Modular assembly of a pull wire with adjustable bending sheath

Abstract

The present application relates to a module assembly type pull wire structure of an adjustable bending sheath, which comprises a pull wire and an assembly module. In one aspect, the present application is based on the premise that the radius of the arc surface formed by the arc-shaped abutting part is greater than or equal to the minimum bending radius of the bending end part, the thickness of the assembly module is greater than or equal to the outer diameter of the pull wire, the traditional pull wire ring is replaced by the assembly module, and the required bending control ability can be achieved. In another aspect, the present application is based on the polymer coating, the stress area between the distal end of the pull wire and the polymer is increased, the distal end of the pull wire is more stably fixed in the polymer of the sheath, and the polymer is effectively prevented from deforming or the distal end of the pull wire is effectively prevented from displacing when the adjustable bending sheath is controlled to bend, the occurrence of the "bulge phenomenon" is effectively avoided, the risk of failure and leakage of the adjustable bending sheath is reduced, and in addition, the assembly module is flexible to select and is not limited by specifications, and has strong universality and practicability.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of medical devices, and particularly relates to a module assembly type pull wire structure of an adjustable bending sheath. BACKGROUND

[0002] At present, in minimally invasive interventional surgery (such as cardiac electrophysiology ablation, nerve intervention, and peripheral vascular treatment), the fixed bending angle of the head end of the traditional sheath often makes it difficult to accurately reach the complex anatomical target point, which limits the success rate and efficiency of the surgery, and the core technology of the adjustable bending sheath lies in the efficient linkage of the sheath proximal end control handle and the distal end bendable section. The surgeon rotates or pulls the handle, uses the internal push-pull wire or torque transmission system to remotely control the bending angle (usually more than 180°) and bending direction of the sheath head end in real time and accurately, and at the same time, the bending adjustment technology significantly improves the pointing control ability of the catheter / silicon wire, enabling it to more safely and efficiently pass through the tortuous blood vessels or cardiac cavity structures and reach the lesion location that traditional instruments cannot reach, providing key tool support for minimally invasive treatment of complex lesions.

[0003] However, in order to achieve bending adjustment, a pull wire structure is generally arranged in the sheath, and the commonly used pull wire structure includes a pull wire ring and a pull wire, wherein the pull wire passes through the pull wire ring from both ends and is positioned in the pull wire ring to form a distal end, and the exit end extends along the length direction of the sheath and forms a proximal end, that is, the proximal end of the pull wire is movable, and the distal end is generally fixed in the sheath wall by using the pull wire ring to fix the distal end of the pull wire, therefore, there are the following technical defects:

[0004] 1) As the main force (tension) component during sheath bending adjustment, the pull wire ring is generally made of a rigid material due to the wall thickness limitation of the sheath body and the high peak tension requirement during bending control. In order to ensure the strength of the pull wire ring, the production and processing cost and feasibility (high processing precision requirement), there is a limit minimum value for the wall thickness of the thinnest part of the pull wire ring threading hole, which leads to no reduction space for the wall thickness of the pull wire ring itself. Moreover, in order to facilitate the assembly of the pull wire ring, a gap fit is required, so the inner diameter of the pull wire ring is designed to be large, which leads to a large outer diameter of the pull wire ring under the condition of a certain wall thickness, and the large inner diameter may cause the pull wire ring to be eccentric in the adjustable bending sheath. In order to prevent the pull wire ring from leaking out of the adjustable bending sheath, even an excessive amount of polymer needs to be coated, which finally leads to the difficulty in reducing the wall thickness of the adjustable bending sheath, that is, not only does the pull wire ring occupy a large wall thickness space of the sheath, but also the wall thickness of the sheath is difficult to reduce.

[0005] 2) The processing precision and material performance requirements of the pull wire ring are relatively high, and it is difficult to eliminate the positioning gap between the pull wire and the pull wire ring during the pull wire assembly process. After the polymer is filled into the gap, it is extremely likely to form a "bulge phenomenon" on the surface of the sheath after being extruded and deformed by the pull wire, and even cause displacement or shedding of the distal end of the pull wire, increasing the risk of failure of the adjustable bending sheath.

[0006] 3) Each size of adjustable bending sheath tube needs to be designed with a corresponding size of pull wire ring, which cannot be universal, and the corresponding section of the pull wire ring is rigid, which causes a higher probability of rupture (i.e., a high probability of leakage) between the inner liner during the bending process. SUMMARY

[0007] In order to overcome the defects of the prior art, the purpose of the present application is to provide an improved module assembly type pull wire structure of adjustable bending sheath.

