Snare for endoscopy

Abstract

The present application relates to a kind of snare cutting knives for endoscope, including proximal handle, tube body assembly, cutting assembly and limiting component;Proximal handle is equipped with limiting sliding slot;The proximal end of tube body assembly is connected with proximal handle, and the distal end of tube body assembly is equipped with insulating protection tube;Cutting assembly includes cutting ring and cutting head, and cutting head is set to the distal end of cutting ring;Limiting component includes sliding part and limiting control wire, sliding part is slidably arranged in limiting sliding slot, and the proximal end of limiting control wire is fixedly connected with sliding part, and sliding part is used to drive limiting control wire axial movement;When limiting control wire moves to the distal end of insulating protection tube, cutting head and insulating protection tube abut each other and are fixed;When limiting control wire exits insulating protection tube, cutting head can continue to move relative to insulating protection tube.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical devices for interventional procedures, in particular to a snare cutting knife for endoscopy. BACKGROUND

[0002] Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are important surgical methods for treating early gastrointestinal tumors. Among them, EMR is a treatment method developed on the basis of polypectomy and mucosal injection, which can completely remove the lesion tissue and reduce the occurrence of complications such as bleeding and perforation; and ESD can achieve one-time bulk resection of large lesions, providing complete pathological information and having the advantage of low postoperative recurrence rate.

[0003] With the development of endoscopic intervention technology, argon plasma coagulation (APC) under endoscopy has been widely used in the treatment of gastrointestinal polyps due to its small trauma, speed, and good patient tolerance.

[0004] In the above surgical procedures, a snare cutting knife is an important surgical instrument that integrates cutting, snare, and coagulation functions. However, the existing snare cutting knife has the problem of difficulty in accurately controlling the length of the knife head. When manually adjusting the length of the knife head, there is a large error, and when the length of the knife head is too long, it is easy to cause intraoperative perforation, endangering patient safety; and if the length of the knife head is too short, it will affect the cutting efficiency and prolong the operation time.

[0005] In particular, during APC surgery, the existing snare cutting knife has a big problem in retracting the knife head into the protection tube. If the knife head is retracted too much, it will affect the ionization effect of argon, resulting in insufficient coagulation; if the knife head is not fully retracted, it may cause injury or perforation to the patient.

[0006] Therefore, how to accurately control the length of the knife head to improve surgical safety and operational efficiency has become a technical problem to be solved in the field. SUMMARY

[0007] The present application discloses a snare cutting knife for endoscopy, which aims to solve the technical problems existing in the prior art.

[0008] In one embodiment, the present application provides a snare cutting knife for endoscopy, which comprises a proximal handle, a tube assembly, a cutting assembly, and a limiting assembly.

[0009] A limiting sliding groove is provided on the proximal handle.

[0010] The proximal end of the tube assembly is connected to the proximal handle, and the distal end of the tube assembly is provided with an insulating protection tube.

[0011] The cutting assembly comprises a cutting ring and a cutting head, and the cutting head is arranged at the distal end of the cutting ring.

[0012] The limiting assembly comprises a sliding part and a limiting control wire, the sliding part is slidingly arranged in a limiting sliding groove, the proximal end of the limiting control wire is fixedly connected with the sliding part, and the sliding part is used for driving the limiting control wire to move axially;

[0013] When the limiting control wire moves to the distal end of the insulation protection tube, the cutting head abuts against and is fixed with the insulation protection tube; when the limiting control wire exits the insulation protection tube, the cutting head can continue to move relative to the insulation protection tube.

[0014] As a preferred technical solution, the inner diameter of the insulation protection tube is greater than the maximum outer diameter of the cutting head and less than the sum of the maximum outer diameter of the cutting head and the outer diameter of the limiting control wire, so that when the limiting control wire is located at the distal end of the insulation protection tube, the cutting head and the limiting control wire form an interference fit in the inner diameter direction of the insulation protection tube.

[0015] As a preferred technical solution, the distal end of the limiting control wire is provided with a stepped portion, the inner diameter of the insulation protection tube is greater than the maximum outer diameter of the cutting head, and the cutting head has an abutting portion;

[0016] When the limiting control wire moves to the distal end of the insulation protection tube, the abutting portion of the cutting head abuts against the stepped portion of the limiting control wire to limit the axial displacement of the cutting head in the insulation protection tube.

