REINFORCED WORKING CHANNEL TUBE FOR AN ENDOSCOPE

Abstract

A method for producing a reinforced working channel tube, a working channel tube produced by the method, a use of the working channel tube and an endoscope including the working channel tube, the method including: providing an elongated hollow tube main body, the tube main body having a meltable plastic material at least on its outer surface; at least locally heating a wire; tensioning the wire and winding the wire at least in sections around the outer surface of the tube main body; softening or melting the outer surface of the tube main body by the wire; securely anchoring or embedding the wire in the outer surface of the tube main body; and forming a coil anchored or embedded in the outer surface of the tube main body through the winding of the wire.

Claims

1. A method for producing a reinforced working channel tube for an endoscope, the method comprising: providing a tube main body having a longitudinal axis, the tube main body being an elongate hollow tube having an outer surface comprising a meltable plastic material; providing a wire; heating a portion of the wire; winding the heated portion of the wire under tension around the outer surface of at least a portion of the tube main body to form a coil having a coil pitch, the heated portion of the wire softening or melting the outer surface and penetrating through the softened or melted outer surface of the tube main body; and allowing the softened or melted outer surface of the tube main body to cool, wherein after cooling the coil is affixed to the tube main body.

2. The method of claim 1, wherein the tube main body comprises an inner layer and an outer layer, and wherein the inner layer and the outer layer comprise different materials.

3. The method of claim 2, wherein the inner layer has a higher Vicat Softening Point than the outer layer.

4. The method of claim 3, wherein the tube main body further comprises a tie layer between the inner layer and the outer layer.

5. The method of claim 1, wherein the coil is at least partially embedded in the outer layer.

6. The method of claim 1, wherein winding the heated portion of the wire comprises: turning the tube main body around its longitudinal axis at a rotational speed; and axially translating the wire along the longitudinal axis of the tube main body at a translational speed, wherein the translational speed and the rotational speed set the coil pitch.

7. The method of claim 6, wherein coil pitch is between 0.5 mm and 1.5 mm.

8. The method of claim 7, wherein coil pitch is between 0.8 mm and 1.2 mm.

9. The method of claim 1, wherein heating the portion of the wire comprises passing the wire over a heating element.

10. The method of claim 8, wherein winding the heated portion of the wire under tension around the outer surface of the at least the portion of the tube main body comprises positioning the heated portion of the wire onto the outer surface before a temperature of the heated portion of the wire is lower than a softening point of the meltable plastic material.

11. The method of claim 1, wherein winding the heated portion of the wire under tension comprises tensioning the wire to between 0.5 N and 3.0 N during the winding.

12. The method of claim 11, wherein winding the heated portion of the wire under tension comprises tensioning the wire to between 1.6 N and 2.4 N during the winding.

13. The method of claim 1, wherein the tube main body comprises an inner diameter of between 2.0 mm and 4.5 mm.

14. The method of claim 13, wherein the tube main body comprises a wall having a wall thickness of less than 0.5 mm.

15. The method of claim 14, wherein the wall thickness is at least two times greater than a diameter or thickness of the wire.

16. A working channel tube comprising: a tube main body having a longitudinal axis, the tube main body being an elongate hollow tube having an outer surface comprising a meltable plastic material; and a wire wound around the outer surface of at least a portion of the tube main body to form a coil having a coil pitch, wherein the wire is affixed to the tube main body by the method of claim 1 to form the coil.

17. The working channel tube of claim 16, wherein the tube main body has an inner diameter of between 2 mm and 4.5 mm.

18. The working channel tube of claim 16, wherein the coil pitch is between 0.5 mm and 1.5 mm.

19. The working channel tube of claim 16, wherein the tube main body comprises an outer layer having an outer surface and an inner layer having an inner surface, wherein a material of the outer layer is different from a material of the inner layer.

20. The working channel tube of claim 19, wherein the material of the inner layer has a Vicat Softening Point higher than a Vicat Softening Point of the material of the outer layer.

21. The working channel tube of claim 20, wherein a wall thickness of a wall of the tube main body is at least two times greater than a diameter or thickness of the wire.

