Mesh cage type radiofrequency ablation catheter

Abstract

The present application discloses a mesh-cage type radiofrequency ablation catheter, comprising a core tube assembly and a plurality of electrodes mounted on the core tube assembly, characterized in that the core tube assembly comprises a core tube and an expansion portion connected to the distal end of the core tube; the expansion portion has a radially contracted loading state and a radially expanded expansion state, and the expansion portion in the expanded state is in a three-dimensional mesh cage shape, and the expansion portion comprises a plurality of hollow elastic rods, one end of the plurality of elastic rods converges and is connected, and the other end is fixedly plugged into the distal end of the core tube. The technical solution disclosed in the present application realizes that the core tube assembly can achieve stable, convenient, and accurate ablation operations for respiratory ducts of different positions and shapes through the setting of the expansion portion, thereby improving the efficiency of the operation and the effect of the treatment.

Description

Technical Field

[0001] This application relates to the field of interventional therapy, and particularly to a cage-type radiofrequency ablation catheter. 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 rate 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 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 technologies, the treatment of COPD through airway interventional technologies 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 TLD ablation catheters and their 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 ablation of the sympathetic nerves around the main bronchus to block their innervation, thereby achieving a permanent anticholinergic effect, reducing the airway smooth muscle tension, and decreasing mucus secretion, thus improving the clinical symptoms of COPD.

[0006] During the ablation process, it is necessary to perform circumferential ablation on the inner wall of the main bronchus to form a closed loop 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 circumferential 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 loop 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 loop, 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 related 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] In order to solve the above problems, the present application discloses a mesh-cage type radiofrequency ablation catheter, comprising a core tube assembly and a plurality of electrodes mounted on the core tube assembly, wherein 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 a three-dimensional mesh-cage shape, and the expansion portion comprises a plurality of hollow elastic rods, one end of the plurality of elastic rods are converged and connected, and the other end is fixedly plugged into the distal end of the core tube, and each electrode is fixed on a corresponding elastic rod;

[0010] A plurality of delivery pipes are provided in the core tube, one end of each delivery pipe is used to connect to a cooling medium delivery device, and the other end is connected to a corresponding elastic rod;

[0011] Each elastic rod is also provided with an output port connected with its own inner cavity, and the position of the output port is adjacent to the electrode on the same 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 a state of expansion; 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 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, 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.

[0018] Optionally, in a loading state relative to the expanded state, the elastic rods are mutually parallel and converged in the sheath; in the expanded state, the elastic rods are arc-shaped or wavy; and the electrodes are installed at the top of the arc or the crest of the wave of the corresponding elastic rods.

[0019] 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 comprises:

[0020] A central block, wherein the distal ends of the plurality of elastic rods gather together and abut against the outer periphery of the central block;

[0021] A fastening cap, wherein the fastening cap fastens and fixes the plurality of elastic rods together with the central block;

[0022] The central block is provided with an adapting structure for connecting a pull core, and the pull core is used for pulling and changing the posture of the expansion part.

[0023] Optionally, the pull core is a solid structure;

[0024] Or the pull core is a hollow structure, and an auxiliary cooling medium passage is formed inside the pull core, and the auxiliary cooling medium passage is connected or not connected with the inner cavity of the elastic rod itself.

[0025] Optionally, a plurality of delivery pipes are provided in the core tube to form the delivery channels respectively, and each delivery channel supplies cooling medium to one of the electrodes; and the flow rate of each delivery pipe is independently controlled.

[0026] Optionally, a plurality of delivery tubes are passed through the core tube to form the delivery channels respectively, the plurality of elastic rods are hollow rods and the proximal ends of the elastic rods are connected to a corresponding delivery tube, and the output port is opened on the elastic rod and connected to the cavity of the elastic rod.

[0027] Optionally, the output port and the electrode on the same elastic rod are adjacent to each other, and the output port is located at the distal end side of the electrode.

[0028] Optionally, there are multiple output ports on the same elastic rod, and they are arranged along the length direction of the elastic rod.

