Pulse ablation catheter with spiral electrode

Abstract

The invention discloses a pulse ablation catheter with a spiral electrode, and relates to the technical field of medical equipment, the pulse ablation catheter comprises an electrode main body and a catheter, the far-end structure of the electrode main body is the spiral electrode, the electrode main body can transmit torque and current, and a common electrode matched with the spiral electrode is configured around the spiral electrode; the catheter is hollow and can accommodate the electrode main body, and the catheter can guide the spiral electrode and the common electrode to a focus part in a body; wherein the outer wall of the far-end section of the electrode main body is provided with a first spiral around the electrode main body, the catheter far-end section is internally provided with a second spiral around the inner wall of the catheter far-end section, and the first spiral and the second spiral are matched for use. According to the pulse discharge ablation device, the spiral electrode can perform discharge ablation on a deep focus while human tissues are prevented from being damaged, the precession state of the spiral electrode can be more accurately controlled, and the pulse discharge ablation effect is improved.

Description

Technical Field

[0001] The invention relates to the technical field of medical equipment, and in particular to a pulse ablation catheter with a spiral electrode. Background Art

[0002] Sustained or non-sustained ventricular arrhythmias are a type of abnormal rhythm disease originating from the ventricles, including idiopathic ventricular arrhythmias and organic ventricular arrhythmias. At present, ventricular arrhythmias can be treated clinically by transcatheter pulse ablation. Pulsed Field Ablation (PFA) is a non-thermal ablation method that acts on tissue cells through an ultra-fast (<1s) electric field to destroy the stability of the cell membrane, form irreversible nanoscale micropores, cause leakage of cell contents, and ultimately cause cell death. However, some ventricular rhythms may originate from the deep myocardium, and conventional ablation techniques cannot penetrate deep myocardial lesions, resulting in the failure of ablation of this type of arrhythmia. In order to solve the above problems, a patent application with application number 202110702184.6 provides a pulsed electric field ablation catheter that can enter the tissue to solve the above problems. It uses a screw-in mechanism on the handle to control the precession of the spiral electrode. However, since the inner catheter must be made of a bendable material, it is not accurate in transmitting the torque at the handle, and its spiral electrode needle and ordinary electrode are integrated on the inner catheter, which cannot perform ordinary ablation, resulting in a narrow scope of use. In addition, when in use, the spiral electrode needle needs to be always outside the outer catheter, and the needle-like structure can easily damage the tissue in the human body, resulting in low safety. Moreover, this solution does not consider the problem of poor ablation effect caused by the stimulation and rejection reaction of the electrode material to the human tissue. Based on this, a new solution is urgently needed to at least solve some of the above defects. Summary of the invention

[0003] The purpose of the present invention is to provide a pulse ablation catheter with a spiral electrode to solve the problems existing in the above-mentioned prior art.

[0004] To achieve the above object, the present invention provides the following solutions: The present invention provides a pulse ablation catheter with a spiral electrode, comprising: The electrode body; the distal end structure of the electrode body is a spiral electrode, the free end of the spiral electrode can penetrate into human tissue, the electrode body can transmit torque and current, and the spiral electrode is surrounded by a common electrode used in conjunction with it; The catheter is hollow and can accommodate the electrode body, and a drawing wire for adjusting the bend is arranged inside the catheter. The catheter can guide the spiral electrode and the ordinary electrode to the lesion site in the body; The outer wall of the distal end section of the electrode body is provided with a first spiral wound around itself, and the distal end section of the catheter is provided with a second spiral wound around its inner wall, and the first spiral and the second spiral are respectively thread structures, and the first spiral and the second spiral are used in conjunction to enable the spiral electrode to be screwed out of the catheter and screwed into human tissue and screwed back into the catheter; The distal end section of the second spiral is flush with the distal end section of the catheter to maintain the stability of the spiral electrode's precession.

[0005] Preferably, the catheter is provided with a first liquid channel extending along its length direction, the first liquid channel is used for circulating saline or medicine, and the distal end of the catheter is provided with an outlet of the first liquid channel.

[0006] Preferably, the common electrode is disposed on the outer wall of the distal end section of the catheter, and the outlet of the first liquid channel passes through the common electrode.