[0008] To solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0009] A module assembly type pull wire structure of adjustable bending sheath, comprising a pull wire having a pull wire distal end and a pull wire proximal end, the pull wire distal end having a curved end head and two lead wire portions, the pull wire structure further comprising an assembly module in arc contact with the inner side of the curved end head, wherein the arc contact portion forms an arc surface, and the radius of the arc surface is greater than or equal to the minimum bending radius of the curved end head; the thickness of the assembly module is greater than or equal to the outer diameter of the pull wire, and the polymer covers the assembly module, the curved end head and the lead wire portion to be relatively positioned at the distal end of the sheath.

[0010] Preferably, the center of the arc surface and the bending center of the curved end head coincide. In this way, the arc-shaped contact surface formed is the largest, thereby improving the firmness of the positioning.

[0011] According to a specific implementation and preferred aspect of the present application, the assembly module is an inner penetrating component, wherein a through hole is formed between the inner penetrating component and the pull wire distal end, and the polymer at the distal end of the sheath fills the through hole to position the pull wire distal end and the inner penetrating component. By using a block-shaped and inner penetrating manner, the pull wire ring scheme is replaced, and at the same time, based on the polymer filled in the through hole, the firmness between the pull wire at the distal end of the sheath and the assembly module is enhanced.

[0012] Preferably, the inner penetrating component is a sheet-shaped module having an arc surface, wherein the sheet-shaped module forms a through hole between the side surface not in contact with the pull wire distal end and the corresponding pull wire distal end. That is, the contact area is increased as much as possible, and the space of the through hole can be filled with polymer, thereby increasing the stress area between the pull wire distal end and the polymer, making the pull wire distal end more stably fixed in the polymer of the sheath, preventing the polymer from deforming or the pull wire distal end from displacing when the adjustable bending sheath is controlled to bend, and reducing the risk of failure of the adjustable bending sheath.

[0013] In some embodiments, the sheet-shaped module further has an assembly hole and / or an assembly groove formed thereon, and a portion of the polymer of the distal end of the sheath fills the assembly hole and / or the assembly groove. Based on the assembly hole or the assembly groove, the contact area is further increased, and the stability of the positioning of the distal end of the pull wire is improved.

[0014] Preferably, the assembly hole is a through hole. Based on the design of the assembly hole, not only is the positioning of the assembly facilitated, but the force area between the distal end of the pull wire and the polymer is also increased by the filling of the polymer.

[0015] In some embodiments, a hollow hole is formed in the middle of the sheet-shaped module, and the hollow hole is in communication with the through hole. In short, the sheet-shaped module in the shape of C is further filled to increase the force area between the distal end of the pull wire and the polymer based on the premise of effective contact of the curved surface.

[0016] According to one embodiment and preferred aspect of the present application, the inner penetrating component is a ring-shaped module, wherein the through hole includes a hollow area hole in the interior of the ring-shaped module, a through area hole formed between the side of the ring-shaped module not in contact with the distal end of the pull wire and the corresponding distal end of the pull wire. Based on the positioning of the inner support formed by the ring-shaped module, the function of the pull wire ring is replaced by the ring-shaped module under the filling of the polymer in the through hole.

[0017] Preferably, the ring-shaped module further has an assembly hole and / or an assembly groove formed thereon, and a portion of the polymer of the distal end of the sheath fills the assembly hole and / or the assembly groove. Based on the assembly hole or the assembly groove, the contact area is further increased, and the stability of the positioning of the distal end of the pull wire is improved, and the bending control ability of the pull wire structure is improved.

[0018] According to another embodiment and preferred aspect of the present application, the assembly module is a combined component, wherein the combined component includes a sleeving body matched with the curved inner side of the curved end head, and a threading body matched with the two lead wires respectively and allowing the pull wire to pass through. Based on the sleeving and threading way formed by the combined component, the distal end of the pull wire is positioned at the distal end of the sheath, that is, the function of the pull wire ring is replaced by the combined component.

[0019] Preferably, a sleeving channel is formed on the sleeving body, and a threading channel in communication with the sleeving channel is provided on the threading body. Based on the provision of the channels, the displacement rate of the pull wire after the sleeving is low.

