Endoscope-used snare incision knife

Abstract

The invention relates to a snare incision knife for an endoscope. The snare incision knife comprises a near-end handle, a tube body assembly, a cutting assembly and a limiting assembly. A limiting sliding groove is formed in the near-end handle. The near end of the tube body assembly is connected with the near-end handle, and the far end of the tube body assembly is provided with an insulating protection tube; the cutting assembly comprises a cutting ring and a cutting head, and the cutting head is arranged at the far end of the cutting ring; the limiting assembly comprises a sliding part and a limiting control wire, the sliding part is slidably arranged in the limiting sliding groove, the near 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; when the limiting control wire moves to the far end of the insulation protection tube, the cutting head and the insulation protection tube abut against each other and are fixed. And when the limiting control wire retreats from the insulation protection tube, the cutting head can continuously move relative to the insulation protection tube.

Description

Technical Field

[0001] The invention relates to the field of medical instruments for interventional surgery, and in particular to a snare cutter for endoscope. Background Art

[0002] Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are important surgical methods for the treatment of early gastrointestinal tumors. Among them, EMR is a treatment method developed on the basis of transurethral resection of polyps and mucosal injection, which can completely remove the diseased tissue and reduce the occurrence of complications such as bleeding and perforation; while ESD can achieve a one-time large-scale resection of larger lesions, provide complete pathological information, and has the advantages of low postoperative recurrence rate.

[0003] With the development of endoscopic interventional technology, endoscopic argon plasma coagulation (APC) has been widely used in the treatment of gastrointestinal polyps due to its advantages such as less trauma, faster speed and good patient tolerance.

[0004] In the above-mentioned surgical procedures, the snare cutter is an important surgical instrument that integrates multiple functions such as cutting, strangulation, and coagulation. However, the existing snare cutter has the problem that the length of the blade extension is difficult to accurately control. Due to the large error when manually adjusting the blade extension length, when the blade extension length is too long, it is easy to cause perforation during surgery, endangering the safety of the patient; and when the blade extension length is too short, it will affect the cutting efficiency and prolong the operation time.

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

[0006] Therefore, how to achieve precise control of the extension length of the blade head to improve surgical safety and operating efficiency has become a technical problem that needs to be urgently solved in this field. Summary of the invention

[0007] The invention discloses an endoscopic snare cutter, aiming to solve the technical problems existing in the prior art.

[0008] In one embodiment, the present invention provides an endoscopic snare cutter, comprising a proximal handle, a tube assembly, a cutting assembly and a limiting assembly;

[0009] A limiting slide groove is provided on the proximal handle;

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

[0011] The cutting assembly includes a cutting ring and a cutting head, wherein the cutting head is arranged at the distal end of the cutting ring;

[0012] The limit assembly includes a sliding part and a limit control wire, the sliding part is slidably arranged in the limit sliding groove, the proximal end of the limit control wire is fixedly connected to the sliding part, and the sliding part is used to drive the limit control wire to move axially;

[0013] When the limit control wire moves to the far end of the insulating protection tube, the cutting head and the insulating protection tube abut against and are fixed to each other; when the limit control wire exits the insulating protection tube, the cutting head can continue to move relative to the insulating protection tube.

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

[0015] As a preferred technical solution, a step portion is provided at the distal end of the limit control wire, the inner diameter of the insulating protection tube is larger than the maximum outer diameter of the cutting head, and the cutting head has an abutment portion;

[0016] When the limit control wire moves to the distal end of the insulating protection tube, the abutment portion of the cutting head abuts against the step portion of the limit control wire to limit the axial displacement of the cutting head in the insulating protection tube.

[0017] As a preferred technical solution, the limiting slide groove extends axially along the proximal handle, and the sliding part includes a pushing block and a sliding rod. The pushing block is arranged on the outside of the proximal handle, the sliding rod is passed through the limiting slide groove and is connected to 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 perform corresponding axial displacement.

[0018] As a preferred technical solution, the tube body assembly includes an outer tube and an inner sleeve, the proximal end of the outer tube is fixedly connected to the proximal handle, the distal end of the outer tube is fixedly connected to the insulating protection tube, the inner sleeve is coaxially sleeved in the outer tube, the cutting assembly is axially inserted in the inner sleeve, and the limit control wire is arranged in the gap between the inner sleeve and the outer tube.

