Curved tube, passive curved section, insertion portion, and endoscope

Abstract

Provided in the present application are a curved tube, a passive curved section, an insertion portion, and an endoscope, relating to the technical field of endoscopes. The curved tube disclosed in the present application is used for the passive curved section of the endoscope, and the distal end of the curved tube is used for being connected to an active curved section of the endoscope. The curved tube comprises a plurality of slits. The slits penetrate through the interior of the curved tube, the slits are at least arranged in a portion of the side of the curved tube close to the distal end thereof, and the plurality of slits are arranged along an axial direction of the curved tube. Along the direction from the distal end to the proximal end of the curved tube, the radial depth of each slit gradually decreases. The solutions can at least be used for solving the problem of the low maneuverability of an insertion portion in the related art.

Description

Bent tube, passive bending section, insertion portion, and endoscope TECHNICAL FIELD

[0001] The present application relates to the technical field of endoscopes, and in particular to a bent tube, a passive bending section, an insertion portion, and an endoscope. BACKGROUND

[0002] An endoscope is a device widely used in the medical field, which can directly enter the natural ducts of the human body for examination, providing sufficient diagnostic information for doctors to effectively treat diseases. The insertion portion includes a passive bending section and an active bending section connected to the distal end of the passive bending section. During the insertion process, the passive bending section can cooperate with the action of the active bending section to help the endoscope smoothly pass through the complex human body cavity.

[0003] In related technologies, an operator can rotate the insertion portion circumferentially outside the patient's body to adjust the bendable direction of the insertion portion in the patient's body. However, it is often found in actual operation that such circumferential rotation cannot be effectively transmitted to the insertion portion, so that the insertion portion cannot achieve the expected bending action, resulting in unsatisfactory operation effect. UTILITY MODEL CONTENT

[0004] The present application discloses a bent tube, a passive bending section, an insertion portion, and an endoscope to solve the technical problem of low controllability of the insertion portion in related technologies.

[0005] In a first aspect, the present application provides a bent tube for a passive bending section of an endoscope, a distal end of the bent tube being used to connect an active bending section of the endoscope, the bent tube comprising a slit, the slit penetrating to the inside of the bent tube, the slit being provided at least on the side of the bent tube close to the distal end thereof, and a plurality of slits being arranged along the axial direction of the bent tube; along the direction from the distal end to the proximal end of the bent tube, the radial depth of each slit gradually decreases.

[0006] In some embodiments, the plurality of slits includes a plurality of slit groups distributed along the axial direction of the bent tube, wherein the radial depth of the slits in the slit group closer to the distal end of the bent tube is greater than the radial depth of the slits in the slit group closer to the proximal end of the bent tube.

[0007] In some embodiments, along the direction from the distal end to the proximal end of the bent tube, the radial depth of one of the adjacent slits is greater than the radial depth of the other adjacent slit.

[0008] In some embodiments, the curved tube has a traction rope mounting part combination distributed along the axial direction of the curved tube; the traction rope mounting part combination comprises traction rope mounting parts arranged in diametrically opposite positions of the curved tube, and the traction rope mounting parts in the traction rope mounting part combination are arranged adjacently; the adjacent traction rope mounting part combinations are arranged at intervals in the axial direction of the curved tube, and a plurality of the slits are distributed along the interval paths of the adjacent traction rope mounting part combinations.

[0009] In some embodiments, in the axial direction of the curved tube, each of the traction rope mounting parts is arranged corresponding to one slit on the diametrically opposite side.

[0010] In some embodiments, the curved tube has a plurality of axially connected curved units, and the traction rope mounting parts are arranged corresponding to the adjacent joint portions.

[0011] In some embodiments, the distribution path of the slits is opposite to the extension path of the traction rope.

[0012] In some embodiments, the distribution path of the slits is staggered with the extension path of the traction rope in the axial direction of the curved tube.

[0013] In a second aspect, the present application provides a passive curved section comprising the curved tube of the first aspect of the present application.

[0014] In some embodiments, the passive curved section further comprises a main hose connected to the proximal end of the curved tube, and the rigidity of the main hose is greater than the rigidity of the proximal end of the curved tube.

