Medical catheter

Abstract

The application provides a medical catheter, which comprises a distal shaping section with a shape memory function and a plurality of ring electrodes sleeved on the distal shaping section; the distal shaping section comprises a lumen and a shaping wire penetrating into the lumen; the shaping wire comprises a hook section, a ring section and a straight rod section, the hook section is connected to the distal end of the ring section, and the distal end of the hook section is deflected towards the center of the ring section, so that the orthographic projection of the hook section on the ring section is located in the ring section; the straight rod section is connected to the proximal end of the ring section, and the straight rod section is parallel to or coincides with the center line of the ring section; a plurality of the ring electrodes are distributed on the lumen. Through the special structure design of the distal shaping section, the medical catheter provided by the application has the characteristics of high safety factor, convenient operation and wide application range.

Description

Technical Field

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

[0002] Atrial fibrillation is a common cardiac arrhythmia. Currently, pulmonary vein ablation via electrophysiological ablation catheters is a common treatment method for these patients. The ablation procedure requires appropriate electrophysiological mapping catheters to locate the pulmonary vein ostia, acquire intracardiac electrical signals, and monitor the ablation effect. Designing and manufacturing suitable mapping catheters to quickly and effectively monitor cardiac electrical activity at the pulmonary vein ostia, while simplifying the procedure and improving efficiency, is an important requirement for clinicians. Summary of the Invention

[0003] The purpose of this invention is to provide a medical catheter to solve one or more problems in the prior art.

[0004] Based on the above ideas, the present invention provides a medical catheter, the medical catheter including a distal shaping segment with shape memory function and a plurality of ring electrodes sleeved on the distal shaping segment;

[0005] The distal shaping section includes a cavity tube and a shaping wire passing through the cavity tube;

[0006] The shaping wire includes a hook section, an annular section, and a straight section. The hook section is connected to the distal end of the annular section, and the distal end of the hook section is deflected toward the center of the annular section, such that the orthographic projection of the hook section onto the annular section is located within the annular section. The straight section is connected to the proximal end of the annular section, and the straight section is parallel to or coincides with the centerline of the annular section.

[0007] Multiple ring electrodes are spaced apart on the cavity.

[0008] Optionally, in the medical catheter, the shaping wire further includes a transition section, through which the straight rod section is transitionally connected to the annular coil section. The transition section is used to limit the displacement of the hook section, so that there is no overlap between the multiple annular electrodes on the lumen.

[0009] Optionally, in the medical catheter, the transition section includes a deflection section and an inner hook section. The straight rod section, the deflection section, the inner hook section, and the annular section are sequentially connected. The proximal end of the inner hook section is deflected toward the center of the annular section, and its orthographic projection on the annular section is located within the annular section. The inner hook section is used to limit the displacement of the hook section, so that there is no overlap between the multiple annular electrodes on the lumen.

[0010] Optionally, in the medical catheter, the shaping wire is configured such that, in its free state, on the orthographic projection of the annular segment, the straight rod segment lies in a quadrant that does not overlap with the quadrant containing the hooked section or the inner hooked section, and after being inserted into the lumen, the straight rod segment coincides with the centerline of the annular segment. Optionally, in the medical catheter, the radius of curvature of the orthographic projections of the deflection segment and the inner hooked section on the annular segment is equal.

[0011] Optionally, in the medical catheter, the edge of the ring electrode is smoothly connected to the lumen via an adhesive.

[0012] Optionally, in the medical catheter, the shaping wire further includes a limiting portion located at the distal end of the shaping wire to define the relative position of the lumen and the shaping wire.

[0013] Optionally, in the medical catheter, the outer periphery of the limiting portion is smoothly connected to the lumen via an adhesive.

[0014] Optionally, in the medical catheter, the surface layer of the shaping filament is an insulating layer.

[0015] Optionally, in the medical catheter, the annular segment has a threaded structure, and the number of threads in the threaded structure ranges from 1 to 3.

[0016] Optionally, in the medical catheter, the medical catheter further includes a main tube, and the lumen includes a flared area at the proximal end. The lumen is sleeved on the distal end of the main tube through the flared area, so that the lumen and the main tube are transitionally connected.

[0017] Optionally, in the medical catheter, the medical catheter further includes a protective tube, which is inserted inside the main tube, and the wire of the ring electrode passes through the protective tube and exits from the proximal end of the main tube.

[0018] Optionally, in the medical catheter, the lumen includes a straight rod region for passing through the straight rod segment, and the flared region is located at the distal end of the straight rod region; the protective tube extends through the flared region to a predetermined distance within the straight rod region.

