A passive bending section of an endoscope and an endoscope

Abstract

This invention provides a passive bending section for an endoscope and an endoscope itself. The passive bending section is disposed at the insertion portion of the endoscope, which inserts the subject from the front end along its length axis. The passive bending section includes a snake-bone assembly comprising multiple sequentially hinged snake-bone segments. It also includes a woven mesh, which is fitted over the outer peripheral surface of the snake-bone assembly and comprises multiple sequentially connected woven mesh units. When each woven mesh unit bends to its maximum bending angle, the passive bending section reaches its maximum bending angle. By fitting a woven mesh over the outer peripheral surface of the snake-bone assembly, and ensuring that the passive bending section reaches its maximum bending angle when each woven mesh unit bends to its maximum bending angle, while maintaining a gap between adjacent snake-bone segments, the woven mesh exhibits elasticity and does not become interlocked between adjacent snake-bone segments at the maximum bending angle, thus improving its performance and extending its service life.

Description

Technical Field

[0001] This invention relates to the field of endoscopy technology, and more particularly to a passive bending section of an endoscope and an endoscope. Background Technology

[0002] Medical endoscopes, especially flexible endoscopes, are important instruments that can be inserted into human cavities for direct examination and surgical treatment, and are a common method for visualizing the internal cavities of the human body. Flexible endoscopes typically have a passive bending section added between the active bending section and the flexible section, which allows the endoscope to have a wider range of bending angles, eliminates blind spots, and makes endoscopic examination and treatment easier.

[0003] The passive bending section is primarily used to adapt to the shape of a body cavity and reduce patient discomfort during insertion. It bends passively under external force. When the endoscope is inserted into the cavity, the passive bending section naturally bends according to the cavity's shape to adapt to its curvature. The passive bending section consists of multiple sequentially connected serpentine segments, which are joined together using snap-fit, riveting, or other techniques to form a serpentine assembly. In existing passive bending sections, the maximum bending is achieved by adjacent segments abutting against each other. When adjacent segments abut, a smooth transition cannot be achieved, resulting in an uneven bending of the entire passive bending section within the body cavity. This makes some lesions difficult to observe, increases patient pain, and prolongs surgical time. Furthermore, the metal mesh weave layer interferes with the serpentine assembly, potentially damaging the metal mesh weave layer. Summary of the Invention

[0004] This invention provides a passive bending section for an endoscope to solve the problems of existing passive bending sections, such as the abutment contact between the serpentine segments easily damaging the metal mesh weave layer when achieving the maximum bending angle, and the metal mesh weave layer lacking elasticity making it difficult to rely on to achieve the maximum bending angle.

[0005] The present invention provides a passive bending section of an endoscope, disposed in the insertion section of the endoscope, wherein the insertion section is inserted into the subject from the front end side along the length axis direction, and the passive bending section includes a snake bone assembly, wherein the snake bone assembly includes a plurality of snake bone segments that are hinged sequentially.

[0006] The passive bending section also includes a woven mesh, which is sleeved on the outer peripheral surface of the snake bone assembly. The woven mesh includes a plurality of woven mesh units connected in sequence.

[0007] When each of the woven mesh units is bent to the maximum bending angle, the passive bending portion reaches the maximum bending angle, and the adjacent serpentine segments maintain a gap.

[0008] According to the present invention, a passive bending section of an endoscope is provided, wherein the woven mesh is formed by weaving multiple thin metal plates into a cylindrical metal tube, and the thin metal plates are composed of multiple metal wires placed in parallel side by side.

[0009] When the passively bent portion reaches its maximum bending angle, the outer edges of the metal sheets in the inner side of the woven mesh unit along the bending direction of the woven mesh abut against each other.

[0010] According to the present invention, in a passive bending section of an endoscope, each of the braided mesh units has equal stiffness, and the braided mesh is transitionally fitted with the snake bone assembly.

[0011] According to the passive bending section of an endoscope provided by the present invention, the stiffness of the plurality of braided mesh units varies periodically, wherein the stiffness of the braided mesh unit sleeved on the outer periphery of the serpentine segment is less than the stiffness of the braided mesh unit sleeved on the arcuate sectional surface of two adjacent serpentine segments.