[0020] In some embodiments, the sleeving channel is a sleeving groove recessed inward from the surface, the curved end head is embedded in the sleeving groove and sleeved on the sleeving body, and the curved end head is exposed from the embedded end face. Based on the sleeving and embedding way, the installation of the pull wire is facilitated, and under the premise of stable assembly, the polymer is filled into the assembly gap formed by the pull wire structure as much as possible to increase the contact area of the pull wire structure and improve the bending control ability of the pull wire structure.

[0021] Preferably, the threading channel is a threading groove recessed inward from the surface, and the lead wire part is exposed from the embedding end face. Further increasing the polymer filling covering capacity is added below the opening of the threading groove.

[0022] Preferably, the slot width of the sleeving groove is less than or equal to the outer diameter of the pull wire. Generally, the two are equal, but considering the requirement of firm embedding, an interference fit assembly method can be used. Similarly, the groove depth of the threading groove is less than or equal to the outer diameter of the pull wire, and generally the two are equal, but considering the thickness of the entire threading body (if the groove is too deep, the strength is low and it is easy to be damaged, increasing the probability of bulging; on the contrary, if the groove is too shallow, the firmness of the embedding of the two will be affected), the pull wire slightly protrudes from the threading groove.

[0023] In some specific embodiments, the sleeving groove and the threading groove are formed by recessing from the same side. This processing is very convenient.

[0024] Alternatively, the sleeving groove and the threading groove are formed by recessing from opposite sides. Based on the reverse setting, it mainly increases the relative restriction on the inside and outside of the bending adjustment, thereby better assisting the bending adjustment.

[0025] In addition, the two threading grooves are arranged in parallel; or, the two threading grooves gradually converge along the threading direction. Whether parallel or intersecting (gradually converging), the lead wire part can be inserted into one pull wire channel or inserted into two pull wire channels that are relatively close together.

[0026] Further, an assembly groove is further provided on the sleeving body, wherein the assembly groove transversely crosses and is in through communication with the sleeving groove and the threading groove. Based on the assembly hole or the assembly groove, the contact area is further increased, the stability of the positioning of the distal end of the pull wire is improved, and the bending control ability of the pull wire structure is improved.

[0027] Compared with the prior art, the present application has the following advantages:

[0028] The existing pull wire ring structure, as the main force (tension) component when the sheath tube is bent, generally uses a rigid material due to the wall thickness limitation of the sheath tube and the high peak tension demand when the bending is controlled. In order to ensure the strength of the pull wire ring, the production and processing cost and feasibility (high processing precision requirement), there is a limit minimum value for the wall thickness of the thinnest part of the pull wire ring hole, which leads to no reduction space for the wall thickness of the pull wire ring itself. Moreover, in order to facilitate the assembly of the pull wire ring, a gap fit is also needed, so the inner diameter of the pull wire ring is designed to be larger, which leads to the outer diameter of the pull wire ring being larger under the condition of the wall thickness, and the larger inner diameter may cause the pull wire ring to have a certain eccentricity in the adjustable bending sheath. In order to prevent the pull wire ring from leaking outside the adjustable bending sheath, even more polymer needs to be coated, which finally leads to the wall thickness of the adjustable bending sheath being unable to be reduced, that is, not only does the pull wire ring occupy a larger wall thickness space of the sheath tube, but also the wall thickness of the sheath tube is difficult to reduce. The processing precision and material performance requirement of the pull wire ring are relatively high, and in addition, it is difficult to eliminate the positioning gap between the pull wire and the pull wire ring in the pull wire assembly process. After the polymer is filled into the gap, it is extremely likely to form a "bulge phenomenon" on the surface of the sheath tube after being extruded and deformed by the pull wire, which may even cause the displacement or falling of the distal end of the pull wire, increasing the risk of failure of the adjustable bending sheath. The adjustable bending sheath of each specification needs to be designed with a corresponding specification of the pull wire ring, which cannot be universal, and in the bending process, due to the rigidity of the pull wire ring, the corresponding section has a high probability of rupture (i.e., high leakage probability) caused by friction with the inner liner, and so on. The present application ingeniously solves the various existing deficiencies by overall design of the pull wire structure. After using the pull wire structure, the arc-shaped resistance is first formed by the assembly module, and then the assembly module, the curved end head and the lead part are coated by the polymer to be relatively positioned at the distal end of the sheath tube. Then, the bending operation of the distal end of the sheath tube can be performed by operating the proximal end of the sheath tube. Therefore, on the one hand, based on the premise that the radius of the arc surface formed by the arc-shaped resistance part is greater than or equal to the minimum bending radius of the curved end head, and the thickness of the assembly module is greater than or equal to the outer diameter of the pull wire, the assembly module replaces the traditional pull wire ring and can achieve the required bending control ability. On the other hand, based on the coating of the polymer, the stress area between the distal end of the pull wire and the polymer is increased, so that the distal end of the pull wire is more stably fixed in the polymer of the sheath tube, and the deformation of the polymer and the displacement of the distal end of the pull wire during the bending control of the adjustable bending sheath are effectively prevented, the occurrence of the "bulge phenomenon" is effectively avoided, the risk of failure and leakage of the adjustable bending sheath is reduced, and the wall thickness of the sheath tube can be reduced. In addition, the assembly module is selected flexibly and is not limited by the specification, and has strong universality and practicality. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 Structure diagram of the pull wire structure of Example 1 (sheet one);