[0019] Optionally, in the medical catheter, the preset distance ranges from 2mm to 10mm.

[0020] Optionally, in the medical catheter, the medical catheter further includes a straightening tube and a torsion device sleeved on the main tube. The proximal end of the straightening tube is connected to the distal end of the torsion device. The torsion device limits the movement of the straightening tube relative to the main tube by tightening or loosening it relative to the main tube. The straightening tube is used to change the distal shaping section from a free state to a controlled shape state.

[0021] Optionally, in the medical catheter, the torsion device includes an upper part and a lower part. The distal end of the upper part is connected to the straightening tube, and the proximal end of the upper part is threadedly connected to the distal end of the lower part. The distal end of the lower part has a multi-lobed structure. The lower part is screwed relative to the upper part so that when the multi-lobed structure abuts against the main tube, it limits the movement of the straightening tube relative to the main tube.

[0022] In summary, the medical catheter provided by the present invention includes a distal shaping segment with shape memory function and a plurality of loop electrodes sleeved on the distal shaping segment; the shaping wire includes a hook segment, an annular segment and a straight rod segment, the hook segment is connected to the distal end of the annular segment, and the distal end of the hook segment is deflected toward the center of the annular segment, such that the orthographic projection of the hook segment on the annular segment is located within the annular segment; the straight rod segment is connected to the proximal end of the annular segment, and the straight rod segment is parallel to or coincides with the centerline of the annular segment; the plurality of loop electrodes are spaced apart on the lumen.

[0023] Compared with existing technologies, it has the following advantages:

[0024] (1) The medical catheter provided by the present invention has the distal end of the hook section of the distal shaping section located within the annular section. When the doctor rotates the catheter in reverse, the catheter tip will not insert into the tissue surface. In addition, during the operation of the catheter, the tip is not easily entangled with the annular section, thus avoiding the impact on the acquisition of electrical signals due to the overlapping of the annular electrodes.

[0025] (2) Furthermore, the medical catheter provided by the present invention also includes a transition section, which allows the annular section and the straight rod section to be smoothly connected, avoiding the reduction of the service life of the catheter due to the bending of the shaping wire used to form the distal shaping section or the catheter tip lead wire. Moreover, when the hook section moves closer to the straight rod section due to tissue compression, the transition section can play a blocking role, further avoiding the deformation of the hook section from entanglement with the annular section, causing the ring electrodes to overlap with each other, thereby affecting the accuracy of mapping or ablation.

[0026] (3) Further, the transition section includes a deflection section and an inner hook section. The straight rod section is sequentially connected to the annular section through the deflection section and the inner hook section. The shaping wire is configured such that, in a free state, the position of the orthographic projection of the straight rod section on the annular section can be changed by the deflection of the deflection section. That is, the transition section can make the distal shaping section a central structure or an eccentric structure, which can meet the mapping of different pulmonary vein structures.

[0027] (4) Furthermore, the arc radius of the deflection segment and the inner hook segment projected onto the annular segment is equal, so that the annular segment and the straight rod segment present a better smooth transition effect, avoiding the bending of the shaping wire or the guide wire at the end of the guide tube, which would reduce the service life of the guide tube.

[0028] (5) A protective tube is installed inside the main tube of the catheter. The protective tube isolates the shaping wire and the ring electrode wire extending into the main tube from the inner wall of the main tube, ensuring the electrical insulation performance of the main tube and reducing signal interference. The protective tube extends into the straight rod area of ​​the cavity tube where the straight rod section is installed, which can increase the connection strength between the main tube and the cavity tube, and at the same time provide support and protection for the straight rod area.

[0029] (6) The edge of the ring electrode is smoothed with adhesive to avoid the edge of the ring electrode rubbing against the tissue and increase the safety of the catheter. Attached Figure Description

[0030] Figure 1 This is a schematic diagram showing the use of a loop catheter and a balloon catheter together.

[0031] Figure 2 A schematic diagram of the structure of a medical catheter provided in an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the structure of the distal shaping segment in an embodiment of the present invention;

[0033] Figure 4 This is a top view of the distal end of the shaping segment in an embodiment of the present invention;

[0034] Figure 5 This is a side view of the distal shaping segment in an embodiment of the present invention;

[0035] Figure 6 This is a cross-sectional view of the distal shaping section in an embodiment of the present invention;

[0036] Figure 7 This is a cross-sectional view of the straight rod segment and the main body segment in an embodiment of the present invention;

[0037] Figure 8 This is an anatomical diagram of the torsion device in an embodiment of the present invention;

[0038] Figure 9 This is a cross-sectional view of the torsion device in an embodiment of the present invention;

