A guide sheath

Abstract

The utility model relates to the field of medical devices, concretely is a kind of guide sheath for urological surgery. The guide sheath includes sheath tube and handle: sheath tube is suitable for inserting in human body;Handle is connected with the proximal end side of sheath tube, and both jointly define the working channel extending from proximal end towards distal end. Handle is equipped with negative pressure connector, pressure regulating groove and sliding cover, wherein negative pressure connector is communicated with working channel and is adapted to negative pressure source, and working channel and negative pressure connector cooperate to constitute the suction path of waste liquid discharge;Pressure regulating groove is communicated with working channel and is far from suction path, can avoid liquid splashing pollution;Sliding cover is slidably arranged at pressure regulating groove, can realize the opening, closing or size adjustment of pressure regulating groove, facilitate accurate regulation working channel negative pressure, improve operation aseptic safety and operational convenience.

Description

Technical Field

[0001] This utility model belongs to the field of medical device technology, specifically relating to a flexible guide sheath used in urological surgery. Background Technology

[0002] Flexible ureteral guiding sheaths are used in urological surgeries to establish a pathway for endoscopes and other instruments to enter the urinary tract. These sheaths can be used in conjunction with an irrigation pump to achieve negative pressure suction, drawing fluid from the renal pelvis into a collection device. During the procedure, current technology involves water entering the endoscope's working channel and exiting through the gap between the endoscope and the sheath, creating negative pressure suction to promptly remove laser-dislodged stone fragments.

[0003] Furthermore, existing flexible ureteral guiding sheaths all have air inlets in the side channel, with air intake adjusted via a sealing cap, sealing slider, or finger pressure. The sealing cap type can only be fully opened or fully closed, while the sealing slider or finger-press type requires the doctor to touch the slider or directly cover part or all of the air inlet for operation. This can potentially cause bodily fluids to splash onto the doctor's hands or body, causing contamination. In actual use, sealing sliders and finger-press types can experience leaks during sealing, resulting in an unsatisfactory seal and an unstable negative pressure environment, which reduces the efficiency of stone removal from the renal pelvis. Utility Model Content

[0004] This utility model provides a guide sheath, characterized in that the guide sheath comprises:

[0005] A sheath, suitable for insertion into the human body;

[0006] A handle is connected to the proximal end of a sheath. The handle and the sheath together define a working channel extending from the proximal end to the distal end. The handle is provided with a negative pressure connector, a pressure regulating groove, and a sliding cover. The negative pressure connector communicates with the working channel and is adapted to be connected to a negative pressure source. The working channel and the negative pressure connector cooperate to form a suction path for waste liquid discharge. The pressure regulating groove communicates with the working channel and is located away from the suction path. The sliding cover is slidably disposed at the pressure regulating groove to open, close, or adjust the size of the pressure regulating groove.

[0007] In some embodiments, the handle includes a horizontally arranged slide and a sliding cover slidably disposed on the slide; the slide has a strip-shaped pressure regulating groove; the sliding cover, through its sliding engagement with the slide, can move along the length of the slide to fully open, fully close, or partially open the pressure regulating groove.

[0008] In some embodiments, a sealing element is provided between the pressure regulating groove and the sliding cover, and the sliding cover forms a sealed fit with the pressure regulating groove through the sealing element.

[0009] In some embodiments, the handle further includes a sliding guide assembly connected between the sliding cover and the handle, the sliding guide assembly comprising:

[0010] A slide rail is provided at the handle, and the slide rail extends along the moving direction of the sliding cover;

[0011] A sliding member is provided on the sliding cover, and the sliding member is slidably engaged with the slide rail.

[0012] In some embodiments, the handle is symmetrically provided with strip-shaped grooves, and the sliding cover is provided with a retaining strip that slides in conjunction with the strip-shaped grooves.

[0013] In some embodiments, a sealing ring is provided around the inner periphery of the pressure regulating groove; the inner wall of the sliding cover presses tightly against the sealing ring to achieve a seal.

[0014] In some embodiments, the sheath comprises, from proximal to distal, a large-diameter section, a transition section, and a small-diameter section, wherein the large-diameter section defines a large channel, the small-diameter section defines a small channel, the diameter of the large channel is larger than the diameter of the small channel, the large-diameter section is a rigid tube section, and at least a portion of the distal section of the small-diameter section is a flexible section.

