CN117958828A

CN117958828A - Electrophysiology mapping catheter

Info

Publication number: CN117958828A
Application number: CN202410260393.3A
Authority: CN
Inventors: 刘立杰; 景致; 章湘明; 阴杰
Original assignee: Suzhou Aikemai Medical Technology Co ltd
Current assignee: Suzhou Aikemai Medical Technology Co ltd
Priority date: 2024-03-07
Filing date: 2024-03-07
Publication date: 2024-05-03

Abstract

The application discloses an electrophysiology mapping catheter, which comprises a catheter body and electrode branches arranged at the far end of the catheter body, wherein a plurality of electrode branches are arranged along the circumference of the catheter body, and the electrode branches extend from the connection position with the catheter body in the direction away from the catheter body; the electrode branch includes a curved first bend located at a position where the electrode branch is farthest from the catheter. After being combined with adjacent ring electrode signals, the mapping with larger area and higher precision can be realized.

Description

Electrophysiology mapping catheter

Technical Field

The application relates to the field of medical instruments, in particular to an electrophysiology mapping catheter.

Background

In the field of electrophysiology catheters, mapping catheters are commonly used to support stimulation and map electrical signal activity of the heart chambers, atria, atrial septum, etc., and from the collected electrical signals, a mapping map is formed. Currently, the existing unipolar or claw-shaped mapping catheter has small application area (single electrode mapping), or commonly has the problem that the head end easily touches endocardial tissue, so that premature beat occurs, and diagnosis and treatment in operation are affected, so that the design of large-area high-density, good and stable signal transmission and soft contact points is important for reducing the occurrence of premature beat and immediate diagnosis and treatment in operation.

Disclosure of Invention

In order to solve the problems in the prior art, the application provides an electrophysiology mapping catheter.

The specific technical scheme of the application is as follows:

an electrophysiology mapping catheter comprises a catheter body and electrode branches arranged at the distal end of the catheter body, wherein a plurality of electrode branches are arranged along the circumference of the catheter body, and the electrode branches extend from a position connected with the catheter body in a direction away from the catheter body;

The electrode branch includes a curved first bend located at a position where the electrode branch is farthest from the catheter.

In one embodiment, the first bend is curved in a plane proximate the vertical tubular body.

In one embodiment, the electrode branch includes a second curved portion at a position of the electrode branch near the tube body, the second curved portion being curved toward a direction away from the central axis of the catheter.

In one embodiment, both ends of the electrode branch extend from the first bending portion toward the direction approaching the pipe body.

In a specific embodiment, the pipe body is of a hollow structure, a pull rod is connected inside the pipe body in a sliding manner, and one end of the electrode branch is fixedly connected to the far end of the pull rod; one end of the electrode branch, which is far away from the pull rod, is fixedly connected on the pipe body.

In one embodiment, the electrode branches are curved annularly in the radial direction of the shaft when the distal end of the pull rod moves closer to the distal end of the shaft.

In one embodiment, the plane in which the loop of the electrode branches is formed tends to be perpendicular to the plane of the tie rod.

In one embodiment, the end of the electrode branch away from the tube body is a free end.

In one embodiment, the free ends of the electrode branches extend in a direction approaching the tube body; the electrode branches are annular.

In a specific embodiment, ring electrodes that can be used for mapping are provided on the electrode branches.

Advantageous effects

The electrophysiology mapping catheter of the application travels in a sheath tube in a bundle-shaped structure during delivery, and after reaching a designated heart region, the electrode branches are unfolded into petal shapes by pulling a pull rod (if any) arranged in the middle or naturally unfolding the electrode branches through a shaped memory skeleton in the electrode branches. The petal locus is attached with the ring electrode, and the ring electrode provides higher-density signal transmission under the same operation time. The deployed structure may be in the heart in a structural style of at least two petals and four petals. The maximum extension of the unfolded single petals is in an arc-shaped structure; the contact mode of the head end of the arc-shaped extension design relative to a single catheter can realize better adhesion and better reduce the occurrence of premature beat probability. The petal structure of each electrode branch is provided with a plurality of ring electrodes for mapping micro-small electric signals, each petal-shaped electrode branch is relatively independent and is equivalent to a single independent ring electrode, and after the petal-shaped electrode branches are combined with adjacent ring electrode signals, mapping with larger area and higher precision can be realized; the branches are fixed after being unfolded and the head ends are connected, so that the disadvantage of premature beat of the unipolar mapping or star mapping catheter is overcome.

