A snare

Abstract

This specification provides a snare, comprising: an operating part including a handle and a sliding member, the sliding member being slidable relative to the handle; a connecting part including a traction member and a sheath, the proximal end of the traction member being connected to the sliding member, the traction member being disposed within the sheath; and a snare part including a first connecting segment, a second connecting segment, and a third connecting segment, wherein two ports at the proximal end of the second connecting segment are respectively connected to two ports at the distal end of the first connecting segment, and two ports at the distal end of the second connecting segment are respectively connected to two ports at the proximal end of the third connecting segment; the proximal end of the first connecting segment is connected to the traction member; the sliding member slides to cause part or all of the snare part to extend or enter the sheath; the stiffness of the second connecting segment is less than the stiffness of the first connecting segment, and the stiffness of the second connecting segment is less than the stiffness of the third connecting segment.

Description

[0001] Priority Explanation

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

[0003] This manual relates to the field of medical devices, and in particular to a snare device. Background Technology

[0004] The snare is a commonly used medical device in modern medicine. It removes lesions by contracting the snare. However, during the retrieval of tissue, the axial change of the snare is smaller than its radial change when it retracts into the sheath. This causes the originally ring-shaped snare to gradually become a thin, elongated snare. Consequently, the tissue cannot be completely enclosed by the thin, elongated snare, resulting in the snare failing to gradually tighten and fix the tissue, thus affecting the integrity of the lesion resection.

[0005] Therefore, it is desirable to propose a snare device that can ensure stable morphological changes when the snare is retracted into the sheath, avoid the formation of long and thin snares, facilitate fixation of lesions, and make it easier to snare and adhere to the lesions, thereby ensuring complete resection of the lesions. Summary of the Invention

[0006] One embodiment of this specification provides a snare, comprising: an operating part including a handle and a sliding member, the sliding member being slidable relative to the handle; a connecting part including a traction member and a sheath, the proximal end of the traction member being connected to the sliding member, the traction member being disposed within the sheath; and a snare part including a first connecting segment, a second connecting segment, and a third connecting segment, wherein the distances of the first connecting segment, the second connecting segment, and the third connecting segment from the operating part increase sequentially, two ports at the proximal end of the second connecting segment are respectively connected to two ports at the distal end of the first connecting segment, two ports at the distal end of the second connecting segment are respectively connected to two ports at the proximal end of the third connecting segment, the proximal end of the first connecting segment is connected to the traction member, the sliding member slidably drives part or all of the snare part to extend or enter the sheath, the stiffness of the second connecting segment is less than the stiffness of the first connecting segment, and the stiffness of the second connecting segment is less than the stiffness of the third connecting segment.

[0007] In some embodiments, the stiffness of the first connecting segment is the same as the stiffness of the third connecting segment.

[0008] In some embodiments, the stiffness of the first connecting segment is greater than the stiffness of the third connecting segment.

[0009] In some embodiments, the stiffness of the first connecting segment is less than the stiffness of the third connecting segment.

[0010] In some embodiments, the first connecting segment and the traction member are an integral structure.

[0011] In some embodiments, the first connecting segment is fixedly connected to the traction member.

[0012] In some embodiments, when the snare portion is completely outside the sheath, the dimension of the third connecting segment along the axial direction of the snare is not less than one-eighth of the dimension of the snare portion along the axial direction of the snare, and not greater than one-quarter of the length of the snare portion along the axial direction of the snare.

[0013] In some embodiments, when at least a portion of the snare enters the sheath, the ratio of the radial dimension of the snare portion along the snare to the axial dimension of the snare portion along the snare is not less than 0.5 and not greater than 1.

[0014] In some embodiments, when at least a portion of the snare enters the sheath, a first rate of change of the snare portion is not greater than a second rate of change, wherein the first rate of change represents the ratio of the change in the size of the snare portion along the radial direction of the snare to its initial radial size, and the second rate of change represents the ratio of the change in the size of the snare portion along the axial direction of the snare to its initial axial size.

[0015] In some embodiments, the hardness of the first connecting segment and / or the third connecting segment is greater than the hardness of the second connecting segment; and / or the characteristic dimension of the cross section of the second connecting segment perpendicular to the axial direction of the second connecting segment is smaller than the characteristic dimension of the cross section of the first connecting segment perpendicular to the axial direction of the first connecting segment and / or the characteristic dimension of the cross section of the third connecting segment perpendicular to the axial direction of the third connecting segment.

[0016] In some embodiments, the first connecting segment is composed of at least one first connecting unit, the second connecting segment is composed of at least two second connecting units, and the third connecting segment is composed of at least one third connecting unit. The number of second connecting units constituting the second connecting segment is greater than the number of first connecting units constituting the first connecting segment and / or the number of third connecting units constituting the third connecting segment.

[0017] In some embodiments, the cross section of the first connecting segment perpendicular to the axial direction of the first connecting segment and / or the cross section of the third connecting segment perpendicular to the axial direction of the third connecting segment is set to one or more of a circle, a square, and a hexagon, and the cross section of the second connecting segment perpendicular to the axial direction of the second connecting segment is set to one or more of a semicircle, a triangle, and a rectangle.

[0018] In some embodiments, the first connecting segment and / or the third connecting segment includes a base connecting segment and a stiffening member, the stiffening member being fixed to the base connecting segment.

