REINFORCED WORKING CHANNEL TUBE

Abstract

A working channel tube and a method for producing the working channel tube, the method including providing a tube reinforced with a wire coiled and embedded between an inner and outer surface of the tube, a non-embedded wire portion of the wire extending from an exit point; bending the non-embedded wire portion at a rotation location forming a bend, a first non-embedded wire sub portion and a second non-embedded wire sub portion; extending the second non-embedded wire sub portion back across the tube to a clamping location; clamping the second non-embedded wire sub portion at the clamping location in a clamp; and rotating the non-embedded wire sub portions at the rotation location such that the first and second non-embedded wire sub portions twist around each other until the wire breaks. Moreover, a working channel tube produced by said method, and an endoscope comprising said working channel tube are disclosed.

Claims

1. A method of making a working channel tube for an endoscope, the method comprising: providing a tube reinforced with a wire embedded between an inner surface and an outer surface of the tube, a non-embedded wire portion of the wire extending, at an exit point, from the outer surface, an embedded wire portion of the wire extending, from the exit point, beneath the inner surface; fixating the working channel tube in a releasable manner to a support structure; bending the non-embedded wire portion at a distance from the exit point to form a bend, a first non-embedded wire sub portion extending from the exit point to the bend, and a second non-embedded wire sub portion extending from the bend; extending the second non-embedded wire sub portion from the bend across the working channel tube; and twisting together the first non-embedded wire sub portion and the second non-embedded wire sub portion until the wire breaks, wherein the wire breaks at the exit point or beneath the outer surface without protruding from the outer surface.

2. The method of claim 1, the method further comprising, prior to said twisting, securing the the second non-embedded wire sub portion at a securing point, the second non-embedded wire sub portion thus extending from the bend across the tube to the securing point at an angle less than 45 degrees to line normal to a longitudinal axis of the tube.

3. The method of claim 1, the method further comprising, while twisting, tensioning the second non-embedded wire sub portion less than the first non-embedded wire sub portion.

4. The method of claim 1, wherein the method further comprises: prior to said twisting, securing the the second non-embedded wire sub portion at a securement means, the second non-embedded wire sub portion thus extending from the bend across the working channel tube to the securing point at an angle less than 45 degrees to a line normal to a longitudinal axis of the working channel tube, said securing allowing the second non-embedded wire sub portion to slip through the securement means; said twisting causing tensioning the first non-embedded wire sub portion and the second non-embedded wire sub portion; and said securing of the second non-embedded wire sub portion allowing the second non-embedded wire sub portion to slip and thus maintain a tension in the the second non-embedded wire sub portion lower than a tension in the first non-embedded wire sub portion.

5. A method of making a working channel tube for an endoscope, the method comprising: a) providing a tube reinforced with a wire that is coiled and embedded between an inner surface and an outer surface of the tube, wherein a non-embedded wire portion of the wire extends out of the outer surface of the working channel tube from an exit point, wherein an exit point tangent line that is tangent to the outer surface at the exit point defines two opposite directions extending away from the exit point: i. an unembedded direction extending away from a final embedded wire portion leading up to the exit point; and ii. an embedded direction that is opposite the unembedded direction; wherein an exit plane extends through the exit point and a longitudinal axis of the working channel tube, the space extending in the unembedded and embedded directions from the exit plane being defined as the unembedded space and embedded space, respectively; b) fixating the tube; c) extending the non-embedded wire portion from the exit point to a rotation location located in the unembedded space; d) bending the non-embedded wire portion at the rotation location forming a bend, a first non-embedded wire sub portion extending from the exit point to the bend, and a second non-embedded wire sub portion extending after the bend; e) extending the second non-embedded wire sub portion across the tube to a clamping location located in the embedded space; f) clamping the second non-embedded wire sub portion at the clamping location in a clamp; and g) rotating the first non-embedded wire sub portion and the second non-embedded wire sub portion at the rotation location to twist the first and second non-embedded wire sub portions around each other until the wire breaks.

6. The method of claim 5, wherein the clamp is configured to allow slippage of the wire when the wire is pulled, wherein the rotation location is located in the unembedded space such that a rotation angle in a direction normal to the exit point and the tube outer surface between a straight line extending from the exit point to the rotation location and the exit point tangent line is 45 degrees or less, and wherein the clamping location is located in the embedded space such that a clamping angle between the exit point tangent line and a straight line extending from the exit point to the clamping location is 45 degrees or less.

