Ablation Catheter

Abstract

The present application relates to an ablation catheter, which comprises a catheter body and a support frame arranged at the distal end of the catheter body, the support frame comprises a connection frame and a bearing frame, the bearing frame is arranged at the distal end relative to the connection frame, the distal end of the connection frame is connected to the proximal end of the bearing frame, the proximal end of the connection frame is connected to the distal end of the catheter body, the connection frame is provided with a conductive part, and the bearing frame is provided with an electrode group insulated from the conductive part; wherein the sum of the electrode surface area of ​​the electrode group and the electrode surface area of ​​the conductive part is used as a reference electrode area, and the reference electrode area is within a preset interval; and / or, the electrode surface area of ​​the electrode group is smaller than the electrode surface area of ​​the conductive part; and / or, when at least two electrode groups are provided along the axial direction of the bearing frame, the electrode spacing between the conductive part and an adjacent electrode group is greater than the electrode spacing between two adjacent electrode groups. The ablation catheter of the present application can effectively increase the ablation depth.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices, and in particular to an ablation catheter. Background Art

[0002] Atrial fibrillation (AF) is one of the most common arrhythmias in clinical practice, and its incidence has been gradually increasing in recent years. Non-drug treatment of AF has been a research hotspot in recent years. For example, electrical isolation using catheter ablation technology can effectively prevent the recurrence of AF and maintain sinus rhythm.

[0003] Catheter ablation technology is a vascular interventional surgery in which the tip (distal end) of the catheter is inserted into the human body to reach the corresponding treatment target location. The energy medium (such as radio frequency, ultrasound, pulse, etc.) is sent through the energy platform connected to the tail end (proximal end) of the catheter. The distal end of the catheter is equipped with an energy delivery electrode. When the electrode is in contact with the tissue, it transfers energy to the tissue, thereby performing tissue ablation.

[0004] However, current catheter ablation still has the problem of shallow ablation depth and difficulty in achieving the expected ablation effect, which requires further improvement. Summary of the invention

[0005] In view of this, an object of the present application is to provide an ablation catheter that can effectively increase the ablation depth.

[0006] The present application provides an ablation catheter, comprising a catheter body and a supporting frame arranged at the distal end of the catheter body, the supporting frame comprising a connecting frame and a bearing frame, the bearing frame is arranged at the distal end relative to the connecting frame, the distal end of the connecting frame is connected to the proximal end of the bearing frame, and the proximal end of the connecting frame is connected to the distal end of the catheter body, the connecting frame is provided with a conductive part, the bearing frame is provided with an electrode group insulated from the conductive part, the conductive part and the electrode group are used to respectively connect two output terminals of an energy generator to transmit the ablation energy output by the energy generator to a target tissue area; wherein the sum of the electrode surface area of ​​the electrode group and the electrode surface area of ​​the conductive part is used as a reference electrode area, and the reference electrode area is within a preset interval; and / or, the electrode surface area of ​​the electrode group is smaller than the electrode surface area of ​​the conductive part; and / or, when at least two electrode groups are provided along the axial direction of the bearing frame, the electrode spacing between the conductive part and an adjacent electrode group is greater than the electrode spacing between two adjacent electrode groups.

[0007] The ablation catheter provided by the present application has a support frame at the distal end of the catheter body, the support frame includes a bearing frame and a connecting frame, an electrode group is provided on the bearing frame, a conductive part is provided on the connecting frame, the sum of the electrode surface area of ​​the electrode group and the electrode surface area of ​​the conductive part is the reference electrode area, the reference electrode area is within a preset interval, and / or the electrode surface area of ​​the electrode group is smaller than the electrode surface area of ​​the conductive part, and / or when at least two electrode groups are provided along the axial direction of the bearing frame, the electrode spacing between the conductive part and an adjacent electrode group is greater than the electrode spacing between two adjacent electrode groups. By utilizing at least one of the three factors of the reference electrode area, the electrode surface area, and the electrode spacing, the ablation depth during ablation of the ablation catheter of the present application is increased. When the reference electrode area is within the preset range, on the one hand, it can ensure that the reference electrode area is not too small, so as to avoid the ablation energy being too weak to produce sufficient ablation depth; on the other hand, it can ensure that the reference electrode area is not too large, so as to avoid the structural size of the supporting skeleton and the actual space of the ablation site not being supported and accidental injury to the unintended target area; when the electrode surface area of ​​the electrode group is smaller than the electrode surface area of ​​the conductive part, the current density of the electrode group will be relatively larger, and the ablation energy can be more concentrated on the bearing frame. Since the bearing frame is arranged at the distal end relative to the connecting frame, the conductive part and the electrode group cooperate to transmit the ablation energy to the target tissue area. When ablation energy is applied, the ablation depth of the tissue ablation performed by the support frame at the distal end will be deeper; when the electrode spacing between the conductive part and an adjacent electrode group is greater than the electrode spacing between two adjacent electrode groups, since the positions between the conductive part and the electrode groups are relatively dispersed and the positions between the electrode groups are more concentrated, the ablation energy can be more concentrated on the support frame, and then the ablation depth of the tissue ablation performed by the support frame will be deeper, and since the positions between the conductive part and the electrode groups are relatively dispersed, the electric field coverage range formed between the conductive part and the electrode groups will be larger, thereby being able to diffuse to deeper areas to increase the ablation depth. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0009] Figure 1 It is a schematic structural diagram of an embodiment of the ablation catheter of the present application.

[0010] Figure 2 for Figure 1 A front view of the ablation catheter is shown.

[0011] Figure 3It is a curve diagram showing the relationship between the ablation depth of the ablation catheter and the reference electrode area S0.

[0012] Figure 4 is the ratio of the ablation depth of the ablation catheter to the electrode surface area δ AB relationship curve diagram.

[0013] Figure 5 is the ablation depth and electrode spacing of the ablation catheter relationship curve diagram.

[0014] Figure 6 is the ablation depth of the ablation catheter and the electrode spacing Δ AB relationship curve diagram.

[0015] Figure 7 It is a schematic structural diagram of an embodiment of the ablation catheter of the present application.

[0016] Figure 8 for Figure 7 Electric field simulation diagram of the ablation catheter shown.

[0017] Fig. 9 It is a structural schematic diagram of another embodiment of the ablation catheter of the present application.

[0018] Fig.10 for Fig. 9 Electric field simulation diagram of the ablation catheter shown.

[0019] Fig.11 This is a schematic structural diagram of yet another embodiment of the ablation catheter of the present application.

[0020] Fig.12 for Fig.11 Electric field simulation diagram of the ablation catheter shown.

[0021] Fig.13 This is a schematic structural diagram of another embodiment of the ablation catheter of the present application.