[0019] In some embodiments, the second connecting segment and the basic connecting segment are an integral structure. Attached Figure Description

[0020] This specification will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting; in these embodiments, the same reference numerals denote the same structures, wherein:

[0021] Figure 1 These are schematic diagrams of snares according to some embodiments of this specification;

[0022] Figure 2A This is a schematic diagram illustrating the use of a snare device.

[0023] Figure 2B These are schematic diagrams illustrating the use of the snare according to some embodiments of this specification;

[0024] Figure 3A This is another schematic diagram of the use of a certain snare;

[0025] Figure 3B This is yet another schematic diagram of the snare shown in some embodiments of this specification;

[0026] Figure 4 This is a schematic diagram of the snare portion shown according to some embodiments of this specification;

[0027] Figure 5 This is a schematic diagram illustrating the changes that occur during the operation of the snare section according to some embodiments of this specification;

[0028] Figure 6 This is a schematic diagram of the cross-section of the third connecting segment according to some embodiments of this specification;

[0029] Figure 7 This is a schematic diagram of another loop portion shown according to some embodiments of this specification;

[0030] Figure 8 This is a schematic diagram of another loop portion shown according to some embodiments of this specification;

[0031] Figure 9 This is a schematic diagram of a method for testing material stiffness according to some embodiments of this specification.

[0032] Reference numerals: 100, snare; 110, operating part; 111, handle; 112, sliding part; 120, connecting part; 121, sheath; 122, traction element; 123, connecting tube; 124, supporting protective tube; 125, connecting element; 130, snare part; 131, first connecting section; 131-a, first connecting unit; 132, second connecting section; 132-1, sub-connecting section; 133, third connecting section; 133-1, basic connecting section; 133-2, stiffening reinforcement; 134, guiding structure; 200, lesion; 310, material; 320, deformed material; 330, support element; 340, force application element. Detailed Implementation

[0033] To more clearly illustrate the technical solutions of the embodiments in this specification, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this specification. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0034] It should be understood that the terms “system,” “device,” “unit,” and / or “module” used herein are one way to distinguish different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0035] As indicated in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0036] Flowcharts are used in this specification to illustrate the operations performed by the system according to embodiments of this specification. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the steps can be processed in reverse order or simultaneously. Furthermore, other operations can be added to these processes, or one or more steps can be removed from them.

[0037] In some snare designs, the snare assembly becomes elongated as the snare tightens during operation. For example, the dimensional changes of the snare are shown in the table below.

[0038] stage Radial dimension (mm) Axial dimension (mm) Aspect Ratio initial stage 27 42 0.64 Phase 1 20 41 0.49 Phase Two 15 38 0.39 Phase Three 10 28 0.36

[0039] The initial stage to the third stage is a process of the snare gradually tightening, and the aforementioned axial dimension is the snare along the... Figure 1 The maximum axial dimension A of the snare 100 shown, the aforementioned radial dimension being the snare along the axial direction as shown... Figure 1 The maximum radial dimension B of the snare 100 shown. For example, when the snare is as follows... Figure 1 When the elliptical snare is shown, the axial dimension of the snare is the dimension corresponding to the major axis along axial direction A, and the radial dimension is the dimension corresponding to the minor axis along radial direction B.

[0040] As shown in the table above, the diameter-to-length ratio of the snare continuously decreases as it extends into the sheath, causing the snare to gradually become elongated and thinner, preventing the lesion from being completely enclosed by the elongated snare. Some embodiments of this specification use multiple connecting segments with varying stiffnesses for the snare, with the distance from the operating part increasing sequentially for the first, second, and third connecting segments. The stiffness of the second connecting segment is less than that of the first, and the stiffness of the third connecting segment is less than that of the first. This arrangement allows the first connecting segment, with its higher stiffness, to easily capture and adhere to the lesion during operation. Simultaneously, the varying stiffness of each connecting segment results in different deformations, ensuring the stability of the snare's shape and preventing it from becoming elongated and thinner, thus guaranteeing the integrity of the snare's coverage of the lesion and improving the efficiency and completeness of the cutting process.

[0041] It is worth noting that the stiffness of the first, second, and third connecting sections described in this specification can be determined by various methods. For example, tensile testing, compression testing, bending testing, and torsion testing. Furthermore, it can also be determined by... Figure 9 The method shown is used to test and determine the stiffness of the first, second, and third connecting sections. For example... Figure 9 As shown, a material 310 can be placed on a support 330. A force-applying component 340 can apply a vertically downward force F toward the center of the material 310. The material 310 deforms under the action of the force F to obtain a deformed material 320. The magnitude of the deformation of the material 310 and the deformed material 320 along the direction of the force F is the displacement H. The stiffness K of the aforementioned material 310 can be calculated using the formula K = F / H.

[0042] Figure 1 This is a schematic diagram of a snare according to some embodiments of this specification.

[0043] The snare 100 can be used to remove lesions (e.g., polyps). Figure 1 As shown, the snare 100 may include an operation part 110, a connecting part 120, and a snare part 130.

[0044] The operating unit 110 can be used by an operator (e.g., a doctor using the snare 100) to control the snare 100. Figure 1 As shown, the operating unit 110 may include a handle 111 and a slider 112, which can slide relative to the handle 111. When using the snare 100, the operator can insert their finger into the limiting hole of the slider 112 and apply a force along the axial direction A of the snare 100 to the slider 112, so that the slider 112 can slide relative to the handle 111 along the axial direction A.

