Guide tube sheath and endoscope assembly

Abstract

The guiding tube sheath comprises a guiding tube, a lens seat and a light-transmitting lens, a containing cavity is formed in the lens seat, the far end of the lens seat is provided with a first opening communicated with the containing cavity and a first end face surrounding the first opening, and a limiting step is arranged on the cavity wall of the containing cavity in a protruding mode; at least part of the far end of the limiting step and the first end face form a supporting structure, and the light-transmitting lens is fixed to the supporting structure and seals the first opening. On the scene that the overall outer diameter of the guide tube sheath is not increased or the requirement for the overall outer diameter of the guide tube sheath is smaller, the connection area between the light-transmitting lens and the lens seat can be effectively increased by means of matching of the limiting step in the far end of the lens seat and the end face of the far end of the lens seat, and the connection strength between the light-transmitting lens and the lens seat is enhanced; therefore, a series of problems such as lens falling or influence on endoscope imaging caused by unstable connection of the light-transmitting lens are avoided; and meanwhile, support can be provided for conveniently, quickly and stably realizing the connection between the lens seat and the guide tube.

Description

Technical Field

[0001] This application relates to the field of medical device technology, specifically to a guide tube sheath and endoscope assembly. Background Technology

[0002] In clinical medicine, using endoscopes to explore, examine, and treat the body's natural cavities is currently the most commonly used minimally invasive diagnostic and treatment method, causing less damage to patients. Traditional endoscopes need to be reused after sterilization, while disposable endoscopes solve the problems of cross-infection and the need for repeated sterilization associated with traditional endoscopes. However, disposable endoscopes are more expensive, which is one of the important factors limiting their rapid development and widespread application.

[0003] In light of this, some alternative solutions exist that use disposable guide tube sheaths in conjunction with endoscopes to replace disposable endoscopes. For example, the portion of the disposable guide tube sheath inserted into the body is a closed design, and the distal end of the lens mount of the disposable guide tube sheath is sealed with a lens (e.g., a transparent glass cover). The distal end of the endoscope tube has a viewing window that allows light to pass through. After the endoscope tube is inserted into the disposable guide tube sheath, it will not come into contact with the human body. After the surgery is completed, the disposable guide tube sheath is discarded, while the endoscope can be reused. This reduces the requirements for endoscope sterilization and also reduces costs.

[0004] However, the connection of the lens in the disposable guide tube sheath is not stable. When doctors repeatedly operate to attach and maintain the viewing window at the distal end of the endoscope tube with the lens at the distal end of the guide tube sheath lens mount, the lens can easily fall off due to excessive force because the operating force is difficult to control. Utility Model Content

[0005] The main technical problem addressed by this application is to provide a guide tube sheath and an endoscope assembly using the guide tube sheath, which can improve the stability and reliability of the guide tube sheath structure.

[0006] According to a first aspect, one embodiment provides a guide tube sheath, comprising:

[0007] A guide tube for inserting an endoscope into the guide tube sheath;

[0008] The lens mount has a receiving cavity inside. The distal end of the lens mount has a first opening communicating with the receiving cavity and a first end face surrounding the first opening. The cavity wall of the receiving cavity is provided with a limiting step. At least a portion of the distal end of the limiting step forms a support structure with the first end face. The proximal end of the lens mount has a second opening communicating with the receiving cavity. The second opening is used to insert at least a portion of the guide tube into the receiving cavity.

[0009] And a light-transmitting lens, which is fixed to the support structure and closes the first opening.

[0010] In one embodiment, the thickness of the support structure is between 0.2 mm and 0.4 mm in a direction perpendicular to the geometric center line of the first opening.

[0011] In one embodiment, the limiting step is enclosed around the geometric center line of the first opening.

[0012] In one embodiment, the distal end face of the limiting step is flush with the first end face to form the support structure.

[0013] In one embodiment, the guide tube includes a first guide tube for inserting the endoscope, the distal end of the first guide tube being inserted into the receiving cavity, and the distal end face of the first guide tube abutting against the proximal end face of the limiting step.

[0014] In one embodiment, the wall thickness of the first guide inner tube is equal to the thickness of the limiting step in a direction perpendicular to the geometric center line of the first opening.

[0015] In one embodiment, the guide tube further includes a guide outer tube, the distal end of the first guide inner tube extends from the guide outer tube, and the proximal end of the lens mount also has a second end face surrounding the second opening, the distal end face of the guide outer tube abutting and fixed against the second end face.

