Dilator, ureteral access sheath and endoscope assembly

Abstract

The present application relates to the technical field of medical devices. Disclosed are a dilator, a ureteral access sheath and an endoscope assembly. The dilator disclosed in the present application is for use in a ureteral access sheath. The dilator comprises a dilation tube and a clamp, wherein the clamp comprises a base and at least two clamping arms distributed in the circumferential direction of the base, and the clamp can be connected to the proximal end of a sheath of the ureteral access sheath by means of the clamping arms; and the base has a mounting hole, the proximal end of the dilation tube passes through the mounting hole, and in both the axial direction and the circumferential direction of the dilator, the proximal end of the dilation tube is connected to the base in a clamped and location fit manner. The solution can at least improve the smoothness of an insertion action of the ureteral access sheath.

Description

dilator, ureteral sheath and endoscope assembly Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a dilator, ureteral sheath, and endoscope assembly. Background Technology

[0002] Ureteral sheaths are used in urological endoscopic examinations or surgeries. They can create an examination / operative channel within the urinary system to assist endoscopes and surgical instruments in passing through cavities such as the urethra and ureter, thereby improving the effectiveness and safety of examinations and treatments.

[0003] In related technologies, the ureteral sheath includes a sheath tube and a dilator. During the insertion of the ureteral sheath, the dilator uses its distal conical tip to open the cavity wall to facilitate the insertion of the sheath tube. The dilator is then withdrawn, thus establishing a working channel for the nephroscope or ureteroscope. However, in practice, even with the use of a dilator, the insertion process of the ureteral sheath is still not smooth enough. Utility Model Content

[0004] This application provides a dilator, a ureteral sheath, and an endoscope assembly, which can at least improve the smoothness of ureteral sheath insertion.

[0005] In one aspect, embodiments of this application provide a dilator for a ureteral sheath.

[0006] The dilator includes a dilator tube and a clamp, wherein: the clamp includes a base and at least two clamping arms distributed circumferentially along the base, and the clamp can be connected to the proximal end of the ureteral sheath through the clamping arms; the base has a mounting hole, the proximal end of the dilator tube passes through the mounting hole, and the proximal end of the dilator tube is engaged and positioned with the base in both the axial and circumferential directions of the dilator.

[0007] Secondly, an embodiment of this application provides a ureteral sheath, including a sheath tube and the dilator described in the first aspect of this application, wherein the dilator tube can be inserted into the sheath tube, and the clamp can be connected to the proximal end of the sheath tube via a clamping arm.

[0008] Thirdly, embodiments of this application provide an endoscope assembly, including an endoscope and the ureteral sheath described in the second aspect of embodiments of this application, wherein the insertion portion of the endoscope can be inserted into the sheath.

[0009] The technical solution adopted in the embodiments of this application can achieve the following beneficial effects:

[0010] In the dilator disclosed in this application embodiment, the proximal end of the dilator tube and the base of the clamp are simultaneously engaged and positioned along the circumference and axial direction of the dilator. This arrangement ensures that the dilator tube and the base are relatively fixed along the circumference of the dilator. During the insertion of the ureteral sheath, the dilator of this application embodiment can be rotated by rotating either the clamp or the dilator tube. This allows the distal head of the dilator to rotate, and by utilizing its relative misalignment with the cavity wall, the frictional resistance is changed from sliding friction to rolling friction, thereby alleviating the insertion obstruction problem and improving the smoothness of the ureteral sheath insertion.

[0011] In addition, because the expansion tube and the clamp are positioned and fitted together along the circumference of the expander, even if the proximal end of the expansion tube is hidden inside the base of the clamp, the entire expander can still be rotated by rotating the clamp. Attached Figure Description

[0012] The accompanying drawings, which are provided to further illustrate this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application.

[0013] In the attached diagram:

[0014] Figure 1 is a schematic diagram of the structure of the ureteral sheath when the dilator is separated from the sheath, as disclosed in some embodiments of this application;

[0015] Figure 2 is a schematic diagram of the installation of the expander disclosed in some embodiments of this application;

[0016] Figure 3 is a schematic diagram of the structure of the expander disclosed in some embodiments of this application;

[0017] Figure 4 is a schematic diagram of the structure of the sheath disclosed in some embodiments of this application;

[0018] Figure 5 is a schematic diagram of the structure of the ureteral sheath disclosed in some embodiments of this application when the dilator and the sheath are engaged;

[0019] Figures 6 and 7 are cross-sectional views of the ureteral sheath from different perspectives in some embodiments of this application.

