Endoscope device for a flexible endoscope and method for its manufacture

Description

State of the art

[0001] The invention relates to an endoscope device according to the preamble of claim 1 and to a method for manufacturing an endoscope device according to the preamble of claim 18.

[0002] Endoscope devices are already known which have at least one working channel which has a tubular working channel jacket which limits a working channel volume in which, for example, at least one surgical instrument can be arranged, wherein the working channel jacket has at least one jacket layer which comprises at least one plastic material, and at least one further jacket layer which comprises at least one further plastic material which is designed differently from the plastic material of the jacket layer.Such endoscope devices are described, for example, in documents US 2003 / 220545 A1, US 2009 / 112066 A1, US 2010 / 075075 A1, DE 101 22 203 A1, US 2010 / 256455 A1, and US 2004 / 106853 A1. The object of the invention is, in particular, to provide a generic device with improved working channel properties, wherein the working channel is advantageously designed to be flexible. This object is achieved according to the invention by the features of claim 1, while advantageous embodiments and further developments of the invention can be found in the dependent claims. Advantages of the invention

[0003] The invention relates to an endoscope device for an endoscope, in particular a flexible endoscope, with at least one working channel which has a tubular working channel sheath which limits a working channel volume of the working channel, wherein the working channel sheath has at least one sheath layer which comprises at least one plastic material, and at least one further sheath layer which comprises at least one further plastic material which is different from the plastic material of one sheath layer.

[0004] It is proposed that the sheath layer along the main extent of the working channel has a constant thickness, and that the further sheath layer along the main extent of the working channel has a variable thickness in certain sections. Varying the layer thickness can improve the arrangement of the working channel, particularly within an endoscope shaft and / or at an endoscope tip. Furthermore, it can advantageously improve the stability of the working channel.

[0005] The term "endoscope device" shall be understood to mean, in particular, a preferably functional component of an endoscope, especially a subassembly and / or a structural and / or functional component of an endoscope. Alternatively, the endoscope device may constitute an endoscope at least partially, preferably at least to a large extent, and particularly preferably completely. The term "at least to a large extent" shall be understood to mean, in particular, at least 55%, preferably at least 65%, preferably at least 75%, particularly preferably at least 85%, and most preferably at least 95%, as well as advantageously completely, particularly with regard to the volume and / or mass of an object.The endoscope device is, for example, designed to be inserted, at least partially and preferably at least to a large extent, into an artificial or natural opening, in particular a body orifice, in order to perform a treatment or examination. "Designed" is understood to mean, in particular, specifically programmed, provided, designed, formed, and / or equipped. The fact that an object is designed for a specific function is understood to mean, in particular, that the object fulfills or performs this specific function in at least one application or operating state.

[0006] The endoscope device includes, in particular, an endoscope shaft within which the working channel is arranged. The endoscope shaft is designed to be inserted, at least partially and preferably at least to a large extent, into an opening, particularly an artificial or natural opening, especially a body orifice. "Distal" is understood to mean, in particular, when operating the device, facing the patient and away from the operator. "Proximal" is understood to mean, in particular, when operating the device, facing away from the patient and towards the operator. The working channel is designed as an elongated object and is suitable, for example, for accommodating a surgical instrument within it or for transporting liquids or gases within it.An "elongated component" shall be understood to mean, in particular, a component whose principal extent is greater by at least a factor of five, preferably by at least a factor of ten, and most preferably by at least a factor of twenty than an extent of the component at least substantially perpendicular to the principal extent, i.e., in particular, a diameter of the component. A "principal extent direction" of a component shall be understood to mean, in particular, a direction that runs parallel to a longest edge of the smallest imaginary cuboid that just completely encloses the component.The term "at least substantially parallel" here refers in particular to an alignment of a direction relative to a reference direction, especially in a plane, wherein the direction and the reference direction form an angle of 0°, particularly considering a maximum deviation of less than 8°, advantageously less than 5°, and most advantageously less than 2°. The term "at least substantially perpendicular" here refers in particular to an alignment of a direction relative to a reference direction, especially in a plane, wherein the direction and the reference direction form an angle of 90°, particularly considering a maximum deviation of less than 8°, advantageously less than 5°, and most advantageously less than 2°.The term "main extent" of an object is understood in particular to mean an extent of the object which runs along the longest edge of the smallest imaginary cuboid which just completely encloses the object.

