Radio frequency ablation catheter and radio frequency ablation system

Abstract

The utility model provides a radiofrequency ablation catheter and a radiofrequency ablation system. The radiofrequency ablation catheter comprises a balloon, an inner tube, a guide wire tube, an outer sleeve and a radiofrequency electrode, the near end of the balloon is provided with a near-side tube section extending along the longitudinal axis of the balloon; the inner tube is provided with an inflation cavity and a guide wire tube penetrating cavity which are not communicated with each other, the far end of the inner tube is inserted into the near-side tube section, the inner tube is in sealed connection with the near-side tube section, and the far end of the inflation cavity is communicated with an inner cavity of the balloon; the far section part of the guide wire tube extends out of the far end of the guide wire tube penetrating cavity and extends to an inner cavity of the balloon, and the guide wire tube is in sealed connection with the guide wire tube penetrating cavity; the outer sleeve is arranged outside the inner tube in a sleeving mode, the far end of the outer sleeve is connected with the near-side tube section, a gap is formed in the joint, and a threading cavity between the outer sleeve and the inner tube is used for containing a cable; the radio frequency electrode is provided with a far-side ablation area and a near-side wiring area connected with the cable, extends to the gap from the near-side wiring area to the far-side ablation area along the threading cavity, penetrates out of the gap and then is attached to the surface of the near-side pipe section to extend to the outer surface of the balloon.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of medical devices, in particular to a radio frequency ablation catheter and a radio frequency ablation system. BACKGROUND

[0002] Radio frequency ablation technology (RFA) is widely used in the medical field. The working principle of the radio frequency ablation technology is to apply a radio frequency current to a target tissue (such as a tumor or a cardiac lesion). When the radio frequency current flows through the target tissue, the water molecules with polarity in the target tissue move at a high speed due to the rapid change of the electromagnetic field, heat is generated, the water in the cells evaporates and the proteins denature, so as to cause the target tissue to necrose and achieve the treatment purpose. The radio frequency ablation technology is applied in the treatment of many diseases. For example, the radio frequency energy can be used to treat abnormal pathways of electrical signal conduction in the cardiac tissue, so as to restore the normal rhythm of the heart and achieve the purpose of treating arrhythmia. The radio frequency energy can also be used to cause the coagulative necrosis of the tissue to achieve the purpose of removing the tumor. The radio frequency energy can also be used to treat a specific nerve region by generating high temperature to destroy pathological nerve conduction, so as to achieve the purpose of treating chronic pain and neurological diseases.

[0003] At present, a commonly used medical instrument for treatment by using the radio frequency ablation technology is a radio frequency ablation catheter. The distal end of the radio frequency ablation catheter is provided with an electrode made of a metal material. During treatment, the radio frequency ablation catheter is inserted into the patient's body through a natural cavity (such as a blood vessel lumen), the distal end of the radio frequency ablation catheter reaches the target tissue, the electrode is in contact with the target tissue to discharge, and the radio frequency current is conducted to the target tissue along the electrode. However, in actual treatment, the electrode often cannot be fully in contact with the target tissue, which affects the treatment effect. CONTENT OF THE UTILITY MODEL

[0004] The radio frequency ablation catheter and the radio frequency ablation system provided by the embodiments of the present disclosure can be in good contact with the target tissue, so that the treatment effect is improved.