[0030] Figure 2 Structure diagram of the pull wire structure of Example 1 (sheet two);

[0031] Figure 3 Structure diagram of the assembly module of Example 1 Figure 1 ;

[0032] Figure 4 Structure diagram of the assembly module of Example 1 Figure 2 ;

[0033] Figure 5 Structure diagram of the assembly module of Example 1 Figure 3 ;

[0034] Figure 6 Structure diagram of the pull wire structure of Example 2 (annular one)

[0035] Figure 7 Structure diagram of the pull wire structure of Example 2 (annular two)

[0036] Figure 8 Structure diagram of the assembly module of Example 2 Figure 1 ;

[0037] Figure 9 Structure diagram of the assembly module of Example 2 Figure 2 ;

[0038] Figure 10 Structure diagram of the pull wire structure of Example 3 Figure 1 ;

[0039] Figure 11 Front view diagram of Figure 10 ;

[0040] Figure 12 Left view diagram of Figure 11 ;

[0041] Figure 13 Structure diagram of the pull wire structure of Example 4 Figure 2 ;

[0042] Figure 14 Front view diagram of Figure 13 ;

[0043] Figure 15 Left view diagram of Figure 14 ;

[0044] Figure 16 Structure diagram of the pull wire structure of Example 5 Figure 3 ;

[0045] Figure 17 Front view diagram of Figure 16 ;

[0046] Figure 18 Left view diagram of Figure 17Fig. 2 is a left view schematic diagram of the device of Fig. 1 ;

[0047] 1, pull wire; 10, pull wire distal end; 100, curved tip portion; 101, lead wire portion; 11, pull wire proximal end;

[0048] 2, assembly module; 20, sheath body; 200, sheath channel; 21, threading body; 210, threading channel;

[0049] 3, through hole; 31, hollow hole; 32, through hole; 33, hollow region hole; 34, through region hole; 4, assembly hole; 5, assembly slot. DETAILED DESCRIPTION

[0050] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of different ways beyond the specific embodiments described herein and by persons skilled in the art without departing from the spirit and scope of the present application, and it is therefore intended that all such changes and modifications be included within the scope of the present application.

[0051] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0052] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implying the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0053] In the present application, unless specifically defined otherwise, the terms "mounting", "connected", "connecting", "fixed", and "fixedly" are used broadly and encompass both direct and indirect mounting, connecting, and fixing, such as fixed connection, detachable connection, or integral connection; mechanical connection, or electrical connection; direct connection, or indirect connection via intermediate medium; internal communication between two elements, or interaction between two elements. The specific meaning of the above terms in the present application can be understood according to the specific circumstances by those of ordinary skill in the art.

[0054] In the present application, unless specifically defined otherwise, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features via an intermediate medium. Moreover, the first feature "above", "over", and "on" the second feature can be directly above or obliquely above the second feature, or simply indicate that the first feature is higher in horizontal height than the second feature. The first feature "below", "under", and "under" the second feature can be directly below or obliquely below the second feature, or simply indicate that the first feature is lower in horizontal height than the second feature. It should be noted that when an element is referred to as "fixed to" or "provided on" another element, it can be directly on the other element or there can be a mediating element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or there can be a mediating element. The terms "vertical", "horizontal", "up", "down", "left", "right", and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation.

