Ablation catheter and working method thereof

Abstract

The invention belongs to the technical field of ablation instruments, and particularly relates to an ablation catheter and a working method thereof.The ablation catheter comprises an outer catheter body, a middle catheter body and an inner catheter body which are sequentially and coaxially arranged from outside to inside, the outer catheter body and the middle catheter body are in clearance fit, and the middle catheter body and the inner catheter body are in clearance fit; an electrode carrier is assembled at one end of the outer side of the outer catheter, an ablation electrode is arranged on the outer side of the electrode carrier, a handle is assembled at the other end of the outer catheter, and the handle is rotationally connected with the middle catheter. The unfolding angle of the supporting arm is adjusted by operating the driving key, so that the outer diameter of the electrode carrier is adjusted to adapt to patients with different duodenum inner diameters, meanwhile, the rotating angle of the supporting arm is adjusted, the form of the electrode carrier can be changed, the device can ablate all parts and the ball part of the duodenum, the application range is expanded, and the working efficiency is improved. And local excessive ablation or incomplete ablation caused by non-uniform pressure when the electrode carrier and the ablation electrode are in contact with the inner wall of the ball part is prevented.

Description

Technical Field

[0001] The present invention belongs to the technical field of ablation devices, and particularly relates to an ablation catheter and its working method. Background Art

[0002] Diabetes is a globally prevalent chronic metabolic disease, among which type 2 diabetes accounts for 90% - 95%. Traditional treatment methods such as drugs and insulin injection are difficult to meet the blood glucose control needs of all patients. In recent years, due to the key role of the duodenum in glucose metabolism regulation, an innovative solution of applying radiofrequency ablation technology to specific areas of the duodenum for diabetes treatment has attracted much attention. This technology regulates the neuroendocrine system by ablating the inner wall of the duodenum and improves insulin sensitivity, opening up a new path for diabetes treatment. As the core tool for energy transfer and tissue ablation, the structural design of the ablation catheter directly affects the treatment effect.

[0003] However, the current catheter technology for ablating the inner wall of the duodenum has many limitations:

[0004] Firstly, most existing ablation electrodes are cylindrical or conventional ring-shaped structures, which have a significant adaptation contradiction with the special shape of the duodenum. The duodenal bulb (i.e., the upper part) is in the shape of a frustum of a cone, about 5 cm long, with an inner diameter of 3 - 5 cm. When a cylindrical electrode extends, it forms a regular column. When ablating the inner wall of the bulb, conventional cylindrical or ring-shaped ablation electrodes will cause local dilation of the bulb. Due to the uneven contact pressure between the ablation electrode and each point on the inner wall, it is easy to cause local over-ablation and damage the normal physiological structure of the intestine.

[0005] Secondly, at the curved parts of the duodenum such as the upper flexure, lower flexure, and jejunal flexure, the inner wall presents an asymmetric shape, and the length of the inner bend is significantly smaller than that of the outer bend (the duodenum is a tissue with a certain width. In the vertical projection plane, the side with the smallest radius is recorded as the inner bend, and the side with the largest radius is recorded as the outer bend. Its shape can be approximated by two concentric arcs with different radii). After the cylindrical ablation electrode is bent, the material of the outer bend part of the ablation electrode will undergo non-uniform deformation, making the cross-section of the outer bend of the ablation electrode elliptical. Moreover, the greater the bending degree of the ablation electrode, the more obvious the ellipticity of the cross-section of the outer bend of the ablation electrode. This results in a gap between the outer bend part of the ablation electrode and the outer bend part of the curved part of the duodenum, and they cannot be completely and tightly fitted. Not only can it not perform a complete circumferential ablation on the curved part, but it may also affect the ablation effect due to insufficient local electric field intensity, and even multiple repeated operations may be required, increasing the trauma risk to the patient.

[0006] Thirdly, there are operational difficulties in the electrode assembly of existing ablation catheters during the deployment and retraction processes. For example, it is difficult to control the degree of expansion of the annular electrode, the strip-shaped ball cage electrode is prone to accidental contact, the mesh ball cage electrode is prone to tissue damage or operational obstruction during release and retraction, and the ablation assembly does not match the shape of the lesion area, resulting in poor apposition effect and insufficient electric field strength, forcing doctors to repeatedly adjust the angle, significantly increasing the surgical operation difficulty, duration, and risk.

[0007] In summary, existing ablation catheters are difficult to meet the clinical needs of radiofrequency ablation of the duodenum for diabetes treatment in terms of structural design and function implementation. There is an urgent need to develop a new ablation catheter structure to optimize the morphological adaptability and operational stability of the ablation assembly, improve the coverage efficiency of the lesion area, reduce the complexity of surgical operations, and thus promote the clinical application and development of the technology of radiofrequency ablation of the duodenum for diabetes treatment. Summary of the Invention

[0008] The object of the present invention is to provide an ablation catheter. By operating the driving key to adjust the deployment angle of the support arm, the outer diameter of the electrode carrier can be adjusted to adapt to patients with different duodenal inner diameters. At the same time, by adjusting the rotation angle of the support arm, the shape of the electrode carrier can be changed, enabling the device to ablate various parts and the bulb of the duodenum, expanding the scope of application, and preventing uneven pressure when the electrode carrier and the ablation electrode contact the inner wall of the bulb, resulting in local over-ablation or incomplete ablation.

