CN115316914A

CN115316914A - Bendable structure, flexible instrument and endoscope

Info

Publication number: CN115316914A
Application number: CN202210938055.1A
Authority: CN
Inventors: 不公告发明人
Original assignee: Shanghai Microport Medbot Group Co Ltd
Current assignee: Shanghai Microport Medbot Group Co Ltd
Priority date: 2022-08-05
Filing date: 2022-08-05
Publication date: 2022-11-11

Abstract

The invention relates to a bendable structure, a flexible instrument and an endoscope. The bendable structure is including connecting, connects including two ring pieces, and every ring piece is equipped with two at least relative bellying and two at least relative depressed part, and bellying and depressed part set up along ring piece circumference interval, and bellying and depressed part are protruding along the axial not equidirectional of ring piece respectively, connect through the curved surface between bellying and the depressed part, and two ring pieces in the joint are connected through bellying or depressed part. The invention can reduce the risk of breakage at the bending part while bending the bendable structure, and can realize batch production and reduce the production cost.

Description

Bendable structure, flexible instrument and endoscope

Technical Field

The invention relates to the field of medical instruments, in particular to a bendable structure, a flexible instrument and an endoscope.

Background

The endoscope is a common medical instrument, is a common detection instrument in modern medical diagnosis and treatment, can enter the stomach through a mouth or enter the body through other natural pore canals, and can enter the body through a small incision made by an operation. The doctor can see the lesion which cannot be displayed by the X-ray by means of the endoscope, and is very useful for diagnosing the condition. When the head of a conventional endoscope is bent and steered, the endoscope needs to be controlled by a self-provided bendable structure. The current bendable structure is usually a snake bone structure, but the current snake bone structure is easy to break at the bending part, and the structure is very complex, so that the processing and assembling process is also complex, and the production cost is increased.

Disclosure of Invention

The invention aims to provide a bendable structure, a flexible instrument and an endoscope, and aims to solve the problems that the bendable structure used by the flexible instrument in the prior art is easy to break, complex in structure, high in production cost and the like.

The invention provides a bendable structure which comprises a joint, wherein the joint comprises two ring sheets. Each ring segment is provided with at least two opposite protrusions and at least two opposite recesses. The convex parts and the concave parts are arranged at intervals along the circumferential direction of the ring piece. The convex part and the concave part are respectively protruded along different axial directions of the ring piece. The convex part and the concave part are connected through a curved surface. Two of the ring pieces in the joint are connected by the convex part or the concave part. When so set up, both can ensure the bending property of flexible structure, make the flexible structure be difficult to the fracture in bending process again, simple structure is convenient for processing and assembly moreover.

In one embodiment, two ring pieces in the joint are arranged symmetrically in the axial direction of the bendable structure in a mirror mode, so that the production cost is reduced, the force of the bendable structure is more uniform, and the bending effect is better.

In one embodiment, the loop width of the loop is 5 to 10 times the thickness of the loop, so that the loop has sufficient bending strength and deformation performance, and the phenomenon that the passing performance is affected due to the overlarge size of the bendable structure can be prevented.

In one embodiment, the thickness of the ring sheet is not more than 0.3mm to ensure good deformation properties of the ring sheet.

In one embodiment, the ring piece has an even number of the convex portions, and the number of the concave portions is the same as the number of the convex portions. Since the number of the traction bodies controlling the bendable structure is mostly even, the number of the protrusions and the recesses is also set to be even.

In an embodiment, the bendable structure is formed by connecting a plurality of joints in sequence in an axial direction of the bendable structure, so that the bendable structure can realize bending with a larger angle.

In one embodiment, the flexibility of the bendable structure in the axial direction is not the same, so as to more accurately control and position the head structure of the flexible instrument and also enable the flexible instrument to be suitable for different use scenes.

In one embodiment, the flexibility of the plurality of joints decreases gradually from the distal end to the proximal end in the axial direction of the bendable structure, so that the distal end of the bendable structure has the maximum flexibility to be easily bent and deformed to fit a tortuous or narrow portion.

In one embodiment, a plurality of the ring pieces are welded in sequence in the axial direction of the bendable structure, so that the flexibility of the bendable structure in the axial direction is controlled by adjusting the welding force.

The invention also provides a flexible instrument which comprises a main body and any one bendable structure, wherein the bendable structure is arranged at the distal end of the main body.