[0020] Explanation of reference numerals in the attached figures:

[0021] 100-Expander

[0022] 110-Expansion tube, 111-First tube body, 112-Adapter, 112a-First positioning groove, 120-Clamp, 121-Base, 121a-Mounting hole, 121b-First positioning rib, 121c-Second positioning rib, 121d-Abutting surface, 122-Clamping arm, 122a-Positioning recess, 122b-Guide groove, 122c-First guide surface

[0023] 200-Sheath

[0024] 210-Second tube body, 220-Connecting seat, 221-Positioning protrusion, 222-Second guide surface. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0026] In the various embodiments of this application, "proximal end" and "distal end" refer to the position of the endoscope and its components and accessories (such as ureteral sheath) relative to the user in the usage environment. The end closer to the user is designated as "proximal end", and the end farther from the user is designated as "distal end".

[0027] To facilitate understanding of the dilator, ureteral sheath, and endoscope assembly provided in the embodiments of this application, the relevant technologies will first be introduced in conjunction with the application scenarios below.

[0028] Even when dilators are used to open the walls of the urinary tract for insertion, there are still cases where insertion is not smooth enough or the resistance is too great.

[0029] Through research, the inventors discovered that the aforementioned problems were mainly caused by excessive sliding friction between the dilator and the cavity wall. Specifically, during the insertion of the relevant ureteral sheath, the dilator is usually pushed along the extension direction of the urinary system cavity. This causes the dilator to be subjected to greater sliding friction as it expands the cavity wall, increasing the difficulty of insertion. Especially when entering a narrower cavity (such as the ureter), the frictional resistance increases further, making it even more difficult to insert the ureteral sheath.

[0030] In addition, the aforementioned insertion obstruction can increase the risk of ureteral sheath scratching the ureteral cavity wall, which can easily lead to a stress response in the patient.

[0031] In view of this, embodiments of this application provide a dilator for a ureteral sheath.

[0032] Please refer to Figures 1 to 7. The dilator 100 disclosed in this application includes a dilator tube 110 and a clamp 120, wherein: the clamp 120 includes a base 121 and at least two clamping arms 122 distributed circumferentially along the base 121, and the clamp 120 can be connected to the proximal end of the sheath tube 200 of the ureteral sheath through the clamping arms 122; the base 121 has a mounting hole 121a, the proximal end of the dilator tube 110 passes through the mounting hole 121a, and the proximal end of the dilator tube 110 is engaged and positioned with the base 121 in both the axial and circumferential directions of the dilator 100.

[0033] It should be understood that the dilator 110 is the main component of the dilator 100, which can be inserted from the proximal end of the sheath 200 and extend to the distal end of the sheath 200. This provides a dilation effect outside the distal end of the sheath 200, that is, it expands the cavity wall within the human body cavity to facilitate the overall insertion of the ureteral sheath. The clip 120 is the connection structure between the dilator 110 and the sheath 200.

[0034] The clip 120 is fitted around the expansion tube 110 through the mounting hole 121a on the base 121, so that its circumferential clamping arms 122 can be clamped on the proximal end of the sheath 200, which is also fitted around the periphery of the expansion tube 110. Regarding the arrangement of the clamping arms 122, exemplarily, the clamping arms 122 include at least two arranged opposite each other on the circumferential direction of the base 121, so that the surgeon can press the two clamping arms 122 with their hands facing each other to open the free ends of the bottom of the clamping arms 122, thereby facilitating clamping on the proximal end of the sheath 200, as shown in Figures 1 and 5, specifically clamping on the connecting seat 220 at the proximal end of the sheath 200.

[0035] As described in the embodiments of this application, along the axial direction of the dilator 100, the proximal end of the dilator tube 110 is engaged with the base 121 for positioning, thus achieving relative fixation of the two in that direction, meaning that they will not move relative to each other. Under such conditions, during the insertion of the ureteral sheath, the dilator tube 110 can be fixed to the sheath tube 200 by the clamp 120. Even if both the dilator 100 and the sheath tube 200 are subject to resistance generated with the lumen wall, they will not move relative to each other, allowing the sheath tube 200 to be inserted along with the dilator 100 until it reaches the target site to establish a surgical channel.

