A mapping catheter

Abstract

The utility model belongs to the technical field of medical apparatus and instruments, disclose a kind of mapping catheter, including outer catheter, center axis, multiple distal branches and reference electrode center axis's proximal end is set in the outer catheter, distal end stretches out the distal end of the outer catheter;Multiple distal branches are set in the distal end of the outer catheter and are arranged around the center axis along the circumference, and the distal branch includes first branch section and second branch section, the proximal end of the first branch section is connected with the distal end of the outer catheter, the distal end of the first branch section is connected with the proximal end of the second branch section, and the distal end of multiple first branch sections is inclined to the center axis of the outer catheter and is formed into first cage structure;Reference electrode is set outside the center axis, and located in the first cage structure.The utility model not only can ensure that reference electrode effectively extracts far field signal, and can reduce the risk that reference electrode contacts tissue.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a mapping catheter. Background Technology

[0002] Atrial fibrillation (AF) is one of the most common arrhythmias in clinical practice and a major challenge facing the global cardiovascular field in the 21st century. Approximately 10 million people in China suffer from this disease, severely impacting their quality of life. Catheter ablation is currently one of the effective treatments for AF, and mapping catheters are crucial tools for doctors to trace the source of the disease and develop ablation plans.

[0003] Mapping catheters are interventional medical devices used to collect intracardiac biological signals and are widely used in cardiac electrophysiological examinations and radiofrequency ablation for arrhythmias. The standard surgical procedure for mapping catheters involves placing the catheter via puncture of the femoral vein or superior vena cava, and then advancing it to the target site for signal extraction. To achieve efficient and rapid mapping, various high-density mapping catheters have been developed. These catheters typically have a reference electrode and multiple branches with multiple loop electrodes at the distal end, and a saline infusion tubing is placed within the catheter body.

[0004] In existing technologies, to avoid contact between the reference electrode and tissue, some methods place the reference electrode inside the saline irrigation cannula. However, during surgery, the saline irrigation cannula needs to continuously infuse saline, which may prevent blood from entering the cannula, making it difficult for the reference electrode to effectively extract far-field signals. If the reference electrode is placed outside the saline irrigation cannula, there is a risk of contact with tissue. Therefore, how to ensure that the reference electrode can effectively extract far-field signals while reducing the risk of tissue contact is a pressing problem that needs to be solved. Utility Model Content

[0005] The purpose of this application is to provide a mapping catheter that not only ensures that the reference electrode can effectively extract far-field signals, but also reduces the risk of the reference electrode coming into contact with tissue.

[0006] The technical solution provided in this application is as follows:

[0007] A mapping catheter, comprising:

[0008] External catheter;

[0009] The central axis is located proximally within the external conduit and extends distally from the distal end of the external conduit.

[0010] Multiple distal branches are arranged circumferentially at the distal end of the external catheter and around the central axis. Each distal branch includes a first branch segment and a second branch segment. The proximal end of the first branch segment is connected to the distal end of the external catheter, and the distal end of the first branch segment is connected to the proximal end of the second branch segment. The distal ends of the multiple first branch segments are all inclined toward the central axis of the external catheter to form a first cage-like structure.

[0011] The reference electrode is disposed outside the central axis and located within the first cage structure.

[0012] In some embodiments, the first cage structure is truncated conical in shape, and the proximal cross-sectional area of ​​the first cage structure is larger than the distal cross-sectional area of ​​the first cage structure.

[0013] In some embodiments, the cross-sectional area of ​​the first cage structure gradually increases and then gradually decreases from the proximal end to the distal end.

[0014] In some implementations, the stiffness of the first branch segment is greater than the stiffness of the second branch segment.

[0015] In some implementations, the cross-sectional area of ​​the first branch segment is greater than the cross-sectional area of ​​the second branch segment.

[0016] In some embodiments, when the central axis is an infusion catheter, the axial distance from the reference electrode to the distal end of the infusion catheter is greater than a preset value.

[0017] In some embodiments, the axial distance from the reference electrode to the distal end of the first cage structure is less than the axial distance from the distal end of the first cage structure to the distal end of the external conduit.

[0018] In some embodiments, a plurality of ring electrodes are also included, with one or more of the ring electrodes provided on each of the second branch segments.

