An ablation catheter

Abstract

The present disclosure provides an ablation catheter. The ablation catheter comprises: an elongated strip body comprising a distal segment capable of extending into a blood vessel lumen; an ablation electrode arranged along the axial of the distal segment of the elongated strip body and surrounding the distal segment, wherein the ablation electrode is configured to have two ends of elastic structure and a middle segment connecting the two ends of the ablation electrode through a spiral structure; and a perfusion liquid outflow hole arranged on the surface of the elongated strip body. Compared with ultrasonic ablation equipment, the ablation catheter of the present disclosure has the advantages of mature technology, lower cost and higher energy conversion efficiency, and can uniformly emit radio frequency energy in the circumferential direction, does not require strong directivity, the electrode is more firm compared with glue connection, the ablation strength and depth are uniform, and has good radial adaptability in the target blood vessel.

Description

Technical Field

[0001] This disclosure relates to the field of medical device technology, specifically to an ablation catheter. Background Technology

[0002] In existing technologies, ablation products for the major visceral nerve (GSN) mainly utilize radiofrequency ablation and ultrasound ablation. The high cost of components such as the ultrasound transducer in ultrasound ablation catheters hinders mass production. Radiofrequency ablation lacks a specific and sensitive target; it releases RF electromagnetic energy through the vascular endothelium, which, upon contact with the tissue, is converted into heat. This heat is conducted through the blood vessel to the nerve fibers outside the vessel, causing dehydration and coagulative necrosis, thus blocking nerve signal transmission. Compared to ultrasound ablation, radiofrequency ablation technology is mature and less expensive, and is gradually becoming the mainstream approach. However, existing radiofrequency ablation devices suffer from poor radial elasticity in blood vessels due to axial stiffness issues after intervention. In some existing ablation catheters, the transmission lines are intertwined, leading to interference between acoustic and thermal ablation signals, and the transmission lines become entangled, which is also detrimental to the placement of leads within the catheter. In other existing ablation catheters, the electrodes are connected with glue, which also presents a risk of detachment due to the lack of secure connection. In still other existing ablation catheters, the electrodes have inconsistent spacing or contact surfaces, resulting in uneven current density along the axial direction, leading to uneven ablation intensity and depth.

[0003] Therefore, existing technologies still need to be improved and enhanced. Summary of the Invention

[0004] To address at least one of the aforementioned problems, as well as one or more other potential problems, this disclosure proposes an ablation catheter that can emit radiofrequency energy uniformly in a circumferential direction without strong directionality, has a more robust electrode connection than glue, provides uniform ablation intensity and depth, and exhibits excellent radial adaptability to the target vessel.

[0005] In a first aspect of this disclosure, an ablation catheter is provided, comprising: an elongated strip including a distal segment capable of extending into the lumen of a blood vessel; an ablation electrode configured to circumferentially surround the distal segment of the elongated strip along its axial direction, wherein the ablation electrode is configured to have two ends with elastic structures and a middle segment connecting the two ends of the ablation electrode by a helical structure; and an infusion fluid outlet orifice disposed on the surface of the elongated strip.

[0006] Furthermore, the ablation electrode is made of an elastic conductive material, which allows the two ends of the ablation electrode to expand and be compressed and fastened to the outer surface of the distal section of the elongated strip.

[0007] Furthermore, the middle section of the aforementioned ablation electrode is constructed as a flat spiral structure.

[0008] Furthermore, when the two ends of the ablation electrode are configured to be compressed and fastened to the outer surface of the elongated strip, the outer circumferential dimensions of the two ends of the ablation electrode are smaller than the outer circumferential dimensions of the middle section of the ablation electrode.

[0009] Furthermore, the two ends of the ablation electrode are configured as a first end and a second end, and the junction of the first end and the second end with the middle section of the ablation electrode gradually changes from a small outer periphery to a large outer periphery.

[0010] Furthermore, the ablation electrode includes a first ablation electrode and a second ablation electrode. The first ablation electrode is positioned near the distal end of the distal segment of the elongated strip, and the second ablation electrode is positioned near the proximal end of the distal segment of the elongated strip.

[0011] Furthermore, a temperature sensor and an electrode wire are disposed on the outer surface of the distal section of the aforementioned elongated strip, wherein the temperature sensor and the electrode wire are disposed on the outer surface between the first ablation electrode and the second ablation electrode.