[0019] As a preferred technical solution, the tube body assembly also includes a guide tube, which is arranged parallel to the inner sleeve and the outer tube. The limit control wire is passed through the guide tube and can move axially along the guide tube.

[0020] As a preferred technical solution, a plurality of flexible slits are arranged on the wall of the guide tube and are distributed in a spiral along its circumference, so that the guide tube has bendability.

[0021] As a preferred technical solution, an axially extending and penetrating guide channel is provided in the inner sleeve, and the limit control wire is passed through 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 wall of the inner sleeve, or a groove arranged in the wall of the inner sleeve and having an opening along the circumferential direction.

[0023] As a preferred technical solution, the inner sleeve includes a spiral flexible wall structure, so that the inner sleeve has a bendable property.

[0024] As a preferred technical solution, a limiter is provided at the distal end of the limit control wire, the outer diameter of which is larger than the gap between the inner sleeve and the outer tube, and the limiter can abut against the proximal end of the inner sleeve to limit the maximum distance that the limit control wire moves toward the distal end.

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

[0026] The present invention mainly provides an endoscopic snare cutter. In one embodiment of the present invention, precise control of the position of the cutting head is achieved by setting a matching structure between a limit assembly and a cutting assembly; specifically, when the limit control wire moves to the distal end of the insulating protection tube, the axial limitation of the cutting head relative to the insulating protection tube is achieved through the interference fit or step abutment structure between the cutting head and the limit control wire, which not only avoids the cutting head being retracted too much to affect the electrocoagulation effect, but also prevents the cutting head from being exposed outside the protection tube and causing possible damage to the human body.

[0027] Furthermore, in one embodiment of the present invention, an inner sleeve and a guide structure are provided in the tube body assembly to ensure that the movement trajectory of the limit control wire is stable and reliable. In particular, a limiter can be provided at the distal end of the limit control wire, and the limit control wire is effectively prevented from excessively extending to the distal end by abutting 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, by providing the inner sleeve or the guide tube with a flexible structure, the instrument is endowed with good bending performance to improve the flexibility of surgical operation during intervention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments, which constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions explain the present invention and do not constitute improper limitations on the present invention. In the drawings:

[0029] Figure 1 It is a schematic diagram of the structure of an endoscopic electrosurgical knife in a preferred implementation manner of an embodiment of the present invention;

[0030] Figure 2 It is a schematic diagram of the distal structure of an endoscopic electrosurgical knife in a preferred implementation manner of an embodiment of the present invention;

[0031] Figure 3 It is a schematic diagram of the distal structure of an endoscopic electrosurgical knife in a preferred implementation manner of an embodiment of the present invention;

[0032] Figure 4 A partial enlarged view of a proximal handle in a preferred embodiment of the present invention;

[0033] Figure 5 This is a schematic structural diagram of a sliding part in a preferred implementation manner of an embodiment of the present invention;

[0034] Figure 6 It is a schematic diagram of the distal structure of an endoscopic electrosurgical knife in a preferred implementation manner of an embodiment of the present invention;

[0035] Figure 7 It is a schematic diagram of the distal structure of an endoscopic electrosurgical knife in a preferred implementation manner of an embodiment of the present invention;

[0036] Figure 8 It is a schematic diagram of the distal structure of an endoscopic electrosurgical knife in a preferred implementation manner of an embodiment of the present invention;

[0037] Fig. 9 A cross-sectional view of an inner sleeve in a preferred embodiment of the present invention;

[0038] Fig.10 This is a cross-sectional view of an inner sleeve in another preferred embodiment of the present invention.

[0039] Description of reference numerals:

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

[0041] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. In the description of the present invention, it should be noted that the term "or" is usually used in the sense of including "and / or", unless the content clearly indicates otherwise.

[0042] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or a magnetic connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of this application, the terms "first", "second", etc. 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 invention, those skilled in the art should understand that, unless otherwise clearly specified and limited, the terms "proximal end" and "distal end" are relative to the operator; the "proximal end" is the end of the endoscopic snare cutter that is closer to the user in one-dimensional direction when being operated, and the "distal end" is the end of the endoscopic snare cutter that is farther away from the user in one-dimensional direction when being operated. And those skilled in the art should understand that "far" and "near" do not refer to the three-dimensional space straight-line distance from the user.

[0044] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] In current clinical applications, snare cutters face the problem of difficult to accurately control the position of the cutting head. When the cutting head needs to be retracted into the protective tube, if the retraction position is too deep, the ionization effect of the argon gas will be reduced, affecting the hemostasis effect; if the retraction position is not enough, the cutting head is likely to cause damage to human tissue.

