CN211934272U - Net cage type radio frequency ablation catheter - Google Patents

Abstract

The application discloses a mesh cage type radio frequency ablation catheter, which comprises a core tube assembly and a plurality of electrodes arranged on the core tube assembly, and is characterized in that the core tube assembly comprises a core tube and an expansion part connected to the far end of the core tube; the expansion part has a loading state of radial furling and an expansion state of radial expansion, the expansion part is in a three-dimensional net cage shape in the expansion state, the expansion part comprises a plurality of hollow elastic rods, one ends of the elastic rods are connected in a gathering mode, and the other ends of the elastic rods are fixedly inserted at the far end of the core pipe. The technical scheme that this application is disclosed has realized that the breathing pipeline of core pipe subassembly to different positions, form can both realize stable, convenient, accurate ablation operation through the setting of inflation portion, has improved the efficiency of operation and the effect of treatment.

Description

Net cage type radio frequency ablation catheter

Technical Field

The application relates to the field of interventional therapy, in particular to a radio frequency ablation catheter of a mesh cage type.

Background

Chronic Obstructive Pulmonary Disease (COPD) is the most common Disease of the respiratory system, and has been shown in our country to be around 10% in adults over 40 years of age, based on current epidemiological survey evidence.

Currently, COPD mainly depends on drug therapy, and most of the drugs are anticholinergic drugs for specific blocking of M receptors, which causes relaxation of airway smooth muscle, airway relaxation and reduction of mucus secretion, thereby alleviating airway obstruction and relieving symptoms of COPD patients, while ablation of pulmonary denervation Therapy (TLD) pulmonary denervation therapy aims at parasympathetic nerves, blocks the dominant action thereof, and achieves permanent anticholinergic action. This approach has completed a feasible clinical study in 2015, and further clinical trials are currently underway.

With the continuous improvement of society on COPD and the continuous development of interventional technology, the treatment of chronic obstructive pulmonary disease through airway interventional technology has gained various recognition, and TLD as one of the treatment methods has the advantages of more thorough and more efficient treatment compared with the drug treatment. Therefore, the development of the TLD ablation catheter and the matched equipment thereof is planned to provide technical support for a new method for treating the chronic obstructive pulmonary disease.

As a new trend in recent years to treat COPD, TLD ablation is required to ablate the parasympathetic nerves around the main bronchi, block their innervation, achieve permanent anticholinergic effects, reduce airway smooth muscle tone, reduce mucus secretion, and improve clinical symptoms of chronic obstructive pulmonary disease.

In the ablation process, the inner wall of the main bronchus needs to be ablated in a ring shape, and an ablation point forms a closed ring on the inner wall of the main bronchus, so that effective blocking can be performed.

The inventor finds that most of the ring-shaped catheters in the related technology are electrophysiology mapping catheters, and most of the ablation catheters are single-pole ablation catheters, so that multiple ablations are needed in the treatment process, and the ablations form a closed ring, so that the operation process is complicated, and the treatment effect is not easy to control. The ablation degree is insufficient, and the ablation points are not easy to form a closed ring and are difficult to effectively block; the degree of ablation is excessive, the injury is too large, and the recovery process of the patient is not favorable.

Meanwhile, the inner pipe diameter of the breathing pipeline can be gradually reduced along with the deep intervention, the form of the ablation electrode in the related technology is relatively determined, the adaptability to different arranged target tissues is poor, the ablation position is easily too high, excessive nerve inactivation is caused, and the influence on a patient is large.

SUMMERY OF THE UTILITY MODEL

In order to solve the above problems, the present application discloses a mesh-cage type rf 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 part connected to a distal end of the core tube; the expansion part in an expansion state is in a three-dimensional net cage shape, the expansion part comprises a plurality of hollow elastic rods, one ends of the elastic rods are connected in a gathering mode, the other ends of the elastic rods are fixedly inserted into the far-end part of the core pipe, and each electrode is fixed on one corresponding elastic rod;

a plurality of conveying pipes penetrate through the core pipe, one end of each conveying pipe is used for being connected with a cooling medium conveying device, and the other end of each conveying pipe is communicated with a corresponding elastic rod;

each elastic rod is also provided with an output port communicated with the inner cavity of the elastic rod, and the position of the output port is adjacent to the electrode on the same elastic rod.