The electrode branches are in smooth contact with the inner wall of the heart on the premise of ensuring the abutting effect when the catheter is used for marking, so that the occurrence of premature beat can be effectively reduced;

drawings

FIG. 1 is a schematic view of a catheter structure of the present application;

FIG. 2 is an enlarged schematic view of a portion of a catheter of the present application;

Fig. 3 is a schematic view of a catheter structure according to another embodiment of the present application.

In the figure, 1, a pipe body; 2. an electrode branch; 3. a first bending portion; 4. a second bending portion; 5. a ring electrode; 6. a pull rod; 7. organization.

Detailed Description

The present application will be described in detail below. While specific embodiments of the application are shown, it should be understood that the application may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

It should be noted that certain terms are used throughout the description and claims to refer to particular components. Those of skill in the art will understand that a person may refer to the same component by different names. The specification and claims do not identify differences in terms of components, but rather differences in terms of the functionality of the components. As referred to throughout the specification and claims, the terms "include" or "comprising" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. The description hereinafter sets forth a preferred embodiment for practicing the application, but is not intended to limit the scope of the application, as the description proceeds with reference to the general principles of the description. The scope of the application is defined by the appended claims.

In the interventional medical field, the end closest to the operator is defined as the "proximal end" and the end distal from the operator is defined as the "distal end". For an elongated article, a direction parallel to its length extension is defined as "axial"; for an object with a circular cross-section, the direction surrounding its axis is defined as "circumferential". For a cylindrical object, the direction of extension is defined as "axial", and the radial direction of the circular cross-section is defined as "radial".

Referring to fig. 1, the present application provides an electrophysiology mapping catheter. The pipe body 1 and the electrode branch 2 arranged at the far end of the pipe body 1 are included, the electrode branch 2 is arranged in a plurality along the circumferential direction of the pipe body 1, and the electrode branch 2 extends from the connection position with the pipe body 1 towards the direction far away from the pipe body 1.

Referring to fig. 1, the electrophysiological mapping catheter in the present application is used for mapping a human tissue 7, and in mapping the human tissue 7 by using the electrophysiological catheter, a sheath tube and a three-dimensional modeling system are also used at the same time, wherein the sheath tube extends into the human body to provide an access channel for the electrophysiological mapping catheter, and the three-dimensional modeling system is used for processing mapping signals of the human tissue 7 by using the electrophysiological mapping catheter, so as to construct a three-dimensional model of the human tissue 7, and is used for accurately positioning abnormal focus points of the tissue 7.

Referring to fig. 1, the electrode branch 2 can capture weak current generated by the human tissue 7 during the activity, the electrode branch 2 transmits captured microcurrent signals to a three-dimensional modeling system, and the three-dimensional modeling system constructs an electrophysiological three-dimensional model of the human tissue 7 according to signals marked by the electrode branch 2, so that the electrode branch 2 is used for accurately positioning the focus position of the human tissue 7 to facilitate the subsequent ablation treatment.

Referring to fig. 2 and 3, the plurality of electrode branches 2 are dispersed towards the direction away from the tube body 1, so that the electrode branches 2 can extend to the position away from the tube body 1, and further the electrode branches 2 can map the human tissue 7 in a larger range, and further the mapping speed of the electrode branches 2 to the human body is improved.

Referring to fig. 2 and 3, the electrode branches 2 are provided in plurality, the plurality of electrode branches 2 are uniformly arranged along the circumferential direction of the pipe body 1, and the plurality of electrode branches are independent from each other. Therefore, the electrode branches 2 can perform mapping on the peripheral positions of the distal end of the tube body 1, and when the human tissue 7 is mapped, the movement of the electrode branches 2 can be realized by moving the tube body 1, so that the mapping of the electrode branches 2 on the human body is facilitated.

Referring to fig. 2 and 3, the electrode branch 2 includes a curved first curved portion 3, and the first curved portion 3 is located at a position where the electrode branch 2 is farthest from the catheter.

Referring to fig. 2 and 3, when the electrode branches 2 are deployed along the tube body 1 in a direction away from the tube body 1, the first bending portion 3 is transported to a position farthest in the deployment direction.

Referring to fig. 1, when the electrode branch 2 marks the human tissue 7, the electrode branch 2 will abut against the human tissue 7, and the distal end of the electrode branch 2 is in the same plane as the proximal end of the electrode branch 2 or in a convex state compared with the proximal end of the electrode branch 2 in order to achieve perfect abutment with the tissue 7. When the electrode branches 2 are in abutment with the tissue 7, the distal ends of the electrode branches 2 will first abut against the tissue 7, and then the proximal ends of the electrode branches 2 will overlap the tissue 7.

