Endoscope having bending section controlled by control wire

Abstract

An endoscope (1) having a curved section (20) comprising segments (22) connected to each other by a hinge (24) is disclosed. The curved section has a central passage (12) passing through each segment (22) and extending from a distal end to a proximal end with the inner surface facing and surrounding the central passage (12). At least two grooves (18) into the inner surface extend parallel to and in open connection with the central passage (12). Two control wires (25) pass through the curved section in respective ones of the grooves. The anchor (15, 15 ', 15' ') is provided with a retaining portion (17, 17') such that displacement of the control wire (25) from the groove (18) towards the center of the central passage (12) is blocked.

Description

Technical Field

[0001] The present disclosure relates to an endoscope including an insertion cord including a bending section. The bending of the bending section is controlled by a steering wire extending in a dedicated portion of the bending section. Background Art

[0002] Flexible endoscopes for medical purposes are usually provided with a bending section at the distal end of the insertion tube. This enables the user of the endoscope to manipulate the distal end of the endoscope inside the human anatomy (such as in the airway, in the kidney or the gastrointestinal system), and for example to study or perform surgery at the tissue of interest. Typically, the bending section is bent by pulling the steering wire. If the endoscope is a two-way bending endoscope, that is, bending in two opposite directions but in the same plane, the bending section will typically be controlled by two steering wires, which are controlled by a steering wire actuator arranged in the handle of the endoscope, thereby allowing the user to bend the bending section by adjusting the bending rod. If the endoscope is a four-way bending endoscope, that is, bending in two opposite directions in addition, in a second plane perpendicular to the first plane mentioned, the bending section will typically be controlled by four steering wires, one of which controls the two steering wires for bending in the first plane, and another steering wire actuator controls the other two steering wires for bending in the second plane. Typically, each steering wire actuator is controlled by a rotating wheel on the handle of the endoscope.

[0003] The steering wires will go from the handle to the proximal end of the curved section inside the wire ducts, which are tubes with limited compressibility. Thus forming a so-called Bowden cable. The wire ducts are connected inside the handle at their proximal end. At the distal end of the wire ducts, these wire ducts are connected to the proximal end of the curved section, while the steering wires usually continue through the curved section in a dedicated lumen. The wire ducts are kept stationary and the translational movement of the steering wires at the proximal end is transmitted to the distal end as a corresponding translational movement of the steering wire relative to the wire duct.

[0004] For disposable endoscopes, the curved section may be molded in one piece from a polymer material. This molding process may be difficult, especially for narrow curved sections of the endoscope where the outer diameter is small. For example, for ureteroscopes, which typically have a relatively long curved section with an outer diameter that may be less than 3 mm, it may be difficult to make and find space for a closed lumen for a steering wire. In particular, the long and thin core required for the steering wire lumen will be fragile during the molding process and may cause frequent interruptions to the molding process.

[0005] It is simpler to make a curved section with only one internal lumen with a groove or recess, which serves as a passage for the steering wire. Such a groove is in open connection with the rest of the lumen. An example of this can be found in EP 3 925 513 A1. However, this design of a curved section does involve a slight risk that the steering wire may be displaced from the dedicated passage during an operation involving a specific manipulation (e.g., inside the kidney). Such a manipulation may be that the proximal end of the curved section is bent in one direction, and the operator of the endoscope manipulates the steering wire actuator to bend the distal end of the curved section in the opposite direction. Summary of the invention

[0006] The object of the present disclosure is to solve the above problems by providing an endoscope comprising a curved section having an inner lumen extending in a longitudinal direction. Grooves extend from the inner lumen and steering wires are arranged in the grooves. Anchors are placed so that the steering wires are prevented from shifting out of the grooves.

