A pulse ablation catheter

Abstract

The present invention belongs to the technical field of ablation catheters, and specifically relates to a pulse ablation catheter, which includes a handle assembly, a catheter assembly, and a pulse electrode assembly; the handle assembly includes a first adjustment wheel, an anti-slip handle, and a second adjustment wheel arranged in sequence from one end to the other end, and the first adjustment wheel is rotatably connected to one end of the anti-slip handle. The present invention enables the device to adjust the length and diameter of the flexible circuit board according to the shape of the target tissue by rotating the first adjustment wheel and the second adjustment wheel, so that the ablation electric field can better adapt to the target tissue, avoiding problems such as inability to completely ablate the entire area and insufficient ablation area. At the same time, through the cooperation of the first pointer and the first variable mark, the second pointer and the second variable mark, and the mark surface and the third variable mark, the operator can quickly and accurately obtain the diameter change and length change of the flexible circuit board driven by the second adjustment wheel.

Description

Technical Field

[0001] The present invention belongs to the technical field of ablation catheters, and in particular relates to a pulse ablation catheter. Background Art

[0002] In the field of electrophysiological treatment, it is common to use pulse ablation catheters to transfer energy and perform tissue ablation. Pulse ablation is an effective method for treating persistent atrial fibrillation, ventricular arrhythmias, diabetes, and chronic bronchitis. The ablation electrode is delivered to the lesion area through the blood vessels, and the ablation electrode is used to apply an ablation electric field to the target area. The ablation electric field is applied to the lesion to form pores on the cell membrane of the target cell, thereby destroying the cell stability and causing the target cell to apoptosis. Compared with traditional radiofrequency ablation and cryoablation techniques, pulse ablation has shown many advantages, including selective destruction of tissues, non-thermal ablation mechanism, rapid energy release, good damage effect and shortened operation time, making it a highly potential next-generation ablation energy technology.

[0003] At present, the electrode designs on common pulse ablation catheters are diverse, including ring electrodes, strip-shaped cage electrodes, mesh cage electrodes, and expandable balloon electrodes. However, the above-mentioned electrodes still have defects to varying degrees during the ablation process:

[0004] 1. Although the ring electrode has a simple structure, it is difficult to adjust the expansion degree, and the operator's skills are required to be high, and the ideal ablation effect may not be achieved; although the strip ball cage electrode is easy to fold, it may cause accidental contact with adjacent electrodes during operation, resulting in sparking; although the mesh ball cage electrode is stable, when released from the delivery catheter, the fast or over-expanded ball electrode may cause damage to human tissue. At the same time, when it is retracted into the catheter after surgery, it is difficult to retract due to excessive or too fast traction of the inner tube; the inflatable balloon electrode may block the trachea or blood vessels when inflated, which is not only not conducive to tissue blood and gas exchange, but also affects the heat dissipation of the target tissue for ablation;

[0005] 2. Different lesion areas have different shapes. The ablation components in the prior art cannot form an effective contact with the lesion area, resulting in poor contact, insufficient electric field, and the ablation area cannot match the lesion area (for example, when ablation is performed using a ring electrode, a strip ball cage electrode, or a mesh ball cage electrode, when the diameter of the ablation area is reduced according to the lesion area, the length of the ablation area will inevitably increase; or, when the length of the ablation area is increased, the ablation diameter will inevitably decrease), resulting in problems such as inability to completely ablate the entire circumference and insufficient ablation surface. The operator needs to constantly adjust the contact angle to find a better contact position, which makes the operation difficult and takes a long time, increasing the risk of the operation;

[0006] 3. In the existing technical architecture, pulse ablation equipment focuses on realizing pulse ablation function and performing targeted treatment on target tissues. However, when radiofrequency ablation is required on target tissues, the current equipment needs to be replaced, that is, the pulse generating device is replaced with a radiofrequency generating device. This operation process is not only cumbersome, but also limits the versatility and application scope of the equipment. In view of this, the scope of application of the equipment still needs to be further expanded and optimized to meet a wider range of clinical needs.

[0007] Based on the above content, this application document proposes a pulse ablation catheter to improve the above problems. Summary of the invention

[0008] The purpose of the present invention is to provide a pulse ablation catheter. By rotating the first adjustment wheel and the second adjustment wheel, the device can adjust the length and diameter of the flexible circuit board according to the shape of the target tissue, so that the ablation electric field can better adapt to the target tissue, avoiding problems such as incomplete ablation and insufficient ablation area. At the same time, through the coordination of the first pointer and the first variable identifier, the second pointer and the second variable identifier, and the identification surface and the third variable identifier, the operator can quickly and accurately obtain the diameter change and length change of the flexible circuit board driven by the second adjustment wheel.

[0009] The technical solution adopted by the present invention is as follows:

[0010] A pulse ablation catheter comprises a handle assembly, a catheter assembly and a pulse electrode assembly;

[0011] The handle assembly comprises a first adjusting wheel, an anti-slip handle and a second adjusting wheel which are arranged in sequence from one end to the other end, wherein the first adjusting wheel is rotatably connected to one end of the anti-slip handle, and the second adjusting wheel is threadedly connected to the other end of the anti-slip handle;

[0012] The catheter assembly comprises an outer catheter and an inner catheter coaxially arranged from outside to inside, the outer catheter is fixed to one end of the first adjusting wheel, the inner catheter is fixed to one end of the second adjusting wheel, and the inner catheter can move along the axis of the outer catheter;

[0013] The pulse electrode assembly includes a flexible circuit board, which is installed between the outer catheter and the inner catheter. A plurality of ablation electrodes are arranged on the surface of the flexible circuit board. In an initial state, the flexible circuit board is spirally wound around the outer sides of the outer catheter and the inner catheter. Through the cooperation of the outer catheter and the inner catheter, the flexible circuit board can be switched between a contracted state, a first expanded state and a second expanded state. In an initial state, the flexible circuit board is in a contracted state.

[0014] The diameter of the flexible circuit board can be adjusted by the first adjusting wheel, and the length and diameter of the flexible circuit board can be adjusted by the second adjusting wheel.