[0045] The connecting part 120 can be used to connect the operating part 110 and the snare part 130. For example... Figure 1 As shown, the connecting part 120 may include a sheath 121 and a traction member 122. The proximal end of the traction member 122 is connected to the sliding member 112, and the traction member 122 may be disposed inside the sheath 121. The aforementioned traction member 122 may be a traction rope. It is worth noting that, as Figure 1 As shown, the distal end of each component in this specification is the end further away from the operating part 110 of the snare 100, and the proximal end is the end closer to the operating part 110 of the snare 100.

[0046] In some embodiments, the connecting portion 120 may also include other structures. For example... Figure 1 As shown, the connecting part 120 may further include a connecting tube 123, the proximal end of which is connected to the distal end of the traction member 122, and the distal end of which is connected to the first connecting section 131. The connecting tube 123 may be disposed inside or outside the sheath tube 121. The connecting part 120 may also include a supporting protective tube 124. The supporting protective tube 124 may be disposed outside the sheath tube 121. It is understood that the sheath tube 121 may be made of a flexible material, and the supporting protective tube 124 may support the sheath tube 121 to ensure the normal use of the snare 100. The connecting part 120 may also include a connector 125, through which the sheath tube 121 can be connected to the operating part 110.

[0047] The snare portion 130 can be used to remove a specific area from a patient. The snare portion 130 can be a ring-shaped structure. For example, the shape of the snare portion 130 can be a circular ring structure, an elliptical ring structure, a hexagonal ring structure, etc.

[0048] like Figure 1As shown, the snare portion 130 may include a first connecting segment 131, a second connecting segment 132, and a third connecting segment 133, wherein the distances between the first connecting segment 131, the second connecting segment 132, and the third connecting segment 133 and the operating portion 110 increase sequentially. The first connecting segment 131, the second connecting segment 132, and the third connecting segment 133 may be formed of various biocompatible materials. For example, the first connecting segment 131, the second connecting segment 132, and the third connecting segment 133 may include, but are not limited to, metals, polymers, alloys, etc. Furthermore, the first connecting segment 131, the second connecting segment 132, and the third connecting segment 133 may include steel, tungsten, nickel-titanium 6, or titanium, etc.

[0049] like Figure 1 As shown, the two ports near the end of the second connection segment 132 are respectively connected to the two ports far from the end of the first connection segment 131, and the two ports far from the end of the second connection segment 132 are respectively connected to the two ports near the end of the third connection segment 133. In some embodiments, the second connection segment 132 may include two sub-connection segments. For example... Figure 1 As shown, the second connection segment 132 may further include two sub-connection segments 132-1. The near end and far end ports of the sub-connection segment 132-1 are respectively connected to a port at the far end of the first connection segment 131 and a port at the near end of the third connection segment 133. The near end and far end ports of the other sub-connection segment 132-1 are respectively connected to another port at the far end of the first connection segment 131 and another port at the near end of the third connection segment 133.

[0050] In some embodiments, the first connecting segment 131, the second connecting segment 132, and the third connecting segment 133 can be an integral structure or a non-integral structure. Further explanation regarding the integral structure of the first connecting segment 131, the second connecting segment 132, and the third connecting segment 133 can be found in [reference needed]. Figure 7 , Figure 8 And related explanations. When the first connecting segment 131, the second connecting segment 132, and the third connecting segment 133 are not integral structures, they can be connected by various connection processes. The aforementioned connection processes may include, but are not limited to, one or more of laser welding, brazing, plasma welding, argon arc welding, and turning forging. Preferably, the first connecting segment 131, the second connecting segment 132, and the third connecting segment 133 can be connected by one or more of laser welding, brazing, and turning forging, thereby increasing the rigidity of the connection between the first connecting segment 131 and the second connecting segment 132, and between the third connecting segment 133 and the second connecting segment 132, preventing the snare portion 130 from becoming slender during operation, and ensuring proper fit and capture of the lesion.

[0051] In some embodiments, the proximal end of the first connecting segment 131 can be connected to the traction member 122. In some optional embodiments, the proximal end of the first connecting segment 131 and the traction member 122 can be an integral structure. This configuration simplifies the production process of the first connecting segment 131 and the traction member 122, ensures the stability of the connection between the first connecting segment 131 and the traction member 122, and prevents the first connecting segment 131 from detaching. In other embodiments, the proximal end of the first connecting segment 131 can be fixedly connected to the traction member 122. For example, the proximal end of the first connecting segment 131 can be fixedly connected to the traction member 122 by one or more of laser welding, brazing, and turning. Since the proximal end of the first connecting segment 131 can be connected to the traction member 122, and the traction member 122 is also connected to the sliding member 112, the sliding of the sliding member 112 can drive part or all of the snare portion 130 to extend or enter the sheath tube 121, thereby causing the snare portion 130 to deform.

[0052] In some embodiments, the stiffness of the second connecting segment 132 is less than the stiffness of the third connecting segment 133. For example, the stiffness of the second connecting segment 132 may be approximately 50–400 N / m, and the stiffness of the third connecting segment 133 may be approximately 200–1000 N / m. Preferably, the stiffness of the second connecting segment 132 may be 110 N / m, and the stiffness of the third connecting segment 133 may be 635 N / m. In some embodiments, the stiffness of the second connecting segment 132 may be less than the stiffness of the third connecting segment 133 through various settings. Further details on how to set the stiffness of the second connecting segment 132 to be less than the stiffness of the third connecting segment 133 can be found below in this description.

