Ablation catheter

Abstract

The ablation catheter is composed of an ablation component, an operation component and a connecting component, the ablation component is composed of an ablation unit, an inner tube and an outer tube, the inner tube penetrates through a tube cavity of the outer tube and extends out of the far end, the far end of the ablation unit is fixedly connected with the inner tube, and the near end of the ablation unit is fixedly connected with the far end of the outer tube. The inner tube is configured to move along the longitudinal axis of the outer tube to achieve conversion of the configuration of the ablation unit, the connecting component comprises an electric plug, the operating component comprises a handle and a telescopic deformation adjusting mechanism arranged on the handle, and the telescopic deformation adjusting mechanism is used for achieving conversion of the configuration of the ablation unit. The ablation unit comprises a plurality of petal branches, a plurality of ablation electrodes fixed to the petal branches and a plurality of wires, the ablation electrodes are connected with the electric plug through the wires, each petal branch is composed of an outer sleeve and an inner supporting piece arranged in the outer sleeve, and the hardness of the two ends of each inner supporting piece is larger than that of the middle section. The ablation unit has three configurations.

Description

Technical Field

[0001] The utility model relates to the technical field of pulsed electric field ablation, in particular to a pulsed electric field ablation catheter. Background Art

[0002] Pulsed electric field ablation is a new technology for treating atrial fibrillation. This technology uses high-voltage pulsed electric fields to act on myocardial tissue, causing the phospholipid bilayer of the cell membrane to move and rearrange under the action of the pulsed electric field, forming irreversible electroporation, and then causing cell apoptosis, so as to achieve the purpose of eliminating and preventing abnormal potential conduction. Compared with radiofrequency ablation and cryoablation, pulsed electric field ablation has the following characteristics: ablation has tissue selectivity and is based on a non-thermal ablation principle, so it is not easy to damage adjacent tissues, and the incidence of postoperative complications is very low, thus greatly improving the safety of the operation.

[0003] During pulsed electric field ablation, for adjustable ablation catheters in a basket shape and a flower shape, the following problems usually exist: Since the ablation unit is a hollow structure, when the ablation unit of the catheter reaches the lesion tissue, if the regional space is too small or irregular, the petal branches of the catheter may be squeezed and deformed, resulting in an electric arc generated during ablation between petals that are relatively close and possibly forming a thrombus, and insufficient ablation between petals that are relatively far away, forming leakage points, thus affecting the safety and effectiveness of the operation. There are mainly two factors causing this problem: one is that if the basket-shaped and flower-shaped ablation catheters are to be able to expand and contract normally, each branch cannot be too hard, otherwise the branches are likely to break when the catheter is adjusted from the basket shape to the flower shape; the other is that if the catheter is to maintain a good shape in the basket shape without being squeezed and deformed by tissues, each branch needs to have a certain hardness. Therefore, on the premise of enabling the basket-shaped and flower-shaped ablation catheters to expand and contract normally, it is of great clinical significance to improve the anti-squeezing and deformation ability of the petal branches.

[0004] Chinese Patent CN 116158839 A discloses a system, device, and method for delivering pulsed electric field ablation energy to endocardial tissue. The device includes a set of splines coupled to a catheter for medical ablation therapy. Each spline in the set of splines may include a set of electrodes formed on the spline. The set of splines may be configured for translation to transition between a first configuration and a second configuration. Each spline in the set of splines in the second configuration may be petal-shaped. Although this device can be converted into a petal shape, the anti-squeezing and deformation ability of the splines is poor, thus affecting the safety and effectiveness of the operation.

[0005] Chinese patent CN 114305660 A discloses a pulse ablation catheter and a pulse ablation device. The pulse ablation catheter includes an ablation component and a support frame. The ablation component includes a first connection part, a second connection part and an ablation element, and the ablation element is arranged at the first connection part and / or the second connection part. The support frame includes a support component, a first connection part and a second connection part connected to each other, the first connection part connects the first connection part, and the second connection part connects the second connection part. The support component is used to limit the radial expansion and contraction between the first connection part and the second connection part, so as to limit the movement of the ablation element on the first connection part and / or the second connection part relative to the support component. The support component limits the radial expansion and contraction of the first connection part through the first connection part, and limits the radial expansion and contraction of the second connection part through the second connection part, thereby limiting the radial shaking of the ablation element relative to the support component along the pulse ablation catheter, avoiding the generation of arcs or electric sparks, and causing breakdown damage to the target tissue. The supporting skeleton of the invention is a hexagonal structure, which only solves the ability of the catheter to maintain its shape in a basket shape, but creates the following new problems: 1) The catheter cannot be smoothly unfolded from a basket shape to a flower shape, and ablation of the pulmonary vein vestibule cannot be achieved in actual surgery, thus affecting the actual surgical effect; 2) Based on the introduction of the hexagonal supporting skeleton structure, the production and processing difficulty of the catheter is greatly improved, which may affect the safety of the operation and the qualified rate of the finished catheter to a certain extent; 3) Due to the introduction of the hexagonal supporting skeleton structure, the size of the catheter body may increase to a certain extent, which will simultaneously increase the size of the guide sheath that matches the catheter, thereby reducing the passability of the catheter before reaching the lesion area, and also reducing the operability of the catheter after reaching the lesion area. Summary of the invention

[0006] In view of the above analysis, the utility model aims to provide an ablation catheter to solve the problems of poor anti-extrusion deformation capability of the petal branches of the ablation catheter and complex structure of the catheter ablation component.