[0017] As a preferred technical solution, the limiting sliding groove extends along the axial direction of the proximal handle, the sliding part comprises a pushing block and a sliding rod, the pushing block is arranged on the outer side of the proximal handle, the sliding rod is arranged in the limiting sliding groove and connected with the pushing block, the proximal end of the limiting control wire is fixed to the distal end of the sliding rod, and the axial movement of the pushing block is used to drive the limiting control wire to move axially.

[0018] As a preferred technical solution, the pipe body assembly comprises an outer pipe and an inner sleeve, the proximal end of the outer pipe is fixedly connected with the proximal handle, the distal end of the outer pipe is fixedly connected with the insulation protection tube, the inner sleeve is coaxially arranged in the outer pipe, the cutting assembly is axially arranged in the inner sleeve, and the limiting control wire is arranged in the gap between the inner sleeve and the outer pipe.

[0019] As a preferred technical solution, the pipe body assembly further comprises a guide pipe, the guide pipe is arranged in parallel between the inner sleeve and the outer pipe, the limiting control wire is arranged in the guide pipe and can move axially along the guide pipe.

[0020] As a preferred technical solution, a plurality of flexible slits are arranged on the pipe wall of the guide pipe and spirally distributed along the circumferential direction of the guide pipe, so that the guide pipe has a bendable performance.

[0021] As a preferred technical solution, an axial extending and through guide channel is arranged in the inner sleeve, the limiting control wire is arranged in the guide channel and can move axially along the guide channel.

[0022] As a preferred technical solution, the guide channel is configured as a closed channel arranged in the inner sleeve wall, or a groove arranged in the inner sleeve wall and having an opening in the circumferential direction.

[0023] As a preferred technical solution, the inner sleeve comprises a flexible wall structure in a spiral shape, so that the inner sleeve has a bendable performance.

[0024] As a preferred technical solution, the distal end of the limiting control wire is provided with a limiting piece, the outer diameter of the limiting piece is greater than the gap between the inner sleeve and the outer tube, and the limiting piece can abut against the proximal end of the inner sleeve to limit the maximum distance of the limiting control wire moving to the distal end.

[0025] The technical solution adopted by the present application can achieve the following beneficial effects:

[0026] The present application mainly provides a snare cutting knife for endoscopy. In an embodiment of the present application, the precise control of the position of the cutting head is realized through the cooperation of the limiting assembly and the cutting assembly. Specifically, when the limiting control wire moves to the distal end of the insulating protection tube, the axial limiting of the cutting head relative to the insulating protection tube is realized through the interference cooperation or step abutment structure between the cutting head and the limiting control wire, which not only avoids the excessive retraction of the cutting head affecting the electrocoagulation effect, but also prevents the damage to the human body caused by the exposure of the cutting head outside the protection tube.

[0027] Further, in an embodiment of the present application, the inner sleeve and the guide structure are arranged in the tube assembly, which ensures the stable and reliable movement track of the limiting control wire. In particular, the limiting piece can be arranged at the distal end of the limiting control wire, which effectively prevents the excessive extension of the limiting control wire to the distal end through the abutment cooperation with the proximal end of the inner sleeve, so as to solve the problem of inaccurate position control of the cutting head in the prior art and ensure the safety and controllability of the surgical process. At the same time, the inner sleeve or the guide tube is arranged as a flexible structure, which gives the instrument good bending performance, so as to improve the flexibility of the surgical operation during the intervention. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows, which constitutes a part of the present application. The schematic embodiments of the present application and the description and explanation thereof do not constitute an improper limitation on the present application. In the drawings:

[0029] Figure 1 FIG. 1 is a structural schematic diagram of an endoscopic electrotome according to an embodiment of the present application;

[0030] Figure 2 FIG. 2 is a structural schematic diagram of the distal end of an endoscopic electrotome according to an embodiment of the present application;

[0031] Figure 3 Figure 6 is a schematic diagram of the distal end structure of the endoscopic electrotome according to an embodiment of the present application;

[0032] Figure 4 Figure 7 is a partial enlarged view of the proximal handle according to an embodiment of the present application;

[0033] Figure 5 Figure 8 is a schematic diagram of the sliding part according to an embodiment of the present application;

[0034] Figure 6 Figure 9 is a schematic diagram of the distal end structure of the endoscopic electrotome according to an embodiment of the present application;

[0035] Figure 7 Figure 10 is a schematic diagram of the distal end structure of the endoscopic electrotome according to an embodiment of the present application;

[0036] Figure 8 Figure 11 is a schematic diagram of the distal end structure of the endoscopic electrotome according to an embodiment of the present application;

[0037] Figure 9 Figure 12 is a sectional view of the inner sleeve according to an embodiment of the present application;

[0038] Figure 10 Figure 13 is a sectional view of the inner sleeve according to another embodiment of the present application.

[0039] BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Proximal handle 10, limiting sliding groove 11, pipe body assembly 20, outer pipe 21, inner sleeve 22, guide channel 221, insulating protection pipe 23, cutting assembly 30, cutting head 31, cutting ring 32, sliding part 41, pushing block 411, sliding rod 412, limiting control wire 42, step part 421, guide pipe 43, limiting member 44. DETAILED DESCRIPTION

[0041] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described below in conjunction with specific embodiments of the present application and corresponding drawings. In the description of the present application, it should be noted that the term “or” is generally used in the sense of including “and / or” unless the context clearly indicates otherwise.

[0042] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or magnetically connected; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. In addition, in the description of the present application, the terms "first", "second" and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0043] In particular, in the description of the present application, those skilled in the art should understand that unless otherwise explicitly specified and limited, the terms "proximal end" and "distal end" are relative to the operator; the "proximal end" is the end of the snare cutting knife for endoscope closer to the user in one-dimensional direction when being operated, and the "distal end" is the end of the snare cutting knife for endoscope farther away from the user in one-dimensional direction when being operated. And those skilled in the art should understand that the "far" and "near" do not refer to the three-dimensional spatial straight distance from the user.

[0044] Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0045] In the current clinical application, the snare cutting knife is faced with the problem that the position of the cutting head is difficult to control accurately. When the cutting head needs to be retracted into the protection tube, if the retraction position is too deep, the ionization effect of argon gas will be reduced, affecting the hemostatic effect; if the retraction position is insufficient, the cutting head is easy to cause damage to human tissues.

[0046] Reference Figure 1 Figure 10 To solve the problems in the prior art, the embodiments of the present application provide a snare cutting knife for endoscope, which can be applied to endoscopic resection surgery of early tumors and lesions in the digestive tract. Specifically, the snare cutting knife for endoscope can be inserted into the human body cavity through the working channel of the endoscope to perform resection operation on the gastrointestinal mucosa and submucosal lesion tissue, and can use high-frequency current to perform hemostatic treatment on the resection site, thereby achieving the purpose of minimally invasive treatment.

[0047] As Figure 1 ​In a preferred embodiment, the structure of the snare cutting knife for endoscopy at least includes a proximal handle 10, a tube assembly 20, a cutting assembly 30, and a limiting assembly. The proximal handle 10 is arranged at the proximal end of the entire snare cutting knife for endoscopy, and is located outside the human body during the operation, and is used for hand operation during the operation. The tube assembly 20 is connected with the proximal handle 10 and extends axially, and can be transported in the body cavity. The cutting assembly 30 is arranged in the tube assembly 20, and includes a cutting ring 32 and a cutting head 31. The cutting head 31 is arranged at the distal end of the cutting ring 32, and the two are used to perform the cutting operation. The limiting assembly is also arranged in the tube assembly 20, and is used to axially limit the cutting head 31, so as to avoid that the cutting head 31 is retracted too much to affect the effect of electrocoagulation, and at the same time, prevent the cutting head 31 from being exposed too much to cause damage to the human body.

[0048] In a preferred embodiment, the cutting ring 32 is a snare ring made of conductive metal wire, which has a certain flexibility and can form a ring structure when opened. The cutting head 31 is fixedly arranged at the distal end of the cutting ring 32, and is used to cut the target tissue under the condition of being electrified. In this embodiment, the cutting ring 32 can be switched between the open and closed states: when the cutting ring 32 is completely opened, it forms a ring structure to surround the tissue to be removed; when the cutting ring 32 is retracted, it can grasp and remove the target tissue.

[0049] In this embodiment, the specific structure and size specification of the cutting head 31 and the cutting ring 32 are not limited, and those skilled in the art can freely select appropriate structure and size parameters according to actual needs and specific application scenarios, as long as the cutting and hemostasis functions are met.

[0050] As Figure 2 In a preferred embodiment, the tube assembly 20 includes an outer tube 21 and an inner sleeve 22. The proximal end of the outer tube 21 is fixedly connected with the proximal handle 10. The distal end of the outer tube 21 is fixedly connected with an insulating protection tube 23. The inner sleeve 22 is coaxially sleeved in the outer tube 21. The cutting assembly 30 is axially arranged in the inner sleeve 22.

[0051] Specifically, the outer tube 21 is the outermost structure of the tube assembly 20, which has sufficient strength and flexibility to ensure the stability of the snare cutting knife for endoscopy during transportation. The inner sleeve 22 is used to provide axial guidance for the cutting assembly 30, and plays a supporting and protecting role when the cutting assembly 30 reciprocates.

[0052] In a preferred embodiment, the outer tube 21 can be configured as a sheath commonly used in interventional surgery; the inner sleeve 22 can be specifically configured as a flexible wall structure in a spiral shape, which is composed of a continuous spiral groove or spiral line, such as a spring structure, so that the inner sleeve 22 has good radial bending performance while maintaining sufficient axial strength, and such a spiral structure enables the inner sleeve 22 to deform correspondingly with the bending of the outer tube 21, thereby ensuring that the push rod can still reliably transmit the pushing force in a bent state.

[0053] In some alternative embodiments, the inner sleeve 22 can also be made of medical-grade flexible plastic materials such as polytetrafluoroethylene, polyethylene, polyurethane, etc., which have good bending performance by themselves, so it is not necessary to necessarily set a flexible wall structure in a spiral shape; or the sleeve 22 can also be a tubular structure woven by metal wires or high-strength fibers, which maintains the axial pushing force transmission capability and has good radial flexibility; in addition, the inner sleeve 22 can also be provided as other composite structures with bending performance, which will not be described one by one here, and those skilled in the art can select appropriate structure forms according to specific application requirements.

[0054] Preferably, the insulation protection tube 23 is fixed to the distal end of the outer tube 21 and is made of an insulating material, which on the one hand can provide insulation protection for the cutting head 31 to avoid unnecessary contact between the cutting head 31 and the surrounding tissue, and on the other hand can provide a channel for argon gas to ensure the stability of the ionization process, thereby improving the safety and hemostatic effect of the surgery.

[0055] In a preferred embodiment, the insulation protection tube 23 is a hollow tubular structure, the proximal end of which is fixedly connected to the distal end of the outer tube 21, and the distal end is provided with an opening. The inner diameter of the insulation protection tube 23 is greater than the outer diameter of the cutting assembly 30 to ensure that the cutting assembly 30 can move freely therein.

[0056] Preferably, the insulation protection tube 23 can be made of insulating materials such as ceramics and high-molecular materials. Among them, the high-molecular insulating material can be selected according to specific requirements, such as medical-grade high-molecular materials such as polytetrafluoroethylene and polyether ether ketone. The specific structure size and material of the insulation protection tube 23 are not specifically limited in this embodiment, and those skilled in the art can select appropriate structure forms and materials according to actual application requirements under the premise of ensuring insulation performance.

