VIDEO ENDOSCOPE

Description

[0001] The invention relates to a video endoscope with an outer sheath tube, a fiber tube for an inner sheath tube and with an inner sheath tube for an imaging unit.

[0002] When assembling endoscopes, inner tubes are often inserted into an outer sheath tube. These inner tubes are designed to fit relatively tightly to prevent misalignment. In video endoscopes in particular, the video unit, also known as the R-unit, is inserted into an outer sheath tube. The video unit comprises an inner tube or inner sheath tube into which optical elements and a video camera or at least a light-sensitive chip, such as a CCD chip, are integrated. To enable precise alignment or precise fixation of the inner tube to the optical axis, the fit to the outer sheath tube or the tube into which the inner tube or inner sheath tube for the imaging unit is inserted is relatively tight.

[0003] In particular, in video endoscopes, the imaging unit, or R-unit, is inserted into the outer sheath or fiber tube and secured proximally. A shrink tube is pulled over the sheath for the R-unit. The shrink tube serves to prevent rattling of the inner sheath and also provides electrical insulation. A heating foil is applied around the circumference of the fiber tube for the inner sheath.

[0004] DE 20 2005 019 684 U1 discloses an endoscope-like device in which a heating system is integrated into a tube, which supplies heat to the opening of the tube. Furthermore, an electrical heating element is incorporated into the tube.

[0005] Furthermore, US 2010 / 0268027 A1 discloses an endoscope, wherein a heating unit is provided within a holding element at the distal end of the endoscope. Furthermore, the heating unit comprises a heating element arranged at a distal viewing window.

[0006] Furthermore, DE 10 2008 031 924 A1 describes an endoscope with a resistance heater, wherein the heater is designed as a heating foil on the outer surface of the fiber tube.

[0007] The subsequently published document DE 10 2015 101 624 A1 discloses a video endoscope, wherein a cavity is provided in the area between a lower edge of a prism assembly and a wall of a fiber tube. A heating element, for example, can be arranged in this cavity.

[0008] In addition, JP 2014-131531 A describes an anti-fogging system for an endoscope with a heater.

[0009] Based on this prior art, the object of the invention is to enable cost-effective assembly of video endoscopes, whereby it should be possible to provide more installation space for other components of the endoscope if necessary.

[0010] This object is achieved by a video endoscope with an outer cladding tube, wherein a fiber tube for an inner cladding tube is accommodated in the outer cladding tube, wherein an inner cladding tube for an imaging unit is accommodated in the fiber tube and wherein a heating foil enclosing the inner cladding tube is provided between the fiber tube and the inner cladding tube.

[0011] The video endoscope according to the invention comprises an outer cladding tube and an inner cladding tube for an imaging unit. Furthermore, a fiber tube is provided for the inner cladding tube, with the outer cladding tube accommodating the fiber tube and the inner cladding tube accommodating the fiber tube. Furthermore, a heating foil enclosing the inner cladding tube is arranged between the fiber tube accommodating the inner cladding tube and the inner cladding tube.

[0012] The invention is based on the idea that, in the video endoscope according to the invention, a heating foil is applied to the inner cladding tube for the imaging unit or the R-unit instead of the previous shrink tubing. The heating foil is positioned between the inner cladding tube and the fiber tube surrounding the inner cladding tube. The heating foil is not only used for heating but also acts as a rattle protection for the inner cladding tube. Furthermore, the heating foil can also be used for electrical insulation. This depends on the geometry of the installation space in the endoscope shaft or in the outer cladding tube.

[0013] By placing the heating foil between the fiber tube and the inner sheath tube (instead of the previous shrink tube), the shrink tube is no longer required for the video endoscope assembly, eliminating one component (the shrink tube). Furthermore, this simplifies the assembly of the endoscope, as an assembly step is eliminated. Furthermore, by eliminating the shrink tube, the diameter is reduced, creating more space for optical fibers or the optics, for example, or allowing the use of more stable tubes. Furthermore, the diameter reduction makes it possible to provide video endoscopes with a smaller endoscope shaft diameter.

