein, It includes a tube body and a head end. The head end is arranged at the distal end of the tube body. A pull rod is slidably connected inside the tube body, and the pull rod is fixed to the head end. The head end can move closer to or away from along the axis of the tube body under the action of the pull rod. A plurality of spokes are arranged between the tube body and the head end. When the head end moves closer to the tube body, the spokes will bend radially away from the tube body. A limiting component is arranged on the spokes to make the deformation of the spokes bend according to a set curvature.

2. The catheter according to claim 1, wherein the spokes include a first spoke and a second spoke; the first spoke is located at the distal position of the second spoke.

3. The catheter according to claim 2, wherein the length of the first spoke is less than the length of the second spoke.

4. The catheter according to claim 3, wherein the bending direction of the first spoke is opposite to the bending direction of the second spoke.

5. The catheter according to any one of claims 2 to 4, wherein the bending curvature of the first spoke is greater than the bending curvature of the second spoke.

6. The catheter according to claim 1, wherein a first strip-shaped electrode and a second strip-shaped electrode are arranged on the spokes. The first strip-shaped electrode is arranged at the distal end of the second strip-shaped electrode, and the first strip-shaped electrode is arranged at one end position of the spoke close to the head end.

7. The catheter according to claim 6, wherein the number of the spokes is 4 to 10.

8. The catheter according to claim 6, wherein a connecting part is arranged between the first strip-shaped electrode and the second strip-shaped electrode, and the limiting component is connected to the connecting part.

9. The catheter according to claim 6, wherein the bending directions of the first strip-shaped electrode and the second strip-shaped electrode are opposite.

10. The catheter according to claim 9, wherein the bending curvature of the first strip-shaped electrode is greater than the bending curvature of the second strip-shaped electrode.

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