[0007] Preferably, the spiral electrode is a hollow structure or a solid structure; When the spiral electrode is a hollow structure, the electrode body is provided with a second liquid channel, the second liquid channel extends into the spiral electrode and forms a hollow structure, a liquid outlet is provided on the spiral electrode, the proximal end of the second liquid channel is connected to an external infusion device, and the second liquid channel is used to circulate saline or drugs.

[0008] Preferably, a limiting ring is fixedly provided outside the electrode body, and the limiting ring is provided on the side of the first spiral facing the proximal end, and the outer diameter of the limiting ring is greater than the inner diameter of the second spiral.

[0009] Preferably, it also includes a first sensor and a second sensor, wherein the first sensor is arranged inside the catheter near the distal end, and the first sensor can be used to detect the degree of bending and / or pressure at the distal end of the catheter; the second sensor is arranged on the spiral electrode and is used to detect the temperature of the spiral electrode.

[0010] Preferably, the spiral electrode is made of nickel-titanium alloy, and the spiral electrode includes an initial state and a working state, the initial state is a spiral contracted state, and the working state is a spiral expanded state.

[0011] Preferably, an active heating device is provided on the spiral electrode. When the spiral electrode needs to be screwed out of the catheter to work, if the second sensor detects that the temperature of the spiral electrode has not reached a temperature threshold, the active heating device heats the spiral electrode so that the temperature of the spiral electrode reaches the temperature threshold, thereby converting the spiral electrode from the spiral contracted state to the spiral expanded state.

[0012] Preferably, in the spiral contracted state, the dimension of the spiral electrode along the length direction of the catheter is The dimensions of the helical electrode along the length of the catheter are the same as those of the ordinary electrode; in the spirally expanded state, the dimensions of the helical electrode along the length of the catheter are Same as target ablation depth.

[0013] Preferably, when the spiral electrode is converted from the initial state to the working state, the elastic recovery amount of the spiral electrode is and shape memory recovery The following conditions need to be met: in, is the original size of the spiral electrode before deformation; is the theoretical length dimension of the spiral electrode after deformation caused by external force, > ; And, after the spiral electrode is converted from the initial state to the working state, the corresponding shape recovery stress is: in, is the shape recovery stress, is the initial stress, is the thermoelastic modulus, T is the current temperature, is the reference temperature, is the phase transition modulus, is the change in martensite volume fraction.

[0014] Compared with the prior art, the present invention has achieved the following technical effects: 1. The first spiral and the second spiral are used in combination, so that the spiral electrode can be rotated out of the catheter and rotated into human tissue and rotated back into the catheter, thereby avoiding damage to human tissue and realizing discharge ablation of deep lesions by the spiral electrode.

[0015] 2. By arranging the first spiral and the second spiral at the distal end of the electrode body and the distal end of the catheter respectively, and the distal end section of the second spiral is flush with the distal end section of the catheter, the stability of the spiral electrode precession is maintained, and the precession state of the spiral electrode can be controlled more accurately.

[0016] 3. The spiral electrode is made of nitinol alloy, which has less irritation and rejection reaction to human tissues, is beneficial to improving the ablation effect, and the size of the spiral electrode in the spiral contraction state along the length direction of the catheter is the same as that of the ordinary electrode along the length direction of the catheter, reducing the shape difference between the spiral electrode and the ordinary electrode, which is beneficial to the synchronous control of the spiral electrode and the ordinary electrode in terms of pulse amplitude, frequency, quantity, etc. And the size of the spiral electrode in the spiral expansion state along the length direction of the catheter is the same as the target ablation depth, realizing the precise control of the ablation depth during the ablation process and further improving the ablation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 FIG. 13 is a schematic structural diagram of a pulsed ablation catheter with a spiral electrode applied in a surgical operation provided by an embodiment of the present invention; Figure 2 FIG. 18 is Figure 1 a schematic structural diagram when the structure of part A in FIG. 13 is in a normal state (without performing surgery); Figure 3 FIG. 23 is Figure 1 a schematic structural diagram when the structure of part A in FIG. 13 is in a normal state (without performing surgery) and the outer sleeve and the most distal ordinary electrode are of an integral structure; Figure 4 FIG. 28 is Figure 1 a schematic structural diagram when the structure of part A in FIG. 13 is in a normal state (without performing surgery) and a sensor is provided; In the figures: 1 - catheter; 2 - first liquid channel; 3 - spiral electrode; 4 - outer sleeve, 5 - inner sleeve, 6 - ordinary electrode; 7 - wire; 8 - pull ring; 9 - limiting ring; 10 - outlet of the first liquid channel; 11 - communication cavity; 12 - insulating layer; 13 - threaded tube or steel cable; 14 - mandrel; 15 - wire; 16 - signal receiving device; 17 - elastic structure; 18 - signal generating device; 100 - pulsed ablation catheter with a spiral electrode; 200 - bending catheter; 300 - aorta; 400 - pulmonary artery; 500 - right ventricle. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] The term "far end" in the present invention refers to the end relatively far from the external power source as a reference object, and the end relatively close to the external power source is the "far end"; the end relatively close to the external power source is the "proximal end".