7. The method of claim 5, wherein the clamp is configured to allow slippage of the wire when the wire is pulled.

8. The method of claim 5, wherein the rotation location is located in the unembedded space such that a rotation angle in a direction normal to the exit point and the tube outer surface between a straight line extending from the exit point to the rotation location and the exit point tangent line is 45 degrees or less.

9. The method of claim 5, wherein the clamping location is located in the embedded space such that a clamping angle between the exit point tangent line and a straight line extending from the exit point to the clamping location is 45 degrees or less.

10. The method of claim 5, wherein there is a distance of 0.5 or more, but equal to or less than 10, tube outer diameters between the exit plane and the rotation location and between the exit plane and the clamping location, respectively, the distance being measured perpendicularly to the exit plane.

11. The method of claim 10, wherein the tube is fixated such that there is a fixation location within 10 or fewer tube outer diameters on both sides, longitudinally, of the exit point.

12. The method of claim 11, wherein a rod is inserted into the tube before fixating the tube in place, and wherein the rod is at least inserted a length such that it extends inside the tube to each fixation location.

13. The method of claim 5, wherein a rod is inserted into the tube before fixating the tube in place.

14. The method of claim 13, wherein the rod is at least inserted a length such that it extends inside the tube at each location the tube is fixated and/or at each exit point.

15. The method of claim 5, wherein a second non-embedded wire portion of the wire extends out of the outer surface of the tube from a different second exit point defining respective unembedded and embedded directions, wherein steps c) to g) are performed for the second non-embedded wire portion respectively.

16. The method of claim 15, wherein the wire is embedded and coiled between the exit point and the second exit point, a longitudinal distance between the exit point and the second exit point being equal to or less than three quarters of a length of the tube.

17. The method of claim 5, wherein at least an outer layer of the tube is made from a plastic material.

18. The method of claim 5, wherein the wire breaks at the exit point or beneath the outer surface such that the wire does not protrude from the outer surface.

19. A working channel tube made by the method of claim 5.

20. An endoscope comprising the working channel tube of claim 19.

21. A visualization system comprising a video processing apparatus and the endoscope of claim 20, wherein the video processing apparatus is couplable to the endoscope and capable of processing an image recorded by the endoscope and outputting the image on a display.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0057] The disclosure will now be made in greater detail based on non-limiting exemplary embodiments and with reference to the drawings, on which:

[0058] FIG. 1 shows a schematic view of a visualization system comprising an endoscope and a video processing apparatus according to the present disclosure.

[0059] FIG. 2 is a side view of a bending section showing a working channel tube.

[0060] FIG. 3 is cross-section A-A of the bending section of FIG. 2.

[0061] FIG. 4 shows a flow chart of a method for producing a reinforced working channel tube according to the present disclosure.

[0062] FIG. 5 shows a perspective view of a working channel tube in a wire breaking machine during production according to a method of the present disclosure.

[0063] FIG. 6 shows a close-up of the detail BB in FIG. 5.

[0064] FIG. 7 shows a schematic illustration of a working channel tube during production according to another variation of the method of the present disclosure viewed in parallel with the longitudinal axis of the tube.

[0065] FIG. 8 shows the same view of the schematic illustration of FIG. 7 in a state where the non-embedded wire sub portions have been rotated a certain amount.

[0066] FIG. 9 shows another variation of the method according to the present disclosure, from the same vantage point as in FIG. 7 and FIG. 8.

[0067] FIG. 10 shows a top-down view of a schematic illustration of a working channel tube during production according to another variation of the method according to the present disclosure.

[0068] FIG. 11 shows a cross-section through a working channel tube according to an embodiment of the present disclosure.

[0069] FIG. 12 shows a longitudinal sectional view of a working channel tube according to the present disclosure.

[0070] The figures are schematic in nature and serve only to understand the disclosure. The features of the different embodiments can be interchanged among each other.