[0019] In some embodiments, multiple second branch segments are arranged to form a second cage-like structure, which is cylindrical, frustum-shaped, or trumpet-shaped.

[0020] In some embodiments, multiple second branch segments are arranged to form a second cage-like structure;

[0021] The cross-sectional area of ​​the second cage structure increases from the proximal end to the distal end and then remains constant; or the cross-sectional area of ​​the second cage structure increases from the proximal end to the distal end and then decreases; or the cross-sectional area of ​​the second cage structure decreases from the proximal end to the distal end and then increases.

[0022] The technical advantages of this application are as follows:

[0023] (1) The distal ends of multiple first branch segments are inclined towards the central axis of the external catheter. During the outward deformation of the second branch segment to adhere to the tissue, the distal ends of the first branch segments are not easily opened outward, that is, the distal ends of the first cage-like structure are not easily expanded outward, so that the first cage-like structure can maintain its cage-like structure to better cover the reference electrode, thereby protecting the reference electrode from contacting the tissue. In addition, in this embodiment, the reference electrode is set outside the central axis. When saline is perfused inside the central axis, it will not affect the reference electrode's contact with blood, so that the reference electrode can effectively extract the reference signal.

[0024] (2) The stiffness of the first branch segment is greater than that of the second branch segment. The first branch segment has better support and resistance to deformation than the second branch segment, enabling it to maintain a stable cage-like structure and better protect the reference electrode from contact with the tissue, thereby avoiding baseline drift caused by the reference electrode contacting the tissue. In addition, the second branch segment has lower stiffness and better flexibility, allowing it to better adhere to the tissue, thus enabling the ring electrode on the second branch segment to make full contact with the tissue to obtain high-quality electrophysiological signals.

[0025] (3) When the central axis is the perfusion conduit, the axial distance from the reference electrode to the far end of the perfusion conduit is greater than the preset value, which can avoid the saline solution perfused into the perfusion conduit affecting the accuracy of the electrical signal collected by the reference electrode.

[0026] (4) The axial distance from the reference electrode to the distal end of the first cage structure is designed to be smaller than the axial distance from the distal end of the first cage structure to the distal end of the external catheter. Deformation of the distal end of the first cage structure or contact with the tissue will not be transmitted to the reference electrode, thereby ensuring that the reference electrode is always isolated from the tissue and ensuring the accuracy and stability of the potential reference signal obtained by the reference electrode. Attached Figure Description

[0027] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0028] Figure 1 This is a schematic diagram of the structure of a mapping catheter provided in one embodiment of this application from a certain perspective;

[0029] Figure 2 This is a schematic diagram of the structure of a mapping catheter provided in one embodiment of this application from another perspective;

[0030] Figure 3 yes Figure 2 A partial enlarged view of the mapping catheter shown;

[0031] Figure 4 This is a schematic diagram of the structure of a distal branch provided in an embodiment of this application;

[0032] Figure 5 yes Figure 4 A schematic diagram of the cage-like structure formed by the distal branch shown.

[0033] Figure 6 This is a schematic diagram of the structure of a distal branch provided in another embodiment of this application;

[0034] Figure 7 This is a schematic diagram of the structure of a spherical high-density mapping catheter provided in one embodiment of this application;

[0035] Figure 8 This is a schematic diagram of the structure of a flat density mapping catheter provided in one embodiment of this application;

[0036] Figure 9 This is a schematic diagram of the structure of a remote branch provided in another embodiment of this application.

[0037] Explanation of icon numbers:

[0038] 100, external catheter; 200, central axis; 300, distal branch; 310, first branch segment; 320, second branch segment; 410, reference electrode; 420, ring electrode; 500, first cage structure; 600, second cage structure; 710, first part; 720, second part. Detailed Implementation

[0039] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application can also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0040] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the specific implementation methods of this application will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without creative effort.

[0041] To keep the drawings concise, each drawing only schematically shows the parts relevant to this application, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of the components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0042] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0043] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; or they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0044] In the embodiments shown in the accompanying drawings, the directional indications (such as up, down, left, right, front, and back) are relative rather than absolute when describing the structure and movement of the various components, and are not intended to limit the direction of the product during actual use.