[0015] In some embodiments, the large-diameter section and the small-diameter section are axially eccentrically arranged, and a portion of the pipe wall of the small-diameter section is tangent to the inner surface of the pipe wall of the large-diameter section.

[0016] In some embodiments, the handle includes:

[0017] The tube seat connects to the proximal end of the sheath.

[0018] A connecting cap, which connects to the proximal end of the tube seat;

[0019] A seal that connects to a connecting cap, the seal being interference-fitted within a tube seat, the seal defining an inlet for external instruments to enter.

[0020] A connecting part, which is provided on the connecting cap, is used for detachable connection with the expander.

[0021] In some embodiments, the connecting portion includes:

[0022] At least two connecting clips are used for the snap-fit ​​engagement of the expander's elastic arm;

[0023] At least two limiting protrusions are distributed along the circumferential direction of the connecting cap to prevent circumferential displacement of the expander. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the handle of this utility model;

[0025] Figure 2 for Figure 1 Cross-sectional view along the AA direction;

[0026] Figure 3 This is a schematic diagram of the pressure regulating component of this utility model in a partially intake state;

[0027] Figure 4 This is a schematic diagram of the voltage regulating component of this utility model in the fully open state;

[0028] Figure 5 This is a structural schematic diagram of the handle (with the sliding cover removed) of this utility model.

[0029] Figure 6 This is a cross-sectional structural diagram of the handle of this utility model;

[0030] Figure 7 This is a schematic cross-sectional view of the ureteral guiding sheath of this utility model;

[0031] Figure 8 for Figure 7 A magnified view of a portion of the image;

[0032] Figure 9 This is a schematic diagram of the structure of the connecting part of this utility model;

[0033] Figure 10 for Figure 9 Enlarged view of a part

[0034] Figure 11 This is a schematic diagram of the sheath structure in an embodiment of the present invention;

[0035] Figure 12 This is a schematic diagram of the insertion of the ureteral guiding sheath into the urinary tract in an embodiment of this utility model;

[0036] Figure 13 A schematic diagram showing the working state of the flexible ureteroscope after insertion into the sheath of this utility model;

[0037] Figure 14 This is a schematic diagram of the cooperation structure between the sheath and the flexible ureteroscope in another embodiment of the present invention;

[0038] in:

[0039] 1-Sheath,

[0040] 2-handle,

[0041] A-urethral tube,

[0042] A1-Pubic flexion,

[0043] A2 - Subpubic curve,

[0044] B-bladder,

[0045] C-ureter,

[0046] D-renal pelvis,

[0047] 11-Small diameter section,

[0048] 12-Transition section,

[0049] 13-Large diameter section,

[0050] 111-Flexible segment,

[0051] 112-Hard segment;

[0052] 100-stones,

[0053] 3-Ureteroscopy,

[0054] 21-Pressure regulating tank,

[0055] 22- Sliding cover,

[0056] 220-sliding platform;

[0057] 23-Sealing ring,

[0058] 20-Negative pressure connector,

[0059] 24-Slide groove,

[0060] 25-card strip;

[0061] 261-tube seat,

[0062] 260-Connecting Cap,

[0063] 262-Seals,

[0064] 263-Connecting buckle,

[0065] 267-Limiting Protrusion

[0066] 264-Limiting groove,

[0067] 265-protrusion,

[0068] 266-Limit Block;

[0069] 51-Expander connection platform,

[0070] 52-Elastic Arm

[0071] 200-Guide ramp. Detailed Implementation

[0072] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0073] In the description of this utility model, it should be understood that the terms "length", "upper", "lower", "near", "far", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "longitudinal", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0074] The ureteral negative pressure guiding sheath system is used to establish a passage through the urethra and bladder to the ureter and renal pelvis. The system mainly consists of core components such as a ureteral guiding sheath, a dilator, and a flexible ureteroscope. During the procedure, the surgeon first inserts a guidewire into the target ureter; then, the dilator is inserted into the ureteral guiding sheath, and together they are advanced along the guidewire to gradually dilate the ureteral opening. Once the distal end of the sheath reaches the target renal pelvis, the dilator and guidewire are withdrawn. At this point, the working channel of the ureteral guiding sheath provides a pathway for the repeated insertion and removal of surgical instruments such as the flexible ureteroscope, laser fiber, and stone retrieval basket.