[0005] According to a first aspect of the present disclosure, a radio frequency ablation catheter is provided, comprising: a collapsible 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 segment extending along a longitudinal axis of the balloon; the inner tube is of a multi-cavity structure, and has an inflation cavity and a guide wire tube insertion cavity which are not communicated with each other; a distal end of the inner tube is inserted into the proximal tube segment, and an outer wall of the inner tube is sealingly connected with an inner wall of the proximal tube segment; a distal end of the inflation cavity is communicated with an inner cavity of the balloon; the guide wire tube is arranged in the guide wire tube insertion cavity, and a distal segment of the guide wire tube extends out of a distal end of the guide wire tube insertion cavity and into the inner cavity of the balloon; an outer wall of the guide wire tube is sealingly connected with the guide wire tube insertion cavity; the outer sleeve is arranged outside the inner tube, a distal end of the outer sleeve is connected with the proximal tube segment, and a joint therebetween is formed with a gap; a threading cavity between the inner wall of the outer sleeve and the outer wall of the inner tube is used for accommodating a cable; the radio frequency electrode has a proximal wiring area and a distal ablation area, and the proximal wiring area is connected with the cable; from the proximal wiring area to the distal ablation area, the radio frequency electrode extends along the threading cavity to the gap, and extends along a surface of the proximal tube segment after passing through the gap and then extends to an outer surface of the balloon.

[0006] The radio frequency ablation catheter of the present disclosure has the balloon, the collapsible balloon supports and carries the radio frequency electrode, the balloon in the inflated state can make the radio frequency electrode better adhere to the target tissue, thereby improving the treatment effect. The inner wall of the outer sleeve and the outer wall of the inner tube provide a space for the proximal wiring area of the radio frequency electrode and the cable, so that the connection point of the proximal wiring area and the cable is located in the threading cavity and is not exposed to the surrounding environment, so that the connection point and the tissue are not easily separated or the radio frequency electrode is not easily deviated during the operation of the radio frequency ablation catheter, thereby improving the reliability of the radio frequency ablation catheter.

[0007] In some embodiments, the radio frequency electrode is connected with the outer sleeve and the proximal tube segment by a sealing glue at the gap, so that the gap is blocked.

[0008] In some embodiments, the center axis of the inner tube is eccentrically arranged relative to the center axis of the outer sleeve.

[0009] In some embodiments, the cross sections of the inner tube and the outer sleeve are circular, and the eccentricity of the inner tube and the outer sleeve is close to the difference between the inner diameter of the outer sleeve and the outer diameter of the outer sleeve.

[0010] In some embodiments, the center axis of the inflation cavity is farther away from the center axis of the outer sleeve than the center axis of the guide wire tube insertion cavity.

[0011] In some embodiments, the radiofrequency electrode comprises, from outside to inside of the balloon, a flexible metal electrode layer, a backing layer, a first flexible conductor layer, a substrate layer, and a second flexible conductor layer, the backing layer and the substrate layer are flexible insulating material layers, the substrate layer is provided with a conductive through hole, and a distal end of the first flexible conductor layer and a distal end of the second flexible conductor layer are connected through the conductive through hole; the flexible metal electrode layer is connected with the radiofrequency cable in the threading cavity through the part of the proximal connection area; and the first flexible conductor layer and the second flexible conductor layer are respectively connected with the two conductive cables in the threading cavity to form a thermocouple loop.

[0012] In some embodiments, the distal ablation area is further provided with a developing part on one side of the balloon.

[0013] In some embodiments, the developing part is a closed ring structure, and the developing part is arranged at the edge of the distal ablation area and the configuration of the developing part is matched with the configuration of the distal ablation area; or the developing part is a plurality of developing points, and the plurality of developing points are distributed along the outer periphery of the distal ablation area.

[0014] In some embodiments, the developing part is a platinum-iridium alloy material developing part, and the mass percentage of platinum in the platinum-iridium alloy material is 90%, and the mass percentage of iridium is 10%; and / or the thickness of the developing part is greater than or equal to 0.03 mm and less than or equal to 0.07 mm.

[0015] In some embodiments, the radiofrequency ablation catheter further comprises a developing element arranged on the outer periphery of the distal segment and located in the inner cavity of the balloon; and / or the total thickness of the radiofrequency electrode is less than or equal to 0.2 mm.

[0016] In some embodiments, the radiofrequency ablation catheter further comprises a handle, a threading tube, and a plug, the proximal end of the outer sleeve is connected with one end of the handle, the other end of the handle is connected with the distal end of the threading tube, the plug is arranged at the proximal end of the threading tube, the cable extends along the lumen of the threading tube from the proximal end connected with the plug to the distal end connected with the proximal connection area, and extends to the handle and then extends into the threading cavity through the internal passage of the handle.