[0012] According to the present invention, a passive bending section of an endoscope includes a braided mesh unit comprising at least two braided mesh assemblies connected in sequence, wherein the stiffness of the braided mesh assembly with the greatest stiffness gradually increases along the direction from the front end side to the base end side of the insertion section.

[0013] According to the present invention, a passive bending section of an endoscope includes a braided mesh unit comprising a first braided mesh assembly and a second braided mesh assembly connected to the first braided mesh assembly, wherein the stiffness of the first braided mesh assembly is less than the stiffness of the second braided mesh assembly.

[0014] According to the present invention, in a passive bending section of an endoscope, the wire stiffness of the first braided mesh assembly is less than that of the wire stiffness of the second braided mesh assembly.

[0015] According to the present invention, in a passive bending section of an endoscope, the weaving angle of the first braided mesh assembly is smaller than the weaving angle of the second braided mesh assembly.

[0016] According to the present invention, a passive bending section of an endoscope includes a braided mesh unit comprising a first braided mesh assembly, a second braided mesh assembly, a third braided mesh assembly, and a fourth braided mesh assembly connected in sequence. The stiffness of the first braided mesh assembly is less than that of the second braided mesh assembly, the stiffness of the second braided mesh assembly is less than that of the third braided mesh assembly, and the stiffness of the fourth braided mesh assembly is equal to that of the second braided mesh assembly.

[0017] The present invention also provides an endoscope, comprising: a passive bending portion of the endoscope as described in any one of the preceding claims; a flexible portion disposed at the base end side of the passive bending portion; and an active bending portion disposed at the front end side of the passive bending portion; wherein the bending radius of the passive bending portion is greater than the bending radius of the active bending portion.

[0018] The passive bending section of the endoscope provided by this invention utilizes a woven mesh covering the outer periphery of the serpentine assembly. This woven mesh comprises multiple sequentially connected woven mesh units. When each woven mesh unit bends to its maximum bending angle, the passive bending section reaches its maximum bending angle, while maintaining a gap between adjacent serpentine segments. This gap between adjacent serpentine segments allows for a smooth transition in the bending of the entire passive bending section. The overall passive bending of the section within the body cavity is sufficiently smooth, meeting the needs of clinical lesion observation while better adapting to the bending path of the cavity, reducing patient discomfort. Furthermore, this prevents the woven mesh from being bitten into adjacent serpentine segments, thus extending its service life. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the endoscope provided by the present invention.

[0021] Figure 2 This is a side view cross-sectional structural diagram of the flexible part, passive bending part, and active bending part provided by the present invention.

[0022] Figure 3 This is a schematic diagram of the connection relationship between the passive bending part and the active bending part of a conventional endoscope provided by the present invention.

[0023] Figure 4 This is a side view cross-sectional structural diagram of the passive bending section of the endoscope provided by the present invention.

[0024] Figure 5 This is one of the side view structural schematic diagrams of a woven mesh provided in an embodiment of the present invention.

[0025] Figure 6 This is a schematic diagram of the structure of the woven mesh unit provided by the present invention.

[0026] Figure 7 yes Figure 6 A magnified schematic diagram of the structure at point A in the middle.

[0027] Figure 8 This is a second side view structural schematic diagram of a woven mesh provided in one embodiment of the present invention.

[0028] Figure 9 This is the third side view structural schematic diagram of the woven mesh provided in another embodiment of the present invention.

[0029] Figure 10 This is the fourth side view structural schematic diagram of the woven mesh provided in another embodiment of the present invention.

[0030] Figure label:

[0031] 100. Braided mesh; 110. Snake bone assembly; 120. Braided mesh unit; 121. First braided mesh assembly; 122. Second braided mesh assembly; 123. Third braided mesh assembly; 124. Fourth braided mesh assembly; 125. Metal wire; 200. Operating part; 300. Insertion part; 400. Flexible part; 500. Passive bending part; 600. Active bending part; 700. Rigid front end part; 800. Transition joint; 900. Bourdon tube. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0033] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0034] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0035] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0036] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0037] Before introducing the passive bending section 500 of the endoscope, let's first introduce the structure of the endoscope. Figure 1 A schematic diagram of the structure of the endoscope provided by the present invention is shown in the example. Figure 2 A side cross-sectional view of the flexible portion 400, the passive bending portion 500, and the active bending portion 600 provided by the present invention is illustrated, as follows: Figure 1 and Figure 2 As shown, the endoscope includes an operating part 200, an insertion part 300, and a flexible part 400, a passive bending part 500, an active bending part 600, and a rigid front end part 700 arranged sequentially along the base end side of the insertion part 300 toward the front end side. Figure 3 A schematic diagram illustrating the connection relationship between the passive bending portion 500 and the active bending portion 600 of a conventional endoscope provided by the present invention is shown, as follows: Figure 3As shown, in the prior art, the passive bending portion 500 is connected to the rear end of the active bending portion 600 via a transition joint 800, and the passive bending portion 500 is passively bent under the action of external force. Two or four spring tubes 900 are provided inside the passive bending portion 500, and the spring tubes 900 are welded to the transition joint 800. However, in one embodiment of the present invention, the structure of the woven mesh can omit this spring tube 900, and the bending is achieved through the self-rebound action of the woven mesh.

[0038] The following is combined with Figures 4-10 The specific structure of the passive bending portion 500 of the present invention is described.

[0039] Figure 4 A side cross-sectional view of the passive bending section 500 of the endoscope provided by the present invention is illustrated. Figure 5 An example is shown as a side view of one embodiment of the woven mesh provided by the present invention, such as... Figure 4 and Figure 5 As shown, the passive bending section 500 of the endoscope is disposed in the insertion section 300 of the endoscope. The insertion section 300 inserts the subject from the front end along the length axis. The passive bending section 500 includes a snake bone assembly 110, which includes a plurality of snake bone segments that are hinged in sequence. The passive bending section 500 also includes a braided mesh 100, which is sleeved on the outer peripheral surface of the snake bone assembly 110. The braided mesh 100 includes a plurality of braided mesh units 120 that are connected in sequence. When each braided mesh unit 120 is bent to the maximum bending angle, the passive bending section 500 reaches the maximum bending angle, and the adjacent snake bone segments are kept apart.

[0040] The passive bending section 500 of the endoscope provided by the present invention uses a woven mesh covering the outer peripheral surface of the serpentine assembly. The woven mesh includes multiple sequentially connected woven mesh units 120. When each woven mesh unit 120 bends to its maximum bending angle, the passive bending section 500 reaches its maximum bending angle, and adjacent serpentine segments maintain a gap. This prevents the woven mesh from being caught between adjacent serpentine segments, thus avoiding damage and extending its service life. In one embodiment of the present invention, the weaving angle of the woven mesh 100 of the passive bending section 500 is different from that of the woven mesh 100 of the active bending section 600, so that the bending radius of the passive bending section 500 is different from that of the active bending section 600. In another embodiment of the present invention, the stiffness of the multiple woven mesh units 120 varies periodically, wherein the stiffness of the woven mesh unit 120 covering the outer periphery of the serpentine segments is less than the stiffness of the woven mesh unit 120 covering the arcuate sections of two adjacent serpentine segments. With the stiffness of multiple woven mesh units 120 varying periodically, the stiffness of the woven mesh unit 120 fitted around the outer periphery of the snake bone segment is less than the stiffness of the woven mesh unit 120 fitted at the connection between two adjacent snake bone segments. This ensures that after the woven mesh 100 is assembled with the snake bone assembly 110, the outer surface of the passively bent portion 500 is uniform and without obvious protrusions. Furthermore, the arc-shaped cross-section of the snake bone segment opposite the snake bone assembly 110, after being covered by the part of the woven mesh 100 with higher stiffness, will not directly contact the woven mesh 100 during bending, thus avoiding biting the woven mesh 100, damaging the woven mesh 100, and extending the service life of the woven mesh 100.

[0041] It should be noted that the periodic change in stiffness of multiple woven mesh units 120 means that the stiffness of multiple woven mesh units 120 changes in stages, that is, the stiffness of each woven mesh unit 120 changes in the same way, so that the stiffness of multiple woven mesh units 120 changes periodically along the length of the woven mesh 100.