22. An endoscope comprising: an endoscope handle or interface comprising a handle or interface housing and a working channel access port; an insertion cord configured to be inserted into a patient's body cavity and comprising an insertion tube, a bending section and a distal tip unit; and a working channel extending from the working channel access port of the endoscope handle or interface to the distal tip unit of the insertion cord and comprising the working channel tube of claim 16.

Description

BRIEF DESCRIPTION OF FIGURES

[0057] The disclosure is explained in more detail below using preferred embodiments and referring to the accompanying figures.

[0058] FIG. 1 shows a schematic view of an embodiment of an endoscope according to the present disclosure.

[0059] FIG. 2 shows a flow chart of a method for producing a working channel tube according to the present disclosure.

[0060] FIG. 3 shows the working channel tube according to the present disclosure during its production.

[0061] FIG. 4 shows an arrangement of a tube main body in a winding apparatus.

[0062] FIG. 5 shows a cross-section through a tube main body according to an embodiment of the present disclosure.

[0063] FIG. 6 is a longitudinal sectional view of a working channel tube having a coil embedded in a tube main body according to an embodiment of the present disclosure.

[0064] FIG. 7 is a longitudinal sectional view of a working channel tube having a coil anchored in a tube main body according to an embodiment of the present disclosure.

[0065] FIG. 8 is a side view of a bending section showing a working channel tube.

[0066] FIG. 9 is cross-section A-A of the bending section of FIG. 8.

[0067] FIG. 10 is a side view of a visualization system including another embodiment of an endoscope according to the present disclosure.

[0068] 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

[0069] FIG. 1 shows a schematic view of an endoscope 2, which is preferably a single-use endoscope. 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/turning 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/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, an example of which is shown in FIG. 10.

[0070] FIG. 8 shows an embodiment of a bending section 10 showing a working channel tube 18 (the reinforcement is not shown). FIG. 9 is cross-section A-A of the bending section of FIG. 8 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. 9, 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 video processing apparatus (VPA) 102 shown in FIG. 10. As can be envisioned, 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.

[0071] FIG. 10 is a side view of a visualization system 100 including another embodiment of an endoscope 2 showing the cable connector 106, which can be connected to an endoscope connection port (not shown) of the 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.

[0072] The working channel tube 18 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 to be understood that it is also conceivable 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, it is to be understood that the working channel tube 18 does not need to be arranged inside the insertion cord 6 but may alternatively also be attached to the insertion cord 6 from outside.

[0073] With reference to FIG. 2, FIG. 3 and FIG. 4 a method for producing a reinforced working channel tube 18 according to the present disclosure is described. FIG. 2 shows a flow chart of the method for producing a reinforced working channel tube 18. In a first step S1, an elongated hollow tube main body 24 comprising an inner surface 26 and an outer surface 28 is provided. The tube main body 24 comprises, at least on its outer surface 28, a meltable plastic material. The inner surface 26 and the outer surface 28 may, initially, when provided, be essentially smooth, e.g. devoid of grooves, channels, and/or corrugations.

[0074] In a step S2 a wire 30, preferably made of metal, is provided. The wire 30 is at least locally heated in a step S3.

[0075] In a step S4 a tensioning is applied on the wire 30 and the at least locally heated wire 30 is at least in sections directly wound around the outer surface 28 of the tube main body 24. The heated wire 30 softens or melts the outer surface 28 of the tube main body 24 in a step S5. In a further step S6 the wire is securely anchored or embedded in the outer surface 28 of the tube main body 24. In a step S7 a coil 32 anchored or embedded in the outer surface 28 of the tube main body 24 is formed through the winding of the wire 30. It is to be understood that the process steps S4 to S7 are performed simultaneously/follow immediately one after another. In particular, when the at least locally heated wire 30 is wound around the outer surface 28 of the tube main body 24, it is a direct consequence of the temperature of the wire 30 and the tension applied on the wire 30 that the wire 30 softens/melts the outer surface 28 of the tube main body 24. Moreover, a direct consequence of the softening/melting of the outer surface 28 of the tube main body is the secure anchoring/embedding of the wire 30 in the outer surface 28 of the tube main body 24. The formation of the coil 32 is the direct consequence of the winding and anchoring/embedding.