[0012] Furthermore, the flat spiral structure of the middle section of the ablation electrode extends from the first end to the second end with a thickness of 0.1-0.2 mm and a width of 0.4-0.8 mm, or the flat spiral structure of the middle section of the ablation electrode extends from the second end to the first end with a thickness of 0.1-0.2 mm and a width of 0.4-0.8 mm. A first connecting segment is provided at the circumferential half-circumference starting from the first end, connecting the first end axially, and a second connecting segment is provided at the circumferential half-circumference starting from the second end, connecting the second end axially.

[0013] Furthermore, the distal section of the aforementioned elongated strip has a tube with an internal structure, the internal structure of which includes multiple independent conduits.

[0014] In a second aspect of this disclosure, a method for manufacturing the ablation catheter is also provided. This method includes manufacturing the ablation electrode and assembling the ablation electrode, wherein a cylindrical tube of a certain length and wall thickness is formed using a nickel-titanium shape memory alloy.

[0015] This disclosure has the following advantages over the prior art:

[0016] (1) The ablation electrode with an axially circumferential structure can emit radiofrequency energy uniformly in the circumferential direction without requiring strong directivity. Furthermore, with a fixed contact area per unit length between the outer surface of the electrode and the blood vessel, the current density along the axis is uniform, resulting in consistent ablation intensity and depth. Furthermore, the flat spiral structure of the electrode allows the ablation catheter to have a certain amount of deformation recovery in the radial direction, providing strong adaptability to the target vessel diameter. Furthermore, specific connecting segments are established at the beginning of the flat spiral structure at both ends of the electrode, which can enhance the deformation recovery characteristics of the original structure, further enhancing the adaptability of the ablation catheter in the blood vessel without significantly affecting the ablation intensity per unit area. Furthermore, the ablation electrode adopts a compressible and fastening design at both ends, making the assembled ablation electrode more secure than glue connections.

[0017] (2) The internal conduit structure with multiple cavities can isolate the ablation signal transmission line and the thermal signal transmission line, improving their electrical stability. Furthermore, the multiple independent cavities make it easier to insert the wires into the conduit, avoiding entanglement.

[0018] (3) The temperature sensor arrangement with direct contact with the electrode can obtain temperature data more accurately and respond more quickly. Attached Figure Description

[0019] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. In the drawings, the same or similar reference numerals denote the same or similar components, wherein:

[0020] Figure 1 A schematic diagram of an ablation catheter body according to some embodiments of the present disclosure is shown;

[0021] Figure 2 A schematic diagram of an ablation electrode that mates with the ablation catheter body according to some embodiments of the present disclosure is shown;

[0022] Figure 3 A schematic diagram of an ablation electrode in conjunction with the ablation catheter body according to some embodiments of the present disclosure is shown from another perspective;

[0023] Figure 4 A schematic diagram of an ablation electrode in conjunction with the ablation catheter body according to some embodiments of the present disclosure is shown from another perspective;

[0024] Figure 5 A schematic diagram of an ablation catheter according to some preferred embodiments of the present disclosure is shown;

[0025] Figure 6 It shows Figure 5 Enlarged view of the ablation catheter in region A in the embodiment;

[0026] Figure 7 It shows Figure 1 A cross-sectional view of the ablation catheter body in the embodiment on the EE plane;

[0027] Figure 8 It shows Figure 1 Enlarged view of the ablation catheter body in region G in the embodiment;

[0028] Figure 9 A schematic diagram of an ablation electrode conforming to the ablation catheter body according to other embodiments of the present disclosure is shown; and

[0029] Figure 10 A schematic diagram of an ablation catheter being inserted into the human body according to some embodiments of the present disclosure is shown. Detailed Implementation

[0030] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0031] In the description of embodiments of this disclosure, the term "comprising" and similar terms should be understood as open-ended inclusion, i.e., "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0032] Furthermore, it should be noted that in the description of the embodiments of this application, unless otherwise explicitly defined, "in vivo" means inside the patient's tissues and organs, and "outside the body" means outside the patient's tissues and organs. Also, in the embodiments of this application, "distal" refers to the direction away from the physician, and "proximal" refers to the direction closer to the physician.