[0007] The present utility model provides an ablation catheter, which is composed of an ablation component, an operation component and a connection component. Among them, the ablation component is composed of an ablation unit, an inner tube and an outer tube. The inner tube passes through the lumen of the outer tube and extends outside the distal end of the lumen. The distal end of the ablation unit is fixedly connected to the inner tube, and the proximal end of the ablation unit is fixedly connected to the distal end of the outer tube. The inner tube is configured to move along the longitudinal axis of the outer tube to achieve the conversion of the configuration of the ablation unit. The connection component includes an electrical plug, and the operation component includes a handle and a telescopic deformation adjustment mechanism arranged on the handle. The telescopic deformation adjustment mechanism is used to achieve the conversion of the configuration of the ablation unit. The ablation unit includes a plurality of petal branches, a plurality of ablation electrodes fixed on the petal branches and a plurality of wires. The ablation electrodes are connected to the electrical plug through the wires. The petal branch is composed of an outer sleeve and an inner support member arranged inside the outer sleeve. The proximal ends of the outer sleeve and the inner support member are fixedly connected to the distal end of the outer tube through a proximal fixing member of the ablation unit. The distal ends of the outer sleeve and the inner support member are fixedly connected to the inner tube through a distal fixing member of the ablation unit. The hardness of both ends of the inner support member is greater than that of the middle section. The ablation unit has three configurations. The first configuration is a contracted state in which the petal branches of the ablation unit are close to the longitudinal axis of the inner tube. The second configuration is a basket shape formed by the petal branches of the ablation unit expanding radially outward along the inner tube. The third configuration is a flower shape formed by the proximal and distal ends of the petal branches of the ablation unit approaching each other.

[0008] Further, the hardness of the inner support member gradually decreases from both ends to the middle.

[0009] Furthermore, the inner support member is made of a shape memory alloy with variable stiffness.

[0010] Furthermore, the inner support member is made of a shape memory alloy, and the outer diameter of the inner support member is variable.

[0011] Further, the proximal fixing member of the ablation unit and the distal fixing member of the ablation unit are of a hollow structure. A plurality of openings are provided on the tube walls of the proximal fixing member of the ablation unit and the distal fixing member of the ablation unit. Both ends of the inner support member are respectively inserted into the openings provided in the proximal fixing member of the ablation unit and the distal fixing member of the ablation unit. The hole spacing between two adjacent openings is the same, and the number of the openings matches the number of the petal branches.

[0012] Further, the proximal fixing member and the distal fixing member of the ablation unit are composed of an outer fixing member and an inner locking member. Both the outer fixing member and the inner locking member are of a hollow structure. The outer fixing member is sleeved outside the inner locking member. The hollow cavity of the inner locking member is an inner tube channel. The inner wall of the outer fixing member is provided with a plurality of inner bosses and inner grooves. The outer wall of the inner locking member is provided with a plurality of outer bosses and outer grooves. The outer bosses are aligned with the inner bosses, and the outer grooves are aligned with the inner grooves. Both ends of the internal support member are respectively received in the spaces defined by the inner grooves and the outer grooves. The outer fixing member and the inner locking member are in mechanical interference fit to fix the internal support member. The number of the inner bosses, inner grooves, the number of the outer bosses and outer grooves match the number of the petal branches.

[0013] Furthermore, the sum of the heights of the outer boss and the inner boss is equal to the height of the distal fixing member or the proximal fixing member of the ablation unit.

[0014] Further, after pre-shaping, a small angular offset in opposite directions is provided at the distal end and the proximal end of the internal support member, and the middle part of the internal support member has an arc-shaped structure. In a preferred embodiment, the distal end of the internal support member is offset 5 - 60° to the left relative to the axis of the inner tube, and the proximal end of the internal support member is offset 5 - 60° to the right relative to the axis of the inner tube.

[0015] Furthermore, the offset angle of the distal end of the internal support member is equal to the offset angle of the proximal end of the internal support member.

[0016] Furthermore, the longitudinal projections of the distal end and the proximal end of the internal support member do not coincide. Preferably, the longitudinal projections of the distal end and the proximal end of the internal support member have a certain horizontal distance.

[0017] Further, a bending adjustment mechanism for adjusting the bending degree of the ablation component is provided on the handle. The bending adjustment mechanism is fixedly connected to the proximal end of a bending adjustment wire. The distal end of the bending adjustment wire is fixedly connected to the distal end of the outer tube. By pushing the movement of the bending adjustment mechanism, the bending adjustment wire arranged inside the outer tube can be driven to move, so that the outer tube bends to one side under the action of the pulling force of the bending adjustment wire, thereby driving the ablation component to bend to the same side.

[0018] Compared with the prior art, the present utility model can at least achieve one of the following beneficial effects:

[0019] 1. The petal branches of the ablation unit of the present utility model are composed of an outer sleeve and an inner support member disposed within the outer sleeve. An inner support member made of a shape memory alloy material is disposed inside the outer sleeve of the petal branch, strengthening the hardness of the petal branch, enhancing the anti-extrusion deformation ability of the petal branch, enabling the transformation of three configurations, and having good clinical effects.

[0020] 2. The hardness of the inner support member of the present utility model gradually decreases from both ends to the middle. The shape memory alloy material used to make the inner support member has variable hardness characteristics, or the outer diameter of the inner support member made of shape memory alloy is variable, specifically manifested as hard at both ends and soft in the middle, with the hardness gradually decreasing from both ends to the middle. When the catheter is in a basket shape, the harder parts at both ends of the inner support member make the petal branches at both ends harder, which can better resist external forces to maintain a better catheter shape. Since the middle part of the inner support member is softer, the catheter can be more easily deployed from the basket shape to the flower shape. On the premise of realizing the normal conversion of the ablation catheter from the basket shape configuration to the flower shape configuration, the present utility model synchronously improves the anti-extrusion deformation ability of the ablation unit.