[0057] As Figure 2In a preferred embodiment, in order to achieve axial positioning of the cutting head 31, the limiting assembly adopts a combination structure of the sliding part 41 and the limiting control wire 42. Specifically, the limiting slide groove 11 is arranged on the proximal handle 10, and the sliding part 41 can axially slide in the limiting slide groove 11. The proximal end of the limiting control wire 42 is fixedly connected with the sliding part 41 and moves synchronously with the sliding part 41. The limiting assembly has two working states: when the operator pushes the sliding part 41 to the distal end, so that the limiting control wire 42 moves to the distal end of the insulating protection tube 23, the cutting head 31, the insulating protection tube 23 and the limiting control wire 42 abut and fix each other, so as to achieve axial positioning of the cutting head 31 relative to the insulating protection tube 23. In this state, the length of the cutting head 31 extending out of the insulating protection tube 23 can be controlled, which can avoid that the cutting head 31 extends too long to cause injury to the patient, and also can avoid that the cutting head 31 extends too short to affect the cutting efficiency; when the operator pulls the sliding part 41 to the proximal end, so that the limiting control wire 42 exits the insulating protection tube 23, the space in the insulating protection tube 23 is released, and the cutting head 31 can continue to move relative to the insulating protection tube 23, for example, can continue to move to the distal end and extend out of the insulating protection tube 23, and finally make the cutting ring 32 completely open to meet the surgical cutting demand.

[0058] Preferably, the inner diameter of the insulating protection tube 23 is greater than the maximum outer diameter of the cutting head 31, so as to ensure that the cutting head 31 can normally move axially in the insulating protection tube 23 and will not be stuck due to excessive size; the inner diameter of the insulating protection tube 23 is less than the sum of the maximum outer diameter of the cutting head 31 and the outer diameter of the limiting control wire 42, so that when the limiting control wire 42 is located at the distal end of the insulating protection tube 23, the limiting control wire 42 can occupy a part of the space inside the insulating protection tube 23, and the cutting head 31 and the limiting control wire 42 form an interference fit in the inner diameter direction of the insulating protection tube 23, at this time the cutting head 31 will be stuck by the limiting control wire 42 due to insufficient transverse space, so as to prevent the cutting head 31 from continuing to move to the distal end, thereby effectively preventing the cutting head 31 from excessively extending out of the insulating protection tube 23 and causing accidental damage to the surrounding tissues during the operation.

[0059] As Figure 3 In another preferred embodiment, the distal end of the limiting control wire 42 is provided with a stepped portion 421, the outer diameter of the stepped portion 421 is greater than the outer diameter of the main body of the limiting control wire 42, and the cutting head 31 is provided with an abutting portion matched with the stepped portion 421; when the limiting control wire 42 moves to the distal end of the insulating protection tube 23, the abutting portion of the cutting head 31 will axially abut with the stepped portion 421 of the limiting control wire 42, thereby preventing the cutting head 31 from continuing to move.

[0060] Specifically, the step portion 421 is configured as a block-shaped or columnar structure that limits the distal end of the control wire 42, and has an outer diameter larger than that of the main body of the control wire 42; correspondingly, an inwardly tapered conical surface is arranged on the inner wall of the distal end of the cutting head 31, which constitutes the abutting portion. When the control wire 42 moves to the distal end of the insulation protection tube 23, the conical surface of the cutting head 31 cannot pass through the step portion 421, thereby forming axial limiting, so as to prevent the cutting head 31 from continuing to move distally; after the cutting head 31 completes the tissue cutting, the cutting head 31 needs to be completely withdrawn, and then the control wire 42 is withdrawn proximally, the space at the distal end of the insulation protection tube 23 is released, at this time, the cutting head 31 and the cutting ring 32 can be pushed out distally again until the cutting ring 32 is completely opened, and the polyp or the like is removed.

[0061] As Figure 4 , Figure 5 In a preferred embodiment, a limiting sliding groove 11 is formed on the proximal handle 10 along the axial direction thereof, and the sliding portion 41 includes a pushing block 411 and a sliding rod 412. The pushing block 411 is arranged on the outer surface of the proximal handle 10, and is convenient for the operator to push and pull directly with fingers. The sliding rod 412 penetrates through the limiting sliding groove 11 and is fixedly connected with the pushing block 411, so that the movement of the pushing block 411 can drive the sliding rod 412 to synchronously slide in the limiting sliding groove 11. The proximal end of the control wire 42 is fixed to the distal end of the sliding rod 412, so as to realize the linkage of the pushing block 411, the sliding rod 412 and the control wire 42. When the operator pushes or pulls the pushing block 411, the control wire 42 can be driven to move axially correspondingly through the transmission of the sliding rod 412, so as to realize the control of the position of the cutting head 31.