Referring to fig. 1, when the distal end of the electrode branch 2 is abutted against the tissue 7, only the distal end of the electrode branch 2 is abutted against the tissue 7, and the contact area between the electrode branch 2 and the tissue 7 is small, so that the pressure of the distal end of the electrode branch 2 on the tissue 7 is large, and the electrode branch 2 is easy to crush and damage the tissue 7 at the distal end.

Referring to fig. 1, in the present application, the first bending part 3 is disposed at the most distal end of the electrode branch 2, and thus, the first bending part 3 is brought into contact with the tissue 7 when the electrode branch 2 is brought into contact with the tissue 7. The first bend 3, which assumes a curved shape, conceals the sharp end, thus greatly reducing the penetration damage of the electrode branches 2 to the tissue 7. Meanwhile, the first bending part 3 has larger contact area when contacting the tissue 7, so that the pressure of the electrode branch 2 to the human tissue 7 is reduced, and the possibility of damaging the tissue 7 by the electrode branch 2 is further reduced. Further reducing the probability of premature beat.

It should be noted that, when the electrode branch 2 is used to mark the tissue 7, since the electrode branch 2 has a larger size in the radial direction of the tube body 1, and the human tissue 7 is mostly in a structure with a wide outside and a narrow inside, such as a left atrial pulmonary vein junction, when the electrode branch 2 marks the tissue 7, due to the structural characteristics of the human tissue 7, the distal end of the electrode branch 2 will contact the tissue 7 first, and then along with the continuous pushing of the tube body 1, the electrode branch 2 will undergo corresponding elastic deformation to be abutted against the tissue 7. In order to reduce the possibility of the electrode branch 2 from stabbing the tissue 7, the first bending portion 3 is positioned at the most distal position, so that the first bending portion 3 is in contact with the human tissue 7 in advance, and the occurrence of the electrode branch 2 from stabbing the tissue 7 is reduced. Further reducing the probability of premature beat.

The tip of the electrode branch 2 is located at a distal-most position compared to conventional electrophysiology mapping catheters in the art. The distal tip location of conventional electrophysiology mapping catheters can easily stab human tissue 7 when applied to human tissue 7. In the present application, the first bending portion 3 conceals the tip position of the tip due to the arc structure, thereby greatly reducing the possibility of stabbing the tissue 7.

With reference to fig. 2 and 3, a ring electrode 5 is provided on the electrode branch 2, which can be used for mapping.

The ring electrode 5 is sleeved on the electrode branch 2, the ring electrode 5 can capture micro-current generated by human tissue 7 due to electrophysiological characteristics, the ring electrode 5 then transmits the detected micro-current signals to the three-dimensional modeling system, the three-dimensional modeling system then builds a model of the three-dimensional structure of the tissue 7 by using the electrical signals detected by the ring electrode on the electrode branch 2, and a three-dimensional detection model of the human tissue 7 with electrophysiological characteristics is constructed according to the micro-current signals detected by the ring electrode 5. The user can then determine the target location of the body tissue 7 to be ablated based on the electrophysiological three-dimensional model of the body tissue 7.

Referring to fig. 2 and 3, the first bending part 3 is bent in a plane near the vertical pipe body 1.

The first bending part 3 is located at a position near the middle of the electrode branch 2, so that the branch electrode extends in a common plane with the rest of the electrode branch 2 after bending at the first bending part 3 position. So that the electrode branches 2 at both end positions of the first bending part 3 can be commonly mapped. And further enables the electrode branches 2 to be fully utilized to the greatest extent.

In addition, a plurality of mutually independent electrode branches 2 are all arranged along the circumference of the tube body 1, and when the electrode branches 2 mark the tissue 7, the electrode branches can be unfolded into a plane perpendicular to the tube body 1 and then are attached to the tissue 7 for marking. The first bending section 3 thus bends in a plane of the electrode branches 2 when they are in contact with the tissue 7, i.e. a plane perpendicular to the tube body 1, when bending. Therefore, when the first bending part 3 is abutted against the tissue 7, the bending shape increases the contact length of the electrode branch 2 and the tissue 7, so that the contact area of the electrode branch 2 and the tissue 7 is increased, and the compression injury of the electrode branch 2 to the tissue 7 is reduced. On the other hand, the first bending portion 3 is bent perpendicularly to the tube body 1, so that the electrode branches 2 can be used in the longitudinal direction to a greater extent when the electrode branches 2 are abutted against the tissue 7.