Several alternatives are provided below, but not as an additional limitation to the above general solution, but merely as a further addition or preference, each alternative being combinable individually for the above general solution or among several alternatives without technical or logical contradictions.

Optionally, each elastic rod is pre-shaped in a radially folded state, a distal end of each elastic rod is directly or indirectly connected with a pull core, and the pull core extends towards a proximal end to pull the elastic rod to deform so as to enter an expanded state.

Optionally, each elastic rod is pre-shaped to be in a radially expanded state, and the manner of each elastic rod entering the expanded state is as follows:

the expansion state is entered by the elasticity of the self body; or

The far end of each elastic rod is directly or indirectly connected with a pulling core, and the pulling core extends towards the near end and is used for pulling the elastic rods to deform so as to enter an expansion state.

Optionally, in the expanded state, in the axial direction of the core tube, two ends of the expansion part are closed, and the middle part of the expansion part is expanded to form a working area; the electrodes are mounted on the outer peripheral surface of the working area.

Optionally, in a loading state where the expansion state is opposite, the elastic rods are mutually parallel and are contracted in the sheath tube; under the expansion state, each elastic rod is arc-shaped or wave-shaped; the electrodes are arranged at the arc top part or the wave crest part of the corresponding elastic rod.

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

the far ends of the elastic rods are gathered together and attached to the periphery of the central block;

a fastening cap member that fastens and fixes the plurality of elastic rods together with the center block;

the central block is provided with an adaptive structure for connecting a pull core, and the pull core is used for drawing and changing the posture of the expansion part.

Optionally, the pull core is of a solid structure;

or the pull core is of a hollow structure, an auxiliary cooling medium passage is formed in the pull core, and the auxiliary cooling medium passage is communicated or not communicated with the inner cavity of the elastic rod.

Optionally, a plurality of conveying pipes are arranged in the core pipe in a penetrating manner to form conveying channels respectively, and each conveying channel supplies a cooling medium to one of the electrodes; the flow of each delivery pipe is independently controlled.

Optionally, a plurality of conveying pipes penetrate through the core pipe to form conveying channels respectively, the elastic rods are hollow rods, the near ends of the elastic rods are communicated with the corresponding conveying pipes, and the output ports are formed in the elastic rods and communicated with cavities of the elastic rods.

Optionally, the output port and the electrode on the same resilient rod are adjacent to each other, and the output port is on the distal side of the electrode.

Optionally, the output ports on the same elastic rod are multiple and are arranged along the length direction of the elastic rod.

Optionally, a sleeve is arranged on the elastic rod, a first lead is connected to the electrode, and the first lead extends into the core tube through the inside of the sleeve and extends towards the proximal end; the radiofrequency ablation catheter also comprises a plurality of temperature sensors, and each temperature sensor is attached to or embedded in a corresponding electrode; each elastic rod is provided with a sleeve, each sensor is connected with a second lead, and each second lead extends into the core tube through the inside of the sleeve and then extends towards the near end.

Optionally, a plurality of wetting holes communicated 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 wetting holes.

This application has realized that core pipe subassembly to different positions, the breathing pipe way of form can both realize stable, convenient, accurate ablation operation through the net cage setting of inflation portion, has improved the efficiency of operation and the effect of treatment.

Specific advantageous effects will be explained in the detailed description in conjunction with specific examples.

Drawings

FIG. 1 is a schematic view of an exemplary RF ablation catheter;

FIGS. 2 a-2 e are schematic views of an expansion portion in one embodiment;

fig. 3a and 3b are schematic views illustrating the installation of the connector;

FIG. 4 is an enlarged partial schematic view of FIG. 2 d;

FIGS. 5a to 5c are schematic views of cooling medium passages in the first embodiment;

fig. 6 is a schematic view of the wetting holes on the electrode.

The reference numerals in the figures are illustrated as follows:

1. a core tube assembly; 11. an expansion part; 111. an elastic rod; 1111. a cavity; 1112. a sleeve; 112. a connector; 1121. a center block; 1122. a fastening cap; 1123. an adaptation structure; 13. a delivery channel; 131. an output port;

2. an electrode; 4. core pulling; 51. and (6) infiltrating the holes.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The application discloses a mesh cage type radio frequency ablation catheter, which comprises a core tube assembly and a plurality of electrodes arranged on the core tube assembly, wherein the core tube assembly comprises a core tube and an expansion part connected to the far end of the core tube;

the expansion part in an expansion state is in a three-dimensional net cage shape, the expansion part comprises a plurality of hollow elastic rods, one ends of the elastic rods are connected in a gathering mode, the other ends of the elastic rods are fixedly inserted at the far end of the core pipe, and each electrode is fixed on one corresponding elastic rod;

a plurality of conveying pipes penetrate through the core pipe, one end of each conveying pipe is used for being connected with a cooling medium conveying device, and the other end of each conveying pipe is communicated with a corresponding elastic rod;

each elastic rod is also provided with an output port communicated with the inner cavity of the elastic rod, and the position of the output port is adjacent to the electrode on the same elastic rod.

