Radio frequency ablation catheter and radio frequency ablation system

Abstract

Provided in the present disclosure are a radio frequency ablation catheter and a radio frequency ablation system. The radio frequency ablation catheter comprises: a balloon, an inner tube, a guide wire tube, an outer sleeve, and a radio frequency electrode. A proximal end of the balloon is provided with a proximal tube section extending along a longitudinal axis thereof. The inner tube is provided with an inflation cavity and a guide wire tube penetration cavity that are not in communication with each other. A distal end of the inner tube is inserted into the proximal tube section, and the inner tube is hermetically connected to the proximal tube section. A distal end of the inflation cavity is in communication with an inner cavity of the balloon. A distal section portion of the guide wire tube extends from a distal end of the guide wire tube penetration cavity and extends to the inner cavity of the balloon, and the guide wire tube is hermetically connected to the guide wire tube penetration cavity. The outer sleeve sleeves the inner tube. A distal end of the outer sleeve is connected to the proximal tube section, and a gap is formed at the joint. A threading cavity between the outer sleeve and the inner tube is used for accommodating a cable. The radio frequency electrode has a distal ablation region and a proximal wiring region connected to the cable. From the proximal wiring region to the distal ablation region, the radio frequency electrode extends along the threading cavity to the gap, passes through the gap, and then extends against a surface of the proximal tube section to an outer surface of the balloon.

Description

Radiofrequency ablation catheters and radiofrequency ablation systems Cross-references

[0001] This disclosure incorporates, in its entirety, Chinese Patent Application No. 202411942999.1, filed on December 26, 2024, entitled “Radiofrequency Ablation Catheter and Radiofrequency Ablation System”, which is incorporated herein by reference. Technical Field

[0002] This disclosure relates to the field of medical device technology, and in particular to a radiofrequency ablation catheter and radiofrequency ablation system. Background Technology

[0003] Radiofrequency ablation (RFA) is widely used in the medical field. Its working principle involves applying radiofrequency current to target tissue (such as tumors or heart lesions). When the radiofrequency current flows through the target tissue, the rapid change in the electromagnetic field causes polarized water molecules within the tissue to move at high speed, generating heat. This leads to the evaporation of intracellular water and protein denaturation, thereby inducing tissue necrosis and achieving the therapeutic goal. RFA has applications in the treatment of many diseases. For example, it can treat arrhythmias by using radiofrequency energy to process abnormal pathways in the electrical signal conduction of heart tissue, restoring the heart's normal rhythm; it can also use the thermal effect of radiofrequency to induce coagulative necrosis of tissue to remove tumors; and it can treat chronic pain and neurological diseases by using radiofrequency energy to process specific nerve areas and destroy pathological nerve conduction through high temperatures.

[0004] Currently, a commonly used medical device for radiofrequency ablation (RFA) treatment is the RFA catheter, which has an electrode made of metal attached to its distal end. During treatment, the RFA catheter is inserted into the patient's body through a natural cavity (such as a blood vessel), with the distal end reaching the target tissue. The electrode contacts the target tissue and discharges, and the radiofrequency current is conducted along the electrode to the target tissue. However, in actual treatment, the electrode often fails to make sufficient contact with the target tissue, affecting the treatment outcome. Summary of the Invention

[0005] This disclosure provides a radiofrequency ablation catheter and a radiofrequency ablation system, wherein the electrode can make good contact with the target tissue, thereby improving the treatment effect.

[0006] According to a first aspect of this disclosure, a radiofrequency ablation catheter is provided, comprising: an inflatable balloon, an inner tube, a guidewire, an outer tube, and a radiofrequency electrode; the proximal end of the balloon is provided with a proximal tube segment extending along its own longitudinal axis; the inner tube has a multi-lumen structure, having an inflation cavity and a guidewire insertion cavity that are not interconnected, the distal end of the inner tube being inserted into the proximal tube segment, and the outer wall of the inner tube being sealed to the inner wall of the proximal tube segment, the distal end of the inflation cavity communicating with the inner lumen of the balloon; the guidewire is inserted into the guidewire insertion cavity, and the distal portion of the guidewire is self-guided. The distal end of the guidewire insertion cavity extends into the inner cavity of the balloon, and the outer wall of the guidewire is sealed to the guidewire insertion cavity. The outer tube is sleeved outside the inner tube, and the distal end of the outer tube is connected to the proximal tube segment, with a gap forming at the joint. The groin between the inner wall of the outer tube and the outer wall of the inner tube is used to accommodate the cable. The radiofrequency electrode has a proximal wiring area and a distal ablation area, and the proximal wiring area is connected to the cable. From the proximal wiring area to the distal ablation area, the radiofrequency electrode extends along the groin to the gap, and after exiting the gap, it extends against the surface of the proximal tube segment to the outer surface of the balloon.

[0007] The radiofrequency ablation catheter of this embodiment utilizes a balloon to support and carry the radiofrequency electrode. The inflated balloon allows the radiofrequency electrode to better adhere to the target tissue, thereby improving treatment efficacy. This embodiment also utilizes a grooving cavity between the inner wall of the outer sheath and the outer wall of the inner tube to provide space for the proximal wiring area and cable of the radiofrequency electrode. This ensures that the connection point of the proximal wiring area and cable is located within the grooving cavity and not exposed to the surrounding environment. This reduces the likelihood of friction between the connection point and tissue during treatment, which could cause the proximal wiring area and cable to break or the radiofrequency electrode to shift, thus improving the reliability of the radiofrequency ablation catheter.

