Snare

Abstract

Provided in the embodiments of the present description is a snare, comprising: a snaring portion, which comprises a first rigid portion and a second rigid portion, wherein the first rigid portion is connected to the second rigid portion, at least part of the structure of the second rigid portion is located at a distal end compared to the first rigid portion, and the rigidity of the first rigid portion is less than the rigidity of the second rigid portion; a connecting portion, which can accommodate at least part of the snaring portion; and an operating portion, which is connected to the snaring portion, and drives part or all of the snaring portion to extend out of or enter the connecting portion.

Description

A snare

[0001] Priority Statement

[0002] This application claims priority to Chinese application No. 202311219288.7 filed on September 20, 2023 and Chinese application No. 202311346415.X filed on October 17, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to the field of medical devices, and in particular to a snare. Background Art

[0004] Snares are a commonly used medical device in contemporary medicine. They can resect lesions by contracting the snare. However, during the tissue removal process, the axial movement of the snare is smaller than the radial movement when it is inserted into the sheath. This causes the originally annular snare to gradually become an elongated snare, preventing the tissue from being completely enclosed by the elongated snare. Consequently, the snare is unable to gradually tighten and secure the tissue, compromising the completeness of lesion resection.

[0005] Therefore, it is hoped to propose a snare that can stabilize the shape change of the snare when it is inserted into the sheath, avoid the formation of a slender snare, facilitate the collection and fixation of the lesion, and thus ensure the complete resection of the lesion; it can also avoid the easy slippage between the snare and the lesion, making the contact between the two closer and more stable.

[0006] Summary of the Invention

[0007] One or more embodiments of the present specification provide a snare, comprising: a snare portion, the snare portion comprising a first rigid portion and a second rigid portion, the first rigid portion being connected to the second rigid portion, wherein at least a portion of the structure of the second rigid portion is located distally relative to the first rigid portion, and the rigidity of the first rigid portion is less than that of the second rigid portion; a connecting portion capable of accommodating at least a portion of the snare portion; and an operating portion connected to the snare portion, the operating portion driving a portion or all of the snare portion to extend out of or enter the connecting portion.

[0008] In some embodiments, when the snare portion has not entered or has partially entered the connecting portion, the diameter-to-length ratio of the snare portion ranges from 0.5 to 1, wherein the diameter-to-length ratio is the ratio of the size of the snare portion in the snare portion along the radial direction of the snare to the size of the snare portion along the axial direction of the snare.

[0009] In some embodiments, during the process of the snare portion partially entering the connecting portion, a first change rate of the snare portion in the snare portion is not greater than a second change rate, wherein the first change rate represents a ratio of a change in a radial dimension of the snare portion to an initial radial dimension, and the second change rate represents a ratio of a change in an axial dimension of the snare portion to an initial axial dimension.

[0010] In some embodiments, the first rigid portion includes a first connecting segment, the second rigid portion includes a second connecting segment, the second connecting segment is located distally compared to the first connecting segment, and the stiffness of the first connecting segment is less than that of the second connecting segment.

[0011] In some embodiments, the two ports at the distal end of the first connecting segment are respectively connected to the two ports at the proximal end of the second connecting segment, and the two ports at the proximal end of the first connecting segment are connected to the operating portion.

[0012] In some embodiments, when the snare portion does not enter the connecting portion, a ratio of a dimension of the second connecting segment along the axial direction of the snare to a dimension of the snare portion along the axial direction of the snare is in a range of 0.1 to 0.35.

[0013] In some embodiments, a ratio of the stiffness of the first connecting segment to the stiffness of the second connecting segment ranges from 0.2 to 0.9.

[0014] In some embodiments, both the first connecting segment and the second connecting segment include an arc-shaped structure, wherein a curvature of the arc-shaped structure of the first connecting segment is smaller than a curvature of the arc-shaped structure of the second connecting segment.

[0015] In some embodiments, a ratio of a curvature of the arc-shaped structure of the first connecting segment to a curvature of the arc-shaped structure of the second connecting segment ranges from 0.1 to 0.85.

[0016] In some embodiments, the hardness of the second connecting segment is greater than the hardness of the first connecting segment.

[0017] In some embodiments, the first characteristic dimension is smaller than the second characteristic dimension, wherein the first characteristic dimension is the characteristic dimension of the cross section of the first connecting segment perpendicular to the axial direction of the first connecting segment, and the second characteristic dimension is the characteristic dimension of the cross section of the second connecting segment perpendicular to the axial direction of the second connecting segment.

[0018] In some embodiments, the ratio of the first characteristic size to the second characteristic size ranges from 0.5 to 0.95.

[0019] In some embodiments, the first connecting segment is composed of at least two first connecting units, the second connecting segment is composed of at least one second connecting unit, and the first number of strands is greater than the second number of strands, wherein the first number of strands is the number of strands of the first connecting units constituting the first connecting segment, and the second number of strands is the number of strands of the second connecting units constituting the second connecting segment.

[0020] In some embodiments, when the absolute value of the difference between the first characteristic dimension and the second characteristic dimension is less than or equal to a first preset difference threshold, the first number of strands is greater than the second number of strands; wherein the first characteristic dimension is the characteristic dimension of the cross-section of the first connecting segment perpendicular to the axial direction of the first connecting segment, and the second characteristic dimension is the characteristic dimension of the cross-section of the second connecting segment perpendicular to the axial direction of the second connecting segment.

[0021] In some embodiments, the first preset threshold is any value between 0 and 0.1 mm.

[0022] In some embodiments, the second cross-section is set to one or more of a circle, a square, and a hexagon, and the first cross-section is set to one or more of a semicircle, a triangle, and a rectangle, wherein the first cross-section is a cross-section of the first connecting segment perpendicular to the axial direction of the first connecting segment, and the second cross-section is a cross-section of the second connecting segment perpendicular to the axial direction of the second connecting segment.

[0023] In some embodiments, the second connecting segment includes a base connecting segment and a stiffness reinforcement member, and the stiffness reinforcement member is fixed to the base connecting segment.

[0024] In some embodiments, the first connecting segment and the base connecting segment are an integral structure.

[0025] In some embodiments, the second rigid portion further includes a third connecting segment, which is located at the proximal end compared to the first connecting segment, the stiffness of the first connecting segment is smaller than the stiffness of the second connecting segment, and the stiffness of the first connecting segment is smaller than the stiffness of the third connecting segment.

[0026] In some embodiments, the two ports at the distal end of the first connecting segment are respectively connected to the two ports at the proximal end of the second connecting segment, the two ports at the proximal end of the first connecting segment are respectively connected to the two ports at the distal end of the third connecting segment, and the two ports at the proximal end of the third connecting segment are connected to the operating part.

[0027] In some embodiments, when the snare portion does not enter the connecting portion, a ratio of a size of the third connecting segment along the axial direction of the snare to a size of the snare portion along the axial direction of the snare is in a range of 1 / 10 to 2 / 5.

[0028] In some embodiments, the stiffness of the third connecting segment is the same as the stiffness of the second connecting segment; or the stiffness of the third connecting segment is greater than the stiffness of the second connecting segment; or the stiffness of the third connecting segment is less than the stiffness of the second connecting segment.

[0029] In some embodiments, when the stiffness of the third connecting segment is the same as the stiffness of the second connecting segment, the ratio of the stiffness of the first connecting segment to the stiffness of the second connecting segment is in the range of 0.2 to 0.9; or when the stiffness of the third connecting segment is greater than the stiffness of the second connecting segment, the ratio of the stiffness of the second connecting segment, the stiffness of the first connecting segment and the stiffness of the third connecting segment is in the range of (1.1 to 3.4):1:(1.4 to 3.6); or when the stiffness of the third connecting segment is less than the stiffness of the second connecting segment, the ratio of the stiffness of the second connecting segment, the stiffness of the first connecting segment and the stiffness of the third connecting segment is in the range of (1.1 to 3.5):1:(1 to 3.2).

[0030] In some embodiments, the hardness of the third connecting segment is greater than the hardness of the first connecting segment.

[0031] In some embodiments, the first characteristic dimension is smaller than the third characteristic dimension, wherein the first characteristic dimension is the characteristic dimension of the cross section of the first connecting segment perpendicular to the axial direction of the first connecting segment, and the third characteristic dimension is the characteristic dimension of the cross section of the third connecting segment perpendicular to the axial direction of the third connecting segment.

[0032] In some embodiments, a ratio of the first characteristic size to the third characteristic size ranges from 0.5 to 0.95.

[0033] In some embodiments, the first connecting segment is composed of at least two first connecting units, the third connecting segment is composed of at least one third connecting unit, and the first number of strands is greater than the third number of strands, wherein the first number of strands is the number of strands of the first connecting units constituting the first connecting segment, and the third number of strands is the number of strands of the third connecting units constituting the third connecting segment.

[0034] In some embodiments, when the difference between the first characteristic dimension and the third characteristic dimension is less than or equal to a second preset difference threshold, the first number of strands is greater than the third number of strands, wherein the first characteristic dimension is the characteristic dimension of the cross-section of the first connecting segment perpendicular to the axial direction of the first connecting segment, and the third characteristic dimension is the characteristic dimension of the cross-section of the third connecting segment perpendicular to the axial direction of the third connecting segment.

[0035] In some embodiments, the second preset threshold is any value between 0 and 0.1 mm.

[0036] In some embodiments, the third cross-section is set to one or more of a circle, a square, and a hexagon, and the first cross-section is set to one or more of a semicircle, a triangle, and a rectangle, wherein the first cross-section is a cross-section of the first connecting segment perpendicular to the axial direction of the first connecting segment, and the third cross-section is a cross-section of the third connecting segment perpendicular to the axial direction of the third connecting segment.

[0037] In some embodiments, the third connecting segment includes a basic connecting segment and a stiffness reinforcement member, and the stiffness reinforcement member is fixed to the basic connecting segment.

[0038] In some embodiments, the snare portion is a symmetrical structure with the snare axial axis as the symmetry axis, and / or the second rigid portion is a symmetrical structure with the snare axial axis as the symmetry axis.

[0039] In some embodiments, the connecting portion includes a first traction member and a sheath, the first traction member is disposed in the sheath, and the first traction member connects the snare portion and the operating portion; the operating portion drives part or all of the snare portion to extend out of or enter the sheath through the first traction member.

[0040] In some embodiments, at least a portion of the first rigid portion and the second rigid portion that is closer to the first traction member is an integral structure with the first traction member; and / or at least a portion of the first rigid portion and the second rigid portion that is closer to the first traction member is fixedly connected to the first traction member.

[0041] In some embodiments, the snare portion includes a base portion and an adjustment portion, the adjustment portion is slidably connected to the base portion, the two ports at the proximal end of the base portion are connected to the distal end of the first traction member, the adjustment portion includes the first rigid portion and the second rigid portion, and the operating portion drives part or all of the base portion and part or all of the adjustment portion to extend out of or enter the sheath.

[0042] In some embodiments, the connecting portion further includes a second traction member, which is disposed in the sheath, and the second traction member and the first traction member are both configured to be able to move axially along the sheath, and the second traction member can slide relative to the first traction member; the second traction member includes a first traction rope and a second traction rope, the port at the distal end of the first traction rope is connected to a port at the proximal end of the adjustment portion, and the port at the distal end of the second traction rope is connected to another port at the proximal end of the adjustment portion, and the first traction rope and the second traction rope slide along the axial direction of the sheath, driving the adjustment portion to slide relative to the base portion.

