Radiofrequency ablation catheter and radiofrequency ablation device

Abstract

The embodiment of the present application provides a kind of radiofrequency ablation catheter and radiofrequency ablation equipment.The radiofrequency ablation catheter includes the electrode support that can be radially contracted and expanded, connecting pipe and center wire;The proximal end of connecting pipe is connected with the distal end of electrode support, and connecting pipe has first lumen through its proximal end and distal end;Center wire is movably threaded in electrode support and first lumen;First limiting portion is provided on center wire, and first limiting portion is located in first lumen, and the inner wall of first lumen is correspondingly provided with second limiting portion;When first limiting portion and second limiting portion abut, and center wire moves from distal end to proximal end direction, electrode support is switched from contracted state to expanded state.The technical scheme provided by the present application can reduce the risk of damaging blood vessels, improve the accuracy of center wire selecting target branch blood vessels, and thus improve the ablation efficiency of radiofrequency ablation.

Description

Technical Field

[0001] The present application relates to the technical field of radiofrequency ablation, and in particular to a radiofrequency ablation catheter and a radiofrequency ablation device. Background Art

[0002] Radiofrequency ablation (RFA) technology is currently widely used in the medical field. RF ablation catheters equipped with multiple electrodes can significantly improve RF efficiency. RF ablation, which targets overactive renal artery sympathetic nerves, is a typical treatment for refractory hypertension. This procedure utilizes a catheter equipped with RF electrodes, which is inserted through the radial or femoral artery to reach the target location for sympathetic nerve ablation, effectively treating hypertension.

[0003] Before the procedure begins, the radiofrequency ablation catheter must be inserted into the blood vessel using a central wire. The central wire is then used to guide the catheter into the target branch vessel for ablation. Once the catheter is positioned for ablation, the central wire is withdrawn, and radiofrequency ablation is then performed. If multiple target ablation areas need to be ablated during the same procedure, the central wire must be inserted and removed multiple times, which is cumbersome and inconvenient, and can increase intraoperative risks.

[0004] Of course, there are also technical solutions in the existing technology that combine a central wire with radiofrequency ablation. The distal end of the central wire is provided with a limiting structure. The central wire can move axially relative to the catheter and will not separate from the catheter under the action of the limiting structure. The distal end of the central wire extends outside the distal end of the catheter, which can enter the target branch vessel to perform branch superselection. When the limiting structure of the central wire abuts the end of the electrode stent, the central wire is continued to be withdrawn, which can also realize the expansion function of the electrode stent. However, in actual use, there are still problems with low branch superselection accuracy and easy damage to blood vessels. Summary of the Invention

[0005] The present application provides a radiofrequency ablation catheter and a radiofrequency ablation device, which can reduce the risk of damaging blood vessels, improve the accuracy of the central wire in selecting target branch blood vessels, and thus improve the ablation efficiency of radiofrequency ablation.

[0006] This application is achieved through the following technical solutions:

[0007] In the first aspect, an embodiment of the present application provides a radiofrequency ablation catheter, which includes an electrode holder that can radially contract and expand, a connecting tube and a center wire; the proximal end of the connecting tube is connected to the distal end of the electrode holder, and the connecting tube has a first lumen running through its proximal and distal ends; the center wire is movably arranged in the electrode holder and the first lumen; wherein a first limiting portion is provided on the center wire, the first limiting portion is located in the first lumen, and a second limiting portion is correspondingly provided on the inner wall of the first lumen; when the first limiting portion abuts against the second limiting portion, and the center wire moves from the distal end to the proximal end, the electrode holder switches from a contracted state to an expanded state.

[0008] In this embodiment, a central wire is movably disposed between the electrode holder and the first lumen, with the distal end of the central wire extending outside the connecting tube to guide the radiofrequency ablation catheter into the target branch vessel, thereby achieving branch superselection. A first stopper is provided on the central wire, and a second stopper is correspondingly provided on the inner wall of the first lumen. After the first and second stoppers engage and block, further retraction of the central wire allows the electrode holder to expand, allowing the electrodes on the electrode holder to adhere to the wall for radiofrequency ablation. By locating both the first and second stoppers within the first lumen, compared to a method in which a blocking structure is provided at the distal end of the central wire and abuts the end faces of the electrodes, when using the distal end of the central wire for branch superselection, the first stopper of the central wire is not exposed outside the connecting tube because it is located within the first lumen. This results in a relatively smaller distal end of the central wire, making it less likely to scratch the target branch vessel when selecting the target branch vessel, thereby reducing the risk of vascular damage. Moreover, since the distal end of the central wire is smaller in size, the central wire is less likely to clash with or get stuck on the wall of the branch vessel. The central wire can be easily rotated or pulled back and forth, and the movement or rotation of the central wire is smoother. The central wire is more controllable and can enter the target branch vessel more easily, which reduces the difficulty of the central wire in selecting the target branch vessel, improves the accuracy of the central wire branch superselection, and thereby improves the efficiency of radiofrequency ablation.

[0009] According to some embodiments of the present application, a third limiting portion is provided on the central wire, and the third limiting portion and the first limiting portion are respectively located on opposite sides of the second limiting portion; when the third limiting portion is abutted against the second limiting portion and the central wire moves from the proximal end to the distal end, the electrode bracket can switch from an expanded state to a contracted state.

[0010] In the above solution, by providing a third limiting portion on the central wire, the third limiting portion can cooperate with the second limiting portion. When the central wire moves from the proximal end to the distal end, on the one hand, it can assist the electrode holder by applying a contraction force toward the distal end to the electrode holder, causing the electrode holder to switch to a contracted state, making the radial dimension of the electrode holder smaller after contraction, which is beneficial for the movement of the electrode holder within the blood vessel. This avoids the limited resetting ability of the electrode holder itself, resulting in poor contraction effect of the electrode holder, which in turn increases the radial dimension of the electrode holder, causing the radiofrequency ablation catheter to move poorly within the blood vessel or even scratch the blood vessel. On the other hand, the third limiting portion cooperates with the second limiting portion to limit the extended length of the distal end of the central wire, preventing the central wire from being separated from the connecting tube.