In one embodiment, the flexible instrument further comprises a positioning sleeve, wherein the positioning sleeve is coated on the bendable structure, so that the bendable structure can be positioned through the positioning sleeve, and damage to target tissues caused by the bendable structure when the bendable structure passes through the cavity channel can be reduced.

In one embodiment, the flexible instrument further comprises a pulling member, wherein the distal end of the pulling member is fixedly connected with the distal end of the bendable structure, and the proximal end of the pulling member sequentially penetrates all the ring sheets to bend the bendable structure under the control of the pulling member.

The invention also provides an endoscope which adopts any flexible instrument.

Compared with the prior art, the bendable structure comprises a joint, the joint comprises two ring sheets, each ring sheet is provided with at least two opposite protruding parts and at least two opposite recessed parts, the protruding parts and the recessed parts are arranged at intervals along the circumferential direction of the ring sheet, the protruding parts and the recessed parts respectively protrude along different axial directions of the ring sheet, the protruding parts and the recessed parts are connected through curved surfaces, and the two ring sheets in the joint are connected through the protruding parts or the recessed parts. Because the ring pieces have deformable characteristics, and the curved surfaces between the convex parts and the concave parts can bring larger deformation, when the joint is constructed by the two ring pieces, the joint can be well deformed and bent, and the bending performance of the bendable structure is ensured. In addition, because the ring structure is used, the joint also has the characteristic of a wide plate, the bendable structure is not easy to break in the bending process, particularly, the contact area between the joints is large, the bendable structure is not easy to break even if the bendable structure is bent for multiple times, the structural strength of the whole bendable structure is ensured, the reliability is good, the structure of the joint is simple, the processing and assembling processes are simplified, and the production cost is reduced. The ring sheets in the bendable structure can be integrally punched into lines, and the processing cost is lower.

Drawings

The features, nature, and advantages of embodiments of the invention will be described with reference to the accompanying drawings, in which:

FIG. 1 is a schematic view of the overall construction of an endoscope in accordance with an embodiment of the present invention;

FIG. 2 is a schematic view of an overall bending structure of the bendable structure according to the embodiment of the invention;

FIG. 3 is an overall curved side view of a bendable structure according to an embodiment of the invention;

FIGS. 4 and 5 are overall initial state front and cross-sectional views, respectively, of a bendable structure according to an embodiment of the invention;

FIG. 6 is a top view of a distal link of an embodiment of the present invention;

FIG. 7 is a schematic overall perspective view of a ring plate according to an embodiment of the present invention;

FIG. 8 is an elevation view of a segment having two protrusions and two depressions according to an embodiment of the present invention;

FIG. 9 is a top view of a ring plate having two protrusions and two depressions according to an embodiment of the present invention;

FIG. 10 is an elevation view of a joint according to an embodiment of the present invention;

FIG. 11 is a front view of a joint according to an embodiment of the present invention in a bent state;

FIG. 12 is an elevation view of a ring plate having four protrusions and four depressions in accordance with an embodiment of the present invention;

FIG. 13 is a top view of a ring segment having four protrusions and four depressions according to an embodiment of the present invention;

FIG. 14 is an elevational view of a plurality of joints connected in series to form a bendable structure according to an embodiment of the invention in an initial state;

FIG. 15 is a schematic view of a plurality of joints connected in sequence to form a bendable structure according to an embodiment of the present invention;

FIG. 16 is a cross-sectional view of a positioning sleeve wrapped around the exterior of a bendable structure according to an embodiment of the invention.

Detailed Description

To further clarify the objects, advantages and features of the present invention, a more particular description of the invention will be rendered by reference to the appended drawings. It is to be noted that the drawings are in simplified form and are not to scale, but are merely intended to facilitate and clarify the explanation of the embodiments of the present invention.

As used in this specification, the terms "a" or "an," and the like, do not denote a limitation of quantity, but rather denote the presence of at least one; "plurality" means two or more than two; the meaning of "a number" is that the number is not limiting. As used in this specification, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise. Furthermore, in the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the invention. In the following description, for convenience of description, "axial" and "circumferential" are used, and "proximal" and "distal" are also used; "axial" refers to the axial direction of a bendable structure or flexible instrument; "circumferential" refers to directions about the axis of a bendable structure or flexible instrument; "proximal" refers to a direction closer to the operator; "distal" refers to a direction closer to the patient.

