Radiofrequency ablation catheter for pulmonary nerve ablation

Abstract

The present application discloses a radiofrequency ablation catheter for performing pulmonary nerve ablation, which includes a core tube assembly and a plurality of electrodes mounted on the core tube assembly. The core tube assembly includes a core tube and an expansion portion connected to the distal end of the core tube; the expansion portion in the expanded state is a three-dimensional cage shape, and the expansion portion includes a plurality of solid elastic rods. One ends of the plurality of elastic rods converge and are connected, and the other ends are fixedly inserted into the distal portion of the core tube. Through the setting of the expansion portion, the technical solution disclosed in the present application enables the core tube assembly to perform stable, convenient, and accurate ablation operations on respiratory pipelines in different positions and forms, improving the efficiency of the operation and the treatment effect.

Description

Technical Field

[0001] This application relates to the field of interventional therapy, and particularly to a radiofrequency ablation catheter for pulmonary nerve ablation. Background Art

[0002] Chronic Obstructive Pulmonary Disease (COPD) is the most common disease in the respiratory system. In our country, according to the existing epidemiological investigation evidence, the prevalence of COPD in adults over 40 years old is about 10%.

[0003] Currently, the treatment of COPD mainly relies on drugs. Most commonly, anticholinergic drugs are used to specifically block the M receptors, causing relaxation of the airway smooth muscle, airway dilation, and reduction of mucus secretion, thereby alleviating airway obstruction and relieving the symptoms of COPD patients. Targeted Lung Denervation (TLD) ablation, on the other hand, targets the parasympathetic nerves and blocks their innervation, thereby achieving a permanent anticholinergic effect. The feasibility clinical study of this method was completed in 2015, and further clinical trials are currently underway.

[0004] With the continuous improvement of society's understanding of COPD and the continuous development of interventional techniques, the treatment of COPD through airway interventional techniques has been recognized by all sectors. As one of the treatment methods, TLD has advantages such as being more thorough and efficient compared to drug treatment. Therefore, we plan to develop a TLD ablation catheter and its supporting equipment to provide technical support for new methods of treating COPD.

[0005] As a new trend in the treatment of COPD in recent years, TLD ablation requires ablating the sympathetic nerves around the main bronchus to block their innervation, thereby achieving a permanent anticholinergic effect, reducing airway smooth muscle tension, and decreasing mucus secretion, thus improving the clinical symptoms of COPD.

[0006] During the ablation process, the inner wall of the main bronchus needs to be annularly ablated to form a closed ring of ablation points on the inner wall of the main bronchus in order to achieve effective blocking.

[0007] The inventors found that in related technologies, most of the annular catheters are electrophysiological mapping catheters, and most of the ablation catheters are monopolar ablation. Therefore, during the treatment process, multiple ablations are required to form a closed ring by ablation. The operation process is cumbersome and the treatment effect is not easy to control. If the ablation degree is insufficient, the ablated points are not easy to form a closed ring, and it is difficult to achieve effective blocking. If the ablation degree is excessive, the damage is too great, which is not conducive to the patient's recovery process.

[0008] At the same time, the internal diameter of the breathing tube will gradually become smaller as the intervention deepens, while the shape of the ablation electrode in the relevant technology is relatively fixed, and it has poor adaptability to target tissues with different arrangements. It is easy for the ablation position to be too high, resulting in excessive nerve inactivation, which has a greater impact on the patient. Summary of the invention

[0009] To address the above-mentioned problems, the present application discloses a radiofrequency ablation catheter for performing pulmonary nerve ablation, comprising a core tube assembly and a plurality of electrodes mounted on the core tube assembly. The core tube assembly comprises a core tube and an expansion portion connected to the distal end of the core tube. The expansion portion, in an expanded state, is in the shape of a three-dimensional mesh cage and comprises a plurality of solid elastic rods, one end of the plurality of elastic rods being converged and connected, and the other end being fixedly plugged into the distal end of the core tube.

[0010] Each electrode is fixed on a corresponding elastic rod, a cooling medium flow channel is opened inside each electrode, and an output port connected to the cooling medium flow channel is opened on the outer surface of each electrode;

[0011] A plurality of delivery pipes are passed through the core tube, one end of each delivery pipe is used to connect to the cooling medium delivery device, and the other end extends out of the core tube and extends along the corresponding elastic rod until it connects with the cooling medium flow channel of the electrode on the elastic rod.

[0012] Several optional methods are also provided below, but they are not intended to be additional limitations on the above-mentioned overall solution, but are merely further supplements or preferences. Under the premise that there are no technical or logical contradictions, each optional method can be combined with the above-mentioned overall solution separately, and multiple optional methods can also be combined.

[0013] Optionally, each elastic rod is pre-shaped into a radially contracted state, and a pull core is directly or indirectly connected to the distal end of each elastic rod, and the pull core extends toward the proximal end to pull the elastic rod to deform and enter an expanded state.

[0014] Optionally, each elastic rod is pre-shaped into a radially expanded state, and each elastic rod enters the expanded state in the following manner:

[0015] Relying on its own elasticity to enter an expanded state; or

[0016] The distal end of each elastic rod is directly or indirectly connected to a pulling core, and the pulling core extends toward the proximal end and is used to pull the elastic rod to deform and enter an expanded state.