[0011] According to some embodiments of the present application, the central wire includes a guidewire body and a soft guidewire disposed at the distal end of the guidewire body, and the first limiting portion is disposed on the guidewire body.

[0012] In the above scheme, the center wire includes a guidewire body and a soft guidewire. When the center wire selects the target branch vessel through the soft guidewire at its distal end, on the one hand, after the soft guidewire contacts the vessel wall, it will adaptively deform to follow the curvature of the vessel wall, giving the soft guidewire a guiding function, facilitating the center wire's passage through the soft guidewire into the corresponding branch vessel, thereby improving the efficiency of branch superselection. On the other hand, the soft guidewire is made of a flexible material. After the soft guidewire contacts the vessel wall, the soft guidewire deforms, avoiding rigid contact between the center wire and the vessel, thereby reducing the probability of damage to the vessel.

[0013] According to some embodiments of the present application, along the radial direction of the soft guide wire, the soft guide wire includes an inner layer, an intermediate layer and an outer layer from the inside to the outside, the inner layer is made of nickel-titanium grinding alloy wire, the intermediate layer is a high-density metal alloy spring, and the outer layer is a stainless steel spring. In the above scheme, since the nickel-titanium grinding alloy wire is a superelastic shape memory alloy, it cannot be directly shaped. The springs of the intermediate layer and the outer layer are plastically deformable, and the shape of the inner layer's extremely fine grinding wire can be changed by adjusting the shape of the springs of the intermediate layer and the outer layer, thereby achieving the surgeon's clinical shaping requirements. The soft guide wire has its own angle, and when the doctor wants to enter different blood vessel branches, there will be a need to adjust the angle of the front end of the center wire. The angle of the center wire can be changed to meet the requirements of entering different blood vessel branches, thereby improving the efficiency of branch superselection.

[0014] According to some embodiments of the present application, the connecting tube includes a polymer material layer and an elastic structure layer. The elastic structure layer is embedded inside the polymer material layer, and the elastic structure layer encloses and defines a first cavity.

[0015] In the above-described solution, the polymer material layer constitutes the main body of the connecting tube, giving it a certain strength and bending and deformation capability, allowing it to adapt to the tortuous path of the blood vessel. An elastic structural layer is provided within the connecting tube, enclosing the first lumen. When the connecting tube bends and deforms to adapt to the blood vessel, the elastic structural layer provides support to prevent the first lumen from being flattened or squeezed, thereby ensuring that the central filament has sufficient space to move within the first lumen, allowing the central filament to move smoothly (rotate or move axially) within the first lumen without affecting the branching superselection function of the central filament.

[0016] According to some embodiments of the present application, the elastic structural layer is a metal woven mesh layer.

[0017] In the above scheme, the elastic structural layer is formed by adopting a metal braided mesh, which encloses the first cavity. The metal braided layer can provide support performance for the first cavity. When the connecting tube bends and deforms due to adapting to the blood vessel, the first cavity is not easily flattened or squeezed and deformed under the support of the metal braided mesh, thereby ensuring that the central wire has sufficient space for movement in the first cavity, which is conducive to the smooth movement of the central wire in the first cavity and is not easy to affect the branch superselection function of the central wire.

[0018] According to some embodiments of the present application, the elastic structural layer is a spring.

[0019] In the above scheme, by adopting the elastic structural layer as a spring, due to the characteristics of the spring itself, the spring provides a certain elasticity and support performance to the connecting tube, so that the connecting tube not only has a certain toughness, but also has better bending performance. After the connecting tube enters the branch of the blood vessel, on the one hand, the spring can further enhance the bending performance and deformation recovery performance of the connecting tube, so that the connecting tube can more easily adapt to the bending of the branch blood vessel and adaptively bend and deform, reducing the probability of the connecting tube damaging the blood vessel. When the connecting tube loses the compression effect of the blood vessel wall, the connecting tube can be more easily and quickly reset under the reset action of the spring, thereby enhancing the bending performance and reset ability of the connecting tube. On the other hand, the spring encloses to form a first lumen. When the connecting tube bends and deforms due to adapting to the blood vessel, under the support of the spring, the first lumen is not easily flattened or squeezed, thereby ensuring that the central wire has sufficient space for movement in the first lumen, which is conducive to the smooth movement of the central wire in the first lumen and is not easy to affect the branch superselection function of the central wire.

[0020] According to some embodiments of the present application, a lubricating layer is provided on the inner side of the elastic structural layer, and the lubricating layer is used to reduce the friction force when the central wire and the elastic structural layer slide relative to each other.

[0021] In the above scheme, a lubricating layer is provided on the inner side of the elastic structural layer, and the lubricating layer is in contact with the center wire. Compared with the contact between the center wire and the elastic structural layer, the lubricating layer can reduce the friction force between the center wire and the elastic structural layer during relative sliding, so that the movement of the center wire in the first cavity is smoother, the adjustment of the center wire is smoother, and it is not easy to interfere with or hinder the elastic structural layer.

[0022] According to some embodiments of the present application, the lubricating layer is a polytetrafluoroethylene etched tube.

[0023] In the above scheme, by using a polytetrafluoroethylene etched tube as the lubricating layer, and compared with applying a lubricating coating on the inner wall of the first lumen, the polytetrafluoroethylene etched tube has better durability. In this way, the outer wall of the central wire contacts the inner wall of the polytetrafluoroethylene etched tube, and the inner wall of the polytetrafluoroethylene etched tube is relatively smooth. The central wire can move more smoothly in the first lumen, and the central wire can more flexibly select the target branch blood vessel.