The core of the invention is to provide a bendable structure, which comprises a joint, wherein the joint comprises two ring sheets. Each ring segment is provided with at least two opposite protrusions and at least two opposite recesses. The convex parts and the concave parts are arranged at intervals along the circumferential direction of the ring piece. The convex part and the concave part are respectively protruded along different axial directions of the ring piece. The convex part and the concave part are connected through a curved surface. Two of the ring pieces in the joint are connected by the convex portion or the concave portion.

The present invention does not require any special number of joints in the bendable structure. The number of joints in the bendable structure is set according to actual requirements, and generally, the larger the number of joints, the larger the bending angle.

The bendable structure of the invention adopts the ring sheets with thick plate width and short plate height to form the joint, and the structure ensures that the joint can be bent, is not easy to break due to the thick plate width of the ring sheets, is easy to process and form, does not need complicated processing and assembling processes, and is suitable for batch production.

The bendable structure is mainly applied to the flexible instrument to control the bending of the tail end of the flexible instrument, and can realize the rotation of any angle.

The invention relates to a flexible instrument which comprises a main body and a bendable structure. The bendable structure is disposed at a distal end of the body. The flexible instrument may further comprise a pulling member having a distal end fixedly attached to the distal end of the bendable structure, and a proximal end passing through all of the loop pieces in sequence.

The flexible instrument according to the present invention can be applied to endoscopes and also to other medical instruments for performing surgical operations. The flexible apparatus of the present invention may be a single use product or a reusable product.

The present application will be further described with reference to the drawings and preferred embodiments, and features of the embodiments and the embodiments described below may be supplemented with or combined with each other without conflict. In the following description, the endoscope is shown for illustration, but the application is not intended as a limitation on the invention, and a person skilled in the art will be able to modify the description to obtain other flexible instruments than endoscopes.

Referring to fig. 1 to 3, the present embodiment provides an endoscope, which is used as a flexible instrument and includes a head structure 1 (which may be referred to as a tip portion), a bendable structure 2 and a main body 3, which are connected in this order from a distal end to a proximal end in an axial direction. Head structure 1 carries the module of making a video recording, can realize the image monitoring of internal environment. The bendable structure 2 drives the head structure 1 to bend so as to accurately position a target position to be shot. The main body 3 is hollow tubular, so that the whole endoscope can be conveniently pushed, and the operation of the endoscope in a human body is realized.

The bendable structure 2 comprises at least one elastically deformable joint 21, preferably at least three joints 21, allowing the bending structure 2 to be bent by means of the joints 21. The bendable structure 2 can bend and swing 360 degrees in all directions, as illustrated by a plurality of joints 21. The bendable structure 2 is also understood to be a snake bone structure, in this application the bendable structure 2 utilizes elastic deformation of the joint 21 itself to achieve bending. The bendable structure 2 has an initial state and a bent state; in the initial state, the bendable structure 2 is not bent, i.e. as shown in fig. 4 and 5.

As shown in fig. 4 and 5, the bendable structure 2 bends under the control of the pulling member 4. The far end of the traction part 4 is fixedly connected with the far end of the bendable structure 2, the near end of the traction part 4 is connected with a control part at the near end of the endoscope, and the control part drives the traction part 4 to move. The rotation in the corresponding direction can be realized by pulling one of the traction pieces 4, and the rotation control at any angle can be realized by controlling two or more traction pieces 4. The pulling element 4 passes through all of the joints 21 and out of the proximal end of the bendable structure 2. The pulling member 4 is preferably attached to the distal end of the bendable structure 2 by welding. The distal end of the pulling element 4 may be connected directly to the nipple 21 or indirectly to the nipple 21. The traction element 4 is such as: wires, ropes, strips or bands, etc., generally elastic wires are used.