[0008] In some embodiments, the radio frequency electrode is bonded to the outer sleeve and the proximal tube segment at the gap using sealant, thereby sealing the gap.

[0009] In some embodiments, the central axis of the inner tube is eccentrically positioned relative to the central axis of the outer tube.

[0010] In some embodiments, both the inner tube and the outer tube have circular cross-sections, and the eccentricity between the inner tube and the outer tube is close to the difference between the inner diameter and the outer diameter of the outer tube.

[0011] In some embodiments, the central axis of the inflation chamber is further away from the central axis of the outer sheath than the central axis of the guide wire entering the chamber.

[0012] In some embodiments, the radio frequency electrode includes at least a flexible metal electrode layer, a liner layer, a first flexible conductor layer, a substrate layer, and a second flexible conductor layer, which are sequentially stacked from the outer surface to the inner surface of the balloon. The liner layer and the substrate layer are flexible insulating material layers. The substrate layer is provided with conductive vias. The distal ends of the first flexible conductor layer and the distal ends of the second flexible conductor layer are connected through the conductive vias. The portion of the flexible metal electrode layer located in the proximal wiring area is connected to the radio frequency cable in the wiring cavity. The portions of the first flexible conductor layer and the second flexible conductor layer located in the proximal wiring area are respectively connected to two conductive cables in the wiring cavity to form a thermocouple circuit.

[0013] In some embodiments, the distal ablation zone facing the balloon is further provided with a radiopaque section.

[0014] In some embodiments, the developing section is a closed ring structure, the developing section is disposed at the edge of the distal ablation zone and the configuration of the developing section is adapted to the configuration of the distal ablation zone, or the developing section is a plurality of developing points, the plurality of developing points being distributed at intervals along the outer periphery of the distal ablation zone.

[0015] In some embodiments, the developing section is a platinum-iridium alloy developing section, wherein the platinum mass percentage in the platinum-iridium alloy is 90% and the iridium mass percentage is 10%; and / or, the thickness of the developing section is greater than or equal to 0.03 mm and less than or equal to 0.07 mm.

[0016] In some embodiments, the radiofrequency ablation catheter further includes a contrast-enhancing element disposed on the periphery of the distal portion and located within the lumen of the balloon; and / or, the total thickness of the radiofrequency electrodes is less than or equal to 0.2 mm.

[0017] In some embodiments, the radiofrequency ablation catheter further includes a handle, a conduit, and a plug. The proximal end of the outer tube is connected to one end of the handle, and the other end of the handle is connected to the distal end of the conduit. The plug is located at the proximal end of the conduit. The cable extends from the proximal end connected to the plug to the distal end connected to the proximal wiring area, along the lumen of the conduit to the handle, and after passing through the internal channel of the handle, it extends into the conduit cavity.

[0018] In some embodiments, the handle includes an upper cover, a lower cover, and a connecting seat. The upper cover and the lower cover are fastened together to form a receiving space. A portion of the connecting seat is received within the receiving space. The connecting seat has a first port connected to the inner tube, a second port communicating with the guide wire insertion cavity, and a side port communicating with the inflation cavity. The second port and the side port are each connected to a Luer connector. The Luer connector connected to the second port is used for the guide wire to pass through, and the Luer connector connected to the side port is used for the introduction of pressurized gas.

[0019] According to a second aspect of this disclosure, a radiofrequency ablation system is provided, comprising: a radiofrequency ablation device and a radiofrequency ablation catheter of any one of the first aspects of this disclosure.

[0020] These and other aspects of this disclosure will be apparent from the embodiments described below, and will be elucidated with reference to the embodiments described below. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments of this disclosure will be briefly described below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort. In the following description of exemplary embodiments in conjunction with the accompanying drawings, more details, features, and advantages of this disclosure are disclosed, in which:

[0022] Figure 1 is a schematic diagram of the structure of a radiofrequency ablation catheter according to some embodiments of the present disclosure;

[0023] Figure 2 is a schematic diagram of the structure at point A in Figure 1;

[0024] Figure 3 is a cross-sectional schematic diagram of the radiofrequency ablation catheter shown in Figure 2;

[0025] Figure 4 is a partial structural schematic diagram of the radiofrequency ablation catheter shown in Figure 1;

[0026] Figure 5 is a schematic diagram of the structure of radio frequency electrodes according to some embodiments of this disclosure;

[0027] Figure 6 is a top view of the radiofrequency ablation catheter shown in Figure 1;

[0028] Figure 7 is a schematic diagram of the radiofrequency ablation catheter shown in Figure 1.