[0076] The method preferably comprises fixing a first end of the wire to the tube main body before forming the coil. Fixing the end of the wire to the tube main body facilitates tensioning and coiling of the wire around the tube main body. The wire may be broken, from a spool or portion of wire that is not attached, flush with the outer surface of the tube main body. This provides the advantage that a risk of a sharp wire end sticking out of the outer surface of the tube main body is reduced. Fixing the end of the wire may comprise heating the end of the wire and applying pressure onto the end of the wire to locally melt the tube main body and thus, upon cooling, securing the end of the wire to the tube main body. The end of the wire may be bent at a sharp angle to form small hook and thus prevent the tip of the end of the wire to potentially damage other parts of the endoscope.

[0077] The method preferably comprises fixing a second end of the wire, opposite the first end, to the tube main body after forming the coil. Fixing the end of the wire may comprise heating the end of the wire and applying pressure onto the end of the wire to locally melt the tube main body and thus, upon cooling, securing the end of the wire to the tube main body. The end of the wire may be bent at a sharp angle to form small hook and thus prevent the tip of the end of the wire to potentially damage other parts of the endoscope. The wire may be broken flush with the outer surface of the tube main body. This provides the advantage that a risk of a sharp wire end sticking out of the outer surface of the tube main body is reduced.

[0078] Preferably, the wire is broken off after completion of the winding, e.g. by bending the wire multiple times in different directions. It may be especially preferred if a sharp bend, in particular a kink, is provided to the wire at the outer surface of the tube main body before bending the wire back and forth multiple times in different directions. E.g. the end of the wire may be pushed against the tube main body, in particular against the outer surface of the tube main body, at a specific position, and the sharp bend of the wire may be provided at said specific position. The sharp bend is preferably performed such that a weakness point or starting point for breaking off the wire is provided on the outer surface of the tube main body or at least very close to the outer surface of the tube main body so that the wire is preferably broken flush with the outer surface of the tube main body when the wire is subsequently bent back and forth multiple times in different directions. The sharp bend can e.g. be manually provided by pushing the wire against the specific position by a fingernail, or automatically by a pushing or pressing body. Breaking the wire flush with the outer surface of the tube main body provides the advantage that a risk of a sharp wire end sticking out of the outer surface of the tube main body is reduced, thereby reducing a potential risk of damaging other components of the endoscope, such as a camera wire, other tubes, etc., in particular in the assembly process. Alternatively, the wire may be cut after termination of the winding process.

[0079] The risk of the wire end sticking out of the outer surface of the tube main body may be further reduced, in particular after breaking off the wire by the sharp bend as mentioned above, by adding a drop of adhesive to the wire end, thereby covering the wire end with adhesive, and fixing the wire end to the tube main body. The end of the wire may be additionally or alternatively anchored or embedded in the tube main body after the winding is completed, e.g. by locally heating and melting the tube main body and pressing the end of the wire into the locally heated and melted portion of the tube main body. Thus, the end of the wire may be fixed to the tube main body. Said differently, the method preferably also comprises the step: fixing a free end of the wire to the tube main body by locally heating and melting a portion of the tube main body and pressing the free end of the wire into said portion of the tube main body. Additionally or alternatively, fixing a free end of the wire to the tube main body may comprise locally heating the free end of the wire and then pressing the free end to melt a portion of the tube main body into said portion of the tube main body.

[0080] FIG. 3 shows the working channel tube 18 for the endoscope 2 during production. The working channel tube 18 comprises the tube main body 24 and the wire 30. The wire 30 is wound around the tube main body 24 and during the winding process, the wire 30 is locally heated to a specific temperature and is tensioned, e.g. by a tensioning force of around 2 N, so that the outer surface 28 of the tube main body 24 melts and the wire 30 cuts into and is embedded/anchored in the outer surface 28 of the tube main body 24. The wire 30 is preferably a metal wire, e.g. a steel thread, in particular stainless steel. Moreover, the wire preferably has a round cross-section and a wire diameter of between 0.15 and 0.07 mm, between 0.12 and 0.08 mm, e.g. 0.10 mm. The wire diameter may be selected based on the wall thickness and the composition of the tube main body 24. The wound wire 30 forms a reinforcing coil 32 at least in sections around the tube main body 24. The winding of the wire 30 is performed such that a specific desired pitch may be reached, which serves to adjust a reinforcement-degree. E.g. the pitch can be set such that it is between 0.5 mm and 1.5 mm, e.g. around 1 mm. The reinforcement-degree may additionally or alternatively be adjusted by appropriately setting a cross-sectional area of the wire 30. The tube main body 24 may have an inner diameter (defined by the inner surface 26) of around 3.8 mm or less, 3.2 mm or less, or 2.8 mm or less. A wall thickness of the tube main body 24 may equal to or less than 0.5 mm, or 0.4 mm or less.