[0033] In existing technologies, visceral nerve ablation can effectively control the distribution of blood in internal organs and blood vessels, making it an important surgical method for treating various diseases. Currently, mainstream ablation technologies include radiofrequency ablation and ultrasound ablation. Radiofrequency ablation primarily relies on a radiofrequency therapy device with ablation and cutting functions, and its treatment mechanism is mainly based on thermal effects. When radiofrequency current flows through human tissue, the rapid changes in the electromagnetic field cause polarized water molecules within the tissue to move at high speed, generating heat (i.e., endogenous thermal effect). This causes the water inside and outside cells to evaporate, dry, shrink, and slough off, leading to aseptic necrosis, thereby achieving the therapeutic goal. However, existing technologies, with simple electrodes arranged circumferentially around the outer surface of the catheter body, present various problems. For example, electrodes are connected to the catheter body surface with glue, which has certain limitations in connection strength and carries a risk of detachment. Even with a circumferential structure, uneven spacing of the ring electrodes can result in excessively dense or sparse contact between the outer surface of the electrodes and blood vessels, affecting the uniformity of the current density along the ablation electrode axis and leading to uneven local ablation intensity and depth. For example, there's the issue of inconsistent axial stiffness at both ends of a single electrode, particularly around the starting or ending points. In cases where the electrode material is insufficient, leading to inconsistent axial stiffness, the electrode, along with the catheter, may "break" under certain bending conditions, losing its bending recovery ability. This can result in blockage of the internal perfusion channel and the risk of lead breakage. Furthermore, if leads within the catheter share the same cavity as the blood, it can cause electrical signal interference, lead entanglement, and biocompatibility issues.

[0034] To address at least one of the aforementioned problems, and one or more other potential problems, exemplary embodiments of this disclosure propose a novel ablation catheter comprising: an elongated strip including a distal segment capable of extending into the lumen of a blood vessel; an ablation electrode configured to axially surround the distal segment of the elongated strip, wherein the ablation electrode is configured with two ends having elastic structures and a middle segment connecting the two ends of the ablation electrode by a helical structure; and an infusion fluid outlet orifice disposed on the surface of the elongated strip.

[0035] Figure 1A schematic diagram of an ablation catheter body according to some embodiments of the present disclosure is shown. In this example embodiment, the ablation catheter body is divided into three segments: an ablation segment 11, a transition segment 12, and a braided reinforcement segment 13. As shown, the ablation catheter body is an elongated strip, which includes the ablation segment 11 (i.e., the distal segment at the distal end of the catheter body) that can extend into the lumen of a blood vessel, and is also the segment close to the head of the entire catheter body. The surface of the ablation segment 11 is constructed with uniformly distributed cavities for cooling the outflow of perfusion fluid, and corresponding ablation electrodes, electrode leads, and temperature sensors can also be arranged on the surface of the ablation segment 11. Therefore, the ablation segment 11 is the part or component emphasized in the various embodiments of the present disclosure. It should be noted that the length of the ablation segment 11 is preferably 10-15 mm.

[0036] Figure 2 A schematic diagram of an ablation electrode conforming to an ablation catheter body according to some embodiments of the present disclosure is shown. In this exemplary embodiment, to achieve circumferential ablation, the ablation electrode can be configured to circumferentially surround the distal segment of the elongated strip along its distal segment. More specifically, for ease of independent manufacturing and secure assembly, the ablation electrode can be constructed with elastic ends; and for diameter adaptability in blood vessels, the middle segment connecting the two ends of the ablation electrode is achieved through a helical structure. Furthermore, to enhance the secure assembly of the ablation electrode, particularly its fit with the ablation catheter body, the ablation electrode is made of an elastic conductive material (e.g., a nickel-titanium shape memory alloy), allowing the two ends of the ablation electrode to expand slightly, thus facilitating its insertion onto the outer surface of the ablation catheter body in an initial relaxed state. Simultaneously, to allow the ablation electrode to be compressed and secured to the outer surface of the distal segment of the ablation catheter body, the two ends of the ablation electrode are secured to the outer surface of the ablation catheter body by compression, resulting in a stronger connection than using adhesive bonding. More preferably, in order to further adapt the function of the two ends of the ablation electrode for fastening to the outer surface of the ablation catheter body, the two ends are formed by radially removing material to form radially open grooves or radially hollow grooves, so that when the two ends are squeezed in the axial direction, there are channels or gaps that can be squeezed. Otherwise, the two ends of the electrode will not be easy to compress, or will deform and not be tight after being compressed, or even cannot achieve effective fastening.