[0024] According to some embodiments of the present application, a connector is provided at the distal end of the electrode holder, the connector is embedded in the proximal end of the connecting tube, and the connector is hot-melt-connected to the polymer material layer of the connecting tube.

[0025] In the above scheme, a connector is provided at the distal end of the electrode holder, which acts as an intermediate transition, so that the mesh tube of the electrode holder can be pre-connected with the connector as a whole, and then hot-melt-connected with the polymer material layer of the connecting tube, thereby reducing the difficulty of connecting the electrode holder and the connecting tube.

[0026] According to some embodiments of the present application, the connecting member is an annular metal sheet.

[0027] In the above solution, the metal sheet used as the connector facilitates welding and fixing to the mesh tube of the electrode holder, resulting in a stable connection. Furthermore, the annular structure of the connector provides ample circumferential welding area between the connector and the elastic structure layer, ensuring sufficient connection strength between the elastic structure layer and the connector.

[0028] According to some embodiments of the present application, the elastic structural layer is welded to the connecting piece.

[0029] In the above solution, during the assembly of the connecting pipe, the elastic structural layer can be welded to the connecting piece first, achieving a pre-connection between the elastic structural layer and the connecting piece. This prevents the elastic structural layer from shifting during the subsequent hot-melt process of the connecting pipe's polymer material layer, thereby facilitating precise molding of the connecting pipe. Furthermore, welding the elastic structural layer to the connecting piece further enhances the stability of the elastic structural layer within the connecting pipe.

[0030] According to some embodiments of the present application, the inner diameter of the first lumen is the same from the proximal end to the distal end, and the outer diameter of the connecting tube gradually decreases.

[0031] In the above solution, the outer diameter of the connecting tube is gradually reduced from the proximal end to the distal end, and the connecting tube is tapered. The distal end of the connecting tube serves as a guide, which is more conducive to the connecting tube entering the target branch blood vessel.

[0032] According to some embodiments of the present application, the radiofrequency ablation catheter also includes a catheter, which is connected to one end of the electrode holder away from the connecting tube. The catheter has a second lumen extending along its axial direction, and the central wire is sequentially arranged in the second lumen, the electrode holder and the first lumen.

[0033] In the above scheme, the catheter can provide the function of accommodating various wires or central wires of the radiofrequency ablation catheter. The second lumen of the catheter can be used for the central wire to pass through. After the central wire passes through the second lumen, the electrode bracket and the first lumen in sequence, the central wire extends out of the connecting tube to provide the function of branch superselection.

[0034] According to some embodiments of the present application, the radiofrequency ablation catheter further includes an operating handle, which is disposed on the proximal side of the catheter and connected to the proximal end of the central wire for controlling the movement of the central wire relative to the catheter.

[0035] In the above scheme, through the setting of the operating handle, the operating handle is connected to the proximal end of the central wire. The operating handle plays the role of controlling the movement of the central wire. It can drive the central wire to move or rotate axially relative to the catheter according to needs, thereby realizing the distal rotation of the central wire to explore the target branch blood vessel and realize the function of branch superselection.

[0036] In a second aspect, an embodiment of the present application further provides a radiofrequency ablation device, which includes the radiofrequency ablation catheter of any of the aforementioned embodiments.

[0037] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 A schematic diagram of the structure of an electrode stent in an expanded state in a radiofrequency ablation catheter provided in some embodiments of the present application;

[0040] Figure 2 A schematic diagram of the structure of an electrode support in a retracted state in a radiofrequency ablation catheter provided in some embodiments of the present application;

[0041] Figure 3 for Figure 1 Cross-sectional view of AA;

[0042] Figure 4 for Figure 3 A is an enlarged schematic diagram;

[0043] Figure 5 A schematic structural diagram of a radiofrequency ablation catheter provided in some embodiments of the present application;

[0044] Figure 6 for Figure 5 A magnified schematic diagram of B in the middle;

[0045] Figure 7 A schematic diagram of the structure of the operation handle and the central wire in the radiofrequency ablation catheter provided in some embodiments of the present application;

[0046] Figure 8 for Figure 7 Cross-sectional view of AA;

[0047] Figure 9 for Figure 8 An enlarged diagram of the operating handle.

[0048] Icons: 100-RF ablation catheter; 10-catheter; 11-second lumen; 20-electrode holder; 21-connecting piece; 22-electrode; 30-connecting tube; 31-polymer material layer; 32-elastic structure layer; 33-lubricating layer; 34-first lumen; 35-second limiting part; 40-center wire; 41-first limiting part; 42-third limiting part; 43-guidewire body; 44-soft guidewire; 441-inner layer; 442-middle layer; 443-outer layer; 50-operating handle; 51-handle; 511-installation cavity; 52-operating piece; 521-main body; 522-rotating handle; 523-fixing piece. DETAILED DESCRIPTION

[0049] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0050] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0051] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0052] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0053] There are also technical solutions in the prior art that combine a central wire with radiofrequency ablation, such as the patent with publication number CN111513837B. In this solution, a limiting structure is set at the distal end of the central wire. The central wire can move axially relative to the catheter and will not separate from the catheter under the action of the limiting structure. The distal end of the central wire extends outside the distal end of the catheter, which can enter the target branch blood vessel to perform branch superselection. When the limiting structure of the central wire abuts the end of the electrode stent, the central wire continues to be withdrawn, which can also realize the expansion function of the electrode stent. However, in actual use, there are still problems with low branch superselection accuracy and easy damage to blood vessels.