[0029] Explanation of reference numerals in the attached drawings: 100-Radiofrequency ablation catheter; 10-Balloon; 11-Proximal segment; 12-Tip portion; 20-Inner tube; 21-Inflation chamber; 22-Guidewire insertion chamber; 30-Guidewire; 31-Illuminating element; 32-Distal portion; 40-Outer tube; 41-Wire insertion chamber; 50-Radiofrequency electrode; 51-Distal ablation zone; 511-Illuminating section; 52-Proximal connection area; 53-Flexible metal electrode layer; 54-Backing plate layer; 55-First flexible conductor layer; 56-Substrate layer; 561-Conductive via; 57-Second flexible conductor layer; 58-Coating layer; 581-First window; 582-Second window; 59-Back membrane layer; 591-Third window; 592-Fourth window; 50a, 50b, 50c, 50d-Coatings; 60 - Handle; 61 - Top cover; 62 - Bottom cover; 63 - Connector; 64, 64a, 64b - Luer connector; 70 - Conduit; 80 - Plug; 90 - Cable. Detailed Implementation

[0030] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this disclosure. Therefore, the drawings and description are to be considered exemplary in nature and not restrictive.

[0031] As used herein, the term “about” or “approximately” for any numerical or numerical range indicates that a portion or assembly of multiple parts is permitted to perform the appropriate dimensional tolerances for their intended purpose as described herein. More specifically, “about” or “approximately” may refer to a range of enumerated values ​​±20%, for example, “about 90%” may refer to a range of values ​​from 71% to 99%.

[0032] Additionally, as used herein, the terms “patient,” “host,” and “user” refer to any human or animal subject and are not intended to limit the system or method or use to human use.

[0033] Figure 1 is a schematic diagram of the structure of a radiofrequency ablation catheter according to some embodiments of the present disclosure, Figure 2 is a schematic diagram of the structure at point A in Figure 1, and Figure 3 is a cross-sectional schematic diagram of the radiofrequency ablation catheter shown in Figure 2. Referring to Figures 1 to 3, the radiofrequency ablation catheter 100 includes: a balloon 10, an inner tube 20, a guidewire tube 30, an outer tube 40, and a radiofrequency electrode 50. The balloon 10 is configured to be inflatable and collapsible, and a proximal tube segment 11 extending along its own longitudinal axis is provided at the proximal end of the balloon 10. The inner tube 20 has a multi-lumen structure, and the inner tube 20 has an inflation chamber 21 and a guidewire insertion chamber 22 that are not interconnected. The inflation chamber 21 is used to transmit pressurized gas. The distal end of the inner tube 20 is inserted into the proximal tube segment 11, and the outer wall of the inner tube 20 is sealed to the inner wall of the proximal tube segment 11. The distal end of the inflation chamber 21 communicates with the inner lumen of the balloon 10. A guidewire 30 is inserted into the guidewire insertion cavity 22. The distal portion 32 of the guidewire 30 extends from the distal end of the guidewire insertion cavity 22 and extends into the inner cavity of the balloon 10. The outer wall of the guidewire 30 is sealed to the guidewire insertion cavity 22. An outer sleeve 40 is fitted over the inner tube 20. The distal end of the outer sleeve 40 is connected to the proximal tube segment 11, and a gap is formed at the joint. The groin 41 between the inner wall of the outer sleeve 40 and the outer wall of the inner tube 20 is used to accommodate the cable (a single "cable" or multiple "cables" are collectively referred to as "cable 90"). The radiofrequency electrode 50 has a proximal connection area 52 and a distal ablation area 51. The proximal connection area 52 is connected to the cable 90. From the proximal connection area 52 to the distal ablation area 51, the radiofrequency electrode 50 extends along the groin 41 to the gap, and after exiting the gap, extends against the surface of the proximal tube segment 11 to the outer surface of the balloon 10.

[0034] In this embodiment, taking balloon 10 as an example, the end of balloon 10 or its components closer to the operator in the extension direction is defined as the "proximal end," and similarly, the end of balloon 10 or its components further away from the operator in the extension direction is defined as the "distal end." The definitions of "proximal end" and "distal end" for components such as inner tube 20, guidewire 30, and outer tube 40 can be referenced to balloon 10 and will not be repeated here. A "side opening" is defined as an orifice located on the side surface of the component, and a "port" is defined as an orifice located on the end face of the component.

[0035] As shown in Figures 2 and 3, the distal portion 32 of the guidewire 30 can be coaxially arranged with the balloon 10. Furthermore, the distal portion 32 of the guidewire 30 can also be designed to extend from the distal end of the balloon 10 into the lumen. In some embodiments, the radiofrequency ablation catheter 100 may further include a tip portion 12 located outside the balloon 10. The outer surface of the tip portion 12 is an arcuate surface formed by rotating about its own longitudinal axis. The tip portion 12 is coaxially arranged and connected with the distal portion 32. Thus, the guidewire, inserted into the guidewire 30, extends from the distal portion 32, passes through the tip portion 12, and then exits from the tip portion 12. By designing the tip portion 12, and ensuring its smooth outer surface, not only can the resistance to its movement in natural cavities be reduced, allowing for smoother insertion, but it also helps to reduce the possibility of the tip portion 12 damaging the patient's tissues during the advancement and treatment of the radiofrequency ablation catheter 100. The material of the tip portion 12 can be at least one of polyamide, polyether block polyamide, and polyurethane.