[0029] Optionally, a sleeve is provided on the elastic rod, 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; the radiofrequency ablation catheter also includes a plurality of temperature sensors, each temperature sensor is attached to or embedded in a corresponding electrode; each elastic rod is provided with a sleeve, each sensor is connected to a second wire, and each second wire extends through the inside of the sleeve into the core tube and then extends to the proximal end.

[0030] Optionally, 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.

[0031] Through the cage-like arrangement of the expansion part in this application, 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 therapeutic effect.

[0032] The specific beneficial effects will be explained in combination with specific embodiments in the specific implementation manners. Description of the Drawings

[0033] Figure 1 Schematic diagram of a radiofrequency ablation catheter in an embodiment;

[0034] Figures 2a to 2e Schematic diagram of the expansion part in an embodiment;

[0035] Figure 3a and Figure 3b Schematic diagram of the connector installation;

[0036] Figure 4 is Figure 2d Partial enlarged schematic diagram of;

[0037] Figures 5a to 5c Schematic diagram of the cooling medium passage in the first embodiment;

[0038] Figure 6 Schematic diagram of the infiltration holes on the electrode.

[0039] The descriptions of the reference numerals in the drawings are as follows:

[0040] 1. Core tube assembly; 11. Expansion part; 111. Elastic rod; 1111. Cavity; 1112. Sleeve; 112. Connector; 1121. Central block; 1122. Fastening cap; 1123. Adaptation structure; 13. Delivery channel; 131. Output port;

[0041] 2. Electrode; 4. Pull core; 51. Infiltration hole. Specific Implementation Manner

[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 may be directly connected to the other component or there may be a central component. When a component is referred to as being "disposed on" another component, it may be directly disposed on the other component or there may be a central component at the same time.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments 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] The present application discloses a cage-type radiofrequency ablation catheter, comprising a core tube assembly and a plurality of electrodes installed on the core tube assembly, wherein the core tube assembly comprises a core tube and an expansion portion connected to the distal end of the core tube;

[0046] The expansion part in the expanded state is in the shape of a three-dimensional mesh cage, and the expansion part includes a plurality of hollow elastic rods, one end of the plurality of elastic rods are converged and connected, and the other end is fixedly inserted in the distal end of the core tube, and each electrode is fixed on a corresponding elastic rod;

[0047] A plurality of delivery pipes are provided in the core tube, one end of each delivery pipe is used to connect to a cooling medium delivery device, and the other end is connected to a corresponding elastic rod;

[0048] Each elastic rod is also provided with an output port connected with its own inner cavity, and the position of the output port is adjacent to the electrode on the same elastic rod.

[0049] Whether the electrode 2 can approach the target point in a suitable posture depends on the deformation posture of the expansion portion 11. Figure 2a In the illustrated embodiment, the core tube assembly 1 comprises a core tube and an expansion portion 11;

[0050] The core tube has a distal end and a proximal end opposite to each other. The expansion portion 11 is connected to the distal end of the core tube, and the expansion portion 11 in an expanded state is in a three-dimensional cage shape.

[0051] The expansion part 11 has different technical requirements in the expanded state and the loaded state. When the expansion part 11 is in the loaded state, it needs a smaller volume and higher flexibility to facilitate interventional operations by medical staff and other operators; when the expansion part 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 diameters; when the expansion part 11 enters the expanded state from the loaded state, the deformation of the expansion part 11 needs to be linearly controlled to facilitate the operation of medical staff and other operators. Taking the above requirements into account, the expansion part 11 in this embodiment is preferably a three-dimensional cage-shaped expansion part 11. The cage-shaped expansion part 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).

[0052] 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.

[0053] The expansion portion 11 has elasticity due to the elastic rod 111 itself, but the direction of the elasticity can be optimized.

[0054] 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:

[0055] Relying on its own elasticity to enter a state of expansion; or

[0056] 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.

[0057] The elastic force of the elastic rod 111 can drive the expansion part 11 into the expansion state, that is, the expansion part 11 is in the expansion state of radial expansion when no external force is applied. When loading, it can generally cooperate with the sheath tube (not shown) that slides relatively with the core tube to wrap and gather the expansion part, and limit the expansion part 11 to the loading state. At this time, the pull core 4 can be omitted, or the pull core 4 can be cooperated to accurately adjust the posture of the expansion part.