[0043] In some embodiments, the operating portion includes an adjusting member connected to two ports at the proximal end of the snare portion through the first traction member, and the adjusting member drives the two ports at the proximal end of the snare portion to move synchronously or asynchronously.

[0044] In some embodiments, the first rigid portion and / or the second rigid portion are configured with markings. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] This specification will be further described in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, like numbers represent like structures, wherein:

[0046] FIG1 is an exemplary module diagram of a snare according to some embodiments of the present specification;

[0047] FIG2 is a schematic diagram of a snare according to some embodiments of the present specification;

[0048] FIG3 is a schematic diagram of a snare portion according to some embodiments of the present specification;

[0049] FIG4 is a schematic diagram of another snare according to some embodiments of the present specification;

[0050] FIG5 is a schematic diagram of another snare portion according to some embodiments of the present specification;

[0051] FIG6A is a schematic diagram of a snare in use;

[0052] FIG6B is a schematic diagram of a snare in use according to some embodiments of the present specification;

[0053] FIG7 is a schematic diagram showing changes in the snare portion during operation according to some embodiments of this specification;

[0054] FIG8A is a schematic diagram of an elliptical snare portion according to some embodiments of the present specification;

[0055] FIG8B is a schematic diagram of a circular snare portion according to some embodiments of the present specification;

[0056] FIG8C is a schematic diagram of a heart-shaped snare portion according to some embodiments of the present specification;

[0057] FIG8D is a schematic diagram of a hexagonal snare portion according to some embodiments of the present specification;

[0058] FIG8E is a schematic diagram of a shield-shaped snare portion according to some embodiments of the present specification;

[0059] FIG8F is a schematic diagram of a polygonal snare portion according to some embodiments of the present specification;

[0060] FIG9 is a schematic diagram of a first connecting unit in a first connecting section according to some embodiments of this specification;

[0061] FIG10 is a schematic diagram of another snare portion according to some embodiments of the present specification;

[0062] FIG11 is a schematic diagram of another snare portion according to some embodiments of the present specification;

[0063] FIG12A is an enlarged schematic diagram of a portion of a snare portion according to some embodiments of the present specification;

[0064] FIG12B is another enlarged schematic diagram of a portion of a snare portion according to some embodiments of the present specification;

[0065] FIG13 is another enlarged cross-sectional view of a portion of a snare portion according to some embodiments of this specification;

[0066] FIG14 is a schematic diagram of a partial structure of a first traction member and a second traction member according to some embodiments of this specification;

[0067] FIG15 is a schematic diagram of a portion of an operating unit according to some embodiments of this specification;

[0068] FIG16 is a schematic diagram of a method for testing material stiffness according to some embodiments of the present specification.

[0069] Reference numerals: 100, snare; 110, operating portion; 111, handle; 112, first sliding member; 113, second sliding member; 120, connecting portion; 121, sheath; 1211, outer sheath; 1212, inner sheath; 122, first traction member; 123, connecting tube; 124, supporting protective tube; 125, connecting member; 126, second traction member; 126-1, first traction rope; 126-2, second traction rope; 127, limiting ring; 130, snare portion; 131, First connecting section; 131-1, sub-connecting section; 131-a, first connecting unit; 132, second connecting section; 132-1, basic connecting section; 132-2, stiffness reinforcement; 133, third connecting section; 134, guide structure; 135, connecting ring; 136, first adjustment channel; 137, second adjustment channel; 1301, base part; 1302, adjustment part; 200, lesion; 310, material; 320, deformed material; 330, support member; 340, force-applying member. DETAILED DESCRIPTION

[0070] To more clearly illustrate the technical solutions of the embodiments of this specification, the following briefly describes the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this specification. Those skilled in the art can apply this specification to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0071] It should be understood that the terms "system," "device," "unit," and / or "module" used herein are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels. However, if other terms can achieve the same purpose, the terms may be replaced by other expressions.

[0072] As used in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not refer to the singular but also include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0073] Flowcharts are used throughout this specification to illustrate the operations performed by systems according to embodiments of this specification. It should be understood that preceding or following operations do not necessarily need to be performed in exact order. Instead, the steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0074] In some snare designs, the snare portion becomes increasingly elongated as the snare tightens during operation. The snare portion is the portion of the snare that lies outside the connecting portion (e.g., the sheath within the connecting portion). For example, the dimensional changes of the snare portion are shown in the table below.

[0075] The initial stage to the third stage is the process of gradual tightening of the snare. The aforementioned axial dimension is the maximum dimension of the snare portion along the axial direction A of the snare 100 as shown in Figures 2 and 4 , and the aforementioned radial dimension is the maximum dimension of the snare portion along the radial direction B of the snare 100 as shown in Figures 2 and 4 . For example, when the snare portion is an elliptical snare as shown in Figure 2 , the axial dimension of the snare portion is the dimension corresponding to the major axis along the axial direction A, and the radial dimension is the dimension corresponding to the minor axis along the radial direction B.

[0076] As can be seen from the table above, the diameter-to-length ratio of the snare portion decreases as it is inserted into the sheath, causing it to become increasingly elongated, preventing the lesion from being completely enclosed by the elongated snare. Some embodiments of the present disclosure utilize a snare portion comprised of multiple sections with varying rigidity, namely a first rigid section and a second rigid section. The first rigid section is connected to the second rigid section, at least a portion of the second rigid section is located distally relative to the first rigid section, and the first rigid section has a lower rigidity than the second rigid section. The varying rigidity of each rigid section allows for different deformation during snare operation, thereby ensuring stable morphological changes in the snare portion, preventing the snare portion from becoming increasingly elongated, ensuring the integrity of the snare portion's encapsulation of the lesion, and improving both efficiency and completeness of the cut. This also prevents slippage between the snare portion and the lesion, ensuring a more secure and stable contact between the two.

[0077] It is worth noting that the stiffness of each rigid part described in this specification can be determined by a variety of methods. For example, tensile test method, compression test method, bending test method, torsion test method, etc. For another example, the stiffness of each rigid part can also be determined by testing using the method shown in Figure 16. As shown in Figure 16, a certain material 310 can be placed on a support member 330, and a force-applying member 340 can apply a vertical downward force F toward the center position of the material 310. The material 310 is deformed under the action of the force F to obtain a deformed material 320, wherein the deformation magnitude of the material 310 and the deformed material 320 along the direction of the force F is a displacement H, and the stiffness K of the aforementioned material 310 can be calculated by the formula K=F / H. In addition, the hardness described in this specification can also be determined by a variety of methods, such as the Rockwell hardness test method, the Vickers hardness test method, the Brinell hardness test method, etc.

[0078] FIG. 1 is an exemplary module diagram of a snare according to some embodiments of the present specification.

[0079] The snare 100 can be used to remove lesions (eg, polyps). As shown in FIG1 , the snare 100 can include an operating portion 110 , a connecting portion 120 , and a snare portion 130 .

[0080] The operating portion 110 can be used by an operator (e.g., a doctor or nurse using the snare 100) to manipulate the snare 100. The operating portion 110 can be connected to the snare portion 130 and can cause the snare portion 130 to partially or completely extend or retract into the connecting portion 120. The operating portion 110 can include a handle 111 and an adjustment member. The handle 111 can be grasped by the operator, and the adjustment member can be used to control the snare 100. The adjustment member can include a first adjustment member that can control the snare portion 130 to partially or completely extend or retract into the connecting portion 120. For example, the first adjustment member can include a first slider 112 as shown in FIG. 2 , which can slide relative to the handle 111. When using the snare 100, the operator can insert a finger into the retaining hole of the first slider 112 and apply a force along the axial direction A of the snare 100 to the first slider 112, causing the first slider 112 to slide along the axial direction A relative to the handle 111. For another example, the first adjusting member may further include a second sliding member 113 as shown in FIG15 . The second sliding member 113 may also slide relative to the handle 111 . The sliding of the second sliding member 113 may drive the sheath 121 to slide along the axial direction A of the snare 100 . For more information about the first sliding member 112 and the second sliding member 113 , please refer to the relevant description later in this specification.

[0081] The connecting portion 120 can accommodate at least a portion of the snare portion 130. The connecting portion 120 is also used to connect the operating portion 110 and the snare portion 130. As shown in FIG2 , the connecting portion 120 can include a sheath 121 and a first pulling member 122. The first pulling member 122 is disposed within the sheath 121 and connects the snare portion 130 to the operating portion 110. The operating portion 110 drives the snare portion 130 partially or completely out of or into the sheath 121 through the first pulling member 122. For example, the proximal end of the first pulling member 122 can be connected to the first sliding member 112, and the distal end of the first pulling member 122 can be connected to the snare portion 130. Sliding the first sliding member 112 can drive the first pulling member 122 to move along the axial direction A, thereby causing the snare portion 130 to partially or completely extend out of or enter the sheath 121. For more information about the first pulling member 122, please refer to the relevant description later in this specification.

[0082] It is worth noting that, as shown in FIG. 2 , the distal end in this specification refers to an end farther from the operating portion 110 of the snare 100 , and the proximal end refers to an end closer to the operating portion 110 of the snare 100 .

[0083] In some embodiments, the connection portion 120 may further include other structures. As shown in FIG2 , the connection portion 120 may further include a connecting tube 123, the proximal end of which is connected to the distal end of the first pulling member 122, and the distal end of which is connected to the snare portion 130. The connecting tube 123 may be disposed within or outside the sheath 121. The connection portion 120 may further include a supporting protective tube 124. The supporting protective tube 124 may be disposed outside the sheath 121. It is understood that when the sheath 121 is made of a flexible material, the supporting protective tube 124 can support the sheath 121 to ensure normal use of the snare 100. The connection portion 120 may further include a connecting member 125, through which the sheath 121 can be connected to the operating portion 110.

[0084] The snare portion 130 can be used to excise a designated area of ​​a patient. The snare portion 130 can be an annular structure. For example, the snare portion 130 can be shaped like a circular annular structure, an elliptical annular structure, a heart-shaped annular structure, a shield-shaped annular structure, a hexagonal annular structure, or other polygonal annular structures. The snare portion 130 can include one or more straight segment structures. For example, the hexagonal snare portion 130 shown in FIG8D can be composed of multiple straight segment structures. The snare portion 130 can also include one or more arc-shaped structures. For example, the heart-shaped snare portion 130 shown in FIG8C can be composed of multiple arc-shaped structures. As another example, the shield-shaped snare portion 130 shown in FIG8E can be composed of multiple arc-shaped structures and multiple straight segment structures. For more information on arc-shaped structures, please refer to the following text of this specification.

[0085] In some embodiments, the snare portion 130 may include a first rigid portion and a second rigid portion, wherein the first rigid portion is connected to the second rigid portion, wherein at least a portion of the second rigid portion is located distally relative to the first rigid portion, and the first rigid portion has a lower rigidity than the second rigid portion. In some embodiments, the first rigid portion may include a first connecting segment 131, and the second rigid portion may include a second connecting segment 132. In some embodiments, the second rigid portion may further include a third connecting segment 133. For more information about the first connecting segment 131, the second connecting segment 132, and the third connecting segment 133, please refer to the following text.