[0075] Existing ureteral guiding sheaths typically include a slender sheath, a handle connected to the proximal end of the sheath, and a pressure regulating assembly. The handle and sheath together define a working channel extending from the proximal end to the distal end. The handle has a negative pressure connector communicating with the working channel, which can be used to connect a negative pressure device, thereby establishing a negative pressure environment within the working channel. During surgery, water is often introduced through the working channel of the endoscope, and water exits through the gap between the endoscope and the sheath, creating negative pressure suction to remove laser-induced lithotripsy.

[0076] Please see Figure 1 This utility model provides an improved negative pressure guiding sheath based on the existing technology, which includes a sheath tube 1, a handle 2 and a pressure regulating component.

[0077] Structure of the voltage regulating component:

[0078] Existing negative pressure connectors have pressure regulating ports, which can cause bodily fluids to splash onto the doctor's hands or body parts, causing contamination. Therefore, operators can adjust the negative pressure of the working channel by sliding a cover or by hand, easily leading to hand contamination.

[0079] Based on this existing technical issue, please refer to Figures 1-4 The pressure regulating component provided in this embodiment is mounted on the handle 2. Specifically, the pressure regulating component includes a pressure regulating groove 21 and a sliding cover 22. The negative pressure connector 20 is connected to the working channel and is adapted to be connected to a negative pressure source. The working channel and the negative pressure connector cooperate to form a suction path for waste liquid discharge. The pressure regulating groove 21 is connected to the working channel and is located away from the suction path. In this way, the liquid aspirated during surgery is extremely difficult to splash out from the pressure regulating groove 21, fundamentally avoiding contamination of the surgeon's hands and the surgical environment, and improving the aseptic safety of the surgery. The sliding cover 22 is slidably mounted on the pressure regulating groove to open, close, or adjust the size of the pressure regulating groove 21. The operator can easily adjust the negative pressure by sliding the sliding cover.

[0080] Please refer to some embodiments of this utility model. Figure 5 The handle 2 includes a horizontally arranged slide 220 and a sliding cover 22 slidably disposed on the slide 220. During surgery, the doctor typically holds the handle with one hand, and the thumb or forefinger can naturally perform horizontal pushing and pulling movements to adjust the sliding cover. This design avoids operational inconvenience, accidental touches, or inaccuracies that may result from tilting or vertical movement, ensuring smooth, continuous, and precise pressure adjustment. The slide has a strip-shaped pressure regulating groove 21; the sliding cover 22, through its sliding engagement with the slide, can move along the length of the slide 220 to fully open, fully close, or partially open the pressure regulating groove. Specifically, the essence of the pressure regulating function is to adjust the negative pressure suction force within the working channel by changing the exposed area of ​​the air inlet, i.e., the pressure regulating groove. When the sliding cover fully exposes the pressure regulating groove, it means that the air inlet area reaches its maximum value. The arrangement of the slide 220 ensures that the adjustment range of the negative pressure suction force can continuously change from 100% (pressure regulating groove fully closed) to 0% (pressure regulating groove fully open).

