Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B23/00—Telescopes, e.g. binoculars; Periscopes; Instruments for viewing the inside of hollow bodies; Viewfinders; Optical aiming or sighting devices
  • G02B23/24—Instruments or systems for viewing the inside of hollow bodies, e.g. fibrescopes
  • G02B23/2407—Optical details
  • G02B23/2415—Stereoscopic endoscopes
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
  • A61B1/00064—Constructional details of the endoscope body
  • A61B1/00071—Insertion part of the endoscope body
  • A61B1/0008—Insertion part of the endoscope body characterised by distal tip features
  • A61B1/00096—Optical elements
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
  • A61B1/00163—Optical arrangements
  • A61B1/00174—Optical arrangements characterised by the viewing angles
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
  • A61B1/00163—Optical arrangements
  • A61B1/00193—Optical arrangements adapted for stereoscopic vision
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
  • A61B1/04—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor combined with photographic or television appliances
  • A61B1/044—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor combined with photographic or television appliances for absorption imaging
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B23/00—Telescopes, e.g. binoculars; Periscopes; Instruments for viewing the inside of hollow bodies; Viewfinders; Optical aiming or sighting devices
  • G02B23/24—Instruments or systems for viewing the inside of hollow bodies, e.g. fibrescopes
  • G02B23/2407—Optical details
  • G02B23/2423—Optical details of the distal end
  • G02B23/243—Objectives for endoscopes
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B23/00—Telescopes, e.g. binoculars; Periscopes; Instruments for viewing the inside of hollow bodies; Viewfinders; Optical aiming or sighting devices
  • G02B23/24—Instruments or systems for viewing the inside of hollow bodies, e.g. fibrescopes
  • G02B23/2407—Optical details
  • G02B23/2446—Optical details of the image relay
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B23/00—Telescopes, e.g. binoculars; Periscopes; Instruments for viewing the inside of hollow bodies; Viewfinders; Optical aiming or sighting devices
  • G02B23/24—Instruments or systems for viewing the inside of hollow bodies, e.g. fibrescopes
  • G02B23/2407—Optical details
  • G02B23/2453—Optical details of the proximal end
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N13/00—Stereoscopic video systems; Multi-view video systems; Details thereof
  • H04N13/20—Image signal generators
  • H04N13/204—Image signal generators using stereoscopic image cameras
  • H04N13/243—Image signal generators using stereoscopic image cameras using three or more two-dimensional [2D] image sensors

Definitions

• the present invention relates to an optical system of a lateral view stereoscopic video endoscope comprising a sideways-looking distal optical assembly and a proximal optical assembly, wherein the distal optical assembly successively comprises an entrance lens, an optical deflector, and an exit lens formed as a hollow positive meniscus in a light incident direction encompassed on a common optical axis, wherein the distal optical assembly at least partially two similar, mutually parallel right and left Linsensystemkanäle each having its own optical axis, each having at least a first lens and an achromatic lens group in the light incident direction, and a corresponding stereo video endoscope with lateral viewing direction.
• CONFIRMATION COPY Radeaus looking endoscopes limited, so on endoscopes with a so-called 0 ° -View direction.
• US 5 689 365 A discloses a system of a sideways-looking stereoscopic endoscope having a distal and a proximal optical assembly.
• the distal optical assembly is located distally behind an inclined entrance window and includes a plano-convex entrance lens which rests on a prism deflection unit in which the inclined optical axis of the system is deflected in the direction of the longitudinal extension of the shaft of the endoscope.
• a positive raised meniscus lens is arranged as the exit lens of the distal optical assembly. Proximally, this is followed by the proximal optical assembly. While the distal optical assembly is rotatably connected to the cladding tube, the proximal optical assembly is rotatably mounted in the cladding tube to allow a change in the viewing direction.
• the proximal optical assembly comprises two Linsenkanalsyste- mees, namely each for the right image and the left image separately, in each of which a biconvex inlet lens and a designed as a doublet achromatic array are arranged.
• Two image sensors are non-rotatably connected to this rotatable proximal optical assembly and receive the separated left and right images.
• US 5,689,365 A also introduces various other optical systems which operate in a similar manner, including, for example, reverse lens sets used to convey the incident light into the handle of an endoscope and to the image sensors located there.