[0022] like Figure 1~Figure 2 In the example shown, an embodiment of the present invention provides a pulse ablation catheter 100 with a spiral electrode, comprising: Electrode body; the distal end structure of the electrode body is a spiral electrode 3, the electrode body can transmit torque and current, and the spiral electrode 3 is surrounded by a common electrode 6 used in conjunction with it. A plurality of common electrodes 6 can be provided, and any one of the common electrodes 6 can be used as the positive and negative electrodes of the spiral electrode 3 for discharge ablation; and the two common electrodes 6 can also be used as the positive and negative electrodes of each other. When more than two common electrodes 6 are provided, any two common electrodes 6 can be used as the positive and negative electrodes of each other; The catheter 1 is hollow and can accommodate the electrode body, and the catheter 1 can guide the spiral electrode 3 and the common electrode 6 to the lesion site in the body; The outer wall of the distal end section of the electrode body is provided with a first spiral wound around itself, and the distal end section of the catheter 1 is provided with a second spiral wound around its inner wall, and the first spiral and the second spiral are used in conjunction with each other to allow the spiral electrode 3 to be screwed out of the catheter 1 and screwed into human tissue and back into the catheter 1. The first spiral and the second spiral are used in conjunction with each other to perform spiral transmission and control the spiral electrode 3 to perform screwing in and out. It can be understood that the first spiral and the second spiral include a thread structure, and the thread can also perform spiral transmission.

[0023] When in use, the bending catheter 200 is inserted through the aorta 300 to the vicinity of the left ventricle to establish an ablation catheter pathway; or the bending catheter 200 is inserted through the atrial septal puncture to establish an ablation catheter pathway. When it is necessary to ablate the protruding lesion, the distal end of the ablation catheter is extended to the vicinity of the lesion, or the distal end is placed against the tissue surface, and then the spiral electrode 3 is unscrewed from the catheter 1 to avoid damaging other healthy tissues in the body.

[0024] During the ablation of common superficial lesions, the electrode body is pushed into the left atrium or left ventricle from the internal channel of the catheter 1. The angle and position of the catheter 1 are adjusted so that the electrode on the catheter 1 fits well with the atrial wall or ventricular wall, and then discharge is performed to ablate the superficial myocardial lesions.

[0025] When ablating a deeper lesion under the ventricular wall, the effective pulse electric field range generated by the above ablation method may not cover the lesion. In this case, the catheter 1 can be adjusted so that the distal tip is roughly perpendicular to the ventricular wall and close to it, and then the electrode body is rotated so that the spiral electrode 3 is rotated out of the catheter 1 and gradually penetrates into the myocardial tissue close to the lesion tissue. Then the spiral electrode 3 and one of the common electrodes 6 (preferably the first common electrode 6 at the farthest end) are used as a pair of electrodes for discharge ablation.

[0026] The pulse ablation catheter 100 with a spiral electrode provided by the embodiment of the present invention sets the structure for controlling the precession of the spiral electrode 3 at the distal end of the electrode body, which greatly reduces the distance between the spiral electrode 3 and the control error. In other words, the embodiment of the present invention can accurately control the precession of the spiral electrode 3, that is, the displacement and rotation angle generated by the first spiral relative to the second spiral are transmitted to the spiral electrode 3, so that the spiral electrode 3 can generate the same displacement and rotation angle.