[0007] The working channel jacket has, in particular, an inner diameter of at least 0.5 mm, preferably at least 1.5 mm, and particularly preferably at least 2 mm and / or at most 12 mm, preferably at most 5 mm, and particularly preferably at most 3 mm. The jacket layer has, in particular, a layer thickness of at least 1.5%, preferably at least 2%, and particularly preferably at least 3%, and / or at most 10%, preferably at most 7%, and particularly preferably at most 4% of the inner diameter.

[0008] Since the thickness of the additional jacket layer varies section by section along the main extent of the working channel, the additional jacket layer in a section has a thickness which corresponds in particular to at least 5%, preferably at least 6% and particularly preferably at least 10% and / or at most 15%, preferably at most 13% and particularly preferably at most 11% of the inner diameter.

[0009] The further jacket layer can have a layer thickness in the further section of the working channel jacket that is reduced by at least 10%, preferably at least 25%, particularly preferably at least 40% or more than 50% compared to the layer thickness in the first section.

[0010] Alternatively or additionally, the additional sheath layer in a further section of the working channel sheath can have a thickness of at least 0.1%, preferably at least 0.14%, and particularly preferably at least 0.18% and / or at most 0.28%, preferably at most 0.24%, and particularly preferably at most 0.2% of the inner diameter. The installation space in the distal end section of endoscopes, which accommodates various other components such as image sensors, illumination units, or parts of the endoscope shaft, may be so limited that a significant reduction in the thickness of the additional sheath layer in some sections of the working channel sheath is advantageous in order to create additional space.

[0011] The working channel is particularly flexible. The outer sheath layer and the additional sheath layer extend, in particular, at least substantially parallel along the main extent. The outer sheath layer and the additional sheath layer are particularly arranged coaxially. The additional sheath layer surrounds the outer sheath layer, particularly along a circumference of the working channel sheath, at least partially, preferably at least to a large extent, and most preferably completely. The outer sheath layer and the additional sheath layer form the working channel sheath at least partially, preferably at least to a large extent, and most preferably completely. One of the plastic materials forms, in particular, at least partially, preferably at least to a large extent, and most preferably completely, the sheath layer. In other words, one of the sheath layers can be free of another plastic material.Furthermore, the additional jacket layer is, in particular, at least partially, preferably at least to a large extent, and especially preferably entirely, made of the additional plastic material. In other words, the additional jacket layer can be free of any additional plastic. Since the one plastic material and the additional plastic material are different from each other, they together form at least a partial composite material from which the working channel jacket is at least partially formed. Preferably, the plastic material and the additional plastic material are bonded together by a material-bonded and / or form-fit connection.

[0012] By forming the sheath layers from the plastic materials as described above, it is possible in particular to create a working channel with a particularly small diameter and low wall thickness, which is suitable for endoscope devices and endoscopes with a very small diameter.

[0013] To further reduce the diameter, it is proposed that the thickness of the additional jacket layer decreases section by section along the main extent of the working channel. Preferably, the thickness of the additional jacket layer decreases section by section along the main extent of the working channel in a distal direction. In particular, a first section of the working channel jacket is a proximal section and a further section of the working channel jacket is a distal section. Furthermore, the working channel jacket can have an intermediate section located between the first section and the further section. Preferably, the greater thickness of the first section transitions continuously within the intermediate section into the, in particular, lesser thickness of the further section. The intermediate section can have a length of a few millimeters, preferably less than 5 mm.The mantle layer can have a thickness as described above in the first and subsequent sections.