[0045] Furthermore, in the description of this application, ordinal numbers, such as "first" and "second," are used only to distinguish related objects and should not be construed as indicating or implying the relative importance or order between related objects.

[0046] In this application, the terms "proximal" and "distal" refer to the relative orientation, position, and direction of elements or movements relative to each other from the perspective of a physician using the medical device. Although "proximal" and "distal" are not restrictive, "proximal" generally refers to the end of the medical device that is closer to the physician during normal operation, while "distal" generally refers to the end that first enters the patient's body.

[0047] like Figures 1 to 5 As shown, in one or more embodiments, this disclosure provides a mapping catheter, including an outer catheter 100, a central axis 200, a plurality of distal branches 300, and a reference electrode 410; the proximal end of the central axis 200 is disposed within the outer catheter 100, and the distal end of the central axis 200 extends out of the distal end face of the outer catheter 100; the plurality of distal branches 300 are circumferentially disposed at the distal end of the outer catheter 100 and surrounding the central axis 200, and the distal branches 300 include a first branch segment 310 and a second branch segment 320, the proximal end of the first branch segment 310 is connected to the distal end of the outer catheter 100, and the distal end of the first branch segment 310 is connected to the proximal end of the second branch segment 320, and the distal ends of the plurality of first branch segments 310 are all inclined toward the central axis of the outer catheter 100 to form a first cage structure 500; the plurality of second branch segments 320 surround to form a second cage structure 600; the reference electrode 410 is disposed on the outer side wall of the central axis 200 and located within the first cage structure 500.

[0048] The external catheter 100 extends from its proximal end to its distal end. The proximal end of the external catheter 100 is connected to a control handle, while the distal end is typically a bendable section. This bendable section is designed with low rigidity to facilitate flexible unidirectional or bidirectional bending operations under the control handle at the proximal end of the external catheter 100. This facilitates the delivery of the mapping catheter to the target location for signal extraction. The bending operation of the external catheter 100 is existing technology and will not be described in detail here.

[0049] The central shaft 200 passes through the outer catheter 100. In this embodiment, the central shaft 200 can be an infusion catheter for infusing saline solution. The diameter of the infusion catheter is smaller than the inner diameter of the outer catheter 100, and the infusion catheter can pass through the lumen of the outer catheter 100. The proximal inlet of the infusion catheter is located at the control handle at the proximal end of the outer catheter 100, for connecting an infusion device. The distal outlet of the infusion catheter extends a certain distance from the distal end of the outer catheter 100 to perform infusion operations, such as infusing flushing fluid (e.g., saline solution) from the proximal end of the mapping catheter to the target site in the patient's body. In other embodiments, infusion can also be performed in other ways, and the central shaft 200 can be used as a lever for operating the second cage structure 600, or for operations such as delivering instruments or administering medication.

[0050] Multiple distal branches 300 are respectively disposed at the distal end of the external conduit 100 and arranged around the central axis 200. The proximal ends of the multiple distal branches 300 are uniformly fixed to the inner wall of the distal end of the external conduit 100 in a circumferential direction; or the proximal ends of the multiple distal branches 300 are uniformly fixed to the outer wall of the distal end of the external conduit 100 in a circumferential direction, and a sleeve is provided outside the proximal end of the distal branches 300 for fixation. The distal branches 300 can be made of a superelastic shape memory material (e.g., nickel-titanium alloy). Under constrained conditions, the distal branches 300 can be retracted into the delivery device and automatically unfolded into a preset shape after release. For example, the proximal end (first branch segment 310) of the distal branch 300 unfolds into a first cage structure 500, and the distal end (second branch segment 320) of the distal branch 300 unfolds into a second cage structure 600.

[0051] The distal branch 300 includes a first branch segment 310 and a second branch segment 320. The proximal end of the first branch segment 310 is connected to the distal end of the external catheter 100 and is evenly distributed along the circumference of the external catheter 100. The distal end of the first branch segment 310 is connected to the proximal end of the second branch segment 320. In this embodiment, no ring electrode for acquiring electrical signals is provided on each first branch segment 310. Each second branch segment 320 is provided with one or more ring electrodes 420 for acquiring electrical signals. The ring electrodes 420 are insulated from each other by an insulating sleeve fitted on the outer wall of the second branch segment 320. During operation, the ring electrodes 420 on the second branch segment 320 will contact the patient's tissue to acquire the potential of different parts of the heart.

