Catheter capable of deflecting in multiple directions

Abstract

The invention provides a catheter capable of deflecting in multiple directions, the catheter comprises a slender cannula, the cannula is provided with a near end and a far end, the cannula sequentially comprises a main body section and a far side section in the direction from the near end to the far end, and at least part of the far side section is a flexible section; the handle part is connected to the near end of the cannula; the more than four stay wires extend along the longitudinal direction and are arranged in the wall of the cannula, the far ends of the stay wires are fixedly connected to the far side section, the more than four stay wires are uniformly arranged at intervals, and the more than four stay wires are controlled by the handle part to longitudinally move relative to the main body section so as to drive the flexible section to deflect to any direction and any angle.

Description

Technical Field

[0001] The invention relates to medical instruments, in particular to a catheter capable of being deflected in multiple directions. Background Art

[0002] At present, ureteral guide sheath and ureteral soft endoscope are mainly used in natural cavity soft endoscope surgery. The ureteral guide sheath enters the urinary cavity through the patient's urethra to establish an effective channel so that surgical instruments such as ureteral soft endoscope can smoothly enter and exit the urinary cavity for surgical operation. During the operation, the existing technology is that water enters the working channel of the endoscope, and water flows out of the gap between the endoscope and the sheath tube, forming a negative pressure suction to suck away the gravel hit by the laser in time. The head end of the existing sheath tube is a soft end, which is driven by the bending part of the soft endoscope to bend. The existing snake bone is designed as a laser-cut metal tube or a riveted metal part. During the bending process, there will be gaps between each section of the snake bone, which may cause accidental damage when closing. A protective tube is also needed outside the snake bone to prevent the snake bone from scratching the tissue, but the protective tube needs to adapt to the bending of the snake bone, which will cause it to be prone to wrinkling. The wrinkles may cause obstruction or slight damage during the process of entering and exiting the urinary system.

[0003] In current endoscopic surgeries, to reach the target position, the head end is deflected in the up and down and left and right directions through the snake bone, and at the same time cooperates with the rotating handle. In difficult-to-reach positions, the doctor needs to rotate the handle continuously, which puts a heavy burden on the doctor's arm. At the same time, the tube body is easily damaged during the continuous twisting process. In addition, the bending angle of the snake bone is relatively single, and the soft mirror and sheath need to be rotated frequently to adjust the direction, which is cumbersome to operate. Summary of the invention

[0004] The present invention provides a multi-directionally deflectable catheter, comprising:

[0005] An elongated cannula, the cannula having a proximal end and a distal end, the cannula including a main body section and a distal section in sequence from the proximal end toward the distal end, at least part of the distal section being a flexible section; a handle portion, the handle portion being connected to the proximal end of the cannula;

[0006] At least four pull wires extend longitudinally and are arranged in the wall of the cannula. The distal ends of the pull wires are fixedly connected to the distal segment. The at least four pull wires are evenly spaced. The pull wires are controlled by the handle to move longitudinally relative to the main segment to drive the flexible segment to deflect to any direction and any angle.

[0007] The present invention uses at least four pull wires to allow the flexible segment to cover a wider range of directions, meeting the needs for different angles in medical surgery. When dealing with complex surgical cases, such as navigation within narrow or tortuous anatomical structures, the design of at least four pull wires can achieve multi-directional simultaneous operation, allowing the catheter to flexibly respond to different surgical needs and real-time changes, effectively improving the success rate of the operation.

[0008] In some embodiments, the distal segment includes a flexible segment and a head end from the proximal end to the distal end, the head end is connected to the distal end of the flexible segment, and the distal end of the pull wire is connected to the distal end or the head end of the flexible segment.

[0009] In some embodiments, a pull wire outer tube is fixed inside the tube wall of the cannula, the pull wire extends longitudinally inside the pull wire outer tube, and the proximal end of the pull wire is controlled by the handle.

[0010] In some embodiments, the head end has a circumferential fixing member, and at least four pull wires are fixedly connected to the circumferential fixing member at circumferential intervals.