[0039] The annotations for each of the attached figures are explained below:

[0040] 1-Ring electrode; 2-Distal shaping section; 3-Main tube; 4-Straightening tube; 5-Torquer; 6-Socket;

[0041] 7-Limiting section; 8-Returning section; 9-Annular section; 10-Deflection section; 11-Inner hook section; 12-Straight rod section;

[0042] 13-Glue ball; 14-Insulation layer; 15, 17-Adhesive; 16-Wire;

[0043] 18-Protective tube; 19-Cavity tube; 20-Shaping wire;

[0044] 21 - Upper component; 22 - Lower component. Detailed Implementation

[0045] The purpose of this invention is to provide a high-safety medical catheter, which is a loop catheter that can be used for pulmonary vein electrocardiogram signal monitoring. It can be used alone or in conjunction with other ablation catheters. For example, ... Figure 1 As shown, this loop catheter (e.g., a loop mapping catheter) can be used in conjunction with a balloon catheter (e.g., a balloon ablation catheter or other similarly structured catheter) to reach the heart through the intraluminal channel of the balloon ablation catheter, helping the balloon ablation catheter locate the pulmonary veins and monitor the catheter ablation effect. This application uses pulmonary vein electrocardiogram signal monitoring as an example; those skilled in the art will understand that this catheter can also be used for mapping other sites, and it can be adapted to different ablation energy sources, such as radio frequency, pulse, and microwave energy; this application does not impose any limitations in this regard.

[0046] To make the objectives, advantages, and features of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to facilitate and clearly illustrate the objectives of the embodiments of this invention. Furthermore, the structures shown in the drawings are often part of the actual structures. In particular, different figures may emphasize different aspects and sometimes use different scales. It should also be understood that, unless specifically stated or indicated, the terms "first," "second," "third," etc., in the specification are only used to distinguish the various components, elements, steps, etc., in the specification, and are not used to indicate the logical or sequential relationships between the various components, elements, steps, etc.

[0047] In this application, "proximal" and "distal" refer to the relative orientation, position, and direction of the components or movements relative to each other from the perspective of the physician using the medical device. Although "proximal" and "distal" are not restrictive, "proximal" usually refers to the end of the medical device that is closer to the physician during normal operation, while "distal" usually refers to the end that first enters the patient's body.

[0048] Please see Figure 2 This invention provides a medical catheter, which includes a distal shaping segment 2 with shape memory function and a plurality of ring electrodes 1 disposed on the distal shaping segment 2. See also... Figure 7 The distal shaping section 2 includes a cavity tube 19 and a shaping wire 20 passing through the cavity tube 19.

[0049] In addition, please continue to see Figure 2 The medical catheter provided in this embodiment may further include: a main tube 3, a straightening tube 4, a torsion device 5, and a socket 6. For a detailed description of the main tube 3, the straightening tube 4, the torsion device 5, and the socket 6, please refer to the following sections.

[0050] Please refer to Figure 3 The shaping wire 20 includes: a hook section 8, an annular section 9, and a straight section 12. The hook section 8 is connected to the distal end of the annular section 9, and the distal end of the hook section 8 is deflected toward the center of the annular section 9, such that the orthographic projection of the hook section 8 onto the annular section 9 (e.g., ...) Figure 4 (As shown in the diagram) is located within the annular segment 9. The straight rod segment 12 is connected to the proximal end of the annular segment 9, and the straight rod segment 12 is parallel to or coincides with the center line of the annular segment 9.

[0051] In the medical catheter provided in this embodiment of the invention, the distal end of the hook section 8 of the distal shaping section 2 is located within the annular section 9. When the doctor rotates the catheter in the reverse direction (for example, when the catheter tip is rotated toward the tissue), the catheter tip will not insert into the tissue surface and cause damage to the tissue.

[0052] Furthermore, in existing technologies, during catheter manipulation, the catheter tip is easily moved due to compression from internal tissues, causing it to become entangled with the annular segment 9. This results in overlap between the annular electrodes on the lumen 19, affecting the acquisition of electrical signals. In this embodiment, however, the catheter tip is a hook segment 8, whose orthogonal projection on the annular segment 9 is located within the annular segment 9. When the hook segment 8 is subjected to slight compression, its distal end moves within the annular segment 9, making it difficult to become entangled with the annular segment. Therefore, overlap between the annular electrodes on the lumen 19 can be avoided to a certain extent, thus preventing interference with the acquisition of electrical signals.