[0022] Fig.14 for Fig.13 Electric field simulation diagram of the ablation catheter shown.

[0023] The following are the descriptions of the reference numerals:

[0024] 100, ablation catheter; 10, catheter body; 20, traction tube; 30, support frame; 32, conductive part; 34, electrode group; 34-1, first electrode group; 34-2, second electrode group; 34a, first electrode; 34b, second electrode; 36, supporting frame; 361, supporting rod; 361a, first supporting rod; 361b, second supporting rod; 37, reference electrode; 38, connecting frame; 381, grid group; 382, ​​connecting grid; 383, first main grid; 384, first sub-grid; 385, second main grid; 386, second sub-grid; 39, marking electrode. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0026] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0027] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0028] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", and "set" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0029] It should be noted that the terms "proximal end" and "distal end" used below can be understood according to the common meaning in the field of medical devices, where "proximal end" refers to the end close to the operator (such as a doctor, etc.); "distal end" refers to the end away from the operator.

[0030] The present application provides an ablation catheter, which is delivered to a target tissue area in a patient's body when in use, so as to ablate and isolate the target tissue area. The target tissue area can be located in the heart, including but not limited to the mitral isthmus, the tricuspid isthmus, the top of the left atrium, the pulmonary vein, or a triggering focus with typical atrial flutter and non-pulmonary vein origin (such as the left atrial appendage, the superior vena cava, the coronary sinus ostium), etc. It can be understood that the target tissue area is not limited to being located in the heart, but can also be located on other body tissues, and the present application does not limit this.

[0031] Figure 1 and Figure 2 The figure shows a specific embodiment of the ablation catheter of the present application. The ablation catheter 100 shown includes a catheter body 10 and a support frame 30, and the support frame 30 is arranged at the distal end of the catheter body 10. The ablation catheter 100 can be delivered to the target tissue area, such as the inside of the heart, by a delivery device. The delivery device includes but is not limited to components such as a sheath tube and a handle. It should be noted that the specific structure of the delivery device can refer to the relevant technology in the field, and this application will not repeat it.

[0032] The catheter body 10 is constructed as a hollow tubular structure. The central axis L of the catheter body 10 extends along the line connecting the distal end and the proximal end. A single axial lumen or central lumen (not shown) is provided in the catheter body 10. According to actual needs, the catheter body 10 may also have multiple lumens to accommodate pull wires, lead wires, sensor cables, and any other wires, cables, and / or tubes that may be required in a specific application.

[0033] It is understood that the catheter body 10 can also be of any suitable structure and can be made of any suitable material, for example, a structure includes an outer wall made of a polymer material such as polyurethane or polyether block amide (PEBAX). The catheter body 10 has a certain flexibility and can be bent to adapt to the curved structure inside the heart. The diameter of the catheter body 10 is approximately 8F, that is, the outer diameter of the catheter body 10 is approximately 2.67mm. It should be noted that the size of the catheter body 10 is only for illustration and does not constitute a specific limitation.

[0034] The support frame 30 is made of a material having a shape memory effect and can be in a self-expanding state after being formed to have a predetermined radial dimension. Figure 1Schematic diagram of the state of the support skeleton 30 when it is not subjected to external force after forming. At this time, it is roughly lantern-shaped and its maximum outer diameter is D0. The support skeleton 30 can be prepared as a whole or divided into different local structures for preparation. For example, the support skeleton 30 can be formed by weaving a braided wire with a shape memory effect; or, it can also be made by cutting a tube with a shape memory effect as a whole; or, it can also be obtained by a 3D metal printing process; or, a part of the structure of the support skeleton 30 is formed by weaving a braided wire with a shape memory effect, and another part of the structure is cut by a tube with a shape memory effect, and then the two parts of the structure are fixedly connected to each other by welding or by a connecting structure. Among them, the material with shape memory effect includes but is not limited to metal materials and non-metallic materials with memory effect. Non-metallic materials are, for example, elastic polymer materials or other superelastic materials. Metal materials are, for example, but not limited to biocompatible metal materials such as stainless steel, nickel-titanium alloy, cobalt-based alloy, and optionally, the metal material is stainless steel. In this embodiment, the support skeleton 30 is cut and shaped by a nickel-titanium alloy tube.

[0035] The support skeleton 30 has a contracted state and an expanded state. It should be noted that the expanded state refers to the state in which the support skeleton 30 is fully expanded, that is, the support skeleton 30 is in a freely expanded working state, for example, the support skeleton 30 is not pressed into the sheath tube of the conveying device and the support skeleton 30 is not subjected to any other external force. At this time, the support skeleton 30 is free to expand radially, and the outer diameter of the support skeleton 30 is greater than the outer diameter of the sheath tube; the contracted state refers to the state in which at least part of the structure of the support skeleton 30 is not fully expanded, that is, the support skeleton 30 is constrained by a constraining element, for example, the state in which the support skeleton 30 is pressurized into the sheath tube of the conveying device, at this time, the support skeleton 30 is contracted radially and the outer diameter of the support skeleton 30 is less than the outer diameter of the sheath tube.

[0036] In this embodiment, Figure 1 The structure of the support frame 30 in an expanded state is shown. At this time, the two ends of the support frame 30 are closed and the middle part is expanded, and the outer contour of the support frame 30 is roughly spherical. In the expanded state, the support frame 30 can also be other structures, such as egg-shaped, pumpkin-shaped, lantern-shaped, oval-shaped, etc.

[0037] exist Figure 1 Based on the structure shown, the support skeleton 30 can be contracted radially inward relative to the central axis L of the catheter body 10, that is, the middle part of the support skeleton 30 is also retracted toward the central axis of the catheter body 10, and the support skeleton 30 will be straightened to a roughly linear state in the contracted state. The axial length of the support skeleton 30 in the contracted state will be greater than its axial length in the expanded state.

[0038] In the contracted state, the support frame 30 can be accommodated in the sheath of the delivery device so as to be conveniently delivered into the human body through the sheath. When the target tissue area is reached through the sheath, the support frame 30 is released from the sheath and then expands radially to Figure 1 The support frame 30 may expand radially by itself when it is extended out of the sheath, or the support frame 30 may expand radially under human intervention after extending out of the sheath.

[0039] In this embodiment, the support frame 30 includes a bearing frame 36 and a connecting frame 38. The bearing frame 36 is arranged at the distal end relative to the connecting frame 38. The distal end of the connecting frame 38 is connected to the proximal end of the bearing frame 36, and the proximal end of the connecting frame 38 is connected to the distal end of the catheter body 10. The connecting frame 38 is provided with a conductive part 32, and the bearing frame 36 is provided with an electrode group 34 insulated from the conductive part 32. The conductive part 32 and the electrode group 34 are respectively connected to two output terminals of an energy generator (such as an ablation device, etc.) to transmit the ablation energy output by the energy generator to the target tissue area. The electrode group 34 is close to the target tissue area to be ablated, so that the surrounding tissue cells are necrotic under the action of the ablation energy of the energy generator, so as to prevent the propagation of abnormal electrical signals and achieve the purpose of treating the disease.