[0036] To reduce resistance during ureteral sheath insertion, the ureteral sheath can be rotated. When the dilator 100 is rotated, rolling friction, rather than sliding friction, is generated between its distal end and the ureteral wall. The former has a smaller coefficient of friction, thereby reducing resistance and alleviating the obstruction of the ureteral sheath, thus facilitating the insertion operation. However, although the dilator 110 and the clamp are coaxially fitted in related technologies, they can rotate relative to each other. Because the proximal end of the dilator 100 is either hidden inside the base 121 of the clamp 120 or the portion extending out of the base 121 of the clamp 120 is extremely small, the operator can only achieve the rotation of the entire dilator 100 by simultaneously holding the proximal end of the dilator 110 and the clamp 120. This operation is extremely inconvenient and still does not improve the smoothness of insertion.

[0037] In this embodiment, the proximal end of the dilator tube 110 is also engaged with the base 121 along the circumference of the dilator 100. With this arrangement, the dilator tube 110 and the base 121 are relatively fixed along the circumference of the dilator 100, meaning they do not rotate relative to each other. During the insertion of the ureteral sheath, the entire dilator 100 can be rotated by rotating either the clamp 120 or the dilator tube 110. This allows the distal end of the dilator 100 (i.e., the distal end of the dilator tube 110) to rotate. By utilizing its relative movement with the cavity wall, the frictional resistance is changed from sliding friction to rolling friction, thereby alleviating insertion obstruction and improving the smoothness of the ureteral sheath insertion.

[0038] Rotary clip 120 is usually more convenient because it is larger and easier for the operator to hold.

[0039] Note that because the expansion tube 110 and the clip 120 are positioned and engaged along the circumference of the expander 100, even if the proximal end of the expansion tube 110 is hidden inside the base 121 of the clip 120, the entire expander 100 can still be rotated by rotating the clip 120.

[0040] There are multiple ways to simultaneously position and engage the expansion tube 110 and the base 121 of the clamp 120 in both the axial and circumferential directions of the expander 100, such as through a concave-convex structure to achieve positioning and engagement, but the embodiments of this application do not impose specific limitations.

[0041] For example, the base 121 includes a positioning portion disposed on the wall of the mounting hole 121a, at least a portion of which extends in a direction intersecting the axial direction of the mounting hole 121a, so as to simultaneously achieve axial and circumferential locking positioning of the proximal end of the expansion tube 110. The positioning portion can be a positioning rib or a positioning groove. With this arrangement, the base 121 achieves positioning engagement with the proximal end of the expansion tube 110 through the positioning portion. This positioning effect provides both axial restriction and circumferential limiting of the expander 100, thus achieving positioning engagement in two directions through the same positioning structure, thereby simplifying the structure.

[0042] For example, as shown in Figures 2 and 6, the base 121 includes a first positioning rib 121b and a second positioning rib 121c provided on the wall of the mounting hole 121a. The first positioning rib 121b extends axially along the mounting hole 121a to achieve circumferential locking positioning of the proximal end of the expansion tube 110, and the second positioning rib 121c extends circumferentially along the mounting hole 121a to achieve axial locking positioning of the proximal end of the expansion tube 110.

[0043] In this example, the positioning and engagement effect is achieved by the first positioning rib 121b and the second positioning rib 121c respectively. Specifically, as shown in Figures 2 and 3, the expansion tube 110 includes an adapter 112 with its proximal end. The adapter 112 has a first positioning groove 112a that engages with the first positioning rib 121b and a second positioning groove that engages with the second positioning rib 121c.

[0044] Furthermore, as shown in Figures 2 and 6, the first positioning rib 121b is connected to the second positioning rib 121c. This increases the overall strength of the first positioning rib 121b and the second positioning rib 121c, reducing the risk of damage to the clamp 120 during use.

[0045] In another further embodiment, as shown in FIG7, the second positioning rib 121c is provided at the far end of the mounting hole 121a, and the far end surface of the second positioning rib 121c is coplanar with the far end surface of the base 121.

[0046] It should be understood that with this layout, the part of the second positioning rib 121c facing the distal end is less difficult to deform because there is no hole wall of the base 121 on its distal end, and the deformation resistance is small. Therefore, this can facilitate the mutual insertion of the base 121 of the clip 120 and the proximal end of the expander 100, thereby improving the assembly efficiency. For details, please refer to Figure 2. The dashed arrow in Figure 2 shows the assembly direction of the two.