[0007] The endoscope may have a curved section comprising segments connected to each other by hinges. The curved section has a central passage that passes through each segment and extends from the distal end to the proximal end, wherein the inner surface faces and surrounds the central passage. At least two grooves entering the inner surface extend parallel to the central passage and are in open connection with the central passage. Two steering wires pass through the curved section in corresponding grooves in these grooves. The anchor is provided with a retaining portion so that the steering wire is blocked from shifting from the groove toward the center of the central passage.

[0008] The endoscope may include a handle and an insertion cord extending from the handle and including a curved section, for example molded in one piece from a molten polymer, the curved section including:

[0009] - Segments connected to each other by hinges, the hinges allowing two adjacent segments to bend relative to each other in a bending plane, the segments and the hinges forming the outer surface of the bending section.

[0010] - A central passage passing through each segment and extending from the distal end to the proximal end of the curved section, wherein each segment has a circumferential wall with an inner surface facing and surrounding the central passage.

[0011] - at least two grooves extending from the inner surface into the circumferential wall, the grooves extending parallel to and in open connection with the central passage, the central passage and the grooves extending through the segment of the curved segment. The grooves may be cutouts in the inner surface of the circumferential wall of the segment, but may not extend all the way in the longitudinal direction of the curved segment, as there may be no grooves or cutouts in the portion where the hinge connects two adjacent segments.

[0012] A recess extending from the outer surface into at least one segment or in at least one hinge.

[0013] The endoscope further comprises two steering wires extending from the handle to the distal end of the curved section, each steering wire passing through the curved section in a corresponding groove in the grooves. Further, an anchor is arranged in the notch, and the anchor is provided with a retaining portion so as to prevent the steering wire from being displaced from the groove toward the center of the central passage.

[0014] An advantage of the one or more anchors is that they enable the endoscope to be molded in one piece and have a small outer diameter curved section with an internal lumen, wherein the risk of manipulation wire displacement during endoscopic surgery is eliminated or at least reduced.

[0015] In a variation of this embodiment, anchors are placed only on the first 60% of the curved segment (i.e., 60% of the length of the curved segment starting from the proximal end of the curved segment and extending toward the distal end of the curved segment), in appropriate positions in at least two notches in the segment, or next to the segment. It has been found that it is advantageous to place the anchor in this first proximal portion of the curved segment because it has been found that the force on the steering wire in the direction toward the center of the central passage of the curved segment is greatest in this first proximal portion. Generally, it is also preferred to keep the total number of anchors low to keep manufacturing costs as low as possible. Preferably, the anchors should be applied to or combined with less than half of the segments. Preferably, the anchors should be applied to or combined with less than one-third of the segments. In a further variation, anchors are arranged in at least two segments, and anchors are arranged in less than 40% of the segments, alternatively in less than 30% of the segments.

[0016] In a variation of this embodiment, at least two segments are provided with anchors, so that displacement of the two steering wires is blocked. Having the anchors within the segments provides a very stable positioning of the anchors.

[0017] In a variation of this embodiment, at least two segments provided with anchors are separated by at least one segment without anchors. It has been found that this provides a good compromise between manufacturing costs and stability of the curved section, ensuring that the steering wires do not shift, leaving the anchors spread out rather than in adjacent segments. In a further variation, there may be at least two segments provided with anchors, separated by at least two segments without anchors.

[0018] In a variation of this embodiment, each anchor has a retaining portion extending into the space where the groove meets the central passage. The retaining portion has the advantage of providing a direct stop to prevent displacement of the steering wire.

[0019] In a variation of this embodiment, the steering wire in the curved section is passed inside the coil spring, the coil spring with the steering wire is each arranged in a groove, and the anchor is arranged to block the coil spring and thereby block the steering wire from shifting from the groove toward the center of the central passage. This reduces the risk of the steering wire moving into the narrow space between the working channel and the inner surface of the curved section, especially in the portion of the curved section without the anchor.

[0020] In a variation of this embodiment, the anchor has an outer surface flush with the outer surface of the segment, and the anchor has an inner surface flush with the inner surface. This allows the anchor to be of sufficient size to provide sufficient mechanical strength to resist the forces from the steering wire (eg, via a coil spring).