[0009] The technical solutions adopted by the present invention are specifically as follows:

[0010] An ablation catheter includes an outer catheter, a middle catheter, and an inner catheter coaxially arranged from outside to inside in sequence. There is a clearance fit between the outer catheter and the middle catheter, and between the middle catheter and the inner catheter. One end of the outer catheter is equipped with an electrode carrier on the outside, and ablation electrodes are arranged on the outside of the electrode carrier. The other end of the outer catheter is equipped with a handle, and the handle is rotatably connected to the middle catheter. It further includes:

[0011] Two support parts, both of the two support parts are assembled on the outside of the middle catheter. The support part includes a first support bushing, a second support bushing, a plurality of swing arms, and a plurality of support arms. The first support bushing is rotatably connected to the outside of the middle catheter. The second support bushing in one support part is fixed to the outside of the inner catheter, and the second support bushing in the other support part is fixed to the outside of the outer catheter. A plurality of the swing arms are rotatably connected inside the side wall of the first support bushing, and a plurality of the support arms are rotatably connected inside the side wall of the second support bushing. The swing arms and the support arms are slidably connected;

[0012] Two telescopic driving parts, both of the two telescopic driving parts are assembled inside the handle, and the outer catheter and the telescopic driving part, as well as the inner catheter and the telescopic driving part, are adapted to each other one by one. The two telescopic driving parts are configured to be able to drive the outer catheter or the inner catheter to move respectively;

[0013] Wherein, after operating the two telescopic driving parts respectively, the electrode carrier and the support part are switched between the extended state and the contracted state. In the extended state, the cross-sectional shape of the electrode carrier is one of the following shapes: trapezoid, rectangle.

[0014] In a preferred embodiment, an annular groove is formed on the outer side of the middle catheter, an annular boss is arranged inside the first support bushing, and the annular groove and the annular boss are adapted to each other.

[0015] In a preferred embodiment, a guide ring is fixed to one end of the support arm away from the second support bushing. An expansion ring is slidably connected inside the plurality of guide rings. Hemispherical ends and anti-detachment rings are respectively fixed to both ends of the expansion ring, and the expansion ring and the anti-detachment ring, as well as the hemispherical end and the anti-detachment ring, are all adapted to each other. Among them, when the support part is in the extended state, the expansion ring is in a circular ring form, and when the support part is in the contracted state, the expansion ring is in a spiral form.

[0016] In a preferred embodiment, the diameter of the hemispherical end is larger than the inner diameter of the anti-detachment ring.

[0017] In a preferred embodiment, two guide through grooves are formed on the outer side of the handle. The telescopic driving part includes a guide rod, a driving key and an elastic element. Among them, the guide rod in one telescopic driving part is fixed to one end of the outer side of the outer catheter away from the electrode carrier, and the guide rod in the other telescopic driving part is fixed to one end of the outer side of the inner catheter away from the electrode carrier. The driving key is slidably connected to the upper end inside the guide rod. The driving key is adapted to the guide through groove, and the upper end of the driving key penetrates through the inside of the guide through groove and extends to the outside of the handle. The elastic element is assembled between the guide rod and the driving key. Among them, the elastic element is always in a compressed state.

[0018] In a preferred embodiment, a plurality of limiting teeth are evenly arranged on both sides of the upper end of the driving key, and a plurality of stopping teeth are arranged on the inner wall of the handle, and the limiting teeth and the stopping teeth are adapted to each other.

[0019] In a preferred embodiment, an inner support assembly is assembled on the outer side of the middle catheter and between two support portions. The inner support assembly includes a fixed collar, a movable collar, and an inner support frame. The fixed collar is rotatably connected to the outer side of the middle catheter. The movable collar is fixed to the outer side of the middle catheter. The inner support frame is assembled between the fixed collar and the movable collar. Among them, the first support bushing in the support portion connected to the inner catheter is fixedly connected to the fixed collar.

[0020] In a preferred embodiment, an inner support driving portion is assembled inside the handle. The inner support driving portion includes a driven gear and a driving handle. The driven gear is fixed to the outer side of the middle catheter and inside the handle. The driving handle is rotatably connected to the inside of the driven gear. One end of the driving handle is provided with a driving gear, and the driving gear is meshed with the driven gear.

[0021] In a preferred embodiment, an ablation catheter applicable to any one of the above includes the following steps:

[0022] Stp1: Drive the two telescopic driving portions to operate respectively, and drive the outer catheter and the inner catheter to move towards each other through the two driving keys.

[0023] Stp2: Drive the two support portions to operate through the outer catheter and the inner catheter respectively, so that the support portions drive the electrode carrier to change from the contracted state to the extended state synchronously until the electrode carrier reaches the expected shape. Among them, if the moving distances of the outer catheter and the inner catheter are the same, the cross-sectional shape of the electrode carrier is rectangular; if the moving distances of the outer catheter and the inner catheter are different, the cross-sectional shape of the electrode carrier is trapezoidal.

[0024] Stp3: Rotate the driving handle, drive the middle catheter and the movable collar to rotate through the driving handle, drive the inner support frame to expand radially in a spiral manner through the movable collar, and make the inner support frame support the inner wall of the electrode carrier.