• a stereo base of less than 1.1 mm can be realized with an outer diameter of the endoscope shaft of more than 15 mm. This means that it is insufficiently suitable for endoscopic use because of its diameter and the achievable three-dimensional effect is not sufficiently large. Further, in the optical system, so-called 3D distortions are not sufficiently corrected.
• the present invention has for its object to provide an optical system of a stereo video endoscope with lateral viewing direction and a corresponding stereo video endoscope with such an optical system that provides the same or smaller size equal or larger stereo base, whereby also SD distortions should be corrected.
• an optical system of a lateral-viewing stereo video-endoscope comprising a side-facing distal optical assembly and a proximal optical assembly, wherein the distal optical assembly successively comprises an entrance lens, an optical deflection unit and a hollow one in a light incident direction Meniscus formed exit lens on a common optical axis, wherein the distal optical assembly at least partially has two similar, mutually parallel right and left lens system channels each having its own optical axis, each having at least a first lens and an achromatic lens group in the light incident direction, which is further developed in that the entrance lens is formed as a raised negative meniscus.
• the entrance lens is now not designed as a plano-convex lens but as a raised negative meniscus lens, which is also called a meniscus in the field of imaging optics becomes. It is thus a convex-concave lens, wherein the radius of curvature of the convex lens surface is equal to or greater than the radius of curvature of the concave lens surface.
• the convex surface is the left surface and the concave surface is the right surface of the entrance lens.
• the distal optical unit thus initially has a raised negative meniscus and a hollow positive meniscus at the outset. This combination ensures that 3D distortions are reduced or eliminated. This makes it possible to increase the stereo base with a constant or smaller size, since the stereo image is no longer limited by 3D distortions in its 3D effect.
• / R r of the radii of curvature of the convex surface (61 a) and the concave surface (61 b) of the entrance lens (61) is between 1.0 and 3.0.
• the abbreviations "I” and “r” stand here and throughout the application for "left” and “right” in the above-mentioned Convention of Theoretical Optics. However, this nomenclature is not to be confused with the left and right image channels of stereoscopy.
• / R r of the radii of curvature of the concave surface (63a) and the convex surface (63b) of the exit lens (63) is between 2.0 and 4.0.
• a ratio FL A / FL E of the focal lengths of the exit lens (63) and the entrance lens (63) is between -1.55 and -1.75.
• FL for "focal length” denotes the focal length.
• the entrance lens is rotatable together with the deflection unit with respect to the exit lens, wherein in particular a diaphragm is arranged in front of the exit lens.
• a diaphragm is arranged in front of the exit lens.
• the entrance lens, the deflection unit and the exit lens are rotatable together, wherein in particular a diaphragm is arranged after the exit lens. This alternative improves the stability of the focus position when the viewing direction is rotated.
• the exit lens is arranged to be movable in the axial direction in a preferred embodiment for setting a focus position.
• the axial direction is the direction of the longitudinal extension of the endoscope shaft.
• each lens system channel of the proximal optical unit has a plano-convex lens as the first lens and a triplet as the achromatic lens group.
• the lens system channels each having one or more optical reversing sets or arranged in front of or behind one or more common reversing optical sets or reversing sets, it is possible to separate the light bundles of the two lens system channels through the endoscope shaft to transmit proximally into the handle.
• each lens system channel can have its own reversing set or a series of reversal sets, or a common optical reversal set having an overall diameter of the individual lens components of the reversal set can be used which is large enough to simultaneously transmit the light beams of both lens system channels.
• This procedure has the advantage that, for example, the larger space available in the handle can be used for using larger image sensors and / or for further enlarging the stereo base, ie the distance of the viewing position for the left and right images from one another.
• the lens system channels lead to one or more image sensors which are or are rotationally fixed relative to the proximal optical assembly and / or to the lens system channels.
• the lens system channels in particular via their own or common optical reversing sets, lead to a common image sensor, wherein the Image sensor receives light from the two lens system channels simultaneously in separate areas of its photosensitive sensor surface.
• the Image sensor receives light from the two lens system channels simultaneously in separate areas of its photosensitive sensor surface.
• it is a large image sensor that has enough space for the non-overlapping areas illuminated by the left channel and the channel.
• the lens system channels lead, in particular via their own or common optical reversing sets, to a common image sensor, wherein an optical switching element is additionally included, in particular a rotating mirror, a switchable polarizer or a lenticular, by means of which the image sensor light from the two lens system channels in temporal Sequence receives alternately successively or simultaneously in spatially alternating sequence.