[0014] It is further proposed that the working channel jacket be at least partially free of the additional jacket layer. A particularly compact design of the working channel jacket can advantageously be achieved. For example, the additional section could be free of the second jacket layer. In other words, the thickness of the additional jacket layer in this additional section could be zero.

[0015] The distal section can be, in particular, a distal end section of the working channel jacket. Preferably, this distal end section is free of the remaining jacket layer. This can advantageously further simplify assembly and reduce the diameter of the working channel, especially in the distal region.

[0016] The outer layer and the inner layer can be arranged adjacent to each other. Furthermore, it is proposed that the outer layer and the inner layer be in contact with each other. This advantageously creates a particularly stable working channel lining.

[0017] It is proposed that the sheath layer and the second sheath layer be bonded together by a material-bonded and / or form-fit connection. Advantageously, a composite material can be formed from the two plastic materials of the first and second sheath layers, for example, by applying pressure and heat. This prevents delamination, i.e., separation of the two layers from each other, when the working channel is bent. Working channels in flexible endoscopes are frequently subjected to bends with a small bending radius.

[0018] It is further proposed that the jacket layer forms an inner surface of the working channel jacket, and the additional jacket layer forms an outer surface of the working channel jacket. Advantageously, a homogeneous inner surface can be provided, which is hardly affected by any possible configuration of an additional jacket layer that stabilizes the jacket layer.

[0019] It is further proposed that the inner diameter of the working channel lining be constant, or at least substantially constant, along the main extent of the working channel. It can advantageously be ensured that a surgical instrument positioned within the working channel volume bounded by the working channel lining can be positioned and / or passed through the entire main extent of the working channel without being damaged or becoming stuck. The working channel may nevertheless have bends or branches.

[0020] It is further proposed that the outer diameter of the working channel sheath be variable along the main extent of the working channel. This allows, in particular, for individual adaptation of the working channel sheath to the installation space within an endoscope shaft. In one section, the outer diameter corresponds, in particular, to at least 110%, preferably at least 115%, and especially preferably at least 120% and / or at most 145%, preferably at most 140%, and especially preferably at most 135% of the inner diameter. In the other section of the working channel sheath, it has an outer diameter of at least 101%, preferably at least 106%, and especially preferably at least 110% and / or at most 138%, preferably at most 133%, and especially preferably at most 120% of the inner diameter.

[0021] It is further proposed that at least one of the plastic materials be polytetrafluoroethylene (PTFE). This advantageously improves stability, preferably while simultaneously achieving a corresponding flexibility of the working channel jacket. In particular, the plastic of one jacket layer can be polytetrafluoroethylene.

[0022] Alternatively or additionally, one of the plastic materials may be or include polyetheretherketone (PEEK) or another thermoplastic material.

[0023] Furthermore, it is proposed that the first sheath layer consists of PTFE. The second sheath layer comprises or is made of polytetrafluoroethylene, but differs from the first in that it is expanded (expanded polytetrafluoroethylene, ePTFE). PTFE is inert and has a low coefficient of friction, making it particularly suitable for the efficient transport and movement of fluids or instruments within the working channel. The material can also withstand high temperatures, such as during cleaning of the working channel in an autoclave. Expanded PTFE, in turn, exhibits improved strength properties compared to standard PTFE. It is suitable for heating and compression to vary the thickness of the second sheath layer.The combination of the PTFE and ePTFE sheath layers creates a particularly flexible yet stable working channel, the diameter and sheath thickness of which can be varied as needed and adapted to the design of the instrument.

[0024] It is further proposed that the plastic material of the jacket layer be free of pores. This can advantageously improve the fluid tightness of the working channel jacket. Preferably, the plastic material of the jacket layer has a density of less than 3 g / cm³. This is particularly true for PTFE. The density of the plastic material of the jacket layer is especially constant along the main extent of the working channel.

[0025] It is further proposed that the additional jacket layer incorporate another porous plastic material. This can advantageously improve both the flexibility and stability of the working channel jacket.