[0040] In this embodiment, there are at least two electrode groups 34 along the axial direction of the supporting frame 36, for example, 34-1, 34-2...34-N from the distal end and the proximal end, respectively, wherein the electrode spacing between the conductive portion 32 and an adjacent electrode group 34 refers to the electrode spacing between the conductive portion 32 and the electrode group 34-N, and the electrode spacing between two adjacent electrode groups 34 includes the electrode spacing between the electrode groups 34-1 and 34-2, the electrode spacing between the electrode groups 34-2 and 34-3...the electrode spacing between the electrode groups 34-(N-1) and 34-N, and other multiple electrode spacings.

[0041] See also Figure 1 to Figure 2 In some embodiments, two electrode groups 34 are provided along the axial direction of the supporting frame 36, namely, a first electrode group 34-1 and a second electrode group 34-2. The first electrode group 34-1 is provided at the distal end relative to the second electrode group 34-2. The electrode spacing between the conductive portion 32 and an adjacent electrode group 34 refers to the electrode spacing between the conductive portion 32 and the second electrode group 34-2. The electrode spacing between two adjacent electrode groups 34 refers to the electrode distance between the first electrode group 34-1 and the second electrode group 34-2.

[0042] Still see Figure 1 to Figure 2In some embodiments, the first electrode group 34-1 includes a plurality of first electrodes 34a, and the second electrode group 34-2 includes a plurality of second electrodes 34b. The plurality of first electrodes 34a are arranged at intervals around the central axis of the support skeleton 30, and the plurality of second electrodes 34b are arranged at intervals around the central axis of the support skeleton 30. The plurality of first electrodes 34a form a ring, and the plane where the ring is located is perpendicular to the central axis of the support skeleton 30. The plurality of second electrodes 34b form a ring, and the plane where the ring is located is perpendicular to the central axis of the support skeleton 30. Therefore, when the first electrode 34a and the second electrode 34b are used to ablate the target tissue area, the support skeleton 30 can ablate the target tissue area more uniformly.

[0043] In some embodiments, the entirety of the connection frame 38 may be configured as the conductive portion 32, and in other embodiments, a portion of the connection frame 38 may be configured as the conductive portion 32, for example, the distal end, proximal end or middle portion of the connection frame 38 may be configured as the conductive portion 32. In the case where the entirety of the connection frame 38 is configured as the conductive portion 32, the electrode spacing between the conductive portion 32 and the second electrode group 34-2 is the distance between any second electrode 34b and the farthest end of the connection frame 38 in its axial extension direction, and the electrode spacing between the first electrode group 34-1 and the second electrode group 34-2 is the distance between any first electrode 34a and a second electrode 34b in its axial extension direction.

[0044] In order to improve the ablation depth, the relationship between the surface area size, arrangement spacing and other factors of the conductive part 32 and the electrode group 34 and the ablation depth is analyzed in the embodiment of the present application. For the convenience of description, the area where the electrode group 34 is located is defined as area A, the area where the conductive part 32 is located is defined as area B, the location of the first electrode group 34-1 in area A is defined as area A1, and the location of the second electrode group 34-2 in area A is defined as area A2. The distance between any second electrode 34b and the farthest end of the conductive part 32 in the axial extension direction is defined as Δ AB The distance between any first electrode 34a and a second electrode 34b in its axial extension direction is defined as The reference electrode area is defined as S0, S 0＝ S A +S B ; The electrode surface area ratio is defined as δ AB , δ AB =S A / S B Among them, S A is the electrode surface area S of the first electrode group 34-1 A1 and the electrode surface area S of the second electrode group 34-2 A2 The sum of S A =S A1+S A2 ; S B is the electrode surface area of ​​the conductive portion 32 .

[0045] For ease of understanding, the electrode surface area is explained here, wherein the electrode surface area of ​​the conductive portion 32 refers to the effective current transmission area of ​​the conductive portion 32, that is, the electrode surface area can operably support the current to flow through the conductive portion 32, for example, between the conductive portion 32 and the target point contacted by the conductive portion 32. Similarly, the electrode surface area of ​​the electrode group 34 refers to the effective current transmission area of ​​the electrode group 34.

[0046] By using the control variable method, when only a single variable is changed, the relationship curve between the ablation depth and the reference electrode area S0 can be obtained as follows: Figure 3 As shown, the ablation depth and electrode area ratio δ AB The relationship curve is as follows Figure 4 As shown, the ablation depth is related to the electrode spacing Δ AB , The relationship curve is as follows Figure 5 , 6 shown. Specifically:

[0047] Figure 3 The relationship curve between ablation depth and reference electrode area S0 is shown. Since the size of reference electrode area S0 is related to the electrode surface area S of area A1, A1 , the electrode surface area S in region A2 A2 and the electrode surface area S in region B B The figure shows three curves, including:

[0048] The curve S1 corresponds to the situation that the electrode surface area S of the A1 region where the first electrode 34a is located is A1 The relationship between the reference electrode area S0 and the ablation depth when the electrode surface area S A1 When the electrode surface area ratio δ AB The reference electrode area S0 changes accordingly. It can be seen from the curve S1 that the reference electrode area S0 is proportional to the ablation depth at this time;

[0049] The curve S2 corresponds to the situation that the electrode surface area S of the A2 region where the second electrode 34b is located is A2 The relationship between the reference electrode area S0 and the ablation depth when the electrode surface area S A2 When the electrode surface area ratio δ AB The reference electrode area S0 changes accordingly. It can be seen from the curve S2 that the reference electrode area S0 is inversely proportional to the ablation depth.

[0050] The curve S3 corresponds to the situation that the electrode surface area S of the A1 region where the first electrode 34a is located is A1, the electrode surface area S of the A2 region where the second electrode 34b is located A2 The relationship between the reference electrode area S0 and the ablation depth when the electrode surface area S0 changes in proportion. A1 , S A2 When the proportion changes, the electrode surface area ratio δ AB The reference electrode area S0 remains unchanged as the electrode surface area S A1 , S A2 As can be seen from curve S3, at this time, the reference electrode area S0 is proportional to the ablation depth.

[0051] according to Figure 3 From the curves S1, S2 and S3, it can be seen that in order to increase the ablation depth, the electrode surface area S in the A1 region A1 Should be larger, the electrode surface area S in area A2 A2 Should be smaller, the overall electrode surface area S in area A A It can be slightly larger.