[0062] Since the movement of the sliding portion 41 in the limiting sliding groove 11 directly determines the axial displacement of the control wire 42, preferably, the length of the limiting sliding groove 11 matches the expected moving distance of the control wire 42.

[0063] Specifically, the length of the limiting sliding groove 11 should meet the stroke distance required for the cutting head 31 to be completely retracted to the maximum extended position, which is determined by the specific requirements of the surgical operation, and needs to ensure that the cutting head 31 can be extended far enough to complete the cutting operation, and at the same time, will not be excessively extended to cause safety hazards.

[0064] As Figure 2 In a preferred embodiment, a certain annular gap is formed between the inner sleeve 22 and the outer tube 21, the control wire 42 is arranged in the gap and can freely move axially therein. When the inner sleeve 22 is bent, the annular gap will also change correspondingly, but since the gap exists, the axial movement of the control wire 42 in the gap can still be ensured to be unaffected.

[0065] In a preferred embodiment, the position-limiting control wire 42 is made of biocompatible material, which can be selected from nickel-titanium alloy, titanium or stainless steel, etc. Considering the requirement of miniaturization and the operational flexibility of surgical instruments, the diameter of the position-limiting control wire 42 can be selected from the range of 0.1-0.5 mm.

[0066] As Figure 6 In another preferred embodiment, a guide tube 43 is arranged between the inner sleeve 22 and the outer tube 21, which is parallel to the inner sleeve 22 and the outer tube 21, and is elastically fixed to the outer tube 21. A plurality of helical slits are formed on the wall of the guide tube 43, which are uniformly distributed in the circumferential direction of the guide tube 43 in a helical or twisted manner. The helical angle, width and length of each slit can be designed according to the required bending performance, which is not specifically limited herein. By arranging the helical slits, the guide tube 43 can obtain good bending deformation capability and can bend in coordination with the turning of the surgical instrument.

[0067] In some optional embodiments, the guide tube 43 can adopt various tube structure forms: the guide tube 43 can be a medical-grade flexible plastic tube made of polytetrafluoroethylene, polyethylene, polyurethane, etc.; it can also be a spring tube made of stainless steel wire or nickel-titanium alloy wire, which can obtain different bending characteristics by adjusting the density, wire diameter and material of the coil; it can also be a mesh tube structure woven by multiple metal wires or high-strength polymer fibers; or it can adopt a multi-layer composite structure, such as a woven layer in the inner layer and a flexible polymer coating in the outer layer, which can ensure mechanical strength and provide a smooth surface. The above-mentioned various forms of guide tube 43 can realize the function of bending in coordination with the surgical instrument, and the doctor can select the appropriate structure form according to the specific use requirement, which is not specifically limited in the present embodiment.

[0068] Further, the position-limiting control wire 42 is arranged in the guide tube 43 and can freely move axially in the lumen of the guide tube 43. On the one hand, the guide tube 43 provides a moving channel for the position-limiting control wire 42 to avoid interference with the inner sleeve 22 and the outer tube 21; on the other hand, since the guide tube 43 has bendable performance, when the surgical instrument bends, the guide tube 43 can bend and deform accordingly, thereby ensuring that the position-limiting control wire 42 is always in a constrained state, preventing it from being stuck or deformed at the bending part, so that the movement reliability of the position-limiting control wire 42 under various operating postures is ensured.

[0069] Preferably, the guide tube 43 is made of stainless steel, nickel-titanium alloy or other materials with good elasticity, and the inner diameter is greater than the outer diameter of the position-limiting control wire 42, preferably in the range of 0.15-0.6 mm.