[0053] In this embodiment, preferably, the plurality of ring electrodes are spaced apart on the cavity 19 of the annular segment 9, thereby further avoiding the interference of the hook segment 8 and the annular segment 9 with the acquisition of electrical signals due to entanglement.

[0054] Furthermore, in the medical catheter provided in this embodiment, the inner shaping wire 20 further includes a transition section, through which the straight rod section 12 is transitionally connected to the annular coil section 9. The transition section is used to limit the displacement of the hook section 8, so that there is no overlap between the plurality of annular electrodes 1 on the lumen 19.

[0055] Specifically, the distal end of the catheter may deform due to catheter rotation or tissue compression, causing it to become entangled with the annular segment 9. For example, when the distal end of the catheter moves below the annular segment 9 (the lower part of the annular segment 9 refers to the side near the straight rod segment 12) and drives the annular segment 9 to move, the distal portion of the annular segment 9 may overlap with other parts of the annular segment 9, resulting in overlapping of the ring electrodes 1 on the lumen 19, affecting the accuracy of mapping or ablation. In the medical catheter provided in this embodiment, when the distal shaping segment 2 is within the tissue and is compressed, the hooked segment 8 moves towards the annular segment 9 until it reaches the transition segment. The transition segment then blocks the annular segment 9, preventing the hooked segment 8 from moving further below the annular segment 9 and becoming entangled with it. This avoids overlapping of the different parts of the annular segment 9, which could affect the accuracy of mapping or ablation due to overlapping of the ring electrodes 1. Therefore, in this embodiment, the transition section not only realizes the transition connection between the straight rod section 12 and the annular section 9, but also further avoids the deformation of the hook section 8 causing it to become entangled with the annular section 9, resulting in the overlapping of the ring electrodes and thus affecting the accuracy of the calibration or ablation.

[0056] For further details, please refer to [link / reference]. Figure 3 The transition section includes a deflection section 10 and an inner hook section 11. The straight rod section 12, the deflection section 10, the inner hook section 11, and the annular section 9 are sequentially connected, that is, the straight rod section 12 is sequentially connected to the distal end of the annular section 9 through the deflection section 10 and the inner hook section 11. The proximal end of the inner hook section 11 is deflected towards the center of the annular section 9, and its orthographic projection on the annular section 9 (e.g., Figure 4As shown, located within the annular segment 9, when the hooked segment 8 moves towards the annular segment 9 due to tissue compression, the inner hooked segment 11 limits the displacement of the straight rod segment 12, ensuring that the multiple annular electrodes 1 on the cavity 19 do not overlap. That is, when the hooked segment 8 moves towards the annular segment 9 to abut against the inner hooked segment 11, or drives the annular segment 9 to move until the distal portion of the annular segment 9 abuts against the inner hooked segment 11, the position of the hooked segment 8 no longer changes. This limits the hooked segment 8 from wrapping around the underside of the annular segment 9 to a certain extent, thus preventing the overlapping of the annular electrodes 1 due to overlapping of different parts of the annular segment 9, which could affect the accuracy of mapping or ablation.

[0057] Understandably, the inner hook section 11, the annular section 9, and the back hook section 8 are connected sequentially to form a threaded structure. The annular section 9 forms a relatively complete full-turn thread, while the inner hook section 11 and the back hook section 8 are located on both sides of the annular section 9 and form relatively incomplete threads, such as 1 / 4, 1 / 5, or 1 / 6 of the full-turn thread. In this way, a smooth transition connection can be ensured between the inner hook section 11, the annular section 9, and the back hook section 8, giving the conduit good bending resistance.

[0058] Preferably, in this embodiment, the shaping wire 20 is configured such that, in its free state, on the orthographic projection plane of the annular segment 9, the straight rod segment 12 is located in a quadrant of the annular segment 9 that does not overlap with the quadrant where the hook segment 8 is located or the quadrant where the inner hook segment 11 is located. Specifically, as shown... Figure 4 As shown, the orthographic projection plane of the annular segment 9 is divided into four quadrants: the first quadrant, the second quadrant, the third quadrant, and the fourth quadrant. If the hook segment 8 is located in the third quadrant and the inner hook segment 11 is located in the fourth quadrant on the orthographic projection plane of the annular segment 9, then in the free state before the annular segment 9 enters the cavity tube 19, the orthographic projection of the straight rod segment 12 on the annular segment 9 is located in the first quadrant or the second quadrant. After entering the cavity tube 19, the straight rod segment 12 coincides with the center line of the annular segment 9, that is, on the orthographic projection plane of the annular segment 9, the straight rod segment 12 is located at the center O1 of the annular segment 9.