[0052] When the ring electrode 420 acquires potentials, the second branch segment 320 abuts against the tissue surface, causing one or more second branch segments 320 to flatten approximately along the tissue surface. In other words, one or more second branch segments 320 expand and deform outwards, becoming approximately parallel to the tissue surface, thus allowing the ring electrode 420 to directly contact the tissue surface and acquire potentials from the tissue. The reference electrode 410 is positioned outside the central axis 200 and within the first cage-like structure 500 formed by the multiple first branch segments 310. The reference electrode 410 does not contact the patient's tissue but rather the blood to acquire a reference potential. An external processor processes the reference potential acquired by the reference electrode 410 and the potentials acquired by the ring electrode 420 at different locations. By comparing the potential differences between the ring electrode 420 and the reference electrode 410 at different locations, areas of abnormal electrical activity within the heart can be precisely located, providing crucial information for subsequent catheter ablation therapy.

[0053] In this embodiment, when the mapping catheter is working, the distal end of the second branch segment 320 first adheres to the tissue. As the mapping catheter continues to be pushed towards the tissue surface, the second branch segment 320 expands and deforms outward under the action of the tissue, so as to achieve complete contact between the second branch segment 320 and the tissue. Since the distal ends of the multiple first branch segments 310 are all inclined towards the central axis of the catheter, the distal ends of the first branch segments 310 are not easy to expand outward during the outward expansion of the second branch segment 320. That is, the distal end of the first cage structure 500 is not easy to expand outward, so that the first cage structure 500 can maintain its cage structure to better cover the reference electrode 410, thereby protecting the reference electrode 410 from contacting the tissue. In addition, in this embodiment, the reference electrode 410 is disposed outside the central axis 200. When saline is injected into the central axis 200, it will not affect the contact of the reference electrode 410 with blood, so that the reference electrode 410 can effectively extract the reference signal.

[0054] In some embodiments, the first cage structure 500 is truncated conical in shape, and the proximal cross-sectional area of ​​the first cage structure 500 is larger than the distal cross-sectional area of ​​the first cage structure 500. For example... Figure 4As shown, the proximal interface of the first cage-like structure 500 is A1, and the distal interface is A2. The cross-sectional area of ​​the proximal interface A1 is larger than that of the distal interface A2. The first cage-like structure 500 is defined by interfaces A1 and A2, and the reference electrode 410 is disposed within the space defined by interfaces A1 and A2. The proximal ends of multiple first branch segments 310 are located on the cross-sectional contour line of interface A1, and the distal ends of multiple first branch segments 310 are located on the cross-sectional contour line of interface A2. When the second branch segment 320 deforms and unfolds outward, the distal end of the truncated conical first cage-like structure 500 in this embodiment is less likely to unfold outward compared to cylindrical or flared structures, so that the first cage-like structure 500 can better protect the reference electrode 410 from contacting tissue and improve the quality of the electrical signal acquired by the reference electrode 410.

[0055] In some embodiments, such as Figure 6 As shown, the cross-sectional area of ​​the first cage-like structure 500 formed by multiple first branch segments 310 gradually increases and then gradually decreases from the proximal end to the distal end. The first cage-like structure 500 can form an approximately lantern-shaped structure or an approximately spherical structure. The proximal interface of the first cage-like structure 500 is A3, the middle section is A4, and the distal interface is A5. The cross-sectional area of ​​the middle section A4 is greater than the cross-sectional areas of the proximal interface A3 and the distal interface A5. The cross-sectional area of ​​the proximal interface A3 can be greater than, equal to, or less than the cross-sectional area of ​​the distal interface A5. The proximal ends of the first branch segments 310 are located on the cross-sectional outline of the proximal interface A3, and the distal ends of the first branch segments 310 are located on the cross-sectional outline of the distal interface A5.

[0056] In this embodiment, the distal end of the first cage structure 500 is also inclined toward the central axis of the external catheter 100, so that when the second branch segment 320 deforms outward to fit against the tissue, the distal end of the first cage structure 500 is not easy to unfold outward and expose the reference electrode 410. This allows the first cage structure 500 to better protect the reference electrode 410 from contacting the tissue and improve the electrical signal quality of the reference electrode 410.