[0015] In a preferred embodiment, the pulse electrode assembly further comprises a first fixing element and a second fixing element, wherein the first fixing element is fixed to one end of the outer catheter away from the handle assembly, the second fixing element is fixed to one end of the inner catheter away from the handle assembly, and the flexible circuit board and the first fixing element as well as the flexible circuit board and the second fixing element are all fixedly connected.

[0016] In a preferred embodiment, the flexible circuit board includes a first protective layer, a second protective layer, a first electrode, a second electrode, a plurality of first temperature sensors and a plurality of second temperature sensors, the first protective layer and the second protective layer are both fixed between the flexible circuit board and a first fixing element, the first electrode and the second electrode are arranged on the surface of the first protective layer, and the plurality of first temperature sensors and the plurality of second temperature sensors are both assembled between the first protective layer and the second protective layer.

[0017] In a preferred embodiment, a stop groove is provided inside the first adjusting wheel at one end close to the second adjusting wheel, and a first pointer is slidably connected inside the stop groove. A spiral groove and a plurality of first variable identifiers are provided on the outer end of the anti-slip handle close to the first adjusting wheel, and the plurality of first variable identifiers are evenly distributed in a spiral shape on the outer side of the anti-slip handle, and the first pointer and the spiral groove, as well as the first pointer and the first variable identifier, are adapted to each other.

[0018] In a preferred embodiment, one end of the second adjustment wheel close to the first adjustment wheel is marked as an identification surface, a second pointer is fixed to one end of the identification surface, and a plurality of second variable identifications and a plurality of third variable identifications are provided at one end of the outer side of the anti-slip handle close to the second adjustment wheel. The plurality of second variable identifications are evenly distributed along the axial direction of the anti-slip handle, and the plurality of third variable identifications are evenly distributed in a spiral shape on the outer side of the anti-slip handle, and the second pointer and the second variable identification as well as the identification surface and the third variable identification are all adapted to each other.

[0019] In a preferred embodiment, the outer catheter and the inner catheter are made of any one of the following materials: PRBAX, polytetrafluoroethylene, and PA.

[0020] In a preferred embodiment, the material of the first electrode and the second electrode is any one of the following materials: copper foil, conductive silver ink, conductive silver paste.

[0021] A method for using a pulse ablation catheter, applicable to any of the pulse ablation catheters described above, comprises the following steps:

[0022] Stp1: Rotate the first adjusting wheel to drive the outer guide tube and the rear end of the flexible circuit board to rotate, thereby adjusting the diameter of the flexible circuit board while keeping the length unchanged;

[0023] Stp2: Read the diameter change of the flexible circuit board through the cooperation of the first pointer and the first variable identifier;

[0024] Stp3: Rotate the second adjusting wheel to drive the inner catheter and the front end of the flexible circuit board to rotate, and synchronously adjust the diameter and length of the flexible circuit board;

[0025] Stp4: Through the coordination of the second pointer, the second variable identifier and the third variable identifier, the diameter change and length change of the flexible circuit board are read.

[0026] A pulse ablation system, comprising a power supply module, a pulse generation module, an impedance detection module, a control module, a temperature acquisition module and a pulse ablation catheter as described in any one of the above, wherein a plurality of pulse electrodes are arranged inside the pulse ablation catheter, and the power supply module and the control module, the power supply module and the pulse generation module, the pulse generation module and the impedance monitoring module, and the pulse generation module and the ablation catheter are all electrically connected;

[0027] The power supply module is used to provide electrical energy;

[0028] The pulse generating module is used to send a pulse signal to the pulse ablation catheter;

[0029] The impedance detection module is used to detect the impedance value between the plurality of pulse electrodes of the electrode, and then determine the impedance value of the target tissue;

[0030] The control module can receive the impedance value of the target tissue detected by the impedance detection module, and determine the ablation parameters according to the impedance value of the target tissue, wherein the ablation parameters at least include: ablation time, pulse voltage, pulse width and pulse frequency;

[0031] The temperature acquisition module is used to acquire the real-time temperature value of the target tissue;

[0032] The pulse ablation catheter is used for performing pulse ablation on target tissue.

[0033] The technical effects achieved by the present invention are:

[0034] The present invention rotates the first adjusting wheel so that the first adjusting wheel drives the rear end of the outer catheter and the flexible circuit board to rotate, so that the diameter of the flexible circuit board changes while the length remains unchanged. The second adjusting wheel is rotated so that the first adjusting wheel drives the front end of the inner catheter and the flexible circuit board to rotate, so as to adjust the diameter and length of the flexible circuit board. Through the cooperation of the first adjusting wheel and the second adjusting wheel, the device can adjust the length and diameter of the flexible circuit board respectively according to the shape of the target tissue, so that the flexible circuit board can be completely attached to the target tissue, and the ablation electric field formed by the first electrode and the second electrode can better adapt to the target tissue, avoiding the problems of inability to completely ablate the entire area and insufficient ablation area, thereby reducing the difficulty, operation time and operation risk of the pulse ablation operation, and at the same time, avoiding the shortcomings of various forms of electrodes in the prior art during use;

[0035] In the present invention, when the first adjusting wheel is rotated to adjust the diameter of the flexible circuit board, the first adjusting wheel drives the first pointer to rotate, and the first pointer cooperates with the first variable mark, so that the operator can quickly and accurately obtain the diameter change of the flexible circuit board driven by the first adjusting wheel. When the length and diameter of the flexible circuit board are adjusted by the second adjusting wheel, the second adjusting wheel drives the second pointer to rotate, and the second pointer and the second variable mark as well as the mark surface and the third variable mark cooperate, so that the operator can quickly and accurately obtain the diameter change and length change of the flexible circuit board driven by the second adjusting wheel.

