Optical guides, endoscopes, methods for manufacturing and using optical guides

Abstract

The present invention relates to an optical guide 1, 19, 20 having a plurality of optical single fibers 3 bundled together 2 and at least one sheath 4, 5 covering at least one segment of the outer periphery of the bundle, the at least one sheath 4, 5 being made of ceramic.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to European Patent Application No. 19184544.5, filed on July 4, 2019, entitled "Optic light guide, endoscope, method for producing and using an optic light guide", the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present invention relates to an optical guide having a bundle of a plurality of optical single fibers and at least one sheath covering at least one segment of the outer periphery of the bundle.

[0004] The present invention also relates to an endoscope having an optical guide.

[0005] The present invention further relates to a method for manufacturing an optical guide.

[0006] Finally, the present invention relates to the use of an optical guide for the purpose of guiding light between the proximal end and the distal end of an axis. Background Technology

[0007] Light guides of the types described above are known. For example, they are used in endoscopes to guide light from the proximal to the distal end of the endoscope axis for purposes such as illuminating points within a cavity to be examined. Alternatively, a light guide can guide an image captured at the front of the endoscope (field of view) to an image sensor at the proximal end of the endoscope (e.g., in the endoscope handle). In this case, the light guide directs light reflected from the tissue to the imager.

[0008] For the purpose of manufacturing optical light guides, it is common practice to securely surround a bundle of multiple optical fiber monofilaments with a sheath, allowing the monofilaments to be packed at the maximum possible density. Subsequently, for example, if the sheath is an end sheath, the bundle can be trimmed to the desired length and ground and / or polished to form flat ends. The sheath thus constitutes the fiber sleeve of the optical light guide.

[0009] However, a recurring problem with existing optical guides is that they occupy a relatively large amount of installation space, for example, when they are installed in an endoscope. Since endoscopes are often introduced into narrow cavities for examination, it is desirable to design endoscopes with the narrowest (or thinnest) possible endoscope axis. Because the guide is arranged along the longitudinal axis of the endoscope axis, the diameter of the axis is largely limited by the thickness of the optical guide.

[0010] However, at the same time, the weight of the optical light guide should be as small as possible, since the user often also has to lift the weight of the light guide mounted in the endoscope, for example, when using the endoscope. Furthermore, the present application can provide, if necessary, the alignment of the front side (light entry surface and / or light exit surface) formed by the light guide in the region of the endoscope tip which is not perpendicular to the longitudinal axis of the light guide or endoscope shaft, but transverse to the light guide or endoscope shaft (or at an angle thereto). In this regard, reflective surfaces (e.g. mirrors) are often used, however, this takes up additional installation space and sometimes increases the overall weight of the optical light guide.

[0011] It is an object of at least some embodiments of the present application to improve the use properties of previously known optical light guides and / or endoscopes of the above-mentioned type. SUMMARY

[0012] According to the present application, an optical light guide according to claim 1 is provided. In particular, according to the present application, an optical light guide of the above-mentioned type is provided, wherein the at least one sheath is made of ceramic. This ceramic has the advantage that the shape can be chosen very easily and the material of the sheath is sufficiently strong and hard to provide stability and robustness. Furthermore, the ceramic sheath has a relatively smooth surface compared to other materials (e.g. metal) and facilitates the insertion and setting of the required bundle density as a bundle of single fibers.

[0013] Furthermore, ceramic is an electrically non-conductive material, which means that the sheath provides additional insulation for electronic components (e.g. imaging modules or image sensors). Thus, no additional insulator for the purpose of insulating the sheath is required, which would take up additional installation space.

[0014] In the following, advantageous embodiments of the present application are described, which can be combined individually or with features of other embodiments, optionally in combination with the features of claim 1.

[0015] According to an advantageous embodiment, the at least one sheath can follow a non- straight line (although a straight line is also possible). For example, the sheath can follow an angled route to allow for a radiation at a determinable angle to the longitudinal axis of the endoscope and / or the optical light guide. Furthermore, the advantage of the non-straight design of the sheath is that a change in the direction of the sheath can be used to avoid obstacles. Especially in endoscopes, the non-straight design allows for a minimization of the installation space taken up by the optical light guide, since the change in the direction of the sheath allows for the fiber bundle to be routed around obstacles within the endoscope. This allows, inter alia, for the endoscope to be designed with a diameter as small as possible to be introduced into particularly narrow cavities.

