Bending control assembly and conveying system
By using the pull wire in the bending control assembly of the conveying system to undergo reversible tensile deformation when the preset tensile stress is reached, the problem of poor bending stability of the bending pipe fitting during torsion is solved, and better torque control performance is achieved.
Patent Information
- Application Number
- CN202311484891.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-08
- Publication Date
- 2025-05-09
AI Technical Summary
During the torsion process of existing conveyor systems, the bending shape of the bend control pipe fittings is poor, resulting in poor torque control performance.
A bending control assembly is designed, including an external bending conduit and an internal bending conduit. The reversible tensile deformation occurs when the preset tensile stress is reached through the pulling wire, which compensates for the stroke changes during the torsion of the bending pipe fittings, and maintains the constant tensile force and bending shape of the internal bending conduit.
Through the reversible tensile deformation of the pulling wire, the bending stability of the bending pipe fittings during the torsion process is achieved, the torque control performance is improved, and the bending changes are avoided.
Smart Images
Figure CN119950116A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of medical devices, and in particular to a bending control component and a delivery system. Background Art
[0002] Diseased or defective heart valves can be repaired or replaced by implanting artificial implants, such as prosthetic heart valves or repair clips. The artificial implant is loaded at the distal end of the delivery system, which is delivered to the surgical site and released by the delivery system to replace the native valve ring. Taking transcatheter mitral valve replacement or repair surgery as an example, in transcatheter mitral valve replacement or repair surgery via the femoral route, the doctor perforates the atrial septum between the right atrium and the left atrium of the patient's heart to form a channel. The doctor then inserts surgical tools through this channel and enters the left atrium to repair or replace the mitral valve. Compared with traditional open-chest surgery, transseptal mitral valve surgery is a more minimally invasive surgical method that can reduce surgical trauma and postoperative pain, shorten recovery time, and preserve heart integrity. This surgical method has greater advantages for some high-risk patients with heart disease, especially the elderly and other patients with other health problems.
[0003] In the process of using a delivery system to deliver an artificial implant to the target site, the delivery system usually requires two sections of bending control and multi-plane bending control because the delivery path is relatively complex, the delivery path is long, and it needs to adapt to the complex cardiac anatomical structure. Usually these positioning functions are realized by two bending control tubes. Specifically, the outer bending control tube is responsible for the active bending control of the proximal bending control section; the inner bending control tube is responsible for the active bending control of the distal bending control section, as well as the torsion of the distal bending control plane.
[0004] In the related art, the delivery system uses a pull wire to transmit the proximal control force to the distal adjustable bend. After the internal catheter is bent, its abdominal pull wire is in a tensioned state. When the torsion begins, the pull wire cavity first moves along the annular direction with the catheter, and then the pull wire cavity squeezes the pull wire and forces it to move. When the pull wire is forced to twist from the abdomen of the catheter to the side, its length tends to become longer. At this time, the pull wire is in a tensioned state, and the distal end is fixedly connected and locked after the proximal bending is completed. In order to achieve torsion, the catheter must overcome the tension of the pull wire and cause the pull wire to deform elastically to compensate for the difference in length at different positions. Or when the torsion is not enough to overcome the tension of the pull wire, the catheter will compensate for the stroke difference of the pull wire in the form of axial contraction. In this way, the tension on the pull wire that is forced to stretch during the torsion process further increases, resulting in a further increase in the torsion control resistance, and the control angle of the catheter also increases with the tension. Therefore, during the torsion control process, the stability of the bend is also poor. Summary of the invention
[0005] Based on this, a bending control assembly and a conveying system are provided to solve the problem of poor torque control performance.
[0006] On the one hand, the present application provides a control bending assembly, including a control bending tube and a pull wire, the control bending tube including an outer control bending catheter and an inner control bending catheter extending from the distal end of the outer control bending catheter, the outer control bending catheter can drive the inner control bending catheter to bend in a first plane, the pull wire can pull the inner control bending catheter to bend in a second plane relative to the distal end of the outer control bending catheter, the second plane intersects with the first plane, when the tensile stress of the pull wire reaches a preset value, the stiffness of the pull wire decreases and reversible tensile deformation occurs to compensate for the change in the stroke of the pull wire during the torsion of the control bending tube.