[0021] 3. After the inner support member of the present utility model is pre-shaped, there will be a small angular offset in opposite directions at the distal end and the proximal end of the inner support member. In addition, there is a small arc outward in the middle part of the inner support member. When the catheter unfolds from the basket shape to the flower shape, the inner support member is subjected to pressure from above and below, and its distal end and proximal end will deform in the direction of their respective offset angles. Coupled with the initial arc in the middle part, it can more easily achieve the unfolding of the flower shape and effectively reduce the risk of breakage of the catheter petal branches.

[0022] 4. At both ends of each petal branch of the ablation unit of the present utility model, there are respectively a proximal fixing member and a distal fixing member of the ablation unit to fix the inner support member of the petal branch, preventing the inner support member from shifting. And the same setting of the hole spacing of the openings on the proximal fixing member and the distal fixing member of the ablation unit maintains a uniform spacing between the petal branches, thereby further improving the shape maintenance ability of the ablation catheter.

[0023] 5. Each petal branch of the ablation unit of the present utility model is an ordinary regular part without adding other special-shaped structures, thereby reducing the production and processing difficulty of the ablation catheter. Moreover, the design of the distal fixing member and the proximal fixing member of the ablation unit also improves the consistency of the ablation catheter during production and the stability of the catheter during use.

[0024] In the present utility model, the above technical solutions can also be combined with each other to achieve more preferred combined solutions. Other features and advantages of the present utility model will be described in the subsequent description, and some advantages can be made obvious from the description or understood by implementing the present utility model. The objectives and other advantages of the present utility model can be achieved and obtained from the content specifically pointed out in the description and the drawings. Description of the Drawings

[0025] The drawings are only for the purpose of showing specific embodiments and are not considered as a limitation to the present utility model. Throughout the drawings, the same reference signs denote the same components.

[0026] Figure 1A Schematic structural diagram of an ablation catheter with a basket-shaped ablation unit in the deployed state.

[0027] Figure 1B Schematic structural diagram of a structure with a flower-shaped ablation unit in the deployed state.

[0028] Figure 1C Partial enlarged schematic diagram of the petal branches of the ablation unit.

[0029] Figures 1D - 1G Schematic diagrams of various embodiments of the electrode arrangement on the ablation unit.

[0030] Figure 2A Schematic structural diagram of one embodiment of the ablation unit.

[0031] Figure 2B Schematic structural diagram of another embodiment of the ablation unit.

[0032] Figure 3A Schematic structural diagram of one structure of the internal support member.

[0033] Figure 3B Schematic structural diagram of another structure of the internal support member.

[0034] Figure 3C Schematic structural diagram of the internal support member after pre-forming treatment.

[0035] Figure 4A Schematic structural diagram of one structure of the distal fixing member of the catheter ablation unit and the proximal fixing member of the catheter ablation unit.

[0036] Figure 4B Schematic structural diagram of another structure of the distal fixing member of the catheter ablation unit and the proximal fixing member of the catheter ablation unit.

[0037] Figure 4C Top view of the outer fixing member and the inner locking member in the proximal fixing member or the distal fixing member of the catheter ablation unit after being fixed in cooperation.

[0038] Figure 5A The top view after the ablation unit is unfolded into a flower shape.

[0039] Figure 5B The side view after the ablation unit is unfolded into a flower shape.

[0040] Reference numerals:

[0041] 1. Ablation component; 2. Operating component; 3. Connecting component; 11. Ablation unit; 12. Inner tube; 13. Outer tube; 21. Handle; 31. Electrical plug; 32. Peripheral sheath; 33. Luer connector; 101. First petal branch; 102. Second petal branch; 102’. Offset second petal branch; 103. Third petal branch; 105. Vertical ablation area; 106. Parallel ablation area; 107. Acute-angle ablation area; 108. Obtuse-angle ablation area; 111. Petal branch; 112. Ablation electrode; 113. Wire; 114. Distal end of the ablation unit; 115. Proximal end of the ablation unit; 211. Telescopic deformation adjustment mechanism; 212. Bending adjustment mechanism; 1021. Initial position; 1111. Outer sleeve; 1112. Inner support; 1113. Proximal fixation member of the ablation unit; 1114. Distal fixation member of the ablation unit; 1115. Distal offset angle; 1116. Proximal offset angle; 1117. Horizontal spacing; 11121. Both end portions of the inner support; 11122. Middle section of the inner support; 11141. Opening in the inner support; 11142. Outer fixing member; 11143. Inner locking member; 11144. Inner boss; 11145. Inner groove; 11146. Outer boss; 11147. Outer groove. Detailed implementation manners

[0042] To make the objectives, technical solutions and advantages of the present application clearer and more understandable, the following examples are given with reference to the accompanying drawings to further elaborate on the present application in detail.

[0043] As used in the present utility model, the "proximal end" refers to the end close to the surgical operator, and the "distal end" refers to the end far from the surgical operator.

[0044] Such as Figure 1AAs shown, an ablation catheter is composed of an ablation component 1, an operating component 2, and a connecting component 3. Among them, the ablation component 1 is composed of an ablation unit 11, an inner tube 12, and an outer tube 13. The inner tube 12 passes through the lumen of the outer tube 13 and extends outside the distal end of the lumen. The distal end of the ablation unit 11 is fixedly connected to the inner tube 12, and the proximal end of the ablation unit 11 is fixedly connected to the distal end of the outer tube 13. The inner tube 12 is configured to move along the longitudinal axis of the outer tube 13 to achieve the conversion of the configuration of the ablation unit 11. The connecting component 3 is composed of an electrical plug 31, a peripheral sheath 32, and a Luer connector 33. One end of the connecting component 3 is connected to the ablation host through the electrical plug 31, and the other end of the connecting component 3 is fixedly connected to the operating component 2. The operating component 2 includes a handle 21 and a telescopic deformation adjustment mechanism 211 provided on the handle 21. The telescopic deformation adjustment mechanism 211 is used to adjust the configuration conversion of the ablation unit 11, such as adjusting the contraction and expansion of the ablation unit 11. The ablation unit 11 includes a plurality of petal branches 111, a plurality of ablation electrodes 112 fixed on the petal branches 111, and a plurality of wires 113. The ablation electrodes 112 are connected to the electrical plug 31 through the wires 113. The electrical plug 31 is the electrical connection part between the ablation catheter and the ablation host, and is used to conduct the high-voltage pulse output of the ablation host to the ablation electrodes 112 of the ablation unit 11, and apply the high-voltage pulse to the pre-ablation tissue in the heart. The inner tube 12 passes through the handle 21 and is connected to the Luer connector 33. The Luer connector 33 is used to connect some external devices, so as to realize functions such as the ablation catheter can deliver heparinized saline, deliver contrast agent, and drain excess blood. The peripheral sheath 32 is provided to protect the wires 113 extending from the handle 21.