Whether the electrode 2 can approach the target point in an appropriate posture depends on the deformed posture of the expansion portion 11. In the embodiment shown with reference to fig. 2a, the core tube assembly 1 comprises a core tube and an expansion 11;

the core tube has opposite distal and proximal ends, the expansion portion 11 is connected to the distal end of the core tube, and the expansion portion 11 in an expanded state is a three-dimensional netpen shape.

The expansion part 11 has different specifications in the expanded state and the loaded state. When the expansion part 11 is in the loading state, a smaller volume and higher flexibility are required to facilitate intervention operation of medical staff and other operators; when the expansion part 11 is in an expansion state, a larger deformation amount is needed to ensure that the expansion part can be attached to target positions with different inner diameter sizes; when the expansion part 11 enters the expansion state from the installation state, the deformation of the expansion part 11 needs to be controlled linearly, so that the operation of operators such as medical staff is facilitated. In view of the above requirements, the expansion part 11 in this embodiment is preferably in a three-dimensional netpen shape, and the netpen-shaped expansion part 11 can ensure a smaller volume and higher flexibility in a loading state, a larger volume in an expansion state and controllability of a deformation process. The solid mesh cage may be, for example, a sphere, an ellipsoid, a cylinder, etc., but it is required that the geometric shape thereof is very regular and is only a rough shape characteristic, and the density of the mesh cage is not strictly limited.

In one embodiment, the expansion part 11 includes a plurality of solid elastic rods 111, one end of each of the plurality of elastic rods 111 is connected in a converging manner, and the other end is fixedly inserted into a distal portion of the core tube.

The expansion part 11 has elasticity by the elastic rod 111 itself, but the direction of the elasticity can be optimally selected.

For example, in one embodiment, each of the flexible rods 111 is pre-configured to a radially expanded state, and each of the flexible rods 111 is brought into an expanded state by:

the expansion state is entered by the elasticity of the self body; or

The distal end of each elastic rod 111 is directly or indirectly connected with a pull core 4, and the pull core 4 extends towards the proximal end for drawing the elastic rod 111 to deform to enter the expansion state.

The elastic force of the elastic rod 111 can drive the expansion part 11 to enter an expansion state, that is, the expansion part 11 is in an expansion state of radial expansion when no external force is applied, and the expansion part can be generally wrapped and furled by matching with a sheath tube (not shown) sliding relative to the core tube during loading, so as to limit the expansion part 11 in the loading state. At this time, the pull core 4 can be omitted, and the pull core 4 can be matched, so that the posture of the expansion part can be accurately regulated and controlled.

In another embodiment, for example, each of the elastic rods 111 is pre-configured in a radially collapsed state, and a pull core 4 is directly or indirectly attached to a distal end of each of the elastic rods 111, the pull core 4 extending proximally for pulling the elastic rods to deform to enter an expanded state.

The expansion part 11 is in a loading state of being radially folded when no external force is applied, and at this time, the pull core 4 is used in cooperation, and the expansion part is driven to enter an expansion state by the pull core 4.

The elastic bars 111 do not affect the arrangement of the electrodes in the different states of the pre-shaping and are therefore not separately distinguishable below. In the specific arrangement of the electrode 2, with reference to the embodiment shown in fig. 2b, the electrode 2 is arranged on the outer circumferential surface of the expansion part 11.

The outer peripheral surface of the expansion part 11 is the most easily contacted part with the inner wall of the respiratory tract, and the electrode 2 arranged on the outer periphery of the expansion part 11 can conveniently realize the ablation operation of the target tissue. More importantly, the expansion part 11 can be provided with various shapes so as to adapt to different internal tube diameters and shapes of respiratory tracts. On the basis, an electrode can be further arranged on the end face of the far end of the expansion part 11 so as to adapt to the ablation requirement of a specific part.