[0015] In some embodiments, the proximal end of the curved tube has a spigot portion provided with a joint slit, the distal end of the main hose has a butt joint portion, the butt joint portion is in interference fit with the portion of the spigot portion provided with the joint slit; and the end of the joint slit away from the butt joint portion is staggered with the end of the slit in the axial direction of the passive curved section.

[0016] In a third aspect, the present application provides an insertion portion comprising the passive curved section of the second aspect of the present application.

[0017] In a fourth aspect, the present application provides an endoscope comprising the insertion portion of the third aspect of the present application.

[0018] The present application has the following advantages and beneficial effects:

[0019] The gap in the bending tube disclosed by the embodiment of the present application can improve the bending performance of the bending tube, so that the operator can effectively drive the bending tube and the passive bending section to follow the active bending section to bend and adaptively cooperate with the action of the active bending section in the process of operating the endoscope.

[0020] Meanwhile, since the radial depth of the gap gradually decreases along the direction from the distal end to the proximal end of the bending tube, it is shown that the rigidity of the part of the bending tube close to the proximal end is greater than the rigidity of the part of the bending tube close to the distal end, and then the rigidity of the passive bending section has a gradual change effect, and the coaxiality of the bending tube close to the operating handle side is better, and the operator can effectively achieve the expected bending action in the case of rotating the insertion part.

[0021] Compared with the related art, the bending tube of the embodiment of the present application can consider both the bending performance of the bending tube and the situation that the operator avoids the situation that the expected bending action cannot be achieved due to poor coaxiality when rotating in the circumferential direction, and thus is beneficial to improve the operability of the insertion part on the premise that the bending tube has bending performance. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0023] FIG. 1 is a schematic view of the connection structure of the bending tube and the active bending section according to the embodiment of the present application;

[0024] FIG. 2 is a schematic view of the connection of the bending tube and the active bending section according to the embodiment of the present application;

[0025] FIG. 3 is a schematic view of the connection of the bending tube and the active bending section according to the embodiment of the present application;

[0026] FIG. 4 is a schematic view of the bending tube according to the embodiment of the present application;

[0027] FIG. 5 is a schematic view of the bending tube according to the embodiment of the present application;

[0028] FIG. 6 is a schematic view of the bending tube according to the embodiment of the present application;

[0029] FIG. 7 is an exploded schematic view of the passive bending section according to the embodiment of the present application;

[0030] FIG. 8 is a schematic view of the structure of the passive bending section according to the embodiment of the present application;

[0031] Fig. 9 is a partial exploded view of the connection of the splicing portion and the main hose according to an embodiment of the present application;

[0032] Fig. 10 is a partial view of the connection of the splicing portion and the main hose according to an embodiment of the present application;

[0033] Fig. 11 is a partial view of the connection of the splicing portion and the main hose according to an embodiment of the present application;

[0034] Fig. 12 is an exploded view of the splicing portion according to an embodiment of the present application;

[0035] Fig. 13 is a view of the structure of the endoscope according to an embodiment of the present application.

[0036] The reference signs in the drawings are:

[0037] 100, curved tube; 110, splicing portion; 1110, joint seam;

[0038] 200, gap group; 210, gap;

[0039] 300, traction cord mounting portion group; 310, traction cord mounting portion;

[0040] 400, bending unit; 410, joint portion;

[0041] 500, main hose; 510, mating section;

[0042] 600, actively bending section;

[0043] 700, splicing portion. DETAILED DESCRIPTION

[0044] In order to make the objectives, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described in detail below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0045] The terms "first", "second", and the like in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than that illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of a kind and do not limit the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / ", generally indicates that the objects before and after are in an "or" relationship.

[0046] In the related art, the insertion part needs to consider the bending performance, so that the active bending section and the passive bending section have different bending degrees. The active bending section needs to have good bending ability to achieve the purpose of control. Therefore, in general, the active bending section is made by hinging through multiple snake bone units. However, the passive bending section has relatively low demand for bending performance. In most cases, the passive bending section mainly cooperates with the active bending section to follow, so as to help the endoscope smoothly pass through the complex human body cavity. Therefore, in general, the surface of the passive bending section is provided with a gap to realize the bending of the passive bending section.