[0011] In some embodiments, the main body segment is a rigid tube segment; preferably, the rigid tube segment includes a proximal segment and a distal segment, and the hardness of the distal segment is smaller than that of the proximal segment.

[0012] In some embodiments, the tube wall of the flexible segment includes an outer tube, a support layer and an inner tube, the support layer is formed between the outer tube and the inner tube layer, and the pull wires are arranged inside or in the gap between the outer tube, the support layer and the inner tube.

[0013] In some embodiments, the support layer is an elastic layer.

[0014] In some embodiments, the head end includes an outer tube, a circumferential fixing member and an inner tube, the circumferential fixing member is arranged between the outer tube and the inner tube, and the distal ends of the four pull wires are fixed on the circumferential fixing member.

[0015] In some embodiments, the handle portion includes at least four power transmission components, the proximal end of the pull wire is arranged on the power transmission component, the power transmission component is suitable for connecting to a motor, and each pull wire is driven by the power transmission motor to move longitudinally; preferably, the power transmission component is a turntable, and the proximal end of the pull wire is wound on the turntable, and the counterclockwise or clockwise rotation of the turntable drives the pull wire to move longitudinally to the proximal or distal side.

[0016] In some embodiments, a plurality of arched limiting grooves extending longitudinally are formed in the tube wall of the cannula, the plurality of arched limiting grooves are arranged at equal intervals along the tube wall of the cannula, and the pull wire outer tube is embedded in the limiting grooves.

[0017] In some embodiments, the cannula is rotatably disposed on the handle portion; preferably, the handle portion is provided with a rotating portion that can drive the cannula to rotate.

[0018] In some embodiments, the catheter comprises:

[0019] An elongated cannula, the cannula having a proximal end and a distal end, the cannula sequentially comprising a main body section and a distal section along a direction from the proximal end toward the distal end, at least a portion of the distal section being a flexible section;

[0020] A handle portion, wherein the handle portion is connected to the proximal end of the cannula;

[0021] Four pull wires, the four pull wires extend longitudinally and are arranged in the wall of the cannula, the distal ends of the pull wires are fixedly connected to the distal segment, the four pull wires are evenly spaced, the pull wires are controlled by the handle to move longitudinally relative to the main segment, so as to drive the flexible segment to deflect to any direction and any angle, and the direction adjustment steps of the flexible segment include:

[0022] The independent longitudinal movement of the four pull wires drives the four-way deflection of the flexible segment, and the four-way deflection includes leftward deflection, rightward deflection, upward deflection, and downward deflection. The left-right direction is defined as the X-axis, and the up-down direction is defined as the Y-axis. The X-axis passes through the axis of the cannula and intersects the Y-axis perpendicularly. The X-axis and the Y-axis form a two-dimensional coordinate system. The two-dimensional coordinate system divides the XY plane into the first quadrant, the second quadrant, the third quadrant, and the fourth quadrant.

[0023] The longitudinal movement of the same displacement of two adjacent cables drives the flexible segment to deflect in the directions of 45°, 135°, 225°, and 315° in the first quadrant, the second quadrant, the third quadrant, and the fourth quadrant, respectively;

[0024] The longitudinal movement of the two adjacent pull wires with different displacements drives the flexible segment to deflect between the directions of 0-45°, 45°-90°, 90°-135°, 135°-180°, 180°-225°, 225°-270°, 270°-315°, and 315°-360° in the first quadrant, the second quadrant, the third quadrant, and the fourth quadrant, respectively.

[0025] In some embodiments, the travel of the pull wire controls the deflection angle of the flexible section.

[0026] In some embodiments, the catheter is a ureteral sheath, the catheter wall defines a central channel, the handle portion defines an inlet connected to the central channel, a sealing valve is provided at the inlet for sealed entry of instruments, and the handle portion is provided with a negative pressure connector connected to the central channel, and the negative pressure connector is suitable for connection to a negative pressure suction device.

[0027] In some embodiments, the catheter is a ureteral sheath or a visualization catheter.