In the specific arrangement of the expansion part 11, referring to the embodiment shown in fig. 2a to 2b, in the expansion state, in the axial direction of the core tube, both ends of the expansion part 11 are closed, and the middle part is expanded to form a working area; the electrode 2 is mounted on the outer peripheral surface of the working area.

The expansion part 11 can control the expansion degree of the middle part through the distance between the two ends, so that the expansion part is linearly controlled, and the deformation process of the expansion part 11 is accurately controlled by operating personnel such as medical personnel. The electrode 2 is arranged on the peripheral surface of the working area, and the working area is used as the part with the largest volume of the expansion part 11 in the expansion state, so that the electrode can be better attached to the inner wall of the respiratory tract, and the ablation operation can be conveniently realized.

In the embodiment disclosed with reference to fig. 2a, the expansion part 11 comprises a plurality of elastic rods 111, one end of each of the plurality of elastic rods 111 is connected in a converging manner, the other end is fixedly inserted into a distal portion of the core tube, and each of the electrodes 2 is fixed to a corresponding one of the elastic rods 111.

The elastic rod 111 provides a driving force for deformation of the expansion part 11. Since the member directly driving the expansion part 11 to deform has the largest stress among the members, the electrode 2 is provided on the elastic rod 111 to secure the position of the electrode 2 in the respiratory tract, and the success rate of the intervention is increased, thereby improving the treatment efficiency. In other embodiments, a plurality of electrodes may be disposed on the same elastic rod, and the cross-sectional shape of the elastic rod 11 is not limited, and may be circular, rectangular, or elliptical, and the elastic rod 11 itself has a hollow structure for laying lines or transporting materials therein. For a certain elastic rod 11, a single rod body can be used, and a form of multi-strand twisting, or a form of combining a core wire with a spiral coating, etc. can also be used. The near-end of many elastic rods 111 gathers and fixed the grafting at the distal end position of core pipe, and the distal end position of core pipe can adopt elasticity to hoop tightly, and mode such as welding is fixed with the near-end constraint of many elastic rods 111, for the ease of parts such as threading wire, can set up a central support piece, and the near-end of many elastic rods 111 gathers and draws close in this central support piece's periphery, and sets up the hole of dodging that is used for parts such as threading wire on this central support piece.

During the interventional and ablation procedures, the shape of the expansion 11 changes. In the embodiment disclosed with reference to fig. 2d, in the loaded state, the plurality of elastic rods 111 are bundled in parallel with each other; in the expanded state, each elastic rod is arc-shaped.

The elastic rods 111 bundled in parallel can provide smaller volume, and facilitate the implementation of the interventional procedure. Meanwhile, the parallel converging state reduces the deformation stress of the expansion part 11 in the road entering process, and the operation is convenient. The arc-shaped elastic rod can ensure that sharp appearance cannot be formed in the process of intervening in the human body, and unnecessary injury is avoided.

In the loaded state, the resilient rods extend substantially linearly and have a smaller overall outer diameter after collapse to provide passability.

In the specific arrangement position of the electrodes 2, in the embodiment disclosed with reference to fig. 2e, the electrodes 2 are mounted on the arc tips of the respective elastic bars 111.

The arc top portion is a portion where the amount of deformation of the elastic rod 111 is the largest. Electrode 2 installs and can change the deformation of inflation portion 11 into the change of electrode 2 relative position completely at the arc top position, consequently changeable respiratory tract of adaptation that can be better to satisfy complicated treatment demand. Under the inflation state, each elastic rod is the arc, can also understand the wavy structure that multistage arc concatenation formed, and the arc top position is probably more than a department, for example 2 ~ 3 departments in crest position, when setting up a plurality of electrodes on same elastic rod, each electrode sets up respectively in corresponding crest department.

In the spatial arrangement of the elastic rods 111, referring to fig. 3a, one end of each of the elastic rods 111 is connected to a connector 112, and in the expanded state, the elastic rods are radially distributed around the connector 112.

The relative distance between the connector 112 and the distal end of the core tube controls the degree of deformation of the elastic member, and thus the degree of deformation of the expansion 11. Many elastic rods 111 are connected to connector 112, just can realize connector 112 to many elastic rods 111's synchro control, make things convenient for operating personnel such as medical personnel accurate and convenient control inflation portion 11 state in the human body, accurate realization melts the process. The elastic rod 111 with radiation distribution distributes the electrode 2 to the inner wall of the respiratory tract by taking the core tube as the center, thereby conveniently and accurately realizing the annular ablation of the target point.

