Light guide or image guide components for disposable endoscopes

Abstract

The disclosure relates to diagnostic, surgical, and/or therapeutic devices for being introduced into the human or animal body or for in vitro examination of human or animal blood samples or other body cells, in particular to an endoscope or a disposable endoscope that includes at least one illumination light guide and/or image guide for transmitting electromagnetic radiation, the illumination light guide or image guide having a proximal end face for incoupling or outcoupling of electromagnetic radiation and a distal end face for incoupling or outcoupling of electromagnetic radiation. The proximal and/or distal end faces consist of plastic elements that are transparent at least partially or in sections thereof, the transparent plastic being biocompatible and/or having non-toxic properties to human or animal cell cultures for exposure durations of less than one day. This allows for the production of assemblies for disposable endoscopes, inter alia.

Claims

1. A device for being introduced into the human or animal body or for in-vitro examination of human or animal blood samples or other body cells, comprising: a guide for transmitting electromagnetic radiation, wherein the guide has a proximal end face for incoupling or outcoupling of electromagnetic radiation and has a distal end face for incoupling or outcoupling of electromagnetic radiation, wherein at least one of the proximal end face and the distal end face are elements that are made of a plastic that is at least partially a transparent plastic or are overmolded with a transparent plastic, wherein the transparent plastic is biocompatible and/or non-cytotoxic to human or animal cell cultures over exposure durations of less than one day and is selected from the group consisting of cyclo-olefin copolymers, polycarbonates, polyethylene terephthalates, perfluoroalkoxy polymers, polyvinylidene fluorides, polymethyl methacrylates, polymethyl methacrylimides, acrylic-styrene-acrylonitrile copolymers, or room temperature crosslinking silicone, hot crosslinking liquid silicones, epoxy casting resins or adhesives, thermally or UV crosslinking acrylate casting resins, polyurethane casting resins, polyester casting resins, and combinations thereof.

2. The device of claim 1, wherein at least one of the proximal end face and the distal end face of the guide further comprises a mechanical interface, wherein the mechanical interface is a ferrule contour made of a ferrule plastic, and wherein the ferrule plastic differs from the transparent plastic at least partially with respect to its material, transparency, and/or color.

3. The device of claim 1, wherein the transparent plastic has a surface roughness R.sub.a of ≤1.0 μm.

4. The device of claim 1, wherein the transparent plastic has a refractive index which substantially matches that of a core material of fibers or fiber components used in the guide, with a deviation thereto of not more than ±0.1.

5. The device of claim 1, wherein the guide comprises at least one of: a fiber bundle consisting of glass optical fibers, quartz optical fibers, or plastic optical fibers; and individual fibers made of glass, quartz, or plastic, wherein the individual fibers are enclosed at least partially or in sections thereof by any of a jacket, tube, shrink tube, or netting tube, or are protected by a shaft of the endoscope.

6. The device of claim 5, wherein the jacket is made of a jacket plastic and is an extruded cable.

7. The device of claim 6, wherein the jacket plastic is a plastic that is translucent, opaque, or colored at least partially.

8. The device of claim 5, wherein the guide consists of the fiber bundle, and the fiber bundle is flexible or semi-flexible.

9. The device of claim 1, wherein the guide consists of drawn fiber rods or pressed fiber rods and is a rigid guide.

10. The device of claim 5, wherein the fibers of the fiber bundle and/or the individual fibers are made of a Pb-free or heavy metal-free core glass and cladding glass.

11. The device of claim 5, wherein the fibers of the fiber bundle and/or the individual fibers are made of a glass system which has an acceptance angle 2α of greater than 80° for the light to be carried.

12. The device of claim 1, wherein the distal end face and/or the proximal end face with the mechanical interface comprise a ferrule that is formed separately and is fixed on a fiber bundle end or fiber rod end of the guide with an adhesive or casting resin, wherein the adhesive is a thermally curing or UV light curing adhesive which has an optical refractive index substantially matching that of the core material of the fibers or fiber components used in the guide, with a deviation thereto of not more than ±0.1, and wherein the refractive index of the ferrule is lower than that of the adhesive or casting resin.

13. The device of claim 12, wherein the ferrule comprises receptacle areas for accommodating a fiber bundle, wherein the receptacle areas comprise a conical portion transitioning into a portion that has substantially parallel side walls, wherein the ferrule furthermore has seats for electronic components, and wherein the receptacle areas at least partially surround the seats.

14. A process of making the device of claim 2, comprising the steps of: forming the distal and/or proximal end faces with the mechanical interface in the form of a ferrule by injection molding on cable sections previously cut to length so that the cable has a cable end; fixing the cable end at least at two opposite points by tools adapted to the outer contour of the cable; overmolding the cable end at least partially or in sections thereof with a first plastic; molding a geometry of the ferrule to the cable end with a second plastic; and optionally, molding the distal and/or proximal end faces with the transparent plastic in any one of said forming, fixing, overmolding, and molding steps.

15. The device of claim 1, wherein the proximal end face and/or the distal end face of the guide further comprises an active electronic component that is selected from the group of an LED, a laser diode, a sensor, a camera chip, and combinations thereof, wherein the active electronic component is integrated into the overmolded ferrules or can be fitted thereto with a snap-in connection.

16. The device of claim 15, further comprising additional glass or plastic components on the proximal end face and/or the distal end face for covering the active electronic components.

17. The device of claim 1, wherein the proximal end face and/or the distal end face is an optical element to achieve specific beam shaping.

18. The device of claim 6, wherein the extruded cable is a hybrid cable.

19. The device of claim 18, wherein the hybrid cable is a multi-lumen cable that separately routes fiber bundles, individual quartz fibers, and media in the form of gases or liquids into at least one of a fluid passage and an electrical lines.

20. The device according to claim 19, wherein the multi-lumen cable defines a flexible portion of the endoscope; or wherein the multi-lumen cable is made of a plastic that is rigid at room temperature and defines a rigid shaft of the endoscope.

21. The device of claim 18, wherein the hybrid cable is produced by a co-extrusion process so as to be transparent or opaque in segments thereof.

22. A process for making the device of claim 1, comprising the steps of: in a continuous process, overmolding a double contour ferrule on a previously extruded cable at specific intervals corresponding to a length of a mechanical interface; severing the cable at the length of the mechanical interface to produce a cable section; molding the proximal end face and/or the distal end face to the cable section in an injection molding process using clear transparent plastic.

23. The process of claim 22, wherein the cable section has a fiber bundle enclosed therein, and the fiber bundle has been offset in from an edge of the cable section, the method further comprising the step of: filling the space between the fiber bundle end and the edge of the cable section with a transparent self-leveling plastic.

24. The process of claim 23, wherein the cable section has a fiber bundle enclosed therein, and the fiber bundle has been offset in from an edge of the cable section, the method further comprising the step of: filling the space between the fiber bundle end and the edge of the cable section with a transparent self-leveling plastic with an optically transparent plastic or a prefabricated clear transparent plastic part; or inserting or fixing a glass or plastic light guide rod or fiber rod into the space between the fiber bundle end and the edge of the cable section.

25. The device of claim 1, wherein the guide is at least one of an illumination light guide and an image guide.

26. The device of claim 2, wherein the ferrule plastic is injection molded plastic.

27. The device of claim 1, wherein the device is an endoscope.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 is a schematic diagram of a disposable endoscope in the form of a flexible endoscope.

(2) FIG. 2 is a diagram of a disposable endoscope in the form of a rigid endoscope.

(3) FIG. 3 is a schematic view of an illumination light guide with an adhesively bonded distal ferrule.

(4) FIG. 4 is a schematic view of an illumination light guide with a distal ferrule molded thereto.

(5) FIG. 5 is a schematic view of an illumination light guide with a distal ferrule and an integrated camera chip.

(6) FIGS. 6a to 6c are schematic views of different arrangements of a distal end face with a camera chip.

(7) FIG. 7 is a schematic sectional view of a distal sleeve comprising an arrangement according to FIG. 6a.

(8) FIG. 8 is a schematic view of an illumination light guide with a proximal sleeve and an illuminating device integrated therein.

(9) FIG. 9 shows a highly simplified processing sequence of a manufacturing method of an illumination light guide.

(10) FIG. 10 is a schematic view of a multi-lumen cable for accommodating different components or functionalities.