[0081] FIG. 4 shows an arrangement of the tube main body 24 in a winding apparatus 34. The winding apparatus 34 comprises a control unit 36, a spindle 38, a slide 40, a winch 42 and a heating element 44. The heating element 44 comprises a metal portion and an electrical resistive element capable of generating heat upon the conduction therethrough of electrical current, e.g. a soldering iron. The tube main body 24 is mounted to the spindle 38 and may be rotated by the spindle 38. The winch 42 and the heating element 44 are fixedly connected to the slide 40, which may be displaced/moved in an axial direction of the tube main body 24. The slide may comprise a slot 41 over which the tube main body 24 rotates. The slot 41 depth can be used to ensure the wire 30 approaches the outer surface 28 of the tube main body 24 at a relative position to ensure the wire 30 does not penetrate too deeply into the wall 25 of the tube main body 24. The slot 41 may also provide a measure of cooling after the heated wire is wound. A guide surface 43 on the slide can be used instead to set the approach angle and position of the wire. The control unit 36 controls parameters of the production process, e.g. the axial translation velocity of the slide 40 or the rotational speed of the spindle 38 or a tensioning force applied on the wire 30. The winch 42 may provide the wire 30. The wire 30 is locally heated by passing the wire 30 over the metal surface of the heating element 44 and is then directly wound around the tube main body 24. The winding is performed by rotating the tube main body 24 around its longitudinal axis by the spindle 38 and by axially moving the slide 40 and the winch 42 (and thus the wire 30) along the longitudinal axis of the tube main body 24 according to this preferred embodiment. A pair of opposing wheels, with the wire 30 passing therebetween, may apply a braking force to set the tension on the wire 30 in combination with the rotating speed of the spindle.

[0082] FIG. 5 shows a cross-section through the tube main body 24 according to an embodiment of the present disclosure. The tube main body 24 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.

[0083] The materials used for the outer layer 46 and the inner layer 48 may also be chosen such that they are both meltable plastic materials and a melting temperature of the material of the inner layer 48 is higher than a melting temperature of the material of the outer layer 46. In this case, the temperature of the wire 30 can be adjusted such that it is between the melting temperature of the material of the outer layer 46 and the melting temperature of the material of the inner layer 48. The melting temperature of a polymer is a temperature at which a crystalline polymer converts to a liquid, or crystalline domains of a semi-crystalline polymer melt. Pellethane® 2363-90AE, for example, has an extrusion melt temperature of 370-400° F., and a Vicat Softening Point of 165° F. (ASTM D1525 2° C./min, 9,8N). By using a material in the inner layer that softens at a higher temperature than the material of the outer layer it is possible to increase the wire temperature range without damaging the integrity of the tube main body, regardless which temperature measurement technique is used.

[0084] The embodiment shown in FIG. 5 is only an example and it is evident that it may be also advantageous if the tube main body 24 is not made of two parts (the outer layer 46 and the inner layer 48) but is made of one integral elongated tube main body part having the outer surface 28 and the inner surface 26 and being made of a meltable plastic material.

[0085] Embodiments according to which the tube main body 24 is made of one integral part are shown in FIG. 6 or in FIG. 7. FIG. 6 shows a longitudinal sectional view of a working channel tube 18 having a coil 32 embedded in a tube main body 24. The wire 30 forming the coil 32 is covered by a material of the tube main body 24 and is thus not exposed to (visible from) the outside, since the melted plastic material has flown over the wire 30/has closed a gap or groove created through the winding of the wire 30 around the tube main body 24 during the production process. FIG. 7 shows a longitudinal sectional view of a working channel tube 18 having a coil 32 anchored in a tube main body 24. The wire 30 forming the coil 32 is not entirely covered by the material of the tube main body 24 after the production of the working channel tube 18 and is thus still visible from outside. Preferably, more than 50% of the diameter, measured perpendicular to the outer surface, is embedded in the material, such that upon cooling the material mechanically affixes the wire.

