Ablation microcatheter

Abstract

The invention relates to an ablation microcatheter. The ablation microcatheter comprises a base, an inner tube, a flexible circuit belt, a supporting tube, an outer tube, a plurality of electrode rings, an end and a driving mechanism. The base is provided with an inner cavity; the inner pipe is communicated with the inner cavity; the flexible circuit belt is wound outside the inner pipe and spirally extends in the axial direction of the inner pipe, the flexible circuit belt comprises a bonding layer, an adhesion layer and a plurality of electrode plates, the bonding layer is connected with the adhesion layer, the bonding layer is located on the side, facing the inner pipe, of the adhesion layer, and the electrode plates are distributed on the face, back to the bonding layer, of the adhesion layer at intervals; the electrode plate spirally extends along the axial direction of the inner tube; the inner pipe is sleeved with the outer pipe, and the flexible circuit belt is located in the outer pipe. The electrode rings sleeve the outer tube at intervals and are electrically connected with the electrode plates; the driving mechanism is installed on the base and drives the inner pipe to be bent. According to the scheme, it can be ensured that after the inner tube is bent for multiple times, the electrode plates and the electrode rings are still tightly connected.

Description

Technical Field

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

[0002] Cardiac catheter ablation is a procedure that uses a catheter to be inserted through the groin or neck area. Electrodes at the tip of the catheter help doctors detect electrophysiological properties and determine the location of abnormal electrical signals. Once the exact location is determined, doctors can deliver energy through the catheter to ablate the local area.

[0003] Catheter ablation technology has been widely used in the clinical ablation of various arrhythmias, such as atrial fibrillation, premature ventricular contractions, and ventricular tachycardia. With the deepening of the understanding of the mechanism of arrhythmias and the continuous improvement of ablation devices, the success rate of catheter ablation of arrhythmias has been significantly improved. However, due to the limitations of ablation devices currently on the market, the success rate of ablation of some arrhythmias is limited. The most prominent performance is the catheter ablation treatment of persistent atrial fibrillation, premature ventricular contractions, and ventricular tachycardia.

[0004] First, in recent years, it has been found that the Marshall vein plays an important role in the occurrence and maintenance of persistent atrial fibrillation. The Marshall vein is one of the triggering foci of atrial fibrillation; there is a rich distribution of autonomic nerves on the Marshall vein / ligament; it plays an auxiliary role in the isolation of the left pulmonary vein and the linear block of the mitral isthmus. At present, most of the clinical ablation of the corresponding area is achieved through alcohol perfusion of the Marshall vein, but this method still has limitations: 1. During the ablation process, the determination that the Marshall vein is the triggering foci of atrial fibrillation is based on indirect evidence, and there is no direct evidence to determine the accurate mechanism. 2. Alcohol perfusion of the Marshall vein is non-selective, and the damaged myocardium is closely related to the distribution of the Marshall vein and its branch vessels. The process of alcohol perfusion is uncontrollable, while microcatheter can achieve precise ablation. 3. There is communication between the Marshall vein and the left atrium and even the superior vena cava. During the perfusion process, alcohol entering these parts can damage the endothelium and increase the risk of thrombosis.

[0005] To this end, ablation catheters are available on the market that use electrode rings to generate high-voltage pulse energy to the target tissue to achieve effective ablation. The rigid electrode rings and rigid wires are bonded together by welding. The positions of the electrode rings and the wires in the catheter are relatively fixed after assembly. However, during actual clinical use, in order to enable the ablation catheter to adapt to the patient's vascular shape and the different locations to be reached in various shapes, the handle end of the ablation catheter is controlled to make the head end pipeline bend into different shapes, which is bound to bring different degrees of bending effects to different electrode rings of the head end pipeline. Since the electrode and the wire are connected by welding, the electrode ring and the wire are likely to fall off from each other after multiple bendings, and the ablation catheter will lose its original function after falling off. Summary of the invention

[0006] In order to solve or partially solve the problems existing in the related art, the present application provides an ablation microcatheter that can improve the structural strength of the inner tube.