[0028] The catheter provided by the present invention can achieve deflection and bending in any direction, and can reach the purpose of any angle without rotating the catheter. Compared with the structure of an endoscope, it avoids the use of parts such as snake bones, reduces costs, and the integrated tube body can avoid wrinkles and can enter and exit the human body very smoothly.

[0029] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0031] Figure 1-Figure 4 A schematic diagram of the structure of a unidirectional deflectable catheter provided by the present invention;

[0032] Figure 5-Figure 7 A schematic diagram of the structure of a bidirectionally deflectable catheter provided by the present invention;

[0033] Figure 8-Figure 10 A schematic diagram of the structure of a multi-directional deflectable catheter provided by the present invention;

[0034] Figure 11-13 A schematic diagram of a method for adjusting the direction of a multi-directional deflectable catheter provided by the present invention;

[0035] Figure 14-16 A schematic diagram of the fixing structure of the pull wire and the anchor ring provided by the present invention;

[0036] Fig.17 It is a schematic diagram of the internal structure of the handle part adopted by the present invention;

[0037] Fig.18 for Fig.17 A partial enlarged view of . DETAILED DESCRIPTION

[0038] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "front", "rear", "left", "right", "up", "down", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0039] In the description of the present invention, "proximal end" or "proximal side" refers to the end of the medical device close to the doctor during normal operation, while "distal end" or "distal side" usually refers to the end that first enters the patient's body.

[0040] See also Figure 1 The deflectable catheter provided by the present invention can be used for natural cavity surgery, such as pyelolithotomy for removing stones, and can also be used to remove polyps, tumors, clots, etc. The cannula allows the target object (such as stones, polyps, tumors, clots) to be discharged from the cavity.

[0041] See also Figure 1 The deflectable catheter includes an elongated cannula 1 and a handle portion 2. The elongated cannula 1 is suitable for entering a natural cavity. The cannula 1 has a proximal end and a distal end. The cannula 1 includes a main section 11 and a distal section 12 in sequence from the proximal end to the distal end. At least part of the distal section 12 is a flexible section. The handle portion 2 is connected to the proximal end of the cannula 1. In this way, one or more pull wires can be set in the wall of the cannula 1 to achieve bending deformation of the flexible section. Optionally, the wall of the flexible section includes an outer tube 121, a support layer 122 and an inner tube 123. The support layer 122 is an elastic layer for increasing the compressive strength and flexural strength of the tube body. The support layer includes but is not limited to a spring tube or a braided tube or a sea wave tube. The inner tube is an ultra-thin smooth layer that can effectively reduce the friction of the inner surface. In order to achieve an effective connection between the inner tube and the outer tube material, etching is generally added to the outer surface of the inner tube. The inner tube is generally an etched fluoroplastic tube. In some embodiments, please refer to Figure 2-Figure 4 The distal section 12 is a flexible tube section, the main section 11 is a hard tube section, a pull wire 30 is arranged in the tube wall, the pull wire 30 can slide in the pull wire outer tube 31, the distal end of the pull wire is fixed to the distal section 12, and the handle 2 is used to drive the pull wire 30 to move longitudinally relative to the main section 11, thereby driving the flexible section to deflect. In this way, pulling the pull wire 30 will drive the flexible section to deflect relative to the main section 11, and the deflection direction is upward. In other embodiments, please refer to Figure 5-Figure 7 Two pull wires 30 are symmetrically arranged in the wall of the cannula. Pulling the pull wires drives the flexible segment to deflect upward or downward. When performing renal pelvic surgery, if the target object such as stones, polyps, tumors, coagulated blood clots, etc. is located in other positions, the user adjusts the direction of the cannula head end by frequently rotating the catheter.

[0042] In the embodiment of the present invention, please refer to Figure 8The deflectable catheter includes an elongated cannula 1, a handle portion 2, four pull wires 301, 302, 303, 304, the four pull wires 301, 302, 303, 304 extending longitudinally and arranged in the wall of the cannula 1, the distal ends of the four pull wires 301, 302, 303, 304 are fixedly connected to the distal segment 12, the four pull wires 301, 302, 303, 304 are evenly spaced, and the four pull wires 301, 302, 303, 304 are controlled by the handle portion 2 to move longitudinally relative to the main segment 11 to drive the flexible segment to deflect to any direction and any angle.