[0021] In a variation of this embodiment, the anchors are made of hardened glue. This enables simple and cost-effective manufacture of the endoscope, and it has also been found that very stable and efficient anchors are obtained. In a further variation, each anchor is adhered to a segment of the curved section.

[0022] In a variation of this embodiment, a projection extends from the segment, between the recess and the central passage, the projection supporting the anchor. This provides a firm and stable support, in particular for the glue anchor variation.

[0023] In a variation of this embodiment, the anchor is made of a metal disk. This provides an anchor that takes up a minimal amount of space in the proximal to distal length direction of the curved section.

[0024] In a second aspect, the present disclosure relates to a method for assembling an endoscope, the method comprising:

[0025] - providing a curved section, the curved section being molded in one piece from a molten polymer and having:

[0026] o segments connected to each other by hinge members, the hinge allowing two adjacent segments to bend relative to each other in a bending plane, the segments and the hinge forming the outer surface of the bending segment,

[0027] o a central passageway passing through each segment and extending from a distal end to a proximal end of the curved segment, wherein each segment has a circumferential wall having an inner surface facing and surrounding the central passageway,

[0028] o at least two grooves extending from the inner surface into the circumferential wall, the grooves extending parallel to the central passage and in open connection with the central passage, the central passage and the grooves extending through a segment of the curved section,

[0029] o a notch extending from the outer surface into at least one segment or into at least one hinge;

[0030] - arranging two steering wires to extend from the handle to the distal end of the curved section so that each steering wire passes through the curved section in a separate groove;

[0031] - Arranging an anchor in the recess, wherein the anchor is provided with a retaining portion such that a displacement of the steering wire from the recess towards the centre of the central passage is blocked.

[0032] The method has been found to be a cost effective way to manufacture curved sections for endoscopes having small diameter insertion wires, such as disposable endoscopes.The outer diameter of the insertion wire (including the curved section) may be 3 mm or less.

[0033] A third aspect of the present disclosure relates to a system comprising a monitor, a control unit and an endoscope according to the first aspect and its variations.

[0034] The segments of the curved section include a proximal segment, a distal segment, and an intermediate segment arranged between the proximal segment and the distal segment. The segments are not necessarily the same. In particular, the proximal segment and the distal segment may have features that can connect the curved section to the insertion tube and the distal end housing, respectively.

[0035] In this disclosure, the expression "distal" is defined as the direction toward the patient, and "proximal" is defined as the direction away from the patient. For the handle of the endoscope, the distal end is the end connected to the insertion tube, and the proximal end is the opposite end. Further, the expression "handle" can be a positioning interface or interface for controlling the position of the insertion cord and operating the bending section. The handle or positioning interface can be an interface operated by a robotic arm, or can be a handle operated by the hand of the endoscope user.

[0036] For the purposes of this disclosure, one steering wire is considered to be one passage from the steering wire actuator (or roller) to the distal end of the bending section. That is, if the same unbroken steering wire continues from the steering wire actuator to the distal end of the bending section and back to the steering wire actuator, and a portion is used, for example, to bend to one side and another portion is used to bend to the opposite side, then this is considered to be two steering wires, for example, a first steering wire and a second steering wire.

[0037] The anchors arranged in combination with the segments can hold two steering wires inside the grooves, or the anchors in the segments can only hold one steering wire in the corresponding groove. In the latter case, it may be preferred to have the two anchors in the same segment, but it is also possible to place anchors for two different steering wires in different segments. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The above-described embodiments and their variations, features and advantages will be further clarified by the following illustrative and non-limiting detailed description of the embodiments disclosed herein with reference to the accompanying drawings, in which:

[0039] Figure 1 An endoscope and a monitor with a control unit are shown.

[0040] Figure 2 An example of a steering wire actuator (here in the form of a roller) and a wire conduit fastener is shown.