DETAILED DESCRIPTION

[0071] FIG. 1 is a schematic side view of a visualization system 100 including an endoscope 2 with a cable connector 106, which can be connected to an endoscope connection port (not shown) of the video processing apparatus (VPA) 102. A VPA can incorporate a display screen 104 or, as shown, can be connected to a separable display screen. The VPA can be communicatively connected, as is known in the art, via an ethernet, wireless, AVI, HDMI, or other data interfaces to a separable display screen 104. Upon connection of the endoscope the VPA presents images or video streams with the display screen, as is known in the art. The endoscope 2 has a proximal endoscope handle 4 and an insertion cord 6 extending distally from the endoscope handle 4. The insertion cord 6 is configured to be inserted into a patient's body cavity and comprises an insertion tube 8, an actively bendable bending section 10 and a distal tip unit 12. The endoscope 2 further comprises a working channel 14 which extends from a working channel access port 16 provided at the endoscope handle 4 to the distal tip unit 12. The working channel 14 is comprised by a working channel tube 18, which is arranged inside the endoscope handle 4, the insertion tube 8 and the bending section 10. The endoscope handle 4 comprises two operating units 20, 22 formed as wheels for steering the bending section 10 of the insertion cord 6. In particular, a rotation force can be applied to both the first operating unit 20 and the second operating unit 22 by a user in order to bend the bending section 10 in two bending planes i.e. four directions. The endoscope 2 may alternatively be formed as a one-plane bending endoscope which can be bent only in two, preferably opposite, directions and which has only one operating unit 20, 22. In addition to wheels, operating units may comprise levers as are well known in the art. The endoscope may be a single-use endoscope.

[0072] FIG. 2 shows an embodiment of a bending section 10 showing a working channel tube 18 (the reinforcement is not shown). FIG. 3 is cross-section A-A of the bending section of FIG. 2 showing a spacing 70 in which the working channel tube 18 is positioned. The bending section 10 may comprise a single-piece polymeric structure comprising a plurality of segments 60 interconnected by polymeric strips 62, or hinges, which form part of the one-piece structure and bend upon tensioning of steering cables 64 by operation of the operating unit 20. The working channel 14 may be configured to introduce a surgical tool therethrough. In FIG. 3, a wall of the segment 60 defines the spacing 70 and a number of cut-out lobes 72 extending from the periphery of the inner surface of the segment 60 through which steering cable guide tubes 66 and the steering cables 64 pass. A sleeve (not shown) may be provided over the bending section 10 to fluidly seal the spaces between adjacent segments 60. Wires 68 pass through one of the cut-out lobes 72 and connect a camera positioned in the distal tip of the insertion cord 6 to the handle 4. A cable having a cable connector 106 connects the wires 68 to a VPA 102 shown in FIG. 1.

[0073] Space in the bending section is limited and becomes even more limited as the diameter of the insertion cord 6 is reduced to minimize the invasiveness of the surgical procedure in which the endoscope 2 is used. These reductions require smaller working channel tubes with smaller wall thicknesses, and the working channel tubes with reduced wall thickness benefit from the disclosed reinforcement. Any protrusions from the outer surface of the working channel tube, such as for example wire from a reinforcing wire coil, will reduce the gained benefit of using working channel tubes with smaller wall thicknesses as the protrusions will take up some or all of the space saved by using smaller wall thickness working channel tubes. Furthermore, such protrusions may create additional friction and resistance to bending and maneuvering the endoscope especially if they contact and catch on the inner surface of the insertion tube 8. If other fluid tubes are provided inside the insertion tube, particularly if they are made of a plastic, as may often be the case, such protrusions may catch on, damage, or even pierce these fluid tubes Therefore, any such protrusion should preferably be avoided.

[0074] The working channel tube 18 provided inside the endoscope handle 4, the insertion tube 8 and the bending section 10 is a specific reinforced working channel tube 18 according to the present disclosure and is in particular reinforced in a portion of the working channel tube 18 which is arranged inside of the bending section 10, in order to prevent kinking of the working channel tube 18 when the bending section 10 is bent. It is also possible to reinforce the entire working channel tube 18, i.e. not only the portion of the working channel tube 18 which is arranged inside the bending section 10 of the insertion cord 6, or other portions of the working channel tube 18. Further, the working channel tube 18 does not need to be arranged inside the insertion cord 6 but may, alternatively, be attached to the insertion cord 6 from outside.