[0047] Through research, the applicant found that, in general, the passive bending section also has a requirement for the radial depth of the gap. If the radial depth is too small, the bending performance of the passive bending section is poor, and the purpose of following the active bending section cannot be met.

[0048] If the radial depth is too large, the bending performance of the passive bending section is too good, which will cause the stiffness of the passive bending section to be small and the coaxiality to be poor. At this time, in the process of specifically operating the insertion part, since the bending direction of the active bending section is limited in only two opposite directions, in some surgical scenarios, the bending range of the active bending section cannot meet the needs of the operator in the surgical process. When the insertion part cannot observe the lesion or the observation of the lesion is not clear after being inserted into the human body cavity, the insertion part needs to be rotated to meet the demand of adjusting the observation direction. Since the coaxiality of the passive bending section is poor, the passive bending section is easy to twist by itself, so that the operator is not easy to control the insertion part to realize the expected bending action in the human body cavity, which is not conducive to the operator's control of the insertion part.

[0049] In view of this, in a first aspect, some embodiments of the present application provide a bending tube. The bending tube is applied to a passive bending section of an endoscope, and the distal end of the bending tube is used to connect an active bending section of the endoscope. Of course, it is not limited to the field of endoscope technology.

[0050] Please refer to FIGS. 1-13. In some embodiments, the bending tube 100 includes a gap 210, the gap 210 penetrates to the inside of the bending tube 100, the gap 210 is at least provided on the side of the bending tube 100 close to the distal end thereof, and the gap 210 is arranged in multiple along the axial direction of the bending tube 100. After the bending tube 100 is provided with the gap 210, the bending performance of the bending tube 100 itself is improved, so as to meet the demand of following the active bending section 600. For example, in order to improve the processing efficiency of the gap 210, the gap 210 can be made by cutting, and at the same time, the multiple gaps 210 formed by cutting can be relatively more regular.

[0051] Meanwhile, the radial depth of each slit 210 gradually decreases in a direction from the distal end to the proximal end of the curved tube 100. For example, the radial depth of the slit 210 can be in a radial direction of the curved tube 100, and can also be a size component of the depth of the slit 210 in the radial direction, i.e., the deformation of the slit 210 in a direction slightly deviating from the radial direction can also be regarded as the radial depth of the slit 210. In the gradual decrease of the radial depth of the slit 210, "gradual" can have at least two meanings. For example, the first meaning refers to a gradient decrease of the radial depth of the slit 210, and the radial depths of the slits 210 in the same gradient can be the same. The second meaning refers to a sequential decrease of the radial depth of the slit 210 according to the arrangement order of the slits 210. Other meanings of "gradual" are not described herein.

[0052] On this basis, the rigidity of the part of the curved tube 100 close to the proximal end is greater than the rigidity of the part of the curved tube 100 close to the distal end, so that the proximal end of the passive bending section has greater rigidity, and the deformation amplitude of the proximal end of the passive bending section is smaller during the rotation of the passive bending section controlled by the operator, i.e., the coaxiality is better, thereby facilitating the rotation of the distal end driven by the proximal end of the passive bending section to realize the circumferential rotation of the entire passive bending section, so as to rotate the insertion part to the expected circumferential position, and the operator can control the insertion part to perform a bending action at the position to achieve the expected bending effect.

[0053] For example, after the operator operates the insertion part to enter the human body cavity, it is found that the position of the insertion part cannot be well observed to the lesion whether in the current position or after adjusting the bending angle, and at this time, it is necessary to adjust the circumferential position of the insertion part to change the bending direction of the insertion part. At this time, if the insertion part is in a straight human body cavity, the insertion part can be directly rotated, and if the insertion part is in a curved human body cavity, the insertion part needs to be adjusted to a straight human body cavity for rotation. When rotating, the proximal end of the passive bending section has greater rigidity, and the deformation amplitude is smaller, so that the operator can effectively rotate the passive bending section to adjust the insertion part to the expected circumferential position. At this time, the operator can better observe the lesion after adjusting the circumferential position of the insertion part.

[0054] In summary, the operator can effectively achieve the expected bending action when the insertion part 700 needs to be rotated, thereby improving the operability of the insertion part 700 under the premise of the bending performance of the curved tube 100.