[0016] In one embodiment, the guide tube further includes a second inner guide tube, which is arranged parallel to the first inner guide tube and passes through the outer guide tube; the lens mount also has a first channel that passes through the lens mount, which is arranged parallel to and independent of the accommodating cavity; wherein, the distal end of the second inner guide tube is inserted into the first channel, or the second inner guide tube is sealed and connected to the first channel.

[0017] In one embodiment, the light-transmitting lens is a flexible lens, and the flexible lens is attached and fixed to the support structure.

[0018] According to a second aspect, one embodiment provides an endoscope assembly including an endoscope and the guide tube sheath described in the first aspect.

[0019] The guide tube sheath according to the above embodiment includes a guide tube, a lens mount, and a transparent lens. The lens mount has an internal accommodating cavity. The distal end of the lens mount has a first opening communicating with the accommodating cavity and a first end face surrounding the first opening. A limiting step protrudes from the cavity wall of the accommodating cavity. At least a portion of the distal end of the limiting step forms a supporting structure with the first end face. The transparent lens is fixed to the supporting structure and closes the first opening. In scenarios where the overall outer diameter of the guide tube sheath is not increased or a smaller overall outer diameter is required, the cooperation between the limiting step inside the distal end of the lens mount and the distal end face of the lens mount can effectively increase the connection area between the transparent lens and the lens mount, enhancing the connection strength between the transparent lens and the lens mount. This avoids a series of problems such as lens detachment or impact on endoscopic imaging due to unstable lens connection. Simultaneously, it also provides support for convenient, quick, and stable connection between the lens mount and the guide tube. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structural assembly of a guide tube sheath according to one embodiment.

[0021] Figure 2 A schematic diagram of the exploded structure of the guide tube sheath in one embodiment (I).

[0022] Figure 3 A schematic diagram (II) showing the structural breakdown of the guide tube sheath in one embodiment.

[0023] Figure 4 This is a schematic cross-sectional view of the guide tube sheath in one embodiment (I).

[0024] Figure 5 This is a schematic cross-sectional view of the guide tube sheath after omitting the guide tube in one embodiment.

[0025] Figure 6 This is a schematic cross-sectional view of the lens mount in a guide tube sheath according to one embodiment.

[0026] Figure 7 This is a cross-sectional structural schematic diagram (II) of a guide tube sheath according to one embodiment.

[0027] Figure 8 This is a cross-sectional structural schematic diagram of an endoscope assembly according to one embodiment.

[0028] In the picture:

[0029] 10. Guide tube; 11. Outer guide tube; 12. First inner guide tube; 13. Second inner guide tube; 20. Lens mount; 20a. Support platform; 21. Receiving cavity; 22. First opening; 24. Second opening; 25. Limiting step; 26. First channel; 27. Second end face; 30. Transmitting lens; 40. Lens tube; 50. Lens. Detailed Implementation

[0030] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments. Similar elements in different embodiments are referred to by related similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of the present application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to the present application are not shown or described in the specification. This is to avoid obscuring the core parts of the present application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0031] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0032] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0033] In existing disposable guide tube sheaths, the lens is usually fixed to the distal end face of the lens mount by sealing the distal opening of the lens mount. In scenarios where the outer diameter of the lens mount cannot be increased (such as in the design of ultra-fine endoscopes), the size requirements of the guide tube sheath fitted outside the endoscope are usually very high, which severely limits the connection area or connection thickness between the lens and the end face of the lens mount. For example, the connection thickness between the lens and the lens mount in the radial direction of the guide tube sheath is usually only 0.15mm. During the use of the guide tube sheath and the endoscope, problems such as unstable lens connection or even lens detachment can easily occur.

[0034] The endoscope assembly provided in this application, by setting a limiting step inside the lens mount of the guide tube sheath, can effectively increase the connection area between the light-transmitting lens of the guide tube sheath and the lens mount without increasing the outer diameter of the guide tube sheath or in scenarios where the overall outer diameter of the guide tube sheath is required to be smaller. This achieves a stable and reliable fixation of the light-transmitting lens and the lens mount, avoiding a series of problems such as the light-transmitting lens falling off due to unstable lens connection.