[0025] The technical effects achieved by the present invention are:

[0026] In the present invention, two telescopic driving parts drive the outer catheter and the inner catheter to move respectively, so that the supporting part and the electrode carrier can be synchronously transformed from the contracted state to the extended state. When the rotation angles of the support arms in the two supporting parts are different, the cross-sectional shape of the electrode carrier is trapezoidal. Through the cooperation of the electrode carrier and the ablation electrode, the conical frustum-shaped bulb in the duodenum can be ablated; when the rotation angles of the support arms in the two supporting parts are the same, the cross-sectional shape of the electrode carrier is rectangular. Through the cooperation of the electrode carrier and the ablation electrode, the ascending part, descending part and horizontal part in the duodenum can be ablated, enabling the device to adjust the shape of the electrode carrier according to the shape of the ablation site, avoiding uneven contact pressure at each point on the inner wall of the bulb caused by the contact between the electrode carrier, the ablation electrode and the inner wall of the bulb, resulting in over-ablation or incomplete ablation, and thus avoiding damage to the normal physiological structure of the intestine;

[0027] In the present invention, by synchronously adjusting the moving distances of the outer catheter and the inner catheter to control the rotation angle of the support arm, the outer diameter of the extended electrode carrier can be adjusted, enabling the device to be applicable to patients with different duodenal inner diameters, such as adult and pediatric patients, and avoiding the risk of mechanical damage to the duodenal wall tissue and physiological function disorders caused by excessive dilation of the duodenal inner diameter by the extended electrode carrier;

[0028] In the present invention, by rotating the driving handle to drive the middle catheter and the movable collar to rotate, and driving the inner support frame to perform spiral radial expansion through the movable collar, the inner support frame supports and expands the inner wall of the electrode carrier to a certain extent until the electrode carrier fits the outer bend of the curved part of the duodenum. When the device ablates the curved part of the duodenum, the electrode carrier and the ablation electrode can fit the outer bend of the curved part, enabling the outer bend of the curved part to achieve complete circumferential ablation, without the need for medical staff to repeatedly operate and adjust the angle, reducing the surgical operation difficulty, duration and trauma risk. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is the overall structural schematic diagram of the present invention;

[0030] Figure 2 is the internal structural schematic diagram of the electrode carrier of the present invention;

[0031] Figure 3 is the internal structural sectional view of the electrode carrier of the present invention;

[0032] Figure 4 is the structural schematic diagram of the supporting part in the extended state of the present invention;

[0033] Figure 5 is the structural schematic diagram of the middle catheter and the first support bushing of the present invention;

[0034] Figure 6is the present invention Figure 4 The partial enlarged schematic view of the position A in the present invention;

[0035] Figure 7 is the schematic structural view of the inside of the handle of the present invention;

[0036] Figure 8 is the present invention Figure 7 The partial enlarged schematic view of the position B in the present invention;

[0037] Figure 9 is the sectional view of the structure inside the handle of the present invention;

[0038] Figure 10 is the schematic structural view of the telescopic driving part of the present invention;

[0039] Figure 11 is the schematic structural view of the inner support assembly of the present invention;

[0040] Figure 12 is the exploded schematic view of the structure of the inner support assembly of the present invention;

[0041] Figure 13 is the schematic structural view of the device in the contracted state of the present invention;

[0042] Figure 14 is the schematic structural view of the support part in the contracted state of the present invention.

[0043] In the drawings, the list of components represented by each reference numeral is as follows:

[0044] 10. Outer catheter; 11. Middle catheter; 12. Inner catheter; 13. Electrode carrier; 14. Ablation electrode; 15. Handle; 16. Annular groove; 17. Guide groove; 18. Stopping tooth;

[0045] 20. Support part;

[0046] 21. First support bushing; 22. Second support bushing; 23. Swing arm; 24. Support arm; 25. Annular boss; 26. Guide ring; 27. Expansion ring; 28. Hemispherical end; 29. Anti-disengagement ring;

[0047] 30. Telescopic driving part;

[0048] 31. Guide rod; 32. Driving key; 33. Elastic element; 34. Limiting tooth;

[0049] 40. Inner support assembly;

[0050] 41. Fixed collar; 42. Movable collar; 43. Inner support framework;

[0051] 50. Inner support driving part;

[0052] 51. Driven gear; 52. Driving handle. Detailed implementation manners

[0053] To make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific implementation manners of the present invention will be given with reference to the accompanying drawings of the specification.

[0054] In the following description, many specific details are set forth to facilitate a thorough understanding of the present invention. However, the present invention may be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0055] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure or characteristic that may be included in at least one implementation manner of the present invention. The appearances of "in a preferred embodiment" in different places in this specification do not all refer to the same embodiment, nor are they separate or selectively exclusive embodiments from other embodiments.

[0056] Thirdly, the present invention will be described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for the convenience of explanation, the cross-sectional views showing the device structure will be enlarged locally out of the general scale, and the schematic diagrams are only examples and should not limit the scope of protection of the present invention herein. In addition, in actual production, three-dimensional spatial dimensions including length, width and depth should be included.

[0057] Embodiment 1

[0058] Please refer to the attached Figures 1 to 4 As shown, this is the first embodiment of the present invention. This embodiment provides an ablation catheter, which includes an outer catheter 10, a middle catheter 11 and an inner catheter 12 coaxially arranged from outside to inside in sequence. There is a clearance fit between the outer catheter 10 and the middle catheter 11, and between the middle catheter 11 and the inner catheter 12. Both ends of the middle catheter 11 extend to the outside of the outer catheter 10, and both ends of the inner catheter 12 extend to the outside of the middle catheter 11. One end on the outside of the outer catheter 10 is equipped with an electrode carrier 13, and an ablation electrode 14 is arranged on the outside of the electrode carrier 13. The other end of the outer catheter 10 is equipped with a handle 15, and the handle 15 is rotatably connected to the middle catheter 11. It further includes:

[0059] Two support parts 20, both of the two support parts 20 are assembled on the outer side of the middle catheter 11. Among them, one support part 20 is assembled between the outer catheter 10 and the middle catheter 11, and the other support part 20 is assembled between the middle catheter 11 and the inner catheter 12, and the installation directions of the two support parts 20 are opposite. The support part 20 includes a first support bushing 21, a second support bushing 22, a plurality of swing arms 23 and a plurality of support arms 24. The first support bushing 21 is rotatably connected to the outer side of the middle catheter 11. The second support bushing 22 in one support part 20 is fixed to the outer side of the inner catheter 12, and the second support bushing 22 in the other support part 20 is fixed to the outer side of the outer catheter 10, and the first support bushing 21 and the second support bushing 22 in the same support part 20 are adapted to each other. The two ends of the electrode carrier 13 are respectively fixed to the ends of the two second support bushings 22 away from each other by bonding. A plurality of swing arms 23 are all rotatably connected to the inside of the side wall of the first support bushing 21, and a plurality of swing arms 23 are annularly distributed on the outer side of the first support bushing 21. A plurality of support arms 24 are all rotatably connected to the inside of the side wall of the second support bushing 22, and a plurality of support arms 24 are annularly arrayed on the outer side of the second support bushing 22. A plurality of swing arms 23 and a plurality of support arms 24 correspond to each other one by one, and the corresponding swing arms 23 and support arms 24 are slidably connected;

[0060] Two telescopic drive parts 30, both of the two telescopic drive parts 30 are assembled inside the handle 15, and the outer catheter 10 and the telescopic drive part 30, and the inner catheter 12 and the telescopic drive part 30 are adapted to each other one by one. The two telescopic drive parts 30 are configured to be able to drive the outer catheter 10 or the inner catheter 12 to move respectively;

[0061] An inner support assembly 40, the inner support assembly 40 is assembled on the outer side of the middle catheter 11 and is located between the two support parts 20, and the inner support assembly 40 is adapted to the electrode carrier 13;

[0062] An inner support drive part 50, the inner support drive part 50 is assembled inside the handle 15, and the inner support drive part 50 is connected to the middle catheter 11, and the inner support drive part 50 can drive the middle catheter 11 to rotate around its own central axis;

[0063] Among them, after the two telescopic drive parts 30 are respectively operated, the electrode carrier 13 and the support part 20 can be switched between the extended state and the contracted state. In the extended state, the cross-sectional shape of the electrode carrier 13 is one of the following shapes: trapezoid, rectangle.

[0064] Specifically, before ablating the target tissue, the device is in the contracted state, and when ablating the target tissue, the device is in the extended state.

[0065] It should be noted that the structural form of the ablation electrode 14 is any one of the following forms: interdigital ablation electrode, logarithmic spiral ablation electrode, Archimedean spiral ablation electrode, hyperbolic spiral ablation electrode, square spiral ablation electrode or other spiral electrode forms. Its specific structural form can be selected and adjusted according to actual clinical needs. Here, it does not constitute a specific limitation. In this embodiment, the structural form of the ablation electrode 14 is an interdigital ablation electrode, and the ablation electrode 14 is arranged on the surface of the electrode carrier 13 by means of a flexible circuit process using conductive silver paste when the electrode carrier 13 is in a stretched state. And the flexible circuit process is an existing mature application. Here, no further elaboration is made. Specifically, the material of the electrode carrier 13 is a flexible material with stretchable characteristics.

[0066] Furthermore, a plurality of temperature sensors (not shown in the figure) are fixed on the surface of the electrode carrier 13. An ablation instrument and an imaging device are also used in conjunction with this device. The temperature sensor can monitor the temperature of the target tissue to be ablated. The ablation instrument can send current to the ablation electrode 14 so that the ablation electrode 14 ablates the target tissue. The imaging device can acquire an image of the target tissue and guide the electrode carrier 13 to reach the target position. A wire channel is provided inside the outer catheter 10, and a wire is radiated inside the wire channel. The ablation electrode 14, the ablation instrument, the temperature sensor and the ablation instrument are all electrically connected through the wire. Among them, both the temperature sensor and the ablation instrument are existing mature applications. Its form can be any one of thermocouples or thermistors. Its working principle can refer to the prior art. Here, no further elaboration is made.

[0067] Specifically, a clamping plate is integrally formed inside the handle 15. An annular clamping groove is provided at one end of the outer side of the middle catheter 11 away from the electrode carrier 13. The clamping plate and the annular clamping groove are adapted to each other. The handle 15 and the middle catheter 11 are rotationally connected through the cooperation of the clamping plate and the annular clamping groove. Furthermore, the handle 15 is also equipped with other ablation supporting accessory elements. The supporting accessory elements can be adaptively adjusted according to actual clinical needs and existing conventional technologies. Here, no further elaboration is made.