[0052] Figure 4 shows the ratio of ablation depth to electrode surface area δ AB When the reference electrode area S0 remains unchanged, the electrode surface area ratio δ AB In the process from the value infinitely approaching 0 to the value 1, the surface area S of the electrode in area A A Smaller than the electrode surface area S in zone B B The ablation depth first increases and then decreases, indicating that the electrode surface area is larger than δ AB It is not good to simply increase or decrease it. There is an upper limit to the change of this value. AB Starting from the value 1, it means that the electrode surface area S in area A A Greater than the electrode surface area S in zone B B During this process, the ablation depth basically continues to decrease.

[0053] When the electrode surface area ratio δ AB <1, the main radiation direction is concentrated in area A, that is, the energy and electric field are more distributed in the direction of area A, and as δ AB As δ decreases, this concentration trend becomes more obvious; AB >1, the main radiation direction is concentrated in area B, that is, the energy and electric field are more distributed in the direction of area B, and as δ AB With the increase of the population, this concentration trend becomes more obvious.

[0054] Depend on Figure 4 It can be seen that in order to increase the ablation depth, the electrode surface area ratio δ AB Need to go to AB<1, that is, the electrode surface area S of the electrode group 34 should be A Designed to be smaller than the electrode surface area S of the conductive portion 32 B The electrode surface area S of the electrode group 34 is A The reduction of can be achieved by reducing the length or width of the first electrode 34a and / or the second electrode 34b; or by reducing the number of the first electrode 34a and / or the second electrode 34b. B The increase can be achieved by increasing the mesh density of the conductive part 32 or increasing the overall size of the conductive part 32.

[0055] Figure 5 shows the ablation depth vs. electrode spacing The relationship curve of Figure 5 It can be seen that the electrode spacing It is negatively correlated with the ablation depth, that is, the ablation depth increases with the electrode spacing. However, the decreasing trend is relatively gentle. Therefore, in order to increase the ablation depth, the electrode spacing It should be smaller, that is, the distance between the first electrode 34a and the second electrode 34b should be as small as possible.

[0056] Figure 6 shows the ablation depth versus electrode spacing Δ AB The relationship curve of Figure 6 It can be seen that the electrode spacing Δ AB It is positively correlated with the ablation depth, that is, the ablation depth increases with the electrode spacing Δ AB Therefore, in order to increase the ablation depth, the electrode spacing Δ AB It should be as large as possible, that is, the distance between the second electrode 34 b and the conductive part 32 should be as large as possible.

[0057] Comprehensive consideration of electrode spacing Δ AB , The first electrode 34a can be placed as close to the distal end of the support frame 30 as possible to form a more concentrated electric field at the distal end; at the same time, the second electrode 34b is moved toward the distal end of the support frame 30, so that the distance between the A1 area and the A2 area is small, and the distance between the A2 area and the B area is large, thereby reducing the electrode distance Δ AB In addition, the electrode spacing Δ AB The increase can also improve the insulation performance of the electrode and avoid electrode breakdown caused by edge effects due to being too close.

[0058] In addition, it should be noted that the reference electrode area S0 and the electrode surface area ratio δ AB and the electrode spacing ΔAB , There are upper and lower limits:

[0059] (1) If the reference electrode area S0 is too small, the ablation depth is too shallow and has no practical application value; if the reference electrode area S0 is too large, the actual catheter tip structure and the actual ablation site space do not support it, and it is easy to accidentally injure the unintended target area. Therefore, considering comprehensively, the reference electrode area S0 can be designed within a preset range. Optionally, the preset range can be 0 <S0<500mm 2 .

[0060] (2) Electrode surface area ratio δ AB When it is too small or too large, the electric field will be sharply concentrated in area A or area B, and the local current density will be too high, which may easily lead to unexpected breakdown, gas microembolism, eschar and other adverse consequences. AB Can be designed to be 0<δ AB <1.

[0061] (3) Electrode spacing Δ AB If the distance is too small, the charges are largely distributed at the edges of adjacent electrodes with different polarities, and the local current density is too high, which can easily cause unexpected breakdown. AB When it is too large, the space structure does not support it, and the electric field is rapidly consumed over a longer distance. Although the ablation range is increased to a certain extent, the weakening effect on the ablation depth is more obvious. Therefore, the electrode spacing Δ AB Can be designed to be 2mm<Δ AB <20mm, electrode spacing Can be designed as

[0062] The above factors affecting the ablation depth include the reference electrode area S0, the electrode surface area ratio δ AB and the electrode spacing Δ AB , The above analysis is conducted separately. It should be understood that when designing the electrode, the optimization design can be conducted based on only one of the factors, or based on two, three or even all of the factors. When optimizing the design based on multiple factors, the adjustment principle in the above analysis is applied to the adjustment of each factor. Finally, the influence of each factor is balanced to obtain the optimized design solution, so that the electric field distribution of the ablation catheter 100 can be concentrated in the A area where the electrode group 34 is located, thereby increasing the ablation depth and improving the ablation effect.

[0063] This application uses the reference electrode area S0, electrode surface area ratio δ AB and the electrode spacing Δ AB , The relationship between the reference electrode area S0 and the ablation depth was analyzed, where the reference electrode area S0 affects the reference ablation depth, which refers to the initial basic level of ablation depth, to provide optimized comparison; the electrode surface area ratio δ AB Affects the radiation direction, further affecting the ablation depth; electrode spacing Δ AB Affects the electric field distribution and insulation performance; electrode spacing Δ AB , The electric field distribution is affected, and further the ablation depth is affected. Therefore, the above factors can be optimized by increasing the reference electrode area S0 within a preset range, and / or increasing the electrode surface area ratio δ AB Designed to be less than 1, and / or, the electrode spacing Δ AB Designed to be greater than That is, the electrode group 34 can have a greater current density, that is, the energy is more concentrated in the electrode group 34. Therefore, when the electrode group 34 is close to the target tissue area for ablation, the ablation depth can be effectively improved.