[0045] The ablation unit 11 has three configurations. The first configuration is the contracted state in which the petal branches 111 of the ablation unit 11 are close to the longitudinal axis of the inner tube 12; as Figure 1A shown, the second configuration is the basket-like shape formed by the petal branches 111 of the ablation unit 11 expanding radially outward along the inner tube 12; as Figure 1B shown, the third configuration is the flower-like shape formed by the proximal and distal ends of the petal branches 111 of the ablation unit 11 approaching each other.

[0046] As Figure 1AAs shown, a bending adjustment mechanism 212 is further provided on the handle 21. The bending adjustment mechanism 212 is used to adjust the bending degree of the ablation component 1, so that the ablation component 1 can at least achieve two degrees of freedom of adjustment, and the bending angle can be at least 60 degrees in each degree of freedom. The bending adjustment mechanism 212 is fixedly connected to the proximal end of the bending wire, and the distal end of the bending wire is fixedly connected to the distal end of the outer tube 13. By pushing the movement of the bending adjustment mechanism 212, the bending wire arranged inside the outer tube 13 can be driven to move, so that the outer tube 13 bends to one side under the action of the pulling force of the bending wire, thereby driving the ablation component 1 to bend to the same side. During the operation, when the ablation unit 11 has not reached the pre-ablation tissue area, the ablation unit 11 is in a contracted state, and the outer diameter of the ablation unit 11 is equivalent to the outer diameter of the outer tube 13 of the ablation component 1 (refer to Figure 1A d therein); when the ablation unit 11 has reached the pre-ablation tissue area, the ablation unit 11 is adjusted to an unfolded state through the telescopic deformation adjustment mechanism 211. The unfolded state can be a basket shape (refer to Figure 1A ), or it can be a flower shape (refer to Figure 1B ). At this time, the ablation electrode 112 is brought into contact with the pre-ablation tissue, and then a high-voltage pulse output is applied to achieve tissue ablation. In one embodiment, the ablation unit 11 includes at least 4 petal branches 111, and at least 2 ablation electrodes 112 are fixed on each petal branch 111.

[0047] As Figure 1C shown, the petal branch 111 is composed of an outer sleeve 1111 and an inner support 1112. Four ablation electrodes 112 are fixed on the outer sleeve 1111, and the fixing methods include but are not limited to mechanical forging or glue adhesion, etc. The materials of the ablation electrodes include but are not limited to gold, copper, aluminum, stainless steel, and platinum-iridium alloy, etc. Each ablation electrode corresponds to a wire 113 for electrical connection, and the electrical connection methods include but are not limited to soldering, laser welding, and other conductive metal welding. The inside of each wire is a conductive material, including but not limited to gold, copper, aluminum, stainless steel, and platinum-iridium alloy, etc., and the surface of the wire is an electrically insulating material with a certain thickness, including but not limited to insulating paint or insulating polymer materials, etc. The voltage withstand between every two wires can be at least more than 1000V, and each wire and the corresponding electrode can be independently addressed and configured as an anode or a cathode.

[0048] As Figure 1D shown, for the same petal branch, all the ablation electrodes 112 above can be configured with the same polarity (anode or cathode), and the polarities of the ablation electrodes on adjacent two petal branches are opposite, so as to form a vertical ablation area 105 perpendicular to the direction of the petal branch 111.

[0049] As Figure 1EAs shown, for the same petal branch 111, all the ablation electrodes 112 thereon can be configured with pairwise different polarities, and the polarities of the corresponding ablation electrodes on two adjacent petal branches 111 are the same, so as to form a parallel ablation region 106 parallel to the direction of the petal branch 111.

[0050] As Figure 1F shown, for the same petal branch 111, all the ablation electrodes 112 thereon can be configured with pairwise different polarities, and the polarities of the corresponding electrodes on two adjacent petal branches 111 are opposite, so as to simultaneously form a vertical ablation region 105 perpendicular to the direction of the petal branch 111 and a parallel ablation region 106 parallel to the direction of the petal branch 111.

[0051] As Figure 1G shown, for the same petal branch 111, all the ablation electrodes 112 thereon can be configured with pairwise different polarities, the polarities of the corresponding ablation electrodes on two adjacent petal branches 111 are opposite, and the corresponding electrodes on two adjacent petal branches 111 are mutually offset. A parallel ablation region 106 parallel to the direction of the petal branch 111 is formed on the same petal branch 111, and an ablation region 107 forming an acute angle with the petal branch and an ablation region 108 forming an obtuse angle are formed between two adjacent petal branches.

[0052] During the ablation process, each ablation electrode 112 can be configured to include but not limited to Figure 1D , Figure 1E , Figure 1F or Figure 1G shown positions and polarities, or can be first configured to a certain electrode position and polarity in the figure, and then configured to another electrode position and polarity after ablation. At least one pair of electrodes with opposite polarities can be configured to discharge during ablation, multiple pairs of electrodes with opposite polarities can also be configured to discharge simultaneously, or all electrodes can discharge simultaneously.