[0075] With reference to FIGS. 4-10 a method for producing a wire coil reinforced working channel tube 18 for an endoscope according to the present disclosure will be described. FIG. 4 shows a flow chart of the method for producing a reinforced working channel tube 18. In a first step S1, a working channel tube 18 reinforced with a wire coil 33 that is embedded between an inner 26 and outer 28 surface of the working channel tube is provided. A non-embedded wire portion 30 of the wire coil 33 extends out of the outer surface 28 of the tube 18 from an exit point 29 and an exit point tangent line 34 that is tangent to the outer surface 28 at the exit point 29 defines two opposite directions extending away from the exit point 29, an unembedded direction UD extending away from a final embedded wire portion 35 leading up to the exit point 29, and an embedded direction ED that is opposite the unembedded direction UD as seen e.g. in FIG. 7. Further, an exit plane 36 extends through the exit point 29 and the longitudinal axis L of the tube 18, the space extending in the unembedded and embedded directions from the exit plane being defined as the unembedded space and embedded space, respectively.

[0076] In a step S2, the working channel tube 18 is fixated. The non-embedded wire portion 30 is then extended from the exit point 29 to a rotation location 40 in the unembedded space in a step S3. In a further step S4, the non-embedded wire portion 30 is bent at the rotation location 40 forming a bend 41 and a first non-embedded wire sub portion 31 extending from the exit point 29 to the bend 41 and a second non-embedded wire sub portion 32 extending after the bend 41. In a step S5 the second non-embedded wire sub portion 32 is extended back across the working channel tube 18 to a clamping location 42 located in the embedded space. In a step S6 the second non-embedded wire sub portion 32 is clamped at the clamping location 42 in a clamp configured to allow slippage of the wire 32 such that a length of the wire slides out of the clamp when pulled. In a step 7 the non-embedded wire sub portions 31, 32 are rotated at the rotation location 40 such that the first and second non-embedded wire sub portions 31, 32 twist around each other until wire breaks (twisting of the wires is shown in e.g. FIG. 8). The order of the steps described here is merely one example within the scope of this disclosure. In other variations of the present embodiment the order may be different, for example the non-embedded wire portion 30 may be bent before it is extended to the rotation location 40, the second non-embedded wire sub portion 32 may be extended across the tube 18 to the clamping location 42 and potentially clamped there before the non-embedded wire portion 30 is extended to the rotation location 40, the working channel tube 18 may be fixated after the non-embedded wire portion 30 has been bent at the rotation location 40 and/or after the second non-embedded wire sub portion 32 has been clamped at the clamping location 42.

[0077] As also mentioned in the summary section the wire coil reinforced working channel tube 18 may be provided in a variety of perceivable ways as is known to the person skilled in the art. In this example it is provided by providing a working channel tube made from a plastic material, softening the outer surface 28 of the tube 18 by heat and helically winding a wire 38 into the outer surface of the tube thereby forming a wire coil 33 embedded in the tube 18 and the working channel tube.

[0078] FIG. 5 and FIG. 6 show the wire coil reinforced working channel tube 18 in a wire breaking machine during production. Before fixating the tube 18 a rigid metal rod 80 has been inserted into the tube 18. The working channel tube 18 has then been fixated such that translational as well as rotational movement is prevented by press fitting it into 7 U-shaped press fit retainers 81 at 7 different fixation locations 81 along the working channel tube 18. The metal rod 80 extends inside the working channel tube 18 at each location 81 it is fixated and at each exit point 29. There is a fixation location 81 within 5 working channel tube outer diameters D proximally and distally of each respective exit point 29. The two non-embedded wire portions 30, one at each end of the wire coil 33, have respectively been extended from their respective exit point 29 to a respective rotation location 40 located in the unembedded space and comprising a hook 51 around which they have been bent to form a bend 41 and respective first and second non-embedded wire sub portions 31, 32. Instead of a hook 51, any other suitable geometry could be used, for example the rotation location could comprise a ring (not shown) through which the non-embedded wire portions 30 could be threaded and bent around forming a bend 41 similar to how the non-embedded wire is bent around the hooks 51 in FIG. 5 and FIG. 6. Alternatively instead of a hook or ring the rotation location could comprise a clamp 52 such as shown in FIG. 7 to FIG. 10 where the non-embedded wire portion 30 is bent inside the clamp 52, which then clamps the first and second non-embedded wire sub portions 31, 32 in place before being rotated through help of the attached electric motor 44.