[0036] The methods for achieving a sealed connection between the outer wall of the inner tube 20 and the inner wall of the proximal tube segment 11 include, but are not limited to, the following possible examples. For example, a sealing ring can be fitted over the inner tube 20 to seal the gap between the outer wall of the inner tube 20 and the inner wall of the proximal tube segment 11. For example, the outer wall of the inner tube 20 and the inner wall of the proximal tube segment 11 can be connected using a sealant (e.g., silicone, epoxy resin, etc.). For example, if both the inner tube 20 and the proximal tube segment 11 are made of thermoplastic materials, the outer wall of the inner tube 20 and the inner wall of the proximal tube segment 11 can also be connected and sealed using a heat-fusion connection. The method for achieving a sealed connection between the outer wall of the guide wire tube 30 and the guide wire tube insertion cavity 22 is similar and will not be described in detail here.

[0037] When using the radiofrequency ablation catheter 100 of this embodiment for treatment, the operator folds and rolls the balloon 10 to reduce its volume, then inserts the radiofrequency ablation catheter 100 into the patient's body, pushes the radiofrequency ablation catheter 100 to the target tissue, and then inputs pressurized gas into the inflation chamber 21. The pressurized gas flows into the inner cavity of the balloon 10 along the inflation chamber 21, and the pressure in the inner cavity of the balloon 10 increases and it expands. The radiofrequency electrode 50 comes into contact with the target tissue, and then the radiofrequency energy generator of the radiofrequency ablation device is operated to transmit radiofrequency current to the radiofrequency electrode 50. The radiofrequency current is applied to the target tissue through the radiofrequency electrode 50 to achieve ablation.

[0038] The radiofrequency ablation catheter 100 of this embodiment utilizes a balloon 10 to support and carry the electrode. The inflatable balloon 10 allows the electrode to better adhere to the target tissue, thereby improving treatment efficacy. This embodiment also utilizes a grooving cavity 41 between the inner wall of the outer sheath 40 and the outer wall of the inner tube 20 to provide a space for the proximal wiring area 52 of the radiofrequency electrode 50 and the cable 90. This ensures that the connection point of the proximal wiring area 52 and the cable 90 is located within the grooving cavity 41 and not exposed to the surrounding environment. This reduces the likelihood of friction between the connection point and tissue during treatment, which could cause the proximal wiring area 52 and the cable 90 to break or the radiofrequency electrode 50 to shift, thus improving the reliability of the radiofrequency ablation catheter 100. Based on this, by designing a sealed connection between the outer wall of the inner tube 20 and the inner wall of the proximal tube segment 11, and a sealed connection between the outer wall of the guide wire tube 30 and the guide wire tube insertion cavity 22, the independence between the inflation cavity 21, the guide wire tube insertion cavity 22, and the threading cavity 41 can be improved. This helps to reduce the possibility of pressurized gas escaping from the gap, thus ensuring the inflation effect of the balloon 10 and enabling the electrode to better adhere to the target tissue.

[0039] To further reduce the possibility of pressurized gas escaping from the gap, in some embodiments of this disclosure, the radiofrequency electrode 50 can also be bonded to the outer sleeve 40 and the proximal tube segment 11 at the gap using sealant, thereby sealing the gap. In the fabrication process of the radiofrequency ablation catheter 100 of this embodiment, the guidewire 30 and the guidewire of the inner tube 20 can be first fitted together in the cavity 22 and then sealed. Next, the inner tube 20 and the proximal tube segment 11 can be fitted together and sealed. Then, the outer sleeve 40 is fitted over the inner tube 20, and the outer sleeve 40 and the proximal tube segment 11 are connected.

[0040] The positional relationship between the inner tube 20 and the outer tube 40 is varied. In some embodiments of this disclosure, the inner tube 20 and the outer tube 40 can be coaxially arranged, in which case the suture cavity 41 formed between them is annular and the size of the annular suture cavity 41 is equal everywhere in the direction perpendicular to the longitudinal axis of the inner tube 20. As an alternative embodiment, as shown in FIG4, the central axis of the inner tube 20 can also be eccentrically arranged relative to the central axis of the outer tube 40, wherein FIG4 is a partial structural schematic diagram of the radiofrequency ablation catheter 100 shown in FIG1. ​​By making the inner tube 20 and the outer tube 40 non-coaxial, the size of the suture cavity 41 formed between them is not equal everywhere. In this example, the maximum value d1max of the size of the suture cavity 41 in the first direction (shown as Y in FIG4) perpendicular to the longitudinal axis of the inner tube 20 and the maximum value d2max of the size in the second direction (shown as X in FIG4) perpendicular to the longitudinal axis of the inner tube 20 are both larger, wherein the first direction and the second direction are perpendicular to each other. This has two advantages: first, it allows for more concentrated storage of the cable 90 within the limited space of the cable cavity 41; second, the cable cavity 41 can accommodate a larger near-side wiring area 52, thus relaxing the size restrictions on the near-side wiring area 52 of the radio frequency electrode 50.