[0035] To describe the endoscope assembly provided in this application more clearly and in detail, the terms "proximal" and "distal" are defined for the relevant components based on their distance from the operator during use. For example, the distal end of an endoscope refers to the end furthest from the endoscope handle, while the proximal end refers to the end where the endoscope handle is located. Similarly, the proximal end of a guide tube sheath refers to the end into which the endoscope is inserted, while the distal end refers to the end inserted into the human body and furthest from the endoscope handle. Here, "end" refers to the area at the end of a component, which can be understood as a region of a certain length at the end, and is not limited to the end face.

[0036] Please see Figures 1 to 8 This application provides an endoscope assembly including a reusable endoscope and a disposable guide sheath; wherein, please refer to Figures 1 to 3 The guide tube sheath includes a guide tube 10, a lens mount 20 at the distal end of the guide tube 10, a light-transmitting lens 30 at the distal end of the lens mount 20, and other functional components as needed; please refer to Figure 8 The endoscope includes an endoscope handle, a tube 40 for inserting a guide tube sheath, a lens 50 located at the distal end of the tube 40, and other functional components as needed. The endoscope and guide tube sheath are assembled by inserting the endoscope tube 40 into the guide tube sheath via the guide tube 10, and by having the endoscope lens 50 abut against and conform to the light-transmitting lens 30, thus making the endoscope assembly ready for use.

[0037] The following mainly introduces the guide tube sheath and its related structures. Other components of the endoscope assembly can be referred to in the existing technology and will not be described in detail here.

[0038] Please see Figure 2 and Figure 3 as well as Figures 5 to 7 The lens mount 20 has a receiving cavity 21, a first opening 22, a first end face (not shown in the figure), a second opening 24, and a limiting step 25. The receiving cavity 21 is formed inside the lens mount 20. The first opening 22 penetrates the distal end face of the lens mount 20 and connects to the receiving cavity 21. The second opening 24 penetrates the proximal end face of the lens mount 20 and connects to the receiving cavity 21. The first end face can be understood as an annular end face surrounding the first opening 21 on the distal surface of the lens mount 20. Based on the communication relationship between the receiving cavity 21, the first opening 22, and the second opening 24, a channel penetrating from the proximal to the distal end of the lens mount 20 can be formed inside the lens mount 20. At least a portion of the distal end of the guide tube 10 can be inserted into the receiving cavity 21 through the second opening 24.

[0039] Please see Figure 6The limiting step 25 protrudes from the cavity wall of the receiving cavity 21 in a direction perpendicular to the geometric center line of the first opening 22, and the limiting step 25 is located at the far end of the receiving cavity 21 or inside the first opening 22; at least part of the structure at the far end of the limiting step 25 can cooperate with the first end face to form a support structure for supporting and fixing the light-transmitting lens 30.

[0040] Please see Figure 2 , Figure 4 and Figure 7 The transparent lens 30 is attached and fixed to the support structure (e.g., support platform 20a) in a manner that covers the first opening 22. This can be achieved through methods such as laser welding or other thermal fusion methods, or physical or chemical bonding. In this way, the cooperation between the transparent lens 30 and the support structure seals the second opening 22. After the endoscope tube 40 is inserted via the guide tube 10, the transparent lens 30 blocks the endoscope lens 50, thus confining the endoscope lens 50 within the lens mount 20. Furthermore, the attachment between the transparent lens 30 and the endoscope lens 50 provides support for the endoscope to collect ambient light and form an image.

[0041] In some embodiments, please refer to Figure 2 , Figure 5 and Figure 6 The distal end face of the limiting step 25 is flush with the first end face, thereby forming a support platform 20a surrounding the first opening 22. At this time, the support platform 20a can be regarded as a support structure for supporting and fixing the light-transmitting lens 30. By stacking and attaching the light-transmitting lens 30 onto the support platform 20a, the light-transmitting lens 30 can be conveniently and quickly fixed to the lens mount 20 by means of heat fusion, welding, etc.

[0042] In other embodiments, please refer to Figure 7 The distal end face of the limiting step 25 protrudes beyond the first end face. At this time, the distal end face of the limiting step 25 and the side surface adjacent to the first end face can together with the first end face form a support structure for supporting and fixing the light-transmitting lens 30. Thus, by attaching and fixing the light-transmitting lens 30 to the support structure in a manner that surrounds and covers the first opening 22, a larger connection area can be formed between the light-transmitting lens 30 and the lens mount 20, ensuring the stability of the connection of the light-transmitting lens 30.