[0042] In one embodiment of the present invention, such as Figure 4 As shown, the snake-bone assembly 110 includes multiple snake-bone segments, each with chamfered arc surfaces of varying sizes at its edges. The passive bending portion 500 achieves its bending function through the interlocking of the opposing arc surfaces of the snake-bone segments. Each snake-bone segment can have the same structure, or different structures can be configured depending on the bending position of the passive bending portion 500. The snake-bone segments are typically ring-shaped or similar structures, capable of bending in multiple directions around a central axis. Adjacent snake-bone segments are connected by connectors (such as rivets, pivots, etc.) to form a continuous bending structure.

[0043] In one embodiment of the present invention, the woven mesh 100 is formed by weaving multiple thin metal sheets into a cylindrical metal tube, wherein the thin metal sheets are composed of multiple metal wires placed side by side in parallel. The metal wires 125 are made of high-strength, corrosion-resistant metal materials, such as stainless steel, nickel-titanium alloy, etc., which can improve the strength and durability of the metal woven mesh; in this embodiment, the metal wires 125 of two adjacent woven mesh assemblies are of the same type.

[0044] Specifically, Figure 6 A schematic diagram of the structure of the woven mesh unit provided by the present invention is shown in the example. Figure 7 yes Figure 6 A magnified view of the local structure at point A, as shown below. Figure 6 and Figure 7 As shown, adjacent metal wires 125 have equal widths, and multiple metal wires 125 arranged side by side form a relatively wide metal sheet. These multiple metal sheets are then woven together to form a woven mesh assembly. In this embodiment, the woven mesh is woven along the concentric axis from the front end of the passively bent portion 500 to the rear end. Of course, it can also be woven in the opposite direction, as long as the stiffness of the woven mesh unit 120 meets the aforementioned requirements.

[0045] In one embodiment of the present invention, the passive bending portion 500 of the endoscope provided by the present invention, when the passive bending portion 500 reaches the maximum bending angle, at the maximum bending angle, the outer edges of the metal sheets in the braided mesh unit 120 along the inner side of the bending direction of the braided mesh 100 abut against each other, thereby limiting the maximum bending angle of the passive bending portion 500.

[0046] Specifically, since the woven mesh 100 has a cylindrical structure, when the metal sheets used for weaving are subjected to bending force, the inner metal sheets will undergo tensile deformation, while the inner metal sheets will be compressed. On the inner side in the bending direction, the metal sheets are forced to move closer together due to compression, forming physical contact. When the woven mesh 100 bends, the metal sheets within the woven mesh unit 120 interact with each other. At the maximum bending angle, the outer edge metal sheet of the woven mesh unit 120 on the bending direction side will abut against the inner edge metal sheet of the adjacent unit. Thus, the bending angle of the woven mesh 100 is limited by the direct contact and mutual abutment of the metal sheets on this side, ensuring that the structure of the woven mesh remains stable at the maximum bending angle and that a predetermined interval is maintained between adjacent serpentine segments.

[0047] In one embodiment of the present invention, the braided mesh unit 120 includes at least two braided mesh assemblies connected in sequence. The stiffness of the braided mesh assembly with the greatest stiffness gradually increases along the direction from the front end side to the base end side of the insertion part 300. By adopting such a stiffness variation law, the resilience of the passive bending part 500 can be enhanced, and the uniformity of the bending state of the passive bending part 500 can be enhanced.

[0048] It should be noted here that the front end of this invention refers to the end furthest from the operator when operating the endoscope, while the end closest to the operator is the rear end. Specifically, as... Figure 5 As shown, the left end of the woven mesh 100 is the front end, and the right end of the woven mesh 100 is the rear end.

[0049] In one embodiment of the present invention, such as Figure 5 As shown, the braided mesh unit 120 includes a first braided mesh assembly 121 and a second braided mesh assembly 122 connected to the first braided mesh assembly 121. The first braided mesh assembly 121 is located at the front end of the braided mesh unit 120, and the second braided mesh assembly 122 is located at the rear end of the braided mesh unit 120. The stiffness of the first braided mesh assembly 121 is less than that of the second braided mesh assembly 122. The first braided mesh assembly 121 is fitted onto the outer periphery of the serpentine segment and conforms to the outer peripheral surface of the serpentine segment. The second braided mesh assembly 122 is fitted onto the connection point of two adjacent serpentine segments and conforms to the chamfered arc surface of the serpentine segment. Because the second woven mesh assembly 122 has high rigidity and fits snugly at the connection points of the two adjacent snake bone segments, the outer surface of the passive bending portion 500 is uniform and without obvious protrusions after the second woven mesh assembly 122 is assembled with the snake bone assembly 110. This also prevents the arc-shaped cross-section of the opposite snake bone segment of the snake bone assembly 110 from directly contacting the second woven mesh assembly 122 when bending, thus avoiding biting the second woven mesh assembly 122 and causing damage to it, and extending the service life of the woven mesh 100.