[0086] According to an especially preferred embodiment, the tube main body 24 may have an outer diameter of 5.4±0.076 mm, an inner diameter of 4.4±0.076 mm and a tube wall thickness of 0.5 mm. The total length of the tube main body 24 may be 1,500 mm according to the especially preferred embodiment. The tube main body 24 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 according to the especially preferred embodiment. 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.

[0087] The wire 30 may have an outer diameter of 0.15 mm according to the especially preferred embodiment. The material of the wire may be stainless steel according to the especially preferred embodiment, e.g. SUS304. The wire made of SUS304 may comprise a Br—Ni—Co coating.

[0088] The pitch of the coil 32 formed through the winding of the wire 30 may be 1 mm according to the especially preferred embodiment. The length of the section of the tube main body 24, which is reinforced by the coil 32, may be 115±5 mm according to the especially preferred embodiment. The section reinforced by the coil 32 may have an inner diameter, which is greater than 4.2 mm, and an outer diameter, which is smaller than 5.4 mm.

[0089] The kinking performance of the tube main body 24 according to the especially preferred embodiment with and without reinforcement by the coil 32 has been tested. In particular, bending diameters of 23 mm, 30 mm, 40 mm, 50 mm and 60 mm have been tested. It has shown that the tube main body 24 without reinforcement by the coil 32 does kink for bending diameters of 23 mm, 30 mm and 40 mm and does not kink for bending diameters of 50 mm and 60 mm. The tube main body 24 with reinforcement by the coil 32 does only kink for a bending diameter of 23 mm and does not kink for bending diameters of 30 mm, 40 mm, 50 mm and 60 mm. Therefore, it has shown that according to the present disclosure kinking performance of the working channel tube 18 may be improved.

[0090] The following items are examples of various embodiments and variations thereof disclosed above and others:

[0091] Item 1. A method for producing a reinforced working channel tube (18) for an endoscope (2), the method comprising: providing an elongated hollow tube main body (24) initially having an essentially smooth inner surface (26) and an essentially smooth outer surface (28) and comprising a meltable plastic material at least on its outer surface (28); providing a wire (30), preferably made of metal; at least locally heating the wire (30); applying a tensioning on the wire (30) and winding the at least locally heated wire (30) at least in sections around the outer surface (28) of the tube main body (24); softening or melting the outer surface (28) of the tube main body (24) by the wire (30); securely anchoring or embedding the wire (30) in the outer surface (28) of the tube main body (24); and forming a coil (32) anchored or embedded in the outer surface (28) of the tube main body (24) through the winding of the wire (30).

[0092] Item 2. The method according to item 1, further comprising: turning the tube main body (24) around its longitudinal axis; axially moving the tensioned wire (30) along the longitudinal axis of the tube main body (24); and creating a specific or desired pitch of the coil (32), preferably between 0.5 mm and 1.5 mm, especially preferred around 1 mm, by correspondingly setting a rotational speed of the tube main body (24) and an axial movement velocity of the wire (30).

[0093] Item 3. The method according to item 1 or 2, further comprising: heating the wire (30) only locally immediately before winding the locally heated wire (30) around the smooth outer surface (28) of the tube main body (24).

[0094] Item 4. The method according to any one of items 1 to 3, further comprising: tensioning the wire (30) between 0.1 N and 10 N, preferably between 0.5 N and 3 N, especially preferred around 2 N, during the winding.

[0095] Item 5. The method according to any one of items 1 to 4, further comprising: winding the wire (30) only in sections around the outer surface (28) of the tube main body (24), i.e. not along an entire length of the tube main body (24), thus providing an only locally reinforced working channel tube (18).

[0096] Item 6. The method according to any one of items 1 to 5, further comprising: providing the elongated hollow tube main body (24) with an outer layer (46) comprising the outer surface (28) and an inner layer (48) comprising the inner surface (26), wherein a material of the outer layer (46) is different from a material of the inner layer (48).