[0041] Figure 3 The distal end of the endoscope including the curved section is shown.

[0042] Figure 4 A cross-sectional view of a curved section provided with glue anchors is shown.

[0043] Figure 5 A portion of a curved section is shown, in which one segment is provided with an anchor.

[0044] Figure 6 Shown from different angles Figure 5 of the curved section.

[0045] Figure 7 A portion of a curved section with a disc anchor is shown.

[0046] Figure 8 An example of a separate disc anchor is shown.

[0047] Fig. 9 Shows that there is Figure 8 A cutaway curved section of a disc anchor.

[0048] Fig.10 A portion of a curved section with different disc anchors is shown.

[0049] Fig.11 A portion of a curved section is shown with some segments removed to better view the disc anchor.

[0050] Fig.12 Shows that there is Fig.10 Cross-sectional view of a curved section of a disc anchor.

[0051] Fig.13 Shows Figures 10 to 12 The disc anchor included.

[0052] Fig.14 The S-shaped curvature of the curved section is schematically illustrated.

[0053] In the drawings, corresponding reference numerals indicate corresponding parts, functions, and features throughout the several views. The drawings are not necessarily drawn to scale, and certain features may be exaggerated to better illustrate and explain the disclosed embodiments. For simplicity, the present disclosure will focus on two-way bending endoscopes, but the present disclosure is also relevant to and covers four-way bending endoscopes. DETAILED DESCRIPTION

[0054] Figure 1 An endoscope 1 is shown, which includes: a handle 2; an insertion cord 3; and an electrical cable having a connector 4 for connecting the endoscope 1 to a monitor 41. The insertion cord 3 is the portion inserted into a body cavity during endoscopic surgery. The insertion cord includes a distal tip 10, a bending section 20, and a main tube 5. The handle 2 may include an entrance to a working channel 6 that extends through the insertion cord to the distal tip. The handle also includes a bending rod 46 that can be used to bend the bending section.

[0055] Distal tip 10 includes a camera and a light emitter (eg, in the form of one or more LEDs or the end of an optical fiber).

[0056] The monitor 41 may be combined with an electronic circuit for receiving and processing an image stream from a camera and a processor for image processing, user interface, image storage, etc. However, the monitor portion and the electronic circuit and processor portion may also be separate portions. The electronic circuit and processor portion is also referred to as a control unit 42.

[0057] Figure 2 A schematic example of a roller 32 of a control wire actuator 60 is shown, which is configured to bend the bending section by pulling the control wire 25. The control wire 25 is moved by the rotation of the wire barrel bending surface 61, which is an arc surface or a curved surface placed on the roller 32 and supporting the control wires. In the example, one end of the control wire is pulled by the fixing structure 62 and bent back and fastened to itself by a crimping piece 63. The proximal end of the wire conduit 26 is fixed in the wire conduit fastener 70, and the distal end of the wire conduit is fixed to the proximal end of the bending section 20. The wire conduit fastener 70 and the roller 32 are usually fixed in the handle 2. Figure 2 The system in is used for bidirectional curved endoscopes.

[0058] Figure 3The distal end of the insertion cord 3 of the endoscope is shown with a bend cover (not shown) removed which typically covers part of the bend section 20 and generally makes the section waterproof. The proximal end of the bend section is attached to the main tube 5 and the distal end of the bend section is attached to the distal tip 10. In this example, the bend section is molded in one piece and includes several segments 22. The proximal segment 22' is connected to the distal end of the main tube 5. The distal segment 22" is connected to the distal tip 10. The segments are held together by hinges 24 so that the segments can be bent relative to each other by manipulation of the steering wire 25. An example of such a bend section molded in one piece can be seen in EP 3 925 513 A1, the entire contents of which are incorporated herein by reference.

[0059] Alternatively, the curved section 20 may be extruded from a relatively soft and resilient material (eg, a foam-like material) with a lumen through which steering wires, electrical wires, and tubes pass.