[0007] In one embodiment, all or part of the pull wire is made of superelastic material.
[0008] In one embodiment, the bending control assembly further includes an adjusting mechanism, which is connected to the pull wire and is used to adjust the tensile deformation of the pull wire so that the pull wire applies a preset constant tension to the inner bending control catheter.
[0009] In one embodiment, the adjustment mechanism includes a shell, a sliding member and a traction member, the proximal end of the inner control bend catheter is connected to the shell, the sliding member is arranged in the shell and can move along the axial direction of the inner control bend catheter; the pull wire includes a first pull wire and a second pull wire, the stiffness of the first pull wire is greater than the stiffness of the second pull wire, the material of the second pull wire is a superelastic material, the distal end of the first pull wire is connected to the distal end of the inner control bend catheter, the proximal end of the first pull wire is connected to the distal end of the second pull wire through the sliding member, the proximal end of the second pull wire is connected to the traction member, and the traction force is transmitted to the first pull wire through the sliding member under the traction of the traction member, and the sliding member can adjust the angle between the traction direction of the second pull wire on the sliding member and the traction direction of the sliding member on the first pull wire when moving along the axial direction of the inner control bend catheter.
[0010] In one embodiment, the adjustment mechanism also includes a guide member, which is movably disposed between the sliding member and the traction member, and the second pull wire is in smooth contact with the guide member and is tensioned between the sliding member and the traction member. When the guide member approaches the sliding member along the axial direction of the bending control tube, the second pull wire, under the guidance of the guide member, increases the angle between the traction direction of the second pull wire on the sliding member and the traction direction of the sliding member on the first pull wire.
[0011] In one embodiment, the adjustment mechanism further includes a fixing rod, the inner control bend guide tube is connected to the fixing rod, and the sliding member, the guiding member and the pulling member are all slidably mounted on the fixing rod.
[0012] In one embodiment, the sliding member is provided with a first connecting portion and a second connecting portion, the proximal end of the first pull wire is connected to the first connecting portion, and the second pull wire is connected to the second connecting portion.
[0013] In one embodiment, the guide member is provided with a pin, and the pin is in smooth contact with the second pull wire.
[0014] In one embodiment, the traction member is provided with a third connection portion, and the proximal end of the second pull wire is connected to the third connection portion.
[0015] In one embodiment, the adjustment mechanism also includes a knob, a first threaded sleeve and a second threaded sleeve, the knob is rotatably connected to the shell, the knob is connected to the first threaded sleeve and is used to drive the first threaded sleeve to rotate around the fixed rod in the shell, the second threaded sleeve is arranged between the fixed rod and the first threaded sleeve, the second threaded sleeve is threadedly matched with the first threaded sleeve, and the second threaded sleeve is circumferentially limited to the fixed rod, so that when the knob drives the first threaded sleeve to rotate, the second threaded sleeve moves along the axial direction of the fixed rod, and the traction member is linked to the second threaded sleeve.
[0016] On the other hand, the present application provides a conveying system, including a catheter and a bending control assembly as described above, wherein the catheter and the bending control tube are arranged in a socket-type arrangement, and the bending control assembly is used to drive the catheter to bend when bending occurs, so as to adjust the bending direction and bending angle of the catheter.