[0007] The first aspect of the present application provides an ablation microcatheter, comprising a base, an inner tube, a flexible circuit belt, a support tube, an outer tube, a plurality of electrode rings and a driving mechanism; the base is provided with an inner cavity; the inner tube is connected to the inner cavity; the flexible circuit belt is outside the inner tube, and the flexible circuit belt extends in an axial spiral along the inner tube, the flexible circuit belt comprises an adhesive layer, an attachment layer and a plurality of electrode sheets, the adhesive layer and the attachment layer are connected, the adhesive layer is located on a side of the attachment layer facing the inner tube, a plurality of the electrode sheets are distributed at intervals on a side of the attachment layer facing away from the adhesive layer, and the electrode sheets extend in an axial spiral along the inner tube; the outer tube is sleeved outside the inner tube, and the flexible circuit belt is located inside the outer tube; the electrode rings are sleeved outside the outer tube at intervals, the electrode rings correspond to the electrode sheets one by one, and the electrode rings are electrically connected to the electrode sheets; the driving mechanism is installed on the base, and the driving mechanism drives the inner tube to bend.

[0008] Furthermore, the ablation microcatheter also includes a connector and a connecting tube, two ends of the connecting tube are respectively connected to the connector and the base, and one end of the electrode sheet is electrically connected to the connector.

[0009] Furthermore, the flexible circuit belt also includes a reinforcement layer, which corresponds to the electrode sheet one by one, and the reinforcement layer is wound on the outer surface of the outer tube. One end of the reinforcement layer passes through the outer tube and is connected to the electrode sheet. The electrode ring abuts against the reinforcement layer and is electrically connected to the reinforcement layer.

[0010] Furthermore, the inner tube is provided with a first guide wire cavity, the first guide wire cavity is communicated with the inner cavity, and the end of the base facing away from the inner tube is provided with a through hole, the through hole is communicated with the inner cavity.

[0011] Furthermore, the inner tube is provided with a second guide wire cavity, the outer tube is provided with an outer through hole, the inner tube is provided with an inner through hole corresponding to the outer through hole, and the outer through hole is connected with the second guide wire cavity through the inner through hole.

[0012] Furthermore, the ablation microcatheter also includes a support tube, which is sleeved outside the inner tube and is used to reinforce the inner tube.

[0013] Furthermore, the ablation microcatheter further comprises a tip, the tip being connected to an end of the inner tube away from the base, and the hardness of an end of the support tube close to the tip gradually decreases toward the tip.

[0014] Furthermore, the inner tube is provided with an infusion cavity, which is communicated with the inner cavity, and the end is provided with a liquid outlet hole, which is communicated with the liquid outlet hole.

[0015] Furthermore, the hardness of the end tip gradually decreases in a direction away from the inner tube.

[0016] Furthermore, the electrode ring includes an electrode member and an adhesion layer, the electrode member includes an inner layer and an outer layer, the outer layer surrounds the inner layer, the inner layer is connected to the outer layer, the inner layer is electrically connected to the electrode sheet, and the outer layer is bonded to the outer tube through the adhesion layer.

[0017] The technical solution provided by the present application may include the following beneficial effects: by arranging a support tube outside the inner tube and reinforcing the inner tube with the support tube, the strength of the ablation microcatheter at the position of the inner tube is improved, thereby preventing the ablation microcatheter from breaking when bending and stretching in the blood vessel.

[0018] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other objects, features and advantages of the present application will become more apparent by describing in more detail exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0020] Figure 1 is a schematic structural diagram of an ablation microcatheter shown in an embodiment of the present application;

[0021] Figure 2 yes Figure 1 A is an enlarged schematic diagram;

[0022] Figure 3 It is a schematic diagram of the connection between the electrode sheet and the electrode ring;

[0023] Figure 4 is a cross-sectional view of a flexible circuit strip;

[0024] Figure 5 is a cross-sectional view of the electrode ring;

[0025] Figure 6 It is a schematic diagram of the structure of the driving mechanism;

[0026] Figure 7 It is a structural schematic diagram of the OTW structure of the ablation microcatheter of the present application.