[0036] The present invention adjusts the voltage of the power supply module and the frequency of the pulse generator so that the pulse ablation catheter can be transformed from a pulse ablation state to a radiofrequency ablation state, thereby enabling the pulse ablation system to take into account both radiofrequency ablation and pulse ablation at the same time, and to achieve pulse and radiofrequency superposition ablation according to temperature and a predetermined time period, thereby improving the application scope of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the overall structure of the first embodiment of the present invention;

[0038] Figure 2 is a cross-sectional view of a handle assembly and a catheter assembly in Embodiment 1 of the present invention;

[0039] Figure 3 The present invention Figure 1 A local enlarged schematic diagram of the middle A;

[0040] Figure 4 is a schematic diagram of the structure of the pulse electrode assembly in the first embodiment of the present invention;

[0041] Figure 5 is a structural cross-sectional view of a flexible circuit board in Embodiment 1 of the present invention;

[0042] Figure 6 is a structural exploded diagram of the handle assembly in the first embodiment of the present invention;

[0043] Figure 7 is a structural cross-sectional view of the first adjusting wheel in the first embodiment of the present invention;

[0044] Figure 8 The present invention Figure 7 A partial enlarged schematic diagram of the middle B;

[0045] Fig. 9 is a cross-sectional schematic diagram of the inner catheter in the first embodiment of the present invention;

[0046] Fig.10 is a schematic diagram of the contracted state and expanded state of the flexible circuit board in the first embodiment of the present invention;

[0047] Fig.11 is a reference schematic diagram of a form of the first electrode and the second electrode in the first embodiment of the present invention;

[0048] Fig.12 is a reference schematic diagram of another form of the first electrode and the second electrode in the first embodiment of the present invention;

[0049] Fig.13 is a schematic diagram of the process of pulse ablation in the second embodiment of the present invention;

[0050] Fig.14 It is a schematic diagram of the process of radiofrequency ablation in the second embodiment of the present invention.

[0051] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0052] 10. Handle assembly;

[0053] 11. First adjustment wheel; 12. Anti-slip handle; 13. Second adjustment wheel; 14. First pointer; 15. Spiral slide; 16. First variable mark; 17. Second pointer; 18. Second variable mark; 19. Third variable mark;

[0054] 20. Catheter assembly;

[0055] 21. outer catheter; 22. inner catheter; 23. through hole; 24. electrode wire; 25. temperature sensing wire;

[0056] 30. Pulse electrode assembly;

[0057] 31. Flexible circuit board; 32. First fixing element; 33. Second fixing element; 34. First protective layer; 35. Second protective layer; 36. First electrode; 37. Second electrode; 38. First temperature sensor; 39. Second temperature sensor. DETAILED DESCRIPTION

[0058] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0059] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0060] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The phrase "in a preferred embodiment" that appears in different places in this specification does not refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0061] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0062] Embodiment 1

[0063] Please see attached Figures 1 to 3 As shown, it is a first embodiment of the present invention, which provides a pulse ablation catheter, including a handle assembly 10, a catheter assembly 20 and a pulse electrode assembly 30;

[0064] The handle assembly 10 includes a first adjusting wheel 11, an anti-slip handle 12, and a second adjusting wheel 13 which are arranged in sequence from one end to the other end. The first adjusting wheel 11 is rotatably connected to one end of the anti-slip handle 12, and the second adjusting wheel 13 is threadedly connected to the other end of the anti-slip handle 12. A blocking cap is fixed to the ends of the first adjusting wheel 11 and the second adjusting wheel 13 which are away from each other.

[0065] The catheter assembly 20 includes an outer catheter 21 and an inner catheter 22 which are coaxially arranged from outside to inside, and the inner catheter 22 extends to the outside of the outer catheter 21 from one end away from the handle assembly 10, the outer catheter 21 is fixed to one end of the first adjustment wheel 11, and the inner catheter 22 is fixed to one end of the second adjustment wheel 13, and the inner catheter 22 can move along the axis of the outer catheter 21, and the outer catheter 21 and the inner catheter 22 are clearance-matched;

[0066] The pulse electrode assembly 30 includes a flexible circuit board 31, which is assembled between the outer catheter 21 and the inner catheter 22. A plurality of ablation electrodes are arranged on the surface of the flexible circuit board 31. In the initial state, the flexible circuit board 31 is spirally wound around the outer sides of the outer catheter 21 and the inner catheter 22. Through the cooperation of the outer catheter 21 and the inner catheter 22, the flexible circuit board 31 can be switched between a contracted state, a first expanded state and a second expanded state. In the initial state, the flexible circuit board 31 is in a contracted state.

[0067] The diameter of the flexible circuit board 31 can be adjusted by the first adjusting wheel 11 , and the length and diameter of the flexible circuit board 31 can be adjusted by the second adjusting wheel 13 .

[0068] It should be noted that, since the flexible circuit board 31 is spirally wound around the outside of the outer catheter 21 and the inner catheter 22, the size of the flexible circuit board 31 in the unfolded state will not change. In order to better describe the working process of the present device, in this embodiment, there is a description of the "diameter of the flexible circuit board 31", which indicates the diameter of the flexible circuit board 31 in the spiral state, and there is a description of the "length of the flexible circuit board 31", which indicates the length of the flexible circuit board 31 in the extension direction of the inner catheter 22; further, the rotation direction in which the first adjusting wheel 11 is rotated to increase the diameter of the flexible circuit board 31 is recorded as a first expansion direction, and the direction in which the first adjusting wheel 11 is rotated to reduce the diameter of the flexible circuit board 31 is recorded as a first contraction direction, and the first expansion direction is opposite to the first contraction direction, and the second adjusting wheel 13 is rotated to increase the diameter of the flexible circuit board 31 and the length is recorded as a first contraction direction. The direction in which the diameter of the flexible circuit board 31 increases is recorded as the second expansion direction, and the direction in which the second adjusting wheel 13 is rotated to reduce the diameter and reduce the length of the flexible circuit board 31 is recorded as the second contraction direction, and the second expansion direction and the second contraction direction are opposite, wherein, if the first adjusting wheel 11 and the second adjusting wheel 13 rotate synchronously in the same direction, the outer catheter 21, the inner catheter 22 and the flexible circuit board 31 also rotate synchronously in the same direction, and the diameter and length of the flexible circuit board 31 will not change. Therefore, when the diameter of the flexible circuit board 31 needs to be increased, the first expansion direction and the second expansion direction are opposite in actual operation, and the specific rotation direction is operated according to the actual situation, and it does not constitute a specific limitation here; further, the end of the flexible circuit board 31 connected to the inner catheter 22 is recorded as the front end, and the end of the flexible circuit board 31 connected to the outer catheter 21 is recorded as the rear end.