[0070] As Figure 8In another preferred embodiment, the inner sleeve 22 is provided with an integrated guiding structure, specifically, the inner sleeve 22 is provided with an axially extending guiding channel 221 that is open at both ends and is configured to accommodate and guide the movement of the limiting control wire 42. Optionally, the guiding channel 221 can be configured in two forms:

[0071] In an optional embodiment, the guiding channel 221 is configured as a closed channel arranged in the wall of the inner sleeve 22, such as Figure 9 , specifically, an entirely closed elongated channel is formed in the wall of the inner sleeve 22, which extends from the proximal end to the distal end of the inner sleeve 22, forming a separate closed space, and the limiting control wire 42 is completely wrapped in the closed channel and can move axially therein. This design can maximize the protection and guidance of the limiting control wire 42, preventing it from interfering with other components;

[0072] In another optional embodiment, the guiding channel 221 is configured as a slot arranged in the wall of the inner sleeve 22 and having an opening in the circumferential direction, such as Figure 10 , although the slot is also axially extending, one side of the circumferential direction is open, and the limiting control wire 42 can be placed in the slot through the opening and move axially in the slot, making it more convenient to assemble and maintain the limiting control wire 42.

[0073] Preferably, the inner diameter of the guiding channel 221 is also greater than the outer diameter of the limiting control wire 42, preferably in the range of 0.15-0.6mm.

[0074] In a preferred embodiment, an axially extending guiding groove can be arranged on the inner wall of the insulating protection tube 23, and the guiding groove is used to guide the limiting control wire 42. The limiting control wire 42 can slide axially along the guiding groove, and through the guiding effect of the guiding groove, the movement of the limiting control wire 42 can be more stable and reliable, avoiding the deflection or jamming of the limiting control wire 42 during movement.

[0075] Preferably, the guiding groove of the insulating protection tube 23 can also extend to the portion of the outer tube 21 at the distal end.

[0076] Specifically, the cross-sectional shape of the guiding groove can be a V-shaped groove, a U-shaped groove, or other groove structures suitable for accommodating and guiding the limiting control wire 42.

[0077] In a preferred embodiment, the distal end of the limiting control wire 42 is provided with a limiting member 44, which can abut against the proximal end of the inner sleeve 22 to limit the maximum distance of the limiting control wire 42 moving distally, so as to limit the maximum distance of the limiting control wire 42 moving distally and prevent the limiting control wire 42 from moving excessively. The outer diameter of the limiting member 44 is greater than the gap between the inner sleeve 22 and the outer tube 21 in the above-mentioned embodiment, or greater than the inner diameter of the guide tube 43 in the above-mentioned embodiment, or greater than the inner diameter of the guide channel 221 in the above-mentioned embodiment, so as to effectively limit the limiting control wire 42. Figure 7 Figure 8

[0078] Preferably, the limiting member 44 can be configured as a block structure, such as a cuboid or rectangular cuboid structure; or a tubular structure, i.e. a structure similar to a short pipe; or a ring structure, similar to a thickened washer; or a spherical structure, which is convenient to form a point contact with the proximal end of the inner sleeve 22. Through the design of the limiting member 44 in different shapes, the movement distance of the limiting control wire 42 can be effectively controlled.

[0079] Preferably, the limiting member 44 can be fixedly connected with the distal end of the limiting control wire 42 by welding, gluing, clamping or the like, or integrally formed with the limiting control wire 42, so as to ensure reliable connection during use. The limiting member 44 is preferably made of stainless steel, titanium alloy or other materials with good mechanical strength and biocompatibility, so as to meet the use requirements of medical devices.

[0080] In specific use, the snare cutter for endoscope in any of the above-mentioned embodiments is inserted into the patient's body through the working channel of the endoscope and performs cutting operation on the diseased part. During the cutting process, the limiting control wire 42 can reliably fix the extension length of the cutting head 31 through cooperation with the insulating protection tube 23, so as to avoid the risk of patient injury caused by the cutting head 31 extending too long, or affect the cutting efficiency due to the cutting head 31 extending too short, and help to maintain the best cutting effect; further, in the application of argon plasma coagulation (APC), the snare cutter for endoscope provided by the embodiment can make the ionization of argon more stable, thereby improving the hemostatic effect.