[0053] As Figure 2AAs shown, the ablation unit 11 is composed of a plurality of (at least 4) petal branches 111. Each petal branch 111 consists of an outer sleeve 1111 and an inner support 1112 disposed within the outer sleeve 1111. The proximal ends of the outer sleeve 1111 and the inner support 1112 are fixedly connected to the distal end of the outer tube 13 through an ablation unit proximal fixing member 1113. The distal ends of the outer sleeve 1111 and the inner support 1112 are fixedly connected to the inner tube 12 through an ablation unit distal fixing member 1114. The hardness of the two end portions 11121 of the inner support is greater than that of the middle section 11122 of the inner support. A plurality of (at least 2) ablation electrodes 112 are fixedly mounted on the surface of each petal branch 111. The outer sleeve 1111 is a hollow structure and is made of a biocompatible elastic material, which includes but is not limited to materials such as high-performance polyurethane or polytetrafluoroethylene. The inner support 1112 is made of a shape memory alloy material, which includes but is not limited to materials such as nitinol or stainless steel. The cross-sectional shape of the inner support includes but is not limited to rectangular, square, oval, or cylindrical shapes. The ablation electrode 112 is made of a conductive material, which includes but is not limited to materials such as gold, copper, aluminum, stainless steel, or platinum-iridium alloy. The distal ends of the outer sleeves 1111 of all petal branches 111 converge at the distal end 114 of the ablation unit 11, and the distal ends of the inner supports 1112 converge at the ablation unit distal fixing member 1114. The proximal ends of the outer sleeves 1111 of all petal branches 111 converge at the proximal end 115 of the ablation unit 11, and the proximal ends of the inner supports 1112 converge at the ablation unit proximal fixing member 1113. The distal end 114 of the ablation unit 11, the ablation unit distal fixing member 1114, and the inner tube 12 are all fixed at the distal end of the ablation catheter. The proximal end 115 of the ablation unit 11, the ablation unit proximal fixing member 1113, and the outer tube 13 are all fixed at the distal end of the outer tube 13.

[0054] During the operation, by pushing the inner tube 12 to apply an external force to the petal branches 111, the ablation unit 11 can be respectively in two unfolded forms: a basket shape and a flower shape. Specifically, if the ablation unit 11 is in a contracted state at this time, since the distal end 114 of the ablation unit 11, the ablation unit distal fixing member 1114, and the inner tube 12 are all fixed at the distal end of the ablation catheter, and the proximal end 115 of the ablation unit 11, the ablation unit proximal fixing member 1113, and the outer tube 13 are all fixed at the distal end of the outer tube 13. When the inner tube 12 is pulled in the proximal direction of the ablation catheter, the upper end of the petal branch 111 receives a downward pressure, and the lower end of the petal branch 111 receives an upward pressure, causing each petal branch 111 to bend towards the middle, thus forming as Figure 1AThe shown basket shape. Further, if the inner tube 12 is pulled further downwards, since the outer sleeve 1111 is an elastic material and the inner support member 1112 is a shape memory alloy material, when the distal end 114 of the ablation unit 11 touches the proximal end 115 of the ablation unit 11, at this time each petal branch 111 will form an elliptical shape, so that the ablation unit 11 forms as Figure 1B the shown flower shape. If the inner tube 12 is pushed towards the distal end direction of the ablation catheter, the ablation unit 11 will slowly recover from the flower shape to the basket shape and finally be in a contracted state.

[0055] As Figure 2B shown, taking three petal branches 111 in the ablation unit 11 as an example, for the sake of convenience of description, these three petal branches are respectively named the first petal branch 101, the second petal branch 102 and the fourth petal branch 103. The initial position of the second petal branch 102 is at 1021. At this time, the distance between the petal branch 101 and the initial position 1021 is equal to the distance between the petal branch 103 and the initial position 1021. For the basket-shaped and flower-shaped adjustable ablation catheter (refer to Figure 1A and Figure 1B ), since the ablation unit 11 at the distal end of the catheter is a hollow structure, when the catheter reaches the lesion tissue, if the regional space is too small or irregular, it may cause the second petal branch 102 of the catheter to be deformed by the lateral extrusion force 220 to the left and shift to the offset second petal branch 102'. As a result, the distance between the first petal branch 101 and the offset second petal branch 102' is relatively close, while the distance between the third petal branch 103 and the offset second petal branch 102' is relatively far, resulting in an electric arc being generated between the relatively close petal branches during ablation and possibly forming a thrombus, and insufficient ablation between the relatively far petal branches resulting in leakage points, thus affecting the safety and effectiveness of the operation. Therefore, the present utility model proposes to design the inner support member 1112 such that the hardness of its two end portions is greater than that of the middle section. Different schemes can be adopted to make the hardness of the two end portions of the inner support member 1112 greater than that of the middle section. One of the schemes is to use a shape memory alloy material with variable hardness characteristics to make the inner support member 1112, so that on the premise of realizing the normal expansion and contraction of the basket shape or the flower shape of the ablation unit 11, the anti-extrusion deformation ability of the ablation unit 11 is improved. Another scheme can achieve the change of its hardness by changing the outer diameter of the inner support member 1112. In one embodiment, the hardness of the inner support member 1112 gradually decreases from both ends to the middle. As Figure 3AAs shown, the hardness of the internal support member 1112 is gradually changed, decreasing gradually from both ends to the middle. Specifically, the two end portions 11121 of the internal support member are hard, and the middle section 11122 of the internal support member is soft. The internal support member 1112 is made of a shape memory alloy material with variable stiffness characteristics. Specifically, for the two end portions 11121 of the internal support member, a shape memory alloy material with relatively high hardness itself can be used, and for the middle section 11122 of the internal support member, a shape memory alloy material with relatively low hardness itself can be used. The two are fixed at the junction by means including but not limited to laser welding or metal welding. In addition, the two end portions 11121 of the internal support member and the middle section 11122 of the internal support member can use the same shape memory alloy material. During the pre-forming process, a gradually changing forming temperature is used from the two end portions 11121 of the internal support member to the middle section 11122 of the internal support member, so as to achieve the variable stiffness characteristic of the same shape memory alloy material. When the ablation unit 11 is in a basket shape, if the space of the lesion tissue area is too small or irregular, causing the catheter petal branches 111 to be subjected to lateral extrusion force, at this time, due to the relatively hard two end portions 11121 of the internal support member, the lateral extrusion force can be well resisted, so as to maintain a better unfolded shape of the ablation unit 11 and prevent the situation that the distance between some of the petal branches 111 is relatively close and that between some other petal branches 111 is relatively far, thereby increasing the safety and effectiveness of catheter ablation to a certain extent. In addition, due to the relatively soft middle section 11122 of the internal support member, the ablation unit 11 can be easily unfolded from the basket shape to the flower shape, thus avoiding the risk of the petal branches 111 being broken due to the excessive hardness of the internal support member 1112.