[0069] Here, a pulse device is used in conjunction with the apparatus. The pulse device is electrically connected to the ablation electrode. The ablation signal provided by the pulse device is one of a high-voltage bidirectional pulse, a sine wave, and a cosine wave. An ablation electric field is formed between multiple ablation electrodes. Electroporation occurs in cell tissues under the action of the ablation electric field, thereby causing cell death or tissue damage to achieve ablation.

[0070] Specifically, an external thread column is integrally formed inside the second adjusting wheel 13, and an internal thread boss is provided at one end of the anti-slip handle 12 away from the first adjusting wheel 11, and the external thread column and the internal thread boss are adapted to each other, and the second adjusting wheel 13 and the anti-slip handle 12 are connected by the matching threads of the external thread column and the internal thread boss.

[0071] In this implementation, see Fig.10 As shown, when pulse ablation is performed on the target tissue in the patient's body, the pulse electrode assembly 30 is delivered to the lesion through the blood vessels through the cooperation of the imaging device, and the state of the flexible circuit board 31 is adjusted according to the size of the lesion. Fig.10 As shown at a in the figure, the length of the flexible circuit board 31 is substantially equal to the length of the target tissue. The operator holds the anti-slip handle 12 with his hand and rotates the first adjusting wheel 11, so that the first adjusting wheel 11 rotates along the first expansion direction. The first adjusting wheel 11 is fixedly connected to the outer catheter 21, so that the first adjusting wheel 11 drives the outer catheter 21 to rotate along the first expansion direction. Since the outer catheter 21 is connected to the rear end of the flexible circuit board 31, the rear end of the flexible circuit board 31 is driven by the outer catheter 21 to rotate relative to the anti-slip handle 12, so that the diameter of the flexible circuit board 31 increases (since the first adjusting wheel 11 and the outer catheter 21 only rotate relative to the anti-slip handle 12, at this time, the length of the flexible circuit board 31 remains unchanged) until the flexible circuit board 31 fits the target tissue (as shown in the figure). Fig.10 As shown in point b), the pulse device is started, and an ablation electric field is formed through multiple electrodes on the flexible circuit board 31 to perform complete circumferential ablation on the target tissue; if in the contracted state, the length of the flexible circuit board 31 is smaller than the length of the target tissue, the operator holds the anti-slip handle 12 with his hand, and rotates the second adjustment wheel 13, so that the second adjustment wheel 13 rotates along the second expansion direction. Since the second adjustment wheel 13 and the anti-slip handle 12 are threadedly connected, the second adjustment wheel 13 moves relative to the anti-slip handle 12 while rotating. Through the fixed connection between the second adjustment wheel 13 and the inner catheter 22, the second adjustment wheel 13 drives the inner catheter 22 to rotate along the second expansion direction. Since the inner catheter 22 is connected to the front end of the flexible circuit board 31, the front end of the flexible circuit board 31 is driven by the inner catheter 22 to rotate and move relative to the anti-slip handle 12, thereby increasing the length and diameter of the flexible circuit board 31 (as shown in FIG. Fig.10As shown at c in the figure, until the length of the flexible circuit board 31 matches the length of the target tissue. During this process, the diameter of the flexible circuit board 31 and the target tissue will present three states: first, when the flexible circuit board 31 and the target tissue are in contact, the ablation device is started to perform pulse ablation on the target tissue; second, when the flexible circuit board 31 fails to fit the target tissue, the first adjustment wheel 11 is rotated so that the first adjustment wheel 11 rotates along the first expansion direction until the flexible circuit board 31 and the target tissue are in contact (at this time, the length of the flexible circuit board 31 remains unchanged and the diameter increases); third, the flexible circuit board 31 has already fit the target tissue and has caused an impact on the target tissue. When squeezing is formed, the first adjusting wheel 11 is rotated to make the first adjusting wheel 11 rotate along the first contraction direction until the flexible circuit board 31 and the target tissue are in contact with each other without squeezing the target tissue (at this time, the length of the flexible circuit board 31 remains unchanged and the diameter becomes smaller). Through the above-mentioned scheme, the device can independently adjust the length and diameter of the flexible circuit board 31 according to the size of the target tissue, so that the flexible circuit board 31 can be completely close to the target tissue, and the ablation electric field formed by multiple electrodes can better adapt to the target tissue, avoiding the problems of incomplete circumference ablation and insufficient ablation area, thereby reducing the difficulty, duration and risk of pulse ablation surgery.

[0072] Next, please refer to Figure 4 The pulse electrode assembly 30 also includes a first fixing element 32 and a second fixing element 33. The first fixing element 32 is fixed to an end of the outer catheter 21 away from the handle assembly 10, and the second fixing element 33 is fixed to an end of the inner catheter 22 away from the handle assembly 10, and the flexible circuit board 31 and the first fixing element 32 as well as the flexible circuit board 31 and the second fixing element 33 are all fixedly connected.

[0073] In this embodiment, when a pulse ablation operation is performed on a patient, when the first adjusting wheel 11 is rotated, the first adjusting wheel 11 drives the outer catheter 21 to rotate through the fixed connection between the first adjusting wheel 11 and the outer catheter 21, and the outer catheter 21 and the first fixing element 32 are fixedly connected, and the flexible circuit board 31 and the first fixing element 32 are fixedly connected, so that the first adjusting wheel 11 drives the rear ends of the outer catheter 21 and the flexible circuit board 31 to rotate, thereby adjusting the diameter of the flexible circuit board 31, and when the second adjusting wheel 13 is rotated, the second adjusting wheel 13 drives the inner catheter 22 to rotate through the fixed connection between the second adjusting wheel 13 and the inner catheter 22, and the inner catheter 22 and the second fixing element 33 are fixedly connected, and the flexible circuit board 31 and the second fixing element 33 are fixedly connected, so that the second adjusting wheel 13 drives the front ends of the inner catheter 22 and the flexible circuit board 31 to rotate and move, thereby adjusting the diameter and length of the flexible circuit board 31.