[0050] In one embodiment of the present invention, there are multiple ways to achieve a stiffness of the first braided mesh assembly 121 that is less than that of the second braided mesh assembly 122. In this embodiment, the stiffness of the metal wire in the first braided mesh assembly 121 is less than that of the metal wire in the second braided mesh assembly 122. When the first braided mesh assembly 121 and the second braided mesh assembly 122 adopt the same braiding angle, in order to make the stiffness of the first braided mesh assembly 121 less than that of the second braided mesh assembly 122, the outer diameter of the metal wire in the first braided mesh assembly 121 is less than that of the metal wire in the second braided mesh assembly 122. Of course, other methods can also be used to change the stiffness of the metal wire 125.

[0051] It should be noted that, in order to make the stiffness of the first woven mesh assembly 121 less than that of the second woven mesh assembly 122, in addition to making the stiffness of the metal wires of the first woven mesh assembly 121 less than that of the metal wires of the second woven mesh assembly 122, it can also be achieved by changing the weaving pattern of the woven mesh assembly.

[0052] In one embodiment of the present invention, the weaving angle of the first woven mesh assembly 121 is smaller than the weaving angle of the second woven mesh assembly 122. In this embodiment, the weaving angle of the first woven mesh assembly 121 is 100°, and the weaving angle of the second woven mesh assembly 122 is 120°. Of course, the weaving angle of the woven mesh assembly is not limited to these values ​​and can be determined according to actual needs. Since a smaller weaving angle results in a lower weaving density and lower stiffness, the stiffness of the first woven mesh assembly 121 is less than that of the second woven mesh assembly 122. Different maximum bending angles can be achieved by controlling the weaving angle of the mesh fabric to vary along the insertion direction.

[0053] In one embodiment of the present invention, the length of the first braided mesh assembly 121 is greater than the length of the second braided mesh assembly 122. It should be noted that the length of the braided mesh assembly refers to the dimension along the axial direction of the braided mesh 100, i.e. Figure 5 The dimensions in the left-right direction. Of course, the length relationship between the first woven mesh assembly 121 and the second woven mesh assembly 122 is not limited to this, and is specifically determined according to the length of the corresponding snake segment and the length of the connection between two adjacent snake segments.

[0054] In a preferred embodiment of the present invention, the stiffness of the second braided mesh assembly 122 gradually increases along the direction from the front end side to the base end side of the insertion portion 300, that is, the stiffness of the second braided mesh assembly 122 gradually increases along the direction from the front end side to the base end side. Figure 5 The diameter gradually increases from left to right. This arrangement enhances the resilience of the passive bending section 500 and improves the uniformity of its bending state.

[0055] Figure 8 A second side view structural schematic diagram of a woven mesh provided in an embodiment of the present invention is illustrated, as shown below. Figure 8 As shown, to better understand the relationship between the stiffness of the braided mesh unit 120 and the stiffness of the first braided mesh assembly 121 and the second braided mesh assembly 122, the stiffness of the braided mesh 100 is denoted as K, the stiffness of the first braided mesh assembly 121 is denoted as k1, and the stiffness of the second braided mesh assembly 122 is denoted as k2, where k2 > k1, and k2 and k1 satisfy the following relationship: The overall stiffness of the woven mesh 100 can be varied by changing the stiffness of the first woven mesh assembly 121 and the second woven mesh assembly 122, or by changing either the first woven mesh assembly 121 or the second woven mesh assembly 122 individually. The greater the overall stiffness of the woven mesh 100, the smaller the interlocking angle between adjacent serpentine segments, and the smaller the bending angle of the bending component.