[0043] The adjustment method for any direction here is: See Fig.11 , four separate pull wires 301, 302, 303, 304, the independent longitudinal movement of the four pull wires 301, 302, 303, 304 drives the four-way deflection of the flexible segment, and the four-way deflection includes left deflection, right deflection, upward deflection, and downward deflection. The left and right direction is defined here as the X-axis, and the up and down direction is defined as the Y-axis. The X-axis passes through the axis of the cannula and crosses the Y-axis perpendicularly. The X-axis and the Y-axis, the X-axis and the Y-axis constitute a two-dimensional coordinate system. The two-dimensional coordinate system divides the XY plane into the first quadrant A, the second quadrant B, the third quadrant C, and the fourth quadrant D. The measurement range of the first quadrant angle is 0° to 90°, the measurement range of the second quadrant angle is 90° to 180°, the measurement range of the third quadrant angle is 180° to 270°, and the measurement range of the fourth quadrant angle is 270° to 360°

[0044] See also Fig.12 , pull any two cables and apply the same pulling force or the same moving stroke, so as to realize the deflection of the two cables in the corresponding quadrant at 45°; that is, the longitudinal movement of the two adjacent cables with the same moving displacement drives the flexible segment to deflect in the first quadrant A, the second quadrant B, the third quadrant C, and the fourth quadrant D at 45°, 135°, 225°, and 315° respectively;

[0045] See also Fig.13 , pull any two pull wires and apply different pulling forces or different moving strokes, thereby realizing their deflection in any direction within the corresponding quadrant; that is, the longitudinal movement of the two adjacent pull wires with different moving displacements drives the flexible segment to deflect between 0-45°, 45°-90°, 90°-135°, 135°-180°, 180°-225°, 225°-270°, 270°-315°, and 315°-360° in the first quadrant A, the second quadrant B, the third quadrant C, and the fourth quadrant D, respectively. The deflection angle interval here does not include the endpoints. For example, one of the pull wires in the target quadrant area can be pulled first, and then the direction can be adjusted by pulling another adjacent pull wire, or the two pull wires can be pulled at the same time. Adjusting the direction by adjusting the two pull wires at the same time can quickly help the doctor align the head end with the target position.

[0046] As described above, the flexible segment can be deflected in any direction within 360° through the independent or combined movement of the four pull wires 301, 302, 303, and 304. The user can align the flexible segment with any position in the cavity according to the surgical needs without frequently rotating the endoscope or catheter. The use of more than four pull wires allows the head end of the catheter to be independently adjusted in multiple directions. Each pull wire can drive the flexible segment to deflect at different angles, thereby achieving more complex movements, covering a wider range of angles and directions, and meeting the needs for different angles in medical surgery. When dealing with complex surgical cases, such as the need to navigate in narrow or tortuous anatomical structures, the design of at least four pull wires can achieve multi-directional simultaneous operation, allowing the catheter to flexibly respond to different surgical needs and real-time changes, effectively improving the success rate of the operation.

[0047] It is understood that in order to achieve smooth longitudinal movement of the pull wire, please refer to Figure 8 , the inner wall of the cannula 1 is fixed with a pull wire outer tube 311, 312, 313, 314, the pull wires 301, 302, 303, 304 are longitudinally extended in the pull wire outer tubes 311, 312, 313, 314, and the proximal ends of the pull wires 301, 302, 303, 304 are controlled by the handle 2. In this embodiment, four pull wire outer tubes 311, 312, 313, 314 are arranged in the inner wall of the cannula 1, the pull wires 301, 302, 303, 304 penetrate the pull wire outer tubes 311, 312, 313, 314, and the pull wires 301, 302, 303, 304 slide in the pull wire outer tubes 311, 312, 313, 314 when the pull wires 301, 302, 303, 304 are pulled.

[0048] After the direction of the flexible segment is adjusted by the pull wire, the deflection angle of the flexible segment is controlled by adjusting the moving stroke of the pull wire.