[0074] Secondly, please refer to Figure 5 , Fig.11 and Fig.12 As shown, the flexible circuit board 31 includes a first protective layer 34, a second protective layer 35, a first electrode 36, a second electrode 37, a plurality of first temperature sensors 38 and a plurality of second temperature sensors 39, the first protective layer 34 and the second protective layer 35 are both fixed between the flexible circuit board 31 and the first fixing element 32, the first electrode 36 and the second electrode 37 are arranged on the surface of the first protective layer 34, the plurality of first temperature sensors 38 and the plurality of second temperature sensors 39 are both assembled between the first protective layer 34 and the second protective layer 35, and the first electrode 36 and the pulse device, the second electrode 37 and the pulse device, the first temperature sensor 38 and the pulse device, and the second temperature sensor 39 and the pulse device are all electrically connected.

[0075] Furthermore, the first temperature sensor 38 can monitor tissue temperature to determine the ablation result, and the second temperature sensor 39 can monitor the temperature of the first electrode 36 and the second electrode 37 to prevent the pulse electrode from being damaged due to excessive temperatures of the first electrode 36 and the second electrode 37 .

[0076] It should be noted that, in the initial state, the flexible circuit board 31 is a spiral structure, and the first protective layer 34 is located on the inner wall of the spiral structure. The material of the first protective layer 34 and the second protective layer 35 can be any one of the following substances: polyetheretherketone (PEEK), polyimide (PI) or other polymer materials with insulating properties. In the present embodiment, the material of the first protective layer 34 and the second protective layer 35 is preferably polyimide. The setting of the first protective layer 34 and the second protective layer 35 can isolate the first electrode 36 and the first temperature sensor 38 as well as the second electrode 37 and the first temperature sensor 38.

[0077] Here, the specific shapes of the first electrode 36 and the second electrode 37 and the distribution states of the first temperature sensor 38 and the second temperature sensor 39 can be referred to. Fig.11 and Fig.12 As shown, of course, the shapes of the first electrode 36 and the second electrode 37 and the distribution states of the first temperature sensor 38 and the second temperature sensor 39 can be adjusted according to the actual shapes, as long as the ablation electric field can be formed and the temperature of the target tissue can be obtained. Fig.11 and Fig.12 The contents are for illustration and reference only and do not constitute specific limitations.

[0078] Furthermore, the first temperature sensor 38 and the second temperature sensor 39 may be any one of the following elements: a thermistor, an infrared sensor or other structural elements capable of measuring temperature. In the present embodiment, the first temperature sensor 38 and the second temperature sensor 39 are preferably thermistors.

[0079] In this embodiment, the flexible circuit board 31 spirally wound around the outer side of the outer tube 21 and the inner tube 22 can control the flexible circuit board 31 to expand or contract quickly and conveniently through the cooperation of the first adjusting wheel 11 and the second adjusting wheel 13, and the first electrode 36 and the second electrode 37 distributed on the surface of the first protective layer 34 will not cause sparks due to the connection between adjacent electrodes during the expansion or contraction process. At the same time, the flexible circuit board 31 in the expanded state is hollow inside and will not cause blockage of the trachea and blood vessels. The flexible circuit board 31 in the present application document can effectively avoid or solve the shortcomings of ring electrodes, strip ball cage electrodes, mesh ball cage electrodes, and balloon electrodes during use.

[0080] In a specific embodiment, when the first temperature sensor 38 is a thermistor, an array structure is formed by multiple thermistors, and the resistance value of each thermistor changes with the temperature of its location. By measuring the resistance value of each thermistor, the temperature information of the corresponding location can be obtained, wherein the resistance value of the NTC (negative temperature coefficient) thermistor decreases with increasing temperature, while the opposite is true for the PTC (positive temperature coefficient) thermistor.

[0081] In another specific embodiment, when the first temperature sensor 38 is an infrared sensor, an array structure is formed by multiple infrared sensors to measure the temperature of the object surface without contact. Each infrared sensor can detect the infrared radiation emitted by the object surface within its field of view. By analyzing these radiation signals, the temperature distribution of the object surface can be inferred.

[0082] Next, please refer to Figures 6 to 8 A stop groove is provided at one end of the first adjusting wheel 11 near the second adjusting wheel 13, and a first pointer 14 is slidably connected inside the stop groove. A spiral groove 15 and a plurality of first variable marks 16 are provided at one end of the outer side of the anti-slip handle 12 near the first adjusting wheel 11, and the plurality of first variable marks 16 are evenly distributed in a spiral shape on the outer side of the anti-slip handle 12, and the first pointer 14 and the spiral groove 15 as well as the first pointer 14 and the first variable mark 16 are adapted to each other.

[0083] It should be noted that the spiral chute 15 is spiral in shape, a pin is provided at the lower end of one end of the first pointer 14, the pin is slidably connected to the inside of the spiral chute 15, and the first pointer 14 and the spiral chute 15 are slidably connected via the pin.

[0084] Here, the first variable identifier 16 is used to represent the diameter change of the flexible circuit board 31 driven by the first adjustment wheel 11. The specific corresponding relationship can be obtained through multiple tests and measurements, and no further details are given here.

[0085] In this embodiment, when the diameter of the flexible circuit board 31 is adjusted by the first adjusting wheel 11, the first adjusting wheel 11 is rotated, and the outer catheter 21 and the rear end of the flexible circuit board 31 are driven to rotate by the first adjusting wheel 11, thereby adjusting the diameter of the flexible circuit board 31. At the same time, through the sliding connection between the first adjusting wheel 11 and the first pointer 14, the first adjusting wheel 11 drives the first pointer 14 to rotate synchronously. Since the first pointer 14 and the spiral groove 15 are slidingly connected, the first pointer 14 rotates around the central axis of the anti-slip handle 12 while slidingly connected inside the spiral groove 15, thereby causing the first pointer 14 to move relative to the first adjusting wheel 11. Through the cooperation of the first pointer 14 and multiple first variable identifiers 16, the diameter change of the flexible circuit board 31 driven by the first adjusting wheel 11 can be conveniently read.

[0086] Please refer again Figure 2 , Figure 3 and Figure 6 As shown, one end of the second adjusting wheel 13 close to the first adjusting wheel 11 is marked as an identification surface, and a second pointer 17 is fixed to the end of the identification surface close to the first adjusting wheel 11. A plurality of second variable identifications 18 and a plurality of third variable identifications 19 are provided on the outer side of the anti-slip handle 12 close to the second adjusting wheel 13. The plurality of second variable identifications 18 are evenly distributed on the surface of the anti-slip handle 12 along the axial direction of the anti-slip handle 12, and the plurality of third variable identifications 19 are evenly distributed on the outer side of the anti-slip handle 12 in a spiral shape, and the second pointer 17 and the second variable identification 18 as well as the identification surface and the third variable identification 19 are adapted to each other.