[0056] In another embodiment, as Figure 3BAs shown, the hardness of the internal support member 1112 gradually changes and decreases gradually from both ends towards the middle. The internal support member 1112 is made of a shape memory alloy material with a variable outer diameter, specifically, the outer diameters of the two end portions 11121 of the internal support member are large, and the outer diameter of the middle section 11122 of the internal support member is small. The outer diameter of the internal support member 1112 gradually decreases from both ends towards the middle. Specifically, the internal support member 1112 can be formed by connecting shape memory alloy materials with different outer diameters, and fixed at the joints by means including but not limited to laser welding or metal welding. In addition, for the internal support member 1112 made of a single shape memory alloy material with a relatively large outer diameter, during the pre-forming process, surface treatment is performed on the middle section 11122 of the internal support member from the two end portions 11121 of the internal support member by means including but not limited to metal grinding, laser cutting, biochemical corrosion, electrochemical corrosion, etc., so as to achieve the function of variable outer diameter of a single shape memory alloy material and realize the characteristic of variable stiffness. When the ablation unit 11 is in a basket shape, if the space of the lesion tissue area is too small or irregular, causing the petal branches 111 to be subjected to lateral extrusion force, at this time, due to the relatively large outer diameters of the two end portions 11121 of the internal support member, their hardness is relatively large, so they can well resist the lateral extrusion force to maintain a better unfolded shape of the ablation unit 11 and prevent the situation where the distances between some of the catheter petal branches 111 are relatively close while some are relatively far, thereby increasing the safety and effectiveness of catheter ablation to a certain extent. In addition, since the outer diameter of the middle section 11122 of the internal support member is small, its hardness is small, so the ablation unit 11 can easily unfold from the basket shape to the flower shape, thus avoiding the risk of petal branch breakage caused by the excessive hardness of the internal support member.

[0057] Figure 3CIt is the structure of the inner support member 1112 after pre-shaping. After pre-shaping, a small-angle offset with opposite directions is provided at the distal end and the proximal end of the inner support member 1112, and the middle part 11122 of the inner support member 111 has an arc-shaped structure. Specifically, before the inner support member 1112 is fixed to the ablation unit distal end fixing member 1114 and the ablation unit proximal end fixing member 1113, a pre-shaping operation is performed on the inner support member 1112, and this operation includes but is not limited to high-temperature heat treatment, quenching, tempering, normalizing or annealing, etc. During the pre-shaping process, the distal end of the inner support member 1112 has a distal offset angle 1115 to the left relative to the axis of the inner tube, and the offset angle is 5 - 60°, and the proximal end of the inner support member 1112 has a proximal offset angle 1116 to the right relative to the axis of the inner tube, and the offset angle is 5 - 60°, and the middle section 11122 of the inner support member will generate a curvature outward. Further, the distal offset angle 1115 of the inner support member 1112 is equal to the proximal offset angle 1116 of the inner support member. This offset angle has no obvious influence on the appearance and static physical properties of the inner support member 1112, but can make the catheter easier to expand from a basket shape to a flower shape. Specifically, as Figure 3C shown, if the ablation unit 11 is in a basket shape at this time, and if the inner tube 12 is pulled further in the proximal direction, the distal end of the inner support member 1112 is subjected to a downward pressure, and the proximal end of the inner support member 1112 is subjected to an upward pressure. If the inner support member 1112 is not subjected to any treatment and is similar to a straight rod, when pressures are applied to both the upper and lower ends simultaneously, the inner support member 1112 will bend towards the middle and thus is not easily expanded into a flower shape, and if the pressure is too large, it may cause the inner support member 1112 to be broken. The pre-shaping operation performed on the inner support member 1112 in the present utility model makes the distal end of the inner support member 1112 have a distal offset angle 1115 to the left, and the proximal end of the inner support member 1112 has a proximal offset angle 1116 to the right. When pressures are applied to both ends of the inner support member 1112 simultaneously, the distal end will deform along the left offset angle, and the proximal end will deform along the right offset angle. Combining with the initial curvature retained in the middle section 11122 of the inner support member, it can thus more easily achieve Figure 1B the expansion of the flower shape shown, and effectively reduce the risk of breakage of the catheter petal branches.