[0064] For the ablation catheter 100 of the present application, the energy can be concentrated on the A region where the first electrode group 34 - 1 and the second electrode group 34 - 2 are located through structural design, thereby increasing the ablation depth. Figure 3 , Figure 5 , Figure 7 Three specific embodiments of the ablation catheter 100 of the present application are shown respectively. The reference electrode area S0 of the support frame 30, the electrode surface area ratio δ AB , electrode spacing Δ AB , If at least one of them is different, the electric field distribution after power-on will also be different, specifically:

[0065] Figure 7 , Fig. 9 , Fig.11 Three types of support frames 30 are shown respectively, wherein Figure 7 and Fig. 9 The reference electrode area S0 and the electrode surface area ratio δ of the support skeleton 30 are shown in FIG. AB Same, but the electrode spacing Δ AB , different, Figure 7 The electrode spacing Δ AB Less than Fig. 9 The electrode spacing Δ AB , Figure 7 The electrode spacing in Greater than Fig. 9 The electrode spacing in Figure 7 and Fig.11 The support skeleton electrode spacing Δ AB , Same, but Figure 7 and Fig.11 The reference electrode area S0 and electrode surface area ratio δ AB different, Figure 7 The reference electrode area S0 is greater than Fig.11 The reference electrode area S0 in Figure 7 The electrode surface area ratio δ AB Greater than Fig.11 The electrode surface area ratio δ AB .

[0066] Figure 8 for Figure 7 The electric field simulation diagram of the support frame 30 is shown by Figure 8 It can be seen that the electric field is more concentrated in the lower part of the support frame 30 (including the A2 area where the second electrode group 34-2 is located and the B area where the conductive part 32 is located), and the energy distribution in the upper part of the support frame 30 (especially the A1 area where the first electrode group 34-1 is located) is extremely uneven. As a result, the ablation depth of the ablation catheter 100 cannot meet the design requirements well.

[0067] Fig.10 for Fig. 9 The electric field simulation diagram of the support frame 30 is shown by Fig.10 It can be seen that the electric field is roughly evenly distributed in the upper and lower parts of the support frame 30. In particular, due to the electrode spacing between the first electrode group 34-1 and the second electrode group 34-2 The reduction of the electrode distance Δ between the second electrode group 34-2 and the conductive portion 32 AB The increase compared to Figure 7 For the embodiment shown, the electric field distribution in the upper part of the support frame 30 (including the A region where the first electrode group 34-1 and the second electrode group 34-2 are located) is stronger, the energy is more concentrated, and the ablation depth can be improved. However, due to the reference electrode area S0 and the electrode surface area ratio δ AB The design is not reasonable enough, and the electric field distribution is also concentrated in the lower part of the support frame 30 (such as the area B where the conductive part 32 is located), which is unnecessary.

[0068] Fig.12 for Fig.11 The electric field simulation diagram of the support frame 30 is shown by Fig.12 It can be seen that the electric field is more concentrated in the lower part of the support frame 30. Among them, due to the reduction in the size of the second electrode group 34-2, the reference electrode area S0 is reduced and the electrode surface area ratio δ AB Reduced compared to Figure 7For the embodiment shown, the energy distribution in the upper part of the support frame 30 (especially the A1 area where the first electrode group 34-1 is located) is uneven. In addition, although the electric field distribution in the A2 area where the second electrode group 34-2 is located is relatively strong, the electric field distribution in the B area where the conductive part 32 is located is also relatively strong, which still cannot meet the design requirements well.

[0069] It can be clearly seen from the above three embodiments that the reference electrode area S0 of the support frame 30 and the electrode surface area ratio δ AB , electrode spacing Δ AB , Any factor in the above equation will affect the electric field distribution and thus the ablation depth. Figures 3 to 6 The curve relationship diagram between the ablation depth and the above-mentioned factors can be used to optimize the structure of the ablation catheter 100 , thereby improving the ablation depth of the ablation catheter 100 .

[0070] Fig.13 The ablation catheter 100 of the optimized embodiment is shown. Figure 7 The ablation catheter 100 of the illustrated embodiment, Fig.13 The size of the second electrode 34b in the ablation catheter 100 is reduced so that its electrode surface area S A2 smaller than the electrode surface area S of the first electrode 34a A1 , and the electrode surface area S of the electrode group 34 as a whole A Reduce; increase the electrode surface area S of the conductive portion 32 B , and S A The reduced value is less than S B The value of the increase makes the overall reference electrode area S0 increase and the electrode surface area ratio δ AB At the same time, the first electrode 34a is as close to the distal end of the support frame 30 as possible, and the second electrode 34b is closer to the first electrode 34a. The first electrode 34a and the second electrode 34b are distributed in the upper half of the support frame 36, that is, between the outermost end of the support frame 36 in the radial direction and the farthest end of the support frame 36 in the axial direction. The outermost end of the support frame 36 in the radial direction refers to the position point of the support frame 36 farthest from the axis of the catheter body 10 in the radial direction. In this way, the electrode spacing between the first electrode 34a and the second electrode 34b of the electrode group 34 is reduced. Reduce the electrode spacing Δ between the electrode group 34 and the conductive part 32 AB Increase, optionally, Less than Δ AB .

[0071] Fig.14 Shows Fig.13From the electric field simulation diagram of the ablation catheter 100 shown, it can be clearly seen that the electric field is more concentrated in the upper half of the support frame 30 (i.e., area A where the electrode group 34 is located), while also reducing the electric field distribution in non-essential positions (i.e., area B where the conductive portion 32 is located), thereby making the ablation energy more precise and increasing the ablation depth of the electrode group 34.

[0072] According to the reference electrode area S0, the electrode surface area ratio δ AB , electrode spacing Δ AB The correlation between the optimization of ablation depth and the changes in various factors can be summarized as follows:

[0073]

[0074] Among them, Δ 深 Indicates the difference in ablation depth; Represents the electrode surface area ratio δ AB α is the change in electrode surface area ratio Proportional coefficient affecting ablation depth; represents the change in the reference electrode area S0, and β is the change in the reference area Proportional coefficient affecting ablation depth; Δ d Indicates the comprehensive electrode spacing Δ AB The change in the distance between electrodes is -k, which indicates the change in the distance between electrodes. d The effect on ablation depth is negatively correlated.

[0075] when Δ d When determining, the degree of increase Δ of the ablation depth of the support frame 30 can be calculated according to the above composite formula 深 ,like is 20%, is 25%, Δ d When the ablation depth is -15%, the ablation depth is increased by approximately 30%-35%. According to the above composite formula, the ablation depth increased by optimizing one or two factors is less than the ablation depth increased by optimizing three factors, that is, optimizing each factor at the same time can obtain a better ablation depth. AB and the electrode spacing Δ AB , One or more of the above are optimized to improve the ablation depth. The electrode design is simpler, the operating space is larger, and it has been proven that it can effectively improve the ablation depth, thereby effectively improving the ablation effect.