[0017] The above-mentioned bending control assembly and conveying system, the bending control assembly includes a bending control pipe and a pull wire, the bending control pipe includes an outer bending control tube and an inner bending control tube extending from the distal end of the outer bending control tube, the outer bending control tube can drive the inner bending control tube to bend in a first plane, the pull wire can pull the inner bending control tube to bend in a second plane relative to the distal end of the outer bending control tube, the second plane intersects with the first plane, thereby realizing torsion in multiple dimensions. In addition, in the bending control assembly, when the tensile stress of the pull wire reaches a preset value, the stiffness of the pull wire decreases and reversible tensile deformation occurs, so as to use the tensile deformation of the pull wire itself to compensate for the change in the travel of the pull wire during the torsion of the bending control pipe, so that the pulling force of the pull wire on the inner bending control tube is constant, so as to maintain the bending control angle of the inner bending control tube, thereby avoiding the change of the bending type during torsion and improving the torsion control performance. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, drawings of other embodiments can be obtained based on these drawings without paying any creative work.
[0019] Figure 1 This is a schematic structural diagram of a bending control pipe in a bending control assembly of a conveying system according to one embodiment of the present application.
[0020] Figure 2 It is a schematic diagram of the structure of the adjustment mechanism in the bending control assembly of the conveying system according to one embodiment.
[0021] Figure 3 This is a schematic diagram of the stress-strain curve of NiTi material when the superelastic material used for the pull wire in the bending control assembly of the conveying system according to one embodiment is NiTi material.
[0022] Figure 4 This is a schematic diagram of adjusting the angles of the first pull wire and the second pull wire in a bending control assembly of a conveying system according to one embodiment.
[0023] Reference numerals:
[0024] A. External control bend catheter; B. Internal control bend catheter; C. Inner tube; 1. Knob; 2. Shell; 3. First pull wire; 4. Second pull wire; 5. First connecting part; 6. Second connecting part; 7. Pin; 8. First screw; 9. Second screw; 10. Sliding member; 11. Guide member; 12. Pulling member; 13. Fixed rod; 14. First threaded sleeve; 15. Second threaded sleeve. DETAILED DESCRIPTION
[0025] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.
[0026] In the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0027] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0028] It should be noted that "distal" and "proximal" are used as directional terms, which are commonly used terms in the field of interventional medical devices, where "distal" refers to the end away from the operator (such as the doctor) during the operation, and "proximal" refers to the end close to the operator during the operation. Axial refers to the direction in which the central axis of the medical device extends; radial refers to the direction perpendicular to the above-mentioned axial direction; circumferential refers to the direction around the above-mentioned axial direction.
[0029] The present application provides a delivery system, comprising a catheter and a bending control assembly, wherein the catheter and the bending control pipe are sleeved with each other. The bending control assembly is used to drive the catheter to bend when bending occurs, so as to adjust the bending direction and bending angle of the catheter, so that the catheter can adapt to delivering the implant to a suitable position for release.
[0030] For ease of understanding, the following Figure 1 and Figure 2 As shown, taking the catheter including the inner tube C as an example, the structure of the delivery system is further explained.
[0031] The control bending assembly of the conveying system includes a control bending pipe and a pull wire. The control bending pipe includes an outer control bending catheter A and an inner control bending catheter B extending from the distal end of the outer control bending catheter A. In this embodiment, the inner control bending catheter B can be sleeved outside the inner tube C. The outer control bending catheter A can drive the inner control bending catheter B to bend in the first plane, and the pull wire can pull the inner control bending catheter B to bend in the second plane relative to the distal end of the outer control bending catheter A, and the second plane intersects with the first plane. In this way, the inner control bending catheter B and the outer control bending catheter A can be used to realize the bending of the control bending pipe as a whole in different directions in three-dimensional space. It should be noted here that the first surface and the second surface are only to illustrate that the control bending pipe can realize secondary bending in different directions, and are not limited to the outer control bending catheter A can only bend in the first plane, nor are they limited to the inner control bending catheter B relative to the distal end of the outer control bending catheter A can only bend in the second plane. In actual operation, the outer control bend catheter A can be pulled first to make the outer control bend catheter A and the inner control bend catheter B bend in the first plane; then, the inner control bend catheter B is pulled to bend in different directions, that is, the inner control bend catheter B is bent in the direction away from the first plane. Therefore, the second plane where the inner control bend catheter B is bent intersects with the aforementioned first plane, which means that the control bend pipe can realize bending in different directions in three-dimensional space.