[0081] In some specific embodiments of this utility model, the handle further includes a sliding guide assembly connected between the sliding cover and the handle. The sliding guide assembly includes a slide rail located at the handle and a sliding member located on the sliding cover. The slide rail extends along the length of the pressure regulating groove, and the sliding member slidably engages with the slide rail. The shape of the sliding member is adapted to the cross-section of the slide rail, allowing it to be nested or engaged on the slide rail and to slide freely along the extension direction of the slide rail. The engagement of the sliding member and the slide rail forms a sliding pair. This ensures that the sliding cover 22 can only move along a preset straight path, eliminating the possibility of deflection, tilting, or jamming, and ensuring smooth movement of the sliding cover. Furthermore, the slide rail has a stop that limits the travel of the sliding member. The stop provides a mechanical hard limit, effectively preventing accidents caused by excessive sliding, ensuring that the position of the sliding cover is consistent each time it moves to the fully open and fully closed states. In addition, it provides clear tactile feedback, such as a sudden increase in weight, allowing the user to know that the limit position has been reached without visual confirmation. For details, please refer to... Figure 5 and Figure 6 The handle is symmetrically provided with strip-shaped grooves 24, and the sliding cover 22 is provided with a retaining strip 25 that slides in conjunction with the strip-shaped grooves 24. During assembly, the retaining strip on the sliding cover 22 is aligned with the strip-shaped groove 24 on the handle 2, and pressed vertically or slid horizontally to embed the retaining strip into the groove. Thereafter, the sliding cover 22 is connected to the handle 2 through the engagement of the retaining strip and the groove. The retaining strip is restricted to movement within the strip-shaped groove, allowing the sliding cover 22 to slide along a straight path, avoiding the risk of tilting, shaking, or jamming during operation, and ensuring a smooth and stable sliding feel. Furthermore, the inner walls at both ends of the strip-shaped groove 24 naturally form mechanical limits for the sliding cover's movement. When the sliding cover 22 slides to the point where its retaining strip contacts the inner wall of either end of the groove, movement is physically stopped, defining the maximum opening stroke and fully closed position of the sliding cover 22, preventing component detachment or seal failure due to excessive movement. Optionally, please refer to... Figure 6 The handle 2 is provided with a long sliding groove 24, and the sliding cover 22 is provided with a zig-shaped buckle that slides in cooperation with the sliding groove 24.

[0082] In some embodiments of this utility model, a sealing element is provided in the pressure regulating groove 21, and the sliding cover 22 achieves a sealing fit by contacting the sealing element. For details, please refer to... Figure 2 The pressure regulating groove 21 has a circumferentially formed mounting groove on its inner edge, and the sealing ring 23 is embedded in the mounting groove. The inner sidewall of the sliding cover 22 is in close contact with the sealing ring 23, forming an airtight seal. The negative pressure attraction can be continuously adjusted by sliding the sliding cover 22: when the sliding cover 22 moves to the near end of the pressure regulating groove 21, its inner sidewall is completely airtightly connected with the sealing ring 23, at which time the pressure regulating groove 21 is completely closed, and the negative pressure attraction in the working channel reaches its maximum; when the sliding cover 22 slides to the far end of the pressure regulating groove 21, its contact area with the sealing ring 23 gradually decreases, the opening of the pressure regulating groove 21 gradually increases, external air is drawn in, and the negative pressure attraction in the working channel decreases accordingly; when the sliding cover 22 moves to the far end of the pressure regulating groove 21, its contact area with the sealing ring 23 is minimum, the opening of the pressure regulating groove 21 reaches its maximum, the amount of air drawn in is maximum, and the negative pressure attraction in the working channel drops to its minimum.

[0083] This design allows doctors to precisely and smoothly adjust the negative pressure suction with a single finger sliding motion, making operation intuitive and simple. Simultaneously, because the air inlet of the pressure regulating groove 21 is far from the main suction path and maintains a reliable seal, the risk of waste fluid splashing during surgery is effectively avoided, significantly improving the aseptic safety and convenience of the surgical procedure. The formula for the air inlet area is: width of the sheath pressure regulating groove 21 * moving distance. In practical applications, the maximum air inlet area is greater than or equal to the cross-sectional area of ​​the suction channel. When the air inlet area is at its maximum, because the resistance to air intake from the pressure regulating groove 21 is much less than the resistance to fluid intake from the renal pelvis, most of the suction force is used to intake outside air, thus significantly reducing or even almost stopping the suction of fluid from the renal pelvis D. Therefore, by sliding the upper cover 22, the suction force of the suction cavity can be adjusted from 100% to near 0%, greatly increasing the convenience and precision of the surgeon during the operation.

