Radio frequency ablation catheter and radio frequency ablation system

Abstract

The invention discloses a radiofrequency ablation catheter and a radiofrequency ablation system.The radiofrequency ablation catheter comprises a center rod, a plurality of supporting rods and an electrode set, the multiple supporting rods are arranged around the center rod and form a cage-shaped structure, and the supporting rods are made of polyether block amide; the electrode group comprises a plurality of electrodes, the plurality of electrodes at least comprise a positive electrode and a negative electrode, each supporting rod is connected with one electrode group, and each electrode in the electrode group is at least partially exposed. The ablation effect of the radiofrequency ablation catheter can be improved through the design of the supporting rod material and the electrode set.

Description

Technical Field

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

[0002] Hypertension is a global health problem that affects approximately 11-16% of hypertensive patients. Despite the availability of a variety of drug treatment options, a considerable number of patients are unable to control their blood pressure with medication, leading to an increase in cardiovascular disease. The difficulty in treating refractory hypertension lies in the poor efficacy of existing drug treatments, large side effects, and poor patient compliance. In addition, existing radiofrequency ablation catheter devices pose a risk of skin burns and renal blood flow obstruction.

[0003] There is an urgent need to improve the radiofrequency ablation catheter to ensure the ablation effect of the radiofrequency ablation catheter. Summary of the invention

[0004] The present application mainly provides a radiofrequency ablation catheter and a radiofrequency ablation system, which can have a good ablation effect when used.

[0005] In order to solve the above technical problems, the technical solution adopted in the present application is: to provide a radiofrequency ablation catheter, which includes a central rod, a plurality of struts and an electrode group, wherein the plurality of struts are arranged around the central rod and the plurality of struts form a cage-like structure, and the material of the struts includes polyether block amide; the electrode group includes a plurality of electrodes, and the plurality of electrodes include at least one positive electrode and one negative electrode, wherein each of the struts is connected to one of the electrode groups, and each of the electrodes in the electrode group is at least partially exposed.

[0006] Wherein, the number of the support rods is three.

[0007] The support rod is provided with an opening, and the electrodes in the electrode group are partially embedded in the support rod and partially exposed from the opening.

[0008] Wherein, in the axial direction of the central rod, the electrode groups connected by the plurality of support rods are arranged at intervals.

[0009] Wherein, the outer surface of the support rod is coated with insulating material.

[0010] Wherein, the radiofrequency ablation catheter further comprises an insulating layer, which is arranged on the outer circumference of the strut and separates the electrodes in the electrode group.

[0011] Wherein, the radiofrequency ablation catheter further includes a temperature sensor, which is arranged on the outer circumference of the strut; and / or, the radiofrequency ablation catheter further includes a pressure sensor, which is arranged on the outer circumference of the strut.

[0012] Another technical solution adopted in the present application is to provide a radiofrequency ablation system, which includes: the radiofrequency ablation catheter and the wire group described in the above embodiment; wherein the wire group includes a plurality of wires, each of the struts is provided with the wire group, one end of the wire is electrically connected to the electrode, and the other end of the wire is connected to the radiofrequency generator.

[0013] The radiofrequency ablation system further comprises a guide wire, which is arranged in the support rod and is used to support the support rod to ensure that the support rod is in contact with the area to be ablated.

[0014] Among them, the center rod is also provided with a flushing channel connected to an external syringe, and the side wall of the center rod is provided with a through hole adjacent to the flushing channel. The flushing liquid flows out through the through hole located on the side wall of the center rod and is used for flushing during ablation; the radio frequency ablation system also includes a linear amplifier, which is electrically connected to the radio frequency generator and the electrode group, and is used to amplify the radio frequency signal of the electrode to ensure that a sufficient voltage difference is generated between the electrodes to complete the ablation operation.

[0015] The beneficial effects of the present application are as follows: in the radiofrequency ablation catheter of the present application, through the design of the electrode group and the strut, and the use of polyether block amide material for the strut, radiofrequency ablation of the kidney can be performed through bipolar electrodes without using an external grounding pad, thereby reducing the risk of skin burns and maintaining renal blood flow, and improving the ablation effect of the radiofrequency ablation catheter. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0017] Figure 1 This is a schematic structural diagram of an implementation method of a radiofrequency ablation catheter in this application;

[0018] Figure 2 for Figure 1 A structural schematic diagram of an embodiment of the radiofrequency ablation catheter in a working state;

[0019] Explanation of reference numerals: 100 radiofrequency ablation catheter; 10 center rod; 20 support rod; 21 opening; 30 electrode group; 31 electrode; 40 insulating layer. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0022] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0023] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0024] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0025] See also Figure 1 and Figure 2The present application provides a radiofrequency ablation catheter 100, which includes a central rod 10, a plurality of struts 20 and an electrode group 30, wherein the plurality of struts 20 are arranged around the central rod 10 and the plurality of struts 20 form a cage-like structure, and the material of the struts 20 includes polyether block amide; the electrode group 30 includes a plurality of electrodes 31, and the plurality of electrodes 31 include at least one positive electrode and one negative electrode, wherein each strut 20 is connected to an electrode group 30, and each electrode 31 in the electrode group 30 is at least partially exposed.