[0017] Optionally, in the expanded state, in the axial direction of the core tube, both ends of the expansion portion are contracted, and the middle portion is expanded to form a working area; the electrode is mounted on the outer peripheral surface of the working area.

[0018] Optionally, the expansion portion includes a plurality of elastic rods, one ends of the plurality of elastic rods are converged and connected, and the other ends are fixedly inserted into the distal end of the core tube, and each electrode is fixed on a corresponding elastic rod.

[0019] Optionally, in a loading state opposite to the expanded state, the elastic rods are parallel to each other and contracted in the sheath; in the expanded state, the elastic rods are arc-shaped or wavy; and the electrodes are mounted at the top of the arc or the crest of the wave of the corresponding elastic rods.

[0020] Optionally, one end of the plurality of elastic rods is connected to a connector, and in an expanded state, the plurality of elastic rods are radially distributed with the connector as the center; the connector includes:

[0021] a central block, wherein the distal ends of the plurality of elastic rods are gathered together and abut against the outer periphery of the central block;

[0022] A fastening cap, wherein the fastening cap fastens and fixes the plurality of elastic rods and the central block;

[0023] The central block is provided with an adapting structure for connecting a pulling core, and the pulling core is used for pulling and changing the posture of the expansion part.

[0024] Optionally, the pull core is a solid structure;

[0025] Alternatively, the pulling core is a hollow structure, and an auxiliary cooling medium passage is formed inside the pulling core.

[0026] Optionally, a plurality of delivery tubes are passed through the core tube to form the delivery channels respectively, and each delivery channel supplies cooling medium to one of the electrodes; each delivery tube is a separately configured tube body or the core tube itself has a plurality of cavities, and each delivery tube is supplied by one of the cavities.

[0027] Optionally, each electrode is provided with a cooling medium flow channel and is connected to a corresponding delivery pipe, and the output port is provided on the outer surface of each electrode and is connected to the cooling medium flow channel inside the electrode; the distal end of the delivery pipe extends out of the core tube and extends along the corresponding elastic rod until it is connected to the electrode on the elastic rod.

[0028] Optionally, a sleeve is provided on the elastic rod, and the distal end of the delivery tube extends out of the core tube and then extends to the electrode within the sleeve; there are multiple output ports on each electrode, and the directions are different; the elastic rod is provided with a sleeve, and a first wire is connected to the electrode, and the first wire extends through the inside of the sleeve into the core tube and extends to the proximal end.

[0029] Optionally, a plurality of wetting holes connected to the output port are distributed on the electrode, and the cooling medium from the output port is distributed to the periphery of the electrode through the wetting holes.

[0030] Through the provision of the expansion part, the core tube assembly can achieve stable, convenient and accurate ablation operations on breathing tubes in different positions and forms, improving the efficiency of the operation and the treatment effect.

[0031] The specific beneficial effects will be explained in combination with specific embodiments in the specific implementation manners. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of a radiofrequency ablation catheter in an embodiment;

[0033] Figures 2a to 2b Schematic diagram of the expansion part in an embodiment;

[0034] Figure 3a and Figure 3b Schematic diagram of connector installation;

[0035] Figures 4a to 4f Schematic diagram of the cooling medium passage in the second embodiment;

[0036] Figure 5 Schematic diagram of the infiltration holes on the electrode.

[0037] The descriptions of the reference numerals in the drawings are as follows:

[0038] 1. Core tube assembly; 11. Expansion part; 111. Elastic rod; 1111. Cavity; 112. Connector; 1121. Central block; 1122. Fastening cap; 1123. Adaptation structure; 13. Delivery channel; 131. Output port; 132. Sleeve;

[0039] 2. Electrode; 21. Docking socket; 211. Ring-shaped protrusion; 22. Electrode card slot;

[0040] 4. Pull core;

[0041] 51. Infiltration holes. SPECIFIC IMPLEMENTATION MANNERS

[0042] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0043] It should be noted that when a component is referred to as being "connected" to another component, it can be directly connected to the other component or there may also be an intermediate component. When a component is considered to be "disposed on" another component, it can be directly disposed on the other component or there may be an intermediate component at the same time.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0045] Reference Figure 1 In the embodiment of, this embodiment discloses a radiofrequency ablation catheter for performing pulmonary nerve ablation, including a core tube assembly 1 and a plurality of electrodes 2 mounted on the core tube assembly 1.

[0046] The distal end of the core tube assembly 1 is an expansion part 11, and the plurality of electrodes 2 are arranged at intervals on the expansion part 11.

[0047] A delivery channel 13 is further provided inside the core tube assembly 1. One end of the delivery channel 13 is used to connect to a cooling medium delivery device, and the other end extends to the expansion part 11 and is independently configured with an output port 131 for each electrode 2.

[0048] The radiofrequency ablation catheter in this embodiment enters through the respiratory tract via a bronchoscope until the target point. The respiratory tract is quite different from other interventional paths. The diameter change of other interventional paths is less; while the diameter change of the respiratory tract is larger. Therefore, the radiofrequency ablation catheter realizes the treatment of different target positions through the core tube assembly 1 provided with the expansion part 11. The expansion part 11 can change its own volume, so as to move the electrodes 2 arranged on the expansion part 11 closer to the target position and match different diameters of the respiratory tract.