[0049] To better adjust the direction of the flexible segment, please refer to Figure 2 , the distal segment 12 includes a flexible segment and a head end 13 from the proximal end to the distal end, that is, the flexible segment is attached between the head end 13 and the main segment 11, the head end 13 is connected to the proximal end of the flexible segment, and the distal ends of the pull wires 301, 302, 303, and 304 are connected to the distal end of the flexible segment or the head end 13. In some examples, the pull wires 301, 302, 303, and 304 can be fixed at any node of the flexible segment, or can be fixed at the distal end adjacent to the flexible segment, that is, the deflection of the flexible segment can be achieved.

[0050] In this embodiment, the pull wires 301, 302, 303, 304 are connected to the cannula head end 13. Pulling the pull wires 301, 302, 303, 304 drives the deflection of the flexible segments, and the flexible segments drive the natural deflection of the head end 13. As mentioned above, in order to achieve the discharge of the target object, the head end is set as a functional head end, for example, it is provided with an infusion port, a suction port, a laser port and a camera, etc. The head end is formed to be rigid and difficult to bend and deform. At this time, the head end drives the functional head end to deflect to the target position by means of the deflection of the flexible segment to perform liquid infusion, suction, laser lithotripsy and visual operation.

[0051] To facilitate the distal fixation of the pull wires 301, 302, 303, 304, see Figure 14-16 , the head end 13 has a circumferential fixing member 6, and the pull wires 301, 302, 303, and 304 are fixedly connected to the circumferential fixing member 6 at circumferential intervals. In some embodiments, the head end 13 includes a tube body and a circumferential fixing member 6 arranged in the tube body. In this embodiment, the specific implementation means of the circumferential fixing member 6 is an anchoring ring, and the head end 13 includes an outer tube, an anchoring ring, and an inner tube. The anchoring ring is arranged between the outer tube and the inner tube, and the distal ends of the four pull wires 301, 302, 303, and 304 are fixed to the circumferential fixing member 6. Exemplarily, the pull wires 301, 302, 303, and 304 are fixedly connected to the anchoring ring by laser welding, soldering, or crimping. It ensures that the direction of the pull wires 301, 302, 303, and 304 after being fixed will not be significantly deflected, and it also has the effect of strengthening the directionality of the pull wires during the tube body forming process.

[0052] In this embodiment, please refer to Figure 1 , the main body section 11 is a rigid tube section. And the hardness of the rigid tube section is not consistent. In some specific examples, the rigid tube section includes a first tube section and a second tube section, the second tube section is located at the distal end of the first tube section, the hardness of the second tube section is between the first tube section and the flexible segment, and it is attached between the first tube section and the flexible segment. When the flexible segment is deflected, the gradual change of the hardness design prolongs the service life of the catheter. The tube wall of the flexible segment includes an outer tube 121, a support layer 122 and an inner tube 123, and the pull wires 301, 302, 303, and 304 are all arranged in any interior of the outer tube 121, the support layer 122 and the inner tube 123 or in the gap therebetween; in this embodiment, please refer to Figure 8 and Fig. 9 The pull wires 301 , 302 , 303 , and 304 are all arranged inside the inner tube 121 .

[0053] For further information, see Fig.17The handle portion 2 includes four power transmission parts 71, 72, 73, 74, and the proximal ends of the pull wires 301, 302, 303, 304 are arranged on the power transmission parts 71, 72, 73, 74. The power transmission parts 71, 72, 73, 74 are suitable for connecting with a motor, and each pull wire 301, 302, 303, 304 is driven by the power transmission machine to move longitudinally. Exemplarily, the power transmission part is a turntable, and the proximal end of the pull wire is wound on the turntable. The counterclockwise or clockwise rotation of the turntable drives the pull wire to move longitudinally toward the proximal or distal side. The four pull wires are controlled by separate motors respectively. Each separate pull wire is connected by a turntable inside the handle portion of the catheter. The turntable is connected to the corresponding matching part on the device, and the power of the motor on the device is transmitted to the turntable, and then transmitted to the bending angle of the catheter head end through the pull wire.