[0026] Specifically, the central rod 10 is designed to guide the strut 20, especially when the radiofrequency ablation catheter 100 enters the femoral artery through the guide sheath. The strut 20 adopts a cage-like structure design, and the material includes a thermoplastic material (such as polyether block amide), which provides the flexibility and shape memory properties of the strut 20 structure, facilitating the use of the strut 20 in the ablation area. Each strut 20 is connected to an electrode group 30, and each electrode 31 in the electrode group 30 is at least partially exposed. The multiple electrodes 31 in the electrode group 30 are arranged along the axial direction of the strut 20, and the exposed electrodes 31 are used to approach or contact the ablation area for ablation. The electrode group 30 includes two to four electrodes 31. In one embodiment, the electrode group 30 includes two electrodes 31, which are respectively a positive electrode and a negative electrode. In another embodiment, the electrode group 30 includes three electrodes 31, which are respectively a negative electrode, a positive electrode and a negative electrode, arranged in sequence. In another embodiment, the electrode group 30 includes four electrodes 31, which are respectively a negative electrode, a positive electrode, a negative electrode and a positive electrode, arranged in sequence. The electrode 31 is the core part of the radiofrequency ablation catheter 100, and is used to transmit radiofrequency energy to achieve tissue ablation. The electrode 31 is designed to be cylindrical, with a specific diameter and length, and is exposed in a specific area to contact the renal artery wall and transmit current. This design allows energy to be concentrated on the target tissue, reducing the impact on the surrounding blood flow, and ensuring precise control of the ablation area.

[0027] Please continue reading Figure 1 and Figure 2 , in an unrestricted open space, such as Figure 1 As shown, the radiofrequency ablation catheter 100 can be unfolded and present a preformed shape, which is adapted to the internal structure of the renal artery, and the entire structure includes a polyether block amide material with good elasticity. Figure 2 As shown, the catheter is deployed in a confined space such as an artery. The design of the radiofrequency ablation catheter 100 in the present application takes into account both good fit with the inner wall of the blood vessel and avoiding unnecessary damage or stenosis to the blood vessel.

[0028] Please continue reading Figure 1 and Figure 2, the number of the struts 20 is three. The design of three struts 20 enables the radiofrequency ablation catheter 100 to ablate target tissues in different regions, which is more flexible to use. Of course, in other embodiments, the number of the struts 20 can also be more, such as four, five or six.

[0029] Please continue reading Figure 1 and Figure 2 The support rod 20 is provided with an opening 21, and the electrode 31 in the electrode group 30 is partially embedded in the support rod 20 and partially exposed from the opening 21. Specifically, the design of the opening 21 in the support rod 20 facilitates the electrode 31 to be exposed from the side wall of the support rod 20, thereby facilitating the contact between the electrode 31 and the area to be ablated.

[0030] Please continue reading Figure 1 and Figure 2 In the axial direction of the central rod 10, the electrode groups 30 connected to the plurality of struts 20 are arranged at intervals. Specifically, the electrode groups 30 arranged at intervals avoid the electrode groups 30 being able to ablate only in one plane of the region to be ablated, and can achieve ablation in multiple regions to be ablated that are not on the same horizontal plane.

[0031] The outer surface of the support rod 20 is coated with an insulating material. Since the electrode 31 needs to be energized to operate, after the outer surface of the support rod 20 is coated with an insulating material, the current can be prevented from directly flowing through the side wall of the support rod 20, thereby ensuring the use effect.

[0032] Please continue reading Figure 1 and Figure 2 The radiofrequency ablation catheter 100 further includes an insulating layer 40, which is disposed on the outer circumference of the strut 20 and separates the electrodes 31 in the electrode group 30. Specifically, the electrodes 31 are convexly disposed on the strut 20. In order to ensure the normal operation of the electrodes 31, the insulating layer 40 is designed to insulate adjacent electrodes 31.

[0033] In one embodiment, the radiofrequency ablation catheter 100 further includes a temperature sensor, which is disposed on the outer circumference of the strut 20. Specifically, the temperature sensor is connected to the electrode 31 plug through a guide wire to ensure the operation needs of the temperature sensor. The temperature sensor is a sheet structure with a small volume, which is convenient for use on the radiofrequency ablation catheter 100. At the same time, the temperature sensor can be disposed on one side of the electrode group 30, and the temperature sensor includes but is not limited to a thermocouple, and can also be a thermal resistance thermometer.