[0056] In another embodiment of the invention, Figure 9 Example three is a side view structural schematic diagram of a woven mesh provided in another embodiment of the present invention, as shown in Figure 3. Figure 9 As shown, the braided mesh unit 120 includes a first braided mesh assembly 121, a second braided mesh assembly 122, a third braided mesh assembly 123, and a fourth braided mesh assembly 124 connected in sequence. The first braided mesh assembly 121 is located at the front end of the braided mesh unit 120, and the fourth braided mesh assembly 124 is located at the rear end of the braided mesh unit 120. The stiffness of the first braided mesh assembly 121 is less than that of the second braided mesh assembly 122, the stiffness of the second braided mesh assembly 122 is less than that of the third braided mesh assembly 123, and the stiffness of the fourth braided mesh assembly 124 is equal to that of the second braided mesh assembly 122. This results in the braided mesh unit 120 exhibiting a four-stage stiffness variation from weak to medium-strong, and then back to medium-strong, to meet the bending angle setting requirements of the passive bending section 500. By setting a fourth braided mesh assembly 124 with medium to strong stiffness between the third braided mesh assembly 123 of the previous braided mesh unit 120 and the first braided mesh assembly 121 of the next braided mesh unit 120, the stiffness of the braided mesh 100 can be made to change more smoothly during the process of strong and weak changes, thereby enhancing the uniformity of the bending state of the passive bending section 500.

[0057] It should be noted that in this embodiment, the braided mesh unit 120 includes four braided mesh components. Of course, the number of braided mesh components is not limited to four; it can also be three, five, or more.

[0058] In one embodiment of the present invention, the wire stiffness of the first braided mesh assembly 121 is less than the wire stiffness of the second braided mesh assembly 122, the wire stiffness of the second braided mesh assembly 122 is less than the wire stiffness of the third braided mesh assembly 123, and the wire stiffness of the fourth braided mesh assembly 124 is equal to the wire stiffness of the second braided mesh assembly 122.

[0059] It should be noted that, in order to achieve different stiffnesses among the four woven mesh components, in addition to making the metal wires of the four woven mesh components have different stiffnesses, it can also be achieved by changing the weaving pattern of the woven mesh components.

[0060] In one embodiment of the present invention, the length of the first woven mesh assembly 121 is greater than the length of the second woven mesh assembly 122, the length of the second woven mesh assembly 122 is greater than the length of the third woven mesh assembly 123, and the length of the fourth woven mesh assembly 124 is equal to the length of the second woven mesh assembly 122. Of course, the length relationship of the four woven mesh assemblies is not limited to this, and is specifically determined based on the length of the corresponding serpentine segment and the length of the connection between two adjacent serpentine segments.

[0061] In a preferred embodiment of the present invention, the stiffness of the third braided mesh assembly 123 gradually increases along the direction from the front end side to the base end side of the insertion portion 300, that is, the stiffness of the third braided mesh assembly 123 gradually increases along the direction from the front end side to the base end side. Figure 8 The diameter gradually increases from left to right. This arrangement enhances the resilience of the passive bending section 500 and improves the uniformity of its bending state.

[0062] Figure 10 Example four is a side view structural schematic diagram of a woven mesh provided in another embodiment of the present invention, as shown in Figure 4. Figure 10 As shown, to better understand the relationship between the stiffness of the braided mesh unit 120 and the stiffness of the four braided mesh components, the stiffness of the braided mesh 100 is denoted as K, the stiffness of the first braided mesh component 121 is denoted as k1, the stiffness of the second braided mesh component 122 and the fourth braided mesh component 124 is denoted as k2, and the stiffness of the third braided mesh component 123 is denoted as k3, where k3 > k2 > k1, and k 1、 k2 and k3 satisfy the following relationship: , The overall stiffness of the woven mesh 100 can be changed by altering the stiffness of the first woven mesh assembly 121, the second woven mesh assembly 122, the third woven mesh assembly 123, and the fourth woven mesh assembly 124, or by individually changing the stiffness of any one of these assemblies. The greater the overall stiffness of the woven mesh 100, the smaller the interlocking angle between adjacent serpentine segments, and the smaller the bending angle of the bending assembly.