[0027] In addition, the embodiment of the present invention has two application scenarios: 1. When the spiral electrode 3 is in the catheter 1, it can be used as a common electrode 6 to perform conventional ablation surgery in the atrium or ventricle; 2. When it is necessary to ablate lesions deep in the ventricle, the spiral electrode 3 can be screwed out, increasing the usage scenarios and scope.

[0028] It should be noted that the spiral electrode 3 in the embodiment of the present invention can not only be used for ablation, but also can be used for mapping and collecting electrocardiographic signals.

[0029] In the above embodiment, the free end of the spiral electrode 3 is preferably configured as a needle to facilitate penetration into human tissue, but is not limited to the needle shape. Any structure that can penetrate human tissue can be applied to the present invention, such as a cone.

[0030] In the above embodiment, the second spiral is arranged as close as possible to the farthest end of the catheter 1 to improve the stability of the spiral electrode 3 as much as possible. Figure 1 As shown, the distal end section of the second spiral is flush with the distal end section of the catheter to maintain the stability of the spiral electrode. The first spiral is connected to one end of the spiral electrode 3, so that the error of the spiral transmission between the two can be reduced as much as possible.

[0031] In the above embodiment, the common electrode 6 is preferably configured as a ring structure, and the number is preferably two, which are arranged one in front and one behind.

[0032] As a further improvement to the above embodiment, the catheter 1 is provided with a first liquid channel 2 extending along its length direction, and the first liquid channel 2 is used to circulate drugs or saline. The distal end of the catheter 1 is provided with an outlet. When saline is circulated, the saline from the saline outlet can cool down the common electrode 6, and the saline from the saline outlet can also be used as a conductive medium for conducting electricity. When drugs are circulated, the tissue can be treated with drugs, and when the drugs are developer, they can be used for development to indicate the position of the head end.

[0033] This embodiment can ensure the safety of the operation, prevent the electrode from generating excessive heat and burning human tissue, and can also use saline as an electrolyte to conduct electricity, thereby further expanding the applicability of the device and improving ablation efficiency and effect.

[0034] Specifically, the first liquid channel 2 is formed between the conduit 1 and the electrode body, and the electrode body is coated or wrapped with an insulating layer 12 .

[0035] In order to further improve the cooling effect, the embodiment of the present invention configures the common electrode 6 on the outer wall of the distal section of the catheter 1, and the saline outlet runs through the common electrode 6, so that the saline overflows from the surface outlet of the common electrode 6 to the surface of the common electrode 6, thereby improving the cooling effect.

[0036] Correspondingly, considering that the spiral electrode 3 may also need to be cooled, in some embodiments, the electrode body is hollow and a second liquid channel is formed therein, a liquid outlet is opened on the spiral electrode 3, the proximal end of the second liquid channel is connected to an external infusion device, and the second liquid channel is used to circulate saline or drugs. The electrode body can be a hollow steel cable, and the proximal end of the steel cable 13 is connected to the external equipment and transmits current; in some embodiments, the electrode body can also include a hollow core shaft 14, the core shaft 14 is embedded in the steel cable, the core shaft 14 and the steel cable are used together for conduction, the second liquid channel is arranged in the core shaft 14, and the distal end of the core shaft 14 and the spiral electrode 3 are an integrated structure or welded connection.

[0037] This embodiment can cool the spiral electrode 3, and can also inject saline into human tissue to serve as an electrolyte for electrical conduction, and can also use the second liquid channel to inject drugs into human tissue.

[0038] As a further improvement to this embodiment, the liquid outlet is arranged near the needle-shaped tip of the spiral electrode 3, so that the saline flow can be better cooled when passing through the spiral electrode 3. If necessary, the liquid outlet can also be arranged at the tip.

[0039] It should be noted that in the above-mentioned embodiments with cooling effect, whether it is the improvement of the electrode body or the improvement of the catheter 1, it only belongs to the preferred embodiments of the present invention. It can be understood that the first liquid channel 2 and the second liquid channel may not be provided in the embodiments of the present invention, which makes the spiral electrode 3 a solid structure.

[0040] In order to prevent the excessive rotation of the spiral electrode and damage to human tissue, in some embodiments, a limit ring 9 is fixedly provided on the outside of the electrode body. The limit ring 9 is arranged on the side of the first spiral toward the proximal end. The outer diameter of the limit ring 9 is larger than the inner diameter of the second spiral. During the rotation process, when the limit ring 9 abuts against one end of the second spiral, the electrode body can stop rotating, thereby avoiding excessive rotation.