[0017] In some embodiments, the handle comprises an upper cover, a lower cover, and a connecting seat, the upper cover and the lower cover are buckled to form an accommodation space, a part of the connecting seat is accommodated in the accommodation space, the connecting seat is provided with a first port connected with the inner tube, a second port connected with the guide wire tube passing cavity, and a side port connected with the inflation cavity, the second port and the side port are respectively connected with a luer connector, the luer connector connected with the second port is used for passing the guide wire, and the luer connector connected with the side port is used for passing the inflation gas.

[0018] According to a second aspect of the present disclosure, a radiofrequency ablation system is provided, comprising a radiofrequency ablation instrument and any one of the radiofrequency ablation catheters provided in the first aspect of the present disclosure.

[0019] 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

[0020] Further details, features, and advantages of this disclosure are disclosed in the following description of exemplary embodiments in conjunction with the accompanying drawings, in which:

[0021] Figure 1 This is a schematic diagram of the structure of radiofrequency ablation catheters according to some embodiments of this disclosure;

[0022] Figure 2 for Figure 1 Schematic diagram of the structure at point A;

[0023] Figure 3 for Figure 2 A schematic cross-sectional view of the radiofrequency ablation catheter shown;

[0024] Figure 4 for Figure 1 A partial structural diagram of the radiofrequency ablation catheter shown;

[0025] Figure 5 This is a schematic diagram of the structure of radio frequency electrodes according to some embodiments of this disclosure;

[0026] Figure 6 for Figure 1 A top view of the radiofrequency ablation catheter shown;

[0027] Figure 7 for Figure 1 The diagram shows the structure of the radiofrequency ablation catheter.

[0028] Explanation of reference numerals in the attached figures:

[0029] 100-Radiofrequency ablation catheter;

[0030] 10-Balloon; 11-Proximal tubular segment; 12-Tip portion;

[0031] 20 - Inner tube; 21 - Inflation chamber; 22 - Guide wire insertion chamber;

[0032] 30-Guide wire cannula; 31-Recognizing element; 32-Distal section;

[0033] 40 - Outer tube; 41 - Threading cavity;

[0034] 50 - radio frequency electrode; 51 - distal ablation zone; 511 - visualization part; 52 - proximal wiring zone; 53 - flexible metal electrode layer; 54 - backing layer; 55 - first flexible conductor layer; 56 - substrate layer; 561 - conductive via; 57 - second flexible conductor layer; 58 - film layer; 581 - first window; 582 - second window; 59 - back film layer; 591 - third window; 592 - fourth window; 50a, 50b, 50c, 50d - plating layer;

[0035] 60 - handle; 61 - upper cover; 62 - lower cover; 63 - connecting seat; 64, 64a, 64b - luer joint;

[0036] 70 - threading tube;

[0037] 80 - plug;

[0038] 90 - cable. DETAILED DESCRIPTION

[0039] Hereinafter, only certain exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present disclosure. Therefore, the drawings and description are considered to be exemplary in nature rather than limiting.

[0040] As used herein, the term "about" or "approximately" with respect to any numerical or digital range indicates suitable dimensional tolerances that allow parts or assemblies to perform their intended purpose as described herein. More specifically, "about" or "approximately" can refer to a range of values ±20% of the recited value, for example, "about 90%" can refer to a range of values from 71% to 99%.

[0041] Additionally, as used herein, the terms "patient," "host," and "user" refer to any human or animal subject and are not intended to limit the systems or methods or uses to human use.