[0055] In the present application, unless specifically defined otherwise, the terms "mounting", "connected", "connecting", "fixed", and "fixedly" are used broadly and encompass both direct and indirect mounting, connecting, and fixing, such as fixed connection, detachable connection, or integral connection; mechanical connection, or electrical connection; direct connection, or indirect connection via intermediate medium; internal communication between two elements, or interaction between two elements. The specific meaning of the above terms in the present application can be understood according to the specific circumstances by those of ordinary skill in the art. Figures 1 to 5 As shown in the embodiment 1, the module assembly type pull wire structure of the adjustable bending sheath of the present embodiment includes a pull wire 1 and an assembly module 2.

[0056] In some specific embodiments, the pull wire 1 has a pull wire distal end 10 and a pull wire proximal end 11, wherein the pull wire distal end 10 has a bending end head 100 and two lead wire parts 101. The assembly module 2 is an inner penetrating part, wherein a through hole 3 is formed between the inner penetrating part and the pull wire distal end 10, and the thickness of the inner penetrating part is equal to the outer diameter of the pull wire 1. Part of the polymer covers the inner penetrating part, the bending end head 100, and the lead wire parts 101 to relatively position the sheath distal end, and the remaining polymer fills the through hole 3 to position the pull wire distal end 10 and the inner penetrating part. That is, the inner penetrating method replaces the pull wire ring scheme, and based on the polymer filled in the through hole 3, the firmness between the pull wire 1 and the assembly module 2 at the sheath distal end is enhanced.

[0057] Specifically, the inner fitting component is a sheet-shaped module with an arc surface, the sheet-shaped module is in contact with the inner side of the curved end head 100 from the arc contact part, and a through hole 3 is formed between the side of the sheet-shaped module not in contact with the pull wire distal end 10 and the corresponding pull wire distal end 10, wherein the arc contact part forms an arc surface, the radius of the arc surface is greater than or equal to the minimum bending radius of the curved end head 100; the center of the arc surface coincides with the bending center of the curved end head 100. In this way, the arc-shaped contact surface formed is maximized, thereby improving the firmness of positioning. That is, the contact area is increased as much as possible, and the space of the through hole 3 can be filled with a polymer, thereby increasing the stress area between the pull wire distal end 10 and the polymer, making the pull wire distal end 10 more stably fixed in the polymer of the sheath, preventing the polymer from deforming or the pull wire distal end 10 from shifting when the adjustable bending sheath is controlled to bend, thereby reducing the risk of failure of the adjustable bending sheath.

[0058] In this example, the sheet-shaped module is a disc module, a disc module with an angle at the bottom, an oval module, an oval module with an angle at the bottom, or a C-shaped module, wherein any one of the disc module, the disc module with an angle at the bottom, the oval module, the oval module with an angle at the bottom, and the pull wire distal end 10 forms a through hole 3; the through hole 3 of the C-shaped module includes an internal hollow hole 31 and a through hole 32 formed between the C-shaped module and the pull wire distal end 10, wherein the hollow hole 31 and the through hole 32 are in communication.

[0059] In order to improve the convenience of installing the sheet-shaped module, assembly holes 4 are provided on the disc module, the disc module with an angle at the bottom, the oval module, the oval module with an angle at the bottom, and the C-shaped module. At this time, in addition to meeting the above-mentioned convenience requirements for installation, the assembly holes 4 also need to meet the requirements for the polymer to be filled through.

[0060] To further increase the stress area between the pull wire distal end 10 and the polymer, assembly slots 5 are provided on the disc module, the disc module with an angle at the bottom, the oval module, the oval module with an angle at the bottom, and the C-shaped module, in addition to the assembly holes 4. Based on the assembly holes 4 and the assembly slots 5, the contact area is further increased, and the stability of the positioning of the pull wire distal end 10 is improved.

[0061] Based on the data analysis of Table 1, it can be seen that the pull wire structure of the present embodiment can completely replace the traditional pull wire ring structure and achieve the desired bending control effect.

[0062]

[0063] Based on the data analysis of Table 1, it can be seen that the pull wire structure of the present embodiment can completely replace the traditional pull wire ring structure and achieve the desired bending control effect.

[0064] Example 2, as Figures 6 to 9As shown, the adjustable bending sheath of this embodiment has a modular assembly type pull wire structure, which includes a pull wire 1 and an assembly module 2 similar to those in Embodiment 1.

[0065] Specifically, assembly module 2 is a hollow internal component, wherein the through hole 3 includes a hollow area hole 33 inside the annular module and a through area hole 34 formed between the side of the annular module that does not contact the distal end 10 of the pull wire and the corresponding distal end 10 of the pull wire. Based on the internal support positioning formed by the annular module and the polymer filling formed by the through hole 3, the annular module replaces the function of the pull wire ring.