[0068] In this embodiment, when ablating the inner wall of the duodenum, the electrode carrier 13 is placed inside the duodenum. Under the guidance of an imaging device, the device is delivered to the target position. The outer catheter 10 and the inner catheter 12 are respectively driven by two telescopic driving parts 30 to move towards each other. Through the cooperation of the middle catheter 11 and the inner catheter 12, the two second support bushings 22 move towards the first support bushing 21. Through the cooperation of the second support bushing 22 and the swing arm 23, while the second support bushing 22 moves, the support arm 24 rotates relative to the second support bushing 22, so that the support part 20 changes from the contracted state to the extended state. The contracted electrode carrier 13 is supported by multiple support arms 24, so that the electrode carrier 13 synchronously changes from the contracted state to the extended state until the electrode carrier 13 and the inner wall, and the ablation electrode 14 and the inner wall are in mutual contact. The ablation instrument is started, and the inner wall of the duodenum is ablated by the ablation electrode 14. The ablation is repeated multiple times until the entire section of the inner wall of the duodenum is completely ablated. During the above ablation process, if the moving distances of the middle catheter 11 and the inner catheter 12 relative to the outer catheter 10 are the same, the rotation angles of the support arms 24 in the two support parts 20 are the same. At this time, the cross-sectional shape of the electrode carrier 13 in the extended state is rectangular. The horizontal part, ascending part and descending part in the duodenum can be ablated by the ablation electrode 14. At the same time, by synchronously adjusting the moving distances of the outer catheter 10 and the inner catheter 12 and controlling the rotation angle of the support arm 24, the outer diameter of the electrode carrier 13 after extension can be adjusted, so that the device can be applicable to patients with different duodenal inner diameters, such as adult and pediatric patients, and avoid the problems such as the risk of mechanical damage to the duodenal wall tissue and physiological function disorder caused by the over-expansion of the duodenal inner diameter after the electrode carrier 13 is extended; if the moving distances of the middle catheter 11 and the inner catheter 12 relative to the outer catheter 10 are different, the rotation angles of the support arms 24 in the two support parts 20 are different. At this time, the cross-sectional shape of the electrode carrier 13 in the extended state is trapezoidal. The bulbous part (i.e., the upper part) with a frustum of a cone shape in the duodenum can be ablated through the cooperation of the electrode carrier 13 and the ablation electrode 14, avoiding over-ablation or incomplete ablation caused by uneven contact pressure at each point between the electrode carrier 13 and the inner wall of the bulbous part, and thus avoiding damage to the normal physiological structure of the intestine. Through the above scheme, the device can not only be applicable to the horizontal part, ascending part and descending part with little change in the duodenal inner diameter, but also be applicable to the bulbous part with a frustum of a cone shape. At the same time, the outer diameter of the electrode carrier 13 can be adjusted according to the different duodenal inner diameters of the patients, ensuring the fitting effect between the device and the inner wall of the duodenum, being able to more effectively achieve comprehensive circumferential ablation, and also improving the applicable range of the device.

[0069] It should be noted that the duodenum includes, according to its location: the bulb (inner diameter 3 - 5 cm, anatomical shape is a frustum of a cone), the descending part (inner diameter 2.5 - 3 cm), the horizontal part (inner diameter 2.5 - 3 cm), and the ascending part (inner diameter 2.5 - 3 cm).

[0070] Secondly, please refer to again Figure 5 , an annular groove 16 is formed on the outer side of the middle catheter 11, an annular boss 25 is arranged inside the first support bushing 21, and the annular groove 16 and the annular boss 25 are adapted to each other. The middle catheter 11 and the first support bushing 21 are rotationally connected through the cooperation of the annular groove 16 and the annular boss 25.

[0071] Thirdly, please refer to together Figure 4 、 Figure 6 、 Figure 13 and Figure 14 As shown, a guide ring 26 is fixed at one end of the support arm 24 away from the second support bushing 22. An expansion ring 27 is slidably connected inside a plurality of guide rings 26. Hemispherical end heads 28 and anti - detachment rings 29 are respectively fixed at both ends of the expansion ring 27, and the expansion ring 27 and the anti - detachment ring 29, as well as the hemispherical end heads 28 and the anti - detachment ring 29, are adapted to each other. Among them, when the support part 20 is in the extended state, the expansion ring 27 is in a circular ring shape, and when the support part 20 is in the contracted state, the expansion ring 27 is in a spiral shape.

[0072] Furthermore, the material of the guide ring 26 is preferably nitinol.

[0073] In this embodiment, the telescopic driving part 30 drives the outer catheter 10 and the inner catheter 12 to move. The two support parts 20 are respectively driven by the outer catheter 10 and the inner catheter 12 to operate, so that the support arm 24 rotates. The support arm 24 rotates to support the electrode carrier 13, so that the electrode carrier 13 changes from the contracted state to the extended state. At the same time, the spiral - shaped expansion ring 27 is expanded by the support arm 24, so that the expansion ring 27 changes from the spiral shape to the circular ring shape. The circular - ring - shaped expansion ring 27 supports the end of the extended - state electrode carrier 13, so that the shape of the electrode carrier 13 is presented as a cylinder or a frustum of a cone, improving the fitting effect between the electrode carrier 13 and the inner wall of the duodenum. At the same time, after ablation, when the support part 20 and the electrode carrier 13 synchronously change from the extended state to the contracted state, the expansion ring 27 changes from the circular ring shape to the spiral shape. During this process, one end of the expansion ring 27 is wound relative to the other end. The anti - detachment ring 29 guides the end of the expansion ring 27, so that the end of the expansion ring 27 can move along the outer wall of the expansion ring 27 during the winding process, avoiding the end of the expansion ring 27 moving outside the guide ring 26, resulting in the guide ring 26 being unable to change to the spiral shape.

[0074] Secondly, please refer to againFigure 6 The diameter of the hemispherical end 28 is larger than the inner diameter of the anti-slip ring 29.

[0075] In this embodiment, through the above-mentioned arrangement, the cooperation between the hemispherical end 28 and the anti-slip ring 29 can prevent the anti-slip ring 29 from detaching from the expansion ring 27, resulting in the anti-slip ring 29 being unable to guide the end of the expansion ring 27.