[0058] 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.

[0059] When no external force is applied, the expansion portion 11 is in a radially contracted loading state. At this time, the pull core 4 needs to be used in conjunction with the pull core 4 to drive the expansion portion 11 into the expansion state.

[0060] The different states of the elastic rod 111 in the predetermined shape do not affect the setting of the electrode, so they are not distinguished separately below. Figure 2b In the illustrated embodiment, the electrode 2 is disposed on the outer circumferential surface of the expansion portion 11 .

[0061] The outer peripheral surface of the expansion portion 11 is the part that is most likely to contact the inner wall of the respiratory tract. The electrodes 2 arranged on the outer periphery of the expansion portion 11 can conveniently perform ablation operations on the target tissue. More importantly, the expansion portion 11 can be set in a variety of shapes to adapt to different internal diameters and shapes of the respiratory tract. On this basis, electrodes can be further set on the end surface of the distal end of the expansion portion 11 to meet the ablation requirements of specific parts.

[0062] Regarding the specific configuration of the expansion portion 11, refer to Figures 2a to 2b In the illustrated embodiment, in the expanded state, in the axial direction of the core tube, the two ends of the expansion portion 11 are closed, and the middle portion is expanded to form a working area; the electrode 2 is mounted on the outer peripheral surface of the working area.

[0063] The expansion part 11 can control the expansion degree of the middle part by the distance between the two ends, so as to linearly control the expansion part, which is convenient for medical personnel and other operators to accurately control the deformation process of the expansion part 11. The electrode 2 is arranged on the outer peripheral surface of the working area. The working area is the part with the largest volume of the expansion part 11 in the expanded state, which can better fit the inner wall of the respiratory tract and facilitate the ablation operation.

[0064] refer to Figure 2a In the disclosed embodiment, the expansion portion 11 includes a plurality of elastic rods 111 , one end of the plurality of elastic rods 111 are converged and connected, and the other end is fixedly inserted in the distal end of the core tube, and each electrode 2 is fixed on a corresponding elastic rod 111 .

[0065] 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 enhance 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, oval, etc. The elastic rod 11 itself has a hollow structure for laying lines or transporting materials inside. 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 coating, etc. The proximal ends of multiple elastic rods 111 converge and are fixedly inserted into the distal part of the core tube. The distal part of the core tube can use methods such as elastic tightening and welding 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.

[0066] During the intervention process and the ablation process, the shape of the expansion part 11 will change. Refer to Figure 2d In the disclosed embodiments, in the loaded state, multiple elastic rods 111 are parallel and bundled; in the expanded state, each elastic rod is arc-shaped.

[0067] The parallel and bundled elastic rods 111 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 rod can ensure that there will be no sharp appearance during the process of entering the human body, avoiding unnecessary injuries.

[0068] 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.

[0069] Regarding the specific setting position of the electrode 2, refer to Figure 2e In the disclosed embodiments, the electrode 2 is installed at the apex of the corresponding elastic rod 111.

[0070] The apex is the part where the elastic rod 111 has the largest amount of 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 can also be understood as a wave structure composed of multiple arc segments spliced together. There may be more than one apex, that is, the peak part, for example, 2 to 3 places. When multiple electrodes are arranged on the same elastic rod, each electrode is respectively arranged at the corresponding peak.

[0071] Regarding the spatial state setting of multiple elastic rods 111, refer toFigure 3a In the disclosed embodiment, one end of a 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 as the center.

[0072] The relative distance between the connector 112 and the distal end of the core tube can control the deformation degree of the elastic member, thereby controlling the deformation degree of the expansion portion 11. When multiple elastic rods 111 are connected to the connector 112, the connector 112 can synchronously control the multiple elastic rods 111, which is convenient for medical personnel and other operators to accurately and conveniently control the state of the expansion portion 11 in the human body and accurately implement the ablation process. The radially distributed elastic rods 111 radiate the electrodes 2 to the inner wall of the respiratory tract with the core tube as the center, thereby conveniently and accurately implementing annular ablation of the target point.