[0054] Specifically, a blocking structure is provided at the distal end of the central wire, and the blocking structure at the distal end of the central wire abuts and cooperates with the end face of the distal end of the electrode holder, thereby also realizing the expansion function of the electrode holder. Although the distal end of the central wire can be used to probe into the target branch vessel to achieve the function of branch superselection, when the distal end of the central wire is used for branch superselection, due to the narrow and tortuous space of the branch vessel, the blocking structure at the distal end of the central wire increases the size of the distal end of the central wire. The blocking structure of the central wire is prone to abutment or obstruction with the vessel wall, which not only affects the forward and backward movement of the central wire, but also when the central wire is rotated to select the corresponding branch vessel, the blocking structure is prone to contact with the vessel wall, affecting the rotation of the central wire or the rotation accuracy, making the controllability of the central wire lower, affecting the accuracy of branch superselection, and even causing damage to the vessel.

[0055] For example, when the proximal end of the center wire rotates 50° along the preset direction, because the blocking structure at the distal end of the center wire may abut against the blood vessel wall, the rotation amplitude of the distal end of the center wire may be less than 50°, that is, the distal end of the center wire may be twisted. Then, when the angle of the center wire is further rotated 50° along the preset direction, the distal end of the center wire suddenly overcomes the twisted state under the action of the rotational force, so that the distal end of the center wire recovers. Then, the rotation angle of the distal end of the center wire is greater than 50°, and the center wire will suddenly swing too much in this process, making the center wire or the blocking structure at the distal end of the center wire easily damage the blood vessel. That is, when the blocking structure is set at the distal end of the center wire, the center wire is prone to uncontrollable swing amplitude during the adjustment process, the branch of the center wire is overselected with low precision, and is easy to damage the blood vessel.

[0056] In view of this, the present application embodiment provides a radiofrequency ablation catheter, please refer to Figures 1 to 4 The radiofrequency ablation catheter 100 includes an electrode holder 20 that can be radially contracted and expanded, a connecting tube 30 and a center wire 40; the proximal end of the connecting tube 30 is connected to the distal end of the electrode holder 20, and the connecting tube 30 has a first lumen 34 that runs through its proximal and distal ends; the center wire 40 is movably arranged in the electrode holder 20 and the first lumen 34; wherein, a first limiting portion 41 is provided on the center wire 40, and the first limiting portion 41 is located in the first lumen 34, and a second limiting portion 35 is correspondingly provided on the inner wall of the first lumen 34; when the first limiting portion 41 abuts against the second limiting portion 35, and the center wire 40 moves from the distal end to the proximal end, the electrode holder 20 switches from the contracted state to the expanded state, Figure 1 The schematic diagram of the structure of the electrode stent in the expanded state is shown in FIG. Figure 2 FIG. 3 shows a schematic diagram of the structure of the electrode holder in a contracted state.

[0057] In this embodiment, a central wire 40 is movably disposed between the electrode holder 20 and the first lumen 34. The distal end of the central wire 40 extends beyond the connecting tube 30, guiding the radiofrequency ablation catheter 100 into the target branch vessel and enabling branch superselection. A first stopper 41 is provided on the central wire 40, and a second stopper 35 is correspondingly provided on the inner wall of the first lumen 34. After the first stopper 41 and the second stopper 35 engage, further retraction of the central wire 40 expands the electrode holder 20, allowing the electrodes 22 on the electrode holder 20 to adhere to the wall for radiofrequency ablation. By embedding both the first limiting portion 41 and the second limiting portion 35 within the first lumen 34, compared to a method in which a blocking structure is provided at the distal end of the center wire 40 and abuts the end surface of the electrode 22, when using the distal end of the center wire 40 for branch superselection, the first limiting portion 41 of the center wire 40 is embedded within the first lumen 34 and does not protrude outside the connecting tube 30. This makes the distal end of the center wire 40 relatively smaller, making it less likely to scratch the target branch vessel when selecting the target branch vessel, thereby reducing the risk of vessel damage. Furthermore, due to the smaller distal end of the center wire 40, the center wire 40 is less likely to clash with or become stuck on the branch vessel wall, allowing the center wire 40 to be easily rotated or pulled back and forth, resulting in smoother movement or rotation of the center wire 40 and greater controllability. The center wire 40 can more easily enter the target branch vessel, reducing the difficulty of the center wire 40 selecting the target branch vessel, improving the accuracy of the center wire 40 branch superselection, and thereby improving the efficiency of radiofrequency ablation.

[0058] The electrode holder 20 can be shaped like a mesh tube. This is a mesh structure of a certain length, formed by weaving a single or multiple wires in a spiral pattern in both forward and reverse directions. During expansion and adherence, the braided wires interwoven around each node of the electrode holder 20 provide support, making it less likely to collapse.

[0059] The electrode holder 20 has a contracted state and an expanded state. One or more electrodes 22 are attached to the braided wire in the middle section of the electrode holder 20. This middle section, activated by the central wire 40, can expand outward, allowing the electrodes 22 on the holder 20 to adhere to the blood vessel wall. The electrodes 22 can be block electrodes or ring electrodes. The outer surface of the electrodes 22 is higher than that of the braided wire, ensuring full contact with the vessel wall and improving adhesion.

[0060] The braided wires of the electrode holder 20 can be made of metal or polymer materials, such as stainless steel, nickel-titanium, or cobalt-nickel. By pulling the center wire 40 until the first stopper 41 on the center wire 40 abuts the second stopper 35 in the first lumen 34, the center wire 40 is then pulled proximally. The center wire 40 can then move the electrode holder 20 proximally, expanding the electrode holder 20 and adjusting the adhesion of the electrodes 22 thereto. This allows the electrode holder 20 to be adapted for use in vessels of varying diameters.

[0061] The proximal end refers to the end closest to the operator, and the distal end refers to the end further away from the operator. Taking the proximal and distal ends of the connecting tube 30 as an example, the proximal end of the connecting tube 30 refers to the end closest to the operator, and the distal end of the connecting tube 30 refers to the end further away from the operator. The proximal and distal ends are located at the two axial ends of the connecting tube 30, respectively.