[0032] In the implementation of the present application, the stiffness of the pull wire will change under certain conditions. Specifically, when the tensile stress of the pull wire reaches a preset value, the stiffness of the pull wire decreases and a reversible tensile deformation occurs to compensate for the change in the travel of the pull wire during the torsion of the control bending pipe, so that the pulling force of the pull wire on the inner control bending conduit B is constant.
[0033] In the above embodiment, the tensile deformation of the cable itself is used to compensate for the change in the travel of the cable during the torsion of the control bending pipe, so that the tension of the cable on the inner control bending pipe B is constant. Therefore, when the inner control bending pipe B is bending with the outer control bending pipe A, even if the cable has a travel difference due to the torsion of the outer control bending pipe A, the stability of the bending control of the inner control bending pipe B by the cable can be maintained, thereby improving the torsion control performance of the control bending assembly.
[0034] In the embodiments of the present application, the pull wire only needs to reduce stiffness and undergo reversible tensile deformation when the tensile stress reaches a preset value. For example, in some embodiments, all or part of the pull wire is made of superelastic material. Superelastic materials include but are not limited to nickel-titanium alloys.
[0035] For ease of understanding, the following explanation is given by taking the example of the superelastic material used for the pull wire being nickel-titanium alloy.
[0036] Combination Figure 3 As shown in the stress-strain curve of NiTi material, when the material undergoes phase change, the strain and stress are not in a linear relationship. Figure 3In the interval corresponding to the horizontal section of the strain curve (stress interval is 400MPa-600MPa), the strain increases while the stress remains basically unchanged. Figure 3 Taking the stress-strain curve of the NiTi material shown as an example, when the strain is in the interval corresponding to 1% to 6%, the tensile deformation can be calculated as follows: 100mm×(6%-1%)=5mm when a 100mm long NiTi wire is tested, and the tensile length is about 5mm when the tensile test is performed at 400MPa-600MPa. Assuming that the wire tension during torsion is 69N, and the stroke of the wire increases by 5mm when it turns from the belly of the inner control bend catheter B to the side, it just matches the tensile tension and tensile deformation in the interval corresponding to the above-mentioned horizontal section. At this time, when the inner control bend is twisted, the wire will be stretched 5mm without resistance, thereby compensating for the stroke of the wire during torsion. Of course, by adjusting the diameter and length of the NiTi wire, it can be matched with the wire tension and stroke changes when the inner control bend catheter B is twisted.
[0037] In some embodiments, the bending control assembly further includes an adjustment mechanism, which is connected to the pull wire and is used to adjust the tensile deformation of the pull wire so that the pull wire applies a preset constant tension to the inner bending control conduit B. In other words, the tensile deformation of the pull wire can be adjusted by the adjustment mechanism. Since the tensile deformation is used to compensate for the change in the travel of the pull wire during the torsion of the bending control pipe, the adjustment mechanism can adjust the constant tension applied by the pull wire to reach the preset constant tension, so that the bending control pipe can be stably maintained in different bending shapes. It can be understood that after the adjustment mechanism adjusts the tension applied by the pull wire to the inner bending control conduit B according to the bending shape of the bending control pipe, the adjustment mechanism stops adjusting the pull wire so that the pull wire remains in the state.
[0038] In the bending control assembly of the above embodiment, the tensile deformation of the wire is adjusted by the adjusting mechanism, so that the tensile deformation of the wire produced during the bending control process matches the stroke change produced by the torsion of the wire under the corresponding bending shape of the corresponding bending control conduit, so that the tension of the wire acting on the inner bending control conduit B is constant, and the bending shape of the inner bending control conduit B is maintained. Specifically, in the bending control assembly of the present application, the stress level of the wire in the torsion state can be adjusted to be consistent with the phase change stress of the superelastic material by the adjusting mechanism, so that when torsion occurs, the stress on the wire reaches the phase change stress of the material, the material changes from austenite to martensite, the stiffness drops sharply, and the wire is stretched to compensate for the change in the wire stroke.