[0066] In this example, the ring module can be a circular ring module, a circular ring module with a flat bottom, an elliptical ring module, or an elliptical ring module with a flat bottom.

[0067] To further increase the contact area, improve the stability of the positioning of the far end 10 of the pull wire, and enhance the bending control capability of the pull wire structure, assembly grooves 5 are respectively provided on the circular ring module, the circular ring module with a flat bottom, the elliptical ring module, and the elliptical ring module with a flat bottom. The polymer at the far end of the sheath tube is partially filled into the assembly grooves 5.

[0068] In summary, under the premise of the same sheath size (outer diameter 6.85 mm; wall thickness 0.65 mm), the bending control capability test was carried out, and the results are shown in Table 2.

[0069]

[0070] Based on the data analysis in Table 2, it can be seen that the wire structure of this embodiment can completely replace the traditional wire ring structure and achieve the required bending control effect.

[0071] Example 3, as Figures 10 to 12 As shown, the adjustable bending sheath of this embodiment has a modular assembly type pull wire structure, which includes a pull wire 1 and an assembly module 2. The pull wire 1 is the same as the pull wire 1 in embodiment 1, but the difference is in the assembly module 2.

[0072] Specifically, assembly module 2 is a combined component (one-piece molded part), which includes a sleeve body 20 that matches the inner curved surface of the bent end head 100, and a threading body 21 that matches the two lead wire parts 101 and allows the pull wire 1 to pass through. Based on the threading method formed by the combined component, the distal end 10 of the pull wire is positioned at the distal end of the sheath, that is, the function of the pull wire ring is replaced by the combined component.

[0073] In some specific embodiments, the thickness of the sleeve body 20 and the threading body 21 are equal, and the thickness of the sleeve body 20 and the threading body 21 is greater than the outer diameter of the pull wire 1 (generally, the thickness of the assembly module 2 is about 0.4 mm, that is, 3 / 5 of the sheath wall thickness, and the outer diameter of the pull wire 1 is about 0.24 mm). The threading body 21 is provided with a threading channel 210. The channel setting makes the displacement rate between the pull wire 1 and the assembled components low after threading. In this example, the threading channel 210 is a threading groove that is recessed from the surface inward, and the lead wire portion 101 is exposed from the embedded end face. With the threading groove open, the polymer filling and covering capacity is further increased. At the same time, the groove depth is less than or equal to the outer diameter of the pull wire 1. Generally, the two are equal, but considering the thickness of the entire threading body 21 (if the groove is too deep, its own strength is low, it is easy to be damaged, and the probability of bulging increases; conversely, if the groove is too shallow, the firmness of the two will be affected), the pull wire 1 protrudes slightly from the threading groove.

[0074] In this example, the two wire slots are set in parallel, and the two pull wire channels are inserted into them respectively.

[0075] In summary, under the premise of the same sheath size (outer diameter 6.85 mm; wall thickness 0.65 mm), the bending control capability test was carried out, and the results are shown in Table 3.

[0076]

[0077] Based on the data analysis in Table 3, it can be seen that the wire structure of this embodiment can completely replace the traditional wire ring structure and achieve the required bending control effect.

[0078] Example 4, as Figures 13 to 15 As shown, the adjustable bending sheath tube of this embodiment has a modular assembly type pull wire structure, which includes a pull wire 1 and an assembly module 2. The pull wire 1 is the same as the pull wire 1 in embodiment 3, and the assembly module 2 is similar to the assembly module 2 in embodiment 3. The specific differences are as follows.

[0079] The two threading grooves gradually approach each other along the threading direction. The far end 10 of the pull wire is fitted onto the main body 20 from the bent end head 100. The two lead wire parts 101 are embedded in the threading grooves and inserted into a pull wire channel relatively close to each other.

[0080] In summary, under the premise of the same sheath size (outer diameter 6.85 mm; wall thickness 0.65 mm), the bending control capability test was carried out, and the results are shown in Table 4.

[0081]

[0082] Based on the data analysis in Table 4, it can be seen that the wire structure of this embodiment can completely replace the traditional wire ring structure and achieve the required bending control effect.