[0062] The connecting tube 30 is a terminal structure located at the distal end of the electrode holder 20. The proximal end of the connecting tube 30 is fixedly connected to the distal end of the electrode holder 20. The first lumen 34 is the internal lumen of the connecting tube 30, through which the center wire 40 is inserted. The first lumen 34 extends through both the proximal and distal ends of the connecting tube 30.

[0063] The distal end of the center wire 40 can be straight, curved, or arc-shaped. Optionally, the distal end of the center wire 40 is curved, i.e., it has an elbow. The center wire 40 is movably disposed within the first lumen 34 of the electrode holder 20 and the connecting tube 30, meaning that the center wire 40 can move or slide axially within the first lumen 34 and can also rotate about its central axis within the first lumen 34.

[0064] When using the distal end of the center wire 40 to select the target branch vessel, the center wire 40 can move axially to adjust the extension length of the distal end of the center wire 40 outside the connecting tube 30 to facilitate the selection and entry of the target branch vessel. The center wire 40 can also rotate around its central axis to allow the elbow at the distal end of the center wire 40 to rotate, so as to facilitate more flexible selection of the target branch vessel.

[0065] The first limiting portion 41 is a protruding structure protruding from the outer peripheral surface of the center wire 40. The material of the first limiting portion 41 can be metal or other materials. In this embodiment, the first limiting portion 41 is a metal sheet and can be welded and fixed to the center wire 40.

[0066] The outer diameter of the first stopper 41 is smaller than the inner diameter of the first lumen 34. The first stopper 41 can rotate with the center wire 40 within the first lumen 34 or move axially along the connecting tube 30. The second stopper 35 is a protruding structure provided within the first lumen 34 of the connecting tube 30 and protruding from the inner wall of the first lumen 34.

[0067] According to some embodiments of the present application, a third limiting portion 42 is provided on the central wire 40, and the third limiting portion 42 and the first limiting portion 41 are respectively located on opposite sides of the second limiting portion 35; when the third limiting portion 42 is abutted against the second limiting portion 35 and the central wire 40 moves from the proximal end to the distal end, the electrode holder 20 can switch from an expanded state to a contracted state.

[0068] The third limiting portion 42 and the first limiting portion 41 are both located within the first cavity 34 and on opposite sides of the second limiting portion 35. The third limiting portion 42 and the first limiting portion 41 may have the same or different structures. The third limiting portion 42 is a raised structure protruding from the outer circumference of the center wire 40. The material of the third limiting portion 42 can be metal or other materials. In this embodiment, the third limiting portion 42 is a metal sheet and is welded to the center wire 40.

[0069] By providing a third limiting portion 42 on the center wire 40, the third limiting portion 42 can cooperate with the second limiting portion 35. When the center wire 40 moves from the proximal end to the distal end, on the one hand, it can assist the electrode holder 20 by applying a contraction force toward the distal end to the electrode holder 20, causing the electrode holder 20 to switch to a contracted state. This makes the radial dimension of the electrode holder 20 smaller after contraction, which is beneficial for the movement of the electrode holder 20 within the blood vessel. This avoids the limited reset ability of the electrode holder 20, which leads to poor contraction of the electrode holder 20 and thus increases the radial dimension of the electrode holder 20, resulting in the radiofrequency ablation catheter 100 moving poorly within the blood vessel or even scratching the blood vessel. On the other hand, the third limiting portion 42 cooperates with the second limiting portion 35 to limit the extended length of the distal end of the center wire 40, preventing the center wire 40 from being separated from the connecting tube 30.

[0070] According to some embodiments of this application, please refer to Figure 1 The center wire 40 includes a guide wire body 43 and a soft guide wire 44 arranged at the distal end of the guide wire body 43 , and the first limiting portion 41 is arranged on the guide wire body 43 .

[0071] The guide wire body 43 is a metal wire, such as nickel-titanium grinding alloy wire. During the motion of the center wire 40, a soft guide wire 44 is positioned at or remains on one side of the distal end outside the connecting tube 30 all the time.

[0072] The angle between the soft guidewire 44 and the guidewire body 43 is 45 degrees. The shape of the distal end of the soft guidewire 44 can be a straight line, a curve, or an arc, including but not limited to an L-shape, a straight line, or a circular arc, so that the target branch vessel can be selected more flexibly. Optionally, the distal end of the soft guidewire 44 is arc-shaped.

[0073] The angle between the soft guide wire 44 and the guide wire body 43 can be 0° to 90°. That is, the angle between the soft guide wire 44 and the guide wire body 43 can be 10°, 20°, 30°, 40°, 45°, 50°, 55°, 60°, 70° or 80°.

[0074] The center wire 40 includes a guide wire body 43 and a soft guide wire 44. When the center wire 40 selects a target branch vessel through the soft guide wire 44 at its distal end, on the one hand, after the soft guide wire 44 contacts the vessel wall, it will adaptively deform to follow the curvature of the vessel wall, giving the soft guide wire 44 a guiding function, facilitating the center wire 40 to enter the corresponding branch vessel through the soft guide wire 44, thereby improving the efficiency of branch superselection. On the other hand, the soft guide wire 44 is made of a flexible material. After the soft guide wire 44 contacts the vessel wall, the soft guide wire 44 deforms, preventing the center wire 40 from rigidly contacting the vessel and reducing the probability of damage to the vessel.

[0075] According to some embodiments of this application, please combine Figure 5 and Figure 6 Along the radial direction of the soft guide wire 44, the soft guide wire 44 includes an inner layer 441, a middle layer 442 and an outer layer 443 from the inside to the outside. The inner layer 441 is made of nickel-titanium ground alloy wire, the middle layer 442 is a high-density metal alloy spring, and the outer layer 443 is a stainless steel spring.