[0046] refer to Figure 1 — Fig.10 In order to solve the problems existing in the prior art, an embodiment of the present invention provides an endoscopic snare cutter, which can be used in endoscopic resection of early-stage tumors and lesions of the digestive tract. Specifically, the endoscopic snare cutter can be inserted into the human body cavity through the working channel of the endoscope to perform a resection operation on the gastrointestinal mucosa and submucosal lesion tissue, and can use high-frequency current to stop bleeding at the resection site, thereby achieving the purpose of minimally invasive treatment.

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

[0048] In a preferred embodiment, the cutting ring 32 is a snare ring, which is made of conductive metal wire, has a certain degree of flexibility, and can form a ring structure when opened; the cutting head 31 is fixedly arranged at the farthest end of the cutting ring 32, and is used to cut the target tissue when powered. In this embodiment, the cutting ring 32 can switch between an open and a closed state: when the cutting ring 32 is fully opened, it is in a ring structure to surround the tissue to be removed; when the cutting ring 32 is contracted, it can grasp and remove the target tissue.

[0049] In this embodiment, the specific structure and size specifications of the cutting head 31 and the cutting ring 32 are no longer specifically limited. Those skilled in the art can freely select appropriate structural forms and size parameters based on actual needs and specific application scenarios while satisfying the cutting and hemostasis functions.

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

[0051] Specifically, the outer tube 21, as the outermost structure of the tube body assembly 20, has sufficient strength and flexibility to ensure the stability of the endoscopic snare cutter during transportation; the inner sleeve 22 is used to provide axial guidance for the cutting assembly 30, and plays a supporting and protective role when the cutting assembly 30 reciprocates.

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

[0053] In some optional embodiments, the inner sleeve 22 can also be made of medical-grade flexible plastic materials, such as polytetrafluoroethylene, polyethylene, polyurethane, etc. These materials themselves have good bending properties, and it is not necessary to set a spiral flexible wall structure; alternatively, the sleeve 22 can also be a tubular structure woven from metal wires or high-strength fibers, which not only maintains the axial thrust transmission capability, but also has good radial flexibility; in addition, the inner sleeve 22 can also be set as other composite structures with bending properties, which will not be described one by one here, and those skilled in the art can select a suitable structural form according to specific application requirements.

[0054] Preferably, the insulating protection tube 23 is fixed to the distal end of the outer tube 21 and is made of insulating material. On the one hand, it can insulate and protect the cutting head 31 to avoid unnecessary contact between the cutting head 31 and surrounding tissues. On the other hand, it can also provide a channel for argon gas to ensure the stability of the ionization process, thereby improving the safety of the operation and the hemostatic effect.

[0055] In a preferred embodiment, the insulating 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 insulating protection tube 23 is larger than the outer diameter of the cutting assembly 30 to ensure that the cutting assembly 30 can move freely therein.

[0056] Preferably, the insulating protection tube 23 can be made of insulating materials such as ceramics and polymer materials. Among them, the polymer insulating material can be selected according to specific needs, such as medical-grade polymer materials such as polytetrafluoroethylene and polyetheretherketone. The specific structural dimensions and materials of the insulating protection tube 23 are not specifically limited in this embodiment. Those skilled in the art can select appropriate structural forms and materials based on actual application requirements while ensuring insulation performance.

[0057] like Figure 2In a preferred embodiment, in order to achieve axial limiting of the cutting head 31, the limiting assembly adopts a combined structure of a sliding part 41 and a limiting control wire 42. Specifically, a limiting slide groove 11 is provided on the proximal handle 10, and the sliding part 41 can slide axially in the limiting slide groove 11. The proximal end of the limiting control wire 42 is fixedly connected to the sliding part 41 and moves synchronously with the movement of the sliding part 41. The limit assembly has two working states: when the operator pushes the sliding part 41 toward the distal end to move the limit control wire 42 to the distal end of the insulating protection tube 23, the cutting head 31, the insulating protection tube 23 and the limit control wire 42 abut and fix each other to achieve axial limitation of the cutting head 31 relative to the insulating protection tube 23. In this state, the length of the cutting head 31 extending outward from the insulating protection tube 23 can be controlled, which can prevent the cutting head 31 from extending too long and causing injury to the patient, and can also prevent the cutting head 31 from extending too short and affecting the cutting efficiency; when the operator pulls the sliding part 41 toward the proximal end to make the limit control wire 42 withdraw from the insulating protection tube 23, the space inside 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, it can continue to move toward the distal end and extend out of the insulating protection tube 23, and finally the cutting ring 32 is fully opened to meet the surgical cutting requirements.