[0087] It should be noted that since the second variable identifier 18 and the third variable identifier 19 overlap, in order to better distinguish the second variable identifier 18 from the third variable identifier 19, the surfaces of the second variable identifier 18 and the third variable identifier 19 are set with different colors. For example, the surfaces of multiple second variable identifiers 18 are red, and the surfaces of multiple third variable identifiers 19 are yellow. Of course, the specific colors can be adjusted according to usage requirements, as long as the purpose of distinguishing the second variable identifier 18 from the third variable identifier 19 can be achieved. This does not constitute a specific limitation.

[0088] Furthermore, the second variable identifier 18 is used to indicate the diameter change of the flexible circuit board 31 driven by the second adjustment wheel 13, and the third variable identifier 19 is used to indicate the length change of the flexible circuit board 31 driven by the second adjustment wheel 13. The specific correspondence can be obtained through multiple tests and measurements, and no further details are given here.

[0089] In this embodiment, when the length and diameter of the flexible circuit board 31 are adjusted by the second adjusting wheel 13, the second adjusting wheel 13 is rotated, and the front end of the inner catheter 22 and the flexible circuit board 31 are driven to rotate by the second adjusting wheel 13, thereby adjusting the length and diameter of the flexible circuit board 31. At the same time, through the fixed connection between the second adjusting wheel 13 and the second pointer 17, the second adjusting wheel 13 drives the second pointer 17 to rotate and move along the axial direction of the anti-slip handle 12. Through the cooperation of the second pointer 17 and the second variable identifier 18, the diameter change of the flexible circuit board 31 driven by the second adjusting wheel 13 can be conveniently read. Through the cooperation of the identification surface and the third variable identifier 19, the length change of the flexible circuit board 31 driven by the second adjusting wheel 13 can be conveniently read, thereby enabling the device to quickly and accurately adjust the length and diameter of the flexible circuit board 31.

[0090] Please refer again Fig. 9 A plurality of through holes 23 are provided inside the inner catheter 22, and electrode wires 24 and temperature sensing wires 25 are respectively installed inside the plurality of through holes 23. The first electrode 36 and the pulse device as well as the second electrode 37 and the pulse device are electrically connected through the electrode wires 24, and the first temperature sensor 38 and the pulse device as well as the second temperature sensor 39 and the pulse device are electrically connected through the temperature sensing wires 25.

[0091] It should be noted that a plurality of side holes are opened on the outer wall of the inner catheter 22 away from the handle assembly 10, and the plurality of side holes correspond to the plurality of through holes 23 one by one, and the corresponding side holes and through holes 23 are interconnected, wherein at least one through hole 23 is reserved for injecting drugs into the target tissue, and the electrode wires 24 and temperature sensing wires 25 inside the plurality of through holes 23 pass through the side holes and are respectively connected to the first electrode 36, the second electrode 37, the first temperature sensor 38 and the second temperature sensor 39.

[0092] In this embodiment, electrode wires 24 and temperature sensing wires 25 are respectively arranged inside the plurality of through holes 23, so that electrical connection is achieved between the first electrode 36 and the pulse device, the second electrode 37 and the pulse device, the first temperature sensor 38 and the pulse device, and the second temperature sensor 39 and the pulse device, thereby avoiding leakage of the electrode wires 24 and the temperature sensing wires 25, which is beneficial to improving the service life of the device.

[0093] In a preferred embodiment, the material of the outer catheter 21 and the inner catheter 22 is any one of the following materials: PRBAX, polytetrafluoroethylene, PA or other bendable flexible polymer materials. In this embodiment, the material of the outer catheter 21 and the inner catheter 22 is preferably polytetrafluoroethylene. Polytetrafluoroethylene is an existing mature material with good acid and alkali resistance, high temperature resistance, low friction coefficient and other characteristics. At the same time, polytetrafluoroethylene is also biocompatible and will not induce an immune response in human tissue when placed inside the human body.

[0094] Furthermore, the outer catheter 21 may also be a multi-layer structure, with a braided and spring-wound tube structure support inside and an outermost layer of a flexible polymer material. Through this arrangement, the outer catheter 21 has good support, bending and transportation properties.

[0095] The material of the first electrode 36 and the second electrode 37 is any one of the following materials: copper foil, conductive silver ink, conductive silver paste. In the present embodiment, the material of the first electrode 36 and the second electrode 37 is preferably copper foil.

[0096] In this embodiment, the above arrangement enables the first electrode 36 and the second electrode 37 to have good bendability, and when the diameter and length of the flexible circuit board 31 change, the first electrode 36 and the second electrode 37 will not break or tear.

[0097] A method for using a pulse ablation catheter, applicable to any of the above pulse ablation catheters, comprises the following steps:

[0098] Stp1: Rotate the first adjusting wheel 11 to drive the rear ends of the outer catheter 21 and the flexible circuit board 31 to rotate, thereby adjusting the diameter of the flexible circuit board 31 while keeping the length unchanged;

[0099] Stp2: reading the diameter change of the flexible circuit board 31 through the cooperation of the first pointer 14 and the first variable identifier 16;

[0100] Stp3: Rotate the second adjusting wheel 13 to drive the inner catheter 22 and the front end of the flexible circuit board 31 to rotate, and synchronously adjust the diameter and length of the flexible circuit board 31;

[0101] Stp4: Through the coordination of the second pointer 17 , the second variable identifier 18 and the third variable identifier 19 , the diameter change and the length change of the flexible circuit board 31 are read.