[0043] Therefore, by setting a limiting step 25 inside the distal end of the lens mount 20, the connection area between the light-transmitting lens 30 and the lens mount 20 can be effectively increased by utilizing the cooperation between the limiting step 25 and the first end face without increasing the overall outer diameter of the lens mount 20 (or the guide tube sheath). This ensures the connection strength between the two and avoids a series of problems such as the light-transmitting lens 30 falling off and the endoscope imaging being affected by the unstable connection of the light-transmitting lens 30 when the guide tube sheath is used with the endoscope. At the same time, forming a limiting step 25 inside the distal end of the lens mount 20 does not require a significant change to the structure of the lens mount 20, and the manufacturing process is simple.

[0044] It should be noted that the far end face of the limiting step 25 mentioned in this article is flush with the first end face, which can be an ideal state of absolute flushing. For example, after the lens mount 20 is formed (such as integral injection molding), the plane where the support platform 20a is located is perpendicular to the geometric center line of the first opening 22, and the support platform 20a is an annular plane surrounding the first opening 22. At this time, the far end face and the first end face of the limiting step 25 can be understood as the inner ring area and the outer ring area of ​​the support platform 20a, respectively. Of course, being flush can also mean being approximately flush. During the actual manufacturing process of the lens mount 20, there may be a slight deviation between the distal end face of the limiting step 25 and the first end face. For example, the tapered slope of the support platform 20a surrounding the first opening 22, or one of the distal end face and the first end face of the limiting step 25 protruding from the other. However, this deviation, which does not affect the connection of the light-transmitting lens 30 or the overall outer diameter of the lens mount 20 (or the guide tube sheath), can also indicate that the distal end face of the limiting step 25 is flush with the first end face.

[0045] In some embodiments, please refer to Figure 5 The thickness D1 of the support structure in the direction perpendicular to the centerline of the first opening 22 is between 0.2mm and 0.4mm; for example, the thickness of the annular support platform 20a formed by the distal end face of the limiting step 25 being flush with the first end face is between 0.2mm and 0.4mm. For example, for ease of distinction and description, the channel formed inside the lens mount 20 based on the communication relationship between the accommodating cavity 21, the first opening 22, and the second opening 24 is defined as the second channel; in some existing guide tube sheaths, the wall thickness of the second channel is usually 0.15mm, which also results in a connection thickness of only 0.15mm between the light-transmitting lens 30 and the end face of the lens mount 20. However, in this application, by setting the limiting step 25 inside the distal end of the second channel, the connection thickness between the light-transmitting lens 30 and the lens mount 20 can reach between 0.2mm and 0.4mm (e.g., 0.3mm), which is sufficient to ensure that the light-transmitting lens 30 can be firmly fixed on the lens mount 20.

[0046] Thus, by limiting the thickness of the support structure or the limiting step 25, the guide tube sheath can be assembled and formed by adjusting the position of the distal end of the guide tube 10 inside the lens mount 20 (i.e., the receiving cavity 21) without changing the outer diameter of the guide tube 10 or the endoscope. This provides support for convenient and quick assembly and disassembly of the guide tube sheath and the endoscope. It should be noted that, taking the annular support platform 20a as an example, the thickness D1 of the support structure refers to the distance between the outer and inner edges of the support platform 20a.

[0047] In some embodiments, please refer to Figure 2 and combined Figure 6 The limiting step 25 is arranged within the receiving cavity 21 around the geometric center line of the first opening 22, so that a relatively complete support structure (e.g., support platform 20a) is formed around the first opening 22 based on the cooperation between the distal end face of the limiting step 25 and the first end face. In this way, the diameter of the first opening 22 can be reduced from the inside of the lens mount 20 by using the limiting step 25. While effectively increasing the connection area between the light-transmitting lens 30 and the end face of the lens mount 20, the limiting step 25 can also block the part of the guide tube 10 inserted into the receiving cavity 21. This prevents the guide tube 10 from contacting and pressing against the light-transmitting lens 30 when the assembly of the lens mount 20 and the light-transmitting lens 30 is assembled with the guide tube, thus ensuring the stability of the connection of the light-transmitting lens 30.

[0048] In other embodiments, the limiting steps 25 may also adopt other suitable structural forms, such as multiple limiting steps 25 arranged at intervals around the geometric center line of the first opening 22 in the receiving cavity 21 or the first opening 22; all such details will not be elaborated here.