[0073] In the setting of connector 112, refer to Figure 3b In the disclosed embodiment, the connector 112 includes:

[0074] A central block 1121, the distal ends of the plurality of elastic rods 111 gather together and abut against the outer periphery of the central block 1121;

[0075] The fastening cap 1122 tightens and fixes the plurality of elastic rods 111 together with the central block 1121 .

[0076] By setting the fastening cap 1122, the installation and positioning of the elastic rod 111 can be conveniently and stably realized, the production precision requirement can be reduced, the production efficiency can be improved, and the production cost can be reduced. The center block 1121 is used as a force-applying member to apply the force to the elastic rod 111 to drive the elastic rod 111 to deform, and can synchronously and equally apply the same force to each elastic rod 111, which is convenient for medical personnel and other operators to control the deformation process of the expansion part 11.

[0077] Accordingly, reference Figure 3b In the disclosed embodiment, an adapting structure 1123 for connecting to the pull core 4 is provided on the central block 1121 , and the pull core 4 is used to pull and change the posture of the expansion part 11 .

[0078] 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 adaption 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 adaption 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.

[0079] In different embodiments, the pull core 4 is a solid structure or a hollow structure.

[0080] When in a hollow structure, an auxiliary cooling medium passage is formed inside the core pull 4, and a cooling medium (such as physiological saline) can be introduced to form auxiliary cooling.

[0081] The auxiliary cooling medium passage has various cooperation forms with other structures. For example, in one embodiment, the auxiliary cooling medium passage communicates with the inner cavities of one or more elastic rods 111, and the flow directions can be the same or opposite to form a reflux. For another example, 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 in the central block 1121 to control the on-off state of the auxiliary cooling medium passage.

[0082] The auxiliary cooling medium passage inside the core pull 4 also forms a loop to implement cooling in a way of circulating the cooling medium, and this loop can pass through or not pass through the central block 1121.

[0083] In specific settings, referring to Figure 4 In the disclosed embodiment, the number of the plurality of elastic rods 111 is 3; referring to Figure 2a In the disclosed embodiment, the number of the plurality of elastic rods 111 is 4. There may be more combination ways in specific products.

[0084] The more the number of the elastic rods 111, the more positions where the electrodes 2 can be arranged accordingly, so that it is more convenient to perform annular ablation on the target point. However, an increase in the number of the elastic rods 111 will also increase the difficulty of distal bending of the core tube during the intervention process. Therefore, 3 or 4 are preferably selected.

[0085] The hollow rod can form a channel inside for threading pipelines or transporting fluids. Therefore, specific settings can be selected according to different usage scenarios or design requirements as needed, or different structures can be mixed to meet special needs.

[0086] 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 with an insulating tube.

[0087] Nitinol alloy is convenient for preforming and can be easily deployed 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 damage to normal tissues.

[0088] Referring to Figures 5a to 5bIn the disclosed embodiments, a plurality of delivery tubes are disposed inside the core tube to respectively form delivery channels 13. The plurality of elastic rods 111 are hollow rods, and the proximal ends of the elastic rods 111 communicate with a corresponding one of the delivery tubes. An outlet 131 is formed on the elastic rod 111 and communicates with the cavity 1111 of the elastic rod 111 where it is located.

[0089] The elastic rod 111 being a hollow rod can serve as a delivery tube while ensuring its own deformation effect, reducing the overall volume. More importantly, the elastic rod 111, as the main structural forming component of the expansion part 11, has a relatively high strength of the elastic material itself, and can provide a high-strength delivery tube performance without increasing additional weight, avoiding the situation of cooling failure caused by reasons such as the rupture of the delivery tube. In this embodiment, the cooling medium is transmitted through the cavity 1111 of the elastic rod 111, and the wire still is arranged along the outer wall of the elastic rod 111 and is protected by a sleeve 1112.

[0090] In the setting of the delivery port, refer to Figure 5c In the disclosed embodiments, the outlet 131 and the electrode 2 on the same elastic rod 111 are adjacent to each other, and the outlet 131 is on the distal side of the electrode 2.