[0084] Structure of handle 2:

[0085] Please see Figure 7 and Figure 8 The handle 2 includes a tube seat 261, a connecting cap 260, a sealing element 262, and a connecting part. The tube seat 261 is connected to the proximal end of the sheath; the connecting cap 260 is connected to the proximal end of the tube seat 261; the sealing element 262 is connected to the connecting cap 260, and the connecting cap 260 and the sealing element 262 are fixedly connected, ensuring that when the connecting cap 260 and the tube seat 261 are engaged, the sealing element 262 is interference-fitted within the tube seat 261, effectively preventing leakage of fluid from the joint between the tube seat 261 and the connecting cap 260 during surgery, avoiding contamination of the surgical environment and the operator, and improving the safety of the surgery. The sealing element 262 defines an entrance for external instruments. While allowing instruments such as ureteroscopes to pass freely, the entrance also covers the surface of the instruments, reducing air leakage when the instruments enter or exit, minimizing interference with the external negative pressure suction effect, and making the surgical operation smoother. The connecting part is located on the connecting cap 260, which is used for detachable connection with the expander. The expander can be quickly and securely installed and disassembled with one click through mechanical structures such as buckles, which simplifies the surgical preparation and instrument replacement steps and significantly improves surgical efficiency.

[0086] Optionally, the handle 2 is also equipped with a fixed finger ring for easy gripping by doctors.

[0087] In some embodiments of this invention, the connecting portion includes at least one connecting snap 263 that engages with the proximal end of the expander and at least one limiting protrusion 267 for preventing circumferential movement of the expander. The connecting snap and limiting protrusion enable one-click quick connection and disconnection between the expander and the guide sheath. The connecting snap provides reliable axial locking, ensuring the expander will not accidentally dislodge during advancement, thus guaranteeing the stability of the surgical procedure. The circumferentially distributed limiting protrusions prevent rotation of the expander relative to the guide sheath, eliminating potential circumferential movement after connection. Optionally, please refer to... Figure 9 The connecting part includes two connecting clips 263 and several limiting protrusions 267 for engaging with the elastic arm 52 of the expander. The limiting protrusions 267 are distributed circumferentially along the connecting cap 260 to restrict the rotation of the expander. When the expander is inserted, its elastic arm 52 is compressed and deformed, causing the expander connecting platform 51 to engage with the connecting clips 263, achieving axial fixation. (See also...) Figure 10 The limiting protrusion 267 forms a guide ramp 200 near the connecting buckle. This guide ramp is inclined away from the limiting buckle relative to it. Thus, when the expander is subjected to a large torque, the connecting platform 51 can slide along the guide ramp 200 and compress the elastic arm 52 inward, thereby disengaging from the buckle for easy removal. Alternatively, the elastic arm 52 can be directly pressed inward to achieve quick disassembly of the expander. The guide ramp provides a safe slip mechanism when subjected to excessive torque, preventing component damage, and also provides a guiding slope for pressing the elastic arm during normal disassembly, making the disassembly action easier and faster.

[0088] Optionally, the sealing element 262 and the connecting cap 260 are integrally formed or separately connected. In some examples, the sealing element 262 is a silicone cap, and the connecting cap 260 and the tube body are both rigid components.

[0089] Optionally, the tube seat 261 is provided with a boss 265 and a limiting groove 264 near its end, and the connecting cap 260 is provided with a limiting block 266, which can be inserted into the limiting groove 264 to form a snap-fit ​​connection, thereby achieving axial and circumferential fixation, while allowing force to be applied to pull it out when needed.

[0090] Sheath 1 structure:

[0091] Please see Figure 11 and Figure 12The sheath 1, from proximal to distal, comprises a large-diameter section 13, a transition section 12, and a small-diameter section 11. The large-diameter section 13 defines a large channel, and the small-diameter section 11 defines a small channel. The large-diameter section 13 is a rigid tube made of a rigid material, and its diameter and rigidity are configured to expand and straighten the physiological curvature of the urethra (A1-prepubic curve, A2-subpubic curve) when placed in the urethral tube A. Thus, the flared section of the sheath 1, i.e., the large-diameter section 13, has the highest rigidity. The large-diameter section 13 is supported within the urethral tube A, and the small-diameter section 11 is supported within the ureter C. The transition section 12, between the large-diameter section 13 and the small-diameter section 11, enters the bladder B without contacting the ureteral orifice. The high rigidity allows the large-diameter segment 13 to remain undeformed within the two physiological bends of the male urethra, straightening these bends. This reduces the flow of stone fragments 100 from the two large bends required for drainage, preventing them from getting stuck at the bends. The larger internal space and straighter lumen of the sheath also facilitate frequent insertion and withdrawal of the endoscope by the physician. At least a portion of the distal segment 11 of the small-diameter segment 11 is a flexible segment 111. This flexible segment 111 can passively or actively deflect with the bends of the ureteroscope, allowing the instrument to be aligned with the target location.

