Endoscope and related system

Abstract

An endoscope is described in which the diameter of the image relay assembly is less than that of the objective lens assembly. An endoscope sheath is also described for sheathing the endoscope and housing or directing optical fibers for use in illuminating the endoscope view of view. An endoscope-sheath system is further described comprising the combination of the endoscope and the endoscope sheath in eccentric alignment to reduce fluid flow impedance between the two.

1 . An endoscope-sheath system comprising:
 an endoscope having a distal end, the distal end having an outer diameter and housing optical elements and image transmission means;   a sheath having a distal end enclosing at least a portion of the endoscope distal end, the sheath having an inner diameter and a tip at the sheath distal end, the tip housing illumination elements, the endoscope removably insertable within the sheath; and   a separator disposed between the outer diameter and the inner diameter creating an eccentric alignment of the endoscope with respect to the sheath.   
     
     
         2 . The endoscope-sheath system of  claim 1  wherein the separator is integral to the inner diameter of the sheath. 
     
     
         3 . The endoscope-sheath system of  claim 2  wherein the separator comprises an indentation in the sheath. 
     
     
         4 . The endoscope-sheath system of  claim 1  wherein the separator is integral to the outer diameter of the endoscope. 
     
     
         5 . The endoscope-sheath system of  claim 4  wherein the separator is attached to the outer diameter of the endoscope. 
     
     
         6 . The endoscope-sheath system of  claim 1  wherein the separator creates one or more points of tangency between the endoscope and sheath substantially radially opposite the separator. 
     
     
         7 . The endoscope-sheath system of  claim 6  wherein the separator creates at the sheath distal end a fluid communication channel having a maximum width at a location substantially radially opposite the one or more points of tangency. 
     
     
         8 . An endoscope sheath comprising:
 a body portion;   a tip portion having a distal end, a distal opening at the distal end, an intermediate sub-portion, and a proximal end, and affixed to or integral with the body portion at the proximal end, the tip portion comprising inner and outer cylinders aligned eccentrically by a separator and forming one or more angular gaps in between the inner and outer cylinders;   a plurality of optical fibers extending lengthwise through the one or more angular gaps from the distal end of the tip portion to one or more illumination ports in the to intermediate sub-portion; and   one or more fluid ingress ports in the intermediate sub-portion located distally in relation to the one or more illumination ports.   
     
     
         9 . The endoscope sheath of  claim 8  wherein the inner and outer cylinders contact one another at one or more points of tangency. 
     
     
         10 . The endoscope sheath of  claim 9  wherein the one or more annular gaps have a maximum width at a location substantially radially opposite the one or more points of tangency. 
     
     
         11 . The endoscope sheath of  claim 8  wherein the separator is integral to the inner cylinder. 
     
     
         12 . The endoscope sheath of  claim 8  wherein the separator is integral to the outer cylinder. 
     
     
         13 . The endoscope sheath of  claim 8  wherein the separator comprises an indentation in a cylinder wall. 
     
     
         14 . The endoscope sheath of  claim 8  wherein the distal end has an end form that angles the distal opening toward a desired viewing field. 
     
     
         15 . The endoscope sheath of  claim 14  wherein the end form also angles the one or more angular gaps between the inner and outer cylinders at the distal opening towards the desired viewing field. 
     
     
         16 . The endoscope sheath of  claim 15  wherein the plurality of optical fibers have polished ends flush with and terminating at the distal opening. 
     
     
         17 . The endoscope sheath of  claim 16  wherein the one or more angular gaps are epoxy filled at the distal opening. 
     
     
         18 . The endoscope sheath of  claim 8  further comprising one or more fluid egress ports in the intermediate sub-portion of the tip portion. 
     
     
         19 . The endoscope sheath of  claim 18  wherein the one or more fluid egress ports are located at one or more planes of tangency between the inner and outer cylinders. 
     
     
         20 . The endoscope sheath of  claim 19  wherein the one or more fluid egress ports are located near the distal end of the tip portion. 
     
     
         21 . The endoscope sheath of  claim 8  wherein the inner and outer cylinders are each circular. 
     
     
         22 . The endoscope sheath of  claim 8  wherein the proximal end of the tip portion extends into a recess in the body portion. 
     
     
         23 . The endoscope sheath of  claim 22  wherein the body portion has a proximal opening that extends to the proximal end of the tip portion. 
     
     
         24 . The endoscope sheath of  claim 8  wherein one or more fluid ingress ports are openings in both cylinders. 
     
     
         25 . The endoscope sheath of  claim 24  further comprising an interface to a fluid communication component. 
     
     
         26 . The endoscope sheath of  claim 25  wherein the interface is a rotatable stopcock collar. 
     
     
         27 . The endoscope sheath of  claim 22  wherein the one or more illumination ports extend from a recess in the body portion to an exterior surface of the body portion. 
     
     
         28 . The endoscope sheath of  claim 8  wherein the one or more illumination ports is an opening in the outer cylinder allowing optical coupling between light from an illumination component and ends of one or more of the optical fibers. 
     
     
         29 . The endoscope sheath of  claim 28  wherein the one or more illumination ports further comprise an opening extending from a recess in the body portion to an exterior surface of the body portion. 
     
     
         30 . An endoscope-sheath system comprising:
 an endoscope comprising: (1) an intermediate portion having a distal end and a proximal end; (2) one or more optical elements forming an objective lens assembly having a first diameter, the objective lens assembly disposed at or within the distal end; and (3) one or more optical elements forming an image relay assembly having a second diameter less than the first diameter, the image relay assembly disposed at or within the intermediate portion and situated along an optical path extending from the objective lens assembly;   an endoscope sheath sheathing at least a portion of the endoscope comprising: (1) a distal end, an intermediate portion, and a proximal end, (2) inner and outer cylinders aligned eccentrically by a separator to contact one another at one or more points of tangency, thus forming one or more angular gaps in between the inner and outer cylinders; and (3) a plurality of optical fibers extending lengthwise through the one or more angular gaps from the distal end through at least a part of the intermediate portion; and   a body affixed to or integral with the proximal ends of the endoscope and endoscope sheath.   
     
     
         31 . The endoscope sheath of  claim 30  wherein the one or more annular gaps have a maximum width at a location substantially radially opposite the one or more points of tangency. 
     
     
         32 . The endoscope sheath of  claim 30  wherein the separator is integral to one of the inner and outer cylinders. 
     
     
         33 . The endoscope sheath of  claim 30  wherein the separator comprises an indentation in a cylinder wall. 
     
     
         34 . The system of  claim 30  wherein the endoscope distal end has a distal window through which light reflected from an object in the field of the view of the endoscope enters the endoscope. 
     
     
         35 . The system of  claim 34  wherein the endoscope distal window is situated within or optically coupled to the sheath distal window. 
     
     
         36 . The system of  claim 35  wherein the sheath distal end has an end form that angles the distal opening towards a desired viewing field. 
     
     
         37 . The system of  claim 36  wherein the end form also angles the one or more angular gaps between the inner and outer cylinders at the distal opening towards the desired viewing field.