Oblique tip endoscope with zero degree field angle

Abstract

Systems, apparatuses, and methods are discussed herein for an endoscope. The endoscope has a distal tip with an oblique portion and a flat portion, the oblique portion defines a plane that forms an angle between and including 20 and 40 degrees to a central axis of the endoscope. A related sheath may have similar features at the distal tip.

1 . (canceled) 
     
     
         2 . A method of assembling an endoscope, comprising:
 obtaining an outer tube defining a first central axis, a first proximal end, and a first distal tip, and including a first portion at the first distal tip defining a first plane that forms an angle of between and including 20 and 40 degrees to the first central axis, and a second portion at the first distal tip defining a second plane perpendicular to the first central axis;   obtaining an inner tube defining a second central axis, a second proximal end, and a second distal tip, and including a first portion at the second distal tip defining a third plane that forms an angle of between and including 20 and 40 degrees to the second central axis and a second portion at the second distal tip defining a fourth plane perpendicular to the second central axis;   inserting the inner tube into the outer tube until the first and third planes are coplanar and two channels are defined within the outer tube, the first channel defined within the inner tube and the second channel defined between the inner tube and an inner surface of the outer tube;   inserting a visualization conduit into the second channel; and   optically exposing the visualization conduit at the first distal end to define a viewing angle parallel to the first central axis.   
     
     
         3 . The method of  claim 2 , wherein the first plane forms an angle between and including 30 and 34 degrees. 
     
     
         4 . The method of  claim 3 , wherein the first plane forms an angle of about 32 degrees. 
     
     
         5 . The method of  claim 2 , further comprising:
 attaching the inner tube to the outer tube at the first distal and second distal tips; and   attaching the inner tube to the outer tube at the first and second proximal ends.   
     
     
         6 . The method of  claim 5 , wherein at least one of the attaching steps includes soldering. 
     
     
         7 . The method of  claim 2 , further comprising:
 inserting a light fiber bundle into the second channel with the visualization conduit; and   optically exposing the light fiber bundle at the second plane.   
     
     
         8 . The method of  claim 2 , wherein the outer tube further includes:
 a first dimension measured perpendicularly to the first central axis and a second dimension measured perpendicularly to the first central axis and at a right angle to the first dimension, the second dimension equal to or smaller than the first dimension;   a first transition area on a first side of the first distal tip between the first portion and the second portion of the outer tube, the first transition area varying between the first portion and the second portion of the outer tube; and   a second transition area on a second side of the first distal tip opposite the first side, the second transition area varying between the first portion and the second portion of the outer tube.   
     
     
         9 . The method of  claim 8 , wherein, with respect to the outer tube:
 the first transition area defines a radius of curvature between and including 8% and 20% of the first dimension; and   the second transition area defines a radius of curvature between and including 8% and 20% of the first dimension.   
     
     
         10 . The method of  claim 2 , wherein the inner tube further includes:
 a third dimension measured perpendicularly to the second central axis, and a fourth dimension measured perpendicularly to the second central axis and at a right angle to the third dimension, the fourth dimension equal to or smaller than the third dