A sheath and endoscope assembly
By controlling the axial sliding of the guide tube on the sealing cap, the problems of difficult insertion of the existing sheath tube and inconvenient negative pressure control are solved, realizing convenient use of the sheath tube and improving the comfort of the endoscope assembly.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUNAN VATHIN MEDICAL INSTR CO LTD
- Filing Date
- 2026-04-23
- Publication Date
- 2026-06-26
Smart Images
Figure CN122074878B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of endoscopy technology, and more particularly to a sheath and endoscopy assembly. Background Technology
[0002] The sheath is a disposable medical consumable that is fitted over the endoscope. It is mostly made of medical polymer materials (such as polyurethane and polyethylene) and has core functions such as protection, operation assistance, and field of vision protection. It is an indispensable accessory in endoscopic examinations / minimally invasive surgeries such as gastroscopy, colonoscopy, bronchoscopy, and ureteroscopy.
[0003] In practical applications, the sheath can be used with an endoscope to remove samples from the body through negative pressure aspiration. To facilitate the integration of functions such as negative pressure control and sample buffering on the sheath seat of the sheath, a cavity structure is usually set on the sheath seat of the sheath. However, due to the limitations of the sheath itself, the existing design has the problem of inconvenience in inserting the insertion part of the sheath. Summary of the Invention
[0004] The purpose of this application is to provide a sheath and endoscope assembly to solve the aforementioned technical problems existing in the prior art.
[0005] This application is implemented as follows:
[0006] In a first aspect, this application provides a sheath comprising:
[0007] The sheath seat has a negative pressure interface, a tube body at the distal end of the sheath seat for inserting an endoscope, a sealing cap at the proximal end of the sheath seat, and the sealing cap and the sheath seat forming a cavity. The negative pressure interface communicates with the tube body through the cavity. The sealing cap has an adjustment channel communicating with the cavity in the middle. The distal end of the adjustment channel has a first sealing surface. The sheath seat has a second sealing surface on the inner wall near the tube body.
[0008] A guide tube is provided for inserting an endoscope into the endoscope. The distal end of the guide tube passes through the control channel and is positioned close to the tube body. An upper sealing ring and a lower sealing ring are provided on the guide tube. The guide tube and the control channel have an axial sliding stroke, which includes a first state and a second state. In the first state, the upper sealing ring and the first sealing surface are sealed together, and there is a first gap between the lower sealing ring and the second sealing surface. The lower sealing ring and the endoscope insertion part are sealed together. In the second state, the lower sealing ring and the second sealing surface are expanded together, and the expanded deformation of the lower sealing ring forms a second gap with the endoscope insertion part. There is a third gap between the upper sealing ring and the first sealing surface.
[0009] Secondly, this application provides an endoscope assembly, including an endoscope and the aforementioned sheath, wherein the insertion portion of the endoscope is sequentially disposed in a guide tube, a cavity, and a tube body.
[0010] The technical solution provided in this application can achieve the following beneficial effects:
[0011] This application utilizes a guide tube to directly guide the insertion part to the near port of the tube body, shortening the suspended distance of the insertion part from the lower sealing ring to the near port of the tube body. This reduces the difficulty of inserting the insertion part into the sheath tube body. At the same time, based on the axial sliding control of the guide tube on the sealing cover, when controlling the guide tube to switch between the first and second states, it not only reduces the resistance to rapid insertion / removal of the insertion part from the sheath tube, but also blocks the connection between the negative pressure interface and the tube body through the cooperation of the lower sealing ring and the second sealing surface. This eliminates the need for the existing switch structure on the negative pressure interface, simplifies the sheath tube structure, and achieves simultaneous control of negative pressure regulation and insertion part sealing control in one structure, effectively improving the ease of use of the sheath tube. Attached Figure Description
[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0013] Figure 1 This is a schematic diagram of the operation of the endoscope assembly disclosed in the embodiments of this application;
[0014] Figure 2 This is a structural diagram of the sheath disclosed in the embodiments of this application;
[0015] Figure 3 This is a schematic diagram of the internal structure of the sheath (first state) disclosed in an embodiment of this application;
[0016] Figure 4 This is a top view of the sheath (first state) disclosed in the embodiments of this application;
[0017] Figure 5 yes Figure 4 Sectional view along line AA;
[0018] Figure 6 yes Figure 5 A magnified view of a section at point B in the middle;
[0019] Figure 7 This is a schematic diagram of the internal structure of the sheath (second state) disclosed in the embodiments of this application;
[0020] Figure 8 yes Figure 7 A magnified view of a section at point C;
[0021] Figure 9This is a schematic diagram of the sealing cap structure disclosed in the embodiments of this application;
[0022] Figure 10 This is a schematic diagram of the structure of the guide tube disclosed in the embodiments of this application;
[0023] Figure 11 This is a schematic diagram of the guide tube disclosed in an embodiment of this application from another perspective.
[0024] In the picture:
[0025] 10. Handle; 20. Insertion part; 30. Negative pressure source; 100. Sheath seat; 110. Negative pressure interface; 120. Tube body; 130. Cavity; 131. Second sealing surface; 200. Sealing cap; 210. Adjustment channel; 211. First sealing surface; 220. Elastic column; 230. Stop surface; 300. Guide tube; 310. Upper sealing ring; 320. Lower sealing ring; 321. Connecting part; 322. First mating part; 323. Second mating part; 324. Circumventing groove; 330. Guide surface; 340. Abutment surface. Detailed Implementation
[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.
[0027] In the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.
[0028] In various embodiments of this application, "proximal end" and "distal end" refer to the position of the endoscope and its accessories relative to the user in the usage environment. The end closer to the user is designated as the "proximal end", and the end farther from the user is designated as the "distal end".
[0029] Existing sheaths include a sheath base, a flexible sealing ring, and a sealing cap. The sheath base has a negative pressure interface and a tube body. The tube body provides a stable channel for inserting the endoscope. The negative pressure interface is used to connect to a negative pressure source, and the opening switch on the negative pressure interface controls the negative pressure suction pressure to aspirate samples (such as body fluids, stones, human tissue, etc.) from the human body, allowing the sample to be drawn out of the body through the gap between the insertion part and the tube body. To ensure stable negative pressure suction, existing technology uses the sealing cap to fix the flexible sealing ring to the sheath base. The insertion part passes through the flexible sealing ring before entering the tube body, and the flexible sealing ring seals with the insertion part to prevent negative pressure leakage during suction. However, in actual operation, on the one hand, due to the uncontrollable size of the sample and the pressure of the tube body from the body's natural cavities, sample blockage can easily occur in the sheath body. In this case, it is necessary to insert the endoscope... The insertion section is pulled out of the tube body. After the blockage is cleared, the endoscope insertion section is reinserted into the tube body to continue the surgery. This creates a rigid requirement that the endoscope insertion section needs to be inserted into the sheath multiple times in a single operation. On the other hand, because there is a cavity between the sealing cap and the sheath seat to accommodate the sample, there is a suspension space between the flexible sealing ring and the tube body. The sealing fit between the flexible sealing ring and the insertion section will hinder the axial force transmission of the insertion section, making the insertion section prone to bending near the proximal end of the flexible sealing ring. This causes the distal end of the insertion section to deviate from the proximal end of the tube body, increasing the difficulty of insertion. Operators need to expend extra effort to ensure that the endoscope insertion section is accurately and quickly inserted into the sheath body, which also increases the operation time. If the sealing fit between the flexible sealing ring and the insertion section is removed, negative pressure leakage will occur during negative pressure aspiration, making it difficult to accurately control the negative pressure aspiration force on the sample and increasing the surgical risk.
[0030] To address this, this application provides a sheath and endoscope assembly. A guide tube directly guides the insertion part to the proximal port of the tube body, shortening the suspended distance of the insertion part from the lower sealing ring to the proximal port of the tube body. This reduces the difficulty of inserting the insertion part into the sheath body. Simultaneously, based on axial sliding control of the guide tube on the sealing cap, the opening of the cavity connecting to the external environment via the regulating channel can be changed when switching the guide tube between the first and second states, achieving flexible control of the negative pressure suction pressure. In the second state, the sealing fit of the lower sealing ring on the insertion part is released, reducing the resistance to rapid insertion / removal of the insertion part from the sheath. Furthermore, the cooperation between the lower sealing ring and the second sealing surface blocks the connection between the negative pressure interface and the tube body, and also blocks the connection between the tube body and the negative pressure source. Compared to existing technologies, this eliminates the switch structure on the existing negative pressure interface, simplifies the sheath structure, and achieves simultaneous control of negative pressure regulation and insertion part sealing in one structure, effectively improving the ease of use of the sheath and increasing the comfort of using the endoscope assembly. Specific embodiments are described below.
[0031] Example 1
[0032] This embodiment provides an endoscope assembly, such as Figure 1 As shown, the device includes an endoscope and a sheath. The endoscope is existing technology. The structure and function of the endoscope are briefly described below. The endoscope includes a handle 10 and an insertion part 20. A lever structure is provided on the handle 10, which controls the directional bending of the distal end of the insertion part 20. An illumination unit and a camera module are provided on the distal end surface of the insertion part 20. The illumination unit is used to provide illumination light, and the camera module is used to acquire image information of the internal cavity of the distal end of the insertion part 20. In some embodiments, an instrument channel can be provided on the insertion part 20. The proximal port of the instrument channel is located on the handle 10, and the distal port of the instrument channel is located at the distal end of the insertion part 20. The instrument channel is used to allow surgical instruments or perfusion fluid to pass through. The surgical instruments are existing technology and can be injection needles, dilators, stents, stone retrieval baskets, optical fibers, biopsy forceps, hemostatic clips, etc., without specific limitations. The perfusion fluid can be physiological saline, a drug, or a gas, without specific limitations.
[0033] like Figures 2-8 As shown, the sheath includes a sheath seat 100 and a guide tube 300. The sheath seat 100 is provided with a negative pressure interface 110, which is used to connect to a negative pressure source 30. The negative pressure source 30 can be a negative pressure pump, a manual negative pressure device (such as a pneumatic manual suction device, a piston manual suction device), a centralized negative pressure air supply system, etc., which are not specifically limited here. The distal end of the sheath seat 100 is provided with a tube body 120, which is used to pass through the endoscope insertion part 20. The proximal end of the sheath seat 100 is provided with a sealing cap 200, which is connected to the sheath seat 100. The sealing cap 200 and the sheath seat 100 cooperate to form a cavity 130. The negative pressure interface 110 communicates with the tube body 120 through the cavity 130. The middle part of the sealing cap 200 is provided with a regulating channel 210 communicating with the cavity 130, such as... Figure 9 As shown, the distal end of the control channel 210 is provided with a first sealing surface 211, and the sheath seat 100 is provided with a second sealing surface 131 on the inner wall near the tube body 120. The guide tube 300 is used to pass through the endoscope insertion part 20, and the distal end of the guide tube 300 passes through the control channel 210 and is positioned near the tube body 120; Figure 10 and Figure 11 As shown, the guide tube 300 is provided with an upper sealing ring 310 and a lower sealing ring 320. The guide tube 300 and the control channel 210 have an axial sliding stroke, which includes a first state and a second state; in the first state, as... Figure 5 and Figure 6 As shown, the upper sealing ring 310 and the first sealing surface 211 are sealed together, the lower sealing ring 320 and the second sealing surface 131 have a first gap, and the lower sealing ring 320 and the endoscope insertion part 20 are sealed together; in the second state, as Figure 7 and Figure 8 As shown, the lower sealing ring 320 expands to meet the second sealing surface 131, and the lower sealing ring 320 expands and deforms to form a second gap with the endoscope insertion part 20. A third gap exists between the upper sealing ring 310 and the first sealing surface 211. During assembly, the endoscope insertion part 20 passes sequentially through the guide tube 300, the cavity 130, and the tube body 120.
[0034] Based on the structural design of the aforementioned sealing cap, when performing surgical procedures using the endoscopic assembly, for example, such as laser lithotripsy within the renal calyx, the gap between the tube body 120 and the insertion portion 20 serves as the aspiration channel. In this case, the guide tube 300 can be controlled to be in a first state within the control channel 210, such as... Figure 5 and Figure 6 As shown, the upper sealing ring 310 and the first sealing surface 211 abut against each other for a sealing fit. Simultaneously, under normal conditions, the lower sealing ring 320 abuts against the peripheral wall of the insertion part 20 for a sealing fit, forming a sealed suction environment on the sheath seat 100. The negative pressure interface 110 is connected to the suction channel only through the cavity 130, allowing the suction pressure of the negative pressure source 30 to generate the maximum pressure differential effect, suctioning out the stones in the renal calyx. When the negative pressure suction pressure needs to be adjusted according to changes in the condition within the renal calyx, the guide tube 300 is controlled to slide axially towards the distal end. This allows the upper sealing ring 310 and the first sealing surface 211 to be separated, enabling the cavity 130 to connect with the external environment through the control channel 210, thereby reducing the negative pressure suction pressure of the suction channel. Furthermore, as the guide tube 300 slides axially towards the distal end, the opening of the cavity 130 connecting with the external environment through the control channel 210 increases, resulting in a smaller negative pressure suction pressure in the suction channel. When gravel blocks the suction channel, the guide tube 300 can be controlled to slide axially along the control channel 210 to the second state, such as... Figure 7 and Figure 8As shown, at this time, the lower sealing ring 320 expands and connects with the second sealing surface 131, and the lower sealing ring 320 expands and deforms to form a second gap with the endoscope insertion part 20. This releases the sealing fit between the lower sealing ring 320 and the insertion part 20, reducing the resistance to rapid insertion / removal of the insertion part 20 from the sheath. Furthermore, the cooperation between the lower sealing ring 320 and the second sealing surface 131 blocks the connection between the negative pressure interface 110 and the tube body 120, isolating the suction channel and locking the second state. This eliminates the need for the operator to continuously increase the driving force to maintain the second state, reducing operational pressure. Simultaneously, a third gap exists between the upper sealing ring 310 and the first sealing surface 211, allowing the negative pressure interface 110 to connect with the external environment through the control channel 210. The negative pressure suction pressure in the suction channel is eliminated, which has an adverse effect on the insertion / removal of the insertion part 20. This further improves the efficiency of blockage removal and the ease of use of the sheath. After the insertion part 20 is removed from the tube body 120, the system switches to the first state, keeping the insertion part 20 in the guide tube 300. The sample blocked in the tube body 120 is suctioned out under the maximum suction negative pressure. After the blockage in the tube body 120 is removed, the insertion part 20 can be quickly reinserted into the tube body 120 to continue the lithotripsy operation. This eliminates the need for the switch structure on the existing negative pressure interface 110, simplifies the sheath structure, and enables simultaneous control of both negative pressure regulation and sealing control of the insertion part 20 by a single guide tube 300. This effectively improves the ease of use of the sheath and increases the comfort of using the endoscope assembly.
[0035] In some embodiments, to reduce operating negative pressure, an abutment surface 340 can be provided at the proximal end of the guide tube 300. The sheath also includes an elastic post 220. The abutment surface 340 is connected to the sealing cap 200 via the elastic post 220, so that the sliding stroke is normally in a first state or a second state. In some preferred embodiments, the elastic post 220 can be a medical-grade stainless steel spring or a silicone elastomer, with its axis parallel to the sliding direction of the guide tube 300. The abutment surface 340 is an annular flange formed by extending the inner wall of the guide tube 300 towards the center. The proximal end of the elastic post 220 is detachably connected to the inner wall of the adjustment channel 210 of the sealing cap 200 via a snap-fit structure, and the distal end is sleeved on the outer periphery of the annular flange and fixed by hot-melt welding. When the elastic column 220 is in its naturally extended state, the axial thrust it provides keeps the guide tube 300 in the first state. At this time, the upper sealing ring 310 forms a contact seal with the first sealing surface 211, and the lower sealing ring 320 maintains an interference fit with the insertion part 20 because it is not subjected to radial compression. When the axial thrust is applied to push the guide tube 300 to move to the distal end, the elastic column 220 is compressed and stores elastic potential energy. After the guide tube 300 switches to the second state, the lower sealing ring 320 undergoes drum-shaped deformation due to radial compression from the second sealing surface 131, and its inner diameter expands to form a second gap. At the same time, the upper sealing ring 310 separates from the first sealing surface 211 to form a third gap, thereby realizing the switching of the negative pressure passage and the synchronous adjustment of the sealing state of the insertion part 20.