[0047] In addition, it is worth noting that the part of the second positioning rib 121c facing the proximal end is more difficult to deform because there is a hole wall of the base 121 on its proximal end, and the deformation resistance is greater. Therefore, in this way, during the insertion of the expander 100, the second positioning rib 121c can reliably and stably prevent the expansion tube 110 from separating from the clamp 120.

[0048] In some embodiments of this application, as shown in Figures 2 and 3, the expansion tube 110 includes a first tube body 111 and an adapter 112. The adapter 112 is fixedly installed at the distal end of the first tube body 111, and the expansion tube 110 is connected to the base 121 through the adapter 112. It should be understood that the first tube body 111 is the main body of the expansion tube 110. To facilitate insertion into the human body cavity, the radial dimension of the first tube body 111 is relatively small, and it is not convenient to process a positioning structure that mates with the clip 120 on it, thus reducing the probability of damage. Correspondingly, the size of the adapter 112 can be set to be larger to facilitate the processing of the positioning structure, thereby conveniently and reliably realizing the assembly of the expansion tube 110 and the clip 120.

[0049] To facilitate the assembly of the adapter 112 with the base 121 of the clip 120, the edge of the plug end of the adapter 112 may be provided with a guide structure, such as a guide bevel.

[0050] Please refer to Figures 1-7. An embodiment of this application provides a ureteral sheath, which includes a sheath tube 200 and a dilator 100 mentioned in any of the aforementioned schemes. This gives the ureteral sheath the beneficial effects of the aforementioned dilator 100, which will not be described in detail here. The dilator tube 110 can be inserted into the sheath tube 200, and the clamp 120 can be connected to the proximal end of the sheath tube 200 via the clamping arm 122.

[0051] The embodiments of this application do not specifically limit the specific connection method between the clamping arm 122 and the proximal end of the sheath 200.

[0052] Exemplarily, the clamping arm 122 bends distally to form a hook, which engages with the step on the connecting seat 220 at the proximal end of the sheath 200. Exemplarily, as shown in Figures 3-5, the clamping arm 122 bends distally and is inclined toward the central axis of the clamp 120. When the clamp 120 engages with the connecting seat 220 at the proximal end of the sheath 200, the inclined clamping arm 122 can extend below the edge of the side wall of the connecting seat 220 to engage axially.

[0053] Of course, the snap-fit ​​connector in this embodiment can be directly connected to the tube body of the sheath 200, such as the proximal end of the second tube body 210 described later.

[0054] In some embodiments of this application, as shown in Figures 3-6, the sheath 200 includes a second tube body 210 and a connecting seat 220 fixedly installed at the proximal end of the second tube body 210. The clamp 120 can be connected to the connecting seat 220 via a clamping arm 122. One of the outer peripheral wall of the connecting seat 220 and the clamping arm 122 is provided with a positioning protrusion 221, and the other with a positioning recess 122a. The positioning protrusion 221 can engage with the positioning recess 122a, thereby positioning the clamp 120 and the connecting seat 220 in a circumferential manner. In Figure 5, the clamp 120 can rotate relative to the sheath 200, realizing the rotation of the expander 100 relative to the sheath 200. In Figure 6, the clamp 120 and the connecting seat 220 are positioned in a circumferential manner, and the expander 100 and the sheath 200 are fixed relative to each other in a circumferential manner.

[0055] It should be understood that in some wider cavities, it is not necessary to rotate the dilator 100 to reduce insertion resistance. In this case, the clip 120 can be rotated to engage with the connector 220 circumferentially, thus fixing the dilator 100 and the sheath 200 circumferentially. This makes the connection between the two more stable, prevents relative misalignment, facilitates the surgeon to apply force axially, avoids wasting force, and improves insertion efficiency. In addition, the positioning protrusion 221 can also position the recess 122a to achieve axial locking, thereby strengthening the axial anti-dislodgement capability between the dilator 100 and the sheath 200.

[0056] In some embodiments of this application, as shown in Figures 3, 4 and 6, a positioning protrusion 221 is provided on the connecting seat 220, and a positioning recess 122a is provided on the clamping arm 122. This allows the clamping arm 122 to be opened at a larger angle so as to clamp more tightly and improve the axial anti-dislodgement capability between the expander 100 and the sheath 200.