[0079] After bending round the hooks 51, the second non-embedded wire sub portions 32 have been extended back across the tube 18 over the same portion of the tube 18 where the respective exit point 29 is located and through a space normal to the respective exit points 29 to respective clamping locations 42 in the embedded space. The second non-embedded wire sub portions 32 have been clamped at the respective clamping locations 42 in clamps 43 configured to allow slippage of the wires 32 such that when the first and second non-embedded wire sub portions 31, 32 are rotated, a length of the second non-embedded wire sub portion 32 can slide out of the clamp 43 due to the pull on the wire 32 generated from the rotation and twisting of the first and second non-embedded wire sub portions 31, 32. In other words, the second non-embedded wire sub portions 32 could be said to be clamped loosely. This can be achieved by a low clamping force and/or a low friction or a combination thereof. After clamping of the second non-embedded wire sub portions 32, the respective first and second non-embedded wire sub portions 31, 32 are then rotated at the rotation location by rotating the hooks 51 driven by the electric motors 44 whereby the wires 31, 32 twist around each other until the wire breaks. That is to say, the steps S3 to S8 are repeated for both non-embedded wire portions respectively. FIG. 8 schematically shows what the twisting of the first and second non-embedded wire sub portions 31, 32 around each other looks like after a few rotations. In the embodiments shown there is a distance R, C of 0.5 or more but equal to or less than 10 working channel tube outer diameters D between the exit plane 36 and the rotation location 40, and between the exit plane 36 and the clamping location 42 respectively, the distance being measured perpendicularly to the exit plane 36. This is best seen in FIG. 7, where the distance R between the exit plane 36 and the portion of the clamp 52 that is closest to the exit plane 36 is more than 0.5 but less than one working channel tube outer diameter D, and the distance C between the exit plane 36 and the portion of the clamp 43 that is closest to the exit plane is close to one working channel tube outer diameter D.

[0080] As can be seen in FIG. 5, the non-embedded wire portion, towards the proximal end of the working channel tube 18, of which only the second non-embedded portion 32 is visible, extends substantially tangentially to the outer surface of the working channel tube 18. As can also be seen this is not the case for the first non-embedded wire sub portion 31 towards the distal end of the working channel tube 18 in detail BB. FIG. 6 is an enlarged view of detail BB in FIG. 5 where some of the press fit retainers 81 have been hidden for the purpose of illustration clarity. Here it can be seen that the rotation location 40 is located at an angle Ar to the exit point tangent line 34, and similarly that the clamping location 42 is located at a clamping angle Ac to the exit point tangent line 34. Both the rotation angle Ar and the clamping angle Ac are less than 25 degrees. Furthermore, the bend 41, the exit point 29 and the clamping location 42 can be seen.

[0081] In FIG. 7 and FIG. 8, the rotation location 40 and the clamping location 42 are located substantially on the exit point tangent line 34. This, however, need not be case as will be explained with reference to FIG. 9 and FIG. 10. As illustrated in FIG. 9, the rotation location 40 may be located such that a rotation angle Ar in a direction normal to the tube outer surface 28 at the exit point 29 between the exit point tangent line 34 and a straight line 53 extending from the exit point 29 to the rotation location 40 is 45 degrees or less, in this case about 30 degrees or less. The rotation angle Ar in general is preferably 45 degrees or less. The same is true for the clamping angle Ac between the exit point tangent line 34 and the straight line 54 extending between the exit point 29 and the clamping location 42, which in FIG. 9 (where the non-embedded wire has been hidden illustration clarity purposes) is approximately 30 degrees or less but in the opposite direction from the exit point tangent line 34 compared to the rotation angle Ar. In other embodiments, the rotation angle Ar may however also extend in the direction of the clamping angle Ac in FIG. 9, in fact both the rotation angle Ar and the clamping angle Ac may extend in any direction from the exit point tangent line 34 such as in a lateral direction away from a lateral plane 55 extending through the exit point 29 perpendicularly to the exit plane 36 as shown in FIG. 10. Preferably the rotation and clamping angles Ar, Ac are equal to or less than 45 degrees such as shown in the figures.

[0082] FIG. 11 shows a cross-section through the working channel tube 18 according to an embodiment of the present disclosure. The working channel tube 18 has a circular cross-section and comprises two layers, namely an outer layer 46 and an inner layer 48. Both the outer layer 46 and the inner layer 48 are essentially hollow elongated tube bodies and are preferably made of different materials. The outer layer 46 is provided directly around the inner layer 48 or, said differently, the inner layer 48 is inserted into the outer layer 46. A primer 50 may be provided between the outer layer 46 and the inner layer 48 in order to ensure adherence between the outer layer 46 and the inner layer 48. E.g. the outer layer 46 may be made of thermoplastic polyurethane (TPU) and the inner layer 48 may be made of high-density polyethylene (HDPE). The layers may be coextruded. T1 represents the wall thickness. T2 represents the inner layer thickness. T3 represents the outer layer thickness. The outer surface 28 is smooth with no protrusions or the like.