• an optical switching element is additionally included, in particular a rotating mirror, a switchable polarizer or a lenticular, by means of which the image sensor light from the two lens system channels in temporal Sequence receives alternately successively or simultaneously in spatially alternating sequence.
• a lenticular grid also referred to as a "lenticular lens” is an array of lenticular or triangular prisms in cross-section arranged in a striped or linear pattern distributed over a surface, which redirects the light so that successive rows of sensor cells of the image sensor alternate Receive light from the left lens system channel and right lens system channel.
• the object underlying the invention is also achieved by a stereo video endoscope with lateral viewing direction, comprising a previously described inventive optical system.
• Fig. 1 is a known stereo video endoscope with lateral
• FIG. 3 shows details of a further exemplary embodiment of an optical system according to the invention in a schematic representation
• FIG. 4 details of another optical according to the invention
• FIG. 1 shows a cross-sectional representation of a stereo video endoscope known from the prior art according to US Pat. No. 5,689,365.
• the stereo video endoscope 1 comprises an endoscope shaft 2 and a handle 3.
• an optical fiber bundle 13 for illuminating the surgical field distal to the endoscope shaft 2 is arranged, which ends in the handle 3 in an optical fiber connection 4.
• a distal optical assembly 14 Disposed distally behind an input window 14a in an inner cladding tube (not numbered) is a distal optical assembly 14 having a plano-concave entrance list 14b, a prism deflection unit 14c, and an exit lens 14d formed as a hollow positive meniscus.
• the entrance lens 14b, the deflection unit 14c and the exit lens 14d are non-rotatably connected to the shaft 2 and the cladding tube 12, respectively.
• a proximal optical assembly 15 is rotatably disposed within the inner cladding tube, wherein the axis of rotation is the central axis of symmetry of the endoscope shaft 2.
• the proximal optical assembly 15 is disposed in a rotatable support 16 and has two separate lens system channels for a right image and a left image of a stereoscopic image pair.
• the lens system channels each have a left to right in FIG. 1 Aperture 20, a biconvex input lens and an achromatic lens group formed as a doublet.
• An image sensor 18 connects to each of the lens system channels.
• the entire proximal optical assembly 15 is rotatably arranged in the shaft 2 by means of a coupling element 17, which is connected to the handle 3 and rotates the handle 3 with respect to the shaft 2.
• a coupling element 17 Through the center of the coupling element 17, a signal cable 19 is guided, which opens at the end of the handle 3 in an outer signal cable 7, which can lead, for example, to an external computer system.
• This optical system is affected by stronger 3D distortions that limit the usable stereo base.
• FIG. 2 shows an optical system 50 according to the invention, which has a distal optical assembly 60 according to the invention and a proximal optical assembly 70 according to the invention behind an entrance window 51 which corresponds to the entry window 14a from FIG.
• the distal optical assembly 60 comprises an entrance lens 61, which is formed as a raised negative meniscus, with a convex left surface 61 a and a concave right surface 61 b, the designations left and right in this context with respect to the usual definition in theoretical optics are selected, that light enters from the left and exits to the right.
• a deflection unit 62 in the form of a prism unit, with two partially mirrored or mirrored boundary surfaces 62b, 62c, with which the obliquely laterally entering light is deflected in the direction of the axis of the endoscope shaft. It is a partially mirrored prism 62a and a further prism not shown in detail. Behind the deflection unit 62, an exit lens 63 is disposed behind a shutter 64 formed as a hollow positive meniscus lens, ie, the left lens surface is concave, the right convex, and the radius of curvature of the concave lens surface 63a is larger than the radius of curvature of the convex lens surface 63b.
• the light After a short distance, the light reaches the first lenses 71a, 72a of the left and right lens system channels 71 and 72 of the proximal optical assembly 70, which are formed as rod lenses.
• the rod lenses 71 a, 72 a each close achromath th lens groups 71 b and 72 b, which are formed as triplets, of which at least one lens has a high Abbe number. This is followed by the image sensors 71 c, 72 c.
• Fig. 2 typical beam paths of central and peripheral light beams are drawn.
• the three beams reaching the image sensor 71 correspond to the fifth, third and uppermost bundles passing through the entrance lens 51 viewed from above, while the bundles reaching the image sensor 72c correspond to the sixth, fourth and second uppermost bundles.