[0076] In one embodiment, please refer to Figure 1 and Figure 2 The bearing frame 36 includes a plurality of bearing rods 361, and the plurality of bearing rods 361 are arranged around the central axis of the support frame 30 at circumferential intervals. The distal ends of the plurality of bearing rods 361 converge and connect together, and the proximal ends of the plurality of bearing rods 361 also converge and connect together, and connect to the distal end of the catheter body 10. In this embodiment, the bearing rods 361 are arc-shaped, and the plurality of bearing rods 361 are spherical as a whole. The number of the plurality of bearing rods 361 used in the support frame 30 can be two, four, six, eight, ten, twelve or any other suitable number. In this embodiment, the number of the bearing rods 361 is six. The plurality of bearing rods 361 can be evenly or unevenly distributed at circumferential intervals.

[0077] In some embodiments, the bearing rod 361 may also be in a spiral shape or other curve shape. The spiral bearing rod 361 may be obtained by heat setting after cutting, or the bearing rod 361 may be formed into the above spiral structure by rotating during implantation.

[0078] Each electrode group 34 includes a plurality of electrodes, and the plurality of electrodes are respectively arranged on the bearing rod 361. Exemplarily, in this embodiment, the plurality of electrodes include a plurality of first electrodes 34a and a plurality of second electrodes 34b, and a first electrode 34a and a second electrode 34b are arranged on each bearing rod 361. It is understandable that the number of electrodes on the bearing rod 361 can also be reasonably set according to actual conditions. The position of the bearing rod 361 that is farthest from the central axis L of the catheter body 10 in the radial direction is called the outermost end. In this embodiment, the first electrode 34a and the second electrode 34b are arranged between the outermost end and the farthest end of the bearing rod 361, so as to ensure that the electrodes can better conform to the atrial tissue and maintain good wall adhesion.

[0079] The first electrode 34a and the second electrode 34b are both made of platinum-iridium alloy, gold alloy, stainless steel, nickel-titanium or any other biocompatible medical metal. The first electrode 34a and the second electrode 34b can be ring electrodes, sheet electrodes, point electrodes or spherical electrodes, etc., which are not specifically limited in this embodiment.

[0080] The connection frame 38 is a grid structure in which multiple pillars are connected end to end. The proximal end of the grid structure is connected to the distal end of the catheter body 10, and the distal end of the grid structure is connected to the proximal ends of the plurality of bearing rods 361. The grid structure helps to improve the supporting performance of the support frame 30. The electrode surface area of ​​the conductive part 32 is the sum of the surface areas of the multiple pillars, and the surface area of ​​each pillar is the product of its length and width.

[0081] In one embodiment, see Figure 2The grid structure of the connecting frame 38 includes a plurality of grid groups 381, and the plurality of grid groups 381 are circumferentially arranged around the central axis of the supporting frame 30. The distal end of each grid group 381 is connected to the proximal end of a supporting rod 361, and the proximal end of each grid group 381 is connected to the distal end of the catheter body 10. Two adjacent grid groups 381 in the circumferential direction are connected to each other on the supporting frame 30 by at least one connecting grid 382.

[0082] In the present embodiment, each grid group 381 includes two main grids, namely a first main grid 383 and a second main grid 385. The first main grid 383 and the second main grid 385 are arranged along the axial direction, and the two share a grid node. The distal end of the first main grid 383 is connected to the proximal end of the load-bearing rod 361, and the proximal end of the second main grid 385 is connected to the distal end of the catheter body 10. The second main grids 385 of two adjacent grid groups 381 reuse one side, and the first main grids 383 of two adjacent grid groups 381 are connected by a connecting grid 382. The outlines of the main grids 383 and 385 are both polygonal, and can be specifically quadrilateral. The second main grid 385 opens toward one side of the catheter body 10.

[0083] Each connection grid 382 includes two subgrids, namely a first subgrid 384 and a second subgrid 386, which are arranged in the circumferential direction and reuse one side. In two adjacent grid groups 381, the first subgrid 384 reuses one side with the first main grid 383 and the second main grid 385 in one adjacent grid group 381, and the second subgrid 386 reuses one side with the first main grid 383 and the second main grid 385 in the other adjacent grid group 381. The outlines of the subgrids 384 and 386 are both polygonal, and can be quadrilaterals.

[0084] In some embodiments, adjacent grid groups 381 may be directly connected to each other, so that the connecting grid 382 is not required; alternatively, the grid group 381 may be a single main grid or multiple main grids; alternatively, the connecting grid 382 may be a single sub-grid or multiple sub-grids, and is not limited to the illustrated embodiments.

[0085] In this embodiment, the connection frame 38 is constructed as a dense grid structure, and the connection frame 38 is constructed as a conductive part 32 as a whole. The conductive part 32 has a larger electrode surface area as a whole. Therefore, under the same voltage, the current density of the conductive part 32 is smaller, and the energy distribution in the area where the conductive part 32 is located is less.

[0086] When the ablation catheter 100 of this embodiment is used to transmit ablation energy to the target tissue area, it can be achieved through the cooperation of the electrode group 34 and the conductive part 32 of the support frame 30. Specifically, the electrode included in the electrode group 34 is connected to an output terminal of the energy generator, and the conductive part 32 is connected to another output terminal of the energy generator, thereby forming a pulsed electric field to transmit ablation energy to the target tissue area. Since the support frame 30 is a cage-like structure as a whole, the first electrode 34a and the second electrode 34b on the carrier frame 36 can be regarded as local point ablation when discharging. Circular ablation can be achieved by connecting multiple first electrodes 34a or multiple second electrodes 34b that are distributed in a ring shape point by point, which is particularly suitable for ablation surgery on the tricuspid isthmus, the top of the left atrium, the bottom of the left atrium, the isthmus of the mitral valve, etc. in the treatment of arrhythmias.

[0087] In one embodiment, see Figure 1 to Figure 2 A traction tube 20 is movably disposed in the catheter body 10, and the distal end of the traction tube 20 can extend outward relative to the distal end of the catheter body 10. The distal ends of a plurality of bearing rods 361 converge and are connected to the distal end of the traction tube 20. Since the distal end of the support frame 30 is converged at the distal end of the traction member 20, and the traction member 20 is disposed in the catheter body 10 and connected to the handle, the traction member 20 can be used to control the contraction and expansion of the support frame 30.

[0088] The traction tube 20 can move relative to the catheter body 10 along its axial direction, so that the axial size and radial size of the support frame 30 change, thereby matching the size of the target ablation tissue area. Specifically, when the traction tube 20 moves toward the proximal end relative to the catheter body 10, the support frame 30 is compressed in the axial direction, its axial size decreases, and its radial size increases accordingly; when the traction tube 20 moves toward the distal end relative to the catheter body 10, the support frame 30 is stretched in the axial direction, its axial size increases, and its radial size decreases accordingly.