DETAILED DESCRIPTION OF THE DISCLOSURE

(11) FIG. 1 schematically shows the configuration of an endoscope 1 according to the present disclosure. A simple flexible endoscope 1 is shown here in a highly simplified manner, by way of example, which comprises a handpiece 10 and a flexible section 20, the flexible section 20 being insertable into a body cavity, for example. What is schematically shown here is an illumination light guide 30 which has a proximal ferrule 40 adjacent to an illuminating device in the form of an LED 60 in the handpiece 10 and a distal ferrule 50 at the end of the flexible section 20. The light from LED 60 is injected at the end face of proximal ferrule 40 and transmitted through the illumination light guide 30 to the distal ferrule 50, and can then be emitted into the interior of the body through appropriate outcoupling optics. FIG. 1 does not show the imaging components, which may include C-MOS cameras, for example, which are integrated in the distal ferrule 50 and which electrically transmit the image information to a monitor (not shown). Another option are fiber-optic image guides that transmit the image information to a camera or directly to an eyepiece lens. Such image guides consist of several thousands of fine individual glass fibers only a few microns in thickness, which transmit the image information pixel by pixel.

(12) Depending on the type and application of the endoscope, the following typical dimensions are conceivable for such light guides: length between 100 mm and 3000 mm, typically 500 to 1000 mm, light guide diameter between 0.5 mm and 5 mm, typically between 1 and 2 mm.

(13) FIG. 2 schematically shows an endoscope 1 in the form of a rigid endoscope 1, again in a highly simplified manner. The illumination light guide 30 is routed inside a rigid shaft 25. The imaging or image-transmitting components as mentioned above are again not shown here, for the sake of clarity.

(14) The exemplary embodiments or manufacturing methods that will in particular be described below mainly relate to illumination light guides 30, but and can generally be transferred to image guides as well.

(15) FIG. 3 is a fractional view of an illumination light guide 30 with a distal ferrule 50. Here, the illumination light guide 30 comprises an extruded cable 31 consisting of a plastic jacket that encloses a fiber bundle 32.

(16) In this case, the fiber bundle is terminated by stripping the jacket from an end portion of the extruded cable 31 and fitting onto the exposed fiber bundle 32 a clear transparent ferrule that has previously been produced in an injection molding process, as a distal ferrule 50 having a receptacle area 52, and fixing the ferrule using a clear transparent resin previously introduced into this ferrule, for example in the form of a preferably quickly hot-curing or UV-curing adhesive. Thus, the distal end face 53 of the fiber bundle 32 is covered by a clear transparent plastic. This type of termination can also be applied for the proximal ferrule 40 of the illumination light guide 30. In this case, the proximal end face 43 can be covered by a clear transparent plastic.

(17) The proximal and distal ferrules 40, 50 may additionally have mechanical interfaces 44, 54 defined by the outer contour of the proximal and distal ferrules 40, 50. These may include circumferential grooves, locking lugs, notches, flanges and the like.

(18) Other than with a planar end face, these ferrules may also be designed as optical elements 51 in the form of lenses (convex or concave) or may have an irregular end face for beam shaping purposes. FIG. 3 shows, merely schematically, the distal ferrule 50 comprising an optical element 51 in the form of a lens tip formed in the injection molding process, which is useful to converge the exiting light, for example. The functionality of the incoupling and/or outcoupling ferrule, i.e. proximal and/or distal ferrule 40, 50 may be implemented in the design of the tool in a particularly cost-effective manner and allows the proximal or distal end faces 43, 53 to be terminated in an extremely cost-effective manner.

(19) The fiber bundle 32 of the illumination light guide 30 or of the image guide may comprise glass optical fibers (GOF), quartz optical fibers, or plastic optical fibers (POF) enclosed by an extruded jacket as shown in FIG. 3, or by a tube or netting tube. The plastic of the jacket of the extruded cable 31 is made of an opaque colored plastic. In a further embodiment, the fiber bundle 32 itself and/or the individual fibers thereof may have an electrically conductive coating at least partially or in sections thereof, and/or the plastic of the jacket may be made at least partially or in sections thereof from or using an electrically conductive material.

(20) The table below gives a material overview of plastics which are suitable for the jacket of the cable 31 and for the clear transparent cover of the proximal and distal end faces 43, 53 and for the proximal and distal ferrules 40, 50, respectively.

(21) Thermoplastic elastomers (TPE) are classified into groups as follows: TPE-A or TPA=thermoplastic copolyamides TPE-E or TPC=thermoplastic polyester elastomers/thermoplastic co-polyesters TPE-O or TPO=thermoplastic elastomers based on olefins, mainly PP/EPDM TPE-S or TPS=styrene block copolymers (SBS, SEBS, SEPS, SEEPS, and MBS) TPE-U or TPU=thermoplastic elastomers based on urethane TPE-V or TPV=thermoplastic vulcanizates or cross-linked thermoplastic elastomers based on olefins, mainly PP/EPDM.