As an embodiment, the bendable structure 2 may further include a distal end connecting member 22 disposed at the distal most end, and the distal end of the pulling member 4 is fixedly connected to the distal end connecting member 22. As shown in fig. 6, the distal connecting element 22 may be a ring-shaped structure, the ring surface of which is fixed, preferably welded, to the distal end of the pulling element 4, for example, 4 welding points 221 are formed on the ring surface of the distal connecting element 22, the welding points 221 are generally arranged at 90 degrees in a staggered manner, that is, the pulling element 4 is generally in four forms which are uniformly distributed at 90 degrees. The structure of the distal connecting member 22 may be the same as or different from the structure of the ring plate 211. The head structure 1 may be mounted directly on the distal connector 22. Further, a proximal connector may be provided at the proximal end of the bendable structure 2, the proximal connector being directly connected to the distal end of the main body 3. The structure of the proximal connector may or may not be the same as the structure of the ring plate 211.

Referring to fig. 7 and 8 in combination with fig. 4 and 5, the joint 21 includes two ring pieces 211 stacked in the axial direction of the bendable structure 2. By "stacked" is meant that the ring pieces 211 are stacked in the axial direction of the bendable structure 2 and the two are fixedly connected. Each ring plate 211 is provided with at least two opposing protrusions 211a and at least two opposing recesses 211b. The convex portions 211a and the concave portions 211b are provided at intervals in the circumferential direction of the ring piece 21. The convex portion 211a and the concave portion 211b are respectively convex in different directions in the axial direction of the ring piece 21. The convex portion 211a and the concave portion 211b are connected by a curved surface 211 c. Preferably, the convex portion 211a and the concave portion 211b are connected by a smooth curved surface 211c, and it can also be understood that a free curved surface 211c with continuous curvature is formed between the convex portion 211a and the concave portion 211b, and the continuous curvature limits smooth transition between the convex portion 211a and the curved surface 211c and also limits smooth transition between the concave portion 211b and the curved surface 211c, so as to reduce stress concentration.

The ring plate 211 is preferably stamped and formed in one step. Most of the ring pieces 211 need to be bent during machining, and if the radius of curvature of the bent portion is small, the bent portion will generate large stress, so that the radius of curvature of the bent portion is at least 5 times the thickness of the ring pieces 211 to avoid the large stress of the bent portion. In the processing process, the ring sheet 211 is subjected to heat treatment according to the use performance requirement to ensure the hardness, for example, the hardness can be 36-52 HRC, so that the fracture risk is reduced. The ring plate 211 itself is made of an elastic material, such as a metallic material or a non-metallic material. The ring piece 211 can be made of phosphor bronze, tin bronze, 65Mn, 55i2Mn, 60Si2MnA, 55 simnbv, 55 simmnmov, 60CrMn, 60CrMnB, 302, 316, or other types of flat steel strips. The material of the ring piece 211 is, for example, a plastic with good elasticity, such as ABS. The ring piece 211 is of a symmetrical structure, can be turned over in the front and back direction for use, and has no possibility of error assembly.

In actual use, the two ring pieces 211 in the joint 21 are connected by the convex portions 211a, and the convex portions 211a are directly connected, that is, all the convex portions 211a in one ring piece 21 and all the convex portions 211a in the other ring piece 21 are directly connected, or the two ring pieces 211 in the joint 21 are connected by the concave portions 211b, and the concave portions 211b are directly connected, that is, all the concave portions 211b in one ring piece 21 and all the concave portions 211b in the other ring piece 21 are directly connected. In the embodiment of the present application, no additional parts are needed to connect between the two ring pieces 211 in the joint 21 and between the joints 21, and the assembly process is simple.

Therefore, by virtue of the elastically deformable property of the ring piece 211 itself, the joint 21 can be deformed and bent well, ensuring the bending performance of the bendable structure 2. Moreover, the ring piece 211 has the characteristics of a thick plate and a wide plate, is not easy to break in the bending process, especially the contact area among the joints 21 is large, and is not easy to break even if the bending is performed for multiple times, so that the structural strength of the whole bendable structure 2 is ensured, and the reliability is good. And the processing and the assembly of the joint 21 are easy to realize, thereby reducing the production cost. Particularly, the ring sheets 211 can be punched into a whole in a row, and the processing cost is lower. The bendable structure 2 has good mechanical stability and controllable motion, and can ensure the motion control precision.

All the convex parts 211a on the ring piece 211 are distributed in the same plane, and all the concave parts 211b are also distributed in the same plane, so that the controllability of the movement is ensured, and the control difficulty is reduced.