[0041] In addition, the degree to which the spiral electrode 3 can be screwed in is related to the distance between the limiting ring 9 and the first spiral. Therefore, different surgeries can use electrode bodies with different distances. For example, when the lesion is located inside the tissue but not deep, an electrode body with a smaller distance between the limiting ring 9 and the first spiral is selected. On the contrary, an electrode body with a larger distance between the limiting ring 9 and the first spiral is selected. This requires the preparation of a variety of electrode bodies with different distances. In order to more accurately control the above-mentioned distance, the limiting ring 9 can be set as an adjustable structure. For example, the limiting ring 9 can be threadedly connected to the electrode body, and a thread, preferably a fine thread, needs to be set on the corresponding part of the electrode body. This can accurately control the distance between the limiting ring 9 and the first spiral, and then control the screw-in depth of the spiral electrode 3 to ensure the safe implementation of the operation as much as possible.

[0042] In some embodiments, a drawing wire 7 and a pull ring 8 for adjusting the bending are disposed in the catheter 1. Controlling the bending of the catheter 1 by the drawing wire 7 is a solution in the prior art, and its effects and implementation methods are not described in detail here.

[0043] In some embodiments, the first spiral and the second spiral are formed on two screw sleeves respectively, and the screw sleeves can be made of metal material or non-metallic insulating material. When the screw sleeve is made of metal material, the first liquid channel 2 is connected to the space where the screw sleeve is located, and the spiral electrode 3 is connected to the common electrode 6 on the outside of the spiral electrode 3 through the screw sleeve to form an electrode for discharge or marking; when the screw sleeve is made of non-metallic insulating material, the spiral electrode 3 is used alone as an electrode for marking or discharge.

[0044] like Figure 2 and 3 As shown, the outer wall of the outer screw sleeve 4 is provided with an annular communication cavity 11 , and the communication cavity 11 is connected with the first liquid channel 2 and the outlet on the common electrode 6 .

[0045] In addition, the common electrode 6 at the farthest end and the outer screw sleeve 4 can be integrally arranged to form a conductive path, such as Figure 3 shown.

[0046] In some embodiments, the present invention also includes a first sensor and a second sensor, wherein the first sensor is arranged inside the catheter near the distal end, and the first sensor can be used to detect the degree of bending and / or pressure at the distal end of the catheter 1; the second sensor is arranged on the spiral electrode and is used to detect the temperature of the spiral electrode.

[0047] The first sensor in this embodiment may be a displacement sensor, an optical fiber sensor, a pressure sensor, etc.

[0048] Taking the displacement sensor as an example, a signal generating device 18 , an elastic structure 17 , a signal receiving device 16 and a wire 15 are provided in the catheter 1 .

[0049] Among them, the signal generating device 18: the deformation or force borne by the catheter 1 is transmitted to the signal generating device 18, so that it sends out a signal.

[0050] Signal receiving device 16: The signal sent by the signal generating device 18 is captured by the signal receiving device 16 and converted into an electrical signal. Three or more signal receivers can be set in the catheter 1 to identify the angle and displacement of the catheter 1. In some embodiments, the pressure on the catheter 1 can also be detected.

[0051] The elastic structure 17 is used to absorb the deformation of the catheter 1 and measure the pressure value at the tip of the catheter 1 .

[0052] Wire 15: transmits the electrical signal formed by the signal receiving device 16 to the terminal.

[0053] like Figure 4 As shown, specifically, the signal generating device 18 and the signal receiving device 16 in the above-mentioned embodiment are both spiral conductive structures, which can generate electromagnetism and magnetoelectricity phenomena, so as to complete the conversion of signals, wherein the outer screw sleeve 4, the signal generating device 18, the elastic structure 17 and the signal receiving device 16 are connected in sequence, and the signal generating device 18 is connected with electric current, when the distal end of the catheter 1 is bent, the signal generating device 18 is bent therewith, and a variable magnetic field signal is generated, and the signal receiving device 16 generates a variable electric current after receiving the variable magnetic field signal and transmits it outwardly through the wire 15, so as to realize that the bending degree is presented by the change of electric current. The spring constant of the elastic structure 17 is a predetermined value, and the deformation of the elastic structure 17 can be obtained by the relative position change of the signal generating device 18 and the signal receiving device 16, and the pressure value of the catheter 1 head end causing the deformation of the catheter 1 can be calculated according to Hooke's law.