(22) TABLE-US-00001 Cost Particularly Short-term classification Particularly suitable for temperature from inexpensive suitable proximal/ Permanent resistance ($) to very Basic for cable distal end temperature up to 130° C. expensive ($$$) Material designation Type plastic jacket faces resistance >130° C. (a few hours) (jacket material) Cyclo-olefin copolymer COC transparent X Ethylene tetrafluoroethylene ETFE transparent X X $$$ copolymer Fluoroethylene propylene FEP transparent X X $$$ Polycarbonate PC transparent X $ Polyethylene PE transparent X $ Polyethylene terephthalate PET transparent X Perfluoroalkoxy polymers PFA transparent X X $$$ Polymethyl methacrylate PMMA transparent X Polymethyl methacrylimide, PMMI transparent X Acrylic Polypropylene PP transparent X $ Polyvinyl chloride PVC transparent X $ Polyvinylidene fluoride PVDF transparent X X $$$ Styrene-ethylene-butylene SAN transparent X $ block polymers (see TPE-S) Styrene-ethylene-butylene- SEBS slightly X $ styrene block polymers (see translucent TPE-S) Styrene-ethylene-butylene SEB slightly X $ block polymers (see TPE-S) translucent Tetrafluoroethylene- THV transparent X $$$ hexafluoropropylene- vinylidene fluoride Thermoplastic co-polyamides TPE-A transparent X X $$ Thermoplastic elastomers TPE-E transparent X $$ Styrene block copolymers TPE-S transparent X $ Thermoplastic vulcanizates or TPE-V beige X X $$ cross-linked thermoplastic elastomers based on olefins, mainly PP/EPDM, or vulcanized (cross-linked) PP/EPDM compounds Thermoplastic polyurethane TPU transparent X $$ Silicone HT transparent X X $$ (hot cross-linking) silicone Silicone (cross-linking @ RT transparent/ X X $$ room temperature) silicone translucent Liquid Silicone Rubber LSR transparent X X X $$$ (thermally, condensation crosslinking or UV curing) Epoxy casting resins or transparent X partially $/$$ adhesives Acrylic casting resins or transparent X $ adhesives (thermally or UV curing) Polyurethane casting resins transparent X $ or adhesives Polyester casting resins or transparent X $ adhesives

(23) Especially the plastic types TPE-E, TPE-V, and TPE-U are particularly interesting for extrusion, since they exhibit very good extrudability and in particular are well or even very well suited for medical applications. With regard to cost-effective production, these materials moreover have comparatively low material costs. Inexpensive plastics such as PVC, compounds and blends made of PP, PE, TPE-S (SEBS) sometimes have considerable deficits, particularly in terms of temperature resistance. They mostly cannot be employed above 100° C. However, the temperature requirements for disposable endoscopes are significantly lower, so that these materials are particularly suitable for this application due to their low material costs and easy processing. The otherwise commonly required minimum temperature resistance of greater than 133° C. to 137° C., which corresponds to the temperature range during autoclaving of reusable or reprocessable medical devices or components is not necessary in this case, since the processes usually employed as the sterilization processes for disposable medical products are conducted in a temperature range from room temperature to not more than 60° C. An example of a commonly used sterilization method is ethylene oxide fumigation.

(24) The group of inexpensive and medium-priced plastics is usually available in a wide range of elasticity and hardness specifications or can be produced by mixing multiple types of plastics into a poly-blend of desired performance. An advantage over the “expensive” plastics such as FEP, PVDF is that they can be used to produce illumination light guides 30 with virtually identical properties but with different flexibility.

(25) Although the expensive plastics such as FEP, PFA, PVDF can be employed universally and in particular exhibit high permanent temperature resistance, often in combination with high chemical resistance, they cannot but to a very limited extent combined with other plastics or mixed into a poly-blend in order to increase flexibility, for example.

(26) All of the plastics mentioned have more or less already been employed for medical products.

(27) In addition to PC and PA, COC is also very well suited as a material for the transparent ferrules, since it is of high optical quality with regard to high transparency and low haze and is in particular used for syringes and pharmaceutical packaging. These materials are in particular also available as biocompatible variants.