[0057] like Figure 4 and Figure 5 As shown, the second cage-like structure 600 formed by multiple second branch segments 320 is frustum-shaped or trumpet-shaped, such as... Figure 4As shown, the interface between the first cage structure 500 and the second cage structure 600 is interface A2. The proximal interface of the second cage structure 600 is A2, and the distal interface is A6. The second cage structure 600 is defined by interfaces A2 and A6. The proximal ends of multiple second branch segments 320 are located on the cross-sectional outline of interface A2, and the distal ends of multiple second branch segments 320 are located on the cross-sectional outline of interface A6. The cross-sectional area of ​​interface A2 is smaller than that of interface A6, making the second cage structure 600 frustum-shaped or trumpet-shaped.

[0058] In other embodiments, the second cage structure 600 may also be cylindrical, that is, the cross-sectional area of ​​the proximal end of the second cage structure 600 is equal to the cross-sectional area of ​​the distal end; or the cross-sectional area of ​​the second cage structure 600 increases and then decreases from the proximal end to the distal end, forming an approximately spherical or lantern shape; or the cross-sectional area of ​​the second cage structure 600 increases and then remains constant from the proximal end to the distal end; or the cross-sectional area of ​​the second cage structure 600 decreases and then increases from the proximal end to the distal end.

[0059] For example, Figure 7 This is a spherical high-density mapping catheter. The central axis 200 serves as an operating rod for manipulating the second cage-like structure 600. A reference electrode 410 is positioned proximally on the operating rod and at a certain distance from the distal end of the outer catheter 100. The proximal side of the distal branch 300 is divided into a first part 710 and a second part 720 based on their cross-sectional areas. Interfaces A7 and A8 define the first part 710, with the cross-sectional area of ​​interface A7 being larger than that of interface A8. Interfaces A8 and A9 define the second part 720, with the cross-sectional area of ​​interface A8 being smaller than that of A9. The first part 710 is a first cage-like structure 500, and the second part 720 is a portion of the second cage-like structure 600. The cross-sectional area of ​​the first cage-like structure 500 gradually decreases from proximally to distally; the cross-sectional area of ​​the second cage-like structure 600 first increases and then decreases from proximally to distally, forming an approximately spherical structure.

[0060] For example, Figure 8This is a flat density mapping catheter with a central axis 200 that is a saline infusion catheter. A reference electrode 410 is disposed on the outer wall of the infusion catheter. The proximal side of the distal branch is divided into two parts by interfaces A10, A11, and A12. The first part 710 is defined by interfaces A10 and A11, and the second part 720 is defined by interfaces A11 and A12. The cross-sectional area of ​​interface A10 is larger than that of interface A11, and the cross-sectional area of ​​interface A11 is smaller than that of interface A12. The cross-sectional area of ​​section A13, located between interfaces A11 and A12, is substantially the same as that of interface A12. The first part 710 is a first cage-like structure 500, and the second part 720 is a second cage-like structure 600. The cross-sectional area of ​​the first cage-like structure 500 gradually decreases from the proximal end to the distal end; the cross-sectional area of ​​the second cage-like structure 600 first increases and then remains constant from the proximal end to the distal end.

[0061] In some embodiments, the stiffness of the first branch segment 310 is greater than that of the second branch segment 320. The first branch segment 310 and the second branch segment 320 are integrally formed from a shape memory alloy (e.g., nickel-titanium alloy). In the transport state, the first branch segment 310 and the second branch segment 320 can be retracted into a sheath (transport device). Upon reaching the target point, they can be released and automatically unfolded into a preset shape. For example, multiple first branch segments 310 can be released and unfolded to form a first cage structure 500. The first cage structure 500 can cover and protect the reference electrode 410 and isolate the reference electrode 410 from the tissue. Multiple second branch segments 320 can be released and unfolded to form a second cage structure 600.

[0062] The stiffness of the first branch segment 310 is greater than that of the second branch segment 320. The second branch segment 320 has lower stiffness, a lower flexural modulus, and higher flexibility, making it easier to deform and conform to irregular tissue surfaces. This allows for stable contact with low-stress tissues, ensuring that the ring electrode 400 on the second branch segment 320 can capture high-quality, high signal-to-noise ratio electrophysiological signals.