[0081] The embodiments of the present application are described above in combination with the drawings, but the present application is not limited to the above-mentioned specific embodiments, which are only illustrative but not limiting. Those skilled in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, which all belong to the protection of the present application.​​

Claims

1. An endoscopic snare cutter, characterized in that, Includes a proximal handle, tube body assembly, cutting assembly, and limiting assembly; The proximal handle is provided with a limiting groove; The proximal end of the tube assembly is connected to the proximal handle, and the distal end of the tube assembly is provided with an insulating protective tube. The cutting assembly includes a cutting ring and a cutting head, wherein the cutting head is disposed at the distal end of the cutting ring; The limiting component includes a sliding part and a limiting control wire. The sliding part is slidably disposed in the limiting groove. The proximal end of the limiting control wire is fixedly connected to the sliding part. The sliding part is used to drive the limiting control wire to move axially. When the limiting control wire moves to the far end of the insulating protective tube, the inner wall of the far end of the limiting control wire abuts against the cutting head, and the outer wall of the far end of the limiting control wire abuts against the insulating protective tube, so that the cutting head, the limiting control wire, and the insulating protective tube abut against each other and are fixed; when the limiting control wire retracts from the insulating protective tube, the cutting head can continue to move relative to the insulating protective tube.

2. The endoscopic snare cutter according to claim 1, characterized in that, The inner diameter of the insulating protective tube is greater than the maximum outer diameter of the cutting head, and less than the sum of the maximum outer diameter of the cutting head and the outer diameter of the limiting control wire, such that when the limiting control wire is located at the far end of the insulating protective tube, the cutting head and the limiting control wire form an interference fit in the inner diameter direction of the insulating protective tube.

3. The endoscopic snare cutter according to claim 1, characterized in that, The distal end of the limiting control wire is provided with a stepped portion, the inner diameter of the insulating protective tube is larger than the maximum outer diameter of the cutting head, and the cutting head has an abutment portion; When the limiting control wire moves to the far end of the insulating protective tube, the abutting part of the cutting head abuts against the stepped part of the limiting control wire to limit the axial displacement of the cutting head within the insulating protective tube.

4. The endoscopic snare cutter according to claim 1, characterized in that, The limiting groove extends axially along the proximal handle. The sliding part includes a push block and a slide rod. The push block is disposed on the outside of the proximal handle. The slide rod passes through the limiting groove and is connected to the push block. The proximal end of the limiting control wire is fixed to the distal end of the slide rod. The axial movement of the push block is used to drive the limiting control wire to perform corresponding axial displacement.

5. The endoscopic snare cutter according to claim 1, characterized in that, The tube assembly includes an outer tube and an inner sleeve. The proximal end of the outer tube is fixedly connected to the proximal handle, and the distal end of the outer tube is fixedly connected to the insulating protective tube. The inner sleeve is coaxially sleeved inside the outer tube. The cutting assembly is axially inserted inside the inner sleeve. The limiting control wire is disposed in the gap between the inner sleeve and the outer tube.

6. The endoscopic snare cutter according to claim 5, characterized in that, The tube assembly also includes a guide tube, which is arranged parallel between the inner sleeve and the outer tube. The limiting control wire passes through the guide tube and can move axially along the guide tube.

7. The endoscopic snare cutter according to claim 6, characterized in that, The guide tube has multiple flexible slits spirally distributed along its circumference on its wall to give it bendability.

8. The endoscopic snare cutter according to claim 5, characterized in that, The inner sleeve is provided with an axially extending and through guide channel, and the limiting control wire passes through the guide channel and can move axially along the guide channel.

9. The endoscopic snare cutter according to claim 8, characterized in that, The guide channel is configured as a closed channel located within the inner sleeve wall, or as a groove located within the inner sleeve wall with an opening in the circumferential direction.

10. The endoscopic snare cutter according to claim 5, characterized in that, The inner sleeve includes a spiral flexible wall structure, which makes the inner sleeve flexible.

11. The endoscopic snare cutter according to any one of claims 5-10, characterized in that, The distal end of the limiting control wire is provided with a limiting member. The outer diameter of the limiting member is larger than the gap between the inner sleeve and the outer tube. The limiting member can abut against the proximal end of the inner sleeve to limit the maximum distance the limiting control wire can move to the distal end.

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