(28) With regard to the formation of a flat surface as the proximal or distal end face 43, 53, it is also possible to use casting resins in an advantageous embodiment, in particular low-viscosity casting resins that have particular self-leveling properties.

(29) As an alternative to an extrusion process, the glass fiber bundles or plastic optical fibers may as well be encased in a thin-walled tube or in a shrink tube for their protection. In the case of shrink tubes, advantageously, extremely thin-walled shrink tubes can be used (e.g. PET shrink tube of 6 μm wall thickness). Thin-walled netting tubes made of glass silk or plastic silk are also conceivable.

(30) Most preferably for medical applications, the glass fibers may be made of a Pb-free or heavy metal-free core glass and cladding glass, which is particularly favorable in view of the RoHS and REACH regulation requirements and medical approval. Such glass systems for producing Pb-free or heavy metal-free fibers have been described in documents WO 2013/104748 A1 and DE 102007063463 B4, inter alia, and are known from the present applicant under the name SCHOTT PURAVIS®. Rigid Pb-free or heavy metal-free fiber-optic elements are described in DE 10 2013 208838 B4. Particularly suitable for applications in the field of endoscopy are glass fibers with high NA values, i.e. with acceptance angles 2α>80°, preferably 2α>100°, in order to allow for wide illumination on the one hand and optimal incoupling of light by LEDs on the other. Such fibers are known under the names of SCHOTT PURAVIS® GOF85 or GOF120, for example.

(31) FIG. 4 shows a portion of an alternative approach for an illumination light guide 30 with a distal ferrule 50, which may be similarly implemented for the proximal ferrule 40 as well.

(32) To this end, for example, the fiber bundles are previously extruded, as already described in conjunction with FIG. 3, that is to say the fiber bundle 32 is jacketed with a plastic to form a cable 31, cut to length and then subjected to an injection molding process in which the cable sections are directly overmolded with the transparent plastic to thereby form a ferrule, i.e. distal ferrule 50 in this case. In order to prevent the fiber ends from fanning out, the cable end may have to be grasped at least at two opposite points by semicircular collets and at least partially overmolded. A second injection overmolding process may then be provided to overmold the final ferrule geometry. This makes it possible to form a clear transparent cover for the distal end face 53 on the one hand, optionally with integrated optical functionality in the form of shaped lens elements (optical element 51), and to form a mechanical interface 54 using another plastic which may optionally be a different type of plastic and may even be opaque. The same applies to proximal ferrule 40 which may be provided with a clear transparent cover for the proximal end face 43, optionally with integrally molded optical elements 41, and with a mechanical interface 44 using these method steps.

(33) FIG. 5 shows a variant of the embodiment shown in FIG. 3. Again, distal ferrule 50 is illustrated here by way of example, attached on illumination light guide 30 shown as an extruded cable 31 including the fiber bundle 32. Here, distal ferrule 50 has a central area in which a camera chip 70 (C-MOS chip) may be integrated, for example, in which case the fiber bundle 32 of illumination light guide 30 is routed and arranged around the camera chip 70 in an annular arrangement, an at least partially annular arrangement, or in at least two sub-strands. For this purpose, the receptacle area 52 for the fiber bundle 32 conically widens correspondingly. Also, optical elements 51 may be integrally molded when producing the ferrule, or may be additionally applied in a subsequent adhesive bonding process. In this way, optimal illumination of the tissue area to be examined can be achieved on the one hand, especially shadow-free illumination, and on the other hand this allows to provide imaging optics for the camera chip 70. Furthermore, conceivable is the integration of sensor components such as photodiodes or the like, for detecting particular wavelengths of the light scattered back from the surface to be examined.

(34) FIGS. 6a to 6c schematically show typical arrangements of the distal end face 53 of the illumination light guide 30 in combination with a camera chip 70, with distal ferrule 50 representing the termination of the shaft 25 of endoscope 1 in these examples. FIG. 6a shows an arrangement in which the camera chip 70 is essentially surrounded by distal end face 53. FIG. 6b shows an essentially U-shaped distal end face 53. FIG. 6c shows an exemplary arrangement in which the camera chip 70 is flanked by a pair of diametrically opposed D-shaped distal end faces 53. Furthermore, 3- or 4-part distal end faces 53 are conceivable, surrounding the camera chip 70 in the form of circular or oval or kidney-shaped exit faces.