[0076] The inner layer 441 is a shape memory alloy (nickel-titanium alloy), and the middle layer 442 can be a development-enhanced high-density metal alloy spring, such as platinum-tungsten or platinum-nickel. The outer layer 443 is a stainless steel spring (304 or 316 stainless steel). Of course, the guidewire body 43 can be a single-layer structure, that is, the guidewire body is made of a nickel-titanium ground alloy wire, the same material as the inner layer 441. The inner layer 441 of the soft guidewire 44 is integrally formed with the guidewire body 43.

[0077] Because the nickel-titanium grinding alloy wire of the inner layer 441 is a superelastic shape memory alloy, it cannot be directly shaped. The springs of the middle layer 442 and the outer layer 443 are plastically deformable. By adjusting the shaping of the springs of the middle layer 442 and the outer layer 443, the shape of the extremely fine grinding wire of the inner layer 441 can be driven to change, thereby achieving the surgeon's clinical shaping requirements. The soft guide wire 44 has its own angle. When the doctor wants to enter different blood vessel branches, he will need to adjust the angle of the front end of the central wire 40. The angle of the central wire 40 can be changed to meet the requirements of entering different blood vessel branches, improving the efficiency of branch superselection.

[0078] According to some embodiments of this application, please refer to Figure 4 The connecting tube 30 includes a polymer material layer 31 and an elastic structure layer 32 . The elastic structure layer 32 is embedded in the inner side of the polymer material layer 31 . The elastic structure layer 32 encloses and defines a first cavity 34 .

[0079] The polymer material layer 31 may be made of TPU or PEBAX. TPU (Thermoplastic Polyurethanes) is a type of elastomer that can be plasticized by heating and dissolved by solvents. It has excellent comprehensive properties such as high strength, high toughness, wear resistance, and oil resistance, and has the advantage of good processing performance.

[0080] PEBAX (Poly Ether Block Amide) is composed of regular linear hard polyamide segments embedded with soft polyether segments.

[0081] The elastic structural layer 32 refers to a structural layer that can provide a certain rigidity to the first cavity 34 . The elastic structural layer 32 can be made of various materials. For example, the elastic structural layer 32 can be made of a spring or a metal braided layer.

[0082] The polymer material layer 31 constitutes the main material of the connecting tube 30, giving the connecting tube 30 a certain strength and bending deformation ability, which can adapt to the tortuous path of the blood vessel. The elastic structural layer 32 is provided within the connecting tube 30, and the elastic structural layer 32 encloses and forms the first lumen 34. When the connecting tube 30 bends and deforms to adapt to the blood vessel, the first lumen 34 is not easily flattened or squeezed out of shape under the support of the elastic structural layer 32, thereby ensuring that the central wire 40 has sufficient space for movement within the first lumen 34. The central wire 40 can move smoothly (rotate or move axially) within the first lumen 34, and it is not easy to affect the branch superselection function of the central wire 40.

[0083] According to some embodiments of the present application, the elastic structure layer 32 is a metal woven mesh layer.

[0084] The metal braided mesh layer may be a mesh structure woven from metal wires. The metal braided mesh layer may provide auxiliary support for the first cavity 34 , thereby reducing the probability of the first cavity 34 being flattened.

[0085] By adopting the elastic structural layer 32 as a metal braided layer mesh, the metal braided layer mesh encloses the first lumen 34, and the metal braided layer can provide support performance for the first lumen 34. When the connecting tube 30 bends and deforms due to adapting to the blood vessels, under the support of the metal braided layer mesh, the first lumen 34 is not easily flattened or squeezed and deformed, thereby ensuring that the central wire 40 has sufficient space for movement in the first lumen 34, which is conducive to the smooth movement of the central wire 40 in the first lumen 34 and is not easy to affect the branch superselection function of the central wire 40.

[0086] According to some embodiments of the present application, the elastic structural layer 32 is a spring. Figure 4 The diagram shows a case where the elastic structural layer 32 is a spring.

[0087] By using the elastic structural layer 32 as a spring, due to its own characteristics, the spring provides a certain elasticity and support performance to the connecting tube 30, making the connecting tube 30 not only have a certain toughness, but also better bending performance. After the connecting tube 30 enters the branch of the blood vessel, on the one hand, the spring can further enhance the bending performance and deformation recovery performance of the connecting tube 30, making it easier for the connecting tube 30 to adapt to the curvature of the branch blood vessel and adaptively bend and deform, reducing the probability of the connecting tube 30 damaging the blood vessel. When the connecting tube 30 loses the compressive effect of the blood vessel wall, the connecting tube 30 can be more easily and quickly reset under the reset action of the spring, thereby enhancing the bending performance and reset ability of the connecting tube 30. On the other hand, the spring encloses the first lumen 34. When the connecting tube 30 bends and deforms due to adapting to the blood vessel, the first lumen 34 is not easily flattened or squeezed out of shape under the support of the spring, thereby ensuring that the center wire 40 has sufficient space for movement within the first lumen 34, which is conducive to the smooth movement of the center wire 40 within the first lumen 34 and is not likely to affect the branch superselection function of the center wire 40.

[0088] According to some embodiments of this application, please continue to refer to Figure 4 A lubricating layer 33 is provided on the inner side of the elastic structural layer 32 , and the lubricating layer 33 is used to reduce the friction force when the center wire 40 and the elastic structural layer 32 slide relative to each other.

[0089] The lubricating layer 33 is a lubricating structure provided on the surface of the elastic structural layer 32. The central wire 40 contacts the lubricating layer 33, reducing friction when the central wire 40 moves or rotates within the first lumen 34. The lubricating layer 33 can be a lubricating coating or a lubricating pipe.