[0089] By flexibly adjusting the outer diameter of the support frame 30 through the traction tube 20, the support frame 30 can adapt to blood vessels (such as pulmonary veins) or other body tissues of different diameters, and can ablate the target ablation area under any appropriate outer diameter condition, rather than limiting the support frame 30 to ablate under the condition of the maximum axial compression, thereby improving the adaptability to the anatomical morphology of different target ablation areas, facilitating the operation of the ablation device, and achieving a good ablation effect. On the other hand, by adjusting the outer diameter of the support frame 30 through the traction tube 20 to reduce its outer diameter, the sheathing and unsheathing operations of the support frame 30 can be facilitated, and the recovery and release operations are faster and more convenient. At the same time, damage to the support rod 361 and the electrodes arranged on the support rod 361 during the sheathing process can be avoided.

[0090] In some embodiments, the traction tube 20 can also be omitted, that is, the ablation catheter 100 can be provided with no traction tube 20, and the support frame 30 expands radially in a self-expanding manner. At this time, the diameter of the support frame 30 after expansion is not adjustable, and it can be applied to ablation targets of fixed size areas. In addition, for the structure with the traction tube 20 in this embodiment, the expansion degree of the support frame 30 can be adjusted by manipulating the traction tube 20 so as to better fit the human tissue.

[0091] The traction tube 20 can be a steel cable, a flexible polyimide tube, a fluoropolyethylene tube, a stainless steel tube, or other polymer materials. When the traction tube 20 is a tubular structure, the traction tube 20 has a certain structural strength, so that it can buffer the external force on the load-bearing rod 361 and effectively ensure the stability of the position of the load-bearing rod 361. In some embodiments, a mapping electrode 39 is also provided on the load-bearing rod 361. The mapping electrode 39 can be single or multiple. When in use, it is close to the tissue cells of the target ablation site to detect the electrophysiological signals of the tissue cells, such as electrocardiogram signals. Schematically, there are multiple mapping electrodes 39 in this embodiment. The load-bearing rod 361 includes a plurality of first load-bearing rods 361a and a plurality of second load-bearing rods 361b alternately arranged in the circumferential direction, and the mapping electrode 39 is arranged on each first load-bearing rod 361a or each second load-bearing rod 361b. That is, the mapping electrodes 39 are arranged on non-adjacent supporting rods 361. The advantage of this arrangement is that, compared with arranging the mapping electrodes 39 on each supporting rod 361, firstly, the number of mapping electrodes 39 will be relatively reduced, which means that the number of wires of the mapping electrodes 39 will be less, which is more conducive to the assembly process. Secondly, the mapping electrodes 39 are arranged on non-adjacent supporting rods 361, and the number of the marking electrodes 39 is sufficient to map multiple different positions in the circumferential direction, meeting the mapping requirements in the ablation operation. Schematically, the mapping electrode 39 is located between the second electrode 34b and the connecting frame 38 and is closer to the proximal end of the supporting frame 36. This arrangement can ensure that even when the ablation catheter 100 is attached to the myocardial tissue, the electrocardiogram signal of the myocardium can be accurately mapped, thereby improving the mapping effect.

[0092] In some embodiments, the electrode length of the mapping electrode 39 is smaller than the electrode length of the first electrode 34a and the second electrode 34b. This is because if the electrode length of the mapping electrode 39 is too long, the potential signal collected by the mapping electrode 39 will be inaccurate, affecting the operator's judgment.

[0093] In some embodiments, a reference electrode 37 is also provided on the tube wall of the catheter body 10 and / or the traction tube 20, and the connection method of the reference electrode 37 includes but is not limited to welding, clamping, bonding, integral molding, etc. Schematically, the number of reference electrodes 37 includes three, of which two reference electrodes 37 are provided on the catheter body 10 and are spaced apart in the direction of the central axis L of the catheter body 10, and the remaining reference electrode 37 is provided on the traction tube 20. It should be noted that the number of reference electrodes 37 is only used for illustration, and the embodiment of the present application does not make specific restrictions. For example, the number of reference electrodes 37 can also be set according to actual needs. In this embodiment, the reference electrode 37 is a ring electrode. In some other embodiments, the reference electrode 37 can also be a sheet electrode, a point electrode, etc., which are not specifically limited in the embodiment of the present application.

[0094] The reference electrode 37 may be made of metal materials such as platinum, iridium, gold, silver, etc. The axial length of the reference electrode 37 may be 1.2 mm. It should be noted that the size of the reference electrode 37 is only for illustration and does not constitute a specific limitation.

[0095] The first function of the reference electrode 37 is to act as a reference electrode, that is, to be used for ECG signal mapping to obtain a reference potential. Specifically, the electrode group 34 on the carrier frame 36 can be well attached to the target tissue area to act as a mapping electrode to map the ECG signal of the target tissue area and obtain the potential. Although the reference electrode 37 is not attached to the myocardial tissue, it can also obtain the reference potential from the fluid in contact with the reference electrode 37, and then can obtain a more accurate ECG signal based on the difference between the reference potential obtained by the reference electrode 37 and the potential obtained by the electrode group 34, thereby improving the accuracy of the mapping. The second function of the reference electrode 37 is to act as a positioning electrode for the three-dimensional mapping system, that is, it is used to display the body of the catheter body 10 / traction tube 20 during the three-dimensional modeling process.

[0096] It should be noted that the above embodiments only express the preferred implementation of the present application, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the present application. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, such as combining different features in various embodiments, etc., which should all fall within the scope of protection of the present application.

Claims

1. An ablation catheter, characterized in that: include: a catheter body; as well as A support frame is arranged at the distal end of the catheter body, the support frame comprises a connecting frame and a bearing frame, the bearing frame is arranged at the distal end relative to the connecting frame, the distal end of the connecting frame is connected to the proximal end of the bearing frame, the proximal end of the connecting frame is connected to the distal end of the catheter body, the connecting frame is provided with a conductive part, the bearing frame is provided with an electrode group insulated from the conductive part, the conductive part and the electrode group are respectively used to connect two output terminals of an energy generator to transmit the ablation energy output by the energy generator to the target tissue area; The sum of the electrode surface area of ​​the electrode group and the electrode surface area of ​​the conductive portion is used as the reference electrode area, and the reference electrode area is within a preset range; And / or, the electrode surface area of ​​the electrode group is smaller than the electrode surface area of ​​the conductive portion; and / or, when there are at least two electrode groups along the axial direction of the supporting frame, the electrode spacing between the conductive portion and an adjacent electrode group is greater than the electrode spacing between two adjacent electrode groups.

2. The ablation catheter according to claim 1, characterized in that: When the reference electrode area is within the preset range, the preset range is (0, 500 mm 2 ].

3. The ablation catheter according to claim 1, characterized in that: When at least two electrode groups are provided along the axial direction of the carrying frame, the electrode spacing between the conductive portion and an adjacent electrode group is Δ AB , where 2mm<Δ AB <20mm.