Referring to fig. 7 to 9, the ring piece 211 has a thicker ring width W (i.e., a plate width) and a smaller plate thickness H (i.e., a plate height). Preferably, the width W of the ring piece 211 is 5 to 10 times the thickness H of the ring piece 211, so that the ring piece 211 has sufficient bending strength and also has deformation performance, and the bendable structure 2 can be prevented from being too large to affect the passing performance. Further, the thickness H of the ring piece 211 is not more than 0.3mm, so as to ensure that the ring piece has better deformation performance. Therefore, the ring piece 211 is made of flexible material, and has the advantages of easy deformation and bending, difficult fracture due to the large ring width W, easy processing and forming, and suitability for mass production. It should be further understood that the ring plate 211 can be elastically deformed, and the rigidity of the curved surface 211c between the convex portion 211a and the concave portion 211b is lower than that of the convex portion 211a and the concave portion 211b, so that when a force is applied, the deformation range of the curved surface 211c is larger, and the deformability of the ring plate 211 is ensured.

In the embodiment of the present application, the bendable structure 2 is generally formed by connecting a plurality of joints 21 in sequence in the axial direction of the bendable structure 2, so that the bendable structure 2 can realize bending at a larger angle. Any two adjacent joints 21 are directly connected through the convex part 211a or the concave part 211b, and generally, welding is preferred.

As shown in fig. 4 and 5, and fig. 7 and 8, as a specific embodiment, the ring piece 211 has two convex portions 211a and two concave portions 211b, and the two concave portions 211b of one ring piece 211 and the two concave portions 211b of the other ring piece 211 in the joint 21 are directly welded and fixed. It will be appreciated that the two ring segments 211 are arranged turned 180 deg. to form a joint 21. At this time, adjacent two joints 21 may be directly welded and fixed by the convex portion 211a between the ring pieces 211 to form a stable mechanical structure.

As another specific example, as shown in fig. 12 to 15, the ring piece 211 has four protrusions 211a and four recesses 211b, and the four recesses 211b of one ring piece 211 and the four recesses 211b of the other ring piece 211 in the joints 21 are directly welded and fixed, and at this time, two adjacent joints 21 may be directly welded and fixed by the four protrusions 211a between the ring pieces 211.

The two ring segments 211 in the joint 21 may be arranged in mirror symmetry in the axial direction of the bendable structure 2, or may be arranged in non-mirror symmetry. Preferably, two ring pieces 211 in the joint 21 are symmetrically arranged in the axial direction of the bendable structure 2, and at this time, all the ring pieces 211 have the same structure, so that the production cost is low, the stress is more uniform, and the bending effect is better.

After the distal end of the pulling element 4 is fixed to the distal end of the bendable structure 2, the proximal end of the pulling element 4 is connected to the control unit after passing through each joint 21 in sequence. The traction piece 4 passes through the position of each ring piece 211 corresponding to the convex part 211a or the concave part 211 b; if two ring pieces 21 in the joint 21 are connected through the concave part 211b, the traction piece 4 passes through the position of each ring piece 211 corresponding to the convex part 211 a; if two ring pieces 211 in the joint 21 are connected by the convex portion 211a, the pulling member 4 passes through the position of each ring piece 211 corresponding to the concave portion 211b. The ring 211 may be any suitable shape, similar to a leaf spring structure, not only having good flexibility, but also being not easily broken. The ring piece 211 is provided with through positioning holes 211d, the positioning holes 211d are provided on the concave portion 211b or the convex portion 211c, and each positioning hole 211d allows only one pulling member 4 to pass through. In one embodiment, the ring plate 211 has 4 positioning holes 211d uniformly distributed thereon (see fig. 13 or fig. 9). The positioning hole 211d may have any suitable shape, such as a semi-circle, a full circle, or other shapes, and preferably the positioning hole 211d is flanged. Flanging refers to forming a straight wall or a flange with a certain angle along the closed or unclosed curve edge of the positioning hole 211d by using the action of a mold. Due to the arrangement of the flanging, the contact area between the traction piece 4 and the positioning hole 211d is increased, and the abrasion of the traction piece 4 is reduced.