[0054] Therefore, the embodiment of the present invention can detect the angle change and displacement (i.e., the degree of bending) of the distal end of the catheter 1, and then accurately control the bending of the catheter 1 through wire drawing. The embodiment of the present invention can detect the contact force between the distal end of the catheter 1 and the tissue, and then achieve safer in vivo catheter manipulation.

[0055] In this embodiment, the second sensor may be a temperature sensor, which is used to detect and obtain the temperature of the spiral electrode 3 .

[0056] As a further improvement to the above embodiment, the spiral electrode is made of nickel-titanium alloy. The nickel-titanium alloy has a shape memory effect and excellent biocompatibility, which means that it has less stimulation and rejection reaction to human tissue. Based on the above advantages, the use of nickel-titanium alloy to make the spiral electrode 3 can adapt to more abundant ablation scenarios and improve the ablation effect.

[0057] When the spiral electrode 3 is made of nickel-titanium alloy, the spiral electrode 3 includes an initial state and a working state, wherein the initial state is a spiral contracted state, and the working state is a spiral expanded state.

[0058] In order to make full use of the shape memory effect of nickel-titanium alloy, an active heating device (not shown in the figure) is provided on the spiral electrode 3. When the spiral electrode 3 needs to be screwed out of the catheter for work, if the second sensor detects that the temperature of the spiral electrode 3 does not reach the temperature threshold, the active heating device is controlled to heat so that the temperature of the spiral electrode 3 reaches the temperature threshold, thereby converting the spiral electrode 3 from the spiral contraction state to the spiral expansion state.

[0059] The second sensor and the active heating device communicate with external devices through signal lines respectively arranged in the steel cable 13. The second sensor transmits only uplink signals, i.e., the detected temperature value, through the corresponding signal lines, and the active heating device receives only downlink signals, i.e., the control signals for switching the active heating device, through the corresponding signal lines. The outside of the signal lines are wrapped with an insulating layer to shield electromagnetic interference.

[0060] In the pulse ablation scenario, it is necessary to consider the possible damage to human tissue caused by temperature changes during the ablation process, as well as the impact on the ablation effect. Therefore, when the spiral electrode is made of nickel-titanium alloy, the temperature threshold for the spiral electrode 3 to switch from the spiral contraction state to the spiral expansion state is set close to the temperature of human tissue, thereby avoiding the impact of temperature differences on the ablation operation.

[0061] Furthermore, the spiral electrode 3 made of nickel-titanium alloy has a dimension along the length direction of the catheter in the spiral contracted state. The dimensions of the helical electrode 3 and the common electrode 6 along the length direction of the catheter are the same. In this case, the shape difference between the helical electrode 3 and the common electrode 6 is reduced, and when the helical electrode 3 and the common electrode 6 cooperate with each other as a pair of electrodes for discharge ablation, it is easier to achieve synchronous control of pulse amplitude, frequency, quantity, etc.

[0062] In the spirally expanded state, the dimension of the spiral electrode 3 along the length direction of the catheter is The target ablation depth is the same as the target ablation depth, so that the spiral electrode 3 can be more easily rotated to the target depth to fully perform discharge ablation.

[0063] Furthermore, the spiral electrode 3 made of nickel-titanium alloy has an elastic recovery amount of and shape memory recovery The following conditions need to be met: in, is the original size of the spiral electrode before deformation; is the theoretical length dimension of the spiral electrode after deformation caused by external force, > .

[0064] Furthermore, after the spiral electrode 3 is converted from the initial state to the working state, the corresponding shape recovery stress is: in, is the shape recovery stress, is the initial stress, is the thermoelastic modulus, T is the current temperature, is the reference temperature, is the phase transition modulus, is the change in martensite volume fraction.