In the arrangement of the connection head 112, in the embodiment disclosed with reference to fig. 3b, the connection head 112 comprises:

a central block 1121, wherein the distal ends of the elastic rods 111 are gathered together and abut against the periphery of the central block 1121;

and a fastening cap 1122, wherein the fastening cap 1122 fastens and fixes the plurality of elastic rods 111 together with the central block 1121.

Through the setting of fastening cap 1122, the installation and the location of realization elastic rod 111 that can be convenient and firm reduce the requirement of production precision, improve production efficiency, reduction in production cost. The central block 1121, which is a biasing member for applying a biasing force to the elastic rod 111 to drive the elastic rod 111 to deform, can apply the same biasing force to the elastic rods 111 synchronously and equally, and facilitates control of the deformation process of the expansion portion 11 by an operator such as a medical worker.

Correspondingly, in the embodiment disclosed with reference to fig. 3b, the central block 1121 is provided with an adapting structure 1123 for connecting the pull core 4, and the pull core 4 is used for traction to change the posture of the expansion part 11.

The pull core 4 is used to drive the relative distance between the central block 1121 and the distal portion of the core tube, thereby applying a force to the elastic rod 111 to drive the elastic rod 111 to deform. The adaptive structure is disposed at a proximal side of the central block 1121, and is fixed to the central block 1121 in an integrated or separated manner, specifically, the adaptive structure may be a connecting hole, a hook, or the like, and a distal end of the pull core 4 may be inserted into and welded to the connecting hole, or tied and fixed to the hook.

In various embodiments, the pull core 4 has a solid structure or a hollow structure.

In the hollow structure, an auxiliary cooling medium passage is formed inside the core 4, and a cooling medium (e.g., physiological saline) can be introduced to form auxiliary cooling.

The auxiliary cooling medium passage may be in various forms, such as in an embodiment, the auxiliary cooling medium passage communicates with the inner cavity of the elastic rod 111, and the flow directions may be the same or opposite to each other to form a backflow, and for example, in a preferred embodiment, the central block 1121 may have an opening connected to the auxiliary cooling medium passage to directly output the cooling medium, and a valve structure may be disposed in the central block 1121 to control the on/off state of the auxiliary cooling medium passage.

The auxiliary cooling medium passage inside the core 4 also forms a loop for implementing the cooling by means of a circulating cooling medium, which may or may not be via the central block 1121.

In a specific arrangement, in the embodiment disclosed with reference to fig. 4, the number of the plurality of elastic bars 111 is 3; in the embodiment disclosed with reference to fig. 2a, the number of the plurality of resilient bars 111 is 4. There may be more combinations in a particular product.

The more the number of the elastic rods 111 is, the more the positions of the electrodes 2 can be correspondingly arranged, so that the annular ablation on the target point can be realized more conveniently, but the difficulty of bending the distal end of the core tube in the interventional process is increased by increasing the number of the elastic rods 111, and 3 or 4 elastic rods are preferred.

The hollow rod can form a channel inside for threading a pipeline or transporting a fluid. Therefore, the specific setting can be selected according to different use scenes or design requirements, and different structures can be mixed to meet special requirements.

In one embodiment, the elastic rods 111 are made of nitinol, and the elastic rods 111 are insulated from the electrode 2 by plating an insulating layer or wrapping an insulating tube.

The nickel-titanium alloy is convenient to perform, can be conveniently unfolded to a preset shape in a human body, and is convenient for operation of operators such as medical staff; the respiratory tract has changeable and complex shape, except the electrode 2 can contact with the inner wall of the respiratory tract, the elastic rod 111 can also contact with the inner wall of the respiratory tract, and therefore, the elastic rod 111 and the electrode 2 need to be arranged in an insulating way to avoid the damage to normal tissues.

In the embodiment disclosed with reference to fig. 5a to 5b, a plurality of conveying pipes are arranged in the core tube to form the conveying channels 13, the plurality of elastic rods 111 are hollow rods, the proximal ends of the elastic rods 111 are communicated with a corresponding conveying pipe, and the output port 131 is arranged on the elastic rods 111 and is communicated with the cavity 1111 of the elastic rod 111.