(35) The geometric arrangement is predetermined correspondingly by the configuration of the distal ferrule 50. Such ferrules can be produced particularly cost-effectively by injection molding.

(36) By way of example, FIG. 7 shows a sectional view of a distal ferrule 50 corresponding to the arrangement of distal end face 53 and camera chip 70 as shown in FIG. 6a.

(37) As an example, distal ferrule 50 is shown here as terminating a rigid shaft 25 of the endoscope 1, which shaft may be a stainless steel tube, for example. Distal end face 53 is arranged substantially annularly around the centrally arranged camera chip 70. The light emitted from the distal end face is reflected by a tissue surface 90 to be examined, for example, and is captured by camera chip 70. Camera chip 70 is covered for protection, and the cover may be in the form of an optical element 51, such as a converging lens. An optical element 51 in the form of a multi-lens arrangement is likewise conceivable. Camera chip 70 is electrically connected to electrical lines 210 which are routed through a feedthrough 56 in distal ferrule 50 and into the interior of shaft 25. The fiber bundle 32, here consisting of glass fibers with a high NA (acceptance angle 2α>100°), is fanned out to form a ring and is fixed in an annular receptacle area 52 provided about feedthrough 56. This receptacle area 52 has walls that are nearly parallel to one another in order to allow the fibers to be oriented in parallel to one another. Adjoining the receptacle area 52, distal ferrule 50 has conically shaped areas in order to facilitate threading of the fibers. Inside the shaft 25, the fiber bundle 32 is surrounded by a protective sheath 33, which may be in the form of an extruded jacket, a netting tube, or a shrink tube. Given the very small installation space inside shaft 25, it is particularly advantageous if, for example, a thin-walled PET shrink tube is used as the protective sheath. Such shrink tubes have a wall thickness of <10 μm. Distal ferrule 50 may have further mechanical interfaces 54 on its outer contour, for example in the form of a collar, or a diameter step as shown, for joining the distal ferrule 50 to the shaft 25. Moreover, several adhesive bonding areas 55 are provided, on the one hand for fixing the fibers of the fiber bundle 32 and on the other hand for fixing the camera chip 70 or for additionally sealing the feedthrough 56 for the electrical lines 210. With regard to process times and thus costs, it is particularly advantageous if the entire distal ferrule 50 is made of a clear transparent plastic such as PC or PMMA, and if a UV-curing adhesive is used as the adhesive or as a casting resin for the adhesive bonding areas 55. The adhesive or casting resin that is in particular used in the receptacle area 52 for fixing the fibers has an optical refractive index which is substantially matched to that of the core material of the fibers, with a deviation of these refractive indices of at most ±0.1, preferably at most ±0.05, while the refractive index of the ferrule is slightly lower than that of the adhesive.

(38) It will be apparent that such an embodiment with the features as mentioned above is likewise conceivable for a proximal ferrule 40, in which case an LED 60 can be integrated instead of the camera chip 70.

(39) In an embodiment not shown, it is conceivable that the camera chip 70 is mounted on the rear side of distal ferrule 50 and that the distal end face 53 forms a cover. In this way, improved electrical insulation can be achieved without an additional covering element.

(40) FIG. 8 shows a proximal ferrule 40 on the illumination light guide 30, in which an LED 60 along with an LED controller unit 70 is integrated into the proximal ferrule 40. In this way, it is in particular possible to implement a space-saving light source. Here, LED 60 and LED controller unit 70 are integrated in a proximal ferrule 40 that has been produced separately, as described in conjunction with FIG. 3, and the end of fiber bundle 32 is assembled or fixed in a receptacle area 42 formed in proximal ferrule 40. The proximal end face 43 may be provided with a clear transparent cover which may be in the form of a condenser lens or a structure enclosing the LED chip, in order to provide for optimum injection of light into the fiber bundle 32.