[0049] During the ablation process, it is necessary to deliver a cooling medium. The cooling medium can prevent the temperature of the target tissue from rising too high during the ablation process and affecting the treatment effect. In this embodiment, by independently designing the output ports 131 for the plurality of electrodes 2, independent control of the ablation parameters of the plurality of electrodes 2 is realized. The electrodes 2 being equipped with independent output ports 131 can provide a structural basis for independently controlling the ablation parameters of a single electrode 2, thereby obtaining a better ablation effect.

[0050] Whether the electrode 2 can approach the target point in a suitable posture depends on the deformation posture of the expansion part 11. Reference Figure 2a In the embodiment shown, the core tube assembly 1 includes a core tube and an expansion part 11;

[0051] The core tube has opposite distal and proximal ends, and the expansion part 11 is connected to the distal end of the core tube, and the expansion part 11 in the expanded state is a three-dimensional cage shape.

[0052] The expansion portion 11 has different technical requirements in the expanded state and the loaded state. When the expansion portion 11 is in the loaded state, it needs a smaller volume and higher flexibility to facilitate medical staff and other operators to perform interventional operations; when the expansion portion 11 is in the expanded state, it needs to have a larger deformation amount to ensure that it can fit the target position with different inner diameter sizes; when the expansion portion 11 is in the process of entering the expanded state from the loaded state, the deformation of the expansion portion 11 needs to be linearly controlled to facilitate the operation of medical staff and other operators. Taking into account the above requirements, the expansion portion 11 in this embodiment is preferably a three-dimensional cage shape. The cage-shaped expansion portion 11 can ensure a smaller volume and higher flexibility in the loaded state, a larger volume in the expanded state, and controllable deformation process. The three-dimensional mesh cage shape can be, for example, spherical, ellipsoidal, cylindrical, etc., but its geometric shape is not required to be very regular, only the general shape characteristics are there. In addition, the density of the mesh cage is not strictly limited. From another perspective, the aforementioned spherical, ellipsoidal, and cylindrical shapes can also be regarded as the shape of a rotating body formed by the expansion portion around its own axis (generally the axis of the core tube).

[0053] In one embodiment, the expansion portion 11 includes a plurality of solid elastic rods 111 , one end of the plurality of elastic rods 111 are converged and connected, and the other end is fixedly inserted into the distal end of the core tube.

[0054] The expansion portion 11 has elasticity due to the elastic rod 111 itself, but the direction of the elasticity can be optimized.

[0055] For example, in one embodiment, each elastic rod 111 is pre-shaped into a radially expanded state, and each elastic rod 111 enters the expanded state in the following manner:

[0056] Relying on its own elasticity to enter an expanded state; or

[0057] The distal end of each elastic rod 111 is directly or indirectly connected to a pull core 4 , and the pull core 4 extends toward the proximal end to pull the elastic rod 111 to deform and enter an expanded state.

[0058] The elastic force of the elastic rod 111 can drive the expansion portion 11 into the expanded state, that is, the expansion portion 11 is in the radially expanded state when no external force is applied. When loading, it can generally be combined with a sheath tube (not shown) that slides relative to the core tube to wrap and gather the expansion portion, thereby confining the expansion portion 11 in the loaded state. In this case, the pull core 4 can be omitted or combined with the pull core 4 to facilitate accurate control of the posture of the expansion portion.

[0059] In another embodiment, for example, each elastic rod 111 is pre-shaped into a radially contracted state, and the distal end of each elastic rod 111 is directly or indirectly connected to a pull core 4, which extends toward the proximal end to pull the elastic rod to deform into an expanded state.

[0060] When no external force is applied, the expansion part 11 is in a radially retracted loading state. At this time, the core puller 4 needs to be used in cooperation, and it is driven by the core puller 4 to enter the expansion state.

[0061] The elastic rods 111 in different predetermined shapes do not affect the setting of the electrodes, so they will not be separately distinguished hereinafter.

[0062] Regarding the specific setting of the electrode 2, refer to Figure 2b In the illustrated embodiment, the electrode 2 is provided on the outer peripheral surface of the expansion part 11.

[0063] The outer peripheral surface of the expansion part 11 is the part that is most likely to contact the inner wall of the respiratory tract. The electrode 2 provided on the outer periphery of the expansion part 11 can conveniently perform the ablation operation on the target tissue. More importantly, the expansion part 11 can be set in various shapes to adapt to the internal diameters and morphologies of different respiratory tracts. On this basis, electrodes can further be provided on the end surface at the distal end of the expansion part 11 to meet the ablation requirements of specific parts.

[0064] Regarding the specific setting of the expansion part 11, refer to Figures 3a to 3b In the illustrated embodiment, in the expansion state, in the axial direction of the core tube, both ends of the expansion part 11 are retracted, and the middle part bulges to form a working area; the electrode 2 is installed on the outer peripheral surface of the working area.

[0065] The expansion part 11 can control the degree of bulging of the middle part by the distance between both ends, so as to linearly control the expansion part, which is convenient for operators such as medical staff to accurately control the deformation process of the expansion part 11. The electrode 2 is provided on the outer peripheral surface of the working area. As the part with the largest volume of the expansion part 11 in the expansion state, the working area can better fit the inner wall of the respiratory tract and conveniently perform the ablation operation.