The elastic rod 111 is a hollow rod and can be used as a conveying pipe while ensuring the deformation of the elastic rod, so that the whole volume is reduced. More importantly, the elastic rod 111, which is a main structure forming component of the expansion part 11, is made of elastic material with high strength, and can provide high-strength conveying pipe performance without adding extra weight, and the condition of cooling failure caused by breakage of the conveying pipe and the like is avoided. In this embodiment, the cooling medium is transmitted through the cavity 1111 of the flexible rod 111, and the wires are still disposed along the outer side wall of the flexible rod 111 and protected by the sleeve 1112.

In the arrangement of the delivery openings, in the embodiment disclosed with reference to fig. 5c, the delivery opening 131 on the same flexible rod 111 and the electrode 2 are adjacent to each other, and the delivery opening 131 is at the distal side of the electrode 2.

The output 131 needs to diffuse the cooling medium to the tissue near the target point, so in this embodiment the output 131 is placed adjacent to the electrode 2. In another specific position, the output port 131 is located on the distal end side of the electrode 2 in this embodiment, in some other embodiments, the output port 131 may be disposed on the proximal end side of the electrode 2, or the output port 131 is disposed on both the distal end side and the proximal end side, and the specific requirement is set according to different requirements.

In terms of the selection of the number of the output ports 131, in an embodiment, a plurality of output ports 131 are arranged on the same elastic rod 111 and are arranged along the length direction of the elastic rod 111. For example, two or three output ports 131 are provided on the same resilient lever 111.

The increase of the number of the output ports 131 can effectively improve the diffusion effect of the cooling medium, so that the temperature of the target point can be stably and uniformly controlled, and stable ablation can be realized. In this embodiment, the arrangement of the output ports 131 in the length direction can further increase the coverage area of the cooling medium and optimize the diffusion effect.

The electrode 2 requires proximal delivery of radio frequency energy during ablation. Wires need to be arranged on the core tube. In the embodiment disclosed in fig. 5c, the flexible rod 111 is provided with a sleeve 1112, and the electrode 2 is connected with a first wire extending through the interior of the sleeve 1112 into the core and proximally.

The lead is protected by the sleeve 1112 so as to avoid friction with the respiratory tract affecting the stability of the lead, which is important in the interventional field and often directly affects the efficacy of the treatment and the efficiency of the procedure. The sleeve 1112 may be preferably a PTFE shrink tube in material.

During the ablation procedure, the ablation status of the electrode 2 and the extent of ablation need to be controlled by a number of parameters. In one embodiment, the radiofrequency ablation catheter further comprises a plurality of temperature sensors, each temperature sensor being applied against or embedded in a respective electrode 2.

The temperature is a parameter which is easier to observe in the ablation operation and is directly related to the ablation process, and the ablation degree and the process can be directly controlled through the temperature sensor. The temperature sensor is attached to or embedded in the electrode 2, so that the ablation state of the electrode 2 can be detected more accurately. Meanwhile, the electrodes 2 are provided with temperature sensors independently, and a structural basis is provided for independently controlling the ablation parameters of the electrodes 2.

In one embodiment, a sleeve 1112 is disposed on each flexible rod 111, a second wire is connected to each sensor, and each second wire extends into the core tube and proximally through the sleeve 1112.

The second wire is protected by the sleeve 1112, so that friction between the second wire and the respiratory tract is prevented from influencing the stability of the second wire, the stability of reading of the temperature sensor is ensured, and the precision of ablation control is improved. The sleeve 1112 may be preferably a PTFE shrink tube in material. In connection with the previous embodiments, the first and second wires may be encased within the same sleeve 1112.

In addition to natural diffusion of the cooling medium when it is diffused to the target, the infiltration holes 51 may be designed to enhance the diffusion effect. Referring to fig. 6, in the embodiment, a plurality of wetting holes 51 communicated with the output ports 131 are distributed on the electrode 2, and the cooling medium from the output ports 131 is distributed to the periphery of the electrode 2 through the wetting holes 51.

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 plurality of fine infiltration holes 51 are uniformly distributed on the electrode 2. The cooling medium flows out from the infiltrating holes 51, and a thin cooling medium film in the form of a water film is formed on the outer surface of the electrode 2, so that the surface of the electrode is infiltrated by the cooling medium (in the embodiment, the cooling medium is normal saline), further avoiding the scab of the ablation tissue, and reducing the loop impedance. Maintaining impedance balance allows the ablation process to continue until the target ablation volume is reached.