[0059] Because the shaping wire 20 is relatively thin, the supporting force may be insufficient to resist the tension of the cavity tube 19. If the center line of the straight rod segment 12 coincides with that of the annular segment 9 when the shaping wire 20 is in a free state, then after the shaping wire 20 passes through the cavity tube 19, due to the influence of the hook segment 8, the straight rod segment 12 will no longer coincide with the center line of the annular segment 9. That is, on the orthographic projection plane of the annular segment 9, the straight rod segment 12 will deviate from the center O1 of the annular segment 9 and move to... Figure 4 The third or fourth quadrant shown in the diagram. In this embodiment, the shaping wire 20 is configured such that, in its free state, on the orthographic projection plane of the annular segment 9, the straight rod segment 12 is located in the first or second quadrant of the annular segment 9, which does not overlap with the third quadrant where the hook segment 8 is located and the fourth quadrant where the inner hook segment 11 is located. In this way, after the shaping wire 20 passes through the cavity tube 19, due to the influence of tension, the straight rod segment 12 moves towards the direction closer to the third and fourth quadrants, so that the straight rod segment 12 coincides with the center line of the annular segment 9.

[0060] In other embodiments, the shaping wire 20 may be configured such that, in its free state, the straight rod segment 12 coincides with the center of the annular segment 9 on its orthogonal projection plane; or, although the straight rod segment 12 is located in the first or second quadrant of the annular segment 9, the tension prevents it from reaching the center of the annular segment 9 or extends beyond the center of the annular segment 9 to the third or fourth quadrant; or the straight rod segment 12 is located within the third quadrant where the hook segment 8 is located or within the fourth quadrant where the inner hook segment 11 is located. This results in the distal shaping segment 2 formed by the shaping wire 20 passing through the lumen 19 having an eccentric structure, meaning the straight rod segment 12 deviates from the centerline of the annular segment 9. This configuration is suitable for some special pulmonary vein structures.

[0061] As can be seen from the above description, the position of the orthographic projection of the straight rod segment 12 on the annular segment 9 can be changed by the deflection of the deflection segment 10, that is, the distal shaping segment 2 can be a central structure or an eccentric structure, which can meet the mapping of different pulmonary vein structures.

[0062] In this embodiment, the cavity tube 19 can be a single-cavity tube, and the material of the shaping wire 20 can be a shape memory alloy. The shape memory alloy is heat-treated to obtain the shaping wire 20 with the target structural morphology. Preferably, please refer to... Figure 6 The surface of the shaping wire 20 is an insulating layer 14. That is, the shaping wire 20 can be formed by wrapping an insulating material on the surface of the shape memory alloy. The insulating layer 14 can ensure the insulation performance between the shaping wire 20 and the wire of the ring electrode 1.

[0063] The shaping wire 20 can be shaped using the following method: The dimensions of each segment (including the straight rod segment 12, the deflection segment 10, the inner hook segment 11, the annular segment 9, and the return hook segment 8) are designed according to the structure of the shaping wire 20; a shaping mold matching the designed structure is fabricated, and grooves with the same design dimensions are made on the shaping wire 20 mold, with each groove corresponding one-to-one with the design dimensions of each segment; the shape memory alloy is wound along the grooves and fixed with fixing bolts; then, after heat treatment at a certain time and temperature, it is rapidly cooled, and finally the fixing bolts are loosened to obtain the formed shaping wire 20.

[0064] For a better option, please continue reading. Figure 3 The shaping wire 20 further includes a limiting part 7, which is located at the distal end of the shaping wire 20 and is used to limit the relative position of the cavity tube 19 and the shaping wire 20. That is, when one end of the shaping wire 20 passes through the cavity tube 19 and moves to the distal end of the cavity tube 19 via the limiting part 7, the positions of the shaping wire 20 and the cavity tube 19 no longer change. Furthermore, to further ensure the connection strength between the cavity tube 19 and the shaping wire 20, please refer to [link to relevant documentation]. Figure 6 The distal end of the shaping wire 20 (i.e., where the limiting portion 7 is located) and the distal end of the lumen 19 can be fixedly connected by an adhesive 15, such as glue. Preferably, the limiting portion 7 is a ball-shaped tip to avoid damaging tissue with its surface contour. Furthermore, the outer periphery of the limiting portion 7 can be smoothly connected to the lumen 19 by the adhesive 15; that is, a rubber ball 13 can be formed at the distal end of the shaping wire 20, which wraps around the limiting portion 7 and extends into the lumen 19, thereby providing better tissue protection. In addition, the rubber ball 13 can also seal the distal end of the lumen 19, improving the sealing performance of the distal end of the medical catheter provided in this embodiment.