[0039] See again Figure 2As shown, the adjustment mechanism includes a housing 2, a sliding member 10 and a traction member 12. The proximal end of the inner control bend catheter B is connected to the housing 2, and the sliding member 10 is arranged in the housing 2 and can move along the axial direction of the inner control bend catheter B. The pull wire includes a first pull wire 3 and a second pull wire 4, wherein the stiffness of the first pull wire 3 is greater than the stiffness of the second pull wire 4, and the material of the second pull wire 4 is a superelastic material. In some embodiments, the material of the first pull wire 3 can be a stainless steel material, a copper alloy material or a carbon fiber material. The material of the second pull wire 4 can be a nickel-titanium alloy material, and the materials of the first pull wire 3 and the second pull wire 4 are not limited here. The distal end of the first pull wire 3 is connected to the distal end of the inner control bend catheter B, and the proximal end of the first pull wire 3 is connected to the distal end of the second pull wire 4 through the sliding member 10, and the proximal end of the second pull wire 4 is connected to the traction member 12, and the traction force is transmitted to the first pull wire 3 through the sliding member 10 under the traction of the traction member 12. In this embodiment, when the sliding member 10 moves axially along the inner control bend catheter B, it is able to adjust the angle between the direction of the traction force of the second pull wire 4 on the sliding member 10 and the direction of the traction force of the sliding member 10 on the first pull wire 3, so that the pulling force of the second pull wire 4 on the first pull wire 3 through the sliding member 10 can meet the need of the first pull wire 3 to keep the inner control bend catheter B in a predetermined bend shape.
[0040] Continue reading Figure 2 As shown, in some embodiments, the adjustment mechanism further includes a guide member 11, which is movably disposed between the sliding member 10 and the traction member 12, and the second pull wire 4 is in smooth contact with the guide member 11 and is tensioned between the sliding member 10 and the traction member 12. When the guide member 11 approaches the sliding member 10 along the axial direction of the bending control pipe, the second pull wire 4, under the guidance of the guide member 11, increases the angle between the traction direction of the second pull wire 4 on the sliding member 10 and the traction direction of the sliding member 10 on the first pull wire 3.
[0041] Furthermore, the adjustment mechanism further includes a fixed rod 13, the inner control bend conduit B is connected to the fixed rod 13, and the sliding member 10, the guide member 11 and the traction member 12 are all slidably sleeved on the fixed rod 13. In this way, the fixed rod 13 can maintain the movement stability of the sliding member 10, the guide member 11 and the traction member 12.
[0042] In some embodiments, the sliding member 10 is provided with a first connection portion 5 and a second connection portion 6. The proximal end of the first pull wire 3 is connected to the first connection portion 5, and the second pull wire 4 is connected to the second connection portion 6. The second pull wire 4 and the second connection portion 6 can be connected by a screw or a locking member to improve the connection stability between the two.
[0043] In some embodiments, the guide 11 is provided with a pin 7, and the pin 7 is in smooth contact with the second pull wire 4. It should be noted here that in the embodiment of the present application, smooth contact refers to the two objects maintaining contact and the friction between each other is so small that it can be ignored. Specifically, the surface of the pin 7 is a smooth surface, thereby reducing the friction resistance when the second pull wire 4 moves relative to the pin 7, making the adjustment process smoother, and also reducing the probability of the second pull wire 4 wearing.
[0044] In some embodiments, the traction member 12 is provided with a third connection portion, and the proximal end of the second pull wire 4 is connected to the third connection portion. The proximal end of the second pull wire 4 can be connected to the third connection portion by a screw or a locking member. Exemplarily, the proximal end of the second pull wire 4 is connected to the third connection portion by a first screw 8 and a second screw 9, thereby utilizing the first screw 8 and the second screw 9 to enhance the connection stability. It should be noted that the number of screws is not limited to 2, and can be specifically 1 or 3, which is not limited here.