[0060] The control wire 25 is connected to the distal end (e.g., the distal curved segment 21) in a fixed connection. That is, the control wire is preferably not movable relative to the distal curved segment. Between the handle and the distal end of the main tube 5, or the proximal end of the curved section 20, the control wire 25 is guided in a wire conduit 26 that is fixed in the handle 2, distal to the control wire actuator 60. Other designs of the curved section are also possible.

[0061] Figures 4 to 6 An embodiment of a bending section 20 for an endoscope 1 is shown, wherein the bending section 20 is provided with only one internal lumen or central passage 12. The central passage 12 has grooves 18 or recesses that are openly connected to the rest of the central passage 12. Steering wires 25 are arranged in these grooves 18. Anchors 15 are provided to prevent the steering wires 25 from being displaced from or leaving the grooves 18 during the bending operation. Figure 4 The cross-sectional view in Figure 5 The glue anchor 15 and the notch 14 are formed at the locations thereof.

[0062] Figures 4 to 6 The anchor 15 shown may be made of a hardened adhesive that fills the recess 14 made in the segment 22 . Figure 4 A cross-sectional view of a segment 22 is shown, in which two recesses 14 have been made. The recesses have been filled with glue or adhesive, which has hardened, thereby forming anchors 15. Figure 5 The curved section 20 is shown from one side, whereby a recess 14 can be seen in the segment 22. An anchor 15 made of hardened transparent glue is placed in this recess 14. Figure 4It is shown that similar anchors 15 may be placed on opposite sides of the curved section 20. There is one anchor for each steering wire 25.

[0063] The anchor 15 has retaining portions 17 extending into the space between the steering wire 25 and the working channel 6. These retaining portions 17 of the anchor prevent the steering wire 25 from being displaced in the direction towards the working channel 6.

[0064] exist Figures 4 to 6 18 shows that the steering wire in the curved section can be arranged inside the coil spring 27. The coil spring 27 with the steering wire 25 is each arranged in a groove 18, and the anchor 15 is arranged to block the coil spring 27 and thereby block the steering wire 25 from shifting from the groove 18 toward the center of the central passage 12. This reduces the risk of the steering wire moving into the narrow space between the working channel 6 and the inner surface of the curved section 20. This can be advantageous for the segment 22 where the anchor 15 is not arranged. If the spring 27 is part of the design, the retaining part 17 of the anchor will extend into the space between the spring 27 and the working channel 6.

[0065] The use of a spring 27 to guide or enclose a steering wire through a curved section, wherein a groove 18 (i.e., a dedicated lumen for the steering wire) is in open connection with a lumen for a working channel, is further described in EP 4 035 584 A1, the entire contents of which are incorporated herein by reference, and is used for a bidirectional bending endoscope.

[0066] The spring 27 is made of a winding wire (e.g., a steel wire). The distance between two adjacent windings of the spring 27 can be referred to as the pitch of the spring 27. Therefore, the minimum pitch is approximately the diameter of the wire used for the spring. The pitch should be selected so that the spring can be compressed and extended during the bending of the bending section. The pitch can also be varied so that the pitch is smaller in the segment where the anchor 15 is placed and larger in other locations. A small pitch can prevent liquid glue from entering between the windings and adhering to the steering wire during the gluing process of providing the gluing anchor. The pitch can be at a minimum value at the location where the anchor is to be placed. However, if the liquid glue has a high viscosity, the pitch can be greater than the minimum value and still prevent the glue from contacting the steering wire.

[0067] Alternatively, the control wire 25 can be arranged to be movably passed through the anchor 15 without the spring 27. In this case, it must be ensured during manufacturing that there is no adhesion between the control wire and the anchor. This can be ensured by applying a lubricant to the control wire 25. The lubricant can be applied before the application and hardening of the glue. The glue and the control wire material can also be selected so that there will be no adhesion. In this case, a lubricant may not be necessary, but may still be advantageous for reducing the friction between the control wire and the hardened glue.