[0058] Figure 4AIt is a schematic structural diagram of the distal fixing member 1114 of the ablation unit. The distal fixing member 1114 of the ablation unit is a hollow structure, which is used to pass through the inner tube 12 and fix the three with the distal end 114 of the ablation unit 11. Among them, the materials of the distal fixing member 1114 of the ablation unit include but are not limited to various metal materials and polymer materials, and the appearance includes but is not limited to shapes such as cylinders, cuboids, cubes, etc. There are no less than 4 internal support member openings 11141 inside the tube wall of the distal fixing member 1114 of the ablation unit. The specific quantity matches the quantity of the petal branches 111. The shapes of the internal support member openings 11141 include but are not limited to shapes such as cylinders, cuboids, cubes, etc. The structure of the proximal fixing member 1113 of the ablation unit is the same as that of the distal fixing member 1114 of the ablation unit. The distal end and the proximal end of the internal support member 1112 are respectively placed in the internal support member openings 11141 in the distal fixing member 1114 of the ablation unit and the proximal fixing member 1113 of the ablation unit to limit the displacement of the internal support member 1112 when it is fixed to the distal fixing member 1114 of the ablation unit and the proximal fixing member 1113 of the ablation unit. In addition, the same spacing is maintained between adjacent internal support member openings 11141 to ensure that the petal branches 111 maintain the same spacing from each other. Coupled with the good fixation of the internal support member 1112 and the distal fixing member 1114 of the ablation unit, the anti-extrusion deformation ability of the ablation unit 11 is further increased.

[0059] Figure 4BAnother structural schematic diagram of the distal fixing member 1114 of the ablation unit. The distal fixing member 1114 of the ablation unit is composed of an outer fixing member 11142 and an inner locking member 11143. Both the outer fixing member 11142 and the inner locking member 11143 are of hollow structures. The outer fixing member 11142 is sleeved outside the inner locking member 11143. The hollow cavity of the inner locking member 11143 is the passage of the inner tube 12. The inner wall of the outer fixing member 11142 is provided with no less than 4 inner bosses 11144 and inner grooves 11145, and the specific quantity matches the number of petal branches 111. The outer wall of the inner locking member 11143 cooperating with the outer fixing member 11142 is provided with no less than 4 outer bosses 11146 and outer grooves 11147, and the specific quantity matches the number of petal branches 111. The hollow structure of the inner locking member 11143 is used to pass through the inner tube 12 and fix with the distal end 114 of the ablation unit. The materials of the distal fixing member 1114 of the ablation unit include but are not limited to various metal materials and polymer materials, and the appearances include but are not limited to cylinders, cuboids, cubes and other shapes. In this embodiment, taking the fixation of the distal end of the internal support member 1112 and the distal fixing member 1114 of the ablation unit as an example, first place the distal end of the internal support member 1112 in the inner groove 11145, and then snap the inner locking member 11143 down into the outer fixing member 11142. Among them, the outer boss 11146 is aligned with the inner boss 11144, and the outer groove 11147 is aligned with the inner groove 11145. Both ends of the internal support member 1112 are respectively accommodated in the spaces defined by the inner groove 11145 and the outer groove 11147. The outer fixing member 11142 and the inner locking member 11143 are mechanically interference-fitted to realize the fixation of the internal support member 1112. It should be noted that the sum of the heights of the outer boss 11146 and the inner boss 11144 is consistent with the total height of the distal fixing member 1114 of the ablation unit, and the groove depths of the outer groove 11147 and the inner groove 11145 are slightly smaller than the outer diameter of the internal support member 1112, so good mechanical interference fit can be achieved.

[0060] The top view after the inner locking member 11143 and the outer fixing member 11142 are fitted is as Figure 4CAs shown, the internal support member 1112 is clamped within the outer groove 11147, and the distance between two adjacent outer grooves 11147 is the width of the outer convex platform 11146. Finally, the distal end 114 of the ablation unit, the ablation unit distal fixing member 1114 and the inner tube 12 are fixed together, and the fixing methods include but are not limited to laser welding, metal welding, and high-temperature hot melting, etc. The ablation unit proximal fixing member 1115 is also composed of an outer fixing member and an inner locking member. Both the outer fixing member and the inner locking member are hollow structures. The outer fixing member is sleeved outside the inner locking member, and the hollow cavity of the inner locking member is the passage of the inner tube. The fixing method of the proximal end of the internal support member 1112 and the ablation unit proximal fixing member 1113 is the same. Due to the interference fit between the inner locking member 11143 and the outer fixing member 11142, the phenomenon that the internal support member 1112 is displaced when fixed to the ablation unit distal fixing member 1114 or the ablation unit proximal fixing member 1115 is restricted. In addition, the distance between two adjacent outer grooves 11147 is the same (the distance is the width of the outer convex platform 11146) to ensure that the distance between two adjacent petal branches 111 is the same. Coupled with the good fixation of the internal support member 1112 to the ablation unit distal fixing member and the ablation unit proximal fixing member, the anti-extrusion deformation ability of the ablation unit 11 is further increased.

[0061] The ablation unit distal fixing member 1114 and the ablation unit proximal fixing member 1115 of the present invention are used to fix the internal support member 1112 and maintain the same distance between two adjacent petal branches 111. The fixing method can be Figure 4A as shown, placing the internal support member 1112 in the internal support member opening 11141 of the ablation unit distal fixing member 1114, or it can be Figure 4B as shown, realizing the fixation of the internal support member 1112 by the interference fit between the outer fixing member 11142 and the inner locking member 11143.

[0062] As Figure 5A and Figure 5B shown, during the assembly and fixing process, the longitudinal projections of the distal end and the proximal end of the internal support member 1112 of the present invention do not coincide, and there is a certain horizontal distance 1117 between the distal end and the proximal end of the internal support member 1112 in the longitudinal direction. When the inner tube 12 is pulled in the proximal direction or pushed in the distal direction of the ablation catheter, the distal end and the proximal end of the internal support member 1112 will each receive acting forces along the inner tube 12 and in opposite directions. Due to the certain horizontal distance 1117 between the distal end and the proximal end of the internal support member 1112 in the longitudinal projection, combined with the offset angle 1115 of the distal end and the offset angle 1116 of the proximal end of the internal support member 1112 relative to the axis of the distal end of the inner tube 12, when the inner tube 12 is pulled or pushed, the distal end and the proximal end of the internal support member 1112 can more easily deform along their respective offset angles, so that it can be more easily achievedFigure 1B The unfolding of the flower-shaped morphology shown, and effectively reducing the risk of breakage of the catheter petal branches.