As described above, the ring piece 211 may have two convex portions 211a and two concave portions 211b, and one concave portion 211b is disposed between the two convex portions 211 a. The ring piece 211 may further have four protrusions 211a and four recesses 211b, and one recess 211b is disposed between any two protrusions 211 a. Of course, the ring piece 211 may have more protrusions 211a and recesses 211b, which are generally set according to the number of the pulling members 4. Since the pulling member 4 is generally even, the number of the protrusions 211a and the recesses 211b is also an even number, and for example, the number of the pulling members 4 can be 2, 4, 8 or 16, so that the number of the protrusions 211a and the recesses 211b is usually 2, 4, 8 or 16.

In some embodiments of the present application, the bendable structure 2 may be integrally or integrally formed, such as laser cutting or 3D printing, and the ring pieces 211 are not required to be assembled one by one, so that the assembly is simpler.

In other embodiments of the present application, the bendable structure 2 may be formed by separate processes, such as stamping the ring sheet 211, and then assembling and connecting a plurality of ring sheets 211.

The overall compliance of the bendable structure 2 in the axial direction may or may not be the same, preferably not the same. When the flexibility of the bendable structure 2 in the axial direction is not the same, so as to more precisely control the positioning of the head structure 1 of the endoscope, the endoscope can also be adapted to different use scenarios. The flexibility is also called slenderness ratio, a concept of mechanics, often called λ, refers to the size of deformation of a component along a vertical axial direction under the condition of axial stress, and the larger the flexibility is, the easier the deformation is.

Preferably, the flexibility of the plurality of joints 21 decreases gradually from the distal end to the proximal end in the axial direction of the bendable structure 2, so that the distal end of the bendable structure 2 has the maximum flexibility to be easily bent and deformed to fit a tortuous or narrow portion. Preferably, the bendable structure 2 is formed by separate machining, and the plurality of ring pieces 211 are sequentially welded in the axial direction of the bendable structure 2, so that the flexibility of the bendable structure 2 in the axial direction is controlled by adjusting the welding force. For example, the welding force between the ring pieces 211 and the welding force between the joints 21 affect the flexibility of the bendable structure 2 in the axial direction, and may be reduced if the flexibility needs to be increased, or increased if the flexibility needs to be reduced. The size of the welding force is related to the strength of the welding spot, the strength of the welding spot is related to the size of the welding spot, and the welding force is adjusted by controlling the size of the welding spot. The welding point specifically sets up around locating hole 211d, and the welding point can have big or small, and the size accessible welding process of welding point adjusts.

Next, the structural principle of the bendable structure 2 will be further described.

Fig. 10 shows the structure of one joint 21 (which is the smallest unit) in which the ring piece 211 has two convex portions 211a and two concave portions 211b. At this time, the joint 21 includes two ring pieces 211 having the same structure, and the two ring pieces 211 are mirror-symmetrical in the axial direction of the bendable structure 2 to form a bidirectional snake bone. The two ring pieces 211 are welded at the concave part 211b to form an anchor point a. With further reference to fig. 11, it can be seen from fig. 11 that when the joint 21 is bent, the positioning hole 211d is used as a traction point to perform deflection, and the connection position between the two ring pieces 211 is used as an anchor point a to perform bending, and the curved surface 211c is the largest deformation section.

Fig. 12 and 13 show a ring plate 211 having four recesses 211b and four protrusions 211c, which is more suitable for the case of four traction elements 4 control. As shown in fig. 14, when the ring piece 211 has four convex portions 211a, the curved surface 211c is shorter, which is more advantageous for integral one-time molding. Similarly, when the ring piece 12 has more protrusions 211a, for example, 8 protrusions 211a, the length of the curved surface 211c is further shortened. As shown in fig. 15, when the ring piece 211 has four convex portions 211a, the bendable structure 2 can achieve a bending effect of 180 ° when the number of the joints 21 in the bendable structure 2 is sufficiently large. More joints 21 can be arranged if a larger bending angle is desired. Furthermore, as is also clear from fig. 15, the effect of the bending deformation of the bendable structure 2 is not due to relative rotation and sliding between the structures, but due to the deformability of the ring segments 211 themselves, which deformation requires sufficient strength of the material to ensure that it does not break. If a conventional laser cutting design for thin plates is used, it is very likely that the fracture will occur in several bends. Thus, the bendable structure 2 of the present invention is built on a sufficient sheet width and elastic material, while giving the sheet width to the passage through the pulling member 4 without loss of internal space. When the bendable structure 2 needs to be assembled from the stack of ring segments 211. Since the positioning hole 211d and the anchor point a of the ring piece 211 are all along the axial direction, the bendable structure 2 can be positioned in an external circle manner.