[0042] Figure 1 Structural schematic of a radio frequency ablation catheter for some embodiments of the present disclosure, Figure 2 is Figure 1 Structural schematic at A in the middle, Figure 3 is Figure 2 Cross-sectional schematic of a radio frequency ablation catheter shown in the middle. Please refer to Figures 1 to 3The radio frequency ablation catheter 100 comprises a balloon 10, an inner tube 20, a guide wire tube 30, an outer sleeve tube 40 and a radio frequency electrode 50. The balloon 10 is configured to be inflatable and deflatable, and a proximal tube segment 11 is arranged at a proximal end of the balloon 10 and extends along a longitudinal axis of the balloon 10. The inner tube 20 is a multi-cavity structure, and has an inflation cavity 21 and a guide wire tube passing cavity 22 which are not communicated with each other, the inflation cavity 21 is used for transmitting pressurized gas, a distal end of the inner tube 20 is inserted into the proximal tube segment 11, and an outer wall of the inner tube 20 is sealingly connected with an inner wall of the proximal tube segment 11, and a distal end of the inflation cavity 21 is communicated with an inner cavity of the balloon 10. The guide wire tube 30 is arranged in the guide wire tube passing cavity 22, and a distal segment 32 of the guide wire tube 30 extends out of a distal end of the guide wire tube passing cavity 22 and extends into the inner cavity of the balloon 10, and an outer wall of the guide wire tube 30 is sealingly connected with the guide wire tube passing cavity 22. The outer sleeve tube 40 is arranged outside the inner tube 20, a distal end of the outer sleeve tube 40 is connected with the proximal tube segment 11 and a joint therebetween forms a gap, and a wire passing cavity 41 between an inner wall of the outer sleeve tube 40 and an outer wall of the inner tube 20 is used for accommodating a wire cable (a single "wire cable" or multiple "wire cables" are collectively referred to as "wire cable 90"). The radio frequency electrode 50 has a proximal wiring area 52 and a distal ablation area 51, and the proximal wiring area 52 is connected with the wire cable 90. From the proximal wiring area 52 to the distal ablation area 51, the radio frequency electrode 50 extends along the wire passing cavity 41 to the gap, and extends to an outer surface of the balloon 10 after passing out of the gap and abutting against a surface of the proximal tube segment 11.

[0043] In the embodiments of the present disclosure, taking the balloon 10 as an example, an end of the balloon 10 or a component thereof which is closer to an operator in an extending direction is defined as a "proximal end", and similarly, an end of the balloon 10 or a component thereof which is farther away from the operator in the extending direction is defined as a "distal end". The "proximal end" and the "distal end" of the inner tube 20, the guide wire tube 30, the outer sleeve tube 40 and the like can be defined with reference to the balloon 10, and will not be repeated here. A "side port" is defined as a hole arranged on a side surface of the component, and a "port" is defined as a hole arranged on an end surface of the component.

[0044] As shown in FIG. 1, the radio frequency ablation catheter 100 comprises a balloon 10, an inner tube 20, a guide wire tube 30, an outer sleeve tube 40 and a radio frequency electrode 50. Figure 2 and Figure 3As shown, 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 optional 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 entry, 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.

[0045] 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.

[0046] 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.

[0047] The radio frequency ablation catheter 100 of the embodiments of the present disclosure supports and carries the electrode by setting the balloon 10, and the balloon 10 in the inflated state can make the electrode better adhere to the target tissue, thereby facilitating the improvement of the treatment effect. The embodiments also use the threading cavity 41 between the inner wall of the outer sleeve 40 and the outer wall of the inner tube 20 to provide accommodation space for the proximal wiring area 52 of the radio frequency electrode 50 and the cable 90, so that the connection point of the proximal wiring area 52 and the cable 90 is located in the threading cavity 41 and is not exposed to the surrounding environment, so that the connection point and the tissue are in the same friction during the operation of the radio frequency ablation catheter 100 for treatment. The possibility of disconnection of the proximal wiring area 52 and the cable 90 or the deviation of the radio frequency electrode 50 is small, which is beneficial to improve the reliability of the radio frequency ablation catheter 100. On this basis, by designing the outer wall of the inner tube 20 and the inner wall of the proximal tube segment 11 to be sealingly connected, and the outer wall of the guide wire tube 30 and the guide wire tube penetration cavity 22 to be sealingly connected, the independence between the inflation cavity 21, the guide wire tube penetration cavity 22 and the threading cavity 41 can be improved, so as to reduce the possibility of overflow of the pressurized gas from the gap, so as to ensure the inflation effect of the balloon 10, and thereby make the electrode better adhere to the target tissue.