[0054] By controlling a single pull wire with a single motor, the bending can be adjusted in 4 directions. By controlling two adjacent pull wires with the same force, the bending can be adjusted in 8 directions. If two adjacent motors use different forces to control two adjacent pull wires, the angle can be precisely controlled through precise force control. The bending in 8 directions can be adjusted in all directions, and finally any angle can be reached without rotation. The operation of the handle becomes simpler and more user-friendly. The doctor can achieve a variety of deflection methods through different pull wire combinations, which reduces hand fatigue and improves the comfort of operation and the convenience of control.

[0055] See also Fig. 9 A plurality of arched limiting grooves 5 extending in the longitudinal direction are formed in the wall of the cannula 1, and the plurality of limiting grooves 5 are arranged at equal intervals along the wall of the cannula 1. The pull wire outer tubes 311, 312, 313, 314 are embedded in the limiting grooves 5, that is, the pull wire outer tubes 311, 312, 313, 314 can be confined in the arched limiting grooves 5. Compared with the circular cavity, it can avoid the deviation of the pull wire outer tube during the processing process, avoid the overall confusion in the four directions caused by the deviation of the pull wire angle, and then ensure the equidistant distribution of the four pull wires, ensuring the accuracy of the direction adjustment. Through the evenly distributed pull wires, the movement of the catheter can be controlled more accurately, reducing the shaking or error during the deflection process.

[0056] According to the technical concept of the present invention, those skilled in the art can design a variety of pull wires to achieve more flexible direction adjustment according to the design concept of the four pull wires provided in the embodiment, for example, 6 pull wires are set. Two adjacent pull wires may have similar functions, but they are coordinated to achieve more detailed direction control, and a more complex handle part can be designed, including more power transmission parts (such as motors, turntables, etc.). Each motor controls one or two pull wires, or one motor controls multiple pull wires through a transmission mechanism to achieve complex deflection angles through the control of individual or combined pull wires. For example, any two adjacent pull wires can be operated with different or the same pulling force at the same time to achieve fine direction adjustment.

[0057] In some application scenarios, see Figure 1 The catheter is a ureteral sheath, the wall of the cannula 1 defines a central channel, the handle 2 defines an inlet connected to the central channel, a sealing valve is provided at the inlet for sealed entry of instruments, and the handle 2 is provided with a negative pressure connector connected to the central channel, which is suitable for connection with a negative pressure suction device. In other application scenarios, please refer to Fig.17 and Fig.18 The catheter is a visual catheter, which is similar to the function of an endoscope. The catheter is provided with an instrument channel, a drainage channel, and a suction channel. Correspondingly, the head end of the catheter includes an infusion port, a suction port, a camera, etc. The handle portion 2 includes a handle portion shell 21, an infusion joint 33, a negative pressure joint 34, and an instrument inlet 32 ​​arranged on the handle portion shell 21; the suction channel is separated from the drainage channel and the instrument channel, the suction channel is connected to the negative pressure joint 34, the drainage channel is connected to the infusion joint 33, and the instrument channel is connected to the instrument interface 32. A camera is arranged at the head end of the insertion tube to facilitate the doctor to understand the situation of the target cavity. The instrument channel is used for external instruments such as laser beams to pass through and reach the head end to crush stones in the renal pelvis or cut tissues, etc. The liquid is injected into the body cavity through the drainage channel, and the liquid in the cavity with stones or tissues is sucked out of the body through the suction channel.

[0058] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0059] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A multi-directionally deflectable catheter, characterized in that: The catheter includes: An elongated cannula, the cannula having a proximal end and a distal end, the cannula sequentially comprising a main body section and a distal section along a direction from the proximal end toward the distal end, at least a portion of the distal section being a flexible section; A handle portion, wherein the handle portion is connected to the proximal end of the cannula; At least four pull wires extend longitudinally and are arranged in the wall of the cannula. The distal ends of the pull wires are fixedly connected to the distal segment. The at least four pull wires are evenly spaced. The pull wires are controlled by the handle to move longitudinally relative to the main segment to drive the flexible segment to deflect to any direction and any angle.