[0026] Furthermore, it is proposed that the additional sheath layer comprises another porous plastic material and is pore-free in areas of decreasing thickness. When ePTFE is used as the additional plastic material, it exhibits pores but can be pore-free in areas of reduced or decreasing thickness, for example, if it has been heated and compressed there to vary the thickness. This can be the case, in particular, in at least one further section, as described above. This section with a pore-free outer surface is then particularly suitable for bonding or other material-bonded connection with other components of the endoscope device or the endoscope itself.

[0027] Preferably, the plastic material of the additional jacket layer has a density of less than 3 g / cm³, particularly less than 2 g / cm³. The plastic material has a density of at most 1.7 g / cm³, and particularly preferably at most 1.6 g / cm³. Furthermore, the plastic material of the additional jacket layer can have a density of at least 0.6 g / cm³, preferably at least 0.8 g / cm³, and particularly preferably at least 1.0 g / cm³. The plastic material has a variable density, particularly in sections along a main extent of the working channel. The density of the plastic material of the jacket layer varies, particularly along the main extent of the working channel, and remains constant. Preferably, a variation in the density of the plastic material is coupled to a variation in the thickness of the additional jacket layer.The density may be increased, particularly in the area of ​​the further section, for example if the further plastic material has been compressed to reduce the thickness of the further jacket layer.

[0028] The density of the plastic material of the second jacket layer is particularly lower than that of the plastic material of the first jacket layer.

[0029] Furthermore, it is proposed that the endoscope device includes at least one distal endoscope tip to which the working channel is bonded by material and / or form-fitting means. The working channel can be bonded to the endoscope tip, particularly in a distal section. In this way, the working channel is fixed in its position relative to the endoscope while still remaining flexible.

[0030] In a further aspect of the invention, an endoscope with at least one such endoscope device is proposed. This can improve the manufacturing process and the service life of the endoscope. In particular, the endoscope can comprise at least two or more such endoscope devices.

[0031] In a further aspect of the invention, a method for manufacturing an endoscope device for a flexible endoscope as described above is proposed and is defined by the features of claim 17. Drawings

[0032] Further advantages arise from the following drawing description. The drawings illustrate two exemplary embodiments. The drawings, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations.

[0033] They show: Fig. 1 an open view of an endoscope device Fig. 2 a section of a working channel of an endoscope device Fig. 3 a section of an alternative working channel of an endoscope device Fig. 4 a method for manufacturing an endoscope device Description of the embodiments

[0034] Fig. 1 Figure 1 shows a schematic, open view of an endoscope device 10 in a side view of the distal end region of the device. In this case, the endoscope is designed as a flexible endoscope. Alternatively, however, the endoscope could also be designed as a rigid endoscope. Parts of the endoscope shaft 12 are not shown in the figure to allow a view of the internal components.

[0035] The endoscope device 10 forms part of the endoscope in this case. It could also form the entire endoscope. The endoscope device 10 has an endoscope shaft 12. The endoscope shaft 12 is flexible. Further components of the endoscope device 10, such as an irrigation channel, optical fibers, or the like, are arranged within the endoscope shaft 12. These are not shown for clarity. The figure shows an optical element 13 and an image sensor 14 within a distal region of the endoscope shaft 12 (left in the figure).

[0036] The endoscope device 10 has a working channel 15. The working channel 15 is arranged in the endoscope shaft 12. The working channel 15 has a working channel volume 16. The working channel 15 has a working channel sheath 18. The working channel sheath 18 encloses the working channel volume 16. The working channel sheath 18 has a constant inner diameter along a main extent of the working channel. Thus, at least one surgical instrument can be arranged in the working channel volume 16 in an operating state. The working channel 15 also runs at a slight angle from proximal (right in the figure) to distal.

[0037] The endoscope device 10 has a distal endoscope tip 19 for arranging its components. The endoscope tip 19 has a working channel receptacle 20 in which a distal end section of the working channel 15 can be positioned. The working channel 15 is bonded to the endoscope tip 19, in particular by adhesive bonding. Alternatively, the working channel 15 could also be bonded to the endoscope tip 19 by force-fit and / or form-fit.