[0053] During the operation of the snare 100 shown in some embodiments of this specification, the size of the snare changes as it tightens, as shown in the table below.

[0054] stage Radial dimension (mm) Axial dimension (mm) Aspect Ratio initial stage 27 33.5 0.8 Phase 1 20 31 0.65 Phase Two 15 21 0.71 Phase Three 10 18 0.0.55

[0055] As can be seen from the table above, some embodiments of this specification, by setting the snare of the snare 100 as a second connecting segment 132 and a third connecting segment 133 with different stiffnesses, can make the snare shape change stable during the operation of the snare 100, prevent the snare portion 130 from gradually becoming thinner and longer, ensure the integrity of the snare portion 130 in wrapping the lesion, and improve the efficiency and integrity of cutting.

[0056] In some embodiments, the stiffness of the second connecting segment 132 is less than the stiffness of the first connecting segment 131. For example, the stiffness of the second connecting segment 132 can be approximately 50–400 N / m, and the stiffness of the first connecting segment 131 can be approximately 200–1000 N / m. Preferably, the stiffness of the second connecting segment 132 can be 110 N / m, and the stiffness of the first connecting segment 131 can be 635 N / m. Figure 2AAs shown, when the rigidity of the part connecting the snare portion to the connecting portion of the snare is low, the snare portion cannot apply force to the lesion 200, and cannot guarantee a good fit between the snare portion of the snare and the lesion 200. For example... Figure 2B As shown, when the rigidity of the first connecting segment 131 is large, the operator can adjust the direction and angle of the snare portion 130 when using the snare 100, so that the first connecting segment 131 can apply force to the lesion 200, thereby deforming the lesion 200 and allowing the snare portion 130 in the snare 100 to fit more tightly with the lesion 200. Some embodiments of this specification, by setting the first connecting segment 131 between the second connecting segment 132 and the connecting portion 120, can ensure the stability of the snare shape change during the operation of the snare 100, prevent the snare portion 130 from gradually becoming thinner and longer, and ensure that the snare portion 130 in the snare 100 fits more closely with the lesion 200, thereby improving the efficiency and integrity of the cutting.

[0057] In some embodiments, the stiffness of the second connecting segment 132 is less than the stiffness of the first connecting segment 131, and the stiffness of the second connecting segment 132 is less than the stiffness of the third connecting segment 133. For example, the stiffness of the first connecting segment 131 can be about 200 to 1000 N / m, the stiffness of the second connecting segment 132 can be about 50 to 400 N / m, and the stiffness of the third connecting segment 133 can be about 200 to 1000 N / m.

[0058] Understandably, when an operator uses a snare to trap a lesion, if the stiffness of the part connecting the snare to the connecting part is low, the snare will deform towards its center of gravity when it is in the air due to gravity, causing the radial distance of the snare to shorten. However, some embodiments of this specification, by providing a first connecting section 131 with higher stiffness between the second connecting section 132 and the connecting part 120, can reduce the deformation of the snare 130 in the air, preventing the radial distance of the snare from shortening and facilitating the snare 100 to trap the lesion.

[0059] In some embodiments, the stiffness of the first connecting segment 131 can be increased by increasing the curvature of the first connecting segment 131. For example, the curvature of the first connecting segment 131 can be approximately 50 to 150 μm. -1 Preferably, the curvature of the first connecting segment 131 can be 100m. -1 .like Figure 3A As shown, when the curvature of the part connecting the snare to the connecting part of the snare is small, it is difficult to snare larger lesions 200. For example... Figure 3BAs shown, the snare 100 can increase the stiffness of the first connecting segment 131 by increasing its curvature, thereby reducing its deformation in the air. It can also increase the radial opening B of the first connecting segment 131 to snare larger lesions 200. In some embodiments, the stiffness of the second connecting segment 132 can be made less than that of the first connecting segment 131 through various other settings. Further details on how to make the stiffness of the second connecting segment 132 less than that of the first connecting segment 131 can be found below in this description.

[0060] In some embodiments, the stiffness of the first connecting segment 131 and the stiffness of the third connecting segment 133 can be the same. For example, the stiffness of both the first connecting segment 131 and the third connecting segment 133 can be 635 N / m. By setting the stiffness of the first connecting segment 131 and the stiffness of the third connecting segment 133 to the same value, the snare 100 can change uniformly during use, making it easier for the operator to control the snare progress. When the snare 100 is used to snare polyps with uniform overall hardness, the stiffness of the first connecting segment 131 in the snare 100 can be equal to the stiffness of the third connecting segment 133, so that the snare portion 130 contacts and adheres to the entire polyp tissue.

[0061] In some embodiments, the stiffness of the first connecting segment 131 can be greater than the stiffness of the third connecting segment 133. For example, the stiffness of the first connecting segment 131 can be 635 N / m, and the stiffness of the third connecting segment 133 can be 390 N / m. By setting the stiffness of the first connecting segment 131 to be greater than the stiffness of the third connecting segment 133, the snare 100 can maintain its shape before snare formation, avoiding deformation and facilitating the snare of the lesion. When the snare 100 is used to snare a relatively hard proximal polyp tissue, the stiffness of the first connecting segment 131 in the snare 100 can be greater than the stiffness of the third connecting segment 133, so that the snare portion 130 makes stable contact with the proximal end of the polyp.