[0076] Please refer again Figures 7 to 10 Two guide slots 17 are provided on the outside of the handle 15, and the two guide slots 17 are adapted one to one with the two telescopic drive parts 30. The telescopic drive parts 30 include a guide rod 31, a drive key 32 and an elastic element 33. The guide rod 31 in one telescopic drive part 30 is fixed to the end of the outer side of the outer catheter 10 away from the electrode carrier 13, and the guide rod 31 in the other telescopic drive part 30 is fixed to the end of the outer side of the inner catheter 12 away from the electrode carrier 13. The drive key 32 is slidably connected to the upper end of the guide rod 31. The drive key 32 and the guide slot 17 is adapted, and the upper end of the driving key 32 passes through the guide groove 17 and extends to the outside of the handle 15. The elastic element 33 is assembled between the guide rod 31 and the driving key 32. A plurality of limiting teeth 34 are evenly provided on both sides of the upper end of the driving key 32. A plurality of stopping teeth 18 are provided on the inner wall of the handle 15, and the limiting teeth 34 and the stopping teeth 18 are adapted. When the limiting teeth 34 and the stopping teeth 18 contact each other, the handle 15 can form a limit on the driving key 32 through the cooperation of the limiting teeth 34 and the stopping teeth 18, wherein the elastic element 33 is always in a compressed state.

[0077] In this embodiment, when ablation is performed on the inner wall of the duodenum, the device is transported to the inside of the duodenum so that the electrode carrier 13 reaches the target position, the driving key 32 is pressed, so that the limiting tooth 34 and the stop tooth 18 are disengaged from each other, and the limit formed by the handle 15 on the driving key 32 is released, and the driving key 32 is pushed. The driving key 32 is connected to the guide rod 31 through a sliding connection, so that the driving key 32 drives the guide rod 31 to move, and the guide rod 31 is fixedly connected to the outer catheter 10, so that the guide rod 31 drives the outer catheter 10 to move in a direction close to the electrode carrier 13, and the outer catheter 10 is fixedly connected to the outer catheter 10. Through the fixed connection between the outer catheter 10 and the second support sleeve 22, the second support sleeve 22 moves toward the direction close to the first support sleeve 21, thereby causing the support arm 24 to rotate and drive the electrode carrier 13 to change from a contracted state to an extended state, releasing the drive key 32, and driving the drive key 32 to reset through the elastic element 33 in the compressed state, and making the stop tooth 18 and the limit tooth 34 contact each other again, and forming a limit on the drive key 32 through the handle 15 to prevent the outer catheter 10 from moving and the support arm 24 from rotating, causing the outer diameter of the electrode carrier 13 to change.

[0078] It should be noted that, in the above embodiments, only the telescopic driving part 30 connected to the outer catheter 10 is taken as an example to illustrate its movement process. The movement mode of the telescopic driving part 30 connected to the inner catheter 12 is the same except that the moving direction is opposite. Therefore, no further elaboration will be made here.

[0079] Please refer to again Figure 2 、 Figure 3 、 Figure 11 and Figure 12 As shown, the inner support assembly 40 includes a fixed collar 41, a movable collar 42 and an inner support framework 43. The fixed collar 41 is rotatably connected to the outer side of the middle catheter 11, the movable collar 42 is fixed to the outer side of the middle catheter 11, and the inner support framework 43 is assembled between the fixed collar 41 and the movable collar 42. Among them, the first support bushing 21 in the support part 20 connected to the inner catheter 12 is fixedly connected to the fixed collar 41.

[0080] In this embodiment, when ablating the curved part in the duodenum, when the electrode carrier 13 in the extended state cannot fit the outer bend of the curved part, the inner support driving part 50 drives the middle catheter 11 to rotate. Due to the fixed connection between the middle catheter 11 and the movable collar 42, the middle catheter 11 drives the movable collar 42 to rotate synchronously. Since one end of the inner support framework 43 is fixedly connected to the movable collar 42, the movable collar 42 drives one end of the inner support framework 43 to rotate (in this process, the inner catheter 12 is in a static state, and at the same time, the first support bushing 21 and the second support bushing 22 connected to the inner catheter 12 both remain in a static state. Since the above-mentioned second support bushing 22 is fixedly connected to the fixed collar 41, the fixed collar 41 remains static relative to the inner catheter 12, that is, the fixed collar 41 will not rotate synchronously with the middle catheter 11), so that the pitch and outer diameter of the inner support framework 43 increase synchronously. When the inner support framework 43 fits the inner wall of the electrode carrier 13, the inner support framework 43 can support the electrode carrier 13 until the electrode carrier 13 completely fits the outer bend of the curved part. After starting the ablation instrument, the curved part of the duodenum is ablated through the ablation electrode 14. Through the above scheme, when the device ablates the curved part of the duodenum, the inner support framework 43 with an increased outer diameter supports the inner wall of the electrode carrier 13, so that the electrode carrier 13 and the ablation electrode 14 can completely fit the outside of the curved part, thereby realizing complete circumferential ablation of the curved part, ensuring the ablation effect, reducing the difficulty, duration and risk of the surgical operation, and improving the applicability of the device.

[0081] Please refer to again Figures 7 to 9As shown in the figure, an inner support driving part 50 is assembled inside the handle 15. The inner support driving part 50 includes a driven gear 51 and a driving handle 52. The driven gear 51 is fixed on the outer side of the middle catheter 11 and is located inside the handle 15. The driving handle 52 is rotatably connected to the inside of the driven gear 51 through a shaft rod, and the upper end of the driving handle 52 extends outside the handle 15. A driving gear is arranged at one end of the driving handle 52 and is located inside the handle 15, and the driving gear is meshed with the driven gear 51.