[0038] With the working channel 15 positioned at the endoscope tip 19, the working channel sheath 18 has a variable outer diameter along the main extent of the working channel 15. The working channel sheath 18 has a distal section 21. In this case, the working channel sheath 18 tapers section by section in the distal direction. The outer diameter decreases section by section in the distal direction.

[0039] The working channel lining 18 has a proximal section 22. In the proximal section 22, the outer diameter of the working channel lining 18 is constant along the main extent of the working channel 15. Furthermore, the working channel lining 18 has a distal section 21. The distal section 21 is, in this case, a distal end section of the working channel 15. In the proximal section 22, the outer diameter is constant along the main extent of the working channel 15. The wall thickness of the working channel lining 18 is constant in the proximal section 22 along the main extent of the working channel. The outer diameter of the working channel lining 18 in the distal section 21 is at least 10% smaller than the outer diameter in the proximal section 22. The wall thickness of the working channel lining 18 is constant in the distal section 21 along the main extent of the working channel.The wall thickness in the distal section is at least 10% smaller than the wall thickness in the proximal section 22. Furthermore, the working channel lining 18 has a central section 23. The central section 23 is located between the distal section 21 and the proximal section 22. In the central section 23, the outer diameter of the working channel lining 18 decreases continuously along the main extent of the working channel 15. In the central section 23, the outer diameter of the proximal section 22 transitions continuously into the outer diameter of the distal section 21. In the central section 23, the wall thickness of the working channel lining 18 decreases continuously along the main extent of the working channel 15. In the central section 23, the wall thickness of the proximal section 22 transitions continuously into the wall thickness of the distal section 21.

[0040] The details of the working channel jacket 18 are shown in one embodiment in Figure 2The figure shows a distal section of the working channel 15, as it is used for Figure 1As described, the channel 15 runs without angulation, with a constant inner diameter, from proximal to distal (from right to left in the figure). The working channel jacket 18 has at least one jacket layer 25. Jacket layer 25 forms the inner surface of the working channel jacket 18. Jacket layer 25 comprises at least one plastic material. In this case, jacket layer 25 comprises only one plastic material. In other words, the plastic material completely forms jacket layer 25. In this case, the plastic material is polytetrafluoroethylene (PTFE). Alternatively, the plastic material could also be another thermally stable plastic that can withstand an autoclave process. The plastic material of jacket layer 25 is free of pores. The plastic material has a density of less than 3 g / cm³. Furthermore, the plastic material has a density of at most 2.4 g / cm³.In this case, the plastic material has a density of 2.2 g / m3.

[0041] In the Figures 2 and 3 The diameters and various thicknesses are indicated by arrows. D1 denotes the inner diameter of the working channel lining 18, D2 the outer diameter of the channel lining 18, d1 the thickness of the additional lining layer 30 in a proximal region, d2 the thickness of the lining 18 in a proximal region 22, d3 the thickness of the additional lining layer 30 in a distal region 21, and d4 the thickness of the lining layer 25. The other reference symbols denote the same parts as already described above. Figure 1 executed.

[0042] The jacket layer 25 has a layer thickness d4. The layer thickness d4 of the jacket layer 25 corresponds to at least 2% of the inner diameter D1 of the working channel jacket 18. The layer thickness d4 is constant along the main extent of the working channel 15. The main extent direction is in the Figure 3The working channel 15 is shown as a dashed line. The layer thickness d4 of the jacket layer has the same value in the different sections 21, 22 and 23 of the working channel 15.

[0043] The working channel jacket 18 has at least one further jacket layer 30. The further jacket layer 30 forms an outer surface of the working channel jacket 18. Jacket layer 25 and the further jacket layer 30 are in contact with each other. Jacket layer 25 and the further jacket layer 30 are bonded together by a material bond. Alternatively or additionally, jacket layer 25 and the further jacket layer 30 could also be bonded together by a form-fit bond.