[0086] The snare portion 130 can be formed from a variety of biocompatible materials. For example, the material of the snare portion 130 may include, but is not limited to, metals, polymers, alloys, and the like. Furthermore, the material of the snare portion 130 may include steel, tungsten, nitinol 6, or titanium. The material of the snare portion 130 may refer to the material of the first connecting segment 131 and / or the second connecting segment 132 in the embodiment of FIG. 2 , or the material of the first connecting segment 131, the second connecting segment 132, and / or the third connecting segment 133 in the embodiment of FIG. 4 .

[0087] Some embodiments of the present specification increase the rigidity of the distal end of the snare portion 130 by configuring the snare portion 130 to include a first rigid portion and a second rigid portion with different rigidities, thereby preventing the snare portion 130 from becoming elongated during operation and ensuring that the snare portion 130 fits snare-removed closely to the lesion.

[0088] In some embodiments, the first rigid portion and / or the second rigid portion are provided with markings to facilitate an operator to more intuitively understand the difference in rigidity of the snare portion and to adjust the snare portion as needed. For example, the first rigid portion and the second rigid portion may be provided with different colors and / or reflectivity.

[0089] In some embodiments, when the second rigid portion includes only the second connecting segment 132 and the snare portion 130 does not extend into the connecting portion 120, the ratio of the dimension of the second connecting segment 132 along the axial direction A of the snare 100 to the dimension of the snare portion 130 along the axial direction A of the snare 100 is in the range of 0.1 to 0.35, preferably in the range of 0.125 to 0.25. It is worth noting that, as shown in FIG3 , the dimension of the second connecting segment 132 along the axial direction A of the snare 100 is b, and the dimension of the snare 100 along the axial direction A is L. On the one hand, when the ratio of b to L is less than 0.1, even if the second connecting segment 132 with greater rigidity is provided, its dimension along the axial direction A of the snare 100 is too small. Therefore, when the snare 100 is in operation, the overall deformation of the snare portion 130 is minimal, and the snare portion 130 will still become slender. On the other hand, when the ratio of b to L is greater than 0.35, the dimension of the second connecting segment 132 with greater rigidity along the axial direction A of the snare 100 is too large, which may prevent the snare portion 130 from properly adhering to and securing the lesion. After the first connecting segment 131 enters the sheath 121, the snare portion 130 will still become slender during subsequent use because the snare portion only includes the second connecting segment 132. Preferably, when the ratio of b to L is one-sixth, the snare portion 130 changes most stably and can properly adhere to the lesion.

[0090] In some embodiments, when the second rigid portion further includes a third connecting segment 133 and the snare portion 130 has not yet entered the connecting portion 120, the ratio of the dimension of the third connecting segment 133 along the axial direction A of the snare 100 to the dimension of the snare portion 130 along the axial direction A of the snare 100 ranges from 1 / 10 to 2 / 5, preferably from 1 / 5 to 1 / 3. As shown in FIG5 , the dimension of the third connecting segment 133 along the axial direction A of the snare 100 is c, and the dimension of the snare 100 along the axial direction A is L. On the one hand, when the ratio of c to L is less than 1 / 10, the snare is insufficiently rigid and poorly adheres to the wall. On the other hand, when the ratio of c to L is greater than 2 / 5, the snare portion 130 becomes elongated due to a relatively small diameter during contraction.

[0091] Preferably, when the ratio of b, a and c is 1:2:1, the snare portion 130 changes most stably and can fit well with the lesion.

[0092] By limiting the dimensions of the first rigid portion and the second rigid portion along the axial direction A of the snare 100 , the stability of the snare 100 during use can be maintained, preventing the snare portion 130 from becoming elongated during operation, and ensuring that the lesion is snatched away in a close fit.

[0093] In some embodiments, the snare portion 130 is a symmetrical structure with the axial axis of the snare 100 as the axis of symmetry. For example, the snare portion 130 may be an elliptical snare portion 130 as shown in FIG8A , a circular snare portion 130 as shown in FIG8B , a heart-shaped snare portion 130 as shown in FIG8C , a hexagonal snare portion 130 as shown in FIG8D , a shield-shaped snare portion 130 as shown in FIG8E , or a polygonal snare portion 130 as shown in FIG8F . The snare portions 130 of various shapes can be adapted for different applications. For example, the elliptical snare portion 130 shown in FIG8A can be used to snare common lesions (e.g., typical polyps). The circular snare portion 130 shown in FIG8B has a larger radial dimension (radial direction B as shown in FIG2 ), making it easier to access the lesion and suitable for grasping larger, flat lesions. For another example, the hexagonal snare portion 130 shown in FIG8D can be used to snare flat lesions. By configuring the snare portion 130 to be a symmetrical structure, the snare portion 130 is deformed stably during use, and the lesion can be wrapped more completely. In some embodiments, the second rigid portion is a symmetrical structure with the axial axis of the snare 100 as the symmetry axis.

[0094] In some embodiments, the snare portion 130 may also have other shapes. For example, the snare portion 130 may also be crescent-shaped, which facilitates adjustment of its radial width (radial direction B as shown in FIG2 ). In addition, the snare portion 130 may also be used in conjunction with a transparent cap.

[0095] In some embodiments, the snare portion 130 may further include other structures. For example, the snare portion 130 may further include a guide structure 134. This guide structure 134, which is V-shaped and can be used to guide and locate the lesion, may be positioned at the forward end of the snare 100 along the axial direction A. As shown in FIG1 , the guide structure 134 may be positioned distally to the second connecting segment 132.

[0096] In some embodiments, when the snare portion 130 is not within the connection portion 120 or is partially within the connection portion 120, the diameter-to-length ratio of the snare portion 130 may be in the range of 0.4 to 1.1. The diameter-to-length ratio is the ratio of the snare portion of the snare portion 130 along the radial direction of the snare 100 to the snare portion along the axial direction A of the snare 100. It should be understood that the snare portion is the portion of the snare portion 130 located outside the connection portion 120 (e.g., the sheath 121 within the connection portion 120). When the snare portion 130 is not within the connection portion 120, the snare portion may be the entire snare portion 130. As shown in FIG. 3 , when the snare portion 130 is not within the connection portion 120, the diameter-to-length ratio is D / L, where D is the snare portion along the radial direction of the snare 100 and L is the snare portion along the axial direction A of the snare 100. Preferably, when the snare portion 130 is partially inserted into the connecting portion 120 or not, the diameter-to-length ratio of the snare portion 130 is in the range of 0.5 to 1. If the diameter-to-length ratio of the snare portion 130 is too large or too small, the snare portion 130 may become elongated in the radial or axial directions. For example, when the diameter-to-length ratio of the snare portion 130 is 0.2, the snare portion 130 L is excessively greater than the snare portion D, resulting in the snare portion 130 becoming elongated in the axial direction.

[0097] The diameter-to-length ratio ranges of the snare portion 130 of different shapes can vary. For example, when the snare portion 130 is elliptical, the diameter-to-length ratio of the snare portion 130 can be 0.5. For another example, when the snare portion 130 is circular, the diameter-to-length ratio of the snare portion 130 can be 1. By setting different diameter-to-length ratio ranges for snare portions 130 of different shapes, the snare portion 130 can maintain stability in axial and radial directions during operation, preventing it from becoming too slender and potentially affecting its usability.

[0098] As shown in FIG7 , during the contraction of a certain snare portion 130, the snare portion located outside the connecting portion 120 may change from snare portion 130-a to snare portion 130-b and then to snare portion 130-c. L1, L2, and L3 are respectively the dimensions of the snare portions 130-a, 130-b, and 130-c along the axial direction A, and D1, D2, and D3 are respectively the dimensions of the snare portions 130-a, 130-b, and 130-c along the radial direction B. During the contraction of the snare portion 130, D1 / L1, D2 / L2, and D3 / L3 are always no less than 0.5 and no greater than 1. Preferably, the aforementioned ratios may be 0.7. In some embodiments of this specification, the above-mentioned arrangement can prevent the snare portion 130 from gradually becoming slender due to an excessive size in the axial direction A, or gradually becoming flat due to an excessive size in the radial direction B, during operation, thereby ensuring the stability of the snare portion 130 changes.

[0099] In some embodiments, when the snare portion 130 partially enters the connecting portion 120, the first rate of change of the snare portion in the snare portion 130 is no greater than the second rate of change. The first rate of change represents the ratio of the change in the size of the snare portion along the radial direction B of the snare 100 to the initial radial dimension, and the second rate of change represents the ratio of the change in the size of the snare portion along the axial direction A of the snare 100 to the initial axial dimension. The aforementioned initial radial dimension and initial axial dimension are the initial values ​​of the size of the snare portion 130 along the radial direction B and the axial direction A, respectively, when the snare portion 130 has not entered the connecting portion 120. In some embodiments, at any time when the snare 100 is in operation, the following formula (1) is satisfied:

[0100] Wherein, D is the initial radial dimension of the snare portion 130, L is the initial axial dimension of the snare portion 130, and D i is the size of the snare portion along the radial direction B of the snare 100 at the current moment, L i is the size of the snare portion along the snare axial direction A at the current moment.

[0101] Some embodiments of this specification limit the magnitude relationship between the first change rate and the second change rate so that the radial change of the snare portion 130 is smaller than the axial change, thereby preventing the snare portion 130 from becoming gradually slender, which is beneficial for the collection and fixation of the lesion.

[0102] In some embodiments, the first rigid portion may include a first connecting segment 131, and the second rigid portion may include a second connecting segment 132. Fig. 2 is a schematic diagram of a snare according to the aforementioned embodiment of this specification.

[0103] As shown in Figures 2 and 3, the snare portion 130 may include a first connecting segment 131 and a second connecting segment 132, with the second connecting segment 132 being located distally relative to the first connecting segment 131. The second connecting segment 132 and the first connecting segment 131 may have a symmetrical structure with the axial axis of the snare 100 as the axis of symmetry, or an asymmetrical structure. For example, the second connecting segment 132 and the first connecting segment 131 shown in Figure 2 may both have a symmetrical structure with the axial axis of the snare 100 as the axis of symmetry, in which case the second connecting segment 132 is located distally relative to the first connecting segment 131. For another example, the second connecting segment 132 and / or the first connecting segment 131 may be an asymmetric structure with the axial axis of the snare 100 as the symmetry axis. For example, the second connecting segments 132 on both sides of the axis of the snare 100 are of different lengths in the axial direction A, and / or the first connecting segments 131 on both sides of the axis of the snare 100 are of different lengths in the axial direction A. In this case, the distal end of the second connecting segment 132 is located distally (i.e., farther away from the operating portion 110) than the distal end of the first connecting segment 131.

[0104] In some embodiments, the two ports at the distal end of the first connecting segment 131 can be connected to the two ports at the proximal end of the second connecting segment 132, respectively, to form the snare portion 130. The two ports at the proximal end of the first connecting segment 131 are connected to the operating portion 110. The first connecting segment 131 and the second connecting segment 132 can be strip-shaped structures. In some embodiments, the first connecting segment 131 can be a strip-shaped structure, and any position of the strip structure except the ports can be connected to the first traction member 122. The connection point of the aforementioned connection can be the proximal end of the first connecting segment 131. The two ports of the strip structure can be the distal end of the first connecting segment 131 and connected to the two ports at the proximal end of the second connecting segment 132. The proximal end of the first traction member 122 can be connected to the operating portion 110 (for example, the first sliding member 112 in the operating portion 110). In some embodiments, the first connecting segment 131 can also be composed of two strip structures. As shown in Figure 2, the first connecting segment 131 can include two sub-connecting segments 131-1. The two ports at the distal ends of the two sub-connection segments 131-1 are connected to the two ports at the proximal end of the second connection segment 132. The two ports at the proximal ends of the two sub-connection segments 131-1 are directly connected to the first pulling member 122 or connected to the first pulling member 122 through the connecting tube 123. The proximal end of the first pulling member 122 can be connected to the operating part 110.