[0062] In some embodiments, the stiffness of the first connecting segment 131 can be less than the stiffness of the third connecting segment 133. For example, the stiffness of the first connecting segment 131 can be 390 N / m, and the stiffness of the third connecting segment 133 can be 635 N / m. By setting the stiffness of the first connecting segment 131 to be less than the stiffness of the third connecting segment 133, it is ensured that the operator can make cuts with less force. When the snare 100 is used to snare harder distal polyp tissue, the stiffness of the third connecting segment 133 in the snare 100 can be greater than the stiffness of the first connecting segment 131, so that the snare portion 130 makes stable contact with the distal end of the polyp.

[0063] In some embodiments, the snare portion 130 may further include other structures. For example, a guide structure 134 may also be provided on the snare portion 130. The aforementioned guide structure 134 can be used to guide and locate the lesion, and is in the shape of a "V". The aforementioned guide structure 134 can be positioned at the foremost end of the snare 100 along the axial direction A. Figure 1 As shown, the aforementioned guide structure 134 can be located at the far end of the third connecting segment 133.

[0064] In some embodiments, such as Figure 4 As shown, when the snare portion 130 is completely outside the sheath 121, the dimension c of the third connecting section 133 along the aforementioned axial direction A is not less than one-eighth of the dimension d of the snare portion 130 along the axial direction A, and not greater than one-quarter of the dimension d of the snare portion 130 along the axial direction A. It is worth noting that, on the one hand, when the ratio of dimension c to dimension b is less than one-eighth, even if a third connecting segment 133 with greater rigidity is provided, its size is too small, so the overall deformation of the snare portion 130 is less affected when the snare 100 is working, and the snare portion 130 will still become slender; on the other hand, when the ratio of dimension c to dimension b is greater than one-quarter, the size of the third connecting segment 133 with greater rigidity is too large, which may cause the snare portion 130 to not fit and fix well to the lesion. Moreover, when other smaller structures (such as the first connecting segment 131 and the second connecting segment 132) enter the sheath 121, since the snare portion only includes the third connecting segment, the snare portion 130 will still become slender during subsequent operation. Preferably, when the ratio of dimensions a, b, and c is 1:2:1, the loop portion 130 changes most stably and can fit well with the lesion, wherein dimensions a and b are the dimensions of the first connecting segment 131 and the second connecting segment 132 along the aforementioned axial direction A, respectively.

[0065] Some embodiments of this specification, by limiting the size of the third connecting segment 133, can ensure that the loop portion 130 does not gradually become thinner and longer, and can fit well with the lesion.

[0066] In some embodiments, such as Figure 5 As shown, when at least a portion of the snare portion 130 enters the sheath 121, the ratio of the dimension of the snare portion 130 along the radial direction B of the snare device 100 to the dimension of the snare portion along the axial direction A of the snare device 100 is not less than 0.5 and not greater than 1. The snare portion is the part of the snare portion 130 located outside the sheath 121. When the snare portion 130 is completely located outside the sheath 121, the snare portion can be the snare portion 130 itself. Figure 5As shown, during the tightening process of a certain snare portion 130, the snare portion located outside the sheath tube 121 can change from snare portion 130-a to snare portion 130-b and then to snare portion 130-c. Here, L1, L2, and L3 are the dimensions of snare portions 130-a, 130-b, and 130-c along the axial direction A, respectively, and D1, D2, and D3 are the dimensions of snare portions 130-a, 130-b, and 130-c along the radial direction B, respectively. During the tightening process of the snare portion 130, the ratios D1 / L1, D2 / L2, and D3 / L3 are always not less than 0.5 and not greater than 1. Preferably, the aforementioned ratios can be 0.7. In some embodiments of this specification, the aforementioned settings can prevent the sleeve portion 130 from gradually becoming elongated due to excessive axial A dimension or gradually flattening due to excessive radial B dimension during operation, thus ensuring the stability of the sleeve portion 130's changes.

[0067] In some embodiments, such as Figure 5 As shown, when at least a portion of the snare portion 130 enters the sheath 121, the first rate of change of the snare portion 130 is not 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 to the initial radial size, 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 to the initial axial size. The aforementioned initial radial size and initial axial size are the initial values ​​of the size of the snare portion 130 along the radial direction B and the axial direction A when the snare portion 130 is completely outside the sheath 121, respectively. In some embodiments, for any moment when the snare 100 is in operation, the following formula (1) is satisfied:

[0068]

[0069] Where D0 is the initial radial dimension of the snare portion 130, L0 is the initial axial dimension of the snare portion 130, and D i Let L be the dimension of the snare portion along the radial direction B of the snare at the current moment. i Let A be the dimension of the snare portion along the snare axis at the current moment.

[0070] Some embodiments of this specification, by limiting the first rate of change to no more than the second rate of change, can make the radial change of the snare portion 130 less than the axial change, so as to prevent the snare portion 130 from gradually becoming thinner and longer, which is beneficial for the snare and fixation of the lesion.

[0071] The following will explain how to configure the first connecting segment 131, the second connecting segment 132, and the third connecting segment 133 such that the stiffness of the second connecting segment 132 is less than the stiffness of the first connecting segment 131, and the stiffness of the second connecting segment 132 is less than the stiffness of the third connecting segment 133. It is understood that the snare 100 can ensure the stiffness difference between the first connecting segment 131, the second connecting segment 132, and the third connecting segment 133 based on one or more of the following configurations.