[0083] Embodiment 5, as shown in the figure, the module assembly type pull wire structure of the adjustable bending sheath of the present embodiment includes a pull wire 1 and an assembly module 2, wherein the pull wire 1 is the same as that in Embodiment 4, except that the assembly module 2. Figures 16 to 18 In the present example, the assembly module 2 is a combined component, wherein the combined component includes a sleeving body 20 matched with the bending inner side of the bending tip part 100, and threading bodies 21 respectively matched with the two lead wire parts 101 and through which the pull wire 1 is threaded. The sleeving way based on the combined component positions the pull wire distal end 10 at the sheath distal end, i.e., the combined component replaces the function of the pull wire ring.

[0084] Specifically, the thicknesses of the sleeving body 20 and the threading body 21 are equal, and the thicknesses of the sleeving body 20 and the threading body 21 are greater than the outer diameter of the pull wire 1 (generally, the thickness of the assembly module 2 is about 0.4 mm, i.e., 3 / 5 of the sheath wall thickness, and the outer diameter of the pull wire 1 is about 0.24 mm), a sleeving channel 200 is formed on the sleeving body 20, and a threading channel 210 is provided on the threading body 21 and communicates with the sleeving channel 200. Based on the provision of the channels, the displacement rate of the pull wire 1 after sleeving is low. The sleeving channel 200 is a sleeving groove recessed inward from the surface, the bending tip part 100 is embedded in the sleeving groove and sleeved on the sleeving body 20, and the bending tip part 100 is exposed from the embedded end face. Based on the sleeving embedding manner, the installation of the pull wire 1 is facilitated, and at the same time, the assembly stability is maintained, and under the premise of the assembly stability, the polymer is filled into the assembly gap formed by the pull wire structure as much as possible to increase the contact area of the pull wire structure and improve the bending control ability of the pull wire structure.

[0085] Specifically, the threading channel 210 is a threading groove recessed inward from the surface, and the lead wire part 101 is exposed from the embedded end face. In the open state of the threading groove, the polymer filling and coating ability is further increased. The groove width of the sleeving groove is less than or equal to the outer diameter of the pull wire 1. Generally, the two are in an equal relationship, but an interference fit assembly method can be used considering the embedding firmness requirement. Similarly, the groove depth of the threading groove is less than or equal to the outer diameter of the pull wire 1, and generally the two are in an equal relationship, but the pull wire 1 slightly protrudes from the threading groove considering the thickness of the entire threading body 21 (if the groove is too deep, the self-strength is low, the threading body 21 is easy to be damaged, and the probability of bulging is increased; on the contrary, if the groove is too shallow, the embedding firmness of the two will be affected).

[0086] In some specific embodiments, the sleeving groove and the threading groove are formed by being recessed inward from the same side. This processing is very convenient. Alternatively, the sleeving groove and the threading groove are formed by being recessed inward from opposite sides. Based on the reverse setting, the relative restriction on the inner and outer sides of the bending is increased, thereby better assisting the bending.

[0087]

[0088] ​In addition, the two threading grooves are arranged in parallel or gradually approach each other along the threading direction. No matter parallel or intersecting (gradually approach each other), the lead wire part 101 can be inserted into a pull wire channel or into two pull wire channels respectively which approach each other. Further, the assembly body 20 is further provided with an assembly groove 5 which transversely penetrates and communicates with the assembly groove and the threading groove. Based on the assembly groove 5, the contact area is further increased, the stability of the positioning of the pull wire distal end 10 is improved, and the bending control ability of the pull wire structure is improved.

[0089] In summary, under the premise of the same sheath size (outer diameter of 6.85 mm; wall thickness of 0.65 mm), the bending control ability test is carried out, and the results are shown in Table 5.

[0090]

[0091] Based on the data analysis of Table 5, it can be known that the pull wire structure of the embodiment can completely replace the traditional pull wire ring structure and can achieve the required bending control effect.