[0105] In some embodiments, the stiffness of the first connecting segment 131 is less than the stiffness of the second connecting segment 132. Preferably, the ratio of the stiffness of the first connecting segment 131 to the stiffness of the second connecting segment 132 can range from 0.2 to 0.9, more preferably from 0.3 to 0.8. For example, the stiffness of the first connecting segment 131 can range from 50 to 400 N / m, and the stiffness of the second connecting segment 132 can range from 200 to 1000 N / m. Preferably, the stiffness of the first connecting segment 131 can range from 110 N / m, and the stiffness of the second connecting segment 132 can range from approximately 300 N / m. By further limiting the stiffness ranges of the first connecting segment 131 and the second connecting segment 132, the snare portion 130 can be prevented from becoming elongated while ensuring smooth operation of the snare 100 by the operator. In some embodiments, the stiffness of the first connecting segment 131 can be made smaller than the stiffness of the second connecting segment 132 through various settings. For more details on how to make the stiffness of the first connecting segment 131 smaller than the stiffness of the second connecting segment 132, please refer to the following description.

[0106] In some embodiments of the present specification, the stiffness of the second connecting segment 132 located at the distal end of the snare portion 130 is set to be greater than the stiffness of the first connecting segment 131 located at the proximal end of the second connecting segment 132. This allows the second connecting segment 132 located at the distal end of the snare portion 130 to provide more tension in the radial direction B when the snare portion 130 contracts into the connecting portion 120, so as to offset the force in the axial direction A caused by the contraction of the snare portion 130, reduce the radial deformation of the snare portion 130 during contraction, and prevent the snare portion 130 from becoming gradually slender, making it easier to snare the lesion. Of course, when the snare portion 130 contacts the lesion, the stiffness of the second connecting segment 132 also provides a pressing force toward the lesion, thereby improving the fit and stability between the snare portion 130 and the tissue.

[0107] In some embodiments of the present disclosure, the snare portion 130 of the snare 100 includes a first connecting section 131 and a second connecting section 132 . During operation, as the snare is tightened, the size of the snare portion changes as shown in the following table.

[0108] As can be seen from the table above, some embodiments of the present specification, by configuring the snare of the snare 100 to have a first connecting segment 131 and a second connecting segment 132 of different stiffnesses, can stabilize the snare shape changes during the operation of the snare 100, prevent the snare portion 130 from becoming gradually slender, ensure the integrity of the snare portion 130 wrapping around the lesion, and improve the efficiency and completeness of the cutting.

[0109] In some embodiments, the second rigid portion may further include a third connecting segment 133. Fig. 4 is a schematic diagram of a snare according to the aforementioned embodiment of this specification.

[0110] As shown in Figures 4 and 5, the snare portion 130 may include a first connecting segment 131, a second connecting segment 132, and a third connecting segment 133, wherein the third connecting segment 133 is located proximal to the first connecting segment 131. The third connecting segment 133 may have a symmetrical structure with the axial axis of the snare 100 as the axis of symmetry, or an asymmetrical structure. For example, the third connecting segment 133 and the first connecting segment 131 shown in Figure 4 may both have a symmetrical structure with the axial axis of the snare 100 as the axis of symmetry, in which case the third connecting segment 133 as a whole is located proximal to the first connecting segment 131 as a whole. For another example, the third connecting segment 133 and / or the first connecting segment 131 may be an asymmetric structure with the axial axis of the snare 100 as the symmetry axis. For example, the third connecting segments 133 on both sides of the axis of the snare 100 are of different lengths in the axial direction A, and / or the first connecting segments 131 on both sides of the axis of the snare 100 are of different lengths in the axial direction A. In this case, the proximal end of the third connecting segment 133 is located proximal to the proximal end of the first connecting segment 131 (i.e., the distance from the operating portion 110 is smaller).

[0111] In some embodiments, as shown in Figures 4 and 5, the two ports at the proximal end of the first connecting segment 131 are respectively connected to the two ports at the distal end of the third connecting segment 133, and the two ports at the distal end of the first connecting segment 131 are respectively connected to the two ports at the proximal end of the second connecting segment 132. The two ports at the proximal end of the third connecting segment 133 can be connected to the operating portion 110 via the first pulling member 122. The proximal and distal ports of a sub-connecting segment 131-1 constituting the first connecting segment 131 are respectively connected to a port at the distal end of the third connecting segment 133 and a port at the proximal end of the second connecting segment 132, and the proximal and distal ports of another sub-connecting segment 131-1 are respectively connected to another port at the distal end of the third connecting segment 133 and another port at the proximal end of the second connecting segment 132.

[0112] In some embodiments, the stiffness of the first connecting segment 131 is less than that of the second connecting segment 132, and the stiffness of the first connecting segment 131 is less than that of the third connecting segment 133. For example, the stiffness of the first connecting segment 131 may be approximately 50 to 400 N / m, and the stiffness of the second and third connecting segments 132, 133 may be approximately 200 to 1000 N / m. Preferably, the stiffness of the first connecting segment 131 may be 110 N / m, and the stiffness of the second and third connecting segments 132, 133 may both be 300 N / m. In some embodiments, the stiffness of the first connecting segment 131 may be less than that of the second and third connecting segments 132, 133 through various configurations. For more information on how to configure the stiffness of the first connecting segment 131 to be less than that of the second and third connecting segments 132, and vice versa, please refer to the following sections of this specification.

[0113] As shown in FIG6A , when the portion of the snare portion of the snare connected to the connecting portion has low rigidity, the snare portion has difficulty applying force to the lesion 200, failing to ensure a good fit between the snare portion and the lesion 200. As shown in FIG6B , when the third connecting segment 133 has high rigidity, the operator can adjust the direction and angle of the snare portion 130 when using the snare 100 so that the third connecting segment 133 can apply force to the lesion 200, thereby deforming the lesion 200 and ensuring a tighter fit between the snare portion 130 and the lesion 200. In some embodiments of the present disclosure, a third connecting section 133 having a greater rigidity than the first connecting section 131 is provided between the first connecting section 131 and the connecting portion 120. This ensures that the snare shape changes stably during operation of the snare 100, prevents the snare portion 130 from becoming gradually elongated, and ensures that the snare portion 130 in the snare 100 fits more closely to the lesion 200, thereby improving the efficiency and completeness of the cutting.

[0114] Furthermore, it is understood that when an operator uses a snare, if the portion of the snare portion connected to the connecting portion has low rigidity, the snare portion may deform toward its center of gravity when the snare is in mid-air due to the influence of gravity, shortening the radial distance of the snare portion. However, some embodiments of the present disclosure provide a third connecting segment 133 with greater rigidity than the first connecting segment 131 between the first connecting segment 131 and the connecting portion 120. This can reduce the deformation of the snare portion 130 in mid-air, prevent the radial distance of the snare portion from shortening, and facilitate the snare 100's capture of the lesion.

[0115] In some embodiments, the stiffness of the third connecting segment 133 can be the same as the stiffness of the second connecting segment 132. By setting the stiffness of the third connecting segment 133 and the second connecting segment 132 to the same value, the snare 100 can be uniformly adjusted during use, making it easier for the operator to monitor the snare progress. When the snare 100 is used to snare a polyp with uniform overall hardness, the stiffness of the third connecting segment 133 can be equal to the stiffness of the second connecting segment 132, ensuring that the snare portion 130 contacts and conforms to the entire tissue of the polyp. Preferably, when the stiffness of the third connecting segment 133 is the same as that of the second connecting segment 132, the ratio of the stiffness of the first connecting segment 131 to the stiffness of the second connecting segment 132 is in the range of 0.2 to 0.9, preferably 0.3 to 0.8. By limiting the stiffness of the first connecting segment 131 and the second connecting segment 132 based on this ratio range, the changes in the axial direction A and radial direction B of the snare portion 130 can be more stable, facilitating operator control. For example, the stiffness of the first connecting segment 131 can be 310 N / m, and the stiffness of the third connecting segment 133 and the stiffness of the second connecting segment 132 can both be 635 N / m.

[0116] In some embodiments, the stiffness of the third connecting segment 133 can be greater than that of the second connecting segment 132. For example, the stiffness of the third connecting segment 133 can be 635 N / m, while the stiffness of the second connecting segment 132 can be 390 N / m. By setting the stiffness of the third connecting segment 133 to be greater than that of the second connecting segment 132, the snare 100 can maintain its shape before snaring, preventing deformation and facilitating snaring of the lesion. When the snare 100 is used to snare a proximal polyp with relatively hard tissue, the stiffness of the third connecting segment 133 can be greater than that of the second connecting segment 132, ensuring stable contact between the snare portion 130 and the proximal end of the polyp. Preferably, when the stiffness of the third connecting segment 133 is greater than that of the second connecting segment 132, the ratio of the stiffness of the second connecting segment 132, the stiffness of the first connecting segment 131, and the stiffness of the third connecting segment 133 is in the range of (1.1-3.4):1:(1.4-3.6), preferably (1.25-3.3):1:(1.5-3.5). Setting the ratio based on this ratio range can further improve the snare success rate of the snare 100. It will be understood that the aforementioned ratio range is set under the premise that the stiffness of the third connecting segment 133 is greater than the stiffness of the second connecting segment 132, that is, the value of the third connecting segment 133 within the ratio range must be greater than the value of the second connecting segment 132 within the ratio range.

[0117] In some embodiments, the stiffness of the third connecting segment 133 can be less than that of the second connecting segment 132. For example, the stiffness of the third connecting segment 133 can be 390 N / m, while the stiffness of the second connecting segment 132 can be 635 N / m. By setting the stiffness of the third connecting segment 133 to be less than that of the second connecting segment 132, the operator can cut the snare even with less force. When the snare 100 is used to snare a hard distal polyp, the stiffness of the second connecting segment 132 can be greater than that of the third connecting segment 133, ensuring stable contact between the snare portion 130 and the distal end of the polyp. Preferably, when the stiffness of the third connecting segment 133 is less than that of the second connecting segment 132, the ratio of the stiffness of the second connecting segment 132, the stiffness of the first connecting segment 131, and the stiffness of the third connecting segment 133 is in the range of (1.1-3.5):1:(1-3.2), preferably (1.25-3.3):1:(1-3). Setting based on this ratio range can facilitate the operator to cut the lesion and reduce the operator's operating difficulty. It can be understood that the aforementioned ratio range is set on the premise that the stiffness of the third connecting segment 133 is less than the stiffness of the second connecting segment 132, that is, the value of the third connecting segment 133 in the ratio range must be less than the value of the second connecting segment 132 in the ratio range.

[0118] In some embodiments of the present specification, the snare portion 130 of the snare 100 includes a first connecting segment 131 , a second connecting segment 132 , and a third connecting segment 133 . During operation, as the snare is tightened, the size of the snare portion changes as shown in the following table.