• the ratios of the radii of curvature of the entrance and exit surfaces of the entrance lens and the exit lens of the distal optical assembly 60 correspond to the particularly preferred ranges according to the invention.
• / R r of the entrance lens is 2.03
• / R r of the exit lens is 2.63
• the ratio of the focal lengths of entrance lens to exit lens is -1.7.
• the radii of curvature, optical path lengths, refractive indices and Abbe numbers of the elements of the optical system shown in Fig. 2 are shown in the following table:
• the radii and distances are in millimeters, the refractive index n and the Abbe number v are unitless.
• a radius labeled "INF" indicates a plane boundary, and lines that contain no Abbe number v for the refractive index n indicate air
• a lens, such as the entrance lens is comprised of two rows of the table Line, for example the one with the radius indication 5, 101, first designates the left, in this case convex lens surface
• R 2.51 1 Since an air gap is located on the right lens surface closes, here is the distance of 1, 03 indicated as the thickness of the air gap, where n and v remain open due to the material air.
• the last three lines of the table indicate that the image sensor is each protected by a double layer of glasses.
• a side-looking stereo video endoscope having a thickness of 10 mm and a stereo base of 1.3 mm can be realized.
• FIG. 3 shows a detailed view of a further optical system according to the invention, wherein the deflecting unit 62 and the exit lens 63 are only partially shown by the distal optical assembly 60.
• a series of reversal sets 71 c, 72 c is shown schematically, with which the respective left or right image is forwarded to the proximal.
• the reversal sets 71c, 72c shown in FIG. 3 are shown symbolically. Actual inverse sets are usually formed as rod lens systems with two or more lenses per reversing set. It can be one or more reversals.
• a common reversing set group or arrangement the diameter of which corresponds to the overall diameter of the proximal assembly 70, may be used instead of individual reversal sets 71c, 72c of the lens system channels 71 and 72.
• the two lens system channels 71, 72 are completed in Fig. 3 by means of a respective scattering lens, the respective light beam to two separate areas 71 e, 72 e of a common image sensor 75 steer.
• FIG. 4 shows an alternative example of the proximal end of the lens system channels 71, 72, wherein the last lenses (without reference symbols) of the lens system channels 71 and 72 direct the respective light beams onto the same area of the common image sensor 75.
• a lenticular array is arranged in the form of strip-shaped prisms, which ensure that light from the lens system channel 71 and from the lens system channel 72 is directed onto alternating or alternating lines of the image sensor 75.
• the even-numbered lines include the image of the right channel and the odd-numbered lines the image of the left channel. Another division is possible, for example, with low spatial frequency.
• Fig. 5 shows an alternative embodiment in which the images or light beams of the left and right lens system channels 71 and 72 are in turn projected onto a common surface on the image sensor 75.
• the system in Fig. 5 is further developed in that behind the respective output of the left and right image channels or lens system channels 71 and 72 respectively differently polarized polarization filters 71 f, 72 f are arranged and in the path between the lens system channels 71 and 72 and the image sensor 75 a switchable Polarizer 77 is arranged, which alternately passes through the polarized light of the left channel and the right channel. This approach allows for high optical quality and a large stereo base.

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• Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Surgery (AREA)
• Optics & Photonics (AREA)
• General Health & Medical Sciences (AREA)
• Radiology & Medical Imaging (AREA)
• Engineering & Computer Science (AREA)
• Medical Informatics (AREA)
• Veterinary Medicine (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Molecular Biology (AREA)
• Animal Behavior & Ethology (AREA)
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• Pathology (AREA)
• Astronomy & Astrophysics (AREA)
• General Physics & Mathematics (AREA)
• Multimedia (AREA)
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• Endoscopes (AREA)
• Instruments For Viewing The Inside Of Hollow Bodies (AREA)
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• 2013
  • 2013-08-06 DE DE102013215422.4A patent/DE102013215422B4/de active Active
• 2014
  • 2014-07-08 WO PCT/EP2014/001876 patent/WO2015018473A1/de not_active Ceased
  • 2014-07-08 CN CN201480044750.7A patent/CN105474066B/zh active Active
  • 2014-07-08 JP JP2016532245A patent/JP6482553B2/ja active Active
• 2016
  • 2016-02-05 US US15/016,791 patent/US10088665B2/en active Active

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