[0049] In some embodiments, please refer to Figures 2 to 4 The guide tube 10 is a multi-lumen combination tube, which includes an outer guide tube 11, a first inner guide tube 12, and a second inner guide tube 13. The first inner guide tube 12 and the second inner guide tube 13 are installed in parallel inside the outer guide tube 11, and the distal end of the first inner guide tube 12 extends out of the outer guide tube 11 from the distal opening of the outer guide tube 11.

[0050] Correspondingly, the lens mount 20 also has a first channel 26 and a second end face 27. The first channel 26 is arranged through the lens mount 20 in the direction from the proximal end to the distal end. The first channel is arranged in parallel with the aforementioned second channel and is independent of each other. The second end face 27 refers to the end face of the lens mount 20 that is proximal to the second opening 24 and enclosed by the first channel 26.

[0051] With the guide tube sheath assembled, the distal end face of the guide outer tube 11 is abutted and fixed to the second end face 27, for example, by thermal fusion welding such as laser welding, or by chemical or physical bonding. By connecting and fixing the guide outer tube 11 to the lens mount 20, an outer protection is formed for the first guide inner tube 12 and the second guide inner tube 13. Based on the structural feature that the distal end of the first guide inner tube 12 protrudes or extends beyond the guide outer tube 11, the first guide inner tube 12 is inserted into the receiving cavity 21 through the second opening 24, and the distal end face of the first guide inner tube 12 abuts against the proximal end face of the limiting step 25. This allows the endoscope to be inserted into the lens mount 20 using the first guide inner tube 12, keeping the endoscope lens 50 in contact with the light-transmitting lens 30.

[0052] The second guide tube 13 is inserted into the first channel 26, or the second guide tube 13 is sealed and connected to the first channel 26 (for example, the end face of the second guide tube 13 located at the proximal end of the lens mount 20 and surrounding the port of the first channel 26 is abutted and fixed to the distal end face of the second guide tube 13); based on the connection between the second guide tube 13 and the first channel 26, it can be used as an injection channel, instrument channel, etc.

[0053] Therefore, by fitting and fixing the distal end face of the outer guide tube to the second end face 27, without increasing the overall outer diameter of the guide tube sheath, the first inner guide tube 12 can be restricted to a position where its distal end face abuts against the proximal end face of the limiting step 25. This also allows for convenient, quick, and stable fixation of the lens mount 20 and the light-transmitting lens 10 assembly to the guide tube 10, reducing the manufacturing difficulty of the guide tube sheath. Furthermore, the multi-cavity combined tube design of the guide tube enriches the practical functions of the guide tube sheath and meets application needs.

[0054] In some embodiments, please refer to Figure 4 and Figure 5 In a direction perpendicular to the geometric center line of the first opening 22, the wall thickness of the first guide inner tube 12 is set to be less than or equal to the thickness D2 of the limiting step 25. For example, the thickness of the limiting step 25 and the wall thickness of the first guide inner tube 12 can both be 0.15 mm.

[0055] With the distal end face of the first guide tube 12 abutting against the proximal end face of the limiting step 25, the space enclosed by the limiting step 25 effectively extends the tube space of the first guide tube 12 within the lens mount 20 to the position of the light-transmitting lens 30. Thus, by utilizing the compatibility between the thickness D2 of the limiting step 25 and the wall thickness of the first guide tube 12, it is possible to ensure that the endoscope can be smoothly inserted into or removed from the guide tube sheath without adjusting (e.g., reducing) the diameter of the first guide tube 12 and the outer diameter of the endoscope. At the same time, the proximal end face of the limiting step 25 can be completely fitted with the distal end face of the first guide tube 12 to securely restrict the second guide tube 12 within the lens mount 20.

[0056] In some embodiments, the guide tube 10 may also adopt other forms of multi-cavity tube structure. For example, the guide tube 10 has an integrally formed tube body with multiple cavities arranged along the axial direction of the tube body. The opening of one of the cavities can extend beyond the distal end of the tube body to serve as the first guide inner tube 12, while the other cavities can serve as the second guide inner tube 13. When the assembly of the lens mount 20 and the light-transmitting lens 30 is assembled with the guide tube 10, the distal end face of the tube body is abutted and fixed to the second end face 27 of the lens mount 20, while the end face of the cavity extending beyond the tube body abuts against the proximal end face of the limiting step 25.