[0119] As can be seen from the above table, some embodiments of the present specification can stabilize the changes in the snare shape during operation of the snare 100 by configuring the snare of the snare 100 to include a first connecting segment 131, a second connecting segment 132, and a third connecting segment 133, wherein the second connecting segment 132 has a greater stiffness than the first connecting segment 131. This prevents the snare portion 130 from becoming gradually elongated, ensures the integrity of the snare portion 130 wrapping around the lesion, and improves the efficiency and completeness of the cutting. By setting the stiffness of the third connecting segment 133 located at the proximal end of the snare portion 130 to be greater than the stiffness of the first connecting segment 131 located at the distal end of the third connecting segment 133, the snare portion 130 can press downward against the root of the lesion through the third connecting segment 133 with greater stiffness when contacting and snares the lesion (the stiffness of the third connecting segment 133 provides a pressing force toward the lesion), thereby avoiding the snare portion 130 and the lesion from slipping easily, thereby improving the fit, stability, success rate and accuracy of the snare; of course, the stiffness of the third connecting segment 133 can also reduce the radial deformation of the proximal end of the snare portion 130 during contraction, making it easier to snare tissue.

[0120] In some embodiments, the first rigid part and the second rigid part can be an integral structure or a non-integrated structure. When the first rigid part and the second rigid part are non-integrated structures, the first rigid part and the second rigid part can be connected by a variety of connection processes. The aforementioned connection process may include but is not limited to one or more of laser welding, brazing, plasma welding, argon arc welding, turning and forging. Preferably, the first rigid part and the second rigid part can be connected by one or more of laser welding, brazing and turning and forging, thereby increasing the rigidity of the connection between the first rigid part and the second rigid part, avoiding the snare part 130 from becoming slender during operation, and ensuring the fitting and removal of the lesion. For more description of the case where the first rigid part and the second rigid part are an integral structure, please refer to the relevant description below in this manual.

[0121] In some embodiments, at least a portion of the one of the first rigid portion and the second rigid portion that is closer to the first pulling member 122 is fixedly connected to the first pulling member 122 .

[0122] When the second rigid portion only includes the second connecting segment 132, the structure of the first rigid portion and the second rigid portion that is closer to the first traction member 122 is the first connecting segment 131, and the first connecting segment 131 can be fixedly connected to the first traction member 122. The proximal end of the first connecting segment 131 can be directly or indirectly connected to the distal end of the first traction member 122. As shown in Figure 2, the proximal end of the first connecting segment 131 can be connected to the distal end of the connecting tube 123, and the proximal end of the connecting tube 123 can be connected to the distal end of the first traction member 122. Since the proximal end of the first traction member 122 is connected to the first sliding member 112, the sliding of the first sliding member 112 can drive part or all of the snare portion 130 to extend out of or enter the sheath tube 121, thereby causing the snare portion 130 to deform.

[0123] When the second rigid portion further includes a third connecting segment 133, the structure of the first or second rigid portion that is closer to the first pulling member 122 is the third connecting segment 133, and the third connecting segment 133 can be fixedly connected to the first pulling member 122. As shown in Figure 4, the proximal end of the third connecting segment 133 can be connected to the first pulling member 122. In some optional embodiments, the proximal end of the third connecting segment 133 can be integrally formed with the first pulling member 122. This arrangement can simplify the production process of the third connecting segment 133 and the first pulling member 122, ensure the stability of the connection between the third connecting segment 133 and the first pulling member 122, and prevent the third connecting segment 133 from falling off. In other embodiments, the proximal end of the third connecting segment 133 can be fixedly connected to the first pulling member 122. For example, the proximal end of the third connecting segment 133 can be fixedly connected to the first pulling member 122 through one or more of laser welding, brazing, and turning. Since the proximal end of the third connecting section 133 can be connected to the first traction member 122, and the first traction member 122 is also connected to the first sliding member 112, the sliding of the first sliding member 112 can drive part or all of the snare portion 130 to extend out or enter the sheath 121, thereby causing the snare portion 130 to deform.

[0124] The following describes how to configure the first and second rigidity portions so that the rigidity of the first rigidity portion is less than that of the second rigidity portion. It will be appreciated that the snare 100 can utilize one or more of the following configurations to ensure a difference in rigidity between the first and second rigidity portions. For example, the first characteristic dimension of the first connecting segment 131 and the second characteristic dimension of the second connecting segment 132 may be the same, but the hardness of the second connecting segment 132 may be greater than that of the first connecting segment 131, thereby increasing the rigidity of the second connecting segment 132 relative to the first connecting segment 131. Furthermore, when the second rigidity portion includes the second connecting segment 132 and the third connecting segment 133, the configurations that create a difference in rigidity between the second and third connecting segments and the first connecting segment 131 may be the same or different.

[0125] In some embodiments, components in the first rigid portion and the second rigid portion may have different stiffness due to different hardness.

[0126] In some embodiments, the hardness of the second connecting segment 132 is greater than that of the first connecting segment 131 to ensure that the stiffness of the first connecting segment 131 is less than that of the second connecting segment 132. For example, the hardness of the second connecting segment 132 can differ from the hardness of the first connecting segment 131 by 5 to 10 HRB. For example, the hardness of the second connecting segment 132 can be 80 to 95 HRB, while the hardness of the first connecting segment 131 can be 70 to 85 HRB. Preferably, the hardness of the second connecting segment 132 can be 85 to 90 HRB, while the hardness of the first connecting segment 131 can be 75 to 80 HRB. This ensures uniform changes in the snare portion 130 while reducing operator difficulty.

[0127] The second connecting segment 132 and the first connecting segment 131 can be made of different materials, provided that the hardness of the first connecting segment 131 is less than that of the second connecting segment 132. The second connecting segment 132 and the first connecting segment 131 can also be made of the same material. When the second connecting segment 132 and the first connecting segment 131 are made of the same material, the hardness of the second connecting segment 132 can be increased through a hardening process (e.g., one or more of heat treatment, work hardening, alloying, and grain refinement).

[0128] Similarly, the hardness of the third connecting segment 133 may also be greater than the hardness of the first connecting segment 131 to ensure that the stiffness of the first connecting segment 131 is less than the stiffness of the third connecting segment 133 .

[0129] In some embodiments, components in the first rigid portion and the second rigid portion may have different stiffnesses due to different characteristic sizes.

[0130] In some embodiments, the first characteristic dimension is smaller than the second characteristic dimension, where the first characteristic dimension is the characteristic dimension of a cross section of the first connecting segment 131 perpendicular to the axial direction of the first connecting segment 131, and the second characteristic dimension is the characteristic dimension of a cross section of the second connecting segment 132 perpendicular to the axial direction of the second connecting segment 132. The aforementioned characteristic dimensions may reflect the minimum dimension of the shape characteristics of the cross section. For example, when the cross section is elliptical, the dimensions that characterize the cross section may include the major axis and the minor axis, and the characteristic dimension may be the minor axis. For another example, when the cross section is rectangular, the dimensions that characterize the cross section may include the length and the width, and the characteristic dimension may be the smaller of the length and the width. For another example, when the cross section is circular, the dimensions that characterize the cross section may include the diameter, and the characteristic dimension may be the diameter. For another example, when the cross section is triangular, the dimensions that characterize the cross section may include the height and the base, and the characteristic dimension may be the smaller of the height and the base.

[0131] In some embodiments, the first characteristic dimension may be smaller than the second characteristic dimension, and the two may be of the same type. As shown in Figure 3, the first characteristic dimension of a cross section NN of the first connecting segment 131 perpendicular to the axis of the first connecting segment 131 is smaller than the second characteristic dimension of a cross section MM of the second connecting segment 132 perpendicular to the axis of the second connecting segment 132. For example, when the cross section NN corresponding to the first connecting segment 131 and the cross section MM corresponding to the second connecting segment 132 are both circular, the first characteristic dimension and the second characteristic dimension may be the diameters of the cross sections NN and MM, respectively, with the diameter of the cross section MM being greater than the diameter of the cross section NN. In some embodiments, the difference between the second characteristic dimension and the first characteristic dimension may be 0.1 to 0.2 mm. For example, the diameters of the cross sections NN and MM may be 0.30 mm and 0.40 mm, respectively. For another example, the diameters of the cross sections NN and MM may be 0.25 mm and 0.35 mm, respectively. For another example, the diameters of the cross sections NN and MM may be 0.20 mm and 0.40 mm, respectively. Preferably, the ratio of the first characteristic dimension to the second characteristic dimension ranges from 0.5 to 0.95, and more preferably, from 0.6 to 0.9.

[0132] In some embodiments, the first characteristic dimension may be smaller than the second characteristic dimension and may be of different types. For example, if the cross-section corresponding to the first connecting segment 131 is circular, the first characteristic dimension may be the diameter of the circular cross-section, and if the cross-section corresponding to the second connecting segment 132 is elliptical, the second characteristic dimension may be the minor axis of the elliptical cross-section.

[0133] Similarly, the first characteristic dimension is smaller than the third characteristic dimension, wherein the third characteristic dimension is the characteristic dimension of the cross section of the third connecting segment 133 perpendicular to the axial direction of the third connecting segment 133. In some embodiments, the first characteristic dimension and the third characteristic dimension may be of the same type. For example, when the cross section NN corresponding to the first connecting segment 131 and the cross section OO corresponding to the third connecting segment 133 may both be circular, the aforementioned first characteristic dimension and the third characteristic dimension may be the diameters of the cross section NN and the cross section OO, respectively, and the diameter of the cross section OO should be greater than the diameter of the cross section NN. In some embodiments, the difference between the characteristic dimensions corresponding to the first characteristic dimension and the third characteristic dimension may be 0.1 to 0.2 mm. For example, the diameters of the cross section NN and the cross section OO may be 0.30 mm and 0.40 mm, respectively. Preferably, the ratio of the first characteristic dimension to the third characteristic dimension ranges from 0.5 to 0.95, preferably from 0.6 to 0.9.

[0134] In some embodiments, the components in the first rigid portion and the second rigid portion may have different stiffnesses due to different numbers of minimum units.

[0135] In some embodiments, when the absolute value of the difference between each characteristic dimension is less than or equal to 0.1 mm (preferably 0.05 mm), each connecting unit in the portion with a larger number of strands is thinner, and each connecting unit in the portion with a smaller number of strands is thicker. As shown in FIG9 , the first connecting segment 131 is composed of at least two first connecting units 131-a, and the second connecting segment 132 is composed of at least one second connecting unit (not shown in the figure). The first connecting unit 131-a and the second connecting unit can be the smallest units constituting the first connecting segment 131 and the second connecting segment 132, respectively. It can be understood that the first connecting segment 131 and the second connecting segment 132 are strip structures, and correspondingly, the first connecting unit 131-a and the second connecting unit can also be strip structures. The material of the aforementioned first connecting unit 131-a and the second connecting unit can be one or more of nickel titanium, 304 stainless steel or other feasible materials.