[0048] In order to further reduce the possibility of overflow of the pressurized gas from the gap, in some embodiments of the present disclosure, the radio frequency electrode 50 at the gap can also be connected by sealing glue and the outer sleeve 40 and the proximal tube segment 11, so that the gap is blocked. The radio frequency ablation catheter 100 of the embodiments can be first assembled and connected with the guide wire tube 30 and the guide wire tube penetration cavity 22 of the inner tube 20, then assembled and connected with the inner tube 20 and the proximal tube segment 11, and then the outer sleeve 40 is sleeved on the outer tube 20, and then the outer sleeve 40 and the proximal tube segment 11 are connected.

[0049] The position matching relationship of the inner tube 20 and the outer sleeve 40 is various. In some embodiments of the present disclosure, the inner tube 20 and the outer sleeve 40 can be coaxially arranged, and the threading cavity 41 formed between the two is annular, and the annular threading cavity 41 has a constant size in the direction perpendicular to the longitudinal axis of the inner tube 20. Figure 4 As an alternative embodiment, as shown in Figure 4 , the center axis of the inner tube 20 can be eccentrically arranged relative to the center axis of the outer sleeve 40, wherein, Figure 1 The radio frequency ablation catheter 100 shown in Figure 4 has a local structure schematic view. By arranging the inner tube 20 and the outer sleeve 40 to be non-coaxial, the size of the threading cavity 41 formed between the two is not constant, and in this example, the maximum value d1 of the size of the threading cavity 41 in the first direction (Y) perpendicular to the longitudinal axis direction of the inner tube 20 max and the maximum value d2 of the size of the threading cavity 41 in the second direction (X) perpendicular to the longitudinal axis direction of the inner tube 20 Figure 4The maximum value d2 of the dimension shown as X max are all larger, wherein the first direction and the second direction are perpendicular to each other. In this way, on the one hand, the cable 90 can be more concentratedly accommodated in the limited space of the threading cavity 41, and on the other hand, the proximal wiring area 52 can be accommodated in the threading cavity 41 with a larger size, so that the size limitation of the proximal wiring area 52 of the radio frequency electrode 50 is relaxed.

[0050] In the case where the central axis of the inner tube 20 is eccentrically arranged relative to the central axis of the outer sleeve 40, further, as shown in Figure 4 , the cross sections of the inner tube 20 and the outer sleeve 40 are both circular, and the eccentricity △D of the inner tube 20 and the outer sleeve 40 is close to the difference between the inner diameter D1 of the outer sleeve 40 and the outer diameter D2 of the inner tube 20. That is, △D is approximately D1-D2. The cross section of the threading cavity 41 in this example is approximately crescent-shaped. In this arrangement, the inner tube 20 is in contact or close contact with the inner wall of the outer sleeve 40, and this design is beneficial to making d1 max and d2 max as large as possible. Of course, in other embodiments of the present disclosure, the cross sections of the inner tube 20 and the outer sleeve 40 can also be optionally one of an elliptical shape, a rectangular shape, an oblong shape, etc. The cross section shapes of the guide wire tube insertion cavity 22 and the inflation cavity 21 in this embodiment are also not limited, and can be, for example, optionally one of a circular shape, a semicircular shape, an elliptical shape, a rectangular shape, an oblong shape, etc. As an example, as shown in Figure 4 , the cross section of the guide wire tube 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.