[0027] Figure numerals: base 1; inner tube 2; support tube 3; outer tube 4; outer through hole 41; electrode ring 5; outer layer 51; inner layer 52; adhesive layer 53; terminal 6; connector 7; connecting tube 8; flexible circuit tape 9; adhesive layer 91; attachment layer 92; electrode sheet 93; reinforcement layer 94; driving mechanism 10; pull wire 101; slider 102; push handle 103. DETAILED DESCRIPTION

[0028] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0029] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0030] In the description of the present application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0031] Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, or 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, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] In view of the above problems, an embodiment of the present application provides an ablation microcatheter that can improve the structural strength of the inner tube.

[0033] The technical solution of the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0034] Figure 1 is a schematic structural diagram of an ablation microcatheter shown in an embodiment of the present application; Figure 5 is a cross-sectional view of the electrode ring; Figure 6 It is a structural diagram of the driving mechanism.

[0035] See also Figure 1 , Figure 5 and Figure 6 The ablation microcatheter includes a base 1, an inner tube 2, an outer tube 4, a plurality of electrode rings 5, a terminal 6, a flexible circuit belt 9 and a driving mechanism 10. The base 1 is provided with an inner cavity, through which a contrast agent, a guide wire or other detection equipment can pass. The inner tube 2 is connected to the inner cavity, and when a guide wire is needed, the guide wire can be extended from the inner cavity into the inner tube 2; when a contrast agent needs to be introduced into the inner tube 2, the contrast agent can flow from the inner cavity into the inner tube 2.

[0036] Figure 3 It is a schematic diagram of the connection between the electrode sheet and the electrode ring.

[0037] See also Figure 3 and Figure 5 The flexible circuit belt is outside the inner tube 2. The flexible circuit belt 9 includes an adhesive layer 91, an adhesive layer 92 and a plurality of electrode sheets 93. The adhesive layer 91 and the adhesive layer 92 are adhered to each other. The adhesive layer 91 and the adhesive layer 92 are both made of insulating materials. The adhesive layer 91 is located on the side of the adhesive layer 92 facing the inner tube. A plurality of electrode sheets 93 are distributed at intervals on the side of the adhesive layer 92 facing away from the adhesive layer 91. The adhesive layer 91 extends along the axial spiral of the inner tube 2. The adhesive layer 92 extends along the axial spiral of the inner tube 2. The electrode sheets 93 are attached to the surface of the adhesive layer 92. The electrode sheets extend along the axial spiral of the inner tube 2. When the inner tube 2 bends, the electrode sheets 93 will also bend accordingly. Since two adjacent electrode sheets 93 are spaced apart, no short circuit will occur between the two adjacent electrode sheets 93. The outer tube 4 is made of a polymer material. The outer tube 4 is sleeved outside the inner tube 2. The flexible circuit belt is located inside the outer tube 4. The outer tube 4 can protect the flexible circuit belt 9.

[0038] Figure 2 yes Figure 1 A is an enlarged schematic diagram; Figure 4 is a cross-sectional view of a flexible circuit ribbon.

[0039] See also Figure 1-5, multiple electrode rings 5 ​​are sleeved outside the outer tube 4 at intervals along the axial direction of the outer tube 4, the number of electrode rings 5 ​​corresponds to the number of electrode sheets 93, the lengths of any two electrode sheets 93 are inconsistent, and each electrode ring 5 is electrically connected to only one of the electrode sheets 93. When the electrode sheet 93 reaches the position where the corresponding motor ring 5 is located, it is electrically connected to the electrode ring 5. At this time, the electrode sheet 93 no longer continues to extend along the axial direction of the inner tube 2, and the remaining electrode sheets 93 continue to extend along the axial direction of the inner tube 2 until they reach the corresponding electrode ring 5. When the electrode is needed for ablation, the electrode will be energized, and an electric field will be formed between two adjacent electrodes, wherein different electric field strengths will be obtained by changing the voltage or the distance from the electrode. The material of the electrode ring 5 can be any suitable metal material, and the commonly used material is a platinum-iridium alloy or gold material electrode. Different electrode spacing and polarity combinations are designed according to actual needs. The electrode ring 5 passage can withstand a voltage of 4000V. Once the target catheter is positioned, the tail end is connected to the pulse transmitter and the high-voltage pulse energy can be effectively transmitted to the target tissue through the front electrode ring 5 to achieve effective ablation. The end 6 is connected to the end of the inner tube 2 away from the base 1. The end 6 is made of soft material. The inner diameter of the end 6 can be selected to fit a common coronary guidewire of 0.014". The end 6 can prevent the ablation microcatheter from puncturing the blood vessel when it is inserted into the blood vessel.