[0136] In some embodiments, multiple strands of first connecting units 131-a can be combined through various merging processes to form a corresponding first connecting segment 131. Each first connecting unit can be seen on any cross-section of the first connecting segment 131 perpendicular to its axis. As shown in FIG9 , a first connecting segment 131 is composed of seven first connecting units 131-a. Seven first connecting units 131-a can be seen on any cross-section of the first connecting segment 131 perpendicular to its axis. For example, multiple strands of first connecting units 131-a can be arranged and then deformed by rotation to secure the multiple strands of first connecting units 131-a to form a first connecting segment 131. For another example, multiple first connecting units 131-a can be connected and secured by welding, gluing, or the like to form a first connecting segment 131. Similarly, multiple strands of second connecting units can be combined through the aforementioned various merging processes to form a corresponding second connecting segment 132.

[0137] In some embodiments, the first number of strands is greater than the second number of strands to ensure that the stiffness of the first connecting segment 131 is less than the stiffness of the second connecting segment 132. The first number of strands refers to the number of strands in the first connecting unit 131-a that makes up the first connecting segment 131, and the second number of strands refers to the number of strands in the second connecting unit that makes up the second connecting segment 132. For example, the second number of strands is 7 and the first number of strands is 19. For another example, the second number of strands is 3 and the first number of strands is 7.

[0138] It is understood that, for example, when the first number of strands is 2 and the second number of strands is 1, and the characteristic dimensions of the first connecting unit 131-a and the second connecting unit are the same, even if the first number of strands is greater than the second number of strands, the stiffness of the first connecting segment 131 should be greater than the stiffness of the second connecting segment 132. Therefore, when differentiating the stiffness of different rigid components based on the number of strands, it is necessary to limit the characteristic dimensions of the different rigid components. To ensure that the difference in the number of strands can be reflected in the difference in stiffness, the absolute value of the difference in the characteristic dimensions between the first connecting segment 131 and the second connecting segment 132 is less than or equal to a first predetermined difference threshold. More preferably, except for the number of strands of the connecting units (i.e., the first connecting segment 131-a and the second connecting unit), the first connecting segment 131 and the second connecting segment 132 are identical or similar. For example, the difference in characteristic dimensions, cross-sectional shape, and physical and chemical properties between the first connecting segment 131 and the second connecting segment 132 is zero or within 5%. In some embodiments, when the difference between the first characteristic dimension and the second characteristic dimension is less than a first preset difference threshold, the first number of strands is greater than the second number of strands to ensure that the stiffness of the first connecting segment 131 is less than the stiffness of the second connecting segment 132. The first preset difference threshold is the range of difference between the first characteristic dimension and the second characteristic dimension when evaluating the first and second connecting segments 131, 132 based on the number of strands. In some embodiments, the first preset difference threshold can be 0 to 0.1 mm, preferably any value between 0 and 0.05 mm. For example, the first preset difference threshold can be 0. For another example, the first preset difference threshold can also be 0.02 mm or 0.05 mm.

[0139] In some embodiments, the third connecting segment 133 is composed of at least one strand of third connecting units, with the first number of strands being greater than the third number of strands, where the third number of strands represents the total number of third connecting units comprising the third connecting segment 133. The third connecting units may also be made of one or more of nickel-titanium, 304 stainless steel, or other suitable materials. Similarly, to ensure that the difference in strand number reflects a difference in stiffness, the difference in characteristic dimensions between the first connecting segment 131 and the third connecting segment 133 is less than or equal to a second predetermined difference threshold. More preferably, the first connecting segment 131 and the third connecting segment 133 are identical or similar, except for the number of strands of the connecting units (i.e., the first connecting unit 131-a and the third connecting unit). For example, the difference in characteristic dimensions, cross-sectional shapes, and physical and chemical properties between the first connecting segment 131 and the third connecting segment 133 is zero or within 5 percent. In some embodiments, when the difference between the first and third characteristic dimensions is less than the second predetermined difference threshold, the first number of strands is greater than the third number of strands to ensure that the stiffness of the first connecting segment 131 is less than that of the third connecting segment 133. The second preset difference threshold is the difference range between the first characteristic dimension and the third characteristic dimension when evaluating the first connecting segment 131 and the third connecting segment 133 based on the number of strands. In some embodiments, the second preset difference threshold can be any value between 0 and 0.1 mm, preferably between 0 and 0.05 mm.

[0140] In some embodiments, components of the first rigid portion and the second rigid portion may have different stiffness due to different cross-sectional shapes.

[0141] In some embodiments, the second cross-section can be configured as one or more of a circle, a square, and a hexagon, and the first cross-section can be configured as one or more of a semicircle, a triangle, and a rectangle, wherein the first cross-section is a cross-section of the first connecting segment 131 perpendicular to the axial direction of the first connecting segment 131, and the second cross-section is a cross-section of the second connecting segment 132 perpendicular to the axial direction of the second connecting segment 132. It is worth noting that, when the material, cross-sectional area, and physical and chemical properties are the same or similar (for example, the difference is within 5%), since the cross-sectional shapes of a circle, square, hexagon, etc. have a more uniform distribution of dimensions in all directions than those of a semicircle, triangle, or rectangle, the rigidity of the structure with a cross-sectional shape of a circle, square, or hexagon can be greater than that of the structure with a cross-sectional shape of a semicircle, triangle, or rectangle.

[0142] Similarly, the third cross-section can be set to one or more of circular, square, and hexagonal shapes, the first cross-section can be set to one or more of semicircular, triangular, and rectangular shapes, and the third cross-section is a cross-section of the third connecting segment 133 perpendicular to the axial direction of the third connecting segment 133.

[0143] By providing the third connecting segment 133 , the first connecting segment 131 , and the second connecting segment 132 with different cross-sectional shapes, the third connecting segment 133 , the first connecting segment 131 , and the second connecting segment 132 may have different stiffnesses.

[0144] In some embodiments, the first rigid portion and the second rigid portion may have different stiffnesses due to the stiffness reinforcement.

[0145] In some embodiments, the second connecting segment 132 may include a base connecting segment and a stiffening member, wherein the stiffening member is fixed to the base connecting segment. For example, the second connecting segment 132 shown in Figure 10 may include a base connecting segment 132-1 and a stiffening member 132-2, wherein the stiffening member 132-2 may be spirally wound around the base connecting segment 132-1, thereby increasing the stiffness of the second connecting segment 132. For another example, the second connecting segment 132 shown in Figure 11 may include a base connecting segment 132-1 and a stiffening member 132-2, wherein the stiffening member 132-2 may be a tubular material disposed outside the base connecting segment 132-1. The tubular material may be a flexible material. The cross-section of the tubular material perpendicular to its axial direction may be of various shapes (e.g., triangular, rectangular, square, etc.). For example, the stiffening member may also include a medical coating disposed outside the base connecting segment, wherein the medical coating may increase the stiffness of the second connecting segment 132.

[0146] In some embodiments, the stiffness of the stiffness reinforcement member can be greater than the stiffness of the first connecting segment 131. For example, the stiffness reinforcement member may include, but is not limited to, nickel titanium, titanium alloy, stainless steel, etc., which have a stiffness greater than that of the first connecting segment 131. In some embodiments of this specification, by separately providing the basic connecting segment and the stiffness reinforcement member, it is convenient to adjust the structure and material of the stiffness reinforcement member, thereby conveniently adjusting the stiffness of the second connecting segment 132 as needed.

[0147] In some embodiments, the second connecting segment 132, which is composed of a basic connecting segment and a stiffening member, can be connected to the first connecting segment 131 in various ways. For example, the basic connecting segment and the stiffening member can be combined, and the two ports at the distal end of the first connecting segment 131 can be connected to the two ports at the distal end of the combined basic connecting segment and stiffening member in the second connecting segment 132 by various connection processes (e.g., welding, gluing).

[0148] In some embodiments, the first connecting segment 131 and the base connecting segment can be an integral structure. As shown in Figures 10 and 11, the first connecting segment 131 and the base connecting segment 132-1 can be an integral structure. The first connecting segment 131 and the base connecting segment can be made of the same material and have the same cross-sectional dimensions, and can be produced through one-piece molding, thereby reducing production costs. In addition, the user of the snare 100 can flexibly select the location of the stiffening member based on actual needs (e.g., lesion shape) to ensure that the snare portion 130 can better fit the lesion during use. In some embodiments of the present specification, by configuring the first connecting segment 131 and the base connecting segment as an integral structure, it is possible to modify existing snares, install stiffening members as needed, prevent the snare portion 130 from becoming slender during use, and further reduce the production cost of the improved snare 100.

[0149] In some embodiments, similar to the second connecting segment 132 , the third connecting segment 133 may also include a basic connecting segment and a stiffening member, wherein the stiffening member is fixed to the basic connecting segment.

[0150] In some embodiments, components of the first rigid portion and the second rigid portion may have different rigidities due to the curvature of the arc-shaped structure.

[0151] As shown in Figure 2, when both the first connecting segment 131 and the second connecting segment 132 include arcuate structures, the curvature of the arcuate structure of the first connecting segment 131 can be smaller than that of the arcuate structure of the second connecting segment 132 to increase the stiffness of the second connecting segment 132, thereby reducing the stiffness of the first connecting segment 131 relative to the stiffness of the second connecting segment 132. For example, the radius of curvature of the first connecting segment 131 can be 15 to 55 mm, and the radius of curvature of the second connecting segment 132 can be 6 to 17 mm. Preferably, the radius of curvature of the first connecting segment 131 can be 20 to 50 mm, and the radius of curvature of the second connecting segment 132 can be 8 to 15 mm. By further limiting the curvature radii of the two connecting segments, the shape of the snare portion 130 can be ensured to facilitate lesion removal. Preferably, the ratio of the curvature of the arcuate structure of the first connecting segment 131 to the curvature of the arcuate structure of the second connecting segment 132 can range from 0.1 to 0.85, preferably from 0.16 to 0.75.

[0152] In some embodiments of this specification, the components of the first rigid portion and the second rigid portion can generate a stiffness difference through one or more of the aforementioned settings. It is worth noting that when the stiffness of the second connecting section 132 and the third connecting section 133 is different, a stiffness difference can also be generated through similar settings.

[0153] In some embodiments, the snare portion 130 includes a base portion 1301 and an adjusting portion 1302 , and the adjusting portion 1302 is slidably connected to the base portion 1301 .

[0154] The base portion 1301 can be used to control the overall shape and size of the snare portion 130. Each part of the base portion 1301 has the same rigidity.

[0155] The adjusting portion 1302 is used to adjust the rigidity of various positions of the snare portion 130. The adjusting portion 1302 may include a first rigid portion and a second rigid portion. As shown in FIG12A , the adjusting portion 1302 may include the first connecting segment 131 and the second connecting segment 132 described above.

[0156] The base portion 1301 and the adjustment portion 1302 are of the same or similar size and shape and together constitute the snare portion 130. For example, the base portion 1301 and the adjustment portion 1302 may differ only in the presence of a guide structure 134 on the base portion 1301. Two ports at the proximal end of the base portion 1301 are connected to the distal end of the first pulling member 122. The operating unit 110 can control the base portion 1301 to partially or completely extend or retract into the sheath 121 via the first pulling member 122. The base portion 1301 and the adjustment portion 1302 may be made of the same or different materials.