The pore size and density distribution of the wetting holes 51 can be set according to the flow demand of the heat exchange medium, so as to ensure that a uniform protective film is formed on the periphery of the electrode as much as possible, for example, all the wetting holes 51 have the same pore size, or are set according to the flow balance of the heat exchange medium.

I.e., the size of the wetting holes 51 in different areas can be varied to accommodate the need for uniform flow. In the same way, the distribution density of all the infiltrating holes 51 at different parts of the electrode 2 is the same, or the infiltrating holes are correspondingly arranged according to the flow balance of the heat exchange medium.

When the heat exchange medium flow rate is balanced and correspondingly set, the arrangement mode of the heat exchange medium flow channel outlet is mainly considered, for example, the aperture of the wetting hole 51 increases with the distance from the outflow hole.

Similarly, for example, the distribution density of the wetting holes 51 increases with distance from the outlet holes.

The wetting holes 51 may be arranged as desired during processing, for example, in one embodiment, the wetting holes 51 are distributed in a plurality of groups along the circumference of the electrode 2.

In one embodiment, the expansion part 11 includes a plurality of elastic rods 111, one end of each of the plurality of elastic rods 111 is connected in a converging manner, the other end of each of the plurality of elastic rods 111 is fixedly inserted into a distal portion of the core tube, and each of the electrodes 2 is fixed to a corresponding one of the plurality of elastic rods 111.

The elastic rod 111 is used as a main structural part of the expansion part 11, the electrode 2 is wrapped on the elastic rod 111, the installation effect of the electrode 2 can be ensured, the situation that the installation fails due to friction with tissues of a respiratory tract in the intervention process is avoided, and the cooling medium can be stably conveyed to a target point.

Specific structure of the electrode 2, in the embodiment disclosed with reference to fig. 6, the electrode 2 is a closed structure in the circumferential direction of the elastic rod 111.

Accordingly, in one embodiment, the electrode 2 is in a non-closed configuration around the circumference of the flexible rod 111. The electrode 2 with the closed structure can ensure a good connection relation with the elastic rod 111, and can provide enough strength in some treatment scenes in which the electrode 2 needs to be in stressed contact with the tissues of the respiratory tract. Therefore, the installation mode of the specific electrode 2 can be selected according to the use scene and the design index.

In view of the passage of the cooling medium, in an embodiment, a distribution groove (not shown) is further provided in the electrode 2, and the cooling medium from the output port 131 is supplied to the wetting holes 51 at the periphery of the corresponding electrode 2 through the distribution groove.

In a specific using method, the netpen type radiofrequency ablation catheter disclosed by the application establishes an interventional passage through a bronchoscope, after the bronchoscope reaches a focus (namely a target point), a sheath tube with a core tube assembly 1 is plugged into the bronchoscope, an adjustable knob is twisted, a pull core 4 is loosened, the expansion part 11 is contracted and gathered to enter a loading state, the core tube assembly 1 is pushed to pass 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, a handle at the near end is rotated to adjust the position of an electrode 2, after the adjustment is completed, the adjustable knob is rotated, the pull core 4 is pulled, the expansion part 11 is driven to enter the expansion state, the expansion part is expanded and adjusted to be close to the inner wall of a bronchus well by the electrode 2, then a cooling medium is introduced, cold saline is adopted in the embodiment, then the radiofrequency instrument is opened, and the plurality of electrodes 2 are ablated (the cold saline pump is used for adjusting, if the temperature is higher than 60 ℃, the saline flow rate is increased, if the temperature is not higher than 60 ℃, the flow rate is kept unchanged, the saline flow rate is adjusted within the range of 3-15 ml/min), the ablation power range is 3-10W, the ablation time is 60s-120s, the bronchoscope is matched with and pumps out redundant saline in the cavity channel during ablation, after ablation is completed, the pull core 4 is loosened through the adjustable knob, the expansion part 11 naturally enters a loading state by means of the self elasticity of the elastic rod 111, the ablation position is adjusted, the next round of ablation is carried out, and finally a closed loop is formed at the ablation point on the inner wall of the main bronchus. If the ablation point is observed through the bronchoscope and the ablation point is not closed, the expansion part 11 is adjusted to enable one electrode 2 to be in the gap position, and the monopolar ablation is carried out until the ablation point forms a closed loop.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features. When technical features in different embodiments are represented in the same drawing, it can be seen that the drawing also discloses a combination of the embodiments concerned.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. The mesh cage type radio frequency ablation catheter comprises a core tube assembly and a plurality of electrodes arranged on the core tube assembly, and is characterized in that the core tube assembly comprises a core tube and an expansion part connected to the far end of the core tube;