[0065] Additionally, please continue to see... Figure 6 The edge of the ring electrode 1 is smoothly connected to the single lumen tube 19 by adhesive 17 to avoid the edge of the ring electrode 1 scraping against other contact surfaces, thereby increasing the safety of the catheter.

[0066] In the medical catheter provided in this embodiment, the annular segment 9 can be a threaded structure, and the number of threads in the threaded structure ranges from 1 to 3 turns, preferably 1 to 1.2 turns. Figure 3 The example shown uses a thread structure with 1 thread turn.

[0067] In one specific embodiment, the thread radius r1 of the threaded structure can range from 5 to 15 mm, preferably 6 to 12 mm, and the thread pitch d can range from 0 to 5 mm, preferably 0 to 1 mm. Correspondingly, the radius of the orthographic projection (arc ab) of the hook segment 8 on the annular segment 9 ranges from 0 to 15 mm, preferably 3 to 8 mm, and the angle ∠aO2b ranges from 0 to 180°, preferably 30-90°, where O2 represents the center of the arc of the orthographic projection of the hook segment 8 on the annular segment 9. The inner hook segment 11 is projected onto the orthographic projection surface of the annular segment 9 (i.e.,...). Figure 4 The radius of the projection (arc b1c, where b and b1 may or may not coincide) on the mid-to-far top view is 0–15 mm, preferably 3–12 mm, and generally does not exceed the radius of the annular segment 9. The angle ∠b1O3c is 0–180°, preferably 60–120°. O3 is the center of the arc of the orthographic projection of the inner hook segment 11 onto the annular segment 9. When the arc radii of the orthographic projections of the inner hook segment 11 and the deflection segment 10 onto the annular segment 9 are equal, O3 is also the center of the arc of the orthographic projection of the deflection segment onto the annular segment 9. The radius of the orthographic projection (arc cO1) of the deflection segment 10 onto the annular segment 9 is 0–15 mm, preferably 3–12 mm. The angle ∠cO3O1 is 0–180°, preferably 60–120°. The deflection segment 10 is projected onto the straight rod segment 12 in the forward direction (i.e., Figure 5 The radius of the projection (arc ce) on the side view is 0-15mm, preferably 3-12mm, and the angle ∠cO4e is 0-180°, preferably 90-150°. In this case, the transition from the deflection segment 10 to the straight rod segment 12 is relatively smooth, resulting in less resistance during the straightening and pushing of the guide tube. The projection of the straight rod segment 12 onto the forward projection plane of the annular segment 9 is point O1, and the distance from point O1 to the annular ring is 0-15mm, preferably 0-5mm. The inner hook section 11 and the deflection section 10 are designed with an arc shape with a certain radius, which allows for a smooth transition between the annular section 9 and the straight rod section 12. This avoids the reduction in the service life of the catheter due to bending of the shaping wire 20 or the wire at the distal end of the catheter. Furthermore, the arc radius of the orthographic projection of the inner hook section 11 and the deflection section 10 onto the annular section 9 is equal, which further ensures the smoothness of the bending of the shaping wire 20.

[0068] In this embodiment, the ring electrode 1 distributed in the annular segment 9 has the effects of locating the pulmonary vein orifice, acquiring intracardiac electrical signals, and monitoring ablation. Preferably, the distal shaping segment 2 also includes a sensor (not shown), which is fitted onto the straight rod segment 12 and isolated from the outside via the lumen 19. The portion of the lumen 19 fitted onto the straight rod segment 12 is fitted with ring electrodes, such that at least two ring electrodes are located on either side of the sensor. Therefore, when the ring electrodes and the sensor work together, magneto-electric dual positioning technology can be achieved, and combined with corresponding three-dimensional equipment, a three-dimensional display function can be realized. To avoid increasing the maximum outer diameter of the catheter due to the sensor, preferably, a portion of the straight rod segment 12 can be thinned to form a thinned segment, and then the sensor can be fitted onto the thinned segment, so that the outer diameter of the thinned segment after the lumen 19 is fitted is not greater than the outer diameter at the junction of the distal shaping segment 2 and the main tube 3.

[0069] For further details, please continue to see Figure 2 The medical catheter provided in this embodiment also includes a main tube 3, and the distal shaping section 2 is connected to the main tube 3. Preferably, please refer to... Figure 7 The proximal end of the cavity tube 19 of the distal shaping section 2 is flared, that is, the proximal end of the cavity tube 19 has a flared area, and the cavity tube 19 is sleeved on the distal end of the main body tube 3 through the flared area, so that the cavity tube 19 and the main body tube 3 are transitionally connected.