[0091] The outlet 131 needs to diffuse the cooling medium onto the tissue near the target point. Therefore, in this embodiment, the outlet 131 and the electrode 2 are arranged adjacent to each other. In terms of the preference of the specific position, in this embodiment, the outlet 131 is located on the distal side of the electrode 2. In some other embodiments, the outlet 131 can be arranged on the proximal side of the electrode 2, or both the distal side and the proximal side are configured with outlets 131, which specifically need to be set according to different usage requirements.

[0092] In the selection of the number of outlets 131, in one embodiment, there are multiple outlets 131 on the same elastic rod 111, and they are arranged along the length direction of the elastic rod 111 where they are located. For example, there are two or three outlets 131 on the same elastic rod 111.

[0093] Increasing the number of outlets 131 can effectively improve the diffusion effect of the cooling medium, thereby stably and uniformly controlling the temperature of the target point and achieving stable ablation. In this embodiment, arranging the outlets 131 in the length direction can further increase the coverage area of the cooling medium and optimize the diffusion effect.

[0094] During the ablation process of the electrode 2, radiofrequency energy needs to be delivered proximally. Wires need to be arranged on the core tube. In Figure 5c In the disclosed embodiments, a sleeve 1112 is provided on the elastic rod 111, a first wire is connected to the electrode 2, and the first wire extends inside the sleeve 1112 to the inside of the core tube and extends proximally.

[0095] The wire is protected by the sleeve 1112, thus avoiding the friction with the respiratory tract and affecting the stability of the wire, which is very important in the interventional field and often directly affects the treatment effect and surgical efficiency. The sleeve 1112 can preferably be a PTFE shrink tube in terms of material.

[0096] 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 abutted against or embedded in the corresponding electrode 2.

[0097] Temperature is a parameter that is relatively easy to observe during the ablation operation and is directly related to the ablation process. The ablation degree and process can be directly controlled through the temperature sensor. The design of the temperature sensor being abutted against or embedded in the electrode 2 can more accurately detect the ablation state of the electrode 2. At the same time, the temperature sensor is separately provided for the electrode 2, providing a structural basis for independently controlling the ablation parameters of multiple electrodes 2.

[0098] In one embodiment, each elastic rod 111 is provided with a sleeve 1112, each sensor is connected with a second wire, and each second wire extends inside the sleeve 1112 to the inside of the core tube and then extends proximally.

[0099] The second wire is protected by the sleeve 1112, thus avoiding the friction with the respiratory tract and affecting the stability of the second wire, ensuring the stability of the temperature sensor reading, and thus improving the accuracy of ablation control. The sleeve 1112 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 1112.

[0100] 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 6 In the disclosed embodiment, 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.

[0101] 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 evenly distributed on the electrode 2. The cooling medium flows out from the infiltration holes 51 and forms a thin film of the cooling medium in the shape of a water film on the outer surface of the electrode 2, so that the electrode surface is infiltrated 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 the impedance balance enables the ablation process to continue until the target ablation volume is reached.

[0102] The pore diameter and density distribution of the infiltration holes 51 can be set according to the flow rate requirements of the heat exchange medium, and a uniform protective film is formed around the electrode as much as possible. For example, the pore diameters of all the infiltration holes 51 are the same, or are set accordingly according to the balance of the heat exchange medium flow rate.

[0103] That is, the pore diameters of the infiltration holes 51 in different regions can be changed to meet the demand for 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 set accordingly according to the balance of the heat exchange medium flow rate.

[0104] When setting accordingly 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 pore diameter of the infiltration hole 51 increases with the increase of the distance from the outflow hole.

[0105] Similarly, for example, the distribution density of the infiltration holes 51 increases with the increase of the distance from the outflow hole.

[0106] 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.

[0107] 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.

[0108] As the main structural member of the expansion part 11, the electrode 2 being wrapped around the elastic rod 111 can ensure the installation effect of the electrode 2, avoid the situation of installation failure due to friction with the respiratory tract tissue during the intervention process, and also ensure that the cooling medium can be stably delivered to the target point.

[0109] In the specific structure of the electrode 2, refer to Figure 6 In the disclosed embodiment, the electrode 2 is a closed structure in the circumferential direction of the elastic rod 111 where it is located.

[0110] 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 tract 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.