[0040] See also Figure 6 In some embodiments, the driving mechanism is mounted on the base 1, and the driving mechanism drives the inner tube 2 to bend. The driving mechanism 10 includes a pull wire 101, a slider 102, and a push handle 103. One end of the pull wire 101 is connected to the terminal 6, and the other end of the pull wire 101 is fixed to the base 1 through a lock. The slider 102 is fixed to the push handle 103, and the slider 102 is fixed to the outer tube 4. The push handle 103 can move relative to the base 1. When the user pushes the push handle 103 toward the terminal 6, the outer tube 4 and the inner tube 2 will bend, so that the outer tube 4 can be stretched in a winding manner in the blood vessel.

[0041] See also Figure 1 and Figure 3 The ablation microcatheter also includes a connector 7 and a connecting tube 8. The two ends of the connecting tube 8 are connected to the connector 7 and the base 1 respectively, and one end of the electrode sheet is electrically connected to the connector 7. The connector 7 can be connected to a multi-channel instrument or other instrument with the same function. The electrode ring 5 can simultaneously record in real time and transmit electrical signals to the connector 7 through the electrode sheet. The connector 7 displays the potential of the part where the electrode ring 5 is in contact in real time through an external instrument to help the operator judge the ablation situation.

[0042] See also Figure 2 and Figure 5The flexible circuit belt 9 also includes a reinforcement layer 94, the number of reinforcement layers 94 corresponds to the number of electrode sheets 93, the reinforcement layer 94 is wound on the outer surface of the outer tube 4, one end of the reinforcement layer 94 passes through the outer tube 4 and is connected to the electrode sheet 93, the reinforcement layer 94 and the electrode sheet 93 are an integral structure, the reinforcement layer 94 is made of a long strip of metal sheet, the metal sheet is wound around the outer surface of the outer tube for several turns to form the reinforcement layer 94, the electrode ring 5 is against the reinforcement layer 94 and wraps the reinforcement layer 94, the electrode ring 5 is electrically connected to the reinforcement layer 94, the electrode ring 5 is in large-area contact with the reinforcement layer 94, the electrode ring 5 is ensured to be in close contact with the reinforcement layer 94, and the electrode ring 5 and the electrode sheet 93 have good conductivity.

[0043] See also Figure 1 and Figure 5 The ablation microcatheter also includes a support tube 3. The inner tube 2 is made of a polymer material. The support tube 3 is sleeved on the outside of the inner tube 2. The support tube 3 may or may not be in contact with the inner tube 2. The support tube 3 is used to reinforce the inner tube 2, thereby improving the strength of the ablation microcatheter at the position where the inner tube 2 is located, and avoiding the ablation microcatheter from breaking when the ablation microcatheter is bent and stretched in the blood vessel. The outer tube 4 is sleeved on the outside of the support tube 3. Specifically, the outer tube 4 is attached to the outer surface of the support tube 3. The inner tube 2, the outer tube 4, and the support tube 3 can add an adjustable bending function. The adjustable bending design can be similar to the existing ten-level adjustable bending mapping catheter. The operator can operate the distal electrode ring 5 part through the handle to reach the target position to achieve a better adhesion effect. The reinforcement layer 94 passes through the support tube 3 and the outer tube 4 from the electrode sheet in sequence to the outer surface of the outer tube 4, wherein the reinforcement layer 94 and the support tube 3 need to be insulated. Specifically, the side of the reinforcement layer 94 facing the support tube can be coated with insulating paint. See Figure 5 In this embodiment, the flexible circuit tape is attached to the outside of the inner tube 2 through the adhesive layer 91. When the flexible circuit tape 9 is wound on the outer surface of the inner tube 2, the surface of the electrode sheet 93 needs to be insulated to prevent the electrode sheet 93 from short-circuiting with the support tube 3. In other embodiments, the flexible circuit tape 9 is attached to the outside of the support tube 3 through the adhesive layer 91.