[0016] According to another advantageous embodiment, the optical light guide can comprise at least two sheaths, each of the at least two sheaths comprising one section of the outer periphery of the bundle. For example, two sheaths can be arranged at one end of the bundle and / or enclosing the bundle at the end thereof, respectively. The sheaths thus more effectively prevent the single fibers of the bundle from spreading apart. Furthermore, the sheaths can be designed differently, meaning that the directional alignment or change of the individual sections of the bundle can be set (or set) individually. Furthermore, this allows for the maximum use of the existing installation space.

[0017] In order to reduce the weight while at the same time ensuring that the fiber sleeve of the bundle has sufficient quality, sections of the bundle can be designed without a sheath sleeve. In particular, the present application provides the two sheaths described above, in particular enclosing the two end sections of the bundle, while the intermediate (or central) section located between the ends is designed without a sheath, i.e. without a sleeve.

[0018] In order to redirect the light around one or more obstacles by means of the at least one sheath, the at least one sheath can comprise at least one directional change. In order to redirect the light around several obstacles, the at least one sheath can comprise at least two or more directional changes. For example, a directional change in the sense of the present application can be achieved by a non-straight passage formed by the sheath and guiding the bundle, for example a bend, a curve, a deflection and / or a stop. Thus, no additional installation space is required to redirect the light around obstacles in the installation space for the optical light guide. In fact, the sheath can prevent the bundle from spreading apart into single fibers in the area of the directional change by firmly enclosing the single fibers in this area and / or compensate for the tension in the bundle of single fibers caused by the directional change, so that they are as close together as possible.

[0019] According to another advantageous embodiment, the at least one sheath can comprise at least one section of the cross section that changes its shape along its course. The shape of the cross section can be arbitrarily adjusted depending on the given installation space situation in order to facilitate the redirection of the light around obstacles located in the installation space. The cross sectional area of the cross section that changes its shape can remain the same for the purpose of keeping the amount of light to be guided at a level as constant as possible. Some examples of possible cross sectional shapes include: spherical, oval, angular, non-circular, circular and / or semi-circular.

[0020] For the purpose of keeping the single fibers in the bundle as close together as possible and filling the gaps between the single fibers, another advantageous embodiment provides at least one space between the single fibers enclosed by the at least one sheath that is at least partially filled with an adhesive that stabilizes the single fibers.

[0021] In particular, the advantageous embodiments provide for a gap surrounded by the sheath to be completely filled with an adhesive. Such an adhesive can be, for example, a chemically hardening adhesive, in particular an epoxy resin adhesive. The adhesive allows a particularly good control of the time of the hardening process. In its hardened state, the adhesive is preferably transparent and / or light-conducting.

[0022] According to a further development, in order to achieve a particularly firm (or good) fixation of the bundle within the sheath, in particular without the sheath being squeezed after insertion of the bundle, it can be provided that the cross-section of the sheath, for example the aforementioned cross-section, narrows along its course. Alternatively or additionally, it can also be provided that the end regions of the sheath comprise a cross-sectional area which is smaller than the area, for example the central area, located at a distance from the end regions. This allows the bundle to be inserted into the sheath, wherein the individual fibers in the bundle are compacted at the narrow points formed by the sheath and are thus firmly surrounded (or held) by the sheath. It can thus be provided that the aforementioned cross-sectional area of the sheath remains constant, with the exception of the end regions and / or the narrow points.

[0023] According to a further aspect of the present application, there is provided an endoscope comprising an optical light guide, such an endoscope being of the type described and claimed herein, wherein light can be guided through the optical light guide between the distal end of the shaft and the proximal end of the shaft, or during use of the endoscope. The optical light guide can be used to guide light from a light source arranged at the proximal end of the shaft to the distal end of the shaft. The optical light guide can also be used to guide light captured at the distal end of the shaft to the proximal end of the shaft. The optical light guide allows for a redirection of light around opaque obstacles in the installation space formed in the shaft, which means that a linear and / or straight arrangement of the bundle of individual fibers is not required or provided in the shaft of the endoscope. This has the advantage that the overall diameter of the shaft can be kept as small as possible, since the overall installation space required for arranging the optical light guide is smaller.