[0072] In some embodiments, the hardness of the first connecting segment 131 is greater than the hardness of the second connecting segment 132 to ensure that the stiffness of the second connecting segment 132 is less than the stiffness of the first connecting segment 131. For example, the hardness of the first connecting segment 131 and the hardness of the second connecting segment 132 can differ by 5 to 10 HRB, with the hardness of the first connecting segment 131 being approximately 85 to 90 HRB and the hardness of the second connecting segment 132 being approximately 75 to 80 HRB. Similarly, the hardness of the third connecting segment 133 can be greater than the hardness of the second connecting segment 132 to ensure the stiffness of the third connecting segment 133 is equal to the stiffness of the second connecting segment 132.

[0073] In some embodiments, the first connecting segment 131, the second connecting segment 132, and the third connecting segment 133 may be made of different materials. When selecting materials, the hardness of the second connecting segment 132 should be less than that of the first connecting segment 131 and / or the third connecting segment 133. In some embodiments, the first connecting segment 131, the second connecting segment 132, and the third connecting segment 133 may also be made of the same material. When the first connecting segment 131, the second connecting segment 132, and the third connecting segment 133 are made of the same material, the hardness of the first connecting segment 131 and / or the third connecting segment 133 can be increased through hardening processes (such as heat treatment, work hardening, alloying, grain refinement, etc.).

[0074] In some embodiments, the characteristic dimension of the cross-section of the second connecting segment 132 perpendicular to its axial direction can be smaller than the characteristic dimension of the cross-section of the third connecting segment 133 perpendicular to its axial direction, so as to improve the stiffness of the second connecting segment 132 and the stiffness of the third connecting segment 133. The characteristic dimension can be the smallest dimension reflecting the shape characteristics of the cross-section. For example, when the cross-section is elliptical, the dimension reflecting the characteristics of the interface can include the major axis and the minor axis, and the characteristic dimension can be the minor axis. As another example, when the cross-section is rectangular, the dimension reflecting the characteristics of the interface can include the length and the width, and the characteristic dimension can be the smaller of the length and the width. As yet another example, when the cross-section is circular, the dimension reflecting the characteristics of the interface can include the diameter, and the characteristic dimension can be the diameter. As yet another example, when the cross-section is triangular, the dimension reflecting the characteristics of the interface can include the height and the base, and the characteristic dimension can be the smaller of the height and the base. Similarly, the characteristic dimension of the cross section of the second connecting segment 132 perpendicular to the axial direction of the second connecting segment 132 can be smaller than the characteristic dimension of the cross section of the first connecting segment 131 perpendicular to the axial direction of the first connecting segment 131, so that the stiffness of the second connecting segment 132 is less than the stiffness of the first connecting segment 131.

[0075] In some embodiments, the feature sizes of the first connecting segment 131, the second connecting segment 132, and the third connecting segment 133 can be of the same type. For example... Figure 4 As shown, the feature dimension of the cross section NN of the second connecting segment 132 perpendicular to its axial direction is smaller than the feature dimension of the cross section OO of the first connecting segment 131 perpendicular to its axial direction and the feature dimension of the cross section MM of the third connecting segment 133 perpendicular to its axial direction. For example, when the cross section OO of the first connecting segment 131, the cross section NN of the second connecting segment 132, and the cross section MM of the third connecting segment 133 are all circular, the aforementioned feature dimensions can be the diameters of the cross sections OO, NN, and MM, and the diameters of the cross sections OO and MM should be larger than the diameter of the cross section NN. In some embodiments, the difference between the feature dimensions of the cross sections OO and MM and the cross section NN can be 0.1 to 0.2 mm. For example, the feature dimensions of the cross sections NN, OO, and MM can be 0.30 mm, 0.40 mm, and 0.40 mm, respectively.

[0076] In some embodiments, the feature dimensions of the first connecting segment 131, the second connecting segment 132, and the third connecting segment 133 may also be of different types. For example, if the cross-section corresponding to the first connecting segment 131 is circular, then the feature dimension corresponding to the first connecting segment 131 is the diameter of the aforementioned circular cross-section; if the cross-section corresponding to the second connecting segment 132 is elliptical, then the feature dimension corresponding to the second connecting segment 132 is the minor axis of the aforementioned elliptical cross-section.

[0077] In some embodiments, the first connecting segment 131 is composed of at least one first connecting unit 131-a, the second connecting segment 132 is composed of at least two second connecting units, and the third connecting segment 133 is composed of at least one third connecting unit. The first connecting unit 131-a, the second connecting unit, and the third connecting unit can be the smallest units constituting the first connecting segment 131, the second connecting segment 132, and the third connecting segment 133, respectively. It is understood that the first connecting segment 131, the second connecting segment 132, and the third connecting segment 133 are strip-shaped structures, and correspondingly, the first connecting unit 131-a, the second connecting unit, and the third connecting unit can also be strip-shaped structures.

[0078] In some embodiments, multiple strands of first connecting units 131-a can be merged using various merging processes to form a corresponding first connecting segment 131. On any cross-section of the first connecting segment 131 perpendicular to its axis, each strand of the first connecting unit 131-a can be seen. For example... Figure 6 As shown, a certain first connecting segment 131 can be composed of seven first connecting units 131-a. The 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 first connecting units 131-a can be arranged and deformed by rotation, thereby fixing the multiple first connecting units 131-a to form the first connecting segment 131. As another example, multiple first connecting units 131-a can also be connected and fixed by welding, gluing, etc., to form the first connecting segment 131. Similarly, multiple second and third connecting units can also be combined using the aforementioned various merging processes to form the corresponding second connecting segment 132 and third connecting segment 133.