[0092] Handle 2 connects to the proximal end of the large-diameter section 13, and together with the sheath 1, defines a working channel extending from the proximal end to the distal end. Handle 2 is equipped with a negative pressure connector 20 that communicates with the working channel for connecting a negative pressure device to establish a negative pressure environment. A pressure regulating assembly is used to adjust the pressure in the working channel. (See also...) Figure 13 The larger inner diameter of the large-diameter section 13 expands the gap between the sheath 1 and the flexible ureteroscope 3, reducing the length of time the doctor needs to withdraw the scope. When the doctor withdraws to the dilated section, it is easier to expel the stone, effectively preventing the stone 100 from accumulating in the gap, accelerating the expulsion of stone fragments 100, and greatly improving the efficiency of the operation.

[0093] In some embodiments of this invention, the distal end of the sheath 1 is a flexible segment 111, and the hardness of the transition segment 12 is between that of the large-diameter segment 13 and the small-diameter segment 11. The large-diameter segment 13 has the highest hardness, the largest outer diameter, and the largest inner diameter among the three segments. The transition segment 12 is a transitional region where the inner and outer diameters of the hard segment 112 gradually increase to the size of the flared segment. In this embodiment, the sheath 1 is entirely a multi-layered tube structure, consisting of an inner tube, a metal layer, and an outer tube from the inside out. Exemplarily, the inner tube is mostly an externally etched PTFE tube, which ensures effective connection between the inner and outer tubes and a smooth inner wall for easy instrument passage. The metal layer uses stainless steel flat wire to increase the overall support performance of the tube wall. The outer tube is mainly made of Pebax and TPU. The flexible segment 111 has a lower material hardness and can be bent according to the bending direction of the endoscope, while the hard tube segment has a higher hardness, facilitating the pushing of the sheath 1 in the urethra and ureter C.

[0094] It is understood that the small-diameter section 11, the transition section 12, and the large-diameter section 13 can be integrally formed or connected separately. Please refer to the previous document for further details. Figure 11 The small-diameter segment 11 includes a distal flexible segment 111 and a proximal hard segment 112. Example 1: The large-diameter segment 13 uses a metal tube, which can be made of 304 stainless steel. The small-diameter segment 11 and transition segment 12 of the sheath 1 are multi-layered tubes. The spring of the inner layer of the tube winds along the hard segment 112 to the transition segment 12, and the outer layer of the hard segment 112 also fits onto the transition segment 12, increasing the connection between the hard segment 112 and the metal tube, ensuring a firm connection that will not fall off. This metal tube, as the large-diameter segment 13, can completely straighten the male physiological curvature, making it easier to remove stones and improving efficiency. Example 2: The large-diameter segment 13 uses a rigid plastic tube, made of high-hardness PA or Pebax. After the small-diameter segment 11 and transition segment 12 of the sheath 1 are formed, a special flared mandrel is inserted, and then the rigid plastic tube is fitted. The two are then heat-fused at the transition segment 12 of the flared mandrel to form the final shape. Example 3: The sheath 1 has a three-layer structure, consisting of an inner tube, a metal layer, and an outer tube from the inside out. The difference lies in the inner and outer diameters of each layer, which increase along the transition section 12. The outer tubes are made of the same material, and their hardness can be adjusted accordingly. Alternatively, the outer tubes may be made of different materials, resulting in different hardnesses. This one-piece molded sheath 1 integrates the advantages of a split structure. Compared to a split structure using rigid plastic tubes, it has higher hardness and support, while also being lighter in weight. Furthermore, the inner and outer surfaces at the connection of the transition section 12 are smoother and more stable and reliable.