(41) Alternatively, as illustrated by a highly simplified process sequence in FIG. 9, a continuous process may be implemented during which a previously extruded cable 31 including the fiber bundle 32 is rewound from an unwinder onto a winder, and the rewinding is stopped at specific intervals and a plastic double ferrule is overmolded thereto by injection molding using a first injection molding tool 100. At this location, a double ferrule is overmolded around the cable 31 in a positively fitting manner without an intermediate layer, which double ferrule is severed together with the cable 31 by severing means 110 in a subsequent cutting process. This is also conceivable directly following the extrusion process, if appropriate measures are provided to adjust or compensate for the processing rates, for example a buffering zone for intermediate storage of the extruded cable. The so terminated cable sections which later correspond to the illumination light guide 30, can then be overmolded in further steps using a second and a third injection molding tool 120, 130, to produce the final ferrule design and in particular using an optically clear transparent plastic, so that simple entry and exit optics (optical elements 41, 51) can be provided on the proximal or distal end faces 43, 53 of the illumination light guide 30 in this way, inter alia. As an alternative, this may also be achieved in an adhesive bonding process, which may also be employed to mount further components such as, e.g., C-MOS cameras or sensors. The advantage hereof is that, on the one hand, firm ferrules can be produced and that in particular the fixation in the tool for the second final overmolding process is made easier by forming respective mechanical interfaces 44, 54. This permits to achieve tight bundle terminations. In this way, high volumes of simple illumination light guides 30 can be obtained very cost-effectively, which is of particular interest for disposable applications and also for consumer applications.

(42) According to a preferred embodiment, cables known as multi-lumen cables 200 can be produced, as schematically shown in FIG. 10. Such cables may include fiber bundles 32, quartz fibers 220, electrical lines 210, and a fluid passage 230 for carrying media such as gas (e.g. nitrogen), water, medications, and rinsing liquids. The quartz fibers 220 may be used for optical data transfer, for example, or for controlling purposes. Multi-lumen tubes have already been known from literature. A particular advantage thereof lies in the integration of light- and power-carrying components, which provides for high functionality in very restricted space. It can furthermore be envisaged for the cables, inter alia, to be made in a co-extrusion process so as to selectively comprise transparent or opaque segments so that they can moreover fulfil lighting or optical detection tasks.

(43) Another alternative for an inexpensive termination are crimped ferrules as described in DE 10 2004 048741 B3. As an alternative thereto, plastic crimp or latching sleeves may be used, which are prefabricated by an injection molding process and formed with a folding hinge (living hinge) so as to be foldable. Such ferrules are then snap-fitted around the end of the cable section of the extruded cable and can then be filled with optically transparent adhesive in a casting or injection molding process. UV curing adhesives are again advantageous in this case. Besides snap-fitting it may also be envisaged for the ferrules to be fixed on the cable by laser welding or ultrasonic welding.

(44) Another method arises based on the elastic properties of a cable. In this case, it is intended to cut an extruded cable and then to elongate the cable jacket and to fill the resulting cavity with optically clear adhesive or to insert into and fix in the cavity a prefabricated clear transparent plastic part or a glass or plastic light guide rod or fiber rod. Additionally, a fastening feature may be formed by intentionally reshaping the exposed cable sections. Thermoplastic elastomers (TPE) or elastomers such as rubber or silicone are particularly suitable here as the jacket material.

(45) Another alternative for cost-effective termination of light guides may comprise partial heating of a cable filled with gel so that the gel cures there and the cable can then be cut and optionally be reshaped or ferrules can be molded thereto. The cable may also be produced by co-extrusion and may have a transparent section along the axis of the cable, through which the gel can then be selectively cured in sections thereof using UV light. This is another option for implementing a continuous termination process.

LIST OF REFERENCE NUMERALS

(46) 1 Endoscope

(47) 10 Handpiece

(48) 20 Flexible section

(49) 25 Shaft

(50) 30 Illumination light guide

(51) 31 Cable

(52) 32 Fiber bundle

(53) 33 Protective sheath

(54) 40 Proximal ferrule

(55) 41 Optical element

(56) 42 Receptacle area

(57) 43 Proximal end face

(58) 44 Mechanical interface

(59) 50 Distal ferrule

(60) 51 Optical element

(61) 52 Receptacle area

(62) 53 Distal end face

(63) 54 Mechanical interface

(64) 55 Adhesive bonding area

(65) 56 Feedthrough

(66) 60 LED

(67) 70 Camera chip

(68) 80 LED controller unit

(69) 90 Tissue surface

(70) 100 1.sup.st injection molding tool

(71) 110 Severing means

(72) 120 2.sup.nd injection molding tool

(73) 130 3.sup.rd injection molding tool

(74) 200 Multi-lumen cable

(75) 210 Electrical lines

(76) 220 Quartz fibers

(77) 230 Fluid passage