[0034] In one embodiment, the RF ablation catheter 100 further includes a pressure sensor, which is disposed on the outer circumference of the strut 20. Specifically, the pressure sensor is connected to the electrode 31 plug via a guide wire to ensure the operation needs of the pressure sensor. The pressure sensor is a sheet-like structure with a small volume, which is convenient for use on the RF ablation catheter 100. At the same time, the pressure sensor can be disposed on the other side of the electrode group 30 to achieve a compact structural design of the RF ablation catheter 100.

[0035] Another technical solution adopted in the present application is to provide a radiofrequency ablation system, which includes: the radiofrequency ablation catheter 100 and the wire group described in the above embodiment; wherein the wire group includes a plurality of wires, each strut 20 is provided with a wire group, one end of the wire is electrically connected to the electrode 31, and the other end of the wire is connected to the radiofrequency generator. Specifically, the radiofrequency generator is used to provide a radiofrequency signal to the electrode 31 to generate sufficient heat to achieve tissue ablation. In addition, a standard electrical connector is provided at the proximal end of the radiofrequency ablation catheter 100 for connecting to an external radiofrequency generator or monitoring equipment to facilitate the use of the radiofrequency ablation system.

[0036] In one embodiment, the radiofrequency ablation system further comprises a guide wire, which is disposed in the strut 20 and is used to support the strut 20 and ensure that the strut 20 is in contact with the area to be ablated. Specifically, the guide wire material comprises nickel-titanium alloy, and the guide wire is used to provide the shape and support of the cage-like structure of the strut 20, so that the strut 20 can maintain a desired shape in the renal artery and maintain contact with the inner wall of the artery.

[0037] In one embodiment, a flushing channel connected to an external syringe is further provided inside the central rod 10, and a through hole adjacent to the flushing channel is provided on the side wall of the central rod 10, and the flushing liquid flows out through the through hole located on the side wall of the central rod for flushing during ablation. The flushing liquid can be physiological saline to improve the contact between the electrode 31 and the blood vessel wall.

[0038] In one embodiment, the radiofrequency ablation system further includes a linear amplifier electrically connected to the radiofrequency generator and the electrode group 30 for amplifying the radiofrequency signal of the electrode 31 to ensure that a sufficient voltage difference is generated between the electrodes 31 to complete the ablation procedure.

[0039] Together, these components form a complete bipolar radiofrequency ablation system used to precisely ablate the nerve tissue surrounding the kidney to treat hypertension without interrupting blood flow in the renal arteries.

[0040] This application is a technical solution for creating a computational model and using this model to design a bipolar radiofrequency ablation catheter 100 for renal denervation, optimizing the design, size and geometry of the electrode 31 through numerical simulation to predict the precise location and size of the ablation area. The specific implementation process is as follows:

[0041] 1. Design of bipolar radiofrequency ablation catheter 100 and computational model.

[0042] First, a bipolar radiofrequency ablation catheter 100 for radiofrequency ablation is designed. The design of the catheter should take into account the specific specifications and physical properties of the catheter to ensure that it can perform effective radiofrequency ablation operations. In addition, a computational model needs to be created to simulate the operation of the catheter and predict the results of ablation. The design process can be carried out using engineering software and computer-aided design tools.

[0043] 2. Create a model using numerical simulation software.

[0044] After the design is completed, the next step is to create a computational model. The electrical and thermal properties of the arterial wall, surrounding connective tissue, and electrode 31 must be considered in this model. The model can be created using finite element analysis using numerical simulation software. This process requires the establishment and solution of electric and thermal field equations, and the temperature distribution and current density of the catheter during operation can be obtained. This model creation process is very professional and complex, requiring appropriate physical knowledge and computer simulation technology.

[0045] Based on the catheter operating parameters and model results, the size and shape of the ablation area can be predicted. The predicted result is 2.1mm (width) x 9.0mm (length) x 1.7mm (height), and it is proved that radiofrequency ablation can be achieved without a return ground pad. This prediction method can be adjusted according to actual needs and can provide an intuitive display of the ablation effect.

[0046] According to the calculation model created by the numerical simulation software, the radiofrequency ablation process is simulated by setting the electrical and thermal property parameters of the electrode 31 and the biological tissue (arterial wall and surrounding connective tissue). During the simulation process, a complex physical problem involving factors such as the electrical conductivity of biological tissue, the input of radiofrequency power, and the thermal conduction of biological tissue is processed.

[0047] First, the RF power input parameters of electrode 31 need to be set, including: RF frequency 200kHz to 500kHz, peak-to-peak voltage: 60Vp-p, peak current 4.76mA, peak power 0.1W, ablation time 60s. Secondly, taking into account the electrical conductivity and thermal conductivity characteristics of biological tissues, the model will calculate the distribution of RF power in biological tissues, how the current flows in the tissues, that is, the distribution of current density. Current density (J) is the ratio of current (I) to the area (A) passed through, and the unit is usually amperes per square meter (A / m 2 ). The model shows the spatial distribution of the current density, usually expressed in the form of a vector field.