[0065] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A pulse ablation catheter with a spiral electrode, characterized in that: include: Electrode body; The distal end structure of the electrode body is a spiral electrode, the free end of the spiral electrode can penetrate human tissue, the electrode body can transmit torque and current, and the spiral electrode is surrounded by a common electrode used in conjunction with it; The catheter is hollow and can accommodate the electrode body, and a drawing wire for adjusting the bend is arranged inside the catheter. The catheter can guide the spiral electrode and the ordinary electrode to the lesion site in the body; The outer wall of the distal end section of the electrode body is provided with a first spiral wound around itself, and the distal end section of the catheter is provided with a second spiral wound around its inner wall, and the first spiral and the second spiral are respectively thread structures, and the first spiral and the second spiral are used in conjunction to enable the spiral electrode to be screwed out of the catheter and screwed into human tissue and screwed back into the catheter; The distal end section of the second spiral is flush with the distal end section of the catheter to maintain the stability of the spiral electrode's precession.

2. The pulse ablation catheter with a spiral electrode according to claim 1, characterized in that: The catheter is provided with a first liquid channel extending along the length direction thereof, the first liquid channel is used for circulating saline or medicine, and the distal end of the catheter is provided with an outlet of the first liquid channel.

3. The pulse ablation catheter with a spiral electrode according to claim 2, characterized in that: The common electrode is disposed on the outer wall of the distal end section of the catheter, and the outlet of the first liquid channel passes through the common electrode.

4. The pulse ablation catheter with a spiral electrode according to claim 1, characterized in that: The spiral electrode is a hollow structure or a solid structure; When the spiral electrode is a hollow structure, the electrode body is provided with a second liquid channel, the second liquid channel extends into the spiral electrode and forms a hollow structure, a liquid outlet is provided on the spiral electrode, the proximal end of the second liquid channel is connected to an external infusion device, and the second liquid channel is used to circulate saline or drugs.

5. The pulse ablation catheter with a spiral electrode according to claim 1, characterized in that: A limiting ring is also fixedly arranged outside the electrode body, and the limiting ring is arranged on the side of the first spiral facing the proximal end, and the outer diameter of the limiting ring is greater than the inner diameter of the second spiral.

6. The pulse ablation catheter with a spiral electrode according to claim 1, characterized in that: It also includes a first sensor and a second sensor. The first sensor is arranged inside the catheter near the distal end, and the first sensor can be used to detect the bending degree and / or pressure of the distal end of the catheter; the second sensor is arranged on the spiral electrode and is used to detect the temperature of the spiral electrode.

7. The pulse ablation catheter with a spiral electrode according to claim 6, characterized in that: The spiral electrode is made of nickel-titanium alloy and includes an initial state and a working state. The initial state is a spiral contracted state, and the working state is a spiral expanded state.

8. The pulse ablation catheter with a spiral electrode according to claim 7, characterized in that: An active heating device is provided on the spiral electrode. When the spiral electrode needs to be unscrewed from the catheter to work, if the second sensor detects that the temperature of the spiral electrode has not reached a temperature threshold, the active heating device heats the spiral electrode so that the temperature of the spiral electrode reaches the temperature threshold, thereby converting the spiral electrode from the spiral contracted state to the spiral expanded state.

9. The pulse ablation catheter with a spiral electrode according to claim 8, characterized in that: In the spiral contracted state, the dimension L2 of the spiral electrode along the length of the catheter is the same as the dimension of the ordinary electrode along the length of the catheter; in the spiral expanded state, the dimension L3 of the spiral electrode along the length of the catheter is the same as the target ablation depth.

10. The pulse ablation catheter with a spiral electrode according to claim 9, characterized in that: When the spiral electrode is converted from the initial state to the working state, the elastic recovery amount ε of the spiral electrode is el and shape memory recovery ε sme The following conditions need to be met: ε el (L2-L1) / L0 <h2 style=";text-align:left;direction:ltr">ε<h2 style=";text-align:left;direction:ltr"> sme <h2 style=";text-align:left;direction:ltr"> (L3-L2) / L0 Wherein, L0 is the original size of the spiral electrode before deformation; L1 is the theoretical length size after the spiral electrode is deformed by applying external force, L0>L1; and after the spiral electrode is converted from the initial state to the working state, the corresponding shape recovery stress is: Among them, σ rec is the shape recovery stress, σ0 is the initial stress, is the thermoelastic modulus, T is the current temperature, T0 is the reference temperature, Ω is the phase transformation modulus, and △ξ is the change in martensite volume fraction.

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