[0041] In some embodiments, when the central axis of the inner tube 20 is eccentrically set relative to the central axis of the outer tube 40, as shown in FIG4, the cross-sections of both the inner tube 20 and the outer tube 40 can be circular, and the eccentricity ΔD between the inner tube 20 and the outer tube 40 is close to the difference between the inner diameter D1 of the outer tube 40 and the outer diameter D2 of the inner tube 20. That is, ΔD is approximately D1-D2. In this example, the cross-section of the threading cavity 41 is approximately crescent-shaped. With this setting, the inner tube 20 is in contact with or near contact with the inner wall of the outer tube 40, which is beneficial to maximize d1max and d2max. Of course, in other embodiments of this disclosure, the cross-sections of the inner tube 20 and the outer tube 40 can also be selected from elliptical, rectangular, oblong, etc. The cross-sectional shape of the guide wire insertion cavity 22 and the inflation cavity 21 in this embodiment is also not limited, for example, it can be selected from circular, semi-circular, elliptical, rectangular, oblong, etc. As an example, as shown in Figure 4, the cross-section of the guide wire insertion cavity 22 is circular, and the cross-section of the inflation cavity 21 is arc-shaped. The cross-section of the inflation cavity 21 has an arc-shaped profile and a straight profile, and the arc-shaped profile and the straight profile are connected to form a closed shape.

[0042] In some embodiments of this disclosure, the central axis of the inflation chamber 21 can be configured to be further away from the central axis of the outer sheath 40 than the central axis of the guidewire insertion chamber 22. Thus, in Figure 4, the inflation chamber 21 is located below the guidewire insertion chamber 22. Compared to the configuration where the guidewire insertion chamber 22 is located below the inflation chamber 21, this design in this embodiment prevents the center of gravity of the guidewire 30, which passes through the guidewire insertion chamber 22, from shifting excessively from the center of the outer sheath 40. It also prevents the center of gravity of the balloon 10, which is coaxially arranged with the distal portion 32, from shifting excessively from the center of the outer sheath 40, thereby improving the balance and reliability of the radiofrequency ablation catheter 100.

[0043] Figure 5 is a schematic diagram of the structure of the radiofrequency electrode 50 according to some embodiments of this disclosure. As shown in Figure 5, in some embodiments of this disclosure, the radiofrequency electrode 50 may include at least a flexible metal electrode layer 53, a liner layer 54, a first flexible conductor layer 55, a substrate layer 56, and a second flexible conductor layer 57, sequentially stacked from the outer surface to the inner surface of the balloon 10. The liner layer 54 and the substrate layer 56 are flexible insulating material layers. The flexible insulating material may be polyimide (PI), polyethylene terephthalate (PET), polyurethane (PU), or a combination thereof. Therefore, each layer of the radiofrequency electrode 50 in this embodiment is flexible, and the radiofrequency electrode 50 as a whole has good flexibility. The radiofrequency electrode 50 can deform with the expansion and contraction of the balloon 10, allowing the distal end of the radiofrequency ablation catheter 100 to reach a smaller volume when the balloon 10 contracts, thus reducing the resistance encountered during its intervention in the patient's body.

[0044] The portion of the flexible metal electrode layer 53 located near the wiring area 52 is connected to the radio frequency cable 90 within the wiring cavity 41 to transmit radio frequency current to the flexible metal electrode layer 53 via the radio frequency cable 90. The substrate layer 56 also has conductive vias 561. The distal ends of the first flexible conductor layer 55 and the second flexible conductor layer 57 are connected through the conductive vias 561. The portions of the first flexible conductor layer 55 and the second flexible conductor layer 57 located near the wiring area 52 are respectively connected to the distal ends of the two conductive cables 90 within the wiring cavity 41. The proximal ends of the two conductive cables 90 are connected to a voltage measuring instrument (e.g., a voltmeter) to form a thermocouple circuit. One of the first flexible conductor layer 55 and the second flexible conductor layer 57 corresponds to the positive electrode of the thermocouple, and the other corresponds to the negative electrode. The thermocouple can be any of several types that allow both the positive and negative electrode materials to withstand a certain degree of bending: type K thermocouple, type T thermocouple, type J thermocouple, or type N thermocouple. In this way, the temperature of the target tissue can be transmitted through the portion of the flexible metal electrode layer 53 located in the distal ablation zone 51 to the connection point at the distal end of the first flexible conductor layer 55 and the distal end of the second flexible conductor layer 57. The temperature of this connection point can be detected by utilizing the thermocouple effect, thereby enabling monitoring of the temperature of the radiofrequency ablation area and the target tissue.

[0045] Understandably, the number of RF electrodes 50 is unlimited; there can be one or more. When there is one RF electrode 50, as shown in Figures 2 to 4, the wiring cavity 41 houses one RF cable 90 and two conductive cables 90. When there are multiple RF electrodes 50, the wiring cavity 41 correspondingly houses multiple RF cables 90 and conductive cables 90, one-to-one with each of the multiple RF electrodes 50.

[0046] In some embodiments, the flexible metal electrode layer 53 may further include a coating layer 58 and a back film layer 59. The coating layer 58 is disposed on one side of the flexible metal electrode layer 53 facing away from the liner layer 54. The coating layer 58 has a first window 581 and a second window 582 extending through it. The portion of the flexible metal electrode layer 53 not covered by the coating layer 58 at its distal end is electrically connected to a plating layer 50a deposited in the first window 581. The plating layer 50a is exposed to the surrounding environment to adhere to the target tissue for discharge. The portion of the flexible metal electrode layer 53 not covered by the coating layer 58 at its proximal end is connected to the radio frequency cable 90 through a plating layer 50b deposited in the second window 582. The plating layer 50b and the radio frequency cable 90 may be soldered together, for example. The length of the first window 581 may be, for example, 8 mm and the width may be, for example, 4 mm. Correspondingly, the size of the radio frequency ablation area of ​​the radio frequency electrode 50 is approximately 4 mm × 8 mm. A back film layer 59 is disposed on the side of the second flexible conductor layer 57 facing away from the substrate layer 56. The back film layer 59 has a third window 591 and a fourth window 592 extending through it. The proximal end of the first flexible conductor layer 55 is connected to a conductive cable 90 through a plating layer 50c deposited within the third window 591. The portion of the second flexible conductor layer 57 not covered by the back film layer 59 is connected to another conductive cable 90 through a plating layer 50d deposited within the fourth window 592. Similar to the substrate layer 56 and the liner layer 54, the coating layer 58 and the back film layer 59 are also made of flexible insulating material.