[0157] In some embodiments, the adjustment portion 1302 can slide relative to the base portion 1301 to adjust the relative positions of the first rigid portion and the second rigid portion in the snare portion 130, thereby adjusting the stiffness of various positions of the snare portion 130. Figures 12A and 12B are enlarged schematic views of the same portion of the snare portion 130. An operator can adjust the position of the adjustment portion 1302 in the snare portion 130 shown in Figure 12A. The adjustment portion 1302 can slide relative to the base portion 1301 to obtain the snare portion 130 shown in Figure 12B. In the snare portion 130 shown in Figure 12B, the positions of the first connecting segment 131 and the second connecting segment 132 of the adjustment portion 1302 in the snare portion 130 are different from those in the snare portion 130 shown in Figure 12A.

[0158] In some embodiments, the adjustment portion 1302 may further include a stiffness adjustment wire (not shown). As shown in FIG13 , the adjustment portion 1302 is provided with a first adjustment channel 136 , and the stiffness adjustment wire is detachably provided in the first adjustment channel 136 to adjust the stiffness of the adjustment portion 1302 .

[0159] In some embodiments, the adjusting portion 1302 and the base portion 1301 may be arranged in various ways to enable the adjusting portion 1302 to slide relative to the base portion 1301 .

[0160] In some embodiments, as shown in FIG12A , a plurality of connecting rings 135 are provided on the base portion 1301, and the adjusting portion 1302 passes through the connecting rings 135 and is slidably connected to the base portion 1301. The base portion 1301 can be fixedly connected to the plurality of connecting rings 135, and the adjusting portion 1302 can slide relative to the base portion 1301 under the drive of the operating portion 110. When the adjusting portion 1302 slides relative to the base portion 1301, the positions of the base portion 1301 and the connecting rings 135 do not change.

[0161] In some embodiments, as shown in FIG13 , a second adjustment channel 137 may be provided in the base portion 1301, and the adjustment portion 1302 may be slidably provided in the second adjustment channel 137. The operating portion 110 may drive the adjustment portion 1302 to slide within the second adjustment channel 137. When the adjustment portion 1302 slides within the second adjustment channel 137, the position of the base portion 1301 itself does not change.

[0162] In some embodiments, the operating portion 110 can manipulate the adjustment portion 1302 to slide relative to the base portion 1301. The connecting portion 120 can also include a second traction member 126 disposed within the sheath 121. The second traction member 126 and the first traction member 122 are both configured to move axially along the sheath 121, and the second traction member 126 can slide relative to the first traction member 122. The second traction member 126 can be connected to the adjustment portion 1302. For example, the second traction member 126 shown in FIG14 can include a first traction cable 126-1 and a second traction cable 126-2. The distal end of the first traction cable 126-1 is connected to a port on the proximal end of the adjustment portion 1302, and the distal end of the second traction cable 126-2 is connected to another port on the proximal end of the adjustment portion 1302. The operating portion 110 can control the first pulling cable 126 - 1 and the second pulling cable 126 - 2 to slide along the axial direction of the sheath tube 121 , thereby driving the adjusting portion 1302 to slide relative to the base portion 1301 .

[0163] In some embodiments, the operating portion 110 can synchronously drive the base portion 1301 and the adjustment portion 1302 to partially or completely extend or enter the sheath 121. In some embodiments, a limiting structure can be provided on the first pulling member 122. The limiting structure can limit the second pulling member 126 to the first pulling member 122, enabling the operating portion 110 to synchronously drive the base portion 1301 and the adjustment portion 1302 to partially or completely extend or enter the sheath 121, and the second pulling member 126 can slide relative to the first pulling member 122 within the limiting structure. For example, the limiting structure can be the limiting ring 127 shown in Figure 14. The aforementioned limiting ring 127 is fixedly connected to the first traction member 122, and the proximal ends of the first traction rope 126-1 and the second traction rope 126-2 are connected through the through hole in the limiting ring 127 and can slide in the through hole in the limiting ring 127. The sliding of the first sliding member 112 can drive the first traction member 122 to move along the axial direction A, and synchronously drive the limiting ring 127 and the second traction member 126 arranged in the limiting ring 127 to move along the axial direction A, thereby synchronously driving part or all of the base part 1301 and the adjustment part 1302 to extend or enter the sheath 121. For another example, the limiting structure can also be a pulley. The aforementioned pulley rotating shaft can be fixedly set on the first traction member 122, and the proximal ports of the first traction rope 126-1 and the second traction rope 126-2 can be wound around the slide groove of the pulley. The sliding of the first sliding member 112 can drive the first traction member 122 to move along the axial direction A, and synchronously drive the pulley and the second traction member 126 set on the pulley to move along the axial direction A, thereby synchronously driving part or all of the base part 1301 and the adjustment part 1302 to extend out or enter the sheath 121.

[0164] In some embodiments, the adjusting member may further include a second adjusting member, which may be used to drive the adjusting portion 1302 to slide relative to the base portion 1301. For example, when the limiting structure is a limiting ring 127, the second adjusting member may be a sliding block, and the number of sliding blocks may be one or two. The sliding block may be fixedly connected to the first traction cable 126-1 or the second traction cable 126-2 and extend from the handle 111. The operator may slide the sliding block along the axial direction A of the snare 100, driving the first traction cable 126-1 and / or the second traction cable 126-2 to slide along the axial direction A of the snare 100, thereby driving the adjusting portion 1302 to slide relative to the base portion 1301. Since the limiting ring 127 is provided on the first traction member 122, the adjusting portion 1302 is ensured to slide relative to the base portion 1301 while the adjusting portion 1302 as a whole does not move along the axial direction A. For another example, when the limiting structure is a pulley, the second adjusting member can also be a knob, which is connected to the pulley through the handle 111. The operator can turn the knob to drive the pulley to rotate, causing the first traction rope 126-1 and the second traction rope 126-2 to slide along the axial direction A of the snare 100, thereby driving the adjusting part 1302 to slide relative to the base part 1301.

[0165] In some embodiments of the present specification, the adjustment portion 1302 can slide relative to the base portion 1301 through one or more of the aforementioned settings. When the overall size of the snare portion 130 is determined, the operator can also adjust the stiffness of different positions of the snare portion 130 through the adjustment portion 1302, thereby adjusting the shape of the snare portion 130 as needed to meet the needs of different scenarios.

[0166] In some embodiments, the first adjusting member can control the snare portion 130 to enter the connecting portion 120 in various ways. The first adjusting member can be connected to the two ports at the proximal end of the snare portion 130 through the first pulling member 122, and the first adjusting member drives the two ports at the proximal end of the snare portion 130 to move synchronously or asynchronously.

[0167] In some embodiments, the first adjusting member may include a first sliding member 112, and the operator may control the first pulling member 122 to move along the axial direction A through the first sliding member 112, thereby driving the snare portion 130 to move along the axial direction A, forcing it to partially or completely extend out of or enter the sheath 121. For example, the first pulling member 122 may include a strip-shaped structure (e.g., the first pulling member 122 may be a pulling rope), and the two ports at the proximal end of the snare portion 130 are both connected to the distal end of the first pulling member 122. When the operating unit 110 controls the first pulling member 122 to move along the axial direction A through the first sliding member 112, the two ports at the proximal end of the snare portion 130 move synchronously, causing the snare portion 130 to partially or completely extend out of or enter the sheath 121. For another example, the first traction member 122 may also include two strip-shaped structures (e.g., the first traction member 122 may be two traction ropes), namely, a first sub-traction member and a second sub-traction member. The first slider 112 may include a first sub-slider and a second sub-slider, wherein the first sub-slider is connected to the proximal end of the first sub-traction member, the distal end of the first sub-traction member is connected to a port at the proximal end of the snare portion 130, the second sub-slider is connected to the proximal end of the second sub-traction member, and the distal end of the second sub-traction member is connected to another port at the proximal end of the snare portion 130. The first sub-slider and the second sub-slider can both slide independently to respectively drive the corresponding ports of the snare portion 130 to move along the axial direction A of the snare 100, thereby achieving asynchronous movement of the two ports at the proximal end of the snare portion 130, so that part or all of the snare portion 130 extends out of or enters the sheath 121. For example, one port at the proximal end of the snare portion 130 extends out of the sheath 121, while the other port enters the sheath 121. The first and second sub-sliders respectively control the two ports at the proximal end of the snare portion 130, so that when passing over the head of a giant polyp, the expansion range of the structures on both sides of the axis of the snare portion 130 can be continuously adjusted to quickly pass through the tissue gap. The operator can also adjust the snare angle according to the lesion through the two ports at the proximal end of the snare portion 130 to improve the success rate of the snare.

[0168] In some embodiments of the present specification, the first adjusting member drives the two ports at the proximal end of the snare portion 130 to move synchronously or asynchronously, so that the operator can control the shape of the snare portion 130 more flexibly.

[0169] In some embodiments, the first adjustment member may further include a second slider 113, through which the operator can control at least a portion of the structure of the sheath 121 to move along the axial direction A, thereby driving the snare portion 130 to partially or completely extend out of or enter the sheath 121. As shown in FIG15 , the sheath 121 may include an outer sheath 1211 and an inner sheath 1212. The outer sheath 1211 remains in a fixed position within the snare 100, while the inner sheath 1212 can move relative to the outer sheath 1211 along the axial direction A of the snare 100. The proximal end of the inner sheath 1212 can be fixedly connected to the second slider 113. The second slider 113 can slide along the axial direction A of the snare 100, driving the inner sheath 1212 to move along the axial direction A, thereby driving the snare portion 130 to partially or completely enter or extend out of the sheath 121.

[0170] It will be appreciated that when snares are performed using the first slider 112, the snare portion 130 contracts from its distal end toward its proximal end, while the sheath 121 remains in position. The proximal end of the snare portion 130 continues to retract into the sheath 121. However, the overall rigidity of the snare portion 130 is relatively low, making it prone to slipping when snares are applied to smaller lesions. When the snare 100 is also provided with the second slider 113, the snare 100 can be snared using the second slider 113. In this case, the snare portion 130 remains in position, while the inner sheath 1212 moves distally along the axial direction A to adjust the size of the snare portion 130 and snare the lesion. Because the inner sheath 1212 is more rigid than the snare portion 130, it can support the base of the lesion during snares, making even smaller lesions less likely to slip, thereby improving the success rate of snares. It is understood that, as shown in FIG15 , the snare 100 may include both a first sliding member 112 and a second sliding member 113. The operator may select the corresponding member to operate as needed, thereby increasing the operational flexibility of the snare 100. For example, the operator may snare the lesion with the second sliding member 113 and then cut the lesion with the first sliding member 112.

[0171] While the basic concepts have been described above, it will be apparent to those skilled in the art that the detailed disclosure is merely illustrative and does not limit this specification. Although not explicitly stated herein, various modifications, improvements, and revisions to this specification may be made by those skilled in the art. Such modifications, improvements, and revisions are suggested in this specification and remain within the spirit and scope of the exemplary embodiments of this specification.

[0172] This specification also uses specific terms to describe the embodiments of this specification. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "one embodiment," "an embodiment," or "an alternative embodiment" two or more times in different locations in this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of this specification may be appropriately combined.

[0173] In addition, unless expressly stated in the claims, the order of the processing elements and sequences, the use of alphanumeric characters, or the use of other names described in this specification are not intended to limit the order of the processes and methods of this specification. Although the above disclosure discusses some of the invention embodiments currently considered useful through various examples, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the spirit and scope of the embodiments of this specification. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing server or mobile device.

[0174] Similarly, it should be noted that, in order to simplify the presentation of this specification and facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this specification sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not imply that the subject matter of this specification requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single disclosed embodiment.