[0063] The first branch segment 310 has high rigidity, which gives it better support and resistance to deformation. When the second branch segment 320 is subjected to radial force during the process of contacting the tissue, the first branch segment 310 can effectively resist the deformation caused by it, ensuring that the multiple first branch segments 310 can continuously and stably maintain their preset first cage structure 500 to completely surround the reference electrode 410, avoid baseline shift caused by the reference electrode 410 contacting the tissue, and provide a stable potential reference for the system.

[0064] In this embodiment, by designing the distal branch 300 as a first branch segment 310 and a second branch segment 320 with different stiffnesses, precise functional zoning and synergistic effects are achieved. Specifically, the lower flexural modulus of the second branch segment 320 facilitates its adaptive contact with the tissue surface, thereby ensuring sufficient contact between the ring electrode 420 disposed thereon and the tissue, and acquiring high-quality electrophysiological signals. Simultaneously, the higher stiffness of the first branch segment 310 allows it to maintain a stable cage-like structure. This cage-like structure effectively masks the reference electrode 410, preventing it from contacting the tissue and thus avoiding signal interference and baseline drift caused by contact. This, in turn, improves the overall accuracy and reliability of electrophysiological mapping.

[0065] In this embodiment, there are several ways to achieve different stiffnesses in each segment of the distal branch 300. One method is to utilize shape memory alloy heat treatment for shaping. By applying different heat treatment parameters to the first branch segment 310 and the second branch segment 320, for example, applying a higher heat treatment temperature and / or subjecting the first branch segment 310 to a longer holding time, the stiffness of the first branch segment 310 can be made greater than that of the second branch segment 320. In this implementation, the cross-sectional areas of the first branch segment 310 and the second branch segment 320 are basically the same.

[0066] The second implementation method involves controlling the stiffness of the first branch segment 310 and the second branch segment 320 by varying the cross-sectional area, such as... Figure 9As shown, the cross-sectional area of ​​the first branch segment 310 is greater than that of the second branch segment 320. When the cross-sectional shapes of the first branch segment 310 and the second branch segment 320 are substantially the same, the larger the cross-sectional area of ​​the first branch segment 310, the smaller the deformation. For example, the thickness of the first branch segment 310 along the radial direction of the outer conduit 100 is greater than the thickness of the second branch segment 320 along the radial direction of the outer conduit 100, or the width of the first branch segment 310 along the circumferential direction of the outer conduit 100 is greater than the width of the second branch segment 320 along the circumferential direction of the outer conduit 100, so that the cross-sectional area of ​​the first branch segment 310 is greater than that of the second branch segment 320, thereby making the stiffness of the first branch segment 310 greater than the height of the second branch segment 320. In this implementation, the thickness or width of the first branch segment 310 can be the same or different at various points, for example, using a gradient structure. Similarly, the thickness or width of the second branch segment 320 can be the same or different at various points, for example, using a gradient structure. When the thickness or width of the first branch segment 310 adopts a gradient structure, and / or the thickness or width of the second branch segment 320 also adopts a gradient structure, it is necessary to ensure that the minimum stiffness of the first branch segment 310 is greater than the maximum stiffness of the second branch segment 320, so that the second branch segment 320 can be more easily deformed to fit against the tissue, while the first branch segment 310 has a higher resistance to deformation to maintain the cage structure and cover the reference electrode 410 from contacting the tissue.

[0067] Of course, when the cross-sectional areas of the first branch segment 310 and the second branch segment 320 are the same, the stiffness of the first branch segment 310 can be made to be greater than that of the second branch segment 320 by using different cross-sectional shapes.

[0068] In some embodiments, such as Figure 2 , Figure 3 and Figure 5 As shown, when the central axis 200 is an infusion catheter, the axial distance from the reference electrode 410 to the distal end of the infusion catheter (central axis 200) is greater than a preset value D. In this embodiment, the reference electrode 410 is arranged at a certain distance from the distal end of the infusion catheter, so that the reference electrode 410 is at a certain distance from the distal end of the infusion catheter where it is most likely to come into contact with the tissue, so as to avoid the reference electrode 410 from contacting the tissue.