[0047] With each layer of the radiofrequency electrode 50 being flexible, the total thickness of the radiofrequency electrode 50 can be constructed to be less than or equal to 0.2 mm, specifically any value among 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, and 0.2 mm. This design results in a smaller overall thickness of the flexible radiofrequency electrode 50, which allows for a further reduction in the volume of the radiofrequency ablation catheter 100 when inserted into the human body, thereby reducing interventional resistance.

[0048] Figure 6 is a top view of the radiofrequency ablation catheter 100 shown in Figure 1. In some embodiments of this disclosure, as shown in Figure 6, the distal ablation zone 51 facing the balloon 10 may also be provided with a contrasting section 511. During the surgical procedure using the radiofrequency ablation catheter 100 of this embodiment, the contrasting section 511 can be detected using an external imaging detection device (such as an X-ray detection device), making the contrasting section 511 visible. This helps the operator to accurately locate the position of the distal ablation zone 51 of the radiofrequency electrode 50, thereby improving the accuracy and safety of the surgical procedure.

[0049] The material of the imaging section 511 can be selected from one or more materials such as gold, platinum, iridium, tantalum, and tungsten. As an example, the imaging section 511 can be a platinum-iridium alloy imaging section 511, where the mass percentage of platinum in the platinum-iridium alloy is 90% and the mass percentage of iridium is 10%. On the one hand, thanks to the excellent electrical conductivity of the platinum-iridium alloy, it is beneficial to ensure precise control of the current transmitted to the radiofrequency electrode 50. On the other hand, thanks to the good imaging performance of the platinum-iridium alloy, the imaging section 511 is clearly visible during the procedure, facilitating accurate positioning. The thickness of the imaging section 511 can be designed to be greater than or equal to 0.03 mm and less than or equal to 0.07 mm, specifically any value among 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, and 0.07 mm. In this embodiment, the thickness of the imaging section 511 is relatively small, which helps to reduce the volume of the radiofrequency ablation catheter 100 when it is inserted into the human body, thereby reducing interventional resistance.

[0050] The specific implementation of the developing section 511 is diverse. In some embodiments of this disclosure, the developing section 511 can be a closed ring structure, disposed at the edge of the distal ablation zone 51, and the configuration of the developing section 511 is adapted to the configuration of the distal ablation zone 51. For example, if the distal ablation zone 51 is rectangular, then the developing section 511 is a rectangular ring. It should be noted that the rectangle referred to herein is not limited to a right-angled rectangle, but can also be a rounded rectangle or a variation thereof. In other embodiments of this disclosure, the developing section 511 can be constructed as multiple developing points, which are distributed at intervals along the outer periphery of the distal ablation zone 51. For example, in FIG. 6, the number of developing points is 6. Of course, the number of developing points can also be 4, 8, 10, etc., and can be designed according to requirements and actual disclosure. The configuration of the developing points is not limited; for example, they can be circular, rectangular, elliptical, etc. When the developing point is circular, the diameter can be 0.7 mm. This design allows the imaging section 511 to display the approximate outline and boundaries of the radiofrequency electrode 50 in the image, thus revealing the shape of the radiofrequency electrode 50. This enables the operator to more accurately determine the position, orientation, and contact with the target tissue of the radiofrequency electrode 50, thereby further optimizing the treatment effect. Moreover, without changing parameters such as thickness, compared to a technical solution where the imaging section 511 has a closed ring structure, when the imaging section 511 is composed of multiple imaging points, less material is required for the imaging section 511, which helps save material costs.

[0051] In some embodiments of this disclosure, referring further to Figures 2 and 3, the radiofrequency ablation catheter 100 may further include a contrast-enhancing element 31, which is located on the periphery of the distal portion 32 and within the lumen of the balloon 10. During the procedure, the contrast-enhancing element 31 can be detected using an external imaging device, making it visible and thus helping the operator to accurately locate the balloon 10, thereby ensuring that the balloon 10 is accurately positioned at the target tissue location.

[0052] This embodiment does not specifically limit the position and number of the imaging elements 31. According to the embodiments shown in Figures 2 and 3, the balloon 10 may specifically include a proximal conical segment, a cylindrical segment, and a distal conical segment. The distal ablation zone 51 is attached to the outer surface of the cylindrical segment. Two imaging elements 31 are provided, spaced apart along the longitudinal axis of the guidewire 30. One imaging element 31 roughly corresponds to the connection between the cylindrical segment and the distal conical segment, and the other imaging element 31 roughly corresponds to the connection between the cylindrical segment and the proximal conical segment. In this embodiment, the two imaging elements 31 correspond to the proximal and distal ends of the cylindrical segment, respectively. This helps the operator to accurately locate the position of the cylindrical segment, thereby facilitating the determination of the location of the radiofrequency electrode 50 located within the cylindrical segment.