2. The catheter according to claim 1, characterized in that The distal section includes a flexible segment and a head end from the proximal end toward the distal end. The head end is connected to the distal end of the flexible segment, and the distal end of the pull wire is connected to the distal end or the head end of the flexible segment.

3. The catheter according to claim 1, characterized in that A pull wire outer tube is fixedly arranged inside the tube wall of the cannula, the pull wire extends longitudinally inside the pull wire outer tube, and the proximal end of the pull wire is controlled by the handle.

4. The catheter according to claim 2, characterized in that The head end is provided with a circumferential fixing piece, and at least four pull wires are fixedly connected to the circumferential fixing piece at circumferential intervals.

5. The catheter according to claim 2, characterized in that The main body section is a rigid pipe section.

6. The catheter according to claim 1, characterized in that The tube wall of the flexible segment includes an outer tube, a support layer and an inner tube. The support layer is formed between the outer tube and the inner tube layer. The pull wires are arranged inside or in the gap between the outer tube, the support layer and the inner tube.

7. The catheter according to claim 6, characterized in that The supporting layer is an elastic layer.

8. The catheter according to claim 2, characterized in that The head end comprises an outer tube, a circumferential fixing piece and an inner tube, the circumferential fixing piece is arranged between the outer tube and the inner tube, and the distal ends of the four pulling wires are fixed on the circumferential fixing piece.

9. The catheter according to claim 1, characterized in that The handle portion includes at least four power transmission components. The proximal ends of the pull wires are arranged on the power transmission components. The power transmission components are suitable for connecting with a motor. Each pull wire is driven by the power transmission components to move longitudinally.

10. The catheter according to claim 3, characterized in that A plurality of arched limiting grooves extending in the longitudinal direction are formed in the tube wall of the insert tube, and the plurality of arched limiting grooves are arranged at equal intervals along the tube wall of the insert tube, and the pull wire outer tube is embedded in the limiting grooves.

11. The catheter according to claim 1, characterized in that The catheter includes: An elongated cannula, the cannula having a proximal end and a distal end, the cannula sequentially comprising a main body section and a distal section along a direction from the proximal end toward the distal end, at least a portion of the distal section being a flexible section; A handle portion, wherein the handle portion is connected to the proximal end of the cannula; Four pull wires, the four pull wires extend longitudinally and are arranged in the wall of the cannula, the distal ends of the pull wires are fixedly connected to the distal segment, the four pull wires are evenly spaced, the pull wires are controlled by the handle to move longitudinally relative to the main segment, so as to drive the flexible segment to deflect to any direction and any angle, and the direction adjustment steps of the flexible segment include: The independent longitudinal movement of the four pull wires drives the four-way deflection of the flexible segment, and the four-way deflection includes leftward deflection, rightward deflection, upward deflection, and downward deflection. The left-right direction is defined as the X-axis, and the up-down direction is defined as the Y-axis. The X-axis passes through the axis of the cannula and intersects the Y-axis perpendicularly. The X-axis and the Y-axis form a two-dimensional coordinate system. The two-dimensional coordinate system divides the XY plane into the first quadrant, the second quadrant, the third quadrant, and the fourth quadrant. The longitudinal movement of the same displacement of two adjacent cables drives the flexible segment to deflect in the directions of 45°, 135°, 225°, and 315° in the first quadrant, the second quadrant, the third quadrant, and the fourth quadrant, respectively; The longitudinal movement of the two adjacent pull wires with different displacements drives the flexible segment to deflect between the directions of 0-45°, 45°-90°, 90°-135°, 135°-180°, 180°-225°, 225°-270°, 270°-315°, and 315°-360° in the first quadrant, the second quadrant, the third quadrant, and the fourth quadrant, respectively.

12. The multi-directionally deflectable catheter according to claim 11, characterized in that: The travel of the pull wire controls the deflection angle of the flexible segment.

13. The multi-directionally deflectable catheter according to claim 1, characterized in that: The catheter is a ureteral sheath or a visual catheter.

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