[0048] Since radiofrequency ablation uses radiofrequency electrical energy to convert into heat energy in biological tissues, thereby causing the tissues to reach a certain temperature, thereby achieving the purpose of ablation or coagulation. Therefore, the model will further calculate the temperature distribution of biological tissues under the action of radiofrequency electrical energy based on the distribution of current density. The temperature distribution can directly determine the size and shape of the ablation area. Specifically, an area where the temperature reaches a certain threshold (such as 50°C) can be considered an ablation area.

[0049] Through the above process, the size and shape of the ablation area can be predicted. In this process, multiple iterations of optimization may be required to obtain the desired ablation effect by adjusting the radio frequency power input parameters or the design parameters of the electrode 31.

[0050] The radiofrequency ablation catheter and radiofrequency ablation system in this application have the following advantages:

[0051] 1. No external grounding pad is required: The conventional monopolar RF ablation catheter 100 requires the use of a grounding pad outside the patient's body, which poses a risk of causing skin burns. The design of the bipolar RF ablation catheter 100 eliminates this risk because the current flows between the two electrodes 31 and does not need to return through the patient's body.

[0052] 2. No blockage of renal artery blood flow: Some existing devices, such as catheters using inflatable balloons, may block renal artery blood flow during ablation. The design of the bipolar radiofrequency ablation catheter 100 allows blood flow to continue during ablation because it does not require the use of balloons to fix the electrode 31.

[0053] 3. Low power requirement: The new catheter is designed to use lower RF power (≤1.0W), which helps reduce thermal damage to surrounding tissues while reducing the complexity and cost of the catheter.

[0054] 4. Precise control of the ablation area: Through the design and optimization of bipolar or multipolar electrodes, the shape and size of the ablation area can be more accurately controlled, thereby more accurately targeting and ablating the nerve tissue around the renal artery.

[0055] 5. Fast and easy iterative optimization: Using numerical simulation and finite element models, design iteration and optimization can be quickly performed on the computer, reducing the trial and error process of physical prototypes and accelerating the product development cycle.

[0056] 6. Potential biosignal mapping function: The design of bipolar electrodes or multipolar electrodes provides possible biosignal mapping function in the future, which helps to determine the optimal ablation location and improve the accuracy and effectiveness of treatment.

[0057] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A radiofrequency ablation catheter, characterized in that: include: Center rod; A plurality of struts are arranged around the central rod and the plurality of struts form a cage-like structure, wherein the material of the struts comprises polyether block amide; The electrode group includes a plurality of electrodes, wherein the plurality of electrodes include at least one positive electrode and one negative electrode, wherein each of the support rods is connected to one of the electrode groups, and each of the electrodes in the electrode group is at least partially exposed.

2. The radiofrequency ablation catheter according to claim 1, characterized in that: The number of the support rods is three.

3. The radiofrequency ablation catheter according to claim 1, characterized in that: The support rod is provided with an opening, and the electrodes in the electrode group are partially embedded in the support rod and partially exposed from the opening.

4. The radiofrequency ablation catheter according to claim 1, characterized in that: In the axial direction of the central rod, the electrode groups connected by the plurality of support rods are arranged at intervals.

5. The radiofrequency ablation catheter according to claim 1, characterized in that: The outer surface of the support rod is coated with insulating material.

6. The radiofrequency ablation catheter according to claim 1, characterized in that: Also includes: The insulating layer is disposed on the outer circumference of the support rod and separates the electrodes in the electrode group.

7. The radiofrequency ablation catheter according to claim 1, characterized in that: Also includes: A temperature sensor is arranged on the outer peripheral surface of the support rod; And / or, a pressure sensor is arranged on the outer peripheral surface of the support rod.

8. A radiofrequency ablation system, characterized in that: include: The radiofrequency ablation catheter according to any one of claims 1 to 7; The wire group includes a plurality of wires. The wire group is arranged in each of the struts. One end of the wire is electrically connected to the electrode, and the other end of the wire is connected to a radio frequency generator.

9. The radiofrequency ablation system according to claim 8, characterized in that: Also includes: The guide wire is arranged in the support rod and is used to support the support rod to ensure that the support rod is in contact with the area to be ablated.

10. The radiofrequency ablation system according to claim 8, characterized in that: The central rod is also provided with a flushing channel connected to an external syringe, and the side wall of the central rod is provided with a through hole adjacent to the flushing channel, and the flushing liquid flows out through the through hole located on the side wall of the central rod for flushing during ablation; A linear amplifier is electrically connected to the radio frequency generator and the electrode group, and is used to amplify the radio frequency signal of the electrode.

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