Referring to fig. 2 and 3, both ends of the electrode branch 2 extend from the first bent portion 3 toward the direction approaching the pipe body 1.

Referring to fig. 2 and 3, in order to locate the first bending portion 3 at the position where the branch electrode is farthest from the tube body 1, the electrode branches 2 are extended toward the tube body 1 on both sides of the first bending portion 3, so that the first bending portion 3 is first brought into contact with the tissue 7 when the electrode branches 2 are abutted against the tissue 7.

Referring to fig. 3, in one embodiment, the end of the electrode branch 2 remote from the tube body 1 is a free end. The free ends of the electrode branches 2 extend towards the direction approaching the pipe body 1; the electrode branches 2 are annular.

Referring to fig. 3, by arranging the electrode branches 2 in a ring shape, the ends of the electrode branches 2 are further hidden, so as to reduce the possibility of the ends of the electrode branches 2 causing stabbing damage to the human tissue 7.

Referring to fig. 3, one end of the electrode branch 2 is fixedly connected with the pipe body 1, the other end of the electrode branch 2 is a free end, and at this time, the free end of the electrode branch 2 extends toward a direction approaching the pipe body 1 after passing through the first bending portion 3, so that the end of the free end of the electrode branch 2 is hidden at a position approaching the pipe body 1. Thus, when the electrode branch 2 is abutted against the tissue 7, the free end of the electrode branch 2 is located close to the tube body 1, so that the first bending part 3 is firstly contacted with the tissue 7, and the possibility of stabbing the tissue 7 by the free end of the electrode branch 2 is reduced.

Referring to fig. 1 and 2, in another embodiment, the first bending portion 3 is located at a position of the electrode branch 2 farthest from the pipe body 1, both ends of the electrode branch 2 extend toward the pipe body 1, and both ends of the electrode branch 2 are fixedly connected to the pipe body 1, so that the electrode branch 2 is in a ring shape. When the electrode branch 2 is abutted against the tissue 7, the first bending part 3 is contacted with the tissue 7, and as the two ends of the electrode branch 2 are fixedly connected to the pipe body 1, the possibility of stabbing the tissue 7 by the end head of the electrode branch 2 is reduced. Further reducing the probability of premature beat.

Referring to fig. 2 and 3, in another aspect of the present application, the electrode branches 2 are arranged in a long shape, the electrode branches 2 are bent near the middle to form the first bending portion 3, and both ends of the electrode branches 2 are arranged near the pipe body 1, so that the electrode branches 2 are in a ring structure, and further, a larger mapping range of each branch electrode can be realized, and the mapping range of each electrode branch 2 is twice as large as that of the conventional electrode branches 2. The mapping range of the electrode branches 2 is greatly improved, and in addition, the number of the electrode branches 2 arranged on the pipe body 1 is reduced, so that the manufacturing cost of the electrode branches 2 is reduced.

Referring to fig. 2 and 3, the electrode branch 2 includes a second curved portion 4, the second curved portion 4 being located at a position of the electrode branch 2 near the tube body 1, the second curved portion 4 being curved toward a direction away from the central axis of the catheter.

Referring to fig. 2 and 3, the second bending portion 4 is located at the root of the electrode branch 2, and is used for adjusting the direction of the electrode branch 2, so that when the electrode branch 2 is marked in the human body, the second bending portion 4 can cause the distal end position of the electrode branch 2 to bend towards the direction away from the tube body 1, so that the electrode branch 2 can map a larger range of human tissue 7, and the mapping efficiency is improved.

Referring to fig. 1 and 2, in a specific embodiment, the tube body 1 is of a hollow structure, a pull rod 6 is slidably connected inside the tube body 1, and one end of the electrode branch 2 is fixedly connected to the distal end of the pull rod 6; one end of the electrode branch 2 far away from the pull rod 6 is fixedly connected to the pipe body 1.

Referring to fig. 1 and 2, both ends of the electrode branches 2 are fixed to the tie rod 6 and the pipe body 1, respectively, so that when the tie rod 6 reciprocates inside the pipe body 1, both ends of the electrode branches 2 come close to or separate from each other as the tie rod 6 moves.