4. The ablation catheter according to claim 1, characterized in that: When at least two electrode groups are provided along the axial direction of the supporting frame, the electrode spacing between two adjacent electrode groups in the electrode group is in 5. The ablation catheter according to claim 1, characterized in that: When the conductive part and the electrode group are respectively connected to two output terminals of the energy generator, the electric field strength of the area where the conductive part is located is smaller than the electric field strength of the area where the electrode group is located.

6. The ablation catheter according to claim 1, characterized in that: The electrode groups are provided with two along the axial direction of the supporting frame, namely a first electrode group and a second electrode group, wherein the first electrode group is provided at a distal end relative to the second electrode group; and the electrode spacing between the conductive part and the second electrode group is greater than the electrode spacing between the first electrode group and the second electrode group.

7. The ablation catheter according to claim 6, characterized in that: The first electrode group includes a plurality of first electrodes, and the second electrode group includes a plurality of second electrodes; the plurality of first electrodes are arranged at intervals around the central axis of the support frame to form a first ring, and the plurality of second electrodes are arranged at intervals around the central axis of the support frame to form a second ring, and the plane where the first ring is located and the plane where the second ring is located are both perpendicular to the central axis of the support frame.

8. The ablation catheter according to claim 7, characterized in that: The connection frame is integrally constructed as the conductive portion, and a distance between any second electrode and the farthest end of the connection frame in its axial extension direction is greater than a distance between any first electrode and a second electrode in its axial extension direction.

9. The ablation catheter according to claim 6, characterized in that: The sum of electrode surface areas of the plurality of second electrodes is smaller than the sum of electrode surface areas of the plurality of first electrodes.

10. The ablation catheter according to claim 1, characterized in that: The supporting frame includes a plurality of supporting rods, which are arranged at intervals around the central axis of the supporting frame, the proximal ends of the supporting rods are connected to the distal ends of the connecting frame, and the distal ends of the supporting rods are converged into one, and the electrode group includes a plurality of electrodes arranged on the supporting rods at intervals around the central axis of the supporting frame. 11 . The ablation catheter according to claim 10 , wherein at least two electrode groups are provided, and at least two electrodes are provided on each of the supporting rods.

12. The ablation catheter according to claim 10, characterized in that: The support rod has an outermost end which is farthest from the central axis of the catheter body in radial direction; the plurality of electrodes included in the electrode group are all located between the outermost end of the support rod and the farthest end of the support rod.

13. The ablation catheter according to any one of claims 1 to 12, characterized in that: The connection frame is a grid structure with multiple pillars connected end to end. The proximal end of the grid structure is connected to the distal end of the catheter body, and the distal end of the grid structure is connected to the proximal end of the supporting frame.

14. The ablation catheter according to claim 13, characterized in that: The electrode surface area of ​​the conductive part is the sum of the surface areas of the plurality of pillars, and the surface area of ​​each pillar is the product of the length and width of each pillar.

15. The ablation catheter according to claim 13, characterized in that: The grid structure includes a plurality of grid groups, which are arranged circumferentially around the central axis of the support frame, the distal end of each grid group is connected to the proximal end of the carrier frame, the proximal end of each grid group is connected to the distal end of the catheter body, and two adjacent grid groups are connected to each other in the circumferential direction of the support frame.

16. The ablation catheter according to claim 15, characterized in that: The grid structure further includes a plurality of connecting grids, and two adjacent grid groups are connected in the circumferential direction of the supporting skeleton by at least one connecting grid.

17. The ablation catheter according to claim 16, characterized in that: Each of the grid groups includes at least one main grid, at least one connecting grid is arranged between two adjacent grid groups, at least one connecting grid reuses one side with each main grid in two adjacent grid groups, and the outlines of the main grid and the connecting grid are both polygonal.

18. The ablation catheter according to claim 16, characterized in that: Each of the grid groups includes a first main grid and a second main grid, the first main grid and the second main grid share a grid node, and the second main grids of two adjacent grid groups reuse one side; The distal end of the first main grid is connected to the proximal end of the carrier frame, the second main grid is a polygon opening toward the catheter body, and the proximal end of the second main grid is connected to the distal end of the catheter body; A connection grid is provided between two adjacent grid groups, and the connection grid reuses one side with each of the first main grids and each of the second main grids in the two adjacent grid groups.

19. The ablation catheter according to claim 18, characterized in that: The connected grid includes a first sub-grid and a second sub-grid, the first sub-grid and the second sub-grid reuse one side, the first sub-grid and the first main grid and the second main grid in one of the adjacent grid groups reuse one side respectively, and the second sub-grid and the first main grid and the second main grid in another adjacent grid group reuse one side respectively.

20. The ablation catheter according to claim 10, characterized in that: The ablation catheter further comprises a mapping electrode disposed on the supporting rod; the mapping electrode is disposed at the proximal end relative to the electrode group.

21. The ablation catheter according to claim 20, characterized in that: The plurality of supporting rods include a plurality of first supporting rods and a plurality of second supporting rods, and the plurality of first supporting rods and the plurality of second supporting rods are alternately arranged around the central axis of the supporting frame; there are a plurality of mapping electrodes, and at least one mapping electrode is provided on each of the first supporting rods or each of the second supporting rods, and the mapping electrodes are used to detect electrophysiological signals of the target tissue area.

22. The ablation catheter according to claim 20, characterized in that: The electrode length of the mapping electrode is smaller than the length of the electrode included in the electrode group.

23. The ablation catheter according to claim 10, characterized in that: The ablation catheter further comprises a traction tube, which is passed through the catheter body and has a distal end extending out of the distal end of the catheter body. The distal ends of the plurality of bearing rods are connected to the distal end of the traction tube.

24. The ablation catheter according to claim 23, characterized in that: A reference electrode is arranged on the outer wall of the catheter body and / or the traction tube, and the reference electrode is used for mapping the electrocardiogram signal to obtain a reference potential.

25. The ablation catheter according to claim 1, characterized in that: The ablation depth of the ablation catheter is positively correlated with the reference electrode area; The ablation depth of the ablation catheter is positively correlated with the electrode spacing between the conductive portion and an adjacent electrode group; When at least two electrode groups are provided along the axial direction of the carrying frame, the ablation depth of the ablation catheter is negatively correlated with the electrode spacing between two adjacent electrode groups; The ablation depth of the ablation catheter is positively correlated with the electrode surface area ratio, and the electrode surface area ratio is the ratio of the electrode surface area of ​​the electrode group to the electrode surface area of ​​the conductive part.

26. The ablation catheter according to claim 1, characterized in that The bearing frame and the connecting frame are an integrated structure cut from elastic metal pipes.

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