[0053] The total length of the balloon 10 along its longitudinal axis can be greater than or equal to 13 mm and less than or equal to 19 mm. When the balloon 10 includes a proximal conical segment, a cylindrical segment and a distal conical segment, the length of the cylindrical segment can be 9 mm, and the thickness of the balloon 10 can be greater than or equal to 0.01 mm and less than or equal to 0.04 mm.

[0054] The material of the developing element 31 can refer to the material of the developing section 511. Specifically, the material of the developing element 31 can also be selected from one or more of the following materials: gold, platinum, iridium, tantalum, etc.

[0055] Figure 7 is a schematic diagram of the radiofrequency ablation catheter 100 shown in Figure 1. In some embodiments of this disclosure, as shown in Figure 7, the radiofrequency ablation catheter 100 may further include a handle 60, a conduit 70, and a plug 80. The proximal end of the outer sheath 40 is connected to one end of the handle 60, and the other end of the handle 60 is connected to the distal end of the conduit 70. The plug 80 is located at the proximal end of the conduit 70. The cable 90 extends from the proximal end connected to the plug 80 to the distal end connected to the proximal wiring area 52, along the lumen of the conduit 70 to the handle 60, and after passing through the internal channel of the handle 60, extends into the conduit cavity 41. The plug 80 is used to connect the cable 90 to the radiofrequency ablation device, transmitting the high-frequency current generated by the radiofrequency transmitter to the radiofrequency cable 90. In actual use, the operator can conveniently manipulate the radiofrequency ablation catheter 100 for insertion into the human body by holding the handle 60, and can easily adjust the position and direction of the radiofrequency electrode 50, thus enhancing operational convenience.

[0056] The handle 60 also provides a transmission channel for the cable 90, pressurized gas, and guide wire. Exemplarily, referring to Figure 7, the handle 60 may specifically include an upper cover 61, a lower cover 62, and a connecting seat 63. The upper cover 61 and lower cover 62 snap together to form a receiving space, and a portion of the connecting seat 63 is housed within this space. The connecting seat 63 has a first port connected to the inner tube 20, a second port communicating with the guide wire insertion cavity 22, and a side opening communicating with the inflation cavity 21. A Luer connector 64a is connected to the second port for the guide wire to pass through. A Luer connector 64b is connected to the side opening for the introduction of pressurized gas. Luer connectors 64a and 64b are collectively referred to as Luer connectors 64.

[0057] The handle 60 can be made of polyurethane, polyethylene, acrylonitrile-styrene-butadiene copolymer, or a combination thereof. The Luer connector 64 can be made of polycarbonate, polyethylene, acrylonitrile-styrene copolymer, or a combination thereof. Specifically, the Luer connector 64 can be a 6% Luer connector 64, meaning that the length of the Luer connector 64 extending beyond the receiving space of the handle 60 is 6% of the total length of the handle 60.

[0058] As disclosed in this paper, the radiofrequency ablation catheter 100 can have a single-layer or multi-layer structure, with each layer stacked sequentially along the thickness direction of the balloon 10. The balloon 10 can be a non-compliant balloon, and the material of any layer of the balloon 10 can include one or more of the following: polyamide, polyether block polyamide, polyurethane, polyethylene terephthalate, and polyvinyl chloride. In this embodiment, by making the balloon 10 a non-compliant balloon, the balloon 10 can maintain a stable size and volume when the pressure within the balloon's cavity is within a preset range; that is, the size of the balloon 10 can be more precisely controlled. This ensures the stability of the balloon 10's size during treatment, allowing the electrode to stably adhere to the target tissue, thus improving the stability of the treatment effect. Furthermore, the non-compliant balloon does not easily inflate during inflation, thus avoiding over-expansion of the balloon 10 and preventing other damage, reducing the risks during treatment.

[0059] As disclosed in this paper, the inner tube 20 of the radiofrequency ablation catheter 100 can be made of at least one of polyamide, polyether block polyamide, and polyurethane. The outer tube 40 can be a braided tube, and the main body material of the braided tube can be polyamide, polyether block polyamide, polyurethane, or a combination thereof, while the braided filaments can be made of stainless steel. Therefore, the outer tube 40 possesses high strength, good flexibility, and torsion control performance, making it suitable for applications requiring frequent twisting and effectively reducing damage and aging.

[0060] This disclosure also provides a radiofrequency ablation system, including a radiofrequency ablation device and a radiofrequency ablation catheter 100 of any of the foregoing embodiments, wherein the plug 80 of the radiofrequency ablation catheter 100 is connected to the radiofrequency ablation device.

[0061] It should be understood that in this specification, the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship or dimensions based on the orientation or positional relationship or dimensions shown in the accompanying drawings. These terms are used only for ease of description and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this disclosure.

[0062] Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0063] In this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0064] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0065] This specification provides many different implementations or examples that can be used to implement this disclosure. It should be understood that these different implementations or examples are entirely exemplary and are not intended to limit the scope of this disclosure in any way. Those skilled in the art will be able to conceive of various variations or substitutions based on the disclosure of this specification, and these should all be covered within the scope of this disclosure. Therefore, the scope of this disclosure should be determined by the scope defined in the appended claims.