[0068] Compared to the size of the retaining portion 17 which actively retains the control wire in the groove 18, Figures 4 to 6 The anchor 15 shown is relatively large. One reason for this is that the bending section 20, which is molded in one piece from a polymer material, is typically made of POM, and most glues do not adhere well to POM. Therefore, the geometry of the anchor 15, which is made of hardened glue, can be such that the anchor is held in the correct position in the recess 14 of the segment 22, even when the glue does not adhere to the bending section material. This can be achieved by a protrusion 16 extending between a portion of the anchor 15 and the working channel 6. The protrusion 16 can be formed in one piece with the rest of the segment and the bending section, and can be molded from the same molten polymer material. The protrusion 16 can therefore support the anchor 15 and be adapted to hold the anchor 15 in the correct position.

[0069] Also, to the extent that there is some adhesion between the curved section material and the glue anchor 15, increasing the contact area between the two (which is also accomplished by the protrusions 16) will increase the stability of the anchor position.

[0070] For glue anchors, the notch may be located in a segment, wherein the segment bounds the notch both in the distal direction and in the proximal direction. This may make it easier to control where the glue flows during the gluing process.

[0071] It should be noted that the curved section 20 may typically be provided with a curved cover 21 on the outside. This provides a waterproof barrier towards the surrounding environment of the endoscope insertion cord 3. This curved cover 21 may have a certain effect on supporting the anchor 15 in the correct position. However, this effect may be relatively small because the curved cover is typically very flexible and nothing is glued to the curved cover.

[0072] For glue anchors, a UV curing glue can be applied because curing can occur immediately and thereby limit the time so that the glue cannot flow into undesired locations inside the curved section. The glue for the anchor 15 can be applied from the outside of the curved section 20, for example, using a small needle tip for precise application. The viscosity of the glue can be selected to be low enough so that the glue flows between the steering wire 25 and the working channel 6 to form the retaining portion 17. Moreover, the viscosity of the glue can be selected to be high enough to avoid the glue from flowing into undesired portions of the curved section via capillary forces. Moreover, it may be easier to form a smooth surface on the outside of the anchor 15 (i.e., the outside of the curved section) with a higher viscosity glue having a higher surface tension.

[0073] Figures 7 to 12 An embodiment is shown in which the anchor 15' is made of a disk 35. The disk may be shaped like the Greek letter Ω, a horseshoe or a U. The disk is arranged in the recess 14, wherein the recess may be in the segment 22 (e.g. Fig.10 and Fig.11 ), or the notch may be in the hinge 24 connecting the two segments 22 (as shown Figure 7 and Fig. 9 Preferably, the disc 35 may include an anchor portion 15 ′ for both of the two steering wires, or alternatively, the disc 35 may have an anchor portion for only one of the steering wires 25 .

[0074] The disk 35 is preferably made of a hard material, such as a metal such as steel. The disk may also be made of a relatively hard polymer, such as PC, PS, PA. The thickness of the disk may depend on the material. For steel, the thickness may be in the range of 0.1 mm to 0.5 mm, preferably 0.1 mm to 0.3 mm. If the material is a polymer, the thickness may be greater than 0.3 mm.

[0075] The disc 35 may be shaped so that its outer circumference 36 is flush with the outer surface formed by the curved section segments 22 and the portion of the hinge 24 facing away from the central passage 12 of the curved section 20. In this embodiment, this outer surface may also be covered by the curved cover 21.

[0076] The disk 35 is provided with a retaining portion 17 ′ which extends into the space between the control wire 25 and the working channel 6 so that a displacement of the control wire 25 and possibly also the spring 27 in the direction towards the working channel 6 or the center of the central passage is prevented.