[0044] Figure 7 It is a structural schematic diagram of the OTW structure of the ablation microcatheter of the present application.

[0045] See also Figure 7 In some embodiments, the ablation microcatheter is an OTW structure, the connector 7 is located on one side of the base 1, the connector 7 is not connected to the inner cavity, the inner tube 2 is provided with a first guidewire cavity, the first guidewire cavity is used to pass the guidewire, the first guidewire cavity is connected to the inner cavity, and a perforation is provided at one end of the base 1 facing away from the inner tube 2, the perforation is connected to the inner cavity, and the guidewire can pass through the perforation and the inner cavity in sequence to reach the first guidewire cavity.

[0046] See also Figure 1-3In some embodiments, the ablation microcatheter is an Rx structure, the inner tube 2, the base 1, and the connector 7 are in the same straight line, the inner tube 2 is provided with a second guidewire cavity, and the second guidewire cavity is used to pass the guidewire. The outer tube 4 is provided with an outer through hole 41, and the inner tube 2 is provided with an inner through hole corresponding to the outer through hole 41. The outer through hole 41 is connected to the second guidewire cavity through the inner through hole, and the guidewire can pass through the outer through hole 41 and the inner through hole in sequence, and then enter the second guidewire cavity 23.

[0047] In some embodiments, the inner tube 2 is provided with an infusion cavity, and no guide wire passes through the inner tube 2. The infusion cavity is connected to the inner cavity, and the end 6 is provided with a liquid outlet. The surface of the end 6 is smooth, and the infusion cavity is connected to the liquid outlet. The ablation microcatheter can directly reach the target position to complete ablation. When used, liquids such as contrast agents can be injected into the infusion cavity, and then ablation is achieved. At the same time, the contrast agent flows out of the liquid outlet and is infused around the electrode ring 5. The contrast agent can be physiological saline. Figure 1-3 In some embodiments, the hardness of one end of the support tube 3 close to the end 6 gradually decreases toward the end 6, and the distal end of the support tube 3 can be made gradually soft by mechanical processing, so that the support tube 3 can be bent in the blood vessel while ensuring sufficient strength, so that it can be stretched in a complex blood vessel. The support tube 3 is made of stainless steel, nickel-titanium alloy or polymer material, and the polymer material can be peek material.

[0048] See also Figure 1-2 In some embodiments, the hardness of the terminal 6 gradually decreases in the direction away from the inner tube 2, so that the end of the terminal 6 is soft enough to reduce the risk of puncturing the blood vessel when the terminal 6 is inserted into the blood vessel. Preferably, the terminal 6 can be made of a developing material, and when the terminal 6 is inserted into the blood vessel, the position of the terminal 6 and the inner tube 2 can be understood by taking X-rays.

[0049] See also Figure 2 and Figure 5 In some embodiments, the electrode ring 5 includes an electrode member and an adhesive layer 53. The cross section of the electrode member is T-shaped. The electrode member includes an inner layer 52 and an outer layer 51 formed integrally. The outer layer 51 surrounds the outer layer. The inner layer 52 is connected to the outer layer 51. The width of the outer layer 51 is larger than that of the inner layer 52. The inner layer 52 is electrically connected to the electrode sheet. The outer layer 51 is bonded to the outer tube 4 through the adhesive layer 53. The adhesive layer 53 is sandwiched between the outer tube 4 and the outer layer 51. This structure can ensure that the electrode member is electrically connected to the electrode sheet 93 while firmly fixing the electrode member on the outer tube 4. When the electrode ring 5 is unfolded, it is a long strip-shaped structure. When the electrode ring needs to be installed on the outer tube 4, one side of the adhesive layer 53 can be facing the surface of the outer tube 4, one end of the electrode ring 5 can be attached to the outer tube 4, and then the electrode ring 5 can be attached to the outer tube 4 by wrapping around the outer tube 4, so that the installation process of the motor ring 5 is simpler.