Referring to fig. 1 and 2, when the pull rod 6 is controlled to move toward the distal end direction of the tube body 1, both ends of the electrode branch 2 are simultaneously driven to move away from each other, the electrode branch 2 is subjected to a stretching force, so that the first bending part 3 and the second bending part 4 of the electrode branch 2 and the electrode branch 2 body are stretched into a straight line, at this time, the electrode branch 2 is stretched to be arranged along the axial direction of the tube body 1 under the action of the pull rod 6, so that the electrode branch 2 is in a contracted shape and is contracted between the tube body 1 and the pull rod 6, and the size of the electrode branch 2 in the radial direction of the tube body 1 is contracted to be very small, so that the electrode branch 2 is conveniently conveyed into the human body.

Referring to fig. 1 and 2, after the electrode branch 2 is delivered into the human body, the pull rod 6 can be controlled to move towards the proximal end so that the two ends of the electrode branch 2 are close to each other, and under the elastic action of the first bending part 3 and the second bending part 4, the electrode branch 2 can bend along with the movement of the pull rod 6 so that the electrode branch 2 is bent towards a direction away from the pipe body 1. And depending on the distance the pull rod 6 moves, the distance between the electrode branch 2 and the pipe body 1, i.e. the extent of deployment of the electrode branch 2, can also be controlled. Furthermore, the dimension of the electrode branches 2 in the radial direction of the tube body 1 can be controlled when the tissue 7 is marked. Until the pull rod 6 is pulled proximally to a limit position, the dimension of the electrode branches 2 in the radial direction is expanded to a maximum, while also allowing both ends of the electrode branches 2 to lie in a plane close to the vertical to the tube body 1. The control of the pipe body 1 to the electrode branch 2 is more convenient. The electrode branches 2 can be accurately conveyed to a target position for mapping under the control of the pipe body 1.

The electrode branches 2 are made of high-molecular polyurethane, and preferably, a supporting framework is arranged in the pipe wall of the electrode branches 2; further preferably, the supporting framework is made of memory qualitative materials, and further preferably, the supporting framework is made of memory metal.

The electrode branches 2 are used for supporting the ring electrodes 5, and meanwhile, the electrode branches 2 prepared from high-molecular polyurethane can have a good insulating effect on the ring electrodes 5, so that the influence on the mapping accuracy between the ring electrodes 5 is reduced.

The supporting framework (not shown in the figure) is used for supporting the electrode branches 2, and the supporting framework is arranged inside the electrode branches 2 made of high polymer polyurethane. At the same time, the support framework has certain elasticity and memory, so that the electrode branches 2 can be unfolded according to the set shape after being conveyed into the human body. And further mapping the human tissue 7.

The memory metal is used as a supporting framework and is installed inside the electrode branch 2, when the electrode branch 2 is conveyed into the human body, the shape of the electrode branch 2 is changed even if the electrode branch 2 is subjected to the action of external force, and under the action of the memory metal, the electrode branch 2 can be restored to a preset state by virtue of the memory characteristic after being conveyed into the human body.

Referring to fig. 1 and 2, when the distal end of the pull rod 6 moves near the distal end of the tube body 1, the electrode branches 2 are bent in a ring shape in the radial direction of the tube body 1.

Referring to fig. 1 and 2, the plane in which the loop of the electrode branches 2 is formed tends to be a plane perpendicular to the pull rod 6.

Referring to fig. 1 and 2, when the pull rod 6 is pulled toward the proximal end, since the first bending portion 3 is bent in a plane perpendicular to the tube body 1, when the electrode branches 2 are bent near both ends, the electrode branches 2 tend to rotate in a direction perpendicular to the tube body 1 by the first bending portion 3, so that the projection of the electrode branches 2 in the cross section of the tube body 1 is annular. When the pull rod 6 pulls the two ends of the electrode branch 2 to the extreme positions, the electrode branch 2 is in a ring shape which is connected end to end or similar and is spread along a plane perpendicular to the pipe body 1. Therefore, in the process of pulling the pull rod 6 to the proximal end, the two ends of the electrode branch 2 are gradually close, and the electrode branch 2 body at the first bending part 3 is bent and simultaneously has certain rotation deformation, so that an inclined shape of an included angle exists between the electrode branch 2 body and the axis of the pipe body 1, and the included angle between the electrode branch 2 and the axis of the pipe body 1 is also increased along with the gradual closing of the two ends of the electrode branch 2 until the electrode branch 2 and the axis of the pipe body 1 are in a nearly vertical position; i.e. the electrode branches 2 will tend to lie in a plane perpendicular to the tie rod 6 when bent. The electrode branches 2 are positioned on two sides of the first bending part 3 and are positioned on adjacent planes, so that the influence of the reduction of the mapping efficiency caused by the time difference between the electrode branches 2 and the tissue 7 due to the overlarge difference between the electrode branches 2 on the axis of the tube body 1 during the mapping is avoided.