[0037] Figure 3A schematic diagram of an ablation electrode conforming to the ablation catheter body according to some embodiments of the present disclosure is shown from another perspective. It should be noted that the illustrated ablation electrode's ends are shown compressed and secured to the outer surface of the elongated strip-shaped body. In the example embodiment shown, to increase the contact area against the vessel wall, the middle section of the ablation electrode is constructed as a flattened spiral structure, while the ends of the ablation electrode are constructed with a smaller outer perimeter than the middle section. That is, during ablation, the middle section of the ablation electrode is primarily in contact with the vessel wall, and the smaller outer perimeter at the ends makes it less likely to directly contact the vessel wall, thus preventing the contact area of ​​the ablation electrode against the vessel wall from being excessively large locally. More preferably, if the two ends of the ablation electrode are configured as a first end and a second end, then the junction between the first end and the second end and the middle section of the ablation electrode exhibits a gradual change from a small outer perimeter to a large outer perimeter. This gradual change is due to the gradual change in the structure of the connection end caused by the compression of the two ends of the ablation electrode, and also facilitates the construction and arrangement of radially arranged, compression-friendly end radially hollowed structures 32 at both ends of the ablation electrode. More preferably, each end of the ablation electrode has four symmetrically arranged end radially hollowed structures 32. As shown in the figure, the end radially hollowed structure 32 is a section of structure located at both ends of the ablation electrode, extending from the end face towards the middle section, and having the tube wall material removed.

[0038] In some alternative embodiments, when the middle section of the ablation electrode adopts a flat helical structure, the radial width of the electrode material is increased at the junction of the middle section and both ends of the electrode, i.e., at the beginning or end of the flat helical structure of the middle section, to ensure structural strength. This not only leads to poor elastic deformation capacity of the electrode in all directions, but also causes uneven axial current density and even uneven ablation intensity and depth due to the excessively large local area of ​​the electrode's outer surface. Therefore, to ensure that the middle section of the flat helical structure of the ablation electrode in contact with the blood vessel wall has a uniform axial current density, and to ensure as much uniform ablation intensity and depth as possible at the contact point between the outer surface of the ablation electrode and the blood vessel wall, a method such as... Figure 3 The hollowed-out structure 30 in the middle section shown helps to control the ablation depth and ablation range.

[0039] Figure 4 A schematic diagram from another perspective is shown of an ablation electrode that mates with the ablation catheter body according to some embodiments of the present disclosure. It should be noted that... Figure 4 yes Figure 3The figure shows a view of the ablation electrode rotated axially at another angle. In the example embodiment shown in the figure, to address the issue of inconsistent axial stiffness of the ablation electrode near both ends, particularly due to insufficient material in the structure formed by the aforementioned hollow structure 30 in the middle section, which could lead to "breakage" of the ablation electrode and the corresponding section of the ablation catheter under certain bending conditions, resulting in loss of bending recovery ability, potentially causing blockage of the infusion channel inside the ablation catheter and the risk of wire breakage. Therefore, in a preferred embodiment, the flat spiral structure of the middle section of the ablation electrode begins with a thickness of 0.1-0.2 mm and a width of 0.4-0.8 mm and extends around from one end to the other. Near the point where the extension rotates 180 degrees (i.e., half a circumference) from one end, a connecting segment 31 (or reinforcing segment) is provided axially to connect to the starting end. Generally and symmetrically, another connecting segment is also provided axially to connect to the other end near the point where the extension rotates half a circumference from the other end. It should be noted that without the connecting segment, applying a certain degree of bending load to the ablation electrode structure results in very high stress in the middle section of the ablation electrode, i.e., the starting point of the helical feature structure. This means that the risk of "breakage" under actual use is very high. With the connecting segment, under the same bending load condition and with the addition of the connecting strip, the maximum stress point shifts to the connecting segment, while the stress value at the starting point of the helical feature structure is negligible compared to when the connecting segment is not added. More preferably, to obtain better compliance while maintaining axial connection stiffness, a radial through groove is also provided on this connecting segment. Most preferably, to balance strength and compliance, the dimension of the connecting strip should preferably occupy 4% of the entire circumference (e.g., the circumferential width) in the circumferential direction.