As shown in fig. 16, the endoscope may further include a positioning sleeve 5, the positioning sleeve 5 is covered on the bendable structure 2, and the positioning sleeve 5 may be a braided tube. The positioning sleeve 5 can not only position the bendable structure 2, but also reduce the damage of the bendable structure 2 to the target tissue when passing through the cavity.

The application provides a bendable structure 2 if form by piling up of identical ring piece 211, part kind is few, and assembly cost is low, and when especially integrated into one piece, more can reduction in production cost, specially adapted is applicable once only. The ring pieces 211 can be designed into a butterfly-shaped plate spring, large deformation is ensured by utilizing the elastic deformation property and the special radian structure of the butterfly-shaped plate spring, the bending performance is ensured, and because the butterfly-shaped plate spring has the property of a wide plate, the butterfly-shaped plate spring is not easy to break, and the contact surface between the ring pieces 211 is larger, the effect is more reliable when the butterfly-shaped plate spring is bent for multiple times during welding and fixing. And the butterfly-shaped plate spring also has enough width to provide enough welding area and ensure welding strength. The ring piece 211 is simple in structure and can be continuously punched, positioning holes can be formed during punching, a flanging with a certain size can be pressed, and the processing cost is low. After the plurality of joints 21 are welded and assembled, the single-direction rotation can be generated by using the traction of the single traction piece 4. In the operation process, an operator pulls two adjacent traction pieces 4 simultaneously, so that the rotation in a certain offset direction can be obtained, and the universal effect is achieved. In particular, the welding installation process of the bendable structure 2 can realize welding points with different sizes in sequence to form different riveting forces (i.e. welding forces), and the bendable structure 2 has different flexibility from a far end to a near end, so that the bendable structure is suitable for more occasions.

It should be noted that, for a person skilled in the art, several modifications and additions can be made without departing from the method of the invention, which should also be considered as a protection scope of the invention. Those skilled in the art can make various changes, modifications and alterations without departing from the scope of the invention; meanwhile, any changes, modifications and variations of the above-described embodiments, which are equivalent to those of the technical spirit of the present invention, are within the scope of the technical solution of the present invention.

Claims

1. A bendable structure comprising a joint, said joint comprising two loop pieces; each ring piece is provided with at least two opposite convex parts and at least two opposite concave parts; the convex parts and the concave parts are arranged at intervals along the circumferential direction of the ring piece; the convex part and the concave part respectively protrude along different axial directions of the ring piece; the convex part and the concave part are connected through a curved surface; two of the ring pieces in the joint are connected by the convex part or the concave part.

2. A bendable structure according to claim 1, wherein two of the loop pieces in the joint are arranged mirror symmetrically in an axial direction of the bendable structure.

3. A bendable structure according to claim 1 or 2, wherein the loop width of the loop sheet is 5 to 10 times the thickness of the loop sheet.

4. A bendable structure according to claim 3, wherein the thickness of the loop sheet is no more than 0.3mm.

5. The bendable structure according to claim 1 or 2, wherein the ring piece has an even number of the convex portions, and the number of the concave portions coincides with the number of the convex portions.

6. The bendable structure according to claim 1 or 2, wherein the bendable structure is formed by connecting a plurality of the joints in order in an axial direction of the bendable structure.

7. A bendable structure according to claim 6, wherein the flexibility of the bendable structure in the axial direction is not the same.

8. The bendable structure of claim 7, wherein the flexibility of the plurality of joints decreases gradually from the distal end to the proximal end in the axial direction of the bendable structure.

9. A bendable structure according to claim 7, wherein a plurality of the ring segments are welded in series in an axial direction of the bendable structure.

10. A flexible instrument comprising a main body and a bendable structure according to any one of claims 1-9 disposed at a distal end of the main body.

11. The flexible instrument of claim 10 further comprising a positioning sleeve that is wrapped over the bendable structure.

12. The flexible instrument of claim 10 or 11 further comprising a pulling member having a distal end fixedly attached to the distal end of the bendable structure, the proximal end of the pulling member passing through all of the loop segments in sequence.

13. An endoscope, characterized in that a flexible instrument according to any one of claims 10-12 is used.