[0095] In another embodiment, please refer to Figure 14The large-diameter segment 13 and the small-diameter segment 11 are arranged axially eccentrically, with the axial projection of the small-diameter segment 11 onto the large-diameter segment 13 located within the cross-sectional contour of the large-diameter segment 13. This eccentric design causes the endoscope (such as the ureteroscope 3) to deflect to one side after entering the large-diameter segment 13, forming a larger stone-discharge channel on the other side. This effectively prevents the accumulation of stones 100 in the gap and prevents larger stones from getting stuck between the endoscope and the inner wall of the sheath, thus avoiding the need for frequent insertion and withdrawal of the endoscope by the doctor and further improving the stone fragmentation and removal efficiency. More specifically, the outer surface of part of the wall of the small-diameter segment 11 is tangent to the inner surface of the wall of the large-diameter segment 13, maximizing the stone-discharge channel.

[0096] In the description of this specification, the references to terms such as "embodiment," "specific embodiment," and "example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0097] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A guide sheath, comprising: The guiding sheath includes: A sheath, suitable for insertion into the human body; A handle is connected to the proximal end of a sheath. The handle and the sheath together define a working channel extending from the proximal end to the distal end. The handle is provided with a negative pressure connector, a pressure regulating groove, and a sliding cover. The negative pressure connector communicates with the working channel and is adapted to be connected to a negative pressure source. The working channel and the negative pressure connector cooperate to form a suction path for waste liquid discharge. The pressure regulating groove communicates with the working channel and is located away from the suction path. The sliding cover is slidably disposed at the pressure regulating groove to open, close, or adjust the size of the pressure regulating groove.

2. The introducer sheath of claim 1, wherein, The handle includes a horizontally arranged slide and a sliding cover slidably disposed on the slide; the slide has a strip-shaped pressure regulating groove; the sliding cover, through its sliding engagement with the slide, can move along the length of the slide to fully open, fully close, or partially open the pressure regulating groove.

3. The introducer sheath of claim 1, wherein, A sealing element is provided between the pressure regulating groove and the sliding cover, and the sliding cover forms a sealed fit with the pressure regulating groove through the sealing element.

4. The guiding sheath according to claim 1, characterized in that, The handle further includes a sliding guide assembly connected between the sliding cover and the handle, the sliding guide assembly comprising: A slide rail is provided at the handle, and the slide rail extends along the moving direction of the sliding cover; A sliding member is provided on the sliding cover, and the sliding member is slidably engaged with the slide rail.

5. The guiding sheath according to claim 4, characterized in that, The handle is symmetrically provided with strip-shaped grooves, and the sliding cover is provided with a retaining strip that slides in conjunction with the strip-shaped grooves.

6. The guiding sheath according to claim 4, characterized in that, A sealing ring is provided around the inner circumference of the pressure regulating groove; the inner wall of the sliding cover presses tightly against the sealing ring to achieve a seal.

7. The guiding sheath according to claim 1, characterized in that, The sheath, from proximal end to distal end, comprises a large-diameter section, a transition section, and a small-diameter section. The large-diameter section defines a large channel, and the small-diameter section defines a small channel. The diameter of the large channel is larger than the diameter of the small channel. The large-diameter section is a rigid tube section, and at least a portion of the distal section of the small-diameter section is a flexible section.

8. The guiding sheath according to claim 7, characterized in that, The large-diameter section and the small-diameter section are axially eccentrically arranged, and part of the pipe wall of the small-diameter section is tangent to the inner surface of the pipe wall of the large-diameter section.

9. The guiding sheath according to claim 1, characterized in that, The handle includes: The tube seat connects to the proximal end of the sheath. A connecting cap, which connects to the proximal end of the tube seat; A seal that connects to a connecting cap, the seal being interference-fitted within a tube seat, the seal defining an inlet for external instruments to enter. A connecting part, which is provided on the connecting cap, is used for detachable connection with the expander.

10. The guiding sheath according to claim 9, characterized in that, The connecting part includes: At least two connecting clips are used for the snap-fit ​​engagement of the expander's elastic arm; At least two limiting protrusions are distributed along the circumferential direction of the connecting cap to prevent circumferential displacement of the expander.

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