[0083] The embodiment shown in FIG. 11 is only an example and it is evident that it may be also advantageous if the working channel tube 18 is not made of two parts (the outer layer 46 and the inner layer 48) but is made of one integral elongated working channel tube part having the outer surface 28 and the inner surface 26 and being made of a meltable plastic material.

[0084] An embodiment according to which the working channel tube 18 is made of one integral part is shown in FIG. 12. FIG. 12 shows a longitudinal sectional view of a working channel tube 18 having a coil 33 embedded in a working channel tube 18. The wire 38 forming the coil 33 is covered by a material of the working channel tube 18 and is thus not exposed to (visible from) the outside.

[0085] According to another embodiment, the working channel tube 18 may have an outer diameter of 5.40.076 mm, an inner diameter of 4.40.076 mm and a tube wall thickness of 0.5 mm. The total length of the working channel tube 18 may be 1,500. The working channel tube 18 may comprise an outer layer 46, an inner layer 48 and a primer 50, which can also be designated as tie layer, between the outer layer 46 and the inner layer 48 as shown in FIG. 11. The material of the outer layer 46 may be a thermoplastic polyurethane like Pellethane 2363-90AE with additives according to the especially preferred embodiment. E.g., the outer layer 46 may comprise 70% Pellethane 2363-90AE and 30% additives. Among additives, it may be preferred if the outer layer 46 comprises an antimicrobial additive like BaSo4 and a friction reducing additive like ProPell. The material of the inner layer 48 may be a high-density polyethylene like Borealis Bormed HE9621-PH. The material of the primer 50 or tie layer may be a linear low-density polyethylene-based tie resin like Orevac 18300M.

[0086] In this present embodiment, the wire coil wire has an outer diameter of 0.15 mm and is made from stainless steel SUS304 comprising a BrNiCo coating.

[0087] The pitch of the coil 33 formed through the winding of the wire coil wire is 1 mm and the length of the section of the working channel tube 18, which is reinforced by the coil 33, is 1155 mm. The section reinforced by the coil 32 has an inner diameter, which is greater than 4.2 mm, and an outer diameter, which is smaller than 5.4 mm.

[0088] The disclosure has been described with reference to exemplary embodiments. However, the scope of the invention is not limited to the illustrated embodiments, and alterations and modifications can be carried out without deviating from the scope of the invention.

[0089] Throughout the description, the use of the terms first, second, etc. does not imply any particular order or importance but are included to identify individual elements. Furthermore, the labelling of a first element does not imply the presence of a second element and vice versa.