[0066] Refer to Figure 2a In the disclosed embodiment, the expansion part 11 includes a plurality of elastic rods 111. One ends of the plurality of elastic rods 111 are convergently connected, and the other ends are fixedly inserted into the distal part of the core tube. Each electrode 2 is fixed on a corresponding elastic rod 111.

[0067] The elastic rod 111 provides a driving force for the deformation of the expansion part 11. As a component directly driving the deformation of the expansion part 11, it has the maximum stress among all components. Therefore, setting the electrode 2 on the elastic rod 111 can ensure the position of the electrode 2 in the respiratory tract, improve the success rate of intervention, and improve the treatment efficiency. In other embodiments, multiple electrodes can also be arranged on the same elastic rod. Regarding the cross-sectional shape of the elastic rod 11, there is no strict limitation, and it can be circular, rectangular, elliptical, etc., while the elastic rod 11 itself is a solid structure. For a certain elastic rod 11, it can be a single rod body, or can adopt forms such as multi-strand twisting, or core wire combined with spiral wrapping, etc. The proximal ends of multiple elastic rods 111 converge and are fixedly inserted at the distal part of the core tube. The distal part of the core tube can use elastic tightening, welding and other methods to bind and fix the proximal ends of multiple elastic rods 111. In order to facilitate the threading of components such as guide wires, a central support member can be provided. The proximal ends of multiple elastic rods 111 converge and approach the outer periphery of the central support member, and the central support member is provided with avoidance holes for threading components such as guide wires.

[0068] During the intervention process and the ablation process, the shape of the expansion part 11 will change. In the loaded state, multiple elastic rods 111 are parallel and bundled; in the expanded state, each elastic rod is arc-shaped.

[0069] The elastic rods 111 that are parallel and bundled can provide a smaller volume, facilitating the implementation of the intervention process. At the same time, the parallel and bundled state reduces the stress of the deformation of the expansion part 11 during the insertion process, facilitating operation. The arc-shaped setting of the elastic rods can ensure that there will be no sharp appearance during the process of entering the human body, avoiding unnecessary injuries.

[0070] In the loaded state, each elastic rod basically extends along a straight line. After being bundled, it has a relatively small outer diameter as a whole to provide passability.

[0071] Regarding the specific setting position of the electrode 2, the electrode 2 is installed at the apex of the corresponding elastic rod 111.

[0072] The apex is the part where the elastic rod 111 has the largest deformation. Installing the electrode 2 at the apex can completely convert the deformation of the expansion part 11 into the change of the relative position of the electrode 2. Therefore, it can better adapt to the changing respiratory tract to meet complex treatment requirements. In the expanded state, each elastic rod is arc-shaped, and it can also be understood as a wave structure composed of multiple arc segments spliced together. There may be more than one apex, that is, peak position, such as 2 - 3. When multiple electrodes are arranged on the same elastic rod, each electrode is respectively arranged at the corresponding peak.

[0073] Regarding the spatial state setting of multiple elastic rods 111, refer to Figure 3aIn the disclosed embodiment, one end of the plurality of elastic rods 111 is connected to a connector 112 , and in the expanded state, the plurality of elastic rods 111 are radially distributed around the connector 112 .

[0074] The relative distance between the connector 112 and the distal end of the core tube can control the degree of deformation of the elastic member, thereby controlling the degree of deformation of the expansion portion 11. By connecting multiple elastic rods 111 to the connector 112, the connector 112 can achieve synchronous control of the multiple elastic rods 111, allowing medical personnel and other operators to accurately and conveniently control the state of the expansion portion 11 within the human body and accurately perform the ablation process. The radially distributed elastic rods 111 radiate the electrodes 2 from the core tube to the inner wall of the respiratory tract, thereby conveniently and accurately achieving annular ablation of the target point.

[0075] In the setting of connector 112, refer to Figure 3b In the disclosed embodiment, the connector 112 includes:

[0076] The distal ends of the plurality of elastic rods 111 gather together and abut against the outer periphery of the central block 1121;

[0077] The fastening cap 1122 fastens and fixes the plurality of elastic rods 111 together with the central block 1121 .

[0078] The provision of fastening caps 1122 facilitates the installation and positioning of elastic rods 111, reducing production precision requirements, improving production efficiency, and lowering production costs. Central block 1121, acting as a force-applying member to the elastic rods 111, applies the same force to each elastic rod 111 simultaneously and equally, facilitating control of the expansion portion 111's deformation by medical personnel and other operators.

[0079] Accordingly, reference Figure 3b In the disclosed embodiment, an adapting structure 1123 for connecting to the pulling core 4 is provided on the central block 1121 , and the pulling core 4 is used to pull and change the posture of the expansion portion 11 .

[0080] The pull core 4 is used to drive the relative distance between the central block 1121 and the distal end of the core tube, thereby applying a force to the elastic rod 111 to drive the elastic rod 111 to deform. The adapter structure is arranged on the proximal side of the central block 1121 and is fixed to the central block 1121 in an integral or separate manner. Specifically, the adapter structure can be a connecting hole, a hook, etc., and the distal end of the pull core 4 can be inserted and welded into the connecting hole, or tied and fixed to the hook.