[0079] In some embodiments, the number of shares of the second connecting unit constituting the second connecting segment 132 is greater than the number of shares of the first connecting unit 131-a constituting the first connecting segment 131. For example, the number of shares of the second connecting unit constituting the second connecting segment 132 is 20, and the number of shares of the first connecting unit 131-a constituting the first connecting segment 131 is 10. Similarly, the number of shares of the second connecting unit constituting the second connecting segment 132 may also be greater than the number of shares of the third connecting unit constituting the third connecting segment 133.

[0080] In some embodiments, the cross-section of the first connecting segment 131 perpendicular to its axial direction and / or the cross-section of the third connecting segment 133 perpendicular to its axial direction can be one or more of a circle, a square, and a hexagon, and the cross-section of the second connecting segment 132 perpendicular to its axial direction can be one or more of a semicircle, a triangle, and a rectangle. It is worth noting that since circular, square, and hexagonal cross-sectional shapes have a more uniform dimensional distribution in all directions compared to semicircular, triangular, and rectangular cross-sectional shapes, structures with circular, square, or hexagonal cross-sections can have greater stiffness than structures with semicircular, triangular, or rectangular cross-sections. By setting different cross-sectional shapes for the first connecting segment 131, the second connecting segment 132, and the third connecting segment 133, differences in stiffness can be achieved among them.

[0081] In some embodiments, the first connecting segment 131 and / or the third connecting segment 133 may include a base connecting segment and a stiffening reinforcement, the stiffening reinforcement being fixed to the base connecting segment. For example... Figure 7 As shown, the third connecting segment 133 may include a basic connecting segment 133-1 and a stiffening reinforcement 133-2, wherein the stiffening reinforcement 133-2 may be spirally wound around the basic connecting segment 133-1, thereby increasing the stiffness of the third connecting segment 133. Figure 8 As shown, the third connecting segment 133 may include a basic connecting segment 133-1 and a stiffening reinforcement 133-2. The stiffening reinforcement 133-2 may be a tubular material sleeved outside the basic connecting segment 133-1. The aforementioned 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 reinforcement may also include a medical coating disposed outside the basic connecting segment, which may increase the stiffness of the third connecting segment 133.

[0082] In some embodiments, the stiffness of the stiffening member can be greater than the stiffness of the second connecting segment 132. For example, the stiffening member can be, but is not limited to, materials with stiffness greater than that of the second connecting segment 132, such as nickel-titanium, titanium alloy, or stainless steel. Some embodiments of this specification, by separately providing the basic connecting segment and the stiffening member, facilitate the adjustment of the structure, material, etc., of the stiffening member, thereby allowing for convenient adjustment of the stiffness of the first connecting segment 131 and / or the third connecting segment 133 as needed.

[0083] In some embodiments, the first connecting segment 131 and / or the third connecting segment 133, which consists of a base connecting segment and a stiffening reinforcement, can be connected to the second connecting segment 132 in various ways. For example, the base connecting segment and the stiffening reinforcement can be combined, and the two distal ports of the second connecting segment 132 can be connected to the two distal ports of the combined base connecting segment and the stiffening reinforcement in the third connecting segment 133 through various connection processes (e.g., welding, adhesive bonding).

[0084] In some embodiments, the second connecting segment 132 and the basic connecting segment can also be an integral structure. For example... Figure 7 as well as Figure 8 As shown, the second connecting section 132 and the basic connecting section 133-1 can be an integral structure. The materials and cross-sectional dimensions of the second connecting section 132 and the basic connecting section can be the same, and they can be obtained through integral molding to reduce production costs. In addition, the user of the snare 100 can flexibly choose the position of the rigidity reinforcement according to actual needs (e.g., the shape of the lesion) so that the snare 130 can fit more closely to the lesion when in use.

[0085] Some embodiments of this specification can modify existing snares by making the second connecting section 132 and the basic connecting section into an integrated structure. This allows for the addition of stiffness reinforcements as needed, preventing the snare section 130 from becoming slender during use, and also reducing the production cost of the improved snare 100.

[0086] The basic concepts have been described above. Obviously, for those skilled in the art, the detailed disclosure above is merely illustrative and does not constitute a limitation of this specification. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this specification. Such modifications, improvements, and corrections are suggested in this specification and therefore remain within the spirit and scope of the exemplary embodiments described herein.

[0087] Furthermore, this specification uses specific terms to describe embodiments thereof. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "an embodiment," "one embodiment," or "an alternative embodiment" in different locations throughout this specification do not necessarily refer to the same embodiment. Moreover, certain features, structures, or characteristics in one or more embodiments of this specification can be appropriately combined.

[0088] Furthermore, unless expressly stated in the claims, the order of processing elements and sequences, the use of numbers and letters, or other names described in this specification are not intended to limit the order of the processes and methods described herein. Although various examples have been discussed in the foregoing disclosure of some embodiments of the invention that are currently considered useful, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments; rather, the claims are intended to cover all modifications and equivalent combinations that conform to the spirit and scope of the embodiments described herein. For example, while the system components described above can be implemented using hardware devices, they can also be implemented solely using software solutions, such as installing the described system on existing servers or mobile devices.