[0057] Furthermore, as shown in Figures 2, 3 and 5, the clamping arm 122 is provided with a guide groove 122b, which extends circumferentially along the clamp 120 and corresponds to the positioning recess 122a, so that the positioning protrusion 221 slides into the positioning recess 122a through the guide groove 122b.

[0058] It should be understood that the guide groove 122b is actually a hollowed-out structure, and a channel is formed on the side wall of its positioning groove for the positioning protrusion 221 to slide into, thereby avoiding the obstruction of the side wall of the positioning recess 122a by the positioning protrusion 221 during the process of engaging with the positioning recess 122a. It is worth mentioning that in embodiments without the guide groove 122b, the entire clamp 120 needs to be pressed to make the clamping arm 122 expand radially outward, so that the positioning protrusion 221 can be smoothly engaged with the positioning recess 122a. In addition, when the positioning protrusion 221 is engaged with the positioning recess 122a by pressing the clamp 120, the clamping arm 122 is expanded radially outward, which may also pose a risk of the expander 100 disengaging from the sheath 200.

[0059] In this example, when it is necessary to position the expander 100 circumferentially relative to the sheath 200, the relative rotation of the clamp 120 and the connecting seat 220 can be achieved by rotating either the expander 100 or the sheath 200 (usually the expander 100). There is no need to press the clamp 120. That is, provided that the expander 100 and the sheath 200 are axially engaged without disengaging, the positioning protrusion 221 can slide unobstructed into the positioning recess 122a along the guide groove 122b. It can be seen that during this process, because the clamp 120 is not pressed, the axial relative position of the clamping arm 122 relative to the connecting seat 220 remains unchanged. Therefore, there is no need to observe the alignment of the positioning protrusion 221 and the positioning recess 122a, enabling blind insertion. Furthermore, the engagement can be confirmed by the sound and tactile feedback of the positioning protrusion 221 sliding into the positioning recess 122a.

[0060] Further, as shown in Figure 2, the bottom surface of the guide groove 122b is a first guide surface 122c, which is used to guide the positioning protrusion 221 to slide into the positioning recess 122a. The first guide surface 122c can be an inclined surface or an arc surface.

[0061] It should be understood that the first guide surface 122c can ensure that the guide groove 122b achieves the guiding effect on the positioning protrusion 221. In addition, the first guide surface 122c can increase the height of the side wall of the positioning recess 122a near the guide groove 122b, so that the positioning protrusion 221 is more reliably engaged after being inserted into the positioning recess 122a, reducing the risk of accidental separation.

[0062] In some embodiments of this application, as shown in Figures 3, 4 and 7, the sheath 200 includes a second tube body 210 and a connecting seat 220 fixedly installed at the proximal end of the second tube body 210. The clip 120 can be connected to the connecting seat 220 via a clamping arm 122. The inner wall of the connecting seat 220 is provided with a second guide surface 222, which is used to guide the expander 100 to slide into the second tube body 210. The base 121 has an abutment surface 121d located at its proximal edge. When the clip 120 is connected to the connecting seat 220, the base 121 abuts against the second guide surface 222 via the abutment surface 121d.

[0063] It should be understood that when the expander is connected to the connector 220 of the sheath 200 via the clip 120, the connector 220 is held by the clip 120 to achieve axial positioning. Typically, the connector 220 is held between the clamping arm 122 and the base 121. In this example, the base 121 of the clip 120 has an abutment surface 121d, which increases the contact area between the base 121 and the connector 220, avoids stress concentration, and reduces the risk of damage to the clip 120 and the connector 220. Simultaneously, the abutment surface 121d enhances the stress stability between the base 121 and the connector 220, and between the expander and the sheath 200, preventing misalignment or disengagement between the mating components, especially during the operator's axial advancement of the ureteral sheath.

[0064] In some embodiments of this application, as shown in FIG7, when the clip 120 is connected to the connecting seat 220, the portion of the clamping arm 122 clamping the outer peripheral wall of the connecting seat 220 along the radial direction of the clip 120 corresponds to the abutment surface 121d. The dashed line l in FIG7 indicates a radial direction of the clip 120.

[0065] It should be understood that the connecting seat 220 is clamped in the middle by the clamping arm 122 and the base 121, and the force application points of the two are corresponding in the radial direction of the clamp 120, which can improve the clamping effect of the clamp 120 on the connecting seat 220 and strengthen the anti-disengagement ability.