[0051] In some embodiments of the present disclosure, the central axis of the inflation cavity 21 can be configured to be farther away from the central axis of the outer sleeve 40 than the central axis of the guide wire tube insertion cavity 22. In this way, in Figure 4 , the inflation cavity 21 is located below the guide wire tube insertion cavity 22. Compared with the guide wire tube insertion cavity 22 being located below the inflation cavity 21, this design of the present embodiment can make the center of gravity of the guide wire tube 30 arranged in the guide wire tube insertion cavity 22 not deviate too much from the center of the outer sleeve 40, so that the center of gravity of the balloon 10 coaxially arranged with the distal segment portion 32 also does not deviate too much from the center of the outer sleeve 40, which is beneficial to making the radio frequency ablation catheter 100 have good balance and reliability.

[0052] Figure 5 Structure schematic diagram of the radio frequency electrode 50 of some embodiments of the present disclosure. In some embodiments of the present disclosure, as shown in Figure 5As shown, the radio frequency electrode 50 can at least include, from the outer surface of the balloon 10 to the inner surface, a flexible metal electrode layer 53, a backing layer 54, a first flexible conductor layer 55, a substrate layer 56 and a second flexible conductor layer 57, the backing layer 54 and the substrate layer 56 are layers of flexible insulating material. The flexible insulating material can be polyimide (PI), polyethylene terephthalate (PET), polyurethane (PU) or a combination thereof. As can be seen, each layer of the radio frequency electrode 50 of the present embodiment is flexible, and the radio frequency electrode 50 as a whole has good flexibility, and the radio frequency electrode 50 can deform with the expansion and contraction of the balloon 10, so that the distal end of the radio frequency ablation catheter 100 can reach a smaller volume when the balloon 10 is contracted, which is beneficial to reducing the resistance of the radio frequency ablation catheter 100 during its interventional process in the patient's body.

[0053] The flexible metal electrode layer 53 is connected to the radio frequency cable 90 in the threading cavity 41 at the portion of the proximal wiring area 52, so as to transmit radio frequency current to the flexible metal electrode layer 53 through the radio frequency cable 90. The substrate layer 56 is also provided with a conductive through hole 561, and the distal end of the first flexible conductor layer 55 and the distal end of the second flexible conductor layer 57 are connected through the conductive through hole 561. The first flexible conductor layer 55 and the second flexible conductor layer 57 are connected to the distal ends of the two conductive cables 90 in the threading cavity 41 at the portion of the proximal wiring area 52, and the proximal ends of the two conductive cables 90 are connected to a voltage measuring instrument (such as a voltmeter), so as to form a thermocouple loop. Among them, 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 of the thermocouple. The thermocouple here can be any one of several types that meet the requirements that both the positive electrode material and the negative electrode material can withstand a certain bending: K-type thermocouple, T-type thermocouple, J-type thermocouple, N-type thermocouple. In this way, the temperature of the target tissue can be transmitted to the connection point of the distal end of the first flexible conductor layer 55 and the distal end of the second flexible conductor layer 57 through the portion of the flexible metal electrode layer 53 located in the distal ablation area 51. By utilizing the thermoelectric effect, the temperature of the connection point can be detected, so as to realize the monitoring of the temperature of the radio frequency ablation area and the target tissue.

[0054] As can be understood, the number of radio frequency electrodes 50 is not limited, and can be one or multiple. When the radio frequency electrode 50 is one, as shown in FIG. 1, the threading cavity 41 contains one radio frequency cable 90 and two conductive cables 90. Figures 2 to 4 When the radio frequency electrode 50 is multiple, correspondingly, the threading cavity 41 contains multiple radio frequency cables 90 and conductive cables 90 corresponding to the multiple radio frequency electrodes 50.

[0055] 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 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 the 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.

[0056] 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.

[0057] Figure 6 for Figure 1 The diagram shows a top view of the radiofrequency ablation catheter 100. In some embodiments of this disclosure, such as... Figure 6 As shown, the distal ablation zone 51 facing the balloon 10 may also be provided with a contrasting section 511. During the procedure using the radiofrequency ablation catheter 100 of this embodiment, the contrasting section 511 can be detected using an external imaging 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 procedure.