[0069] The distal end of the perfusion catheter is typically designed as a saline perfusion outlet, during which saline is continuously perfused. If the reference electrode 410 is too close to this perfusion outlet, it will be completely submerged in the perfused saline, affecting its contact with blood and resulting in inaccurate reference electrical signals. Maintaining an appropriate distance between the reference electrode 410 and the distal perfusion outlet of the perfusion catheter ensures that the reference electrode 410 is in a representative blood environment, thereby obtaining a true and stable reference electrical signal. In this embodiment, the preset value D ranges from 0.2 to 0.6 mm. This distance range allows the reference electrode 410 to contact blood while reducing the risk of contact with tissue.

[0070] In some embodiments, the axial distance from the reference electrode 410 to the distal end of the first cage structure 500 is less than the axial distance from the distal end of the first cage structure 500 to the distal end of the external conduit 100. The reference electrode 410 is mounted inside the first cage structure 500, and the axial distance from the reference electrode 410 to the distal end of the first cage structure 500 is designed to be less than the axial distance from the distal end of the first cage structure 500 to the distal end of the external conduit 100; this arrangement constitutes a depth isolation design. During operation, even if the distal end of the first cage structure 500 deforms under the action of the second branch segment 320 and comes into contact with tissue, this contact point is far from the internal reference electrode 410, achieving physical isolation between the reference electrode 410 and the tissue, protecting the reference electrode 410 from contact with tissue, effectively avoiding signal short circuits or baseline drift caused by tissue contact, and providing a more stable electrical signal reference for the system.

[0071] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0072] It should be noted that the above embodiments can be freely combined as needed. The above description is only a preferred embodiment of this application. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. A mapping catheter, characterized in that, include: External catheter; The central axis is located proximally within the external conduit and extends distally from the distal end of the external conduit. Multiple distal branches are arranged circumferentially at the distal end of the external catheter and around the central axis. Each distal branch includes a first branch segment and a second branch segment. The proximal end of the first branch segment is connected to the distal end of the external catheter, and the distal end of the first branch segment is connected to the proximal end of the second branch segment. The distal ends of the multiple first branch segments are all inclined toward the central axis of the external catheter to form a first cage-like structure. The reference electrode is disposed outside the central axis and located within the first cage structure.

2. The mapping catheter according to claim 1, characterized in that, The first cage-like structure is truncated conical in shape, and the cross-sectional area of ​​the proximal end of the first cage-like structure is larger than the cross-sectional area of ​​the distal end of the first cage-like structure.

3. A mapping catheter according to claim 1, characterized in that, The cross-sectional area of ​​the first cage-like structure gradually increases and then gradually decreases from the proximal end to the distal end.

4. A mapping catheter according to claim 1, characterized in that, The stiffness of the first branch segment is greater than the stiffness of the second branch segment.

5. A mapping catheter according to claim 4, characterized in that, The cross-sectional area of ​​the first branch segment is greater than the cross-sectional area of ​​the second branch segment.

6. A mapping catheter according to any one of claims 1-5, characterized in that, When the central axis is an infusion catheter, the axial distance from the reference electrode to the distal end of the infusion catheter is greater than a preset value.

7. A mapping catheter according to any one of claims 1-5, characterized in that, The axial distance from the reference electrode to the distal end of the first cage structure is less than the axial distance from the distal end of the first cage structure to the distal end of the external conduit.

8. A mapping catheter according to any one of claims 1-5, characterized in that, It also includes multiple ring electrodes, with one or more of the ring electrodes provided on each of the second branch segments.

9. A mapping catheter according to any one of claims 1-5, characterized in that, Multiple second branch segments are arranged to form a second cage-like structure, which is cylindrical, frustum-shaped, or trumpet-shaped.

10. A mapping catheter according to any one of claims 1-5, characterized in that, Multiple second branch segments are arranged to form a second cage-like structure; The cross-sectional area of ​​the second cage structure increases from the proximal end to the distal end and then remains constant; or the cross-sectional area of ​​the second cage structure increases from the proximal end to the distal end and then decreases; or the cross-sectional area of ​​the second cage structure decreases from the proximal end to the distal end and then increases.

Images