[0070] After the ring electrode 1 is fitted onto the lumen 19, the wire 16 of the ring electrode 1 passes through the lumen 19 and the main body tube 3 in sequence and connects to the socket 6 located at the tail of the catheter. In order to ensure that the signal transmitted by the wire 16 is not interfered with, in this embodiment, the medical catheter also includes a protective tube 18. The protective tube 18 is inserted into the main body tube 3, and the wire of the ring electrode passes through the protective tube 18 to the proximal end of the main body tube. That is, the protective tube 18 is used to ensure the electrical insulation performance of the main body tube 3 and reduce signal interference. The protective tube 18 can be made of insulating material.

[0071] Additionally, the cavity 19 includes a straight rod section for through which the straight rod segment 12 passes. Figure 7 (Illustrated in part of the straight rod area), the flared area is located at the distal end of the straight rod area; preferably, the protective tube 18 extends through the flared area into the straight rod area by a predetermined distance, thereby increasing the connection strength between the main tube 3 and the lumen tube 19. More preferably, the predetermined distance is in the range of 2mm to 10mm. Within this range, the protective tube 18 will not affect the rigidity of the medical catheter due to excessive extension, nor will it affect the connection strength between the lumen tube 19 and the main tube 3 due to excessive shortness.

[0072] For further details, please continue reading. Figure 2 In conjunction with point 7, the medical catheter provided in this embodiment further includes: a straightening tube 4 and a torsion device 5. The straightening tube 4 and the torsion device 5 are sleeved on the main tube 3. The proximal end of the straightening tube 4 is connected to the distal end of the torsion device 5. The torsion device 5 limits the movement of the straightening tube 4 relative to the main tube 3 by tightening or loosening relative to the main tube 3. The straightening tube 4 is used to change the distal shaping segment 2 from a free state to a controlled shape state.

[0073] For details, please refer to [link / reference]. Figure 8 and Figure 9 The torsion device 5 may include an upper component 21 and a lower component 22. The distal end of the upper component 21 is connected to the straightening tube 4, specifically, by bonding or heat treatment. The proximal end of the upper component 21 is threadedly connected to the distal end of the lower component 22. The distal end of the lower component 22 has a multi-lobed structure. When the lower component 22 is tightened relative to the upper component 21, the multi-lobed structure abuts against the main body tube 3, limiting the movement of the straightening tube 4 relative to the main body tube.

[0074] In other embodiments, the torsion device 5 may include an openable component with an opening and a rotating member for changing the size of the opening of the openable component. The rotating member is threadedly connected to the openable component, which is sleeved on the main body tube 3. The rotating member changes the size of the opening by moving relative to the main body tube 3, thereby limiting the movement of the straightening tube 4 relative to the main body tube 3. That is, it is understood that the specific structure of the torsion device 5 does not constitute a limitation of this application.

[0075] The usage process of the medical catheter provided in this embodiment of the invention is as follows:

[0076] Loosen the torsion device 5 and move the straightening tube 4 along the main tube 3. Then change the distal shaping section 2 from a free state to a controlled state, so that the distal shaping section 2 changes from a ring shape to a straight or approximately straight shape that matches the shape of the straightening tube 4.

[0077] The medical catheter is inserted into the sheath and reaches the target tissue through the sheath. Then the sheath is removed, allowing the distal shaping segment 2 to return to its free state and perform mapping or ablation of the target tissue in a ring shape.

[0078] In summary, the medical catheter provided by this invention includes a distal shaping segment with shape memory function and multiple ring electrodes sleeved on the distal shaping segment. The distal shaping segment includes a lumen and a shaping wire inserted within the lumen. The shaping wire includes a hook segment, a loop segment, and a straight rod segment. The hook segment is connected to the distal end of the loop segment, and the distal end of the hook segment is deflected toward the center of the loop segment, such that the orthographic projection of the hook segment onto the loop segment is located within the loop segment. The straight rod segment is connected to the proximal end of the loop segment, and the straight rod segment is parallel to or coincides with the centerline of the loop segment. The multiple ring electrodes are spaced apart on the lumen. With the medical catheter provided by this invention, the distal end of the hook segment of the distal shaping segment is located within the loop segment. When the doctor rotates the catheter in reverse, the catheter tip will not insert into the tissue surface. Furthermore, during operation, the catheter tip is less likely to become entangled with the loop segment, avoiding overlap between the ring electrodes and affecting the acquisition of electrical signals. Thus, through the special structural design of the distal shaping section, the medical catheter provided by the present invention has the characteristics of high safety, convenient operation and wide applicability.