[0082] In this embodiment, when ablating the curved part in the duodenum, rotate the driving handle 52. Through the meshing connection between the driving handle 52 and the driven gear 51 and the fixed connection between the driven gear 51 and the middle catheter 11, the driving handle 52 drives the driven gear 51 and the middle catheter 11 to rotate. The middle catheter 11 drives the movable collar 42 to rotate, thereby adjusting the outer diameter of the inner support frame 43. The inner support frame 43 supports the electrode carrier 13 until the electrode carrier 13, the ablation electrode 14 and the outer bend of the curved part are fitted together, avoiding the situation that the electrode carrier 13 and the ablation electrode 14 cannot be completely fitted with the outer bend part when the device ablates the curved part, so that the device can achieve complete circumferential ablation of the curved part.

[0083] Embodiment Two

[0084] A working method of an ablation catheter, applicable to an ablation catheter in any one of Embodiment One, includes the following steps:

[0085] Stp1: Drive the two telescopic driving parts 30 to operate respectively, and drive the outer catheter 10 and the inner catheter 12 to move towards each other through the two driving keys 32;

[0086] Stp2: Drive the second support bush 22 in the two support parts 20 to move towards each other through the outer catheter 10 and the inner catheter 12 respectively, so that the support part 20 drives the electrode carrier 13 to change from the contracted state to the extended state synchronously until the electrode carrier 13 reaches the expected shape. Among them, if the moving distances of the outer catheter 10 and the inner catheter 12 are the same, the cross-sectional shape of the electrode carrier 13 is rectangular; if the moving distances of the outer catheter 10 and the inner catheter 12 are different, the cross-sectional shape of the electrode carrier 13 is trapezoidal;

[0087] Stp3: Rotate the driving handle 52, drive the middle catheter 11 to rotate through the driving handle 52, drive the movable collar 42 to rotate through the middle catheter 11, and drive the inner support frame 43 to perform spiral radial expansion through the movable collar 42, so that the inner support frame 43 supports the inner wall of the electrode carrier 13.

[0088] The working principle of the present invention is:

[0089] When ablating the inner wall of the duodenum, the electrode carrier 13 is placed inside the duodenum. Under the guidance of an imaging device, the device is delivered to the target position. Press and push the two driving keys 32. By driving the outer catheter 10 and the inner catheter 12 to move towards each other respectively through the two driving keys 32, the two second support bushings 22 move towards the first support bushing 21. Through the cooperation of the second support bushing 22 and the swing arm 23, while the second support bushing 22 moves, the support arm 24 rotates relative to the second support bushing 22. The contracted electrode carrier 13 is supported by multiple support arms 24, so that the support part 20 and the electrode carrier 13 are synchronously changed from the contracted state to the extended state until the electrode carrier 13 is in contact with the inner wall and the ablation electrode 14 is in contact with the inner wall. During the above process, if the moving distances of the middle catheter 11 and the inner catheter 12 relative to the outer catheter 10 are the same, the rotation angles of the support arms 24 in the two support parts 20 are the same. The cross-sectional shape of the electrode carrier 13 in the extended state is rectangular. The horizontal part, ascending part and descending part of the duodenum can be ablated through the ablation electrode 14. At the same time, by synchronously adjusting the moving distances of the outer catheter 10 and the inner catheter 12 and controlling the rotation angle of the support arm 24, the outer diameter of the extended electrode carrier 13 can be adjusted, so that the device can be applicable to patients with different duodenal inner diameters, such as adult and pediatric patients, and avoid the problems such as the risk of mechanical damage to the duodenal wall tissue and physiological function disorder caused by the over-expansion of the duodenal inner diameter by the extended electrode carrier 13. If the moving distances of the middle catheter 11 and the inner catheter 12 relative to the outer catheter 10 are different, the rotation angles of the support arms 24 in the two support parts 20 are different. The cross-sectional shape of the electrode carrier 13 in the extended state is trapezoidal. The bulbous part with a frustum shape in the duodenum can be ablated through the cooperation of the electrode carrier 13 and the ablation electrode 14. When the ablation position is a curved part, rotate the driving handle 52. The middle catheter 11 and the movable collar 42 are driven to rotate by the driving handle 52. The inner support frame 43 is driven by the movable collar 42 to expand radially in a spiral manner, so that the inner support frame 43 supports the inner wall of the electrode carrier 13 until the electrode carrier 13 is in contact with the outer bend of the curved part. Start the ablation instrument, and ablate the inner wall of the duodenum through the ablation electrode 14. Repeat the ablation multiple times until the entire inner wall of the duodenum is completely ablated.

[0090] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention. The structures, devices and operation methods not specifically described and explained in the present invention are implemented according to the conventional means in the art without special description and limitation.