[0057] In other embodiments, the guide tube 10 may have only the first inner guide tube 12, or it may be composed of the outer guide tube 11 and the first inner guide tube 12; all such embodiments will not be elaborated here.

[0058] In some embodiments, please refer to Figure 8 The light-transmitting lens 30 is a flexible lens. For example, a flexible lens can be a flexible transparent film made of materials such as TPU, PVC, PE, EVA, PU, ​​PO, and NFEP, giving it the ability to undergo elastic deformation. On the one hand, by utilizing the elastic deformation characteristic of the flexible transparent film, it can adapt to the shape of the supporting structure, which is conducive to making full use of the connection area between the two, thereby enhancing the stability and reliability of the bonding and fixation between the flexible transparent film and the supporting structure.

[0059] On the other hand, when the guide tube sheath is used in conjunction with the endoscope, when the lens 50 of the endoscope presses against the flexible transparent membrane, it will cause the flexible transparent membrane to undergo a certain deformation and displacement. Under the action of the elastic force of the flexible transparent membrane, the flexible transparent membrane and the lens 50 of the endoscope will adaptively fit tightly, which can reduce or even eliminate the gap between the two, which is beneficial to improving the imaging quality of the endoscope.

[0060] In other embodiments, the light-transmitting lens 30 can also be a flexible lens in the form of a plastic film, in which case the light-transmitting lens 30 is only flexible and not elastic; the light-transmitting lens 30 can also be a rigid sheet, such as a rigid film, a glass sheet, etc. Under the premise that the overall outer diameter of the lens mount 20 is smaller, the connection area between the light-transmitting lens 30 and the lens mount 20 can also be increased based on the limiting step 25, so as to ensure the connection strength between the two.

[0061] The above examples illustrate this application only to aid understanding and are not intended to limit its scope. Those skilled in the art to which this application pertains can make various simple deductions, modifications, or substitutions based on the ideas presented.

Claims

1. A guide tube sheath, characterized in that, include: A guide tube for inserting an endoscope into the guide tube sheath; The lens mount has a receiving cavity inside. The distal end of the lens mount has a first opening communicating with the receiving cavity and a first end face surrounding the first opening. The cavity wall of the receiving cavity is provided with a limiting step. At least a portion of the distal end of the limiting step forms a support structure with the first end face. The proximal end of the lens mount has a second opening communicating with the receiving cavity. The second opening is used to insert at least a portion of the guide tube into the receiving cavity. And a light-transmitting lens, which is fixed to the supporting structure and closes the first opening.

2. The guide tube sheath as described in claim 1, characterized in that, The thickness of the support structure is between 0.2 mm and 0.4 mm in a direction perpendicular to the geometric center line of the first opening.

3. The guide tube sheath as described in claim 1, characterized in that, The limiting step surrounds the geometric center line of the first opening.

4. The guide tube sheath as described in claim 1, characterized in that, The distal end face of the limiting step is flush with the first end face to form the support structure.

5. The guide tube sheath as described in claim 1, characterized in that, The guide tube includes a first guide tube for inserting the endoscope, the distal end of the first guide tube being inserted into the receiving cavity, and the distal end face of the first guide tube abutting against the proximal end face of the limiting step.

6. The guide tube sheath as described in claim 5, characterized in that, In a direction perpendicular to the geometric center line of the first opening, the wall thickness of the first guide inner tube is less than or equal to the thickness of the limiting step.

7. The guide tube sheath as described in claim 5, characterized in that, The guide tube also includes a guide outer tube, the distal end of the first guide inner tube extends from the guide outer tube, and the proximal end of the lens mount also has a second end face surrounding the second opening, with the distal end face of the guide outer tube abutting and fixed against the second end face.

8. The guide tube sheath as described in claim 7, characterized in that, The guide tube further includes a second inner guide tube, which is arranged parallel to the first inner guide tube and passes through the outer guide tube; the lens mount also has a first channel that passes through the lens mount, which is arranged parallel to and independent of the accommodating cavity; wherein, the distal end of the second inner guide tube is inserted into the first channel, or the second inner guide tube is sealed and connected to the first channel.

9. The guide tube sheath as described in any one of claims 1-8, characterized in that, The light-transmitting lens is a flexible lens, and the flexible lens is attached and fixed to the supporting structure.

10. An endoscope assembly, characterized in that, Includes an endoscope and a guide tube sheath as described in any one of claims 1-9.

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