[0066] Embodiments of this application provide an endoscope assembly, including an endoscope and a ureteral sheath as mentioned in any of the foregoing solutions, thus enabling the endoscope assembly to possess the beneficial effects of the aforementioned ureteral sheath, which will not be elaborated further. The insertion portion of the endoscope can be inserted into the sheath 200.

[0067] The endoscopes referred to in this application embodiment may be bronchoscopes, pyeloscopes, esophagoscopes, gastroscopes, colonoscopes, otoscopes, rhinoscopes, oral endoscopes, laryngoscopes, colposcopes, laparoscopes, arthroscopes, etc. This application embodiment does not specifically limit the types of endoscopes.

[0068] The above embodiments of this application focus on describing the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be described in detail here.

[0069] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A dilator for a ureteral sheath, characterized in that, The expander includes an expansion tube and a clip, wherein: The clip includes a base and at least two clamping arms distributed circumferentially along the base, and the clip can be connected to the proximal end of the ureteral sheath via the clamping arms; The base has a mounting hole, the proximal end of the expansion tube passes through the mounting hole, and the proximal end of the expansion tube is engaged with the base in both the axial and circumferential directions of the expander.

2. The expander according to claim 1, characterized in that, The base includes a first positioning rib and a second positioning rib disposed on the wall of the mounting hole. The first positioning rib extends axially along the mounting hole to achieve circumferential locking and positioning of the proximal end of the expansion tube. The second positioning rib extends circumferentially along the mounting hole to achieve axial locking and positioning of the proximal end of the expansion tube. Wherein: the first positioning rib is connected to the second positioning rib; and / or, the second positioning rib is located at the far end of the mounting hole, and the far end face of the second positioning rib is coplanar with the far end face of the base.

3. The expander according to claim 1, characterized in that, The base includes a positioning portion disposed on the wall of the mounting hole, and at least a portion of the positioning portion extends in a direction intersecting the axial direction of the mounting hole, so as to simultaneously achieve axial and circumferential snap-fit ​​positioning of the proximal end of the expansion tube. And / or, the expansion tube includes a first tube body and an adapter, the adapter being fixedly installed at the distal end of the first tube body, and the expansion tube being connected to the base via the adapter.

4. A ureteral sheath, characterized in that, The device includes a sheath and an expander according to any one of claims 1 to 3, wherein the expander can be inserted into the sheath, and the clamp can be connected to the proximal end of the sheath via the clamping arm.

5. The ureteral sheath according to claim 4, characterized in that, The sheath includes a second tube body and a connecting seat fixedly installed at the proximal end of the second tube body. The clamp can be connected to the connecting seat through the clamping arm. In the outer peripheral wall of the connecting seat and the clamping arm, one is provided with a positioning protrusion and the other is provided with a positioning recess. The positioning protrusion can be engaged with the positioning recess so that the clamp and the connecting seat are positioned and engaged in a circumferential manner.

6. The ureteral sheath according to claim 5, characterized in that, The positioning protrusion is provided on the connecting seat, and the positioning recess is provided on the clamping arm; the clamping arm is provided with a guide groove, the guide groove extends along the circumference of the clamp, and the guide groove corresponds to the positioning recess, so that the positioning protrusion slides into the positioning recess through the guide groove.

7. The ureteral sheath according to claim 6, characterized in that, The bottom surface of the guide groove is a first guide surface, which is used to guide the positioning protrusion into the positioning recess.

8. The ureteral sheath according to claim 4, characterized in that, The sheath includes a second tube body and a connecting seat fixedly installed at the proximal end of the second tube body. The clamp can be connected to the connecting seat via the clamping arm. The inner wall of the connecting seat is provided with a second guide surface, which is used to guide the expander to slide into the second tube body. The base has an abutment surface located at its proximal edge. When the clamp is connected to the connecting seat, the base abuts against the second guide surface through the abutment surface.

9. The ureteral sheath according to claim 8, characterized in that, When the clip is connected to the connector, the portion of the clamping arm that clamps the outer peripheral wall of the connector is arranged in a radial direction of the clip, corresponding to the abutment surface.

10. An endoscope assembly, characterized in that, Includes an endoscope and a ureteral sheath according to any one of claims 4 to 9, wherein the insertion portion of the endoscope can be inserted into the sheath.

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