[0014] For example, the heating foil is used to heat a distal window of an endoscope to prevent fogging. The heating foil provides electrical resistance heating, which is preferably located near the window in the endoscope shaft. The contact of the heating foil with the fiber tube, which is usually made of metal, ensures good heat transfer through the fiber tube to the window, which is preferably soldered into the fiber tube, ensuring good thermal contact.

[0015] For this purpose, a further development provides that the inner cladding tube has a tube section, wherein the tube section of the inner cladding tube is surrounded by the heating foil in the circumferential direction. The heating foil thus encloses the tube section of the inner cladding tube.

[0016] Furthermore, the video endoscope is characterized in a further development by the fact that the heating foil is designed as a tubular or heating foil tube.

[0017] Preferably, the heating foil is in immediate or direct contact with the fiber tube and with the inner cladding tube.

[0018] In particular, the heating foil is made of plastic, especially polyimide. Heating foils made of Kapton ® are particularly suitable for this purpose.

[0019] In addition, in one embodiment of the video endoscope, it is further provided that an optical fiber bundle is accommodated in the outer sheath tube in addition to the fiber tube for the inner sheath tube.

[0020] In a further development, the video endoscope preferably provides at least one temperature sensor for detecting the temperature of the heating foil, wherein the heating foil in particular has the at least one temperature sensor. The temperature sensor detects or determines the temperature of the heating foil in the endoscope shaft, making it possible to set a predetermined temperature by means of a control device or control loop depending on the detected heating foil temperature.

[0021] For this purpose, one embodiment of the video endoscope provides a temperature control device for controlling the temperature of the heating foil. The temperature control device is preferably connected to a temperature sensor of the heating foil or for the heating foil in order to receive a measured actual temperature from this temperature sensor, so that a predetermined temperature of the heating foil is set or regulated by means of an actual-set value comparison in the temperature control device connected to the heating foil.

[0022] Preferably, the heating foil has a positive temperature coefficient of electrical resistance.

[0023] Further features of the invention will become apparent from the description of embodiments of the invention together with the claims and the accompanying drawings. Embodiments of the invention may fulfill individual features or a combination of several features.

[0024] The invention is described below, without limiting the general inventive concept, using exemplary embodiments with reference to the drawings, whereby express reference is made to the drawings for all details of the invention not explained in more detail in the text. They show: Fig. 1 schematically shows a cross-section through a distal end region of an endoscope shaft according to the prior art, and Fig. 2 schematically shows a cross-section through a distal end region of an endoscope shaft according to the invention. Fig. 3 schematically shows a cross-section through a distal end region of an endoscope shaft according to the invention with a temperature control.

[0025] In the drawings, identical or similar elements and / or parts are provided with the same reference numbers, so that a repeated presentation is omitted.

[0026] Fig. 1shows schematically a cross section through an endoscope shaft 10 of a schematically designated video endoscope E in detail, wherein in Fig. 1 the section shows a distal end region of the endoscope shaft 10.

[0027] The endoscope shaft 10 has an outer sheath tube 1, which surrounds a fiber tube 4 wrapped by a heating foil 3. The fiber tube 4 is arranged eccentrically in the outer sheath tube 1. The space between the fiber tube 4 or the outer heating foil 3 and the outer sheath tube 1 is filled with optical fibers 2, which terminate distally in the end face of the video endoscope E.

[0028] The fiber tube 4 encloses an inner cladding tube 6 arranged inside the fiber tube 4 for an imaging unit (not shown here) for the video endoscope E. The imaging unit can be designed as a so-called R-unit, for example with a CCD chip.

[0029] A shrink tube 5 is arranged between the fiber tube 4 and the inner cladding tube 6, which encloses the inner cladding tube 6.

[0030] In order to prevent fogging of a distal window (not shown here) of the video endoscope E, the fiber tube 4 is surrounded by the heating foil 3, which is wrapped around the outer surface of the fiber tube 4.