[0058] 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.

[0059] The specific implementation of the developing section 511 is varied. In some embodiments of this disclosure, the developing section 511 can be a closed ring structure, disposed at the edge of the distal ablation region 51, and the configuration of the developing section 511 is adapted to the configuration of the distal ablation region 51. For example, if the distal ablation region 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 configured as multiple developing points, which are distributed at intervals along the outer periphery of the distal ablation region 51. For example, in Figure 6 In this design, there are 6 imaging points, but the number can also be 4, 8, 10, etc., depending on the specific requirements and available information. The shape of the imaging points is not limited; for example, they can be circular, rectangular, or elliptical. When the imaging points are circular, the diameter can be 0.7 mm. This design allows the imaging section 511 to display the approximate outline and boundary of the radiofrequency electrode 50 in the image, thus showing the shape of the radiofrequency electrode 50. This allows 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 with a closed-ring structure, when the imaging section 511 is composed of multiple imaging points, the imaging section 511 requires less material, which helps save material costs.

[0060] In some embodiments of this disclosure, please continue to refer to Figure 2 and Figure 3The radiofrequency ablation catheter 100 can further comprise a visualization element 31 arranged on the outer circumference of the distal section 32 and located in the inner lumen of the balloon 10. During the operation, the visualization element 31 can be detected by an external image detection device so that the visualization element 31 can be visualized, thereby helping the operator to accurately position the balloon 10, and thereby ensuring that the balloon 10 is accurately positioned at the location of the target tissue.

[0061] The embodiments of the present disclosure do not specifically limit the position and number of the visualization element 31. According to the embodiments shown in Figure 2 and Figure 3 The balloon 10 can specifically comprise a proximal conical section, a cylindrical section and a distal conical section, the distal ablation zone 51 is attached to the outer surface of the cylindrical section, and the visualization element 31 is provided with two, the two visualization elements 31 are arranged in the longitudinal axis direction of the guide wire tube 30, one of the visualization elements 31 corresponds to the connection between the cylindrical section and the distal conical section, and the other visualization element 31 corresponds to the connection between the cylindrical section and the proximal conical section. The embodiments of the present disclosure make the two visualization elements 31 correspond to the proximal end and the distal end of the cylindrical section respectively, which is beneficial to help the operator to accurately position the cylindrical section, and thereby the position of the radiofrequency electrode 50 located in the cylindrical section can be easily known.

[0062] The total length of the balloon 10 along its longitudinal axis direction can be greater than or equal to 13 mm and less than or equal to 19 mm. In the case where the balloon 10 comprises a proximal conical section, a cylindrical section and a distal conical section, the length of the cylindrical section can be specifically 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.

[0063] The material of the visualization element 31 can refer to the material of the visualization part 511. Specifically, the material of the visualization element 31 can also be selected from one or more of gold, platinum, iridium, tantalum and the like.

[0064] Figure 7 The radiofrequency ablation catheter 100 shown in Figure 1 The structure schematic diagram of the radiofrequency ablation catheter 100 shown in the present disclosure. In some embodiments of the present disclosure, as Figure 7As shown, the radio frequency ablation catheter 100 can further include a handle 60, a wire tube 70, and a plug 80. The proximal end of the outer sleeve 40 is connected to one end of the handle 60, the other end of the handle 60 is connected to the distal end of the wire tube 70, and the plug 80 is arranged at the proximal end of the wire tube 70. The cable 90 extends along the lumen of the wire tube 70 from the proximal end connected to the plug 80 to the distal end connected to the proximal wiring area 52, and extends into the handle 60 and then into the wire lumen 41 through the internal passage of the handle 60. The plug 80 is used to connect the cable 90 to the radio frequency ablation instrument to transmit the high-frequency current generated by the radio frequency capable transmitter to the radio frequency cable 90. In actual use, the operator can conveniently control the radio frequency ablation catheter 100 to intervene in the human body by holding the handle 60, and can conveniently adjust the position and direction of the radio frequency electrode 50, and the operation convenience is enhanced.