[0081] In different embodiments, the pull core 4 is a solid structure or a hollow structure.

[0082] When in a hollow structure, an auxiliary cooling medium passage is formed inside the core pull 4, and a cooling medium (such as normal saline) can be introduced to form auxiliary cooling.

[0083] In a preferred embodiment, the central block 1121 can be provided with an opening connected to the auxiliary cooling medium passage, and the cooling medium can be directly output. A valve body structure can be arranged inside the central block 1121 to control the on-off state of the auxiliary cooling medium passage.

[0084] The auxiliary cooling medium passage inside the core pull 4 also forms a loop to implement temperature reduction in the way of circulating the cooling medium, and this loop can pass through or not pass through the central block 1121.

[0085] In a specific setting, referring to Figure 4a In the disclosed embodiment, the number of the plurality of elastic rods 111 is 4.

[0086] The more the number of the elastic rods 111, the more positions where the electrodes 2 can be arranged correspondingly, so that the annular ablation of the target point can be realized more conveniently. However, the increase in the number of the elastic rods 111 will also increase the difficulty of bending the distal end of the core tube during the intervention process. Therefore, it is preferably 3 or 4.

[0087] The elastic rod 111 being a solid rod can reduce the volume as much as possible under the same mechanical parameters, thereby providing a better intervention effect.

[0088] In one embodiment, the plurality of elastic rods 111 are made of nitinol alloy, and the elastic rods 111 are insulated from the electrodes 2 by plating an insulating layer or covering an insulating tube.

[0089] Nitinol alloy is convenient for preforming and can be conveniently expanded to a preset shape in the human body, which is convenient for operators such as medical staff to operate; the shape of the respiratory tract is variable and complex. In addition to the electrodes 2 contacting the inner wall of the breathing tube, the elastic rods 111 may also contact the inner wall of the respiratory tract. Therefore, insulation needs to be provided between the elastic rods 111 and the electrodes 2 to avoid harm to normal tissues.

[0090] Referring to Figure 4d In the disclosed embodiment, the electrodes 2 are provided with electrode slots 22 and are fixed on the corresponding elastic rods 111 through these slots.

[0091] During the ablation process, the electrode 2 may become adhered to the target tissue. When the core tube is moved, a certain connection strength between the electrode 2 and the elastic rod 111 must be maintained. Therefore, the electrode retaining groove 22 is a preferred design, which can improve the force-bearing performance of the electrode 2 in all directions through structural means. The electrode retaining groove 22 also prevents the electrode 2 from rotating around the elastic rod 111, avoiding unnecessary misalignment. To ensure this anti-rotation and misalignment effect, in a preferred embodiment, at least a portion of the mating portion between the electrode retaining groove 22 and the elastic rod 111 is flat. In addition, positioning protrusions and other structures can be provided along the length of the elastic rod 111 to limit the slippage of the electrode 2.

[0092] In addition to being used to transport the electrodes 2, the core tube is also used to transport cooling medium to the vicinity of the target. The cooling medium can cool the tissue near the target when the electrodes 2 are operating, thereby improving the ablation effect. In one embodiment, multiple delivery tubes are provided within the core tube to form delivery channels 13, each of which supplies cooling medium to one of the electrodes 2. Multiple delivery pipelines can ensure the flow of cooling medium when multiple electrodes 2 are performing ablation operations, thereby ensuring the ablation effect. In one embodiment, the flow rate of each delivery tube is independently controlled.

[0093] In some use cases, the ablation parameters of each electrode 2 may need to be independently controlled, resulting in inconsistent cooling medium requirements. This embodiment achieves precise control of the cooling medium by independently controlling the flow rate of the delivery tube. This improves the control accuracy and adaptability of the radiofrequency ablation catheter used for pulmonary nerve ablation, achieving excellent ablation results for targets in different locations and situations.

[0094] The independent control method can adopt existing technology, for example, a delivery pump and a corresponding control circuit are separately configured for each delivery channel.

[0095] In one embodiment, each delivery tube is a separately configured tube body or core tube with multiple lumens, and each delivery tube is provided by one of the lumens.

[0096] Each delivery tube configuration has its own advantages. For example, a standalone design offers greater flow, making it suitable for applications with larger pipe diameters and high cooling medium flow requirements. Another example is a core tube with multiple lumens, which creates a more uniform external shape and facilitates interventional procedures within narrow airways. The specific choice can be combined with other design options based on the specific application scenario.

[0097] When multiple cavities are used, they can be integrally formed when processing the core tube, for example, by extrusion molding using a die with a corresponding structure.

[0098] The cooling medium needs to diffuse to the part where the ablation is achieved by the electrode 2 to play its role. In the cooperation between the cooling medium and the electrode 2, referring to Figures 4a to 4c In the illustrated embodiment, cooling medium flow channels are respectively formed on each electrode 2 and are docked with a corresponding delivery tube. The outlet 131 is formed on the outer surface of each electrode 2 and is communicated with the cooling medium flow channel inside the corresponding electrode 2.