[0077] When the disc 35 is arranged in the notch 14 in the hinge 24, this may limit the angle to which two adjacent segments next to the hinge can bend relative to each other. For some applications of the endoscope, this limitation may be acceptable. If the bending section is provided with many hinges (e.g., 20 or more hinges), it is possible that this limited bendability of two pairs of hinges may not significantly affect the overall bending performance.

[0078] Figure 8 and Fig. 9 A variant of the embodiment is shown in which the anchor 15' is a disc 35. In this variant, the passages 37 for the steering wires (and for example also for the springs) are provided as closed holes. This means that the steering wires and for example the springs will need to pass through these holes.

[0079] Alternatively, in Figures 10 to 13 , another variant of an anchor 15 ″ arranged as a disc 35 is shown. In this variant, the passage 37 ′ is not closed, but open at one side, so that the disc 35 can be inserted into the recess 14 after the control wire 25 and, for example, the spring 27 have been arranged in the groove for the control wire 25 and, for example, the spring 27. In this variant, the recess is preferably made in the segment 22 of the curved section.

[0080] Different types of anchors may be combined at different locations in the same curved section.The anchors may generally be the examples provided above, but may also be other types or designs of anchors.

[0081] The number of anchors and their position along the proximal-distal direction of the curved segment can depend on the total length of the curved segment, the outer diameter of the curved segment, the maximum bending angle of the distal end of the curved segment relative to the proximal end of the curved segment, and the tension required on the steering wire to obtain this bending angle.

[0082] For example, a ureteroscope may have a curved section that is greater than 35 mm in length, and possibly greater than 45 mm. The outer diameter may be about 3 mm or less. The maximum bend angle may be about 270 degrees, and may be in the range of 225 to 270 degrees. When using a ureteroscope in renal surgery, it may often happen that the curved section has a first curvature 38 extending in one direction in the proximal half of the length of the curved section, and at the same time it is desired to bend the distal end of the curved section in the opposite direction, resulting in a second curvature 39. This may be particularly useful in renal surgery. Fig.14 It is schematically shown in , where the resulting S-shaped curvature of the curved section can be seen.

[0083] This means that there will be a relatively large force on the steering wire 25 on the convex side of the first curvature 38 or proximal bending curve because the steering wire 25 needs to be pulled to bend the distal end of the curved section into the second curvature 39. This force is directed toward the center of the central passage of the curved section. Generally, the force on the steering wire 25 will tend to move the steering wire toward line AB. Circle c represents the area where the force toward line AB is the greatest for the steering wire 25. Therefore, the anchor 15, 15', 15" can be placed in the following part of the curved section: where this area is likely to have the greatest force during surgery.

[0084] Check Fig.14 39, recognizing that the other steering wire 25' placed to the concave side of the first curvature 38 will be affected by relatively less force because it does not have to be pulled to bend the distal end of the curved segment into the second curvature 39. Moreover, the forces on the other steering wire 25' in the first curvature 38 are directed toward the groove 18 and the circumferential wall 23 of the segment 22, which will be more resistant to any accidental displacement of the steering wire than the working channel 6.

[0085] The above-described embodiments or variations of the anchors and how the anchors are arranged and connected to the curved sections do not limit the scope of the present disclosure. Other designs, arrangements and connections of the anchors are possible within the scope of the claims.

[0086] List of Reference Numerals

[0087] 1 Endoscope 23 Circumferential wall

[0088] 2 Handle 24 Hinge

[0089] 3 Insert the flexible wire 25, 25' control wire

[0090] 4 Cables with plugs 26-wire conduit

[0091] 5 Main pipe 27 Spring

[0092] 6 working channels 32 rollers

[0093] 7 Wire harness 35, 35' tray

[0094] 10 Distal end 36 Outer circumference

[0095] 12 Central passage 37, 37' passage

[0096] 14 Notch 38 First curvature

[0097] 15, 15', 15" Anchor 39 Second Curvature

[0098] 16 protrusion for supporting the anchor 41 monitor

[0099] 17, 17' holding part 42 control unit

[0100] 18 groove 46 bent rod

[0101] 20 bending section 60 control line actuator

[0102] 21 curved cover 61 curved surface of wire barrel

[0103] 22 Segment 62 Fixed structure

[0104] 22' Proximal segment 63 Crimp

[0105] 22” Distal Segment 70 Wire Pipe Fastener.