[0055] In some embodiments, in combination with FIG. 2, the plurality of slits 210 comprises a plurality of slit groups 200 distributed along the axial direction of the curved tube 100, wherein the radial depth of the slits 210 in the slit group 200 closer to the distal end of the curved tube 100 is greater than the radial depth of the slits 210 in the slit group 200 closer to the proximal end of the curved tube 100. For example, in the same slit group 200, the radial depth of each slit 210 is the same. The advantage of this arrangement is that in the curved tube 100, the rigidity of the section of the tube where the slit group 200 is located is consistent, so that the structural stability of the curved tube 100 is higher, and the curved tube 100 is not easily damaged when the operator manipulates the rotation of the insertion part 700. Moreover, the radial depth can be adjusted once when machining the slits 210 in the same group of slit groups 200, and each slit 210 in the same group of slit groups 200 can be machined, effectively improving the machining efficiency of the slits 210.

[0056] In some embodiments, in the direction from the distal end to the proximal end of the curved tube 100, the radial depth of one of the adjacent slits 210 located on the same side of the curved tube 100 is greater than the radial depth of the other adjacent slit 210. In this arrangement, the radial depth of the slit 210 decreases sequentially from the distal end to the proximal end according to the arrangement order of the slit 210, so that the coaxial variation of the curved tube 100 from the distal end to the proximal end is also smoother and more reliable.

[0057] In some embodiments, as shown in FIGS. 3 and 4, the curved tube 100 has a traction rope mounting part combination 300 distributed along the axial direction of the curved tube 100. For example, adjacent traction rope mounting part combinations 300 are arranged at intervals in the axial direction of the curved tube 100, and a plurality of slits 210 are distributed along the interval path of the adjacent traction rope mounting part combinations 300. In this arrangement, the adjacent traction rope mounting part combinations 300 on the curved tube 100 are at a certain distance, and the number of traction rope mounting part combinations 300 on the curved tube 100 can also be relatively arranged to be less, which is beneficial to improve the structural stability of the curved tube 100 and avoid the structural stability of the curved tube 100 from being reduced due to too many traction rope mounting part combinations 300.

[0058] For example, in combination with FIG. 5, the traction rope installation part combination 300 includes radially opposite traction rope installation parts 310 on the curved pipe 100, which are used for the insertion of traction ropes. The radially opposite traction rope installation parts 310 are used for the insertion of two traction ropes respectively, so as to achieve the purpose of bending the active curved section 600 in two opposite directions. For example, the traction rope installation part 310 is an arc-shaped insertion structure punched from the pipe wall of the curved pipe 100 towards the inside of the curved pipe 100, so that the traction rope can be inserted along the axial direction of the curved pipe 100 more conveniently, and the installation efficiency is improved. Of course, the traction rope installation part 310 can also have other structural forms, such as an arc-shaped insertion structure punched from the pipe wall of the curved pipe 100 towards the outside of the curved pipe 100.

[0059] In some embodiments, the traction rope installation parts 310 in the traction rope installation part combination 300 are arranged adjacently. For example, the traction rope installation part combination 300 includes two traction rope installation parts 310, which are arranged radially opposite and close to each other. In this way, the bending degree of the part of the curved pipe 100 with the opposite traction rope installation parts 310 can be kept similar during the traction of the traction ropes. Of course, there can be other numbers of traction rope installation parts 310 in one traction rope installation part combination 300, such as three, four, or five, etc.

[0060] In some embodiments, in the axial direction of the curved pipe 100, the traction rope installation part 310 is arranged corresponding to one slit 210 on the radially opposite side. In this way, the distribution position of the traction rope installation part 310 and the slit 210 can be more reasonable. Since the cross section of the curved pipe 100 is circular, the slit 210 occupies the cross section size of the curved pipe 100. In the circumferential direction of the curved pipe 100, the part opposite to the slit 210 is not occupied by the slit 210, so it can be used to arrange the traction rope installation part 310.

[0061] In some embodiments, as shown in FIG. 6, the curved pipe 100 has a plurality of axially connected curved units 400, and the adjacent curved units 400 are connected through a joint part 410. The traction rope installation part 310 is arranged corresponding to the adjacent joint part 410. On this basis, the traction rope installation part 310 is arranged on the adjacent joint part 410, so that the distribution of the traction rope installation part 310 is closer. When the curved pipe 100 is bent in two opposite directions, the bending performance can be further kept similar.