[0063] In another embodiment of the present invention, the woven mesh 100 includes a plurality of woven mesh units 120 connected in sequence, each woven mesh unit 120 having equal stiffness, that is, the woven mesh 100 has uniform stiffness, and the woven mesh 100 is transitionally fitted with the snake-bone assembly 110. Due to the transitional fit between the woven mesh 100 and the snake-bone assembly 110, expansion deformation will occur between the woven mesh 100 and the snake-bone assembly 110 due to the presence of interference fit. This expansion deformation will cause the woven mesh 100 to form an elastic force, which will give the woven mesh 100 stronger rigidity.

[0064] The present invention also provides an endoscope, the endoscope including a flexible portion 400, an active bending portion 600 and a passive bending portion 500 as described in any one of the above. The flexible portion 400 is disposed on the base end side of the passive bending portion 500, the active bending portion 600 is disposed on the front end side of the passive bending portion 500, and the bending radius of the passive bending portion 500 is greater than the bending radius of the active bending portion 600.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A passive bending section of an endoscope, disposed in the insertion section (300) of the endoscope, wherein the insertion section (300) is inserted into the subject from the front end side along the length axis, characterized in that, The passive bending portion (500) includes a snake bone assembly (110), which includes a plurality of snake bone segments that are hinged in sequence. The passive bending portion (500) further includes a woven mesh (100), which is sleeved on the outer peripheral surface of the snake bone assembly (110). The woven mesh (100) includes a plurality of woven mesh units (120) connected in sequence. The stiffness of the woven mesh unit (120) sleeved on the outer periphery of the snake bone segment is less than the stiffness of the woven mesh unit (120) sleeved on the arcuate sectional surface of two adjacent snake bone segments. When each of the woven mesh units (120) is bent to the maximum bending angle, the passive bending portion (500) reaches the maximum bending angle, and the adjacent serpentine segments remain spaced apart.

2. The passive bending portion of the endoscope according to claim 1, characterized in that, The woven mesh (100) is formed by weaving multiple metal sheets into a cylindrical metal tube, and the metal sheets are made of multiple metal wires (125) placed side by side in parallel.

3. The passive bending portion of the endoscope according to claim 2, characterized in that, When the passive bending portion (500) reaches its maximum bending angle, the outer edges of the metal sheets in the woven mesh unit (120) on the inner side of the bending direction of the woven mesh (100) abut against each other.

4. The passive bending portion of the endoscope according to claim 1, characterized in that, Each of the woven mesh units (120) has equal stiffness, and the woven mesh (100) transitions into the snake bone assembly (110).

5. The passive bending portion of the endoscope according to any one of claims 1 to 3, characterized in that, The stiffness of the plurality of braided mesh units (120) varies periodically. Each braided mesh unit (120) includes at least two braided mesh assemblies connected in sequence. The stiffness of the braided mesh assembly with the greatest stiffness gradually increases along the direction from the front end side to the base end side of the insertion part (300).

6. The passive bending portion of the endoscope according to claim 5, characterized in that, The braided mesh unit (120) includes a first braided mesh assembly (121) and a second braided mesh assembly (122) connected to the first braided mesh assembly (121), wherein the stiffness of the first braided mesh assembly (121) is less than the stiffness of the second braided mesh assembly (122).

7. The passive bending portion of the endoscope according to claim 6, characterized in that, The wire stiffness of the first woven mesh assembly (121) is less than that of the wire stiffness of the second woven mesh assembly (122).

8. The passive bending portion of the endoscope according to claim 6, characterized in that, The weaving angle of the first woven mesh assembly (121) is smaller than the weaving angle of the second woven mesh assembly (122).

9. The passive bending portion of the endoscope according to claim 5, characterized in that, The braided mesh unit (120) includes a first braided mesh assembly (121), a second braided mesh assembly (122), a third braided mesh assembly (123), and a fourth braided mesh assembly (124) connected in sequence. The stiffness of the first braided mesh assembly (121) is less than that of the second braided mesh assembly (122), the stiffness of the second braided mesh assembly (122) is less than that of the third braided mesh assembly (123), and the stiffness of the fourth braided mesh assembly (124) is equal to that of the second braided mesh assembly (122).

10. An endoscope, characterized in that, include: The passive bending portion of the endoscope as described in any one of claims 1 to 9; A flexible portion (400) is provided on the base end side of the passively bent portion (500); An active bending portion (600) is provided on the front end side of the passive bending portion (500); The bending radius of the passive bending portion (500) is greater than that of the active bending portion (600).

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