[0175] In some embodiments, numbers are used to describe the quantity of components and attributes. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, which may change according to the required characteristics of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of this specification are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0176] Each patent, patent application, patent application publication, and other materials, such as articles, books, specifications, publications, and documents, cited in this specification is hereby incorporated by reference in its entirety. This includes application history documents that are inconsistent with or conflict with the content of this specification, as well as documents (currently or subsequently attached to this specification) that limit the broadest scope of the claims of this specification. It should be noted that if the descriptions, definitions, and / or terminology used in the accompanying materials are inconsistent or conflicting with the content of this specification, the descriptions, definitions, and / or terminology used in this specification will control.

[0177] Finally, it should be understood that the embodiments described in this specification are intended only to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly described and illustrated in this specification.

Claims

1. A snare, characterized in that: include: A snare portion, the snare portion comprising a first rigid portion and a second rigid portion, the first rigid portion being connected to the second rigid portion, wherein at least a portion of the second rigid portion is located distally compared to the first rigid portion, and the first rigid portion has a smaller rigidity than the second rigid portion; a connecting portion capable of accommodating at least a portion of the snare portion; The operating part is connected to the snare part, and the operating part drives part or all of the snare part to extend out of or enter the connecting part.

2. The snare according to claim 1, characterized in that When the snare portion does not enter or partially enters the connecting portion, the diameter-to-length ratio of the snare portion is in the range of 0.5 to 1. The diameter-to-length ratio is the ratio of the size of the snare portion in the snare part along the radial direction of the snare to the size of the snare portion along the axial direction of the snare.

3. The snare according to claim 1, characterized in that In the process that the snare portion partially enters the connecting portion, the first change rate of the snare portion in the snare portion is not greater than the second change rate, The first change rate represents the ratio of the change in the size of the snare portion along the radial direction of the snare to the initial radial size, and the second change rate represents the ratio of the change in the size of the snare portion along the axial direction of the snare to the initial axial size.

4. The snare according to claim 1, characterized in that The first rigid portion includes a first connecting segment, and the second rigid portion includes a second connecting segment. The second connecting segment is located at a distal end compared to the first connecting segment, and the rigidity of the first connecting segment is smaller than that of the second connecting segment.

5. The snare according to claim 4, characterized in that The two ports at the distal end of the first connection segment are respectively connected to the two ports at the proximal end of the second connection segment, and the two ports at the proximal end of the first connection segment are connected to the operating part.

6. The snare according to claim 4, characterized in that When the snare portion does not enter the connecting portion, a ratio of a dimension of the second connecting section along the axial direction of the snare to a dimension of the snare portion along the axial direction of the snare is in a range of 0.1 to 0.

35.

7. The snare according to claim 4, characterized in that The ratio of the stiffness of the first connecting section to the stiffness of the second connecting section is in the range of 0.2 to 0.

9.

8. The snare according to claim 4, characterized in that The first connecting section and the second connecting section both include an arc-shaped structure, Wherein, the curvature of the arc-shaped structure of the first connecting segment is smaller than the curvature of the arc-shaped structure of the second connecting segment.

9. The snare according to claim 8, characterized in that The ratio of the curvature of the arc-shaped structure of the first connecting segment to the curvature of the arc-shaped structure of the second connecting segment is in a range of 0.1 to 0.

85.

10. The snare according to claim 4, characterized in that The hardness of the second connecting section is greater than the hardness of the first connecting section.

11. The snare according to claim 4, characterized in that The first characteristic size is smaller than the second characteristic size, The first characteristic dimension is a characteristic dimension of a cross section of the first connecting segment perpendicular to the axial direction of the first connecting segment, and the second characteristic dimension is a characteristic dimension of a cross section of the second connecting segment perpendicular to the axial direction of the second connecting segment.

12. The snare according to claim 11, characterized in that The ratio of the first characteristic size to the second characteristic size ranges from 0.5 to 0.

95.

13. The snare according to claim 4, characterized in that The first connecting section is composed of at least two first connecting units, and the second connecting section is composed of at least one second connecting unit. The first number of shares is greater than the second number of shares, The first number of strands is the number of strands of the first connection unit constituting the first connection segment, and the second number of strands is the number of strands of the second connection unit constituting the second connection segment.

14. The snare according to claim 13, characterized in that When the absolute value of the difference between the first characteristic size and the second characteristic size is less than or equal to a first preset threshold, the first number of strands is greater than the second number of strands; The first characteristic dimension is a characteristic dimension of a cross section of the first connecting segment perpendicular to the axial direction of the first connecting segment, and the second characteristic dimension is a characteristic dimension of a cross section of the second connecting segment perpendicular to the axial direction of the second connecting segment.

15. The snare according to claim 14, characterized in that The first preset threshold is any value between 0 and 0.1 mm.

16. The snare according to claim 4, characterized in that The second cross section is set to one or more of a circle, a square, and a hexagon, and the first cross section is set to one or more of a semicircle, a triangle, and a rectangle. The first cross section is a cross section of the first connecting segment perpendicular to the axial direction of the first connecting segment, and the second cross section is a cross section of the second connecting segment perpendicular to the axial direction of the second connecting segment.

17. The snare according to claim 4, characterized in that The second connecting section includes a basic connecting section and a stiffening member, and the stiffening member is fixed on the basic connecting section.

18. The snare according to claim 17, characterized in that The first connecting section and the basic connecting section are an integrated structure.

19. The snare according to any one of claims 4 to 18, characterized in that: The second rigid portion further includes a third connecting segment, which is located at the proximal end compared to the first connecting segment, the stiffness of the first connecting segment is smaller than the stiffness of the second connecting segment, and the stiffness of the first connecting segment is smaller than the stiffness of the third connecting segment.

20. The snare according to claim 19, characterized in that The two ports at the distal end of the first connection segment are respectively connected to the two ports at the proximal end of the second connection segment, the two ports at the proximal end of the first connection segment are respectively connected to the two ports at the distal end of the third connection segment, and the two ports at the proximal end of the third connection segment are connected to the operating part.

21. The snare according to claim 19, characterized in that When the snare portion does not enter the connecting portion, a ratio of a size of the third connecting section along the axial direction of the snare to a size of the snare portion along the axial direction of the snare is in a range of 1 / 10 to 2 / 5.

22. The snare according to claim 19, characterized in that The stiffness of the third connecting section is the same as the stiffness of the second connecting section; or The stiffness of the third connecting section is greater than the stiffness of the second connecting section; or The stiffness of the third connecting section is smaller than the stiffness of the second connecting section.

23. The snare according to claim 22, characterized in that When the stiffness of the third connecting segment is the same as the stiffness of the second connecting segment, the ratio of the stiffness of the first connecting segment to the stiffness of the second connecting segment is in the range of 0.2 to 0.9; or When the stiffness of the third connecting segment is greater than the stiffness of the second connecting segment, the ratio of the stiffness of the second connecting segment, the stiffness of the first connecting segment and the stiffness of the third connecting segment is in the range of (1.1-3.4):1:(1.4-3.6); or When the stiffness of the third connecting segment is less than the stiffness of the second connecting segment, the ratio of the stiffness of the second connecting segment, the stiffness of the first connecting segment and the stiffness of the third connecting segment is in the range of (1.1-3.5):1:(1-3.2).

24. The snare according to claim 19, characterized in that The hardness of the third connecting segment is greater than the hardness of the first connecting segment.

25. The snare according to claim 19, characterized in that The first characteristic size is smaller than the third characteristic size, The first characteristic dimension is a characteristic dimension of a cross section of the first connecting segment perpendicular to the axial direction of the first connecting segment, and the third characteristic dimension is a characteristic dimension of a cross section of the third connecting segment perpendicular to the axial direction of the third connecting segment.

26. The snare according to claim 25, characterized in that The ratio of the first characteristic size to the third characteristic size ranges from 0.5 to 0.

95.

27. The snare according to claim 19, characterized in that The first connecting section is composed of at least two first connecting units, and the third connecting section is composed of at least one third connecting unit. The first number of shares is greater than the third number of shares. The first number of strands is the number of strands of the first connection unit constituting the first connection segment, and the third number of strands is the number of strands of the third connection unit constituting the third connection segment.

28. The snare according to claim 27, characterized in that When the absolute value of the difference between the first characteristic size and the third characteristic size is less than or equal to the second preset threshold, the first number of strands is greater than the third number of strands. The first characteristic dimension is a characteristic dimension of a cross section of the first connecting segment perpendicular to the axial direction of the first connecting segment, and the third characteristic dimension is a characteristic dimension of a cross section of the third connecting segment perpendicular to the axial direction of the third connecting segment.

29. The snare according to claim 28, characterized in that The second preset threshold is any value between 0 and 0.1 mm.

30. The snare according to claim 19, wherein: The third cross section is set to one or more of a circle, a square, and a hexagon, and the first cross section is set to one or more of a semicircle, a triangle, and a rectangle. The first cross section is a cross section of the first connecting segment perpendicular to the axial direction of the first connecting segment, and the third cross section is a cross section of the third connecting segment perpendicular to the axial direction of the third connecting segment.

31. The snare according to claim 19, wherein: The third connecting section includes a basic connecting section and a stiffening member, and the stiffening member is fixed on the basic connecting section.

32. The snare according to claim 1, wherein: The snare portion is a symmetrical structure with the axis of the snare being the symmetry axis, and / or the second rigid portion is a symmetrical structure with the axis of the snare being the symmetry axis.

33. The snare according to claim 1, characterized in that The connecting part includes a first pulling member and a sheath tube, wherein the first pulling member is disposed in the sheath tube, and the first pulling member connects the snare part and the operating part; The operating part drives part or all of the snare part to extend out of or enter into the sheath tube through the first pulling member.

34. The snare according to claim 33, characterized in that At least a portion of the one of the first rigid portion and the second rigid portion that is closer to the first traction member is an integral structure with the first traction member; and / or At least a portion of the one of the first rigid portion and the second rigid portion that is closer to the first pulling member is fixedly connected to the first pulling member.

35. The snare according to claim 33, characterized in that The snare part includes a base part and an adjusting part, the adjusting part is slidably connected to the base part, two ports at the proximal end of the base part are connected to the distal end of the first traction member, and the adjusting part includes the first rigid part and the second rigid part. The operating part drives part or all of the base part and part or all of the adjustment part to extend out of or enter the sheath tube.

36. The snare of claim 35, wherein the connecting portion further comprises a second traction member, the second traction member is disposed in the sheath tube, the second traction member and the first traction member are both configured to be able to move along the axial direction of the sheath tube, and the second traction member can slide relative to the first traction member; The second traction member includes a first traction rope and a second traction rope, wherein a port at a distal end of the first traction rope is connected to a port at a proximal end of the adjustment portion, and a port at a distal end of the second traction rope is connected to another port at a proximal end of the adjustment portion. The first traction cable and the second traction cable slide along the axial direction of the sheath tube, driving the adjustment part to slide relative to the base part.

37. The snare according to claim 33, characterized in that The operating part comprises an adjusting member, and the adjusting member is connected to two ports at the proximal end of the snare part through the first traction member, and the adjusting member drives the two ports at the proximal end of the snare part to move synchronously or asynchronously.

38. The snare according to claim 1, wherein: The first rigid portion and / or the second rigid portion are configured with markings.

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