[0045] In some embodiments, the adjustment mechanism further includes a knob 1, a first threaded sleeve 14, and a second threaded sleeve 15. The knob 1 is rotatably connected to the housing 2, and the knob 1 is connected to the first threaded sleeve 14, and is used to drive the first threaded sleeve 14 to rotate around the fixed rod 13 in the housing 2. The second threaded sleeve 15 is arranged between the fixed rod 13 and the first threaded sleeve 14, and the second threaded sleeve 15 is threadedly matched with the first threaded sleeve 14. Among them, the first threaded sleeve 14 has an internal thread, and the second threaded sleeve 15 has an external thread that matches the internal thread, so that the first threaded sleeve 14 and the second threaded sleeve 15 are threadedly matched, so that when the first threaded sleeve 14 rotates, the second threaded sleeve 15 will be threadedly driven to move axially.
[0046] It should be noted that, in this embodiment, the second threaded sleeve 15 is circumferentially limited to the fixed rod 13, so that when the knob 1 drives the first threaded sleeve 14 to rotate, the second threaded sleeve 15 moves along the axial direction of the fixed rod 13. The traction member 12 is arranged in linkage with the second threaded sleeve 15, so that the second threaded sleeve 15 drives the traction member 12 to move along the fixed rod 13, so that the traction member 12 pulls the second pull wire 4.
[0047] For ease of understanding, the following takes the implementation of the pull wire including the first pull wire 3 and the second pull wire 4 as an example to illustrate the principle of the bending control assembly of the present application to enhance the stability of the bending shape to improve the torsion control performance.
[0048] Combination Figure 2 and Figure 4As shown, the angle between the first pull wire 3 and the axis of the inner control bend catheter B is very small, and it can be approximately considered that the first pull wire 3 is parallel to the axis of the inner control bend catheter B. The angle θ between the second pull wire 4 and the axis of the inner control bend catheter B is relatively large, and the axial position of the guide 11 can be adjusted so that the second pull wire 4 between the pin 7 and the sliding member 10 is at different angles to the axis of the inner control bend catheter B, thereby adjusting the size of the angle θ. By adjusting the distance between the traction member 12 and the sliding member 10, the total length L of the second pull wire 4 can be adjusted. It can be understood that, as Figure 4 As shown, when the angle θ is 0 degrees, the tension value on the first pull wire 3 is equal to the tension value on the second pull wire 4. When the angle θ is 60 degrees, the tension value on the first pull wire 3 is equal to 1 / 2 of the tension value on the second pull wire 4. It can be seen that by adjusting the angle θ, the fixed nickel-titanium phase change stress can be matched with the variable stress of the pull wire during torsion.
[0049] Specifically, for a certain anatomical morphology and surgery, the bend shape of the internal control bend catheter B during twisting is determined. For the internal control bend catheter B based on a certain material and model, when determining the bend shape during twisting, that is, under the corresponding bend shape, the pulling force f required for the first pull wire 3 is also determined. Therefore, by adjusting θ, f can be amplified to the force value F=f / cosθ required for the second pull wire 4 to undergo a phase change. Similarly, for a certain anatomical morphology and surgery, the twisting angle of the internal control bend catheter B is also determined, and then the required pull wire stroke difference is also determined. In this way, the present application utilizes an adjustment mechanism to adjust the total length L of the second pull wire 4 to achieve stroke compensation.
[0050] Since the second pull wire 4 can achieve stroke compensation, the tension of the pull wire in the torsion stage is kept at a constant value. Therefore, the bending control angle of the inner control bending catheter B will not change, thereby solving the problem of poor torsion control performance due to bending shape changes during torsion.
[0051] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0052] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the inventive concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.