[0097] Item 7. A working channel tube (18) comprising: an elongated hollow tube main body (24) having an essentially smooth inner surface (26) and comprising a meltable plastic material at least on its outer surface (28); and a coil (32), preferably made of metal, firmly attached and anchored or embedded in the outer surface (28) of the tube main body (24), the coil (32) being formed by: providing a wire (30); at least locally heating the wire (30); applying a tensioning on the wire (30) and winding the at least locally heated wire (30) at least in sections around an initially smooth outer surface (28) of the tube main body (24); softening or melting the outer surface (28) of the tube main body (24) by the wire (30); and securely anchoring or embedding the wire (30) in the outer surface (28) of the tube main body (24).

[0098] Item 8. The working channel tube (18) according to item 7, wherein the tube main body (24) has an inner diameter between 2 mm and 4.5 mm.

[0099] Item 9. The working channel tube (18) according to item 7 or 8, wherein a pitch of the coil (32) is between 0.5 mm and 1.5 mm, especially preferred around 1 mm.

[0100] Item 10. The working channel tube (18) according to any one of the items 7 to 9, wherein the elongated hollow tube main body (24) comprises an outer layer (46) comprising the outer surface (28) and an inner layer (48) comprising the inner surface (26), wherein a material of the outer layer (46) is different from a material of the inner layer (48).

[0101] Item 11. The working channel tube (18) according to item 10, wherein the materials of the outer layer (46) and the inner layer (48) are both meltable plastic materials and a melting temperature of the material of the inner layer (48) is higher than a melting temperature of the material of the outer layer (46).

[0102] Item 12. The working channel tube (18) according to any one of the items 7 to 11, wherein a wall thickness of the elongated hollow tube main body (24) is at least two times greater than a diameter or thickness of the wire (30).

[0103] Item 13. Use of a working channel tube (18) according to any one of items 7 to 12 as part of an internal or external working channel (14) of an endoscope (2).

[0104] Item 14. An endoscope (2) comprising: an endoscope handle (4) or interface comprising a handle or interface housing and a working channel access port (16); an insertion cord (6) configured to be inserted into a patient's body cavity and comprising an insertion tube (8), an actively bendable bending section (10) and a distal tip unit (12); a working channel (14) extending from the working channel access port (16) of the endoscope handle (4) or interface to the distal tip unit (12) of the insertion cord (6) and comprising the working channel tube (18) according to any one of items 7 to 12.

[0105] Item 15. The endoscope (2) according to item 14, wherein the working channel tube (18) extends through the bending section (10) and is locally reinforced by the coil (32) in the bending section (10).

[0106] Item 16. A method for producing a reinforced working channel tube for an endoscope, the method comprising: providing a tube main body having a longitudinal axis, the tube main body being an elongate hollow tube having an outer surface comprising a meltable plastic material; providing a wire; heating a portion of the wire; winding the heated portion of the wire under tension around the outer surface of at least a portion of the tube main body to form a coil having a coil pitch, the heated portion of the wire softening or melting the outer surface and penetrating through the softened or melted outer surface of the tube main body; and allowing the softened or melted outer surface of the tube main body to cool, wherein after cooling the coil is affixed to the tube main body.

[0107] Item 17. The method of item 16, wherein the tube main body comprises an inner layer and an outer layer, and wherein the inner layer and the outer layer comprise different materials.

[0108] Item 18. The method of items 16 or 17, wherein the inner layer has a higher Vicat Softening Point than the outer layer.

[0109] Item 19. The method of item 18, wherein the tube main body further comprises a tie layer between the inner layer and the outer layer.

[0110] Item 20. The method of any one of items 16 to 19, wherein the coil is at least partially embedded in the outer layer.

[0111] Item 21. The method of any one of items 16 to 20, wherein winding the heated portion of the wire comprises: turning the tube main body around its longitudinal axis at a rotational speed; and axially translating the wire along the longitudinal axis of the tube main body at a translational speed, wherein the translational speed and the rotational speed set the coil pitch.

[0112] Item 22. The method of any one of items 16 to 21, wherein coil pitch is between 0.5 mm and 1.5 mm.