[0099] The cooling medium directly diffuses from the electrode 2 to the target position, which can ensure the synchronization between the cooling medium and the ablation position, and improve the effect of the cooling medium. At the same time, when the cooling medium flows through the electrode 2, the temperature difference between the tissue near the target and the electrode 2 can be reduced, which is convenient for the implementation of ablation parameter control means such as temperature control. In actual application scenarios, the cooling medium is generally conductive physiological saline, and the physiological saline diffusing from the electrode 2 can also improve the ablation effect and optimize the ablation working environment.

[0100] In specific settings, referring to Figure 4a In the disclosed embodiment, the distal portion of the delivery tube extends out of the core tube and then extends along the corresponding elastic rod 111 until it is docked with the electrode 2 on the elastic rod 111.

[0101] The delivery tube is arranged along the elastic rod 111, which can better adapt to the deformation of the expansion part 11. At the same time, the elastic rod 111 is a force-applying member for driving the deformation of the expansion part 11, which can prevent the delivery tube from undergoing occlusive deformation under external force, ensuring that the cooling medium can be stably delivered to the electrode 2.

[0102] Referring to Figures 4d to 4f to the illustrated embodiment, where Figure 4e is Figure 4d a side sectional view, Figure 4f is Figure 4d a top sectional view. The electrode 2 is provided with a docking socket 21 connected to the delivery tube. The docking socket 21 itself is tubular and can be an integral structure or a split-fixed structure with the electrode. The docking socket 21 is provided with an annular protrusion 211 to prevent the delivery tube from falling out. A structure similar to a tee is formed inside the electrode 2 to diffuse the cooling medium from the docking socket 21 to the ablation site through the outlet 131 on the electrode 2.

[0103] In another embodiment, in order to facilitate the docking between each electrode 2 and the delivery tube, the electrode 2 can be provided with a slot, which is communicated with the cooling medium flow channel inside the motor. The end of the delivery tube is fixed in the slot. In one embodiment, a sleeve 132 is provided on the elastic rod 111, and the distal portion of the delivery tube extends out of the core tube and then extends in the sleeve 132 to the electrode 2.

[0104] To prevent the tissue in the respiratory tract from affecting the delivery tube, the sleeve 132 can form a relatively enclosed environment. At the same time, the sleeve 132 can also act as an insulating layer to prevent the radiofrequency energy on the electrode 2 from being transmitted to the normal tissue through the elastic rod 111.

[0105] Reference Figure 4d In the disclosed embodiments, there are multiple output ports 131 on each electrode 2, and they are oriented in different directions.

[0106] When the electrode 2 ablates the tissue at the target point, it will spread in multiple directions. Therefore, the cooling medium also needs to spread in multiple directions to ensure the orderly progress of ablation. Therefore, in this embodiment, by setting the output ports 131 in different orientations, the cooling medium can spread in different directions, ensuring the coverage area of the cooling medium. When there are multiple output ports 131 on the electrode 2, the cooling medium flow channel inside the electrode 2 can adopt a branch structure. One end of each branch is linked to the delivery tube, and the other end is respectively connected to the corresponding output port 131.

[0107] During the ablation process of the electrode 2, it is necessary to deliver radiofrequency energy proximally. Wires need to be arranged on the core tube. In the embodiment, a sleeve 132 is provided on the elastic rod 111, a first wire is connected to the electrode 2, and the first wire extends inside the sleeve 132 to the inside of the core tube and then extends proximally.

[0108] The wire is protected by the sleeve 132, thus avoiding the friction with the respiratory tract from affecting the stability of the wire, which is very important in the interventional field and often directly affects the treatment effect and the surgical efficiency. The sleeve 132 can preferably be a PTFE shrink tube in terms of material.

[0109] During the ablation operation, the ablation state and degree of the electrode 2 need to be controlled by multiple parameters. In one embodiment, the radiofrequency ablation catheter further includes multiple temperature sensors, and each temperature sensor is attached to or embedded in the corresponding electrode 2.

[0110] Temperature is a parameter that is relatively easy to observe during the ablation operation and is directly related to the ablation process. Through the temperature sensor, the ablation degree and process can be directly controlled. The design of attaching or embedding the temperature sensor to the electrode 2 can more accurately detect the ablation state of the electrode 2. At the same time, the separate setting of the temperature sensor for each electrode 2 provides a structural basis for independently controlling the ablation parameters of multiple electrodes 2.

[0111] In one embodiment, a sleeve 132 is provided on each elastic rod 111, a second wire is connected to each sensor, and each second wire extends inside the sleeve 132 to the inside of the core tube and then extends proximally.

[0112] The second wire is protected by the sleeve 132, thus avoiding the friction with the respiratory tract from affecting the stability of the second wire, ensuring the stability of the temperature sensor reading, and thereby improving the accuracy of ablation control. The sleeve 132 can preferably be a PTFE shrink tube in terms of material. Combining the foregoing embodiments, the first wire and the second wire can be wrapped in the same sleeve 132.

[0113] When the cooling medium diffuses to the target point, in addition to natural diffusion, infiltration holes 51 can be designed to improve the diffusion effect. Refer to Figure 5 In the disclosed embodiments, a plurality of infiltration holes 51 communicating with the output port 131 are distributed on the electrode 2, and the cooling medium from the output port 131 is distributed to the periphery of the electrode 2 via the infiltration holes 51.