the expansion part in an expansion state is in a three-dimensional net cage shape, the expansion part comprises a plurality of hollow elastic rods, one ends of the elastic rods are connected in a gathering mode, the other ends of the elastic rods are fixedly inserted into the far-end part of the core pipe, and each electrode is fixed on one corresponding elastic rod;

a plurality of conveying pipes penetrate through the core pipe, one end of each conveying pipe is used for being connected with a cooling medium conveying device, and the other end of each conveying pipe is communicated with a corresponding elastic rod;

each elastic rod is also provided with an output port communicated with the inner cavity of the elastic rod, and the position of the output port is adjacent to the electrode on the same elastic rod.

2. The mesh-cage rf ablation catheter of claim 1, wherein each of the flexible rods is pre-configured to a radially collapsed state, and a pull core is directly or indirectly attached to a distal end of each of the flexible rods, said pull core extending proximally for pulling the flexible rods to deform into the expanded state.

3. The mesh-cage rf ablation catheter of claim 1, wherein each of the flexible rods is pre-configured to a radially expanded state, and wherein each of the flexible rods is brought into an expanded state by:

the expansion state is entered by the elasticity of the self body; or

The far end of each elastic rod is directly or indirectly connected with a pulling core, and the pulling core extends towards the near end and is used for pulling the elastic rods to deform so as to enter an expansion state.

4. The mesh-cage type radio frequency ablation catheter according to any one of claims 1 to 3, wherein in an expanded state, in the axial direction of the core tube, two ends of the expansion part are closed, and the middle part is expanded to form a working area; the electrodes are mounted on the outer peripheral surface of the working area.

5. The mesh-cage rf ablation catheter of claim 4, wherein the flexible rods are constrained within the sheath in parallel with one another in a loaded state as opposed to an expanded state; under the expansion state, each elastic rod is arc-shaped or wave-shaped; the electrodes are arranged at the arc top part or the wave crest part of the corresponding elastic rod.

6. The mesh-cage rf ablation catheter of claim 1, wherein one end of said plurality of flexible rods is connected to a connector and radially distributed about said connector in an expanded state; the connector includes:

the far ends of the elastic rods are gathered together and attached to the periphery of the central block;

a fastening cap member that fastens and fixes the plurality of elastic rods together with the center block;

the central block is provided with an adaptive structure for connecting a pull core, and the pull core is used for drawing and changing the posture of the expansion part.

7. The mesh-cage rf ablation catheter of claim 6 wherein said pull core is a solid structure;

or the pull core is of a hollow structure, an auxiliary cooling medium passage is formed in the pull core, and the auxiliary cooling medium passage is communicated or not communicated with the inner cavity of the elastic rod.

8. The mesh-cage type radiofrequency ablation catheter of claim 1, wherein a plurality of delivery tubes are arranged in the core tube in a penetrating manner to form delivery channels respectively, the plurality of elastic rods are hollow rods, proximal ends of the elastic rods are communicated with the corresponding delivery tubes, and the output ports are arranged on the elastic rods and are communicated with cavities of the elastic rods;

the output port and the electrode on the same elastic rod are adjacent to each other, and the output port is positioned on the far end side of the electrode;

the delivery outlet on same elastic rod is a plurality of, and arranges along the length direction of place elastic rod.

9. The mesh-cage rf ablation catheter of claim 8, wherein a sleeve is disposed over said flexible shaft, and a first wire is attached to said electrode and extends proximally into said core through the interior of said sleeve; the radiofrequency ablation catheter also comprises a plurality of temperature sensors, and each temperature sensor is attached to or embedded in a corresponding electrode; each elastic rod is provided with a sleeve, each sensor is connected with a second lead, and each second lead extends into the core tube through the inside of the sleeve and then extends towards the near end.

10. The mesh-cage rf ablation catheter of claim 1, wherein the electrode has a plurality of wetting holes distributed therein and communicating with the output port, and wherein the cooling medium from the output port is distributed to the periphery of the electrode through the wetting holes.

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