[0036] In some preferred embodiments, under normal conditions, the elastic column 220 is in a compressed state. The elastic column 220, the upper sealing ring 310, and the first sealing surface 211 cooperate to keep the sliding stroke in a first state under normal conditions. When the external force is removed, the elastic column 220 releases its stored elastic potential energy, pushing the guide tube 300 to return to its original position axially towards the proximal end until the upper sealing ring 310 re-abuts and seals against the first sealing surface 211, thus automatically restoring the sliding stroke to the first state. This design ensures that a sealed environment for negative pressure aspiration can be maintained without continuously applying external force during surgical operations. Especially in scenarios requiring stable negative pressure, such as lithotripsy aspiration, it can effectively reduce the risk of operational errors. The compression amount of the elastic column 220 can be set according to clinical needs by adjusting its free length or elastic coefficient. For example, when targeting the endoscope insertion part 20 with a diameter of 3mm-5mm, the pre-compression amount of the elastic column 220 is preferably set to 2mm-3mm to provide an axial thrust of 0.5N-1N, which ensures the sealing reliability in the first state and avoids the guide tube sliding difficulty due to excessive thrust.
[0037] In some preferred embodiments, under normal conditions, the elastic column 220 is in a stretched state. The elastic column 220, the lower sealing ring 320, and the second sealing surface 131 cooperate to ensure that the sliding stroke is in a second state under normal conditions. At this time, both ends of the elastic column 220 are fixedly connected to the abutment surfaces 340 of the sealing cover 200 and the guide tube 300, respectively. Its initial length is less than the working length after installation, thereby pulling the guide tube to the distal end through continuous tensile force. Specifically, the elastic column 220 can be made of nickel-titanium alloy wire or polyurethane elastic rope with high elastic recovery performance. Its distal end is fixed to the annular flange of the inner wall of the guide tube 300 by circumferential positioning through a keyway structure, and the proximal end passes through the pre-set guide hole on the sealing cover 200 and is locked by a nut. The inner wall of the guide hole is provided with a polytetrafluoroethylene wear-resistant bushing to reduce frictional loss during the reciprocating motion of the elastic column. Under normal conditions, the tensile force of the elastic column 220 keeps the lower sealing ring 320 in an expanded contact with the second sealing surface 131. The drum-shaped deformation of the lower sealing ring 320 due to radial compression creates a second gap, while the upper sealing ring 310 maintains a third gap with the first sealing surface 211. At this time, the cavity 130 is connected to the external environment through the control channel 210, and there is no suction force at the distal end of the tube 120. When negative pressure suction needs to be activated, the operator pushes the guide tube 300 towards the proximal end to overcome the tensile force of the elastic column. The guide tube 300 slides axially along the control channel 210, and the lower sealing ring 320 gradually detaches from the compression of the second sealing surface 131 and returns to its natural state. Its inner diameter shrinks to form a seal with the insertion part 20 through an interference fit. At the same time, the upper sealing ring 310 moves towards the proximal end and abuts against the first sealing surface 211 to form a seal, completing the switch to the first state. This design is particularly suitable for scenarios that require frequent insertion and removal of the insertion part 20. The second state under normal conditions can reduce insertion and removal resistance, while a simple axial thrust can quickly switch to negative pressure suction mode, improving the flexibility of surgical operations.
[0038] In some embodiments, to reduce the number of sheath components, the resilient post 220 and the sealing cap 200 can be integrated into one unit.
[0039] In other embodiments, to reduce the number of sheath components, the elastic post 220 and the guide tube 300 can be integrated into one unit.
[0040] In some embodiments, to facilitate control of the directional deformation of the elastic column 220, the elastic column 220 can be configured as a pre-bent structure, with its bending direction oriented towards the axis of the guide tube 300. For example, a pre-set bending angle of 15°-30° along the radial direction of the guide tube 300 is provided. This allows the elastic column 220 to undergo directional deformation along the pre-set bending direction when subjected to axial pressure or tension, preventing the guide tube 300 from jamming or failing to seal due to unexpected lateral bending. The pre-bent structure can be prepared by a mold-forming process. During the molding process of the elastic column 220, a medical-grade nickel-titanium alloy wire or a stainless steel spring is placed in a mold with a specific curvature and heat-treated to form a stable lattice structure memory within the material, thereby maintaining the pre-set bending shape after deformation under stress. In practical applications, when the guide tube 300 slides along the axial direction, the pre-bent elastic column 220 will undergo elastic deformation along its bending direction. Its deformation force is mainly concentrated in the axial direction, reducing the influence of the radial component force on the sealing ring fitting accuracy, ensuring the fitting stability of the upper sealing ring 310 with the first sealing surface 211 and the lower sealing ring 320 with the second sealing surface 131, while reducing the operating resistance during the sliding process of the guide tube 300, making the state switching smoother.