[0044] The additional sheath layer 30 comprises at least one further plastic material. In the present case, the additional sheath layer 30 comprises only one plastic material. In other words, the additional plastic material forms the entire additional sheath layer 30.

[0045] The additional plastic material differs from the plastic material of the outer layer 25. In this case, the additional plastic material is expanded polytetrafluoroethylene (ePTFE). Alternatively, the plastic material could also be another thermally stable expanded plastic that can withstand an autoclave process. Due to the expansion process during its manufacture, the additional plastic material of the outer layer 30 exhibits pores. The additional plastic material has a density of at most 1.9 g / cm³. Furthermore, the plastic material has a density of at least 0.6 g / cm³. In this case, the plastic material has a density of 1.6 g / cm³, whereby the density may be higher in a section with a smaller thickness d3 of the outer layer 30, for example, if the material has been compressed.

[0046] The additional mantle layer 30 has a further layer thickness d1, d3. This additional layer thickness d1, d3 is variable along the main extent of the working channel 15. The layer thickness d1, d3 of the additional mantle layer 30 decreases section by section along the main extent of the working channel 15. In this case, the layer thickness d1, d3 of the additional mantle layer decreases section by section along the main extent of the working channel 15 in a distal direction.

[0047] In the proximal section 22, the additional jacket layer 30 has a layer thickness d1. This layer thickness d1 corresponds here to approximately 10% of the inner diameter D1 of the working channel 15. In the central section 23, the layer thickness of the additional jacket layer 30 decreases continuously. In this case, the layer thickness in the central section 23 decreases to the value d3, which corresponds to approximately half the thickness d1.

[0048] The wall thickness d2 consists of the sum of the layer thickness d4 of the shell layer 25 and the further layer thickness d2 of the further shell layer 30.

[0049] Figure 3 shows a further embodiment of the endoscope device. The same reference symbols denote the same parts as in the Figures 1 and 2 The embodiment of the working channel 15 of the endoscope device 10 differs from that shown in Figure 2This is illustrated by the fact that a distal section 21 of the working channel mantle 18 is free of the further mantle layer 30. The other dimensions and properties of the channel mantle 18 and the mantle layers 25 and 30 are as described previously. In a central section 23 of the mantle 18, however, the thickness of the further mantle layer 30 decreases along the main extent of the channel 15 from a non-zero value d1 in the proximal region 22 to a value d3 equal to zero or nearly zero in the distal section 21. The distal section 21 can therefore be free of the further mantle layer 30, and the mantle 18 is formed here only by the mantle layer 25.

[0050] Fig. 4 This shows a schematic flowchart of an exemplary procedure for manufacturing an endoscope device. The endoscope device can be designed as described previously.

[0051] The process comprises at least one process step 41. In process step 41, a working channel 15 is formed. The jacket layer 25 of the working channel jacket 18 is produced by extrusion of the plastic material or by another process.

[0052] The process comprises at least one further process step 42. In the further process step 42, the additional jacket layer 30 of the working channel jacket 18 is produced. Furthermore, the additional jacket layer 30 is bonded to the jacket layer 25 by means of a material bond. For this purpose, the additional plastic material is applied to the jacket layer 25 and then expanded by heat.

[0053] The process comprises at least one further process step 43. In the further process step 43, the thickness of the additional jacket layer 30 is varied at least section by section along the main extent of the working channel 15. For this purpose, the additional jacket layer 30 is heated and pressurized in the section. This causes the additional plastic of the additional jacket layer 30 to be compacted and thereby at least partially converted into the plastic of the jacket layer 25. For this purpose, the working channel jacket 18 can be inserted into a tapered funnel until it comes into contact with the jacket. To vary the additional jacket layer 30 or its thickness, in particular to reduce or remove it, a rotary process or an etching process, for example, can be used.