[0111] From the perspective of the cooling medium passage, in one embodiment, a distribution groove (not shown in the figure) is further provided in 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 through the distribution groove.

[0112] In terms of the specific usage method, the cage-type radiofrequency ablation catheter disclosed in the present application establishes an intervention path through a bronchoscope. After the bronchoscope reaches the lesion (i.e., the target) position, 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, so that the expansion part 11 contracts and closes to enter the loading state. The core tube assembly 1 is pushed, and it passes 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 to enter the expanded state and expand to make the electrode 2 closely adhere to 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.

[0113] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of 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 falling 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.

[0114] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation to 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 the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A cage-type radiofrequency ablation catheter, comprising a core tube assembly and a plurality of electrodes mounted on the core tube assembly, It is characterized in that The core tube assembly comprises a core tube and an expansion portion connected to the distal end of the core tube; The expansion part in the expanded state is in the shape of a three-dimensional mesh cage, and includes a plurality of hollow elastic rods, one end of the plurality of elastic rods are converged and connected, and the other end is fixedly inserted in the distal end of the core tube, each electrode is fixed on a corresponding elastic rod, and 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; A plurality of delivery pipes are provided in the core tube, one end of each delivery pipe is used to connect to a cooling medium delivery device, and the other end is connected to a corresponding elastic rod. The pull core is a hollow structure, and an auxiliary cooling medium passage is formed inside the pull core, and the auxiliary cooling medium passage is connected to the inner cavity of the elastic rod itself; Each elastic rod is also provided with an output port connected to its own inner cavity, and the position of the output port is adjacent to the electrode on the same elastic rod. The electrode is distributed with multiple infiltration holes connected to the output port. The cooling medium flows out from the infiltration holes to form a cooling medium film on the outer surface of the electrode.

2. The cage-type radiofrequency ablation catheter according to claim 1, It is 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 cage-type radiofrequency ablation catheter according to any one of claims 1 to 2, It is 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 installed on the outer peripheral surface of the working area.

4. The cage-type radiofrequency ablation catheter according to claim 3, It is characterized in that In the loading state opposite to the expansion state, the elastic rods are mutually parallel 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 cage-type radiofrequency ablation catheter according to claim 1, It is characterized in that 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 comprises: A central block, wherein the distal ends of the plurality of elastic rods gather 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 together with the central block; The central block is provided with an adapting structure for connecting a pull core, and the pull core is used for pulling and changing the posture of the expansion part.

6. The cage-type radiofrequency ablation catheter according to claim 5, It is characterized in that The central block is provided with an opening connected to the auxiliary cooling medium passage, and a valve body structure is provided in the central block for controlling the opening / closing of the opening to control the on / off state of the corresponding auxiliary cooling medium passage.

7. The cage-type radiofrequency ablation catheter according to claim 5, It is characterized in that The auxiliary cooling medium passage is communicated with the inner cavities of one or more of the elastic rods to form a reflux, and the auxiliary cooling medium passage formed inside the pull core forms a loop.

8. The cage-type radiofrequency ablation catheter according to claim 1, wherein, a plurality of delivery tubes are disposed inside the core tube to respectively form delivery channels, the plurality of elastic rods are hollow rods, and the proximal ends of the elastic rods are communicated with a corresponding one of the delivery tubes, and the output ports are opened on the elastic rods and communicated with the cavities of the corresponding elastic rods; the output ports and the electrodes on the same elastic rod are adjacent to each other, and the output ports are located on the distal side of the electrodes; there are a plurality of output ports on the same elastic rod, and they are arranged along the length direction of the corresponding elastic rod.

9. The cage-type radiofrequency ablation catheter according to claim 8, wherein, a sleeve is provided on the elastic rod, a first wire is connected to the electrode, and the first wire extends through the inside of the sleeve to the inside of the core tube and extends proximally; the radiofrequency ablation catheter further includes a plurality of temperature sensors, and each temperature sensor is abutted against or embedded in the corresponding electrode; a sleeve is provided on each elastic rod, a second wire is connected to each sensor, and each second wire extends through the inside of the sleeve to the inside of the core tube and then extends proximally.

Images