[0041] In some embodiments, to achieve stable separation of the lower sealing ring 320 from the peripheral wall of the insertion portion 20 in the second state, the lower sealing ring 320 can be configured as a flexible sealing ring, such as... Figures 5-8As shown, the lower sealing ring 320 includes a connecting part 321, a first mating part 322, and a second mating part 323. The connecting part 321 is connected to the distal end of the guide tube 300. The first mating part 322 is correspondingly disposed with the peripheral wall of the guide tube 300. The first mating part 322 is used to expand and fit with the second sealing surface 131. The second mating part 323 protrudes from the distal end face of the guide tube 300. Under normal conditions, the inner diameter of the second mating part 323 is smaller than the diameter of the endoscope insertion part 20. Based on the above structural design, when the guide tube 300 is in the first state, the second mating part 323 tightly wraps around the outer peripheral wall of the insertion part 20 under its own elasticity, forming a radial interference seal, preventing the negative pressure in the cavity 130 from leaking through the gap between the insertion part 20 and the guide tube 300; when the guide tube 300 slides to the second state, the first mating part 322 contacts the second sealing surface 131 and is radially compressed, causing the second mating part 323 to expand outward, increasing the inner diameter of the second mating part 323 to be greater than the diameter of the insertion part 20, forming a stable second gap. In some preferred embodiments, the lower sealing ring 320 can be made of medical silicone, and the outer peripheral surface of its first mating part 322 is set as a conical surface structure, forming a conical surface fit with the conical inner wall of the second sealing surface 131. When the guide tube 300 slides axially, the conical guiding effect can make the first mating part 322 uniformly stressed and generate radial expansion, avoiding local stress concentration that could cause the lower sealing ring 320 to tear. The inner circumferential surface of the second mating part 323 may be provided with an annular groove, in which an elastic metal ring is embedded. This groove provides circumferential support when the second mating part 323 expands, preventing excessive deformation that could lead to sealing failure or a decrease in recovery performance. The connection between the connecting part 321 and the guide tube 300 may be achieved using an injection molding process, ensuring that the bonding strength meets the fatigue strength requirements of repeated insertion and removal. The mating surface is provided with a barbed structure to enhance axial tensile strength and prevent the lower sealing ring 320 from falling off the guide tube during long-term use.
[0042] Specifically, when the guide tube 300 slides axially toward the distal end until the first mating part 322 expands and engages with the second sealing surface 131, the second mating part 323 is pulled by the first mating part 322 to produce radial expansion deformation, so as to achieve that in the second state, the lower sealing ring 320 expands and engages with the second sealing surface 131, and the lower sealing ring 320 expands and deforms to form a second gap with the endoscope insertion part 20.
[0043] In some embodiments, to facilitate the stable directional deformation of the lower sealing ring 320 in the second state, a relief groove 324 can be provided at the proximal end of the lower sealing ring 320. The relief groove 324 is spaced apart circumferentially along the lower sealing ring 320 or continuously distributed in a ring, with a depth of 1 / 3-1 / 2 of the wall thickness of the lower sealing ring 320 and a width of 0.5mm-1mm. Specifically, the relief groove 324 is formed at the proximal end face of the connecting portion 321 near the first mating portion 322. When the first mating portion 322 is radially compressed by the second sealing surface 131, the material at the relief groove 324 preferentially undergoes elastic deformation due to the thinning of its thickness, providing a preset deformation path for the second mating portion 323 to expand outward, and preventing the lower sealing ring 320 from twisting or wrinkling during the deformation process. In some preferred embodiments, the cross-section of the clearance groove 324 is V-shaped or U-shaped. The apex angle of the V-shaped groove is set to 60°-90°, and the bottom of the groove is provided with a rounded transition structure to reduce stress concentration. The radius of the U-shaped groove is adapted to the elastic modulus of the material of the lower sealing ring 320. For example, when using medical silicone with a Shore hardness of 50A-70A, the radius of the U-shaped groove is preferably 0.3mm-0.5mm to ensure that the groove wall is not prone to cracking during repeated deformation. By setting the clearance groove 324, the expansion deformation of the lower sealing ring 320 in the second state can be concentrated in the second mating part 323, ensuring that its inner diameter increases uniformly and forming a stable annular second gap. At the same time, it avoids the misalignment of the mating surface between the first mating part 322 and the second sealing surface 131, maintaining the reliability of the expansion seal.