[0040] Figure 5A schematic diagram of an ablation catheter according to some preferred embodiments of the present disclosure is shown. To facilitate the placement of temperature sensors on the outer surface of the ablation catheter that can directly contact the ablation electrodes, enabling faster and more accurate acquisition of temperature data on the surface of the ablation catheter and thus a more timely response, in the example embodiment shown in the figure, two ablation electrodes of the aforementioned structure are disposed on the outer surface of the ablation segment (distal section) of the ablation catheter body. An adhesive-filled area is provided between the two ablation electrodes (i.e., between the ends of the two ablation electrodes), precisely at the inwardly recessed ends of the two ablation electrodes used for fastening. The outer surface of the ablation catheter between the two ends can then lead out temperature sensors that directly contact the ends of the ablation electrodes, as well as corresponding electrode leads. This arrangement is more compact and can also partially fill the "concave" shaped feature in the middle, resulting in better axial dimensional consistency of the ablation catheter and improving its passability within blood vessels. Furthermore, in the attached diagram, the head (i.e., distal end) of the ablation catheter is provided with the ablation catheter body 1 and the inner guidewire tube 6 for inserting the guidewire. The concave structural area between the two ablation electrodes 3 can be used to encapsulate the temperature sensor and the wire within it using adhesive 7. More specifically, in the enlarged schematic diagram of area A, as shown... Figure 6 As shown, the electrode wire 4, extending from the ablation catheter body, can directly connect to (contact with) the end of the ablation electrode. Therefore, the end of the ablation electrode not only serves to securely compress the ablation electrode to the surface of the ablation catheter body, but also facilitates the direct connection and contact of the electrode wire 4. Furthermore, the temperature sensor 5 is also extended from the ablation catheter body in this concave structural area and directly contacts the ablation electrode, facilitating accurate and timely acquisition of temperature data. This entire concave structural area can be encapsulated with adhesive 7, and the outer periphery of the encapsulated concave structural area is essentially the same as the outer periphery of the middle section of the ablation electrode. In addition, in the illustrated embodiment, the two ends of the ablation electrode 3 have strip grooves 33 to facilitate the compression and securing of both ends to the surface of the ablation catheter body.

[0041] Figure 7 It shows Figure 1The figure shows a cross-sectional view of the ablation catheter body on the EE plane. In the example embodiment shown in the figure, the cavity 100 for cooling the outflow of the perfusion fluid is connected to the perfusion fluid channel cavity 101 inside the ablation catheter body. The placement channel 104 for arranging electrode wires and the placement channel 105 for arranging temperature sensors and their wires each have independent channel chambers. This arrangement of internal chambers can isolate the wires in the ablation catheter from human blood, which helps to ensure biocompatibility. Furthermore, the wire channels in the ablation catheter are evenly arranged on the outside of the ablation catheter, which can isolate the wires to the greatest extent, improve the electrical insulation between the different types of wires arranged in the ablation catheter, and prevent mutual electrical interference and unwanted entanglement between the wires as much as possible.

[0042] Figure 8 It shows Figure 1 An enlarged view of the ablation catheter body in region G of the embodiment. In the example embodiment of this figure, the infusion fluid outflow holes (i.e., the cavities 100 for cooling the outflow of infusion fluid) are uniformly or equally spaced on the outer surface of the elongated strip (the ablation catheter body).

[0043] Figure 9 A schematic diagram of an ablation electrode conforming to the ablation catheter body according to other embodiments of the present disclosure is shown. In the example embodiment of the figure, the two ends of the ablation electrode are not yet compressed or squeezed. As can be seen from the figure, in addition to having an open groove segment starting from the end and facing the middle end, the two ends also have several radially hollowed-out groove segments evenly arranged in the circumferential direction to facilitate compression and fastening of the two ends to the surface of the ablation catheter body.

[0044] Figure 10 A schematic diagram of an ablation catheter being inserted into the human body according to some embodiments of the present disclosure is shown. Figure 10 As shown, in some embodiments, the ablation catheter 10 is delivered to the target location via a cooperating guide tube 25, for example, through the location between the thoracic spine T9 and thoracic spine T10, to the bend in the target location.