[0102] Embodiment 2

[0103] A pulse ablation system, comprising a power supply module, a pulse generation module, an impedance detection module, a control module, a temperature acquisition module and the pulse ablation catheter described in any one of the first embodiments, wherein a plurality of pulse electrodes are arranged inside the pulse ablation catheter, and the power supply module and the control module, the power supply module and the pulse generation module, the pulse generation module and the impedance monitoring module, and the pulse generation module and the ablation catheter are all electrically connected;

[0104] The power supply module is used to provide electrical energy;

[0105] The pulse generation module is used to send a pulse signal to the pulse ablation catheter;

[0106] The impedance detection module is used to detect the impedance value between multiple pulse electrodes of the electrode, and then determine the impedance value of the target tissue;

[0107] The control module can receive the impedance value of the target tissue detected by the impedance detection module, and determine the ablation parameters according to the impedance value of the target tissue, and the ablation parameters at least include: ablation time, pulse voltage, pulse width and pulse frequency;

[0108] The temperature acquisition module is used to collect the real-time temperature value of the target tissue;

[0109] The pulse ablation catheter is used to perform pulse ablation on the target tissue.

[0110] It should be noted that the switch from pulse ablation to radiofrequency ablation is achieved by adjusting the frequency and voltage, and pulse and radiofrequency superposition ablation is achieved according to the temperature and a predetermined time period.

[0111] In a specific embodiment, see Fig.13 As shown, a voltage is applied to the pulse electrode in the pulse ablation catheter through the power supply module, the output current is detected, the impedance value of the target tissue is determined, and the pulse ablation parameters (for example: ablation time, pulse voltage, pulse width, pulse frequency, etc.) are determined according to the impedance value of the target tissue. The target tissue is pulsed ablated, and the temperature of the target tissue and the temperature of the pulse electrode are monitored in real time through the temperature acquisition module. The resistance change of the target tissue is monitored in real time and the resistance change is analyzed through the impedance detection module. The ablation effect is judged based on the resistance change analysis results. When the resistance increases significantly and remains stable for a period of time, it can be determined that the ablation is successful. Otherwise, the ablation fails.

[0112] In another specific embodiment, see Fig.14As shown, a voltage is applied to the pulse electrode in the pulse ablation catheter through the power supply module, the output current is detected, the impedance value of the target tissue is determined, and the radio frequency parameters (for example: radio frequency power, radio frequency frequency, predetermined ablation temperature, etc.) are determined according to the impedance value of the target tissue. Radio frequency ablation is performed on the target tissue, and the temperature of the target tissue and the temperature of the pulse electrode are monitored in real time through the temperature acquisition module. The resistance change of the target tissue is monitored in real time and the resistance change is analyzed through the impedance detection module. The ablation effect is judged according to the resistance change analysis result. When the temperature of the target tissue reaches the predetermined ablation temperature, it can be determined that the ablation is successful. Otherwise, the ablation fails.

[0113] It should be noted that by adjusting the voltage of the power supply module and the frequency of the pulse generator, the pulse ablation catheter can be transformed from the pulse ablation state to the radiofrequency ablation state, so that the pulse ablation system can take into account both radiofrequency ablation and pulse ablation at the same time, and realize pulse and radiofrequency superimposed ablation according to the temperature and the predetermined time period, thereby improving the scope of application of the device and being able to meet more diverse clinical needs.

[0114] The working principle of the present invention is:

[0115] See also Fig.10 As shown, when pulse ablation is performed on the target tissue in the patient's body, the flexible circuit board 31 is delivered to the lesion through the blood vessels through the cooperation of the imaging device, and the state of the flexible circuit board 31 is adjusted according to the size of the lesion. Fig.10 As shown in a in the figure, the length of the flexible circuit board 31 is approximately equal to the length of the target tissue, and the first adjusting wheel 11 is rotated to rotate along the first expansion direction. The first adjusting wheel 11 drives the rear ends of the outer catheter 21 and the flexible circuit board 31 to rotate, so that the diameter of the flexible circuit board 31 increases (at this time, the length of the flexible circuit board 31 remains unchanged) until the flexible circuit board 31 and the target tissue are attached (as shown in a in the figure). Fig.10 As shown in b in the figure, the pulse device is started, and the ablation electric field is formed by the multiple electrodes on the flexible circuit board 31 to perform complete circumferential ablation on the target tissue; if the length of the flexible circuit board 31 is less than the length of the target tissue in the contracted state, the second adjustment wheel 13 is rotated so that the second adjustment wheel 13 rotates along the second expansion direction, and the inner catheter 22 and the flexible circuit board 31 are driven to rotate and move relative to the anti-slip handle 12 by the second adjustment wheel 13, so that the length and diameter of the flexible circuit board 31 are increased (as shown in b in the figure). Fig.10As shown at c in the figure, until the length of the flexible circuit board 31 matches the length of the target tissue. During this process, the diameter of the flexible circuit board 31 and the target tissue will present three states: first, when the flexible circuit board 31 and the target tissue are in contact, the ablation device is started to perform pulse ablation on the target tissue; second, when the flexible circuit board 31 fails to fit the target tissue, the first adjustment wheel 11 is rotated so that the first adjustment wheel 11 rotates along the first expansion direction until the flexible circuit board 31 and the target tissue are in contact (at this time, the length of the flexible circuit board 31 remains unchanged and the diameter increases); third, when the flexible circuit board 31 has already fit the target tissue and squeezes the target tissue, the first adjustment wheel 11 is rotated so that the first adjustment wheel 11 rotates along the first contraction direction Rotate until the flexible circuit board 31 and the target tissue are in contact without squeezing the target tissue (at this time, the length of the flexible circuit board 31 remains unchanged and the diameter becomes smaller). At the same time, in the process of adjusting the diameter and length of the flexible circuit board 31, through the cooperation between the first pointer 14 and the first variable mark 16, the second pointer 17 and the second variable mark 18, and the mark surface and the third variable mark 19, the diameter and length of the flexible circuit board 31 can be quickly adjusted according to the size of the target tissue, so that the flexible circuit board 31 can be completely attached to the target tissue, and the ablation electric field formed by multiple electrodes can better adapt to the target tissue, avoiding the problems of incomplete circumferential ablation and insufficient ablation area, thereby reducing the difficulty, duration and risk of pulse ablation surgery.

[0116] The above are only preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to conventional means in the art unless otherwise specified and limited.