In summary, the present application provides an electrophysiology mapping catheter, in one embodiment, one end of the electrode branch 2 is fixed on the tube body 1, and the other end of the electrode branch 2 is fixed on the pull rod 6. When the electrophysiology catheter is in use, the pull rod 6 is pulled to the far end by controlling the pull rod 6, so that the two ends of the electrode branch 2 are respectively stretched by the pull rod 6 and the tube body 1, the electrode branch 2 is in a straightened state, the electrode branch 2 is attached to the pull rod 6, and the electrode branch 2 is in a contracted state. Then the electrode branch 2, the pull rod 6 and the tube body 1 are conveyed to a target position in the human body through a sheath, then the pull rod 6 is pulled towards the proximal end, the electrode branch 2 is bent, the two ends of the electrode branch 2 are positioned at the close limit positions, the electrode branch 2 is in a ring-shaped structure under the action of the first bending part 3, and then the tube body 1 is controlled to enable the ring electrode 5 on the electrode branch 2 to be in contact with the tissue 7 for mapping. When the mapping is completed, the pull rod 6 is pushed to move towards the distal end again, so that the electrode branch 2 is stretched and contracted, and then the inside of the human body is withdrawn from the sheath.

In another embodiment, one end of the electrode branch 2 is fixed on the pipe body 1, and the other end of the electrode branch 2 is a free end. When the electrode branch 2 and the tube body 1 are conveyed into a human body, the electrode branch 2 is stretched towards the proximal end and is attached to the tube body 1, then the tube body is conveyed into a sheath tube, the electrode branch 2 is conveyed to a target position in the human body through the sheath tube, then the tube body 1 is pushed, the branch electrode is pushed out of the sheath tube, the electrode branch 2 is restored to be annular under the elastic action, and then the tissue 7 is mapped. When the mapping of the tissue 7 is completed, the tube body 1 is directly drawn proximally, and the electrode branches 2 are contracted under the action of the sheath tube and then discharged outside the body along the sheath tube.

The present embodiment is only for explanation of the present application and is not to be construed as limiting the present application, and modifications to the present embodiment, which may not creatively contribute to the present application as required by those skilled in the art after reading the present specification, are all protected by patent laws within the scope of claims of the present application.

Claims

1. An electrophysiology mapping catheter comprises a catheter body and electrode branches arranged at the distal end of the catheter body, wherein a plurality of electrode branches are arranged along the circumference of the catheter body, and the electrode branches extend from a position connected with the catheter body in a direction away from the catheter body;

2. The catheter of claim 1, the first bend being curved in a plane proximate to a vertical tube body.

3. The catheter of claim 1 or 2, wherein the electrode branch includes a second curved portion at a position of the electrode branch near the tube body, the second curved portion being curved toward a direction away from the central axis of the catheter.

4. A catheter according to any one of claims 1 to 3, wherein both ends of the electrode branch extend from the first curved portion in a direction approaching the tubular body.

5. The catheter according to any one of claims 1-4, wherein the catheter body is of a hollow structure, a pull rod is slidably connected inside the catheter body, and one end of the electrode branch is fixedly connected to the distal end of the pull rod; one end of the electrode branch, which is far away from the pull rod, is fixedly connected on the pipe body.

6. The catheter of claim 5, wherein the electrode branches bend annularly in the radial direction of the shaft as the distal end of the pull rod moves closer to the distal end of the shaft.

7. The catheter of claim 5, wherein the loop formed by the electrode branches is oriented in a plane perpendicular to the pull rod.

8. The catheter of any one of claims 1-4, wherein the end of the electrode branch distal from the shaft is a free end.

9. The catheter of claim 8, wherein the free ends of the electrode branches extend in a direction toward the proximal shaft; the electrode branches are annular.

10. The catheter according to any one of claims 1 to 9, wherein the electrode branches are made of polymer polyurethane, and preferably, a supporting framework is arranged inside the wall of the electrode branches; further preferably, the supporting framework is made of memory qualitative materials, and further preferably, the supporting framework is made of memory metal.

11. Catheter according to any of claims 1-10, on the electrode branches ring electrodes are provided which can be used for mapping.