[0044] In some embodiments, to facilitate quick insertion of the endoscope insertion portion 20 into the guide tube 300, such as... Figure 10 and Figure 11As shown, a guide surface 330 can be provided at the proximal end of the guide tube 300. The guide surface 330 is a tapered transition structure that gradually widens towards the proximal end, with a tapered angle of 30°-60° and a tapered surface length of 5mm-8mm. The inner surface of the guide surface 330 is polished to form a smooth surface with Ra≤0.8μm. Specifically, the proximal edge of the guide surface 330 is provided with a rounded transition with a radius of 0.5mm-1mm to avoid sharp edges scratching the outer coating of the endoscope insertion part 20. The connection between the tapered surface and the inner wall of the guide tube 300 adopts an arc transition with a transition radius of 1mm-2mm to ensure that there is no step obstruction when the insertion part 20 enters the inner cavity of the guide tube 300 from the guide surface 330. In some preferred embodiments, the inner surface of the guide surface 330 may be coated with a medical-grade superhydrophobic coating, such as a polydimethylsiloxane (PDMS) coating, with a static contact angle ≥110°. This effectively reduces the coefficient of friction between the insertion part 20 and the guide surface 330, reducing insertion resistance by more than 30%. Simultaneously, the guide surface 330 may be made of the same material as the main body of the guide tube 300 or a lower-hardness medical elastic material, such as silicone. It may be integrally molded with the guide tube using a two-color injection molding process, ensuring both structural strength and elastic cushioning to prevent hard impact damage caused by operational errors during insertion.
[0045] Specifically, the guide tube 300, the control channel 210, and the tube body 120 are coaxially arranged to ensure that the endoscope insertion part 20 can quickly and accurately enter the proximal port of the tube body 120 from the guide tube 300.
[0046] In some embodiments, to limit the deformation of the lower sealing ring 320 when switching to the second state and improve its service life, a stop surface 230 can be provided at the proximal end of the sealing cover 200. The stop surface 230 is used to cooperate with the proximal end of the guide tube 300 to limit the sliding stroke of the guide tube 300 along the distal end of the control channel. Specifically, the stop surface 230 can be set as an annular boss formed by extending the proximal sidewall of the sealing cover 200 along the axial direction, with a radial width of 2mm-4mm and an axial height of 1mm-2mm. The distal end face of the boss is correspondingly set with the annular shoulder at the proximal end of the guide tube 300. When the guide tube 300 slides to the distal end along the control channel to the second state, the annular shoulder and the distal end face of the annular boss form a surface contact abutment, thereby limiting the guide tube 300 from continuing to move distally. In some preferred embodiments, an annular silicone buffer pad may be embedded in the distal end face of the annular boss. The buffer pad has a thickness of 0.3mm-0.5mm, a Shore hardness of 30A-40A, and its surface is textured with anti-slip material. This absorbs the impact force when the guide tube 300 slides into place, reducing noise from component collisions, and enhances the limiting stability through friction, preventing accidental slippage of the guide tube due to vibration during surgery. The proximal surface of the annular shoulder may have an annular groove adapted to the buffer pad. The groove depth is half the thickness of the buffer pad. When in contact, the buffer pad partially embeds into the groove, forming a concave-convex fit structure, further improving the reliability of the limiting. The position of the stop surface 230 needs to be precisely set according to the maximum allowable deformation of the lower sealing ring 320. For example, when the lower sealing ring is made of medical silicone with a Shore hardness of 60A, its maximum radial expansion is designed to be 15%-20% of the diameter of the insertion part. By calculating the sliding distance of the guide tube 300 from the first state to the second state, the annular boss is set at the corresponding end point of the stroke to ensure that the deformation of the lower sealing ring 320 is always within the elastic recovery range, and to avoid material fatigue failure due to excessive stretching.