[0090] By providing a lubricating layer 33 on the inner side of the elastic structural layer 32, the lubricating layer 33 is in contact with the center wire 40. Compared with the contact between the center wire 40 and the elastic structural layer 32, the lubricating layer 33 can reduce the friction between the center wire 40 and the elastic structural layer 32 during relative sliding, so that the movement of the center wire 40 in the first cavity 34 is smoother, the adjustment of the center wire 40 is smoother, and it is not easy to interfere with or hinder the elastic structural layer 32.

[0091] According to some embodiments of the present application, the lubricating layer 33 is a polytetrafluoroethylene etched tube.

[0092] PTFE (Polytetrafluoroethylene) is a polymer compound made from tetrafluoroethylene. It is widely used due to its excellent chemical stability, corrosion resistance, sealing, high lubricity, electrical insulation and good anti-aging resistance.

[0093] When the lubricating layer 33 is a polytetrafluoroethylene etched tube, in order to facilitate the molding of the connecting tube 30 , the lubricating layer 33 can be provided in the first cavity 34 from the distal end of the connecting tube 30 to the second limiting portion 35 .

[0094] By using a polytetrafluoroethylene etched tube as the lubricating layer 33, and compared with applying a lubricating coating on the inner wall of the first lumen 34, the polytetrafluoroethylene etched tube has better durability. In this way, the outer wall of the central wire 40 contacts the inner wall of the polytetrafluoroethylene etched tube, and the inner wall of the polytetrafluoroethylene etched tube is relatively smooth. The central wire 40 can move more smoothly in the first lumen 34, and the central wire 40 can more flexibly select the target branch blood vessel.

[0095] According to some embodiments of the present application, a connector 21 is provided at the distal end of the electrode holder 20 , the connector 21 is embedded in the proximal end of the connecting tube 30 , and the connector 21 is hot-melt-connected to the polymer material layer 31 of the connecting tube 30 .

[0096] By providing a connector 21 at the distal end of the electrode holder 20, the connector 21 acts as an intermediate transition, allowing the mesh tube of the electrode holder 20 to be pre-connected to the connector 21 as a whole, and then hot-melt-connected to the polymer material layer 31 of the connecting tube 30, thereby reducing the difficulty of connecting the electrode holder 20 and the connecting tube 30.

[0097] According to some embodiments of the present application, the connecting member 21 is an annular metal sheet.

[0098] By using a metal sheet as the connector 21, the metal sheet can be easily welded to the mesh tube of the electrode holder 20, thereby improving the connection stability. Furthermore, the connector 21 adopts an annular structure, which facilitates sufficient welding area between the connector 21 and the elastic structure layer 32 in the subsequent circumferential direction, and thus facilitates ensuring the connection strength between the elastic structure layer 32 and the connector 21.

[0099] According to some embodiments of the present application, the elastic structural layer 32 is welded to the connecting member 21 .

[0100] When the polymer material layer 31 is formed on the elastic structure layer 32, since the elastic structure layer 32 is a mesh structure or a spring with gaps, part of the material of the polymer material layer 31 will enter the gaps of the elastic structure layer 32 after hot melting, so that the elastic structure layer 32 is embedded in the polymer material layer 31, and the elastic structure layer 32 and the polymer material layer 31 are integrated.

[0101] During assembly of the connecting tube 30, the elastic structural layer 32 can be welded to the connecting piece 21 to achieve a pre-connection between the elastic structural layer 32 and the connecting piece 21. This prevents the position of the elastic structural layer 32 from changing during the subsequent hot-melt process of the polymer material layer 31 of the connecting tube 30, thereby facilitating the molding accuracy of the connecting tube 30. Furthermore, welding the elastic structural layer 32 to the connecting piece 21 further enhances the installation stability of the elastic structural layer 32 within the connecting tube 30.

[0102] According to some embodiments of the present application, the inner diameter of the first lumen 34 is the same from the proximal end to the distal end, and the outer diameter of the connecting tube 30 gradually decreases.

[0103] The length of the connecting tube 30 can be 6 mm to 12 mm, and the specific size of the connecting tube 30 can be selected according to the actual situation.

[0104] From the proximal end to the distal end, the outer diameter of the connecting tube 30 is gradually reduced, and the connecting tube 30 is tapered. The distal end of the connecting tube 30 serves as a guide, which is more conducive to the connecting tube 30 entering the target branch blood vessel.

[0105] According to some embodiments of the present application, the radiofrequency ablation catheter 100 also includes a catheter 10, which is connected to one end of the electrode holder 20 away from the connecting tube 30. The catheter 10 has a second lumen 11 extending along its axial direction, and the central wire 40 is sequentially passed through the second lumen 11, the electrode holder 20 and the first lumen 34.

[0106] Catheter 10 is a tubular structure that houses and supports the various guidewires and center wire 40 of the radiofrequency ablation catheter 100. Catheter 10 can also deliver gas or liquid to a distal target blood vessel. Catheter 10 can be a multi-porous tube, with a portion of the lumen of catheter 100 used to accommodate radiofrequency wires, thermocouple wires, and other measurement wires, while a second lumen 11 is used to accommodate the center wire 40.

[0107] The catheter 10 can provide the function of accommodating various wires or central wire 40 of the radiofrequency ablation catheter 100. The second lumen 11 of the catheter 10 can be used for the central wire 40 to pass through. After the central wire 40 passes through the second lumen 11, the electrode bracket 20 and the first lumen 34 in sequence, the central wire 40 extends out of the connecting tube 30 to provide the function of branch superselection.

[0108] According to some embodiments of this application, please refer to Figure 7 、 Figure 8 and Figure 9 The radiofrequency ablation catheter 100 further includes an operating handle 50 , which is disposed on the proximal side of the catheter 10 and connected to the proximal end of the center wire 40 for controlling the movement of the center wire 40 relative to the catheter 10 .