[0090] The following items are further variations and examples of the embodiments described with reference to the figures. [0091] 1. A method for producing a wire coil reinforced working channel tube for an endoscope, the method comprising: A) providing a working channel tube reinforced with a wire coil that is embedded between an inner and outer surface of the working channel tube, wherein a non-embedded wire portion of the wire coil extends out of the outer surface of the tube from an exit point, wherein an exit point tangent line that is tangent to the outer surface at the exit point defines two opposite directions extending away from the exit point: an unembedded direction extending away from a final embedded wire portion leading up to the exit point, and an embedded direction that is opposite the unembedded direction, wherein an exit plane extends through the exit point and a longitudinal axis of the tube, the space extending in the unembedded and embedded directions from the exit plane being defined as the unembedded space and embedded space, respectively; B) fixating the working channel tube; C) extending the non-embedded wire portion from the exit point to a rotation location located in the unembedded space; D) bending the non-embedded wire portion at the rotation location forming a bend and a first non-embedded wire sub portion extending from the exit point to the bend and a second non-embedded wire sub portion extending after the bend; E) extending the second non-embedded wire sub portion back across the tube to a clamping location located in the embedded space; F) clamping the second non-embedded wire sub portion at the clamping location in a clamp; and G) rotating the non-embedded wire sub portions at the rotation location such that the first and second non-embedded wire sub portions twist around each other until the wire breaks. [0092] 2. Method according to item 1, wherein the clamp in which the second non-embedded wire sub portion is clamped in is configured to allow slippage of the wire such that a length of the wire slides out of the clamp when pulled. [0093] 3. Method according to any one of the preceding items, wherein the rotation location is located in the unembedded space such that a rotation angle in a direction normal to the exit point and the tube outer surface between a straight line extending from the exit point to the rotation location and the exit point tangent line is 45 degrees or less. [0094] 4. Method according to any one of the preceding items, wherein the clamping location is located in the embedded space such that a clamping angle between the exit point tangent line and a straight line extending from the exit point to the clamping location is 45 degrees or less. [0095] 5. Method according to any one of the preceding items, wherein the rotation angle and the clamping angle is equal to or less than 10 degrees. [0096] 6. Method according to any one of the preceding items, wherein there is a distance of 0.5 or more, but equal to or less than 10 working channel tube outer diameters between the exit plane and the rotation location and between the exit plane and the clamping location respectively, the distance being measured perpendicularly to the exit plane. [0097] 7. Method according to any one of the preceding items, wherein a second non-embedded wire portion of the wire coil extends out of the outer surface of the tube from a different second exit point defining respective unembedded and embedded directions, wherein steps C) to G) are performed for the second non-embedded wire portion respectively. [0098] 8. Method according to any one of the preceding items, wherein the working channel tube is fixated such that there is a fixation location within 10 working channel tube outer diameters or less proximally of each respective exit point and a fixation location within 10 working channel tube outer diameters or less distally of each respective exit point. [0099] 9. Method according to any one of the preceding items, wherein a rod is inserted into the working channel tube before fixating the working channel tube in place. [0100] 10. Method according to item 9, wherein the rod is at least inserted a length such that it extends inside the working channel tube at each location the working channel tube is fixated and/or at each exit point. [0101] 11. Method according to any one of the preceding items wherein the embedded wire coil extends equal to or less than three quarters of a length of the working channel tube. [0102] 12. Method according to any one of the preceding items, wherein at least an outer layer of the working channel tube is made from a plastic material. [0103] 13. A reinforced working channel tube produced according to the method of any one of items 1-12. [0104] 14. An endoscope comprising a reinforced working channel tube according to item 13. [0105] 15. A visualization system comprising a video processing apparatus and an endoscope according to or 14, wherein the video processing apparatus (VPA) is couplable to the endoscope and capable of processing an image recorded by the endoscope and outputting the image on a display.

LIST OF REFERENCE SIGNS

[0106] 2 endoscope [0107] 4 endoscope handle [0108] 6 insertion cord [0109] 8 insertion tube [0110] 10 bending section [0111] 12 distal tip unit [0112] 14 working channel [0113] 16 working channel access port [0114] 18 working channel tube [0115] 20 first operating unit [0116] 22 second operating unit [0117] 25 working channel tube wall [0118] 26 inner surface [0119] 28 outer surface [0120] 29 exit point [0121] 30 non-embedded wire portion [0122] 31 first non-embedded wire sub portion [0123] 32 second non-embedded wire sub portion [0124] 33 wire coil [0125] 34 exit point tangent line [0126] 35 final embedded wire portion [0127] 36 exit plane [0128] 38 wire coil wire [0129] 40 rotation location [0130] 41 bend [0131] 42 clamping location [0132] 43 clamp [0133] 44 rotator [0134] 46 outer layer [0135] 48 inner layer [0136] 50 primer [0137] 51 hook [0138] 52 clamp [0139] 53 Straight line between exit point and rotation location [0140] 54 Straight line between exit point and clamping location [0141] 55 Lateral plane [0142] 60 segment [0143] 62 hinge [0144] 64 steering cable [0145] 66 steering cable guide [0146] 68 wires [0147] 70 spacing [0148] 72 cut-out lobe [0149] 80 rod [0150] 81 press fit retainer [0151] 100 visualization system [0152] 102 video processing apparatus [0153] 104 display screen [0154] 106 cable connector [0155] T1 wall thickness [0156] T2 inner layer thickness [0157] T3 outer layer thickness [0158] L longitudinal axis [0159] Ar rotation angle [0160] Ac clamping angle [0161] UD unembedded direction [0162] ED embedded direction [0163] D working channel tube outer diameter [0164] R distance between exit plane and rotation location [0165] C distance between exit plane and clamping location