[0050] In some embodiments, the electrode ring 5 is an annular metal sheet, and the electrode ring 5 is welded to the outer surface of the outer tube 4 .

[0051] The scheme of the present application has been described in detail above with reference to the accompanying drawings. In the above embodiments, the descriptions of the various embodiments have their own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments. Those skilled in the art should also be aware that the actions and modules involved in the specification are not necessarily required for the present application. In addition, it can be understood that the steps in the method of the embodiment of the present application can be adjusted in order, merged and deleted according to actual needs, and the modules in the device of the embodiment of the present application can be merged, divided and deleted according to actual needs.

[0052] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. An ablation microcatheter, characterized in that: include: A base, wherein the base is provided with an inner cavity; an inner tube, the inner tube being in communication with the inner cavity; A flexible circuit belt, the flexible circuit belt is outside the inner tube and extends in an axial spiral along the inner tube, the flexible circuit belt comprises an adhesive layer, an adhesion layer and a plurality of electrode sheets, the adhesive layer is connected to the adhesion layer, the adhesive layer is located on a side of the adhesion layer facing the inner tube, a plurality of electrode sheets are spaced and distributed on a side of the adhesion layer facing away from the adhesive layer, and the electrode sheets extend in an axial spiral along the inner tube; An outer tube, wherein the outer tube is sleeved outside the inner tube, and the flexible circuit belt is located inside the outer tube; A plurality of electrode rings, the electrode rings are sleeved outside the outer tube at intervals, the electrode rings correspond to the electrode sheets one by one, and the electrode rings are electrically connected to the electrode sheets; A driving mechanism is installed on the base, and the driving mechanism drives the inner tube to bend.

2. The ablation microcatheter according to claim 1, characterized in that: It also includes a connector and a connecting tube, wherein two ends of the connecting tube are respectively connected to the connector and the base, and one end of the electrode sheet is electrically connected to the connector.

3. The ablation microcatheter according to claim 1, characterized in that: The flexible circuit belt also includes a reinforcement layer, which corresponds to the electrode sheet one by one. The reinforcement layer is wound on the outer surface of the outer tube, one end of the reinforcement layer passes through the outer tube and is connected to the electrode sheet, and the electrode ring abuts against the reinforcement layer and is electrically connected to the reinforcement layer.

4. The ablation microcatheter according to claim 1, characterized in that: The inner tube is provided with a first guide wire cavity, which is communicated with the inner cavity; an end of the base facing away from the inner tube is provided with a through hole, which is communicated with the inner cavity.

5. The ablation microcatheter according to claim 1, characterized in that: The inner tube is provided with a second guide wire cavity, the outer tube is provided with an outer through hole, the inner tube is provided with an inner through hole corresponding to the outer through hole, and the outer through hole is connected with the second guide wire cavity through the inner through hole.

6. The ablation microcatheter according to claim 1, characterized in that: It also includes a support tube, which is sleeved outside the inner tube and is used to reinforce the inner tube.

7. The ablation microcatheter according to claim 6, characterized in that: It also includes an end head, which is connected to an end of the inner tube away from the base, and the hardness of an end of the support tube close to the end head gradually decreases toward the end head.

8. The ablation microcatheter according to claim 7, characterized in that: The inner tube is provided with an infusion cavity, which is communicated with the inner cavity; the end is provided with a liquid outlet, which is communicated with the liquid outlet.

9. The ablation microcatheter according to claim 7, characterized in that: The hardness of the end tip gradually decreases in a direction away from the inner tube.

10. The ablation microcatheter according to claim 1, characterized in that: The electrode ring includes an electrode member and an adhesive layer. The electrode member includes an inner layer and an outer layer. The outer layer surrounds the inner layer. The inner layer is connected to the outer layer. The inner layer is electrically connected to the electrode sheet. The outer layer is bonded to the outer tube through the adhesive layer.

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