[0089] Similarly, it should be noted that, in order to simplify the description disclosed herein and thus aid in the understanding of one or more embodiments of the invention, the foregoing description of embodiments in this specification may sometimes combine multiple features into a single embodiment, drawing, or description thereof. However, this method of disclosure does not imply that the subject matter of this specification requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of a single embodiment disclosed above.

[0090] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of range in some embodiments of this specification are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

[0091] For each patent, patent application, patent application publication, and other material, such as articles, books, specifications, publications, and documents, referenced in this specification, the entire contents of which are incorporated herein by reference. This excludes historical application documents that are inconsistent with or conflict with the content of this specification, as well as documents that limit the broadest scope of the claims in this specification (currently or subsequently appended to this specification). It should be noted that in the event of any inconsistency or conflict between the descriptions, definitions, and / or terminology used in the supplementary materials to this specification and the content of this specification, the descriptions, definitions, and / or terminology used in this specification shall prevail.

[0092] Finally, it should be understood that the embodiments described in this specification are merely illustrative of the principles of the embodiments described herein. Other variations may also fall within the scope of this specification. Therefore, alternative configurations of the embodiments described herein are intended to be illustrative rather than limiting, and should be considered consistent with the teachings of this specification. Accordingly, the embodiments described herein are not limited to those explicitly introduced and described herein.

Claims

1. A snare device, characterized in that, include: The operating unit includes a handle and a slider, the slider being slidable relative to the handle; The connecting part includes a traction member and a sheath tube, wherein the proximal end of the traction member is connected to the sliding member, and the traction member is disposed inside the sheath tube; The snare section includes a first connecting segment, a second connecting segment, and a third connecting segment, wherein the distances between the first connecting segment, the second connecting segment, and the third connecting segment and the operating unit increase sequentially. The two ports at the near end of the second connecting segment are respectively connected to the two ports at the far end of the first connecting segment, and the two ports at the far end of the second connecting segment are respectively connected to the two ports at the near end of the third connecting segment. The proximal end of the first connecting segment is connected to the traction member, and the sliding member slides to cause part or all of the loop portion to extend or enter the sheath. The stiffness of the second connecting segment is less than that of the first connecting segment, and the stiffness of the second connecting segment is less than that of the third connecting segment.

2. The snare device as described in claim 1, characterized in that, The stiffness of the first connecting segment is the same as that of the third connecting segment.

3. The snare device as described in claim 1, characterized in that, The stiffness of the first connecting segment is greater than the stiffness of the third connecting segment; or The stiffness of the first connecting segment is less than the stiffness of the third connecting segment.

4. The snare device as described in claim 1, characterized in that, The first connecting section and the traction component are an integral structure.

5. The snare device as described in claim 1, characterized in that, The first connecting segment is fixedly connected to the traction component.

6. The snare device as described in claim 1, characterized in that, When the snare is completely outside the sheath, the dimension of the third connecting section along the axial direction of the snare is not less than one-eighth of the dimension of the snare along the axial direction of the snare, and not greater than one-quarter of the dimension of the snare along the axial direction of the snare.

7. The snare device as described in claim 1, characterized in that, When at least a portion of the snare enters the sheath, the ratio of the radial dimension of the snare portion along the snare to the axial dimension of the snare portion along the snare is not less than 0.5 and not greater than 1.

8. The snare device as described in claim 1, characterized in that, When at least a portion of the snare enters the sheath, a first rate of change of the snare portion is not greater than a second rate of change, wherein the first rate of change represents the ratio of the change in the size of the snare portion along the radial direction of the snare to its initial radial size, and the second rate of change represents the ratio of the change in the size of the snare portion along the axial direction of the snare to its initial axial size.

9. The snare device as described in any one of claims 1 to 8, characterized in that, The hardness of the first connecting segment and / or the third connecting segment is greater than the hardness of the second connecting segment; and / or The characteristic dimension of the cross section of the second connecting segment perpendicular to the axial direction of the second connecting segment is smaller than the characteristic dimension of the cross section of the first connecting segment perpendicular to the axial direction of the first connecting segment and / or the characteristic dimension of the cross section of the third connecting segment perpendicular to the axial direction of the third connecting segment.

10. The snare device as described in any one of claims 1 to 8, characterized in that, The first connecting segment consists of at least one first connecting unit, the second connecting segment consists of at least two second connecting units, and the third connecting segment consists of at least one third connecting unit. The number of strands of the second connecting unit constituting the second connecting segment is greater than the number of strands of the first connecting unit constituting the first connecting segment and / or the number of strands of the third connecting unit constituting the third connecting segment.

11. The snare device as described in any one of claims 1 to 8, characterized in that, The cross section of the first connecting segment perpendicular to the axial direction of the first connecting segment and / or the cross section of the third connecting segment perpendicular to the axial direction of the third connecting segment is set to one of a circle, a square, or a hexagon, and the cross section of the second connecting segment perpendicular to the axial direction of the second connecting segment is set to one of a semicircle, a triangle, or a rectangle.

12. The snare device as described in any one of claims 1 to 8, characterized in that, The first connecting segment and / or the third connecting segment includes a basic connecting segment and a stiffening member, the stiffening member being fixed to the basic connecting segment.

13. The snare as described in claim 12, characterized in that, The second connecting segment and the basic connecting segment are an integral structure.

14. The snare as described in claim 1, characterized in that, The curvature of the first connecting segment is greater than the curvature of the second connecting segment.

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