[0113] Item 23. The method of item 22, wherein coil pitch is between 0.8 mm and 1.2 mm.

[0114] Item 24. The method of any one of items 16 to 23, wherein heating the portion of the wire comprises passing the wire over a heating element.

[0115] Item 25. The method of any one of items 16 to 24, wherein winding the heated portion of the wire under tension around the outer surface of the at least the portion of the tube main body comprises positioning the heated portion of the wire onto the outer surface before a temperature of the heated portion of the wire is lower than a softening point of the meltable plastic material.

[0116] Item 26. The method of any one of items 16 to 25, wherein winding the heated portion of the wire under tension comprises tensioning the wire to between 0.5 N and 3.0 N during the winding.

[0117] Item 27. The method of item 26, wherein winding the heated portion of the wire under tension comprises tensioning the wire to between 1.6 N and 2.4 N during the winding.

[0118] Item 28. The method of any one of items 16 to 27, wherein the tube main body comprises an inner diameter of between 2.0 mm and 4.5 mm.

[0119] Item 29. The method of any one of items 16 to 28, wherein the tube main body comprises a wall having a wall thickness of less than 0.5 mm.

[0120] Item 30. The method of any one of items 16 to 29, wherein the wall thickness is at least two times greater than a diameter or thickness of the wire.

[0121] Item 31. A working channel tube comprising: a tube main body having a longitudinal axis, the tube main body being an elongate hollow tube having an outer surface comprising a meltable plastic material; and a wire wound around the outer surface of at least a portion of the tube main body to form a coil having a coil pitch, wherein the wire is affixed to the tube main body by the method of any one of items 16 to 30 to form the coil.

[0122] Item 32. The working channel tube of item 31, wherein the tube main body has an inner diameter of between 2 mm and 4.5 mm.

[0123] Item 33. The working channel tube of any one of items 31 to 32, wherein the coil pitch is between 0.5 mm and 1.5 mm.

[0124] Item 34. The working channel tube of any one of items 31 to 33, wherein the tube main body comprises an outer layer having an outer surface and an inner layer having an inner surface, wherein a material of the outer layer is different from a material of the inner layer.

[0125] Item 35. The working channel tube of any one of items 31 to 34, wherein the material of the inner layer has a Vicat Softening Point higher than a Vicat Softening Point of the material of the outer layer.

[0126] Item 36. The working channel tube of any one of items 31 to 35, wherein a wall thickness of a wall of the tube main body is at least two times greater than a diameter or thickness of the wire.

[0127] Item 37. An endoscope comprising: an endoscope handle or interface comprising a handle or interface housing and a working channel access port; an insertion cord configured to be inserted into a patient's body cavity and comprising an insertion tube, a bending section and a distal tip unit; and a working channel extending from the working channel access port of the endoscope handle or interface to the distal tip unit of the insertion cord and comprising the working channel tube of any one of items 31 to 36.

LIST OF REFERENCE SIGNS

[0128] 2 endoscope

[0129] 4 endoscope handle

[0130] 6 insertion cord

[0131] 8 insertion tube

[0132] 10 bending section

[0133] 12 distal tip unit

[0134] 14 working channel

[0135] 16 working channel access port

[0136] 18 working channel tube

[0137] 20 first operating unit

[0138] 22 second operating unit

[0139] 24 tube main body

[0140] 25 tube main body wall

[0141] 26 inner surface

[0142] 28 outer surface

[0143] 30 wire

[0144] 32 coil

[0145] 34 winding apparatus

[0146] 36 control unit

[0147] 38 spindle

[0148] 40 slide

[0149] 41 slide slot

[0150] 42 winch

[0151] 43 slide channel guide surface

[0152] 44 heating element

[0153] 46 outer layer

[0154] 48 inner layer

[0155] 50 primer

[0156] 60 segment

[0157] 62 hinge

[0158] 64 steering cable

[0159] 66 steering cable guide

[0160] 68 wires

[0161] 70 spacing

[0162] 72 cut-out lobe

[0163] 100 visualization system

[0164] 102 video processing apparatus

[0165] 104 display screen

[0166] 106 cable connector

[0167] T1 wall thickness

[0168] T2 inner layer thickness

[0169] T3 outer layer thickness