[0058] Preferably, the inner diameter of the insulating protection tube 23 is larger than the maximum outer diameter of the cutting head 31 to ensure that the cutting head 31 can move axially normally 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 smaller than the sum of the maximum outer diameter of the cutting head 31 and the outer diameter of the limit control wire 42, so that when the limit control wire 42 is located at the distal end of the insulating protection tube 23, the limit control wire 42 can occupy a part of the space inside the insulating protection tube 23, and the cutting head 31 and the limit 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 limit control wire 42 due to insufficient lateral space, and thus cannot continue to move distally, so as to effectively prevent the cutting head 31 from excessively extending out of the insulating protection tube 23, thereby avoiding accidental damage to surrounding tissues during surgery.

[0059] like Figure 3 In another preferred embodiment, a step portion 421 is provided at the distal end of the limit control wire 42, and the outer diameter of the step portion 421 is larger than the outer diameter of the main body of the limit control wire 42, and an abutment portion matching the step portion 421 is provided on the cutting head 31; when the limit control wire 42 moves to the distal end of the insulating protection tube 23, the abutment portion of the cutting head 31 will produce axial abutment with the step portion 421 of the limit control wire 42, thereby preventing the cutting head 31 from continuing to move.

[0060] Specifically, the step portion 421 is configured as a block or columnar structure at the distal end of the limit control wire 42, and its outer diameter is larger than the outer diameter of the main body of the limit control wire 42; accordingly, a conical slope that shrinks inward is provided on the distal inner wall of the cutting head 31, and the conical slope constitutes an abutment portion. When the limit control wire 42 moves to the distal end of the insulating protection tube 23, the conical slope of the cutting head 31 cannot pass through the step portion 421, thereby forming an axial limit, thereby preventing the cutting head 31 from continuing to move to the distal end; after the cutting head 31 is used to complete tissue cutting, the cutting head 31 needs to be fully retracted, and then the limit control wire 42 is withdrawn to the proximal end, and the distal space of the insulating protection tube 23 is released. At this time, the cutting head 31 and the cutting ring 32 can be pushed to the distal end again until the cutting ring 32 is fully opened to perform the polyp and other strangulation operations.

[0061] like Figure 4 , Figure 5 In a preferred embodiment, a limited slot 11 is provided on the proximal handle 10 along its axial direction, and the slot passes through the handle wall. The sliding part 41 includes a push block 411 and a slide rod 412. The push block 411 is arranged on the outer surface of the proximal handle 10, so that the operator can directly push and pull with fingers; the slide rod 412 passes through the limited slot 11 and is fixedly connected to the push block 411, so that the movement of the push block 411 can drive the slide rod 412 to slide synchronously in the limited slot 11, and the proximal end of the limited control wire 42 is fixed to the distal end of the slide rod 412, so as to realize the linkage of the push block 411, the slide rod 412 and the limited control wire 42. When the operator pushes or pulls the push block 411, the limited control wire 42 can be driven to move axially accordingly through the transmission effect of the slide 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 limiting control wire 42 , preferably, the length of the limiting sliding groove 11 matches the expected movement distance of the limiting control wire 42 .

[0063] Specifically, the length of the limiting slide groove 11 should meet the travel distance required for the cutting head 31 to move from a fully retracted position to a maximum extended position. This distance is determined by the specific requirements of the surgical operation. It is necessary to ensure that the cutting head 31 can extend a sufficient distance to complete the cutting operation without over-extending to cause safety hazards.

[0064] like Figure 2 In a preferred embodiment, a certain annular gap is formed between the inner sleeve 22 and the outer tube 21, and the limit 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 accordingly, but due to the existence of the gap, the axial movement of the limit control wire 42 therein can still be ensured not to be affected.

[0065] In a preferred embodiment, the limit control wire 42 is made of a biocompatible material, and its material can be nickel-titanium alloy, titanium or stainless steel, etc. Considering the miniaturization requirements of surgical instruments and the need for operational flexibility, the diameter of the limit control wire 42 can be selected in the range of 0.1-0.5 mm.