[0062] In some embodiments, the distribution path of the slit 210 is opposite to the extension path of the traction rope, so that, during the process of the operator manipulating the traction rope to pull the active bending section 600, the bending tube 100 bends along with the active bending section 600, and the stress distribution path of the bending tube 100 is opposite to the distribution path of the slit 210 during the bending, so that the bending tube 100 is more likely to bend under the action of the slit 210.

[0063] For example, the distribution path of the slit 210 is distributed in the axial direction of the bending tube 100 opposite to the extension path of the traction rope, so that, during the process of the operator manipulating the traction rope to pull the active bending section 600, the bending tube 100 bends along with the active bending section 600, and the stress distribution path of the bending tube 100 is opposite to the distribution path of the slit 210 during the bending, so that the slit 210 is less likely to be damaged due to excessive stress, and the bending tube 100 can also bend normally.

[0064] Please refer to FIGS. 1-13, in the second aspect, some embodiments of the present application also provide a passive bending section, which comprises the bending tube 100 in any of the foregoing aspects. Thus, the passive bending section of the embodiments of the present application has the beneficial effects of the foregoing bending tube 100, which will not be described here.

[0065] For example, in combination with FIGS. 7 and 8, the passive bending section further comprises a main hose 500 connected to the proximal end of the bending tube 100, and the rigidity of the main hose 500 is greater than that of the proximal end of the bending tube 100. For example, the end of the main hose 500 away from the bending tube 100 is connected to the operating handle of the endoscope, so that, during the process of the operator manipulating the traction rope to pull, the bending tube 100 can follow the action of the active bending section 600, and the bending amplitude of the main hose 500 is small due to the greater rigidity, so that the operability of the main hose 500 close to the operating handle is higher.

[0066] In some embodiments, in order to improve the bending degree of the insertion part 700, a plurality of slits 210 can also be arranged along the axis of the main hose 500, so that the insertion part 700 can adapt to more tortuous human body cavities. Of course, the arrangement of the slits 210 on the main hose 500 can also be set according to the arrangement of the slits 210 on the bending tube 100, which has the same effect, which will not be described here.

[0067] For example, in combination with FIGS. 9 and 10, the proximal end of the bending tube 100 has a plug-in part 110 provided with a joint slit 1110, and the distal end of the main hose 500 has a butt joint section 510 which is in interference fit with the part of the plug-in part 110 provided with the joint slit 1110. For example, the outer diameter of the butt joint section 510 is greater than or equal to the inner diameter of the plug-in part 110.

[0068] On this basis, when connecting the curved tube 100 and the main hose 500, the butt joint section 510 can be directly inserted into the inner cavity of the insertion part 110. Since the insertion part 110 is provided with the joint seam 1110, the rigidity of the part of the insertion part 110 with the joint seam 1110 is small, and in the process of inserting the butt joint section 510, the outer wall of the butt joint section 510 can directly push the part of the insertion part 110 with the joint seam 1110 to avoid in the direction away from the butt joint section 510, so that the butt joint section 510 can smoothly enter the inner cavity of the insertion part 110, and finally make the butt joint section and the butt joint section 510 realize interference fit. Moreover, after the butt joint section 510 and the insertion part 110 are inserted in place, the part of the butt joint section 510 inserted can react on the part of the insertion part 110 with the joint seam 1110 to improve the rigidity of the part of the insertion part 110 with the joint seam 1110. In this way, when the operator controls the insertion part 700 to rotate, since the rigidity of the connection part of the two is improved, the coaxiality of the connection part of the insertion part 110 and the butt joint section 510 is further improved, and the connection part of the insertion part 110 and the butt joint section 510 can smoothly and synchronously rotate.

[0069] In some embodiments, as shown in FIG. 11, the end of the joint seam 1110 away from the butt joint section 510 and the end of the gap 210 are distributed in the axial direction of the passive bending section. Since the end of the joint seam 1110 and the end of the gap 210 are both stress areas, the purpose of such arrangement is to avoid the stress area around the end of the joint seam 1110 from the stress area around the end of the gap 210, which is beneficial to improve the damage resistance and rigidity of the curved tube 100 after the joint seam 1110 is arranged, so that the curved tube 100 can maintain good coaxiality when the insertion part 700 rotates.