[0031] The heating foil 3 is connected via a cable (not shown here) in order to apply current to a heating resistor in the heating foil 3, whereby the heating foil 3 and the fiber tube 4 surrounded by the heating foil 3 are heated, so that a front window of the video endoscope E is heated.

[0032] In Fig. 2 is a schematic cross-sectional view of a section of an endoscope shaft 10 of the video endoscope E according to the invention. The distal end region of the endoscope shaft 10 is shown in Fig. 2shown schematically. A fiber tube 4 is arranged inside the outer cladding tube 1, with the elongated inner cladding tube 6 being arranged inside the fiber tube 4. A heating foil 3 is arranged between the fiber tube 4 and the inner cladding tube 6 and is in direct contact with the fiber tube 4 and the inner cladding tube 6. The heating foil 7 is preferably made of Kapton®. In addition, corresponding connection means for the resistance heating of the heating foil 7 are also provided in order to heat the fiber tube 4.

[0033] In Fig. 3 A cross-section through an endoscope shaft is shown schematically, whereby compared to the embodiment in Fig. 2Temperature control is possible for the heating foil 7. The heating foil 7 has a temperature sensor 8, by means of which the temperature of the heating foil 7 is detected. When current is applied to the heating foil 7, it is heated, so that the temperature of the heating foil 7 determined by the temperature sensor 8 is transmitted to a temperature control device 9. After an actual-setpoint comparison in the temperature control device 9, the strength of the electric current for the heating foil 7 is regulated accordingly, so that a preferred temperature is set and kept constant in the heating foil.

[0034] All mentioned features, including those that can be inferred from the drawings alone, as well as individual features disclosed in combination with other features, are considered essential to the invention, both individually and in combination. Embodiments according to the invention may be fulfilled by individual features or a combination of several features. Within the scope of the invention, features marked "in particular" or "preferably" are to be understood as optional features. List of reference symbols

[0035] 1Outer sheath tube 2Optical fibers 3Heating foil 4Fiber tube 5Shrink tubing 6Inner sheath tube 7Heating foil 8Temperature sensor 9Temperature control device 10Endoscope shaft EVideo endoscope

Claims

1. A video endoscope (E) with an outer casing tube (1), wherein a fiber tube (4) for an inner casing tube (6) is accommodated in the outer casing tube (1), wherein an inner casing tube (6) for an image-forming unit is accommodated in the fiber tube (4) and wherein a heating film (7) surrounding the inner casing tube (6) is provided between the fiber tube (4) and the inner casing tube (6).

2. The video endoscope (E) according to claim 1, characterized in that the inner casing tube (6) has a tube section, wherein the tube section of the inner casing tube (6) is enclosed by the heating film (7) in the circumferential direction.

3. The video endoscope (E) according to claim 1 or 2, characterized in that the heating film (7) is designed sleeve-shaped or as a heating film sleeve.

4. The video endoscope (E) according to one of claims 1 to 3, characterized in that the heating film (7) is in immediate or direct contact with the fiber tube (4) and with the inner casing tube (6).

5. The video endoscope (E) according to one of claims 1 to 4, characterized in that the heating film (7) is produced from plastic, in particular from polyimide.

6. The video endoscope (E) according to one of claims 1 to 5, characterized in that an optical fiber bundle (2) is accommodated in the outer casing tube (1) next to the fiber tube (4) for the inner casing tube (6).

7. The video endoscope (E) according to one of claims 1 to 6, characterized in that at least one temperature sensor (8) for detecting the temperature of the heating film (7) is provided, wherein in particular the heating film (7) has the at least one temperature sensor (8).

8. The video endoscope (E) according to one of claims 1 to 7, characterized that a temperature control device (9) for controlling the temperature of the heating film (7) is provided.

9. The video endoscope (E) according to one of claims 1 to 8, characterized in that the heating film (7) has a positive temperature coefficient of the electrical resistance.