[0047] The endoscope provided in this application embodiment can be a nephroscope, or a bronchoscope, esophagoscope, gastroscope, colonoscope, otoscope, rhinoscope, oral endoscope, laryngoscope, colposcope, laparoscope, arthroscope, etc. This application embodiment does not specifically limit the type of endoscope.
[0048] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.
[0049] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.
Claims
1. A sheath, characterized in that, include: The sheath seat has a negative pressure interface, a tube body at the distal end of the sheath seat for inserting an endoscope, a sealing cap at the proximal end of the sheath seat, and the sealing cap and the sheath seat forming a cavity. The negative pressure interface communicates with the tube body through the cavity. The sealing cap has an adjustment channel communicating with the cavity in the middle. The distal end of the adjustment channel has a first sealing surface. The sheath seat has a second sealing surface on the inner wall near the tube body. A guide tube is provided for inserting an endoscope into the endoscope. The distal end of the guide tube passes through the control channel and is positioned close to the tube body. An upper sealing ring and a lower sealing ring are provided on the guide tube. The guide tube and the control channel have an axial sliding stroke, which includes a first state and a second state. In the first state, the upper sealing ring and the first sealing surface are sealed together, and there is a first gap between the lower sealing ring and the second sealing surface. The lower sealing ring and the endoscope insertion part are sealed together. In the second state, the lower sealing ring and the second sealing surface are expanded together, and the expanded deformation of the lower sealing ring forms a second gap with the endoscope insertion part. There is a third gap between the upper sealing ring and the first sealing surface.
2. The sheath according to claim 1, characterized in that, The guide tube has an abutment surface at its proximal end, and the sheath also includes an elastic column. The abutment surface is connected to the sealing cap through the elastic column, so that the sliding stroke is normally in a first state or a second state.
3. A sheath according to claim 2, characterized in that, Under normal conditions, the elastic column is in a compressed state, and the elastic column, the upper sealing ring, and the first sealing surface cooperate to ensure that the sliding stroke is in the first state under normal conditions. And / or, under normal conditions, the elastic column is in a stretched state, and the elastic column, the lower sealing ring, and the second sealing surface cooperate to ensure that the sliding stroke is in the second state under normal conditions.
4. A sheath according to claim 2, characterized in that, The elastic column and sealing cap are integrated into one unit; And / or, the elastic column and the guide tube are integrated into one unit; And / or, the elastic column is a pre-bent structure.
5. A sheath according to any one of claims 1 to 4, characterized in that, The lower sealing ring is a flexible sealing ring, which includes a connecting part, a first mating part, and a second mating part. The connecting part is connected to the distal end of the guide tube. The first mating part is correspondingly arranged with the peripheral wall of the guide tube. The first mating part is used to expand and fit with the second sealing surface. The second mating part protrudes from the distal end face of the guide tube. Under normal conditions, the inner diameter of the second mating part is smaller than the diameter of the endoscope insertion part.
6. A sheath according to claim 5, characterized in that, When the guide tube slides axially toward the distal end until the first mating part and the second sealing surface expand and fit together, the second mating part is pulled by the first mating part to produce radial expansion deformation, so as to achieve the second state, where the lower sealing ring expands and fits with the second sealing surface, and the lower sealing ring expands and deforms to form a second gap with the endoscope insertion part.
7. A sheath according to claim 5, characterized in that, The lower sealing ring has a clearance groove at its near end.
8. A sheath according to any one of claims 1 to 4, characterized in that, The guide tube has a guide surface at its near port. And / or, the guide tube, control channel and tube body are coaxially arranged.
9. A sheath according to any one of claims 1 to 4, characterized in that, The sealing cap has a stop surface at its proximal end, which is used to cooperate with the proximal end of the guide tube to limit the sliding stroke of the guide tube along the distal end of the control channel.
10. An endoscope assembly, characterized in that, It includes an endoscope and a sheath as described in any one of claims 1 to 9, wherein the insertion portion of the endoscope is sequentially disposed in a guide tube, a cavity, and a tube body.