[0114] The infiltration holes 51 can better diffuse the cooling medium to the target point, especially between the contact surface of the electrode 2 and the target point, thereby optimizing the ablation effect and facilitating the control of the ablation process. A number of fine infiltration holes 51 are uniformly distributed on the electrode 2. The cooling medium enters the internal channel of the electrode 2 from the delivery tube and flows out from the infiltration holes 51, forming a thin film of cooling medium in the form of a water film on the outer surface of the electrode 2, so that the electrode surface is wetted by the cooling medium (in this embodiment, the cooling medium is normal saline), further avoiding the ablation tissue from scabbing and reducing the loop impedance. Maintaining impedance balance enables the ablation process to continue until the target ablation volume is reached.

[0115] The aperture and density distribution of the infiltration holes 51 can be set according to the flow rate requirement of the heat exchange medium, and an attempt is made to ensure the formation of a uniform protective film on the outer periphery of the electrode. For example, all the infiltration holes 51 have the same aperture, or are correspondingly set according to the balance of the heat exchange medium flow rate.

[0116] That is, the aperture of the infiltration holes 51 in different regions can be changed to meet the requirement of balanced flow rate. Similarly, the distribution density of all the infiltration holes 51 is the same at different parts of the electrode 2, or is correspondingly set according to the balance of the heat exchange medium flow rate.

[0117] When correspondingly setting according to the balance of the heat exchange medium flow rate, the layout mode of the outlet of the heat exchange medium flow channel is mainly considered. For example, the aperture of the infiltration holes 51 increases with the increase of the distance from the outflow hole.

[0118] Similarly, for example, the distribution density of the infiltration holes 51 increases with the increase of the distance from the outflow hole.

[0119] When processing the infiltration holes 51, they can be arranged according to the expected layout. For example, in one embodiment, multiple groups of infiltration holes 51 are distributed in the circumferential direction of the electrode 2.

[0120] In one embodiment, the expansion part 11 includes multiple elastic rods 111. One ends of the multiple elastic rods 111 converge and are connected, and the other ends are fixedly inserted into the distal part of the core tube. Each electrode 2 is fixed on a corresponding elastic rod 111.

[0121] As the main structural member of the expansion part 11, the elastic rod 111 can ensure the installation effect of the electrode 2 when the electrode 2 is wrapped around the elastic rod 111, avoiding the installation failure due to friction with the respiratory tissue during the intervention process, and also ensuring that the cooling medium can be stably delivered to the target point.

[0122] Regarding the specific structure of the electrode 2, refer to Figure 5 In the disclosed embodiment, the electrode 2 is a closed structure in the circumferential direction of the elastic rod 111 where it is located.

[0123] Correspondingly, in one embodiment, the electrode 2 is a non-closed structure in the circumferential direction of the elastic rod 111 where it is located. The closed-structure electrode 2 can ensure a good connection relationship with the elastic rod 111 and can also provide sufficient strength in some treatment scenarios where force contact with the respiratory tissue is required. Correspondingly, the non-closed-structure electrode 2 is convenient for installation and assembly, and through corresponding structural optimization, the force-bearing strength of the closed structure can also be achieved. Therefore, the specific installation method of the electrode 2 can be selected according to the usage scenario and design indicators as needed.

[0124] From the perspective of the cooling medium passage, in one embodiment, a distribution groove (not shown in the figure) is provided on the outer wall of the electrode 2, and the cooling medium from the output port 131 is supplied to the infiltration holes 51 on the outer periphery of the corresponding electrode 2 via the distribution groove.

[0125] In terms of the specific usage method, the radiofrequency ablation catheter for pulmonary nerve ablation disclosed in this application establishes an interventional access through a bronchoscope. After the bronchoscope reaches the lesion (i.e., the target) location, the sheath tube with the core tube assembly 1 is inserted into the bronchoscope. The adjustable knob is twisted to relax the pull core 4, enabling the expansion part 11 to contract and close together into the loading state. The core tube assembly 1 is pushed, passing through the bronchoscope from the sheath tube. After the expansion part 11 passes through the bronchoscope, the expansion part 11 is observed through the bronchoscope, and the handle at the proximal end is rotated to adjust the position of the electrode 2. After the adjustment is completed, the adjustable knob is rotated to pull the pull core 4, driving the expansion part 11 into the expanded state and expanding it to make the electrode 2 fit well against the inner wall of the bronchus. Then, a cooling medium is introduced. In this embodiment, cold saline is used. Then, the radiofrequency instrument is turned on, and multiple electrodes 2 perform ablation simultaneously (the flow rate of the cold saline pump should be adjusted according to the ablation temperature of the radiofrequency instrument. If the temperature is higher than 60°C, the saline flow rate should be increased; if the temperature does not exceed 60°C, the flow rate remains unchanged, and the saline flow rate is adjusted within the range of 3 - 15 ml / min). The ablation power range is 3 - 10 W, and the ablation time is 60 s - 120 s. During ablation, the bronchoscope cooperates to extract the excess saline in the cavity. After ablation is completed, the pull core 4 is relaxed through the adjustable knob, and the expansion part 11 naturally enters the loading state relying on the self-elastic force of the elastic rod 111. The ablation position is adjusted to perform the next round of ablation, and finally, a closed loop is formed at the ablation points on the inner wall of the main bronchus. At this time, if the ablation points are observed through the bronchoscope and there are unclosed situations, the expansion part 11 is adjusted so that one of the electrodes 2 is at the notch position for monopolar ablation until a closed loop is formed at the ablation points.

