Surgery – Endoscope – Having imaging and illumination means
Reexamination Certificate
1999-02-12
2001-06-19
Leubecker, John P. (Department: 3739)
Surgery
Endoscope
Having imaging and illumination means
C600S130000, C600S169000, C600S171000, C600S177000, C600S178000
Reexamination Certificate
active
06248060
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a rigid endoscope, comprising a jacket tube having an optical system and a first glass fiber bundle shining parallel to the image axis of the optical system, for illuminating an object to be examined, and a second optical illumination system also aimed at the object to be examined.
It is known in principle that a rigid optical system for endoscopy, hereinafter called a rigid endoscope, comprises an optical system used for imaging a light source for illuminating the object being examined. It is also known, for instance from European Patent No. 0 369 937 A1, that the light source is realized with a glass fiber bundle, or so-called optical wave guide, located parallel to the optical axis of the optical system. In the prior are, the light from an external light source is input into the glass fiber bundle at the proximal end (the side toward the user) via a further glass fiber bundle, the so-called optical fiber cable. Via the glass fiber bundle, the light is transmitted to the distal end of the endoscope (the side toward the object being examined). The light source thus shines from the direction of the observer onto the object.
However, such endoscopes have the disadvantage that surgical instruments located in front of the optical system of the endoscope during the operation generally cast no shadow on the organs being examined. This is because articles introduced between the observer and the object being observed, hereinafter called the image background, are known not to cast shadows on the image background, if the light exit axis of the light source and the optical image axis of the observer coincide. Because of the endoscopic two-dimensional image, the surgeon already lacks depth information about the three-dimensional space being examined, and thus the three-dimensional impression of the region of the operation is restricted. In the endoscopes mentioned, this three-dimensional impression is restricted still further by the unnatural lighting or the absence of the shadow.
In angled endoscopes, such as a laparoscope with a 30° viewing direction, there is a slight asymmetry, because of constructional requirements, between the light exit axis of the light source and the optical image axis of the observer. However, this asymmetry is kept as slight as possible, so that the angle between the light exit axis of the light source and the optical image axis of the observer tends toward zero, and shadow formation, which would increase the plasticity of image reproduction, is negligibly slight.
From German Patent 29 42 982 C2, an endoscope is known in which two light sources are provided for illuminating the near and far region in front of the optical system of the endoscope. Both light sources are embodied in the form of optical wave guides, whose free ends crosswise to the longitudinal direction of the endoscope are disposed immediately next to the distal end of the optical system of the endoscope. The light exits of the first light source extends parallel to the image axis of the optical system of the endoscope and thus to the viewing direction of the observer. To exclude the influence of parallax in the illumination of the near region by the first light source, the light exit axis of the second light source is inclined relative to the image axis of the optical system of the endoscope; the light exit axis of the second light source and the image axis of the optical system of the endoscope intersect, in the viewing direction of the user, in front of the optical system of the endoscope. The far region in front of the optical system of the endoscope is illuminated by the first light source that shines parallel to the image axis of the optical system of the endoscope, and the near region in front of the optical system of the endoscope is illuminated by the second light source, which shines in inclined fashion relative to the image axis of the optical system of the endoscope. However, like the endoscopes already discussed above, this endoscope, because of the only slight spacing between the distal end of the optical system of the endoscope and the free ends of the first and second optical wave guides, has negligibly slight shadow formation.
SUMMARY OF THE INVENTION
It is therefore the object of the invention to furnish an endoscope in which the vividness of image impression, for three-dimensional objects, such as surgical instruments, observed through the optical system, is increased.
The invention encompasses the teaching that increasing the vividness of image impression with three-dimensional objects is attainable if the light exit direction at the light exit of the second optical illumination system is offset laterally, relative to the viewing direction at the distal end of the optical system, that is, along the image axis of the optical system, by an amount such that for points on a three-dimensional object being examined, a parallax that has a value other than zero results with respect to the light exit of the second optical illumination system and of the distal end of the optical system. Preferably, the optical illumination system is also a glass fiber bundle. Because of this parallax, the shadow cast onto the image background by the observed three-dimensional object because of the light exiting from the second optical illumination system and the projection of the observed onto the image background, which projection originates at the distal end of the optical system, do not coincide. The surgeon looking through the optical system consequently sees the shadow of the observed three-dimensional object on the image background, and as a result the vividness of image impression is increased in a simple way. This shadow formation makes three-dimensional orientation in the body cavity being endoscoped considerably easier for the physician.
A further advantage of the endoscope of the invention is that the light from the two glass fiber bundles is superimposed in the three-dimensional space being examined. With regard to the light exit from the first and the second glass fiber bundle, there is again a parallax other than zero, and because of this an uneven distribution of light in the space being observed is attained, which in turn makes the topographical contrast on the object being examined and in the image background greater, thus advantageously also making them appear more vivid to the surgeon. The space being observed is also illuminated more diffusely or uniformly.
The light exit from the second glass fiber bundle can be disposed at a suitable distance perpendicular to the longitudinal axis of the endoscope, next to the distal end of the optical system. Because the diameter of an endoscope should be kept slight, the resultant parallax and the attendant shadow formation are relatively limited however. The light exit of the second glass fiber bundle is therefore preferably recessed by a distance (d) from the distal end of the optical system. As a result, even with a slight endoscope diameter, a relatively great parallax and thus an especially vivid image impression are attainable. The distance (d) is preferably approximately 5 to 50 mm.
In advantageous embodiments of the invention, the glass fibers of the first and/or second glass fiber bundle are distributed over an angular region coaxially about the optical system. As a result, particularly if the second glass fiber bundle is recessed, shading of a considerable portion of the space being observed by the distal end of the optical system or of the jacket tube is avoided, and thus an especially favorable illumination of the space being observed is attained. Preferably, the glass fibers of the first and/or second glass fiber bundle has a crescent-shaped cross section, because this produces an especially homogeneous distribution of the light exiting from the respective glass fiber bundle.
In especially favorable refinements of the invention, the light exit direction of the second glass fiber bundle and/or the viewing direction of the optical system is oriented in inclined fashion to t
Buess Gerhard Fritz
Flemming Ernst
Kunert Wolfgang Juergen
Naujoks Edward
Schurr Marc Oliver
Kinberg Robert
Leubecker John P.
MGB Endoskopische Geraete GmbH Berlin
Spencer George H.
Venable
LandOfFree
Rigid endoscope with second illumination system laterally... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Rigid endoscope with second illumination system laterally..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rigid endoscope with second illumination system laterally... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2500042