Claims

1. A pulse ablation catheter, characterized in that: It comprises a handle assembly (10), a catheter assembly (20) and a pulse electrode assembly (30); The handle assembly (10) comprises a first adjusting wheel (11), an anti-slip handle (12) and a second adjusting wheel (13) which are arranged in sequence from one end to the other end, wherein the first adjusting wheel (11) is rotatably connected to one end of the anti-slip handle (12), and the second adjusting wheel (13) is threadedly connected to the other end of the anti-slip handle (12); The catheter assembly (20) comprises an outer catheter (21) and an inner catheter (22) which are coaxially arranged from outside to inside, the outer catheter (21) is fixed to one end of the first adjustment wheel (11), the inner catheter (22) is fixed to one end of the second adjustment wheel (13), and the inner catheter (22) is movable along the axis of the outer catheter (21); The pulse electrode assembly (30) comprises a flexible circuit board (31), the flexible circuit board (31) being mounted between the outer catheter (21) and the inner catheter (22), a plurality of ablation electrodes being arranged on the surface of the flexible circuit board (31), and in an initial state, the flexible circuit board (31) being spirally wound around the outer sides of the outer catheter (21) and the inner catheter (22), and through the cooperation of the outer catheter (21) and the inner catheter (22), the flexible circuit board (31) can be switched between a contracted state and an expanded state, and in an initial state, the flexible circuit board (31) is in a contracted state; The pulse electrode assembly (30) further comprises a first fixing element (32) and a second fixing element (33), wherein the first fixing element (32) is fixed to an end of the outer catheter (21) away from the handle assembly (10), and the second fixing element (33) is fixed to an end of the inner catheter (22) away from the handle assembly (10), and the flexible circuit board (31) and the first fixing element (32) as well as the flexible circuit board (31) and the second fixing element (33) are all fixedly connected; The diameter of the flexible circuit board (31) can be adjusted by the first adjusting wheel (11), and the length and diameter of the flexible circuit board (31) can be adjusted by the second adjusting wheel (13).

2. The pulse ablation catheter according to claim 1, characterized in that: The flexible circuit board (31) comprises a first protective layer (34), a second protective layer (35), a first electrode (36), a second electrode (37), a plurality of first temperature sensors (38) and a plurality of second temperature sensors (39); the first protective layer (34) and the second protective layer (35) are both fixed between the flexible circuit board (31) and a first fixing element (32); the first electrode (36) and the second electrode (37) are arranged on the surface of the first protective layer (34); and the plurality of first temperature sensors (38) and the plurality of second temperature sensors (39) are both assembled between the first protective layer (34) and the second protective layer (35).

3. The pulse ablation catheter according to claim 1, characterized in that: An anti-rotation groove is provided at one end of the first adjusting wheel (11) near the second adjusting wheel (13), and a first pointer (14) is slidably connected to the anti-rotation groove. A spiral groove (15) and a plurality of first variable marks (16) are provided at one end of the outside of the anti-slip handle (12) near the first adjusting wheel (11), and the plurality of first variable marks (16) are evenly distributed in a spiral shape on the outside of the anti-slip handle (12), and the first pointer (14) and the spiral groove (15) as well as the first pointer (14) and the first variable marks (16) are mutually adapted.

4. The pulse ablation catheter according to claim 1, characterized in that: One end of the second adjustment wheel (13) close to the first adjustment wheel (11) is marked as an identification surface, and a second pointer (17) is fixed to one end of the identification surface. A plurality of second variable identifications (18) and a plurality of third variable identifications (19) are provided on one end of the outer side of the anti-slip handle (12) close to the second adjustment wheel (13). The plurality of second variable identifications (18) are evenly distributed along the axial direction of the anti-slip handle (12), and the plurality of third variable identifications (19) are evenly distributed on the outer side of the anti-slip handle (12) in a spiral shape. The second pointer (17) and the second variable identification (18) as well as the identification surface and the third variable identification (19) are mutually compatible.

5. The pulse ablation catheter according to claim 1, characterized in that: The material of the outer conduit (21) and the inner conduit (22) is any one of the following materials: PRBAX, polytetrafluoroethylene, and PA.

6. The pulse ablation catheter according to claim 2, characterized in that: The material of the first electrode (36) and the second electrode (37) is any one of the following materials: copper foil, conductive silver ink, and conductive silver paste.

7. A method for using a pulse ablation catheter, applicable to a pulse ablation catheter according to any one of claims 1 to 6, characterized in that: The following steps are involved: Stp1: rotating the first adjusting wheel (11) to drive the rear ends of the outer catheter (21) and the flexible circuit board (31) to rotate, thereby adjusting the diameter of the flexible circuit board (31) while keeping the length unchanged; Stp2: reading the diameter change of the flexible circuit board (31) through the cooperation of the first pointer (14) and the first variable identifier (16); Step 3: rotating the second adjusting wheel (13) to drive the inner catheter (22) and the front end of the flexible circuit board (31) to rotate, thereby synchronously adjusting the diameter and length of the flexible circuit board (31); Stp4: Through the coordination of the second pointer (17), the second variable identifier (18) and the third variable identifier (19), the diameter change and the length change of the flexible circuit board (31) are read.

8. A pulse ablation system, characterized in that: A pulse ablation catheter comprising a power supply module, a pulse generating module, an impedance detecting module, a control module, a temperature collecting module and any one of claims 1 to 6, wherein a plurality of pulse electrodes are arranged inside the pulse ablation catheter, and the power supply module and the control module, the power supply module and the pulse generating module, the pulse generating module and the impedance monitoring module, and the pulse generating module and the ablation catheter are all electrically connected; The power supply module is used to provide electrical energy; The pulse generating module is used to send a pulse signal to the pulse ablation catheter; The impedance detection module is used to detect the impedance value between the plurality of pulse electrodes of the electrode, and then determine the impedance value of the target tissue; The control module can receive the impedance value of the target tissue detected by the impedance detection module, and determine the ablation parameters according to the impedance value of the target tissue, wherein the ablation parameters at least include: ablation time, pulse voltage, pulse width and pulse frequency; The temperature acquisition module is used to acquire the real-time temperature value of the target tissue; The pulse ablation catheter is used to perform pulse ablation on the target tissue; Wherein, by adjusting the voltage of the power supply module and the frequency of the pulse generator, the pulse ablation catheter can be transformed from the pulse ablation state to the radiofrequency ablation state.

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