[0126] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity in description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as within the scope described in this specification. When the technical features in different embodiments are shown in the same drawing, it can be regarded that the drawing also discloses the combination examples of the respective embodiments involved.

[0127] The above-described embodiments only represent several implementation manners of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can still be made, and these all belong to the protection scope of this application. Therefore, the protection scope of this application patent should be subject to the appended claims.

Claims

1. A radiofrequency ablation catheter for performing pulmonary nerve ablation, comprising a core tube assembly and a plurality of electrodes mounted on the core tube assembly, characterized in that, The core tube assembly includes a core tube and an expansion portion connected to the distal end of the core tube; the expansion portion in the expanded state is in the shape of a three-dimensional mesh cage, and the expansion portion includes a plurality of solid elastic rods, one end of the plurality of elastic rods is converged and connected, and the other end is fixedly inserted into the distal end of the core tube; the distal end of each elastic rod is directly or indirectly connected to a pull core, and the pull core extends toward the proximal end to pull the elastic rod to deform and enter the expanded state; Each electrode is fixed on a corresponding elastic rod, a cooling medium flow channel is opened inside each electrode, and an output port connected to the cooling medium flow channel is opened on the outer surface of each electrode; A plurality of delivery pipes are passed through the core tube, one end of each delivery pipe is used to connect to the cooling medium delivery device, and the other end extends out of the core tube and extends along the corresponding elastic rod until it is connected to the cooling medium flow channel of the electrode on the elastic rod. The pulling core is a hollow structure, and an auxiliary cooling medium passage is formed inside the pulling core to circulate the cooling medium.

2. The radiofrequency ablation catheter for performing pulmonary nerve ablation according to claim 1, characterized in that, Each elastic rod is pre-shaped into a radially contracted state, and a pull core is directly or indirectly connected to the distal end of each elastic rod. The pull core extends toward the proximal end and is used to pull the elastic rod to deform and enter an expanded state.

3. The radiofrequency ablation catheter for performing pulmonary nerve ablation according to any one of claims 1 to 2, characterized in that, In the expanded state, in the axial direction of the core tube, the two ends of the expansion portion are contracted, and the middle portion is expanded to form a working area; the electrode is mounted on the outer peripheral surface of the working area.

4. The radiofrequency ablation catheter for performing pulmonary nerve ablation according to claim 3, characterized in that, In the loading state opposite to the expansion state, the elastic rods are parallel to each other and gathered in the sheath tube; in the expansion state, the elastic rods are arc-shaped or wavy; the electrodes are installed at the top of the arc or the crest of the wave of the corresponding elastic rods.

5. The radiofrequency ablation catheter for performing pulmonary nerve ablation according to claim 1, wherein One end of the plurality of elastic rods is connected to a connector, and in the expanded state, the plurality of elastic rods are radially distributed with the connector as the center; the connector includes: a central block, wherein the distal ends of the plurality of elastic rods are gathered together and abut against the outer periphery of the central block; A fastening cap, wherein the fastening cap fastens and fixes the plurality of elastic rods and the central block; The central block is provided with an adapting structure for connecting a pulling core, and the pulling core is used for pulling and changing the posture of the expansion part.

6. The radiofrequency ablation catheter for performing pulmonary nerve ablation according to claim 5, characterized in that, The central block has an opening connected to the auxiliary cooling medium passage, and a valve body structure is provided in the central block for controlling the on-off state of the auxiliary cooling medium passage.

7. The radiofrequency ablation catheter for performing pulmonary nerve ablation according to claim 5, characterized in that, The auxiliary cooling medium passage inside the pulling core also forms a loop to implement temperature reduction in a manner of circulating the cooling medium, and the loop may pass through or not pass through the central block.

8. The radiofrequency ablation catheter for performing pulmonary nerve ablation according to claim 1, wherein The core tube is provided with a plurality of delivery tubes for forming delivery channels respectively, and each delivery channel supplies cooling medium to one of the electrodes; each delivery tube is a separately configured tube body or the core tube itself has a plurality of lumens, and each delivery tube is supplied by one of the lumens; A cooling medium flow channel is provided on each electrode and is connected to a corresponding delivery pipe. The output port is provided on the outer surface of each electrode and is connected to the cooling medium flow channel inside the electrode. The distal end of the delivery pipe extends out of the core pipe and then extends along the corresponding elastic rod until it is connected to the electrode on the elastic rod.

9. The radiofrequency ablation catheter for performing pulmonary nerve ablation according to claim 8, wherein, The elastic rod is provided with a sleeve, and the distal end of the delivery tube extends out of the core tube and then extends to the electrode in the sleeve; each electrode has multiple output ports, and the output ports are oriented in different directions; A sleeve is provided on the elastic rod, a first wire is connected to the electrode, and the first wire extends through the interior of the sleeve into the core tube and extends proximally.

10. The radiofrequency ablation catheter for implementing pulmonary nerve ablation according to claim 1, characterized in that, A plurality of infiltration holes communicating with the output port are distributed on the electrode, and the cooling medium from the output port is distributed to the periphery of the electrode through the infiltration holes.

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