Claims
1. A bending control assembly, characterized in that: It includes a control bending pipe fitting and a pulling wire, wherein the control bending pipe fitting includes an outer control bending catheter and an inner control bending catheter extending from the distal end of the outer control bending catheter, the outer control bending catheter can drive the inner control bending catheter to bend in a first plane, the pulling wire can pull the inner control bending catheter to bend in a second plane relative to the distal end of the outer control bending catheter, the second plane intersects with the first plane, and when the tensile stress of the pulling wire reaches a preset value, the stiffness of the pulling wire decreases and reversible tensile deformation occurs to compensate for the change in the stroke of the pulling wire during the torsion of the control bending pipe fitting.
2. The bending control assembly according to claim 1, characterized in that: All or part of the material of the pull wire is super elastic material.
3. The bending control assembly according to claim 1, characterized in that: It also includes an adjusting mechanism, which is connected to the pull wire and is used to adjust the tensile deformation of the pull wire so that the pull wire applies a preset constant pulling force to the inner control bend catheter.
4. The bending control assembly according to claim 3, characterized in that: The adjustment mechanism includes a shell, a sliding member and a traction member, the proximal end of the inner control bend catheter is connected to the shell, the sliding member is arranged in the shell and can move along the axial direction of the inner control bend catheter; the pull wire includes a first pull wire and a second pull wire, the stiffness of the first pull wire is greater than the stiffness of the second pull wire, the material of the second pull wire is a superelastic material, the distal end of the first pull wire is connected to the distal end of the inner control bend catheter, the proximal end of the first pull wire is connected to the distal end of the second pull wire through the sliding member, the proximal end of the second pull wire is connected to the traction member, and the traction force is transmitted to the first pull wire through the sliding member under the traction of the traction member, and the sliding member can adjust the angle between the traction direction of the second pull wire on the sliding member and the traction direction of the sliding member on the first pull wire when moving along the axial direction of the inner control bend catheter.
5. The bending control assembly according to claim 4, characterized in that: The adjustment mechanism also includes a guide member, which is movably arranged between the sliding member and the traction member, and the second pull wire is in smooth contact with the guide member and is tensioned between the sliding member and the traction member. When the guide member approaches the sliding member along the axial direction of the bending control pipe, the second pull wire, under the guidance of the guide member, increases the angle between the traction direction of the second pull wire on the sliding member and the traction direction of the sliding member on the first pull wire.
6. The bending control assembly according to claim 5, characterized in that: The adjustment mechanism also includes a fixing rod, the inner control bend guide tube is connected to the fixing rod, and the sliding member, the guiding member and the pulling member are all slidably sleeved on the fixing rod.
7. The bending control assembly according to claim 6, characterized in that: The sliding member is provided with a first connecting portion and a second connecting portion, the proximal end of the first pull wire is connected to the first connecting portion, and the second pull wire is connected to the second connecting portion.
8. The bending control assembly according to claim 6, characterized in that: The guide member is provided with a pin, and the pin is in smooth contact with the second pull wire.
9. The bending control assembly according to claim 6, characterized in that: The traction member is provided with a third connection portion, and the proximal end of the second pull wire is connected to the third connection portion.
10. The bending control assembly according to claim 6, characterized in that: The adjusting mechanism also includes a knob, a first threaded sleeve and a second threaded sleeve. The knob is rotatably connected to the shell. The knob is connected to the first threaded sleeve and is used to drive the first threaded sleeve to rotate around the fixed rod in the shell. The second threaded sleeve is arranged between the fixed rod and the first threaded sleeve. The second threaded sleeve is threadedly matched with the first threaded sleeve, and the second threaded sleeve is circumferentially limited to the fixed rod. When the knob drives the first threaded sleeve to rotate, the second threaded sleeve moves along the axial direction of the fixed rod. The traction member is linked to the second threaded sleeve.
11. A conveying system, characterized in that: It comprises a catheter and a bending control assembly as described in any one of claims 1 to 10, wherein the catheter and the bending control pipe are arranged in a sleeve-type arrangement, and the bending control assembly is used to drive the catheter to bend when bending occurs, so as to adjust the bending direction and bending angle of the catheter.