[0070] Please refer to FIGS. 1-13, in a third aspect, some embodiments of the present application further provide an insertion part 700, which comprises the passive bending section mentioned in any of the preceding schemes.

[0071] Please refer to FIGS. 1-13, in a fourth aspect, some embodiments of the present application further provide an endoscope, which comprises the insertion part 700 mentioned in any of the preceding schemes.

[0072] The endoscope involved in the embodiments of the present application can be a bronchoscope, a nephroscope, an esophagoscope, a gastroscope, a colonoscope, an otoscope, a nasoscope, a mouth mirror, a laryngoscope, a colposcope, a laparoscope, an arthroscope, etc., and the type of the endoscope is not specifically limited in the embodiments of the present application.

[0073] The above merely describes the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which shall be covered in the protection scope of the present application.

Claims

1. A curved tube for a passive bending section of an endoscope, characterized in that, The distal end of the curved tube (100) is used to connect the active bending section (600) of an endoscope, the curved tube (100) comprises slits (210) which penetrate to the inside of the curved tube (100), the slits (210) are arranged at least on the part of the curved tube (100) close to the distal end, and the slits (210) are arranged in multiple along the axial direction of the curved tube (100); The radial depth of each slit (210) gradually decreases in the direction from the distal end to the proximal end of the curved tube (100).

2. The curved tube of claim 1, wherein, The multiple slits (210) comprise multiple slit groups (200) arranged in the axial direction of the curved tube (100), wherein the radial depth of the slits (210) in the slit group (200) closer to the distal end of the curved tube (100) is greater than the radial depth of the slits (210) in the slit group (200) closer to the proximal end of the curved tube (100); Alternatively, in the direction from the distal end to the proximal end of the curved tube (100), the radial depth of one of the adjacent slits (210) on the same side of the curved tube (100) is greater than the radial depth of the other adjacent slit (210).

3. The curved tube of claim 2, wherein, The curved tube (100) has a traction rope mounting part combination (300) arranged in the axial direction of the curved tube (100); The traction rope mounting part combination (300) comprises traction rope mounting parts (310) arranged in radial opposition on the curved tube (100), and the traction rope mounting parts (310) in the traction rope mounting part combination (300) are arranged in proximity; The adjacent traction rope mounting part combinations (300) are arranged in axial spacing on the curved tube (100), and multiple slits (210) are arranged in the spacing path of the adjacent traction rope mounting part combinations (300).

4. The curved tube of claim 3, wherein, In the axial direction of the curved tube (100), the traction rope mounting parts (310) are arranged in correspondence with one slit (210) on the radially opposite side; And / or, the curved tube (100) has multiple axially connected curved units (400), and the adjacent curved units (400) are connected through a joint (410), and the traction rope mounting parts (310) are arranged in correspondence with the adjacent joints (410).

5. The curved tube of claim 3, wherein, The distribution path of the slits (210) is opposite to the extension path of the traction rope; Alternatively, the distribution path of the slits (210) and the extension path of the traction rope are distributed in axial displacement on the curved tube (100).

6. A passive bend segment, characterized by The curved tube (100) comprises the curved tube (100) according to any one of claims 1-5.

7. The passive bend segment of claim 6, wherein, The passive bending section further comprises a main hose (500) connected to the proximal end of the curved tube (100), and the rigidity of the main hose (500) is greater than the rigidity of the proximal end of the curved tube (100).

8. The passive bend segment of claim 7, wherein, The proximal end of the curved pipe (100) has a splicing part (110) provided with a joint seam (1110), and the distal end of the main hose (500) has a butt joint section (510) in interference fit with the part of the splicing part (110) provided with the joint seam (1110); The end of the joint seam (1110) away from the butt joint section (510) is distributed in the axial direction of the passive curved section away from the end of the gap (210).

9. An insertion portion characterized by: The passive curved section according to any one of claims 7 or 8.

10. An endoscope characterized by comprising: The splicing part (700) according to claim 9. The passive curved section according to any one of claims 7 or 8.

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