Claims

1. An ablation catheter, characterized in that: It includes an outer catheter (10), a middle catheter (11), and an inner catheter (12) that are coaxially arranged from outside to inside in sequence. There is a clearance fit between the outer catheter (10) and the middle catheter (11), and between the middle catheter (11) and the inner catheter (12). One end on the outside of the outer catheter (10) is equipped with an electrode carrier (13), and an ablation electrode (14) is arranged on the outside of the electrode carrier (13). The other end of the outer catheter (10) is equipped with a handle (15), and the handle (15) is rotatably connected to the middle catheter (11), and further includes: two support parts (20), both of the two support parts (20) are assembled on the outside of the middle catheter (11). The support part (20) includes a first support bushing (21), a second support bushing (22), a plurality of swing arms (23), and a plurality of support arms (24). The first support bushing (21) is rotatably connected to the outside of the middle catheter (11). The second support bushing (22) in one support part (20) is fixed to the outside of the inner catheter (12), and the second support bushing (22) in the other support part (20) is fixed to the outside of the outer catheter (10). A plurality of the swing arms (23) are all rotatably connected to the inside of the side wall of the first support bushing (21), and a plurality of the support arms (24) are all rotatably connected to the inside of the side wall of the second support bushing (22). The swing arms (23) and the support arms (24) are slidably connected; two telescopic driving parts (30), both of the two telescopic driving parts (30) are assembled inside the handle (15), and there is a one-to-one adaptation between the outer catheter (10) and the telescopic driving part (30), and between the inner catheter (12) and the telescopic driving part (30). The two telescopic driving parts (30) are configured to be able to drive the outer catheter (10) or the inner catheter (12) to move respectively; wherein, after respectively operating the two telescopic driving parts (30), the electrode carrier (13) and the support part (20) are switched between an extended state and a contracted state. In the extended state, the cross-sectional shape of the electrode carrier (13) is one of the following shapes: trapezoid, rectangle.

2. The ablation catheter according to claim 1, characterized in that: An annular groove (16) is formed on the outside of the middle catheter (11), and an annular boss (25) is arranged inside the first support bushing (21), and the annular groove (16) and the annular boss (25) are adapted to each other.

3. The ablation catheter according to claim 1, wherein: A guide ring (26) is fixed to the end of the support arm (24) far from the second support bushing (22). An expansion ring (27) is slidably connected inside a plurality of the guide rings (26). Hemispherical end heads (28) and anti-disengagement rings (29) are respectively fixed to both ends of the expansion ring (27), and the expansion ring (27) and the anti-disengagement ring (29), and between the hemispherical end heads (28) and the anti-disengagement ring (29) are all adapted to each other. Among them, when the support part (20) is in the extended state, the expansion ring (27) is in a circular ring form, and when the support part (20) is in the contracted state, the expansion ring (27) is in a spiral form.

4. The ablation catheter according to claim 3, characterized in that: The diameter of the hemispherical end head (28) is larger than the inner diameter of the anti-disengagement ring (29).

5. An ablation catheter according to claim 1, characterized in that: Two guiding through grooves (17) are formed on the outer side of the handle (15). The telescopic driving part (30) includes a guiding rod (31), a driving key (32) and an elastic element (33). Among them, the guiding rod (31) in one telescopic driving part (30) is fixed to one end of the outer side of the outer catheter (10) far away from the electrode carrier (13), and the guiding rod (31) in the other telescopic driving part (30) is fixed to one end of the outer side of the inner catheter (12) far away from the electrode carrier (13). The driving key (32) is slidably connected to the upper end inside the guiding rod (31). The driving key (32) is adapted to the guiding through groove (17), and the upper end of the driving key (32) penetrates through the inside of the guiding through groove (17) and extends to the outside of the handle (15). The elastic element (33) is assembled between the guiding rod (31) and the driving key (32). Among them, the elastic element (33) is always in a compressed state.

6. The ablation catheter according to claim 5, wherein: A plurality of limiting teeth (34) are evenly formed on both sides of the upper end of the driving key (32). A plurality of stopping teeth (18) are formed on the inner wall of the handle (15), and the limiting teeth (34) are adapted to the stopping teeth (18).

7. The ablation catheter according to claim 1, wherein: An inner support assembly (40) is assembled on the outer side of the middle catheter (11) and between the two support parts (20). The inner support assembly (40) includes a fixed collar (41), a movable collar (42) and an inner support framework (43). The fixed collar (41) is rotatably connected to the outer side of the middle catheter (11). The movable collar (42) is fixed to the outer side of the middle catheter (11). The inner support framework (43) is assembled between the fixed collar (41) and the movable collar (42). Among them, the first support bushing (21) in the support part (20) connected to the inner catheter (12) is fixedly connected to the fixed collar (41).

8. The ablation catheter according to claim 1, wherein: An inner support driving part (50) is assembled inside the handle (15). The inner support driving part (50) includes a driven gear (51) and a driving handle (52). The driven gear (51) is fixed to the outer side of the middle catheter (11) and inside the handle (15). The driving handle (52) is rotatably connected to the inside of the driven gear (51). One end of the driving handle (52) is provided with a driving gear, and the driving gear is meshed with the driven gear (51).

9. A working method of an ablation catheter, applicable to an ablation catheter according to any one of claims 1 to 8, characterized in that: Including the following steps: Stp1: Drive the two telescopic driving parts (30) to operate respectively, and drive the outer catheter (10) and the inner catheter (12) to move towards each other through the two driving keys (32); Stp2: Drive the two support parts (20) to operate through the outer catheter (10) and the inner catheter (12) respectively, so that the support parts (20) drive the electrode carrier (13) to synchronously change from the contracted state to the extended state until the electrode carrier (13) reaches the expected shape. Among them, if the moving distances of the outer catheter (10) and the inner catheter (12) are the same, the cross-sectional shape of the electrode carrier (13) is rectangular; if the moving distances of the outer catheter (10) and the inner catheter (12) are different, the cross-sectional shape of the electrode carrier (13) is trapezoidal. Stp3: Rotate the drive handle (52), drive the middle catheter (11) and the movable collar (42) to rotate through the drive handle (52), drive the inner support frame (43) to expand radially in a spiral manner through the movable collar (42), so that the inner support frame (43) supports the inner wall of the electrode carrier (13).

Images