[0054] The procedure comprises a further process step 44. In this further process step 44, the working channel sheath 18 is bonded to the endoscope tip 19. For this purpose, an adhesive is applied to the working channel sheath 18 and the working channel sheath 18 is inserted into the working channel receptacle 20 of the endoscope tip 19.

[0055] The procedure may include further steps to improve the working channel and the endoscope device.

[0056] The invention is defined by the following claims.

Claims

1. An endoscope device (10) for an endoscope with at least one working channel (15) which can be arranged in an endoscope shaft, is suitable for arranging a surgical instrument therein or for transporting liquids or gases therein and has a tubular working channel sheath (18), which delimits a working channel volume (16) of the working channel (15), wherein the working channel sheath (18) has at least one sheath layer (25), which comprises at least one plastic material, and at least one further sheath layer (30), which comprises at least one further plastic material, which is different from the plastic material of the one sheath layer (25), in that the one sheath layer (25) has a constant layer thickness along the main extent of the working channel (15), and in that the further sheath layer (30) has a variable layer thickness in sections along the main extent of the working channel (15), characterised in that the plastic material of the further sheath layer (30) has pores and is free of pores in a region (23) of decreasing layer thickness.

2. The endoscope device (10) according to claim 1, characterised in that the layer thickness of the further sheath layer (30) decreases in sections along the main extent of the working channel (15).

3. The endoscope device (10) according to claim 1 or 2, characterised in that the layer thickness of the further sheath layer (30) decreases in sections along the main extent of the working channel (15) in the distal direction.

4. The endoscope device (10) according to one of the preceding claims, characterised in that the working channel sheath (18) is at least in sections free of the further sheath layer (30).

5. The endoscope device (10) according to claim 4, characterised in that the working channel sheath (18) is free of the further sheath layer (30) in a distal end section (21).

6. The endoscope device (10) according to one of the preceding claims, characterised in that the sheath layer (25) and the further sheath layer (30) lie against each other.

7. The endoscope device (10) according to one of the preceding claims, characterised in that the sheath layer (25) and the further sheath layer (30) are connected to one another in a materially-bonded manner.

8. The endoscope device (10) according to one of the preceding claims, characterised in that the sheath layer (25) forms an inner side of the working channel sheath (18) and the further sheath layer (30) forms an outer side of the working channel sheath (18).

9. The endoscope device (10) according to one of the preceding claims, characterised in that an inner diameter of the working channel sheath (18) is constant along the main extent of the working channel (15).

10. The endoscope device (10) according to one of the preceding claims, characterised in that an outer diameter of the working channel sheath (18) is variable along the main extent of the working channel (15).

11. The endoscope device (10) according to one of the preceding claims, characterised in that at least one of the plastic materials is polytetrafluoroethylene (PTFE).

12. The endoscope device (10) according to one of the preceding claims, characterised in that the one plastic material of the one sheath layer (25) is polytetrafluoroethylene (PTFE) and the other plastic material of the further sheath layer (30) is expanded polytetrafluoroethylene (ePTFE).

13. The endoscope device (10) according to one of the preceding claims, characterised in that the plastic material of the further sheath layer (30) has a density of less than 3 g / cm3, in particular less than 2 g / cm3, at least in the region of a constant layer thickness.

14. The endoscope device (10) according to one of the preceding claims, characterised in that the plastic material of the further sheath layer (30) has a lower density, at least in the region of a constant layer thickness, than that of the one sheath layer (25).

15. The endoscope device (10) according to one of the preceding claims, characterised by at least one distal endoscope tip (19) to which the working channel (15) is connected in a materially-bonded manner.

16. An endoscope with at least one endoscope device (10) according to one of the preceding claims.

17. A method for producing an endoscope device (10) according to one of claims 1 to 16, wherein in at least one method step a constant layer thickness of the sheath layer is kept constant along the main extent of the working channel (15) and a layer thickness of the further sheath layer (30) is varied in sections along the main extent of the working channel (15), characterised in that the plastic material of the further sheath layer (30) has pores and is free of pores in a region (23) of decreasing layer thickness.