[0045] Furthermore, due to the special structure of the ablation electrode in each embodiment of this disclosure, it has a different manufacturing process than existing spring structures. Therefore, the corresponding ablation electrode in this disclosure has two compressible fastening ends and a flat helical structure in the middle section. A special manufacturing method is provided for this ablation electrode. Specifically, the method includes: using a shape memory alloy (preferably a nickel-titanium shape memory alloy) to make a cylindrical tube of a given thickness, preferably 0.1-0.2 mm. The axial (meridian) length of the cylindrical tube is preferably 8-15 mm, and the circumferential diameter is preferably 3-5 mm. Preferably, the cylindrical tube has a smooth (or polished) outer surface and an inner surface. Using laser cutting technology, the middle section of the cylindrical tube is cut into a flat helical structure, such that the flat helical structure is constructed as a spring-like structure connecting two ends near the opening. Preferably, the remaining section of the flat helical structure after cutting becomes the middle section of the ablation electrode. Furthermore, in the flat spiral structure section of the middle section of the ablation electrode, the radial width of the electrode is preferably 0.4-0.8 mm. Further, the sum of the width of the radial shape memory alloy section of the electrode and the width of the radial hollow section of the electrode is preferably 1.75 mm. Such an interval setting can meet the ablation current density setting of the affected area, and also facilitates the bending and recovery of the entire ablation catheter (especially the ablation electrode section) in the blood vessels of the patient. The two ends of the cylindrical tube are set as radial hollow grooves and / or open grooves, so that the two ends of the cylindrical tube can be compressed or squeezed to facilitate the cylindrical tube itself being fastened to the surface of the ablation catheter body.

[0046] Furthermore, to accommodate the assembly process of the ablation electrode, it is generally assembled by squeezing / compressing both ends. This makes the outer periphery of the two ends of the ablation electrode after compression or squeezing significantly smaller than the outer periphery of the middle section of the ablation electrode. As a result, the discrete ablation electrodes are more firmly attached to the outer surface of the ablation catheter body than by glue.

[0047] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

[0048] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. An ablation catheter, characterized in that, include: A slender strip-shaped body, the slender strip-shaped body including a distal segment capable of extending into the lumen of a blood vessel; An ablation electrode is configured to surround the distal segment of the elongated strip along its axial direction, wherein the ablation electrode is constructed to have two ends with elastic structures and a middle segment connecting the two ends of the ablation electrode by a helical structure. The ablation electrode has both ends and a middle section made of an elastic conductive material. The ablation electrode is configured to be fixed to the outer surface of the ablation catheter body through the two ends. The outer circumference of the two ends is smaller than that of the middle section, and the middle section is configured to maintain a distance from the outer surface of the ablation catheter body. The two ends of the ablation electrode are manufactured by radially removing material and formed into radially open grooves or radially hollow grooves, so that when the two ends of the ablation electrode are squeezed in the axial direction, there are channels or gaps that can be squeezed. An injection fluid outlet hole is provided on the surface of the elongated strip.

2. The ablation catheter according to claim 1, characterized in that, The two ends of the ablation electrode are configured to expand and be compressed and secured to the outer surface of the distal section of the elongated strip.

3. The ablation catheter according to claim 1, characterized in that, The middle section of the ablation electrode is constructed as a flat spiral structure.

4. The ablation catheter according to claim 1, characterized in that, When the two ends of the ablation electrode are configured to be compressed and fastened to the outer surface of the elongated strip, the outer circumferential dimensions of the two ends of the ablation electrode are smaller than the outer circumferential dimensions of the middle section of the ablation electrode.

5. The ablation catheter according to claim 4, characterized in that, The two ends of the ablation electrode are configured as a first end and a second end. The junction between the first end and the second end and the middle section of the ablation electrode gradually changes from a small outer periphery to a large outer periphery. Each of the two ends of the ablation electrode is provided with four symmetrically arranged radially hollowed-out end structures.

6. The ablation catheter according to claim 1, characterized in that, The ablation electrode includes a first ablation electrode and a second ablation electrode. The first ablation electrode is positioned near the distal end of the distal segment of the elongated strip, and the second ablation electrode is positioned near the proximal end of the distal segment of the elongated strip.

7. The ablation catheter according to claim 6, characterized in that, A temperature sensor and an electrode wire are disposed on the outer surface of the distal section of the elongated strip, wherein the temperature sensor and the electrode wire are disposed on the outer surface between the first ablation electrode and the second ablation electrode.

8. The ablation catheter according to claim 5, characterized in that, The flat spiral structure of the middle section of the ablation electrode starts from the first end and extends around to the second end with a thickness of 0.1-0.2 mm and a width of 0.4-0.8 mm, or the flat spiral structure of the middle section of the ablation electrode starts from the second end and extends around to the first end with a thickness of 0.1-0.2 mm and a width of 0.4-0.8 mm. A first connecting segment is provided axially to the first end, extending around half a circumference from the first end, and a second connecting segment is provided axially to the second end, extending around half a circumference from the second end.

9. The ablation catheter according to claim 1, characterized in that, The distal section of the elongated strip has a tube with an internal structure, the internal structure of which includes multiple independent conduits.

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