[0024] The present application also relates to a method for manufacturing an optical light guide, for example as described and claimed herein, wherein the optical light guide comprises a plurality of light guiding bundles of individual fibers and at least one sheath comprising at least one section of the outer periphery of the bundles, wherein the bundles comprising individual fibers are inserted into the sheath made of a ceramic material. The interspaces between the individual fibers surrounded by the at least one sheath can be at least partially filled with an adhesive. This means that the advantages described above with respect to the embodiments of the optical light guide apply to the same extent to the method. The method thus allows for the manufacturing of a robust optical light guide which occupies little installation space. Optionally, the required installation space can be further reduced by means of the sheath by, for example, providing a change of direction of the bundles around obstacles.

[0025] Finally, the invention relates to the use of an optical light guide as described and claimed herein in an endoscope. For example, it can be provided, by means of the optical light guide, to guide light (for illumination) from a light source at the proximal end of an endoscope shaft to the distal end of the shaft. Alternatively or in addition, by means of the optical light guide, it can be possible to guide light captured at the distal end of the shaft to the proximal end of the shaft. In particular, the single-fiber bundle of the optical light guide can be arranged in a non-linear manner (i.e. not along a straight line) within the mounting space of the shaft in order to be able to indirectly redirect light within the mounting space around non-transparent obstacles without wasting mounting space.

[0026] In the following, the invention will be described in more detail by means of a plurality of exemplary embodiments; however, the invention is not restricted to these exemplary embodiments. Further exemplary embodiments will be apparent from the features of the one or more claims and their combinations with the features of the exemplary embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0027] The drawing shows:

[0028] Figure 1 is a schematic longitudinal representation of an endoscope comprising an optical light guide, wherein light is guided by means of the optical light guide from a light source arranged at the proximal end of the shaft to the distal end of the shaft,

[0029] Figure 2 is a longitudinal detail view of an endoscope tip having two separate optical light guides arranged at a distance from each other, between which optical light guides a light channel for image generation is arranged, wherein the optical light guides each perform at least one directional change and the viewing direction of the endoscope is angled relative to the longitudinal axis of the endoscope shaft,

[0030] Figure 3 is Figure 2 is a front view of the endoscope tip in the

[0031] Figure 4 is a longitudinal representation of an alternative embodiment of a sheath of an optical light guide, wherein the sheath is angled downward along its course (length) and narrows along its course,

[0032] Figure 5 is a schematic representation of a further alternative embodiment of a sheath of an optical light guide, wherein the sheath and / or the optical light guide comprises a plurality of changes in the direction and shape of the cross-section of the sheath (see intersection lines A, B and C) along the course of the sheath,

[0033] Figure 6 shows Figure 5Cross-section of the intersection of the sheaths of the letter A, B and C, in which the shape of the cross-section of the sheaths changes along its course from a circle to an oval to a circle again. DETAILED DESCRIPTION

[0034] Figure 1 An endoscope is shown overall with the reference 100, which has an endoscope shaft 12 comprising optical light guides 1, 19, 20. The endoscope 100 can comprise, for example, a relatively short optical module (e.g. a CIT "tip-chip" endoscope).

[0035] The optical light guides 1, 19, 20 are arranged along the longitudinal axis of the shaft 12 from the distal end 13 to the proximal end 14 of the endoscope shaft 12. This allows light to be guided through the endoscope shaft 12 by the optical light guides 1.

[0036] The optical light guides 1, 19, 20 comprise a bundle 2 of a plurality of light guide single fibres 3, wherein the single fibres 3 are bundled by being surrounded at least in sections by a sheath 4, 5. The inner guiding channel 21 of the sheath 4, 5 depends on the number of single fibres in the bundle 2 and the diameter of each fibre. At least a portion of the guiding channel 21 of the sheath 4, 5 is typically designed such that the bundle 2 of single fibres is held or clamped by (or fixed to) the inner wall of the guiding channel 21. As will be described further below, the inner guiding channel 21 can be tapered to facilitate insertion of the fibres therein. The present invention can provide for a wall thickness of the sheath 4, 5 to be as small as possible, for example a maximum of 500 pm, in particular a maximum of 400 pm, in particular a maximum of 300 pm, in particular a maximum of 200 pm, in particular a maximum of 100 pm.

[0037] The sheath 4, 5 is partially or entirely made of a ceramic material. The ceramic material allows for a particularly simple shape of the given sheath 4, 5. At the same time, the sheath 4, 5 can be made sufficiently hard to achieve sufficient stability and robustness, for example by running a sintering process known per se, such that the shape of the sheath 4, 5 does not change during installation or during use. Furthermore, the ceramic sheath 4, 5 has a particularly smooth surface, which allows for the introduction of the single fibres 3 of the bundle 2 into the sheath 4, 5 and facilitates the achievement of a given packing density of the single fibres 3.

[0038] The present invention can provide for the manufacture of the sheath 4, 5 to be manufactured in what is known as an LCM process (lithography-based ceramic production).

[0039] Figure 2 A detailed view is shown of a longitudinal section of the tip 18 of the endoscope 100, which comprises two optical light guides 19, 20 arranged at a distance from each other and along the longitudinal axis of the endoscope shaft 12.

[0040] Figure 3A top view (or front view) of the tip 18 of the endoscope is shown. Figure 2 A top view (or front view) of the tip 18 of the endoscope is shown.

[0041] The optical channel 17 for image generation is arranged between the optical light guides 19, 20. Through the optical channel 17 for image generation, an image of a scene within the field of view of the endoscope 100 can be recorded and transmitted to an image sensor.

[0042] In Figure 1 , Figure 2 and Figure 3 In the depicted embodiment, the optical light guides 1, 19, 20 are used to guide light from the light source 16 (shown in Figure 1 ) from the proximal end 14 to the distal end 13 of the shaft 12 in order to be able to illuminate a scene. Light reflected from the scene is captured by the optical channel 17 (as shown in Figure 2 ) to generate an image. In alternative embodiments, the optical light guides 1, 19, 20 can be used to capture light from a scene and guide the captured light from the distal end (13) of the endoscope shaft 12 to the proximal end 14 of the endoscope shaft 12.

[0043] As shown in Figure 1 , Figure 2 , Figure 4 and Figure 5 The at least one sheath 4, 5 can follow a non-straight line. This means that the sheath 4, 5 and in particular the guide channel 21 formed by the sheath 4, 5 does not follow an exact straight line, but a non-straight line. Thus, the angle of the illumination direction relative to the longitudinal axis of the optical light guide 1 and / or the shaft 12 can be set in a particularly precise manner by the sheath 4, 5. In particular, since the sheath 4, 5 is made of a hard (solid) ceramic material that does not bend during use, the orientation of the end of the single fiber bundle can be fixed in the desired orientation because the fiber bundle conforms to the line followed by the ceramic sheath 4, 5.

[0044] The first optical light guide 1, 19 comprises a sheath 4, 5 following an angled line, which means that the exit direction in the light exit area 23 extends transversely to the longitudinal axis of the shaft 12 and / or the optical light guide 1, 19 (at an angle).

[0045] The second optical light guide 1, 20 comprises a sheath 4, 5 following a curved line, which means that the bundle 2 is guided around an obstacle in the installation space of the shaft 12. The curved line of the sheath 4, 5 is also arranged such that the exit direction in the light exit area 23 extends transversely to the longitudinal axis of the shaft 12 and / or the optical light guide 1, 20 (at an angle). In this embodiment, the two optical light guides 19, 20 share the same exit direction.

[0046] Each optical light guide 1, 19, 20 comprises at least one sheath 4, 5. With regard toFigure 1 In an alternative embodiment depicted herein, the present invention aims to include at least a first sheath 4 and a second sheath 5 in the optical guide 1. The first sheath 4 surrounds the single fiber 3 of the bundle 2 at a first end 6, and the second sheath 5 surrounds the single fiber 3 of the bundle 2 at a second end 7. The intermediate or central section between the two ends 6 and 7 is not surrounded by the sheaths 4 and 5. This helps to minimize the overall weight of the optical guide.