[0065] The handle 60 also provides a transmission channel for the cable 90, the pressurized gas, and the guide wire. For example, referring to Figure 7 , the handle 60 can specifically include an upper cover 61, a lower cover 62, and a connecting seat 63. The upper cover 61 and the lower cover 62 are buckled to form an accommodation space, and part of the connecting seat 63 is accommodated in the accommodation space. The connecting seat 63 has a first port connected to the inner tube 20, a second port connected to the guide wire tube insertion lumen 22, and a side port connected to the inflation lumen 21. The second port is connected to a luer connector 64a for the guide wire to pass through. The side port is connected to a luer connector 64b for the pressurized gas to pass through. The luer connector 64a and the luer connector 64b are collectively referred to as the luer connector 64.

[0066] The material of the handle 60 can be polyurethane, polyethylene, acrylonitrile-styrene-diene copolymer, or a combination thereof. The material of the luer connector 64 can be polycarbonate, polyethylene, acrylonitrile-styrene copolymer, or a combination thereof. The luer connector 64 can specifically be a 6% luer connector 64, which specifically refers to the length of the luer connector 64 extending out of the accommodation space of the handle 60 being 6% of the total length of the handle 60.

[0067] The balloon 10 can be a single-layer structure or a multi-layer structure, and each layer is arranged in sequence 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 polyamide, polyether block polyamide, polyurethane, polyethylene terephthalate, polyvinyl chloride, and the like. 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 in the balloon 10 lumen is within a predetermined range, that is, the size of the balloon 10 can be more accurately controlled. In this way, the size of the balloon 10 is stable during treatment, so that the electrode can be stably attached to the target tissue, thereby improving the stability of the treatment effect. Moreover, the non-compliant balloon will not easily expand when inflated, so that excessive expansion of the balloon 10 can be avoided to cause other damage, thereby reducing the risk during treatment.

[0068] The material of the inner tube 20 can be at least one of polyamide, polyether block polyamide, and polyurethane. The outer sleeve 40 can be a braided tube, and the main material of the braided tube can be polyamide, polyether block polyamide, polyurethane, or a combination thereof, and the material of the braided wire of the braided tube can be stainless steel. In this way, the outer sleeve 40 has high strength, good flexibility, and twist control performance, so that the outer sleeve 40 can be suitable for applications that are allowed to be frequently twisted, and can effectively reduce damage and aging.

[0069] The embodiments of the present disclosure also provide a radio frequency ablation system, which includes a radio frequency ablation instrument and the radio frequency ablation catheter 100 of any of the preceding embodiments, and the plug 80 of the radio frequency ablation catheter 100 is connected to the radio frequency ablation instrument.

[0070] 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", "circumferential", and the like indicate the orientation or positional relationship or size based on the orientation or positional relationship or size shown in the drawings, and the use of these terms is only for the convenience of description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the present disclosure.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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, characterized in that, include: 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, characterized in that, 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, characterized in that, 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, characterized in that, 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, characterized in that, 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 claim 1, characterized in that, 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 claim 1, characterized in that, The distal ablation zone facing the balloon is also provided with a contrasting section.

8. The radiofrequency ablation catheter according to claim 7, characterized in that, 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, characterized in that, 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, characterized in that, It also includes a imaging element disposed on the periphery of the distal portion and located within the cavity of the balloon; and / or, the total thickness of the radiofrequency electrode is less than or equal to 0.2 mm.

11. The radiofrequency ablation catheter according to any one of claims 1 to 9, characterized in that, It also 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.

12. The radiofrequency ablation catheter according to claim 11, characterized in that, 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, characterized in that, include: Radiofrequency ablation device and radiofrequency ablation catheter according to any one of claims 1 to 12.

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