[0079] Furthermore, it should be understood that although the present invention has been disclosed above with reference to preferred embodiments, these embodiments are not intended to limit the present invention. For any person skilled in the art, many possible variations and modifications can be made to the technical solutions of the present invention based on the disclosed technical content, or equivalent embodiments with equivalent changes, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention shall still fall within the scope of protection of the present invention.

Claims

1. A medical catheter, characterized in that, The medical catheter includes a distal shaping segment with shape memory function and multiple ring electrodes sleeved on the distal shaping segment; The distal shaping section includes a cavity tube and a shaping wire passing through the cavity tube; The shaping wire includes a hook section, an annular section, and a straight section. The hook section is connected to the distal end of the annular section, and the distal end of the hook section is deflected toward the center of the annular section, such that the orthographic projection of the hook section onto the annular section is located within the annular section. The straight section is connected to the proximal end of the annular section, and the straight section is parallel to or coincides with the centerline of the annular section. Multiple ring electrodes are spaced apart on the cavity tube; The shaping wire also includes a transition section, through which the straight rod section is connected to the annular section. The transition section is used to limit the displacement of the hook section towards the annular section, so as to prevent the hook section from entangled with the annular section, thereby preventing the multiple annular electrodes on the cavity tube from overlapping.

2. The medical catheter as described in claim 1, characterized in that, The transition section includes a deflection section and an inner hook section. The straight rod section, the deflection section, the inner hook section and the annular section are sequentially connected. The proximal end of the inner hook section deflects toward the center of the annular section, and its orthographic projection on the annular section is located within the annular section. The inner hook section is used to limit the displacement of the return hook section, so that there is no overlap between the multiple annular electrodes on the cavity tube.

3. The medical catheter as described in claim 2, characterized in that, The shaping wire is configured such that, in its free state, on the orthographic projection of the annular segment, the straight rod segment is located in a quadrant that does not overlap with the quadrant where the hook segment and the inner hook segment are located, and after being inserted into the cavity tube, the straight rod segment coincides with the center line of the annular segment.

4. The medical catheter as described in claim 2 or 3, characterized in that, The radius of the arc of the deflection segment and the inner hook segment projected onto the annular segment is equal.

5. The medical catheter as described in claim 1, characterized in that, The edge of the ring electrode is smoothly connected to the cavity tube by an adhesive.

6. The medical catheter as described in claim 1, characterized in that, The shaping wire also includes a limiting part, which is located at the distal end of the shaping wire and is used to limit the relative position of the cavity tube and the shaping wire.

7. The medical catheter as described in claim 6, characterized in that, The outer periphery of the limiting part is smoothly connected to the cavity tube by an adhesive.

8. The medical catheter as described in claim 1, characterized in that, The surface layer of the shaping wire is an insulating layer.

9. The medical catheter as described in claim 1, characterized in that, The annular segment has a threaded structure, and the number of threaded turns in the threaded structure ranges from 1 to 3.

10. The medical catheter as claimed in claim 1, characterized in that, The medical catheter also includes a main tube, and the lumen includes a flared area at the proximal end. The lumen is sleeved onto the distal end of the main tube through the flared area, so that the lumen and the main tube are transitionally connected.

11. The medical catheter as claimed in claim 10, characterized in that, The medical catheter also includes a protective tube, which is inserted inside the main tube, and the lead wire of the ring electrode passes through the protective tube and exits from the proximal end of the main tube.

12. The medical catheter as claimed in claim 11, characterized in that, The cavity tube includes a straight rod section for passing through the straight rod segment, and the flared section is located at the distal end of the straight rod section; the protective tube extends through the flared section to a predetermined distance within the straight rod section.

13. The medical catheter as described in claim 12, characterized in that, The preset distance ranges from 2mm to 10mm.

14. The medical catheter as claimed in claim 10, characterized in that, The medical catheter also includes a straightening tube and a torsion device fitted onto the main tube. The proximal end of the straightening tube is connected to the distal end of the torsion device. The torsion device limits the movement of the straightening tube relative to the main tube by tightening or loosening it relative to the main tube. The straightening tube is used to change the distal shaping section from a free state to a controlled state.

15. The medical catheter as described in claim 14, characterized in that, The torsion device includes an upper part and a lower part. The distal end of the upper part is connected to the straightening tube, and the proximal end of the upper part is threadedly connected to the distal end of the lower part. The distal end of the lower part has a multi-lobed structure. The lower part is screwed relative to the upper part so that when the multi-lobed structure abuts against the main tube, it limits the movement of the straightening tube relative to the main tube.

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