[0063] In addition, during the process of the ablation catheter unfolding from the basket shape to the flower shape, if the distal end and the proximal end of the internal support member 1112 coincide in the longitudinal projection, when the distal end 114 of the ablation unit 11 touches the proximal end 115 of the ablation unit 11, it may cause the distal end and the proximal end of the internal support member 1112 to squeeze each other, making the formed petals have a certain angle with the horizontal plane, resulting in the upper part of the ablation electrodes on the petals being suspended and unable to effectively contact the lesion tissue, thereby reducing the effectiveness of ablation. Based on the fact that there is a certain horizontal distance 1117 between the distal end and the proximal end of the internal support member 1112 in the longitudinal projection, when the distal end 114 of the ablation unit 11 touches the proximal end 115 of the ablation unit 11, the present utility model can effectively prevent the distal end and the proximal end of the internal support member 1112 from squeezing each other, which helps each petal to be formed on the same plane, increases the effective contact area between the ablation electrodes and the lesion tissue, and thus improves the effectiveness of ablation.

[0064] The above description of the present application is intended to enable those skilled in the art to understand the content of the present utility model and implement it, and it cannot be used to limit the protection scope of the present utility model. Any equivalent changes or modifications made according to the spirit and essence of the present utility model should be covered within the protection scope of the present utility model.

Claims

1. An ablation catheter, comprising an ablation component, an operating component and a connecting component, wherein: The ablation component is composed of an ablation unit, an inner tube and an outer tube, the inner tube passes through the lumen of the outer tube and extends to the outside of the distal end of the lumen, the distal end of the ablation unit is fixedly connected to the inner tube, the proximal end of the ablation unit is fixedly connected to the distal end of the outer tube, the inner tube is configured to move along the longitudinal axis of the outer tube to achieve the conversion of the configuration of the ablation unit, the connecting component includes an electric plug, the operating component includes a handle and a telescopic deformation adjustment mechanism arranged on the handle, the telescopic deformation adjustment mechanism is used to achieve the configuration conversion of the ablation unit, and is characterized in that the ablation unit includes a plurality of petal branches, a plurality of ablation electrodes fixed on the petal branches and a plurality of wires, the ablation electrodes are connected to the electric plug via the wires The petal branch is composed of an external sleeve and an internal support member arranged in the external sleeve, the proximal ends of the external sleeve and the internal support member are fixedly connected to the distal end of the outer tube through the proximal end fixing member of the ablation unit, and the distal ends of the external sleeve and the internal support member are fixedly connected to the inner tube through the distal end fixing member of the ablation unit, the hardness of the two end parts of the internal support member is greater than the hardness of the middle section, and the ablation unit has three configurations, the first configuration is a contracted state of the petal branch of the ablation unit close to the longitudinal axis of the inner tube; the second configuration is a basket shape formed by the petal branch of the ablation unit expanding outward along the radial direction of the inner tube; the third configuration is a flower shape formed by the proximal and distal ends of the petal branch of the ablation unit approaching each other.

2. The ablation catheter according to claim 1, characterized in that: The hardness of the inner support member gradually decreases from both ends to the middle.

3. The ablation catheter according to claim 2, characterized in that: The inner support is made of a variable stiffness shape memory alloy.

4. The ablation catheter according to claim 2, characterized in that: The inner support member is made of a shape memory alloy, and the outer diameter of the inner support member is variable.

5. The ablation catheter according to claim 1, characterized in that: The proximal fixing part of the ablation unit and the distal fixing part of the ablation unit are hollow structures, and a plurality of openings are arranged on the tube walls of the proximal fixing part of the ablation unit and the distal fixing part of the ablation unit. The two ends of the internal support member are respectively inserted into the openings of the proximal fixing part of the ablation unit and the distal fixing part of the ablation unit, and the hole spacing between two adjacent openings is the same, and the number of the openings matches the number of the petal branches.

6. The ablation catheter according to claim 1, characterized in that: The proximal fixing part of the ablation unit and the distal fixing part of the ablation unit are composed of an external fixing part and an internal locking part, both of which are hollow structures, the external fixing part is sleeved outside the internal locking part, the hollow cavity of the internal locking part is an inner tube channel, the inner wall of the external fixing part is provided with a plurality of inner bosses and inner grooves, the outer wall of the internal locking part is provided with a plurality of outer bosses and outer grooves, the outer bosses are aligned with the inner bosses, the outer grooves are aligned with the inner grooves, the two ends of the internal support part are respectively accommodated in the space defined by the inner grooves and the outer grooves, the external fixing part and the internal locking part are mechanically interference fit to realize the fixation of the internal support part, the number of the inner bosses and inner grooves and the number of the outer bosses and outer grooves match the number of the petal branches.

7. The ablation catheter according to claim 6, characterized in that: The sum of the heights of the outer boss and the inner boss is equal to the height of the distal fixing piece of the ablation unit or the proximal fixing piece of the ablation unit.

8. The ablation catheter according to claim 1, characterized in that: After pre-forming, the distal end of the internal support is offset relative to the axis of the inner tube, the proximal end of the internal support is offset relative to the axis of the inner tube in a direction opposite to the direction of the distal end offset, and the middle part of the internal support has an arc structure.

9. The ablation catheter according to claim 8, characterized in that: The offset angle of the distal end of the inner support is equal to the offset angle of the proximal end of the inner support.

10. The ablation catheter according to claim 9, characterized in that: The projections of the distal end and the proximal end of the internal support member in the longitudinal direction do not overlap and have a certain horizontal spacing.

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