[0066] like Figure 6 In another preferred embodiment, a guide tube 43 is provided between the inner sleeve 22 and the outer tube 21, the guide tube 43 is parallel to the inner sleeve 22 and the outer tube 21, and the guide tube 43 is elastically fixed to the outer tube 21; a plurality of spiral slits are provided on the tube wall of the guide tube 43, and these slits are evenly distributed in a spiral or twisted shape along the circumferential direction of the guide tube 43, and the spiral angle, slit width and length of each slit can be designed according to the required bending performance, which is not specifically limited here. By providing the spiral slits, the guide tube 43 can obtain good bending deformation ability and can bend in coordination with the turning of the surgical instrument.

[0067] In some optional embodiments, the guide tube 43 can adopt a variety of different tube body structures: the guide tube 43 can be a medical-grade flexible plastic tube, such as made of polytetrafluoroethylene, polyethylene, polyurethane and other materials; it can also be a spring tube wound with stainless steel wire or nickel-titanium alloy wire, and different bending characteristics can be obtained by adjusting the density, wire diameter and material of the coil; it can also be a mesh tube structure woven from multiple metal wires or high-strength polymer fibers; or a multi-layer composite structure can be adopted, such as an inner layer of a braided layer and an outer layer coated with a flexible polymer, which not only ensures mechanical strength but also provides a good smooth surface. The above-mentioned various forms of guide tubes 43 can realize the function of coordinated bending with surgical instruments. Doctors can choose a suitable structural form according to specific usage requirements, and no specific limitation is made in this embodiment.

[0068] Furthermore, the position control wire 42 is inserted into 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 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 a bendable property, when the surgical instrument bends, the guide tube 43 can bend and deform accordingly, thereby ensuring that the position control wire 42 is always in a constrained state, preventing it from getting stuck or deformed at the bending part, and ensuring the movement reliability of the position control wire 42 in various operating postures.

[0069] Preferably, the guide tube 43 can be made of a material with good elasticity such as stainless steel, nickel-titanium alloy, etc., and its inner diameter is larger than the outer diameter of the limit control wire 42, preferably in the range of 0.15-0.6 mm.

[0070] like Figure 8In another preferred embodiment, the inner sleeve 22 adopts an integrated guide structure. Specifically, an axially extending and penetrating guide channel 221 is provided in the inner sleeve 22 to accommodate and guide the movement of the limit control wire 42. Optionally, the guide channel 221 can be configured in two forms:

[0071] In an optional embodiment, the guide channel 221 is configured as a closed channel disposed in the wall of the inner sleeve 22, such as Fig. 9 Specifically, a completely closed elongated channel is opened inside the tube wall of the inner sleeve 22, and the channel extends from the proximal end to the distal end of the inner sleeve 22 to form an independent closed space. The limit control wire 42 is completely wrapped in this closed channel and can move axially therein. This design can protect and guide the limit control wire 42 to the greatest extent and prevent it from interfering with other components;

[0072] In another optional embodiment, the guide channel 221 is configured as a groove disposed in the wall of the inner sleeve 22 and having an opening along the circumferential direction, such as Fig.10 Although the groove is also axially through, one side of the circumferential direction is open. The limit control wire 42 can be inserted into the groove through this opening and move axially in the groove. The limit control wire 42 is more convenient during assembly and maintenance.

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

[0074] In a preferred embodiment, a guide groove extending in the axial direction may be provided on the inner wall of the insulating protection tube 23, and the guide groove is used to guide the limit control wire 42. The limit control wire 42 can slide axially along the guide groove, and the guiding effect of the guide groove can ensure that the movement of the limit control wire 42 is more stable and reliable, and avoid the limit control wire 42 from deflecting or getting stuck during the movement.

[0075] Preferably, the guide groove of the insulating protection tube 23 may also extend to a partial section of the distal end of the outer tube 21 .

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

[0077] In a preferred embodiment, a limiter 44 is provided at the distal end of the limit control wire 42, and the limiter 44 can abut against the proximal end of the inner sleeve 22 to limit the maximum distance that the limit control wire 42 moves toward the distal end, thereby limiting the maximum distance that the limit control wire 42 moves toward the distal end and preventing the limit control wire 42 from excessively moving. The outer diameter of the limiter 44 is larger than the gap between the inner sleeve 22 and the outer tube 21 in the above embodiment, or larger than the inner diameter of the guide tube 43 in the above embodiment, such as Figure 7 , or is larger than the inner diameter of the guide channel 221 in the above-mentioned embodiment, such as Figure 8 , thereby achieving effective positioning of the positioning control wire 42 .