Claims

1. An endoscope, comprising: -handle; - an insertion cord extending from the handle and comprising a curved section molded in one piece, the curved section comprising: i. segments connected to each other by hinges, which allow two adjacent segments to bend relative to each other in a bending plane, the segments and the hinges forming the outer surface of the bending segment, ii. a central passageway passing through each segment and extending from the distal end to the proximal end of the curved segment, wherein each segment has a circumferential wall having an inner surface facing and surrounding the central passageway, iii. at least two grooves extending from the inner surface into the circumferential wall, the grooves extending parallel to and in open connection with the central passage, the central passage and the grooves extending through a segment of the curved section, iv. a notch extending from the outer surface into at least one segment or in at least one hinge; - two steering wires extending from the handle to the distal end of the curved section, each steering wire passing through the curved section in a corresponding one of the grooves; Therein, an anchor is arranged in the recess, the anchor being provided with a retaining portion so that the steering wires are blocked from being displaced from the grooves toward the center of the central passage.

2. The endoscope according to claim 1, wherein: Anchors are placed in at least two notches in the segment or immediately adjacent to the segment over 60% of the length of the curved segment extending from the proximal end toward the distal end of the curved segment.

3. The endoscope according to claim 2, wherein: At least two segments are provided with anchors so that displacement of the two steering wires is blocked.

4. The endoscope according to claim 2 or 3, wherein: At least two segments provided with anchors are separated by at least one segment without anchors.

5. The endoscope according to claim 1, wherein: Each anchor has a retaining portion that extends into the space where the groove meets the central passageway.

6. The endoscope according to claim 1, wherein: The steering wires in the curved section pass inside coil springs, the coil springs with the steering wires are each arranged in a groove, and the anchor is arranged to block the coil springs and thereby the steering wires from shifting from the grooves towards the center of the central passage.

7. The endoscope according to claim 1, wherein: The anchors have an outer surface that is flush with the outer surface of the segment, and the anchors have an inner surface that is flush with the inner surface.

8. The endoscope according to claim 1, wherein: These anchors are made of hardened glue.

9. The endoscope according to claim 8, wherein: A protrusion extends from the segment between the recess and the central passage, the protrusion supporting the anchor.

10. The endoscope according to claim 1, wherein: These anchors are made of metal discs.

11. The endoscope according to claim 1, wherein: Anchors are arranged in at least two segments, and anchors are arranged in less than 40% of the segments, alternatively anchors are arranged in less than 30% of the segments.

12. A method for assembling an endoscope according to any one of the preceding claims, the method comprising: - providing a curved section, the curved section being molded in one piece from a molten polymer and having: i. segments connected to each other by hinge members, the hinges allowing two adjacent segments to bend relative to each other in a bending plane, the segments and the hinges forming the outer surface of the bending segment, ii. a central passageway passing through each segment and extending from the distal end to the proximal end of the curved segment, wherein each segment has a circumferential wall having an inner surface facing and surrounding the central passageway, iii. at least two grooves extending from the inner surface into the circumferential wall, the grooves extending parallel to and in open connection with the central passage, the central passage and the grooves extending through a segment of the curved section, iv. a notch extending from the outer surface into at least one segment or in at least one hinge; - arranging two steering wires to extend from the handle to the distal end of the curved section so that each steering wire passes through the curved section in a corresponding one of the grooves; - Arranging an anchor in the recess, wherein the anchor is provided with a retaining portion such that a displacement of the steering wires from the grooves towards the centre of the central passage is blocked.

13. A system comprising a monitor, a control unit and an endoscope according to any one of claims 1 to 11.

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