[0109] The operating handle 50 refers to an operating component provided at the proximal end of the catheter 10 . The operating handle 50 controls the central wire 40 , controlling the rotation or axial movement of the central wire 40 .

[0110] The operating handle 50 includes a handle 51 and an operating member 52. The handle 51 is connected to the proximal end of the catheter 10. The handle 51 has a mounting cavity 511 inside. The proximal end of the center wire 40 extends into the mounting cavity 511 after passing through the catheter 10. The operating member 52 is connected to the proximal end of the center wire 40 via a fixing member 523. The operating member 52 is movably disposed in the mounting cavity 511 to control the center wire 40 and drive the center wire 40 to move axially or rotate.

[0111] Please refer to Figure 9 The operating member 52 may include a main body 521 and a rotating handle 522. The rotating handle 522 is fixedly connected to the main body 521. The main body 521 is movably arranged in the installation cavity 511. The main body 521 can move axially or rotate in the installation cavity 511. One side of the installation cavity 511 has an opening, and the opening allows the rotating handle 522 to extend out of the handle 51. The operator can directly act on the rotating handle 522 to drive the operating member 52 to move axially or rotate.

[0112] Through the setting of the operating handle 50, the operating handle 50 is connected to the proximal end of the center wire 40. The operating handle 50 plays the role of controlling the movement of the center wire 40. It can drive the center wire 40 to move axially or rotate relative to the catheter 10 according to needs, thereby realizing the distal rotation of the center wire 40 to explore the target branch blood vessel and realize the function of branch super selection.

[0113] An embodiment of the present application also provides a radiofrequency ablation device, which includes the radiofrequency ablation catheter 100 of any of the aforementioned embodiments and a control host, wherein the operating handle 50 is controlled by the operator, and can operate the central wire 40 and the electrode holder 20 to switch the working mode of the electrode holder 20 or use the central wire 40 for branch superselection, and the control host is used to control the radiofrequency ablation of the electrode holder 20, as well as perform temperature control, energy control, etc., to realize the radiofrequency ablation function.

[0114] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be substituted with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A radiofrequency ablation catheter, characterized in that: include: An electrode holder that can be radially contracted and expanded; a connecting tube, the proximal end of the connecting tube being connected to the distal end of the electrode holder, the connecting tube having a first lumen running through the proximal and distal ends thereof; a central wire movably passing through the electrode holder and the first lumen; In which, a first limiting portion is provided on the central wire, the first limiting portion is located in the first cavity, and a second limiting portion is correspondingly provided on the inner wall of the first cavity; when the first limiting portion and the second limiting portion are abutted, and the central wire moves from the distal end to the proximal end, the electrode bracket switches from a contracted state to an expanded state.

2. The radiofrequency ablation catheter according to claim 1, characterized in that A third limiting portion is provided on the central wire, and the third limiting portion and the first limiting portion are respectively located on opposite sides of the second limiting portion; when the third limiting portion abuts against the second limiting portion and the central wire moves from the proximal end to the distal end, the electrode holder can switch from the expanded state to the contracted state.

3. The radiofrequency ablation catheter according to claim 1, characterized in that The central wire includes a guide wire body and a soft guide wire arranged at the distal end of the guide wire body, and the first limiting portion is arranged on the guide wire body.

4. The radiofrequency ablation catheter according to claim 3, characterized in that: Along the radial direction of the soft guide wire, the soft guide wire includes an inner layer, a middle layer and an outer layer from the inside to the outside. The inner layer is a nickel-titanium grinding alloy wire, the middle layer is a high-density metal alloy spring, and the outer layer is a stainless steel spring.

5. The radiofrequency ablation catheter according to claim 1, characterized in that The connecting tube includes a polymer material layer and an elastic structure layer. The elastic structure layer is embedded inside the polymer material layer. The elastic structure layer encloses and defines the first cavity.

6. The radiofrequency ablation catheter according to claim 5, characterized in that The elastic structure layer is a metal woven mesh layer.

7. The radiofrequency ablation catheter according to claim 5, characterized in that: The elastic structural layer is a spring.

8. The radiofrequency ablation catheter according to claim 5, characterized in that: A lubricating layer is provided on the inner side of the elastic structural layer, and the lubricating layer is used to reduce the friction force when the central wire and the elastic structural layer slide relative to each other.

9. The radiofrequency ablation catheter according to claim 8, characterized in that: The lubricating layer is a polytetrafluoroethylene etching tube.

10. The radiofrequency ablation catheter according to claim 5, characterized in that: The distal end of the electrode bracket is provided with a connector, the connector is embedded in the proximal end of the connecting tube, and the connector is thermally melt-connected to the polymer material layer of the connecting tube.

11. The radiofrequency ablation catheter according to claim 10, characterized in that: The connecting piece is an annular metal sheet.

12. The radiofrequency ablation catheter according to claim 10, characterized in that: The elastic structural layer is welded to the connecting piece.

13. The radiofrequency ablation catheter according to claim 1, characterized in that From the proximal end to the distal end, the inner diameter of the first cavity is the same, and the outer diameter of the connecting tube gradually decreases.

14. The radiofrequency ablation catheter according to claim 1, characterized in that The radiofrequency ablation catheter further comprises: The catheter is connected to one end of the electrode holder away from the connecting tube. The catheter has a second lumen extending along its axial direction. The central wire is sequentially passed through the second lumen, the electrode holder and the first lumen.

15. The radiofrequency ablation catheter according to claim 14, characterized in that: The radiofrequency ablation catheter further comprises: An operating handle is provided at a proximal end of the catheter and is connected to the proximal end of the central wire for controlling the movement of the central wire relative to the catheter.

16. A radiofrequency ablation device, characterized in that: Comprising the radiofrequency ablation catheter according to any one of claims 1-15.

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