[0047] As in Figure 2 and Figure 5 As clearly seen, the sheath may include one or more changes in direction 8 to allow the beam 2 to be routed around an obstacle (e.g., in the mounting space of the endoscope axis 12) or to achieve a desired exit direction of light. For example, the change of direction can be achieved by giving a specific shape to the sheath and / or the guide channel 21 formed by the sheaths 4, 5. The specific shape may be, for example, an inflection point, a curve, a material stop, or a spiral.

[0048] Figure 5 Alternative embodiments of sheaths 4 and 5 are shown, which include multiple changes in direction 8 to achieve a tortuous and / or nearly tortuous route for the bundle 2 through sheaths 4 and 5.

[0049] also, Figure 5 The optical guide 1 shown includes sheaths 4 and 5, which have cross-sections 9 whose shape changes along their path. In particular, the cross-section 9 of the sheaths 4 and 5 refers at least to the cross-section of the guide channel 21 of the sheaths 4 and 5. Figure 6 Three different cross-sectional shapes of the sheath 4 are shown, among which... Figure 5 The intersecting lines depicted and marked with the letters A, B, and C show where sheaths 4 and 5 intersect in each case.

[0050] For example, cross-sections A and C in the example are circular in shape, while cross-section B has an oval shape.

[0051] However, regardless of the shape of cross section 9, the surface area of ​​the corresponding cross-sectional areas of cross sections 9, A, B, and C of the sheaths 4 and 5 can remain the same. If the cross-sectional areas do indeed remain the same, the amount of light guided can be unaffected by changes in the shape of the cross section of beam 2. Different cross-sectional shapes can be used to optimize the use of available installation space. For example, a non-circular shape can be used at narrow points to avoid having to make the outer diameter of the optical guide 1 at that point smaller.

[0052] The gaps between the individual fibers 3 of bundle 2 can be at least partially filled with an adhesive in the area surrounded by sheaths 4 and 5. For example, the adhesive can be a chemically curable adhesive. This makes it easier to stabilize the individual fibers 3, at least in the area of ​​sheaths 4 and 5. This adhesive also helps to secure the fiber bundle to the sheaths 4 and 5.

[0053] For example, such as Figure 4 As shown, in order to make it as easy as possible to set the packing density of the bundle 2 through the sheaths 4 and 5, the cross section 9 of the guide channel 21 of the sheaths 4 and 5 can be narrowed along its route.

[0054] As an alternative or additional implementation, at least one end region 10 of the sheaths 4 and 5 may include a cross-sectional region smaller than the region located at a certain distance from the end region 10. For example, the region located at a certain distance may be the central region 11 of the sheaths 4 and 5.

[0055] At the distal end 13 of the endoscope axis 12, a frontal view defining the field of view of the endoscope tip 18 is formed (see...). Figure 3 In each case, the front side includes a cover glass 22 facing outwards, covering the beam 2, which is arranged in the light emitting region 23 of the beam 2. The cover glass 22 allows for an airtight seal, for example, to prevent moisture from entering.

[0056] In order to achieve light guiding with minimal loss via the optical guide, the present invention can provide the end face of the single fiber 3 of the bundle, which, if not already polished, is then polished. For example, this step can be performed before mounting the cover glass 22 in the light emitting region 23.

[0057] In this paper, the advantage of using ceramic sheaths 4 and 5 is that the ceramic sheaths have greater strength and heat resistance, which means that the end face of the single fiber 3 can still be polished or ground after it has been surrounded by sheaths 4 and 5.

[0058] Furthermore, sheaths 4 and 5 can be more easily modified during finishing steps, such as grinding and / or polishing.

[0059] Therefore, the present invention specifically relates to an optical guide 1, 19, 20 having a plurality of optical single fibers 3 bundled together 2 and at least one sheath 4, 5 surrounding at least one segment of the outer periphery of the bundle, the at least one sheath 4, 5 being made of ceramic.