[0078] Preferably, the stopper 44 can be configured as a block structure, such as a cube or a cuboid structure; it can also be configured as a tubular structure, that is, a structure similar to a short tube; it can also be configured as an annular structure, similar to a thickened gasket; or it can be configured as a spherical structure, which is convenient for forming a point contact with the proximal end of the inner sleeve 22. Through these different shapes of the stopper 44 structure design, the moving distance of the limit control wire 42 can be effectively controlled.

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

[0080] During specific use, the endoscopic snare cutter in any of the above-mentioned embodiments is inserted into the patient's body through the working channel of the endoscope, and the diseased part is cut. During the cutting process, the limit control wire 42 cooperates with the insulating protection tube 23 to achieve reliable fixation of the extended length of the cutting head 31, thereby avoiding the risk of patient injury due to the excessively long extended length of the cutting head 31, or affecting the cutting efficiency due to the excessively short extended length of the cutting head 31, and helping to maintain the best cutting effect; further, in the application of argon plasma coagulation (APC), the endoscopic snare cutter provided in the embodiment of the present invention can make the ionization of argon more stable, thereby improving the hemostatic effect.

[0081] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. An endoscopic snare cutter, characterized in that: It includes a proximal handle, a tube body assembly, a cutting assembly and a limiting assembly; The proximal handle is provided with a limiting slide groove; The proximal end of the tube body assembly is connected to the proximal handle, and the distal end of the tube body assembly is provided with an insulating protection tube; The cutting assembly comprises a cutting ring and a cutting head, wherein the cutting head is arranged at the distal end of the cutting ring; The position limiting assembly comprises a sliding part and a position limiting control wire, wherein the sliding part is slidably arranged in the position limiting sliding groove, the proximal end of the position limiting control wire is fixedly connected to the sliding part, and the sliding part is used to drive the position limiting control wire to move axially; When the limit control wire moves to the distal end of the insulating protection tube, the cutting head and the insulating protection tube abut against and are fixed to each other; when the limit control wire exits the insulating protection tube, the cutting head can continue to move relative to the insulating protection tube.

2. The endoscopic snare cutter according to claim 1, characterized in that: The inner diameter of the insulating protection tube is larger than the maximum outer diameter of the cutting head, and smaller than the sum of the maximum outer diameter of the cutting head and the outer diameter of the limit control wire, so that when the limit control wire is located at the distal end of the insulating protection tube, the cutting head and the limit control wire form an interference fit in the inner diameter direction of the insulating protection tube.

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

4. The endoscopic snare cutter according to claim 1, characterized in that: The limiting slide groove extends axially along the proximal handle, and the sliding part includes a pushing block and a sliding rod. The pushing block is arranged on the outer side of the proximal handle, and the sliding rod is passed through the limiting slide groove and connected to 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 perform corresponding axial displacement.

5. The endoscopic snare cutter according to claim 1, characterized in that: The tube body assembly includes an outer tube and an inner sleeve, the proximal end of the outer tube is fixedly connected to the proximal handle, the distal end of the outer tube is fixedly connected to the insulating protection tube, the inner sleeve is coaxially sleeved in the outer tube, the cutting assembly is axially inserted in the inner sleeve, and the limit control wire is arranged 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 body assembly also includes a guide tube, which is arranged in parallel between the inner sleeve and the outer tube. The limit control wire is passed 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 tube wall of the guide tube is provided with a plurality of flexible slits distributed in a spiral along the circumference thereof, so that the guide tube has a bendable property.

8. The endoscopic snare cutter according to claim 5, characterized in that: The inner sleeve is provided with an axially extending and penetrating guide channel, the limit control wire is passed 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 arranged in the wall of the inner sleeve, or a groove arranged in the wall of the inner sleeve and having an opening along the circumferential direction.

10. The endoscopic snare cutter according to claim 5, characterized in that: The inner sleeve comprises a spiral flexible wall structure, so that the inner sleeve has bendable properties.

11. The endoscopic snare cutter according to any one of claims 5 to 10, characterized in that: A limit piece is provided at the distal end of the limit control wire, the outer diameter of which is larger than the gap between the inner sleeve and the outer tube, and the limit piece can abut against the proximal end of the inner sleeve to limit the maximum distance that the limit control wire moves toward the distal end.

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