[0092] In summary, after adopting the pull wire structure, the arc-shaped resistance is first formed by the assembly module, then the assembly module, the curved end head and the lead wire part are covered by the polymer to be positioned relative to the sheath distal end, and then the sheath distal end bending operation is performed by operating the sheath proximal end. Therefore, on the one hand, based on the arc-shaped resistance part forming an arc surface with a radius greater than or equal to the minimum bending radius of the curved end head, and the thickness of the assembly module being greater than or equal to the outer diameter of the pull wire, the assembly module replaces the conventional pull wire ring, and can achieve the required bending control ability; on the other hand, based on the polymer covering, the stress area between the pull wire distal end and the polymer is increased, so that the pull wire distal end is more stably fixed in the polymer of the sheath, and the "bulge phenomenon" can be effectively avoided, the risk of adjustable bending sheath failure and leakage is reduced, and the sheath wall thickness can be thinned. In addition, the assembly module is flexible to choose and is not limited by specifications, and has high universality and practicality; on the third aspect, the center of the arc surface and the bending center of the curved end head coincide, so that the formed arc-shaped contact surface is the largest, and the positioning firmness is improved; on the fourth aspect, the inner penetrating part replaces the pull wire ring scheme, and based on the polymer filled in the penetrating through hole, the firmness between the pull wire and the assembly module at the sheath distal end is enhanced, and based on the configuration of the assembly hole and / or assembly groove, the contact area is further increased, and the stability of the pull wire distal end positioning is improved. In addition, the design of the assembly hole not only facilitates positioning and assembly, but also can increase the stress area between the pull wire distal end and the polymer by filling the polymer; on the fourth aspect, the combined part replaces the pull wire ring scheme, and based on the polymer filled in the penetrating through hole, the firmness between the pull wire and the assembly module at the sheath distal end is enhanced, and based on the way of embedding the sleeve into the sleeve, the installation of the pull wire is facilitated, and under the premise of maintaining stable assembly, the polymer is filled into the assembly gap formed by the pull wire structure as much as possible to increase the contact area of the pull wire structure and improve the bending control ability of the pull wire structure; on the fifth aspect, the width of the sleeve groove is less than or equal to the outer diameter of the pull wire, and in general, the two are equal, but considering the requirement of embedding firmness, an interference fit assembly method can be used. Similarly, the depth of the threading groove is less than or equal to the outer diameter of the pull wire, and in general, the two are equal, but considering the thickness of the entire threading body (if the groove is too deep, the self-strength is low, and it is easy to be damaged, increasing the probability of bulging; on the contrary, if the groove is too shallow, the firmness of the embedding of the two will be affected), the pull wire slightly protrudes from the threading groove; on the sixth aspect, the sleeve groove and the threading groove are formed by self-contralateral relative concave, which is very convenient for processing, or the sleeve groove and the threading groove are formed by self-contralateral relative concave, based on the reverse setting, it mainly increases the relative restriction on the inside and outside of the bending, so as to better assist the bending; on the seventh aspect, the two threading grooves are arranged in parallel; or the two threading grooves gradually converge along the threading direction, whether parallel or intersecting (gradually converging), the lead wire part can be inserted into one pull wire channel or inserted into two pull wire channels that gradually converge relative to each other.The eighth aspect is further provided with an assembling groove on the sleeve body, wherein the assembling groove is transversely communicated with the sleeve groove and the threading groove, and the assembling hole or the assembling groove further increases the contact area to improve the stability of the positioning of the distal end of the pull wire and improve the bending control ability of the pull wire structure.

[0093] The above embodiments are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and essence of the present application shall be covered within the protection scope of the present application.

Claims

1. A modular assembly type pull wire structure for an adjustable bending sheath, comprising a pull wire having a distal end and a proximal end, wherein the distal end of the pull wire has a bent end head and two lead wire portions, characterized in that: The draw wire structure also includes an assembly module that arcs against the inner side of the bent end head, wherein the arc-shaped contact portion forms an arc surface, and the radius of the arc surface is greater than or equal to the minimum bending radius of the bent end head; the thickness of the assembly module is greater than or equal to the outer diameter of the draw wire, and the polymer covers the assembly module, the bent end head, and the lead wire portion to be relatively positioned at the distal end of the sheath; the assembly module is an inner through-hole component, wherein a through-hole is formed between the inner through-hole component and the distal end of the draw wire, and the inner through-hole component is an annular module, wherein the through-hole includes a hollow area hole inside the annular module, a through area hole formed between the side of the annular module that does not contact the distal end of the draw wire and the corresponding distal end of the draw wire.

2. The modular assembly type draw wire structure of the adjustable bending sheath according to claim 1, characterized in that: The center of the arc surface coincides with the center of the bend at the bend end.

3. The modular assembly type draw wire structure of the adjustable bending sheath according to claim 1, characterized in that: The polymer at the distal end of the sheath fills the through-hole to position the distal end of the draw wire and the inner part.

4. The modular assembly type draw wire structure of the adjustable bending sheath according to claim 1, characterized in that: The annular module also has assembly holes and / or assembly grooves, and a portion of the polymer at the distal end of the sheath fills the assembly holes and / or assembly grooves.

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