[0060] List of reference numerals

[0061] 1. Optical light guide

[0062] 2 bundles

[0063] 3 Single Fiber

[0064] 4 (First) Sheath

[0065] 5 (Second) Sheath

[0066] The first free end of the 6 bundles

[0067] 7. The second free end of the bundle

[0068] 8. Change of direction

[0069] 9. Cross-section

[0070] 10 End Region

[0071] 11 Central Area

[0072] 12-axis

[0073] 13. Remote

[0074] 14 Proximal

[0075] 15 bundles of outer periphery

[0076] 16 Light Sources

[0077] 17 Optical channels for image generation

[0078] 18 Endoscope tip

[0079] 19 First light guide

[0080] 20 Second light guide

[0081] 21 Guiding Channel

[0082] 22 Coverslip

[0083] 23 Light emission area

Claims

1. An optical light guide comprising a bundle of light guide single fibers and at least one sheath covering the outer periphery of at least one section of the bundle, characterized in that, The at least one sheath is made of ceramic and is arranged in a region of a tip of a scope, wherein the optical light guide changes direction in the region of the tip of the scope to align a front face of the optical light guide with an angled face of the tip of the scope.

2. The optical light guide of claim 1, wherein, The optical light guide comprises at least two sheaths each covering a segment of an outer periphery of the bundle.

3. The optical light guide of claim 2, wherein, The sheaths are arranged at each of two ends of the bundle, wherein one of the two ends is arranged at the tip of the scope.

4. The optical light guide of claim 1, wherein, The at least one sheath has at least two or more changes in direction.

5. The optical light guide of claim 1, wherein, The at least one sheath comprises a cross section that varies in shape along at least a portion of its course.

6. The optical light guide of claim 5, wherein the cross section of varying shape has the same cross sectional area.

7. The optical light guide of claim 1, wherein, At least one gap enclosed by the at least one sheath between the single fibers is at least partially filled with adhesive.

8. The optical light guide of claim 7, wherein the adhesive comprises a chemically hardenable adhesive.

9. The optical light guide of claim 1, wherein, The cross section of the sheath narrows along its course.

10. The optical light guide of claim 1, wherein, An end region of the sheath comprises a cross sectional area that is smaller than a region located at a distance from the end region.

11. The optical light guide of claim 1, wherein the angled face of the tip of the scope is not perpendicular to a longitudinal axis of a shaft of the scope.

12. The endoscope having the optical light guide according to claim 1, wherein, With the optical light guide, light can be guided between a distal end of a shaft and a proximal end of the shaft.

13. The scope of claim 12, wherein during use light is guided from the distal end of the shaft to the proximal end of the shaft.

14. The scope of claim 12, wherein during use light from a light source is guided from the proximal end of the shaft to the distal end of the shaft.

15. A scope comprising: a shaft; a tip at a distal end of the shaft; and an optical light guide configured to guide light between the distal end and a proximal end of the shaft, the optical light guide comprising a bundle of light guiding single fibers and a sheath covering an outer periphery of a segment of the bundle, characterized in that the sheath is made of ceramic and is arranged in a region of the tip of the scope, wherein the optical light guide changes direction in the region of the tip of the scope to align a front face of the optical light guide with an angled face of the tip of the scope.

16. The scope of claim 15, wherein the angled face of the tip of the scope is not perpendicular to a longitudinal axis of the shaft of the scope.

17. The scope of any of claims 15-16, further comprising: an additional optical light guide configured to guide light between the distal end and the proximal end of the shaft, the additional optical light guide comprising a bundle of light guiding single fibers and a sheath covering an outer periphery of a segment of the bundle, characterized in that the sheath is made of ceramic and is arranged in a region of the tip of the scope.

18. A method for manufacturing an optical light guide having a bundle of light guide single fibers and at least one sheath surrounding the outer periphery of at least one section of the bundle, characterized in that, The bundle of monofilaments is introduced into the sheath, which is made of a ceramic material and forms a non-linear channel configured for guiding the bundle to set the angle of the front face of the bundle for alignment with an angled face of a tip of an endoscope.

19. The method of claim 18, further comprising at least partially filling the gaps between the monofilaments enclosed by the at least one sheath with an adhesive.

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