Claims

1. A radiofrequency ablation catheter, comprising: The balloon is inflatable and collapsible, and the proximal end of the balloon is provided with a proximal tube segment extending along its own longitudinal axis. The inner tube has a multi-cavity structure, with an inflation cavity and a guide wire insertion cavity that are not interconnected. The distal end of the inner tube is inserted into the proximal tube segment, and the outer wall of the inner tube is sealed to the inner wall of the proximal tube segment. The distal end of the inflation cavity is connected to the inner cavity of the balloon. A guidewire is inserted into the guidewire insertion cavity, and the distal portion of the guidewire extends from the distal end of the guidewire insertion cavity and extends into the inner cavity of the balloon. The outer wall of the guidewire is sealed to the guidewire insertion cavity. An outer tube is fitted over the inner tube. The distal end of the outer tube is connected to the proximal tube segment, and a gap is formed at the joint. The cable passage cavity between the inner wall of the outer tube and the outer wall of the inner tube is used to accommodate the cable. The radio frequency electrode has a proximal wiring area and a distal ablation area, wherein the proximal wiring area is connected to the cable; From the proximal wiring area to the distal ablation area, the radiofrequency electrode extends along the suture cavity to the slit, and after exiting the slit, extends abutting the surface of the proximal tube segment to the outer surface of the balloon.

2. The radiofrequency ablation catheter according to claim 1, wherein, The radio frequency electrode is bonded to the outer sleeve and the proximal tube section at the gap using sealant, thereby sealing the gap.

3. The radiofrequency ablation catheter according to claim 1 or 2, wherein, The central axis of the inner tube is offset relative to the central axis of the outer tube.

4. The radiofrequency ablation catheter according to claim 3, wherein, Both the inner tube and the outer tube have circular cross-sections, and the eccentricity between the inner tube and the outer tube is close to the difference between the inner diameter and the outer diameter of the outer tube.

5. The radiofrequency ablation catheter according to claim 4, wherein, The central axis of the inflation chamber is further away from the central axis of the outer sleeve than the central axis of the guide wire insertion chamber.

6. The radiofrequency ablation catheter according to any one of claims 1 to 5, wherein, The radio frequency electrode includes at least a flexible metal electrode layer, a liner layer, a first flexible conductor layer, a substrate layer and a second flexible conductor layer, which are stacked sequentially from the outer surface to the inner surface of the balloon. The liner layer and the substrate layer are flexible insulating material layers. The substrate layer is provided with a conductive via. The distal ends of the first flexible conductor layer and the distal ends of the second flexible conductor layer are connected through the conductive via. The portion of the flexible metal electrode layer located in the proximal wiring area is connected to the radio frequency cable in the wiring cavity, and the portions of the first flexible conductor layer and the second flexible conductor layer located in the proximal wiring area are respectively connected to the two conductive cables in the wiring cavity to form a thermocouple circuit.

7. The radiofrequency ablation catheter according to any one of claims 1 to 6, wherein, The distal ablation zone facing the balloon is also provided with a contrasting section.

8. The radiofrequency ablation catheter according to claim 7, wherein, The developing section is a closed ring structure, and the developing section is located at the edge of the distal ablation zone and the configuration of the developing section is adapted to the configuration of the distal ablation zone. Alternatively, the developing section consists of multiple developing points, which are distributed at intervals along the outer periphery of the distal ablation zone.

9. The radiofrequency ablation catheter according to claim 7, wherein, The developing section is a platinum-iridium alloy developing section, wherein the mass percentage of platinum in the platinum-iridium alloy is 90% and the mass percentage of iridium is 10%; and / or, the thickness of the developing section is greater than or equal to 0.03 mm and less than or equal to 0.07 mm.

10. The radiofrequency ablation catheter according to any one of claims 1 to 9, further comprising a contrast-enhancing element disposed on the periphery of the distal portion and located within the lumen of the balloon; and / or, the total thickness of the radiofrequency electrodes is less than or equal to 0.2 mm.

11. The radiofrequency ablation catheter according to any one of claims 1 to 10, further comprising a handle, a conduit, and a plug, wherein the proximal end of the outer sheath is connected to one end of the handle, the other end of the handle is connected to the distal end of the conduit, the plug is disposed at the proximal end of the conduit, and the cable extends from the proximal end connected to the plug to the distal end connected to the proximal wiring area, along the lumen of the conduit to the handle, and after passing through the internal channel of the handle, extends into the conduit cavity.

12. The radiofrequency ablation catheter according to claim 11, wherein, The handle includes an upper cover, a lower cover, and a connecting seat. The upper cover and the lower cover are fastened together to form a receiving space. A portion of the connecting seat is housed within the receiving space. The connecting seat has a first port connected to the inner tube, a second port communicating with the guide wire insertion cavity, and a side port communicating with the inflation cavity. The second port and the side port are each connected to a Luer connector. The Luer connector connected to the second port is used for the guide wire to pass through, and the Luer connector connected to the side port is used for the introduction of pressurized gas.

13. A radiofrequency ablation system, comprising: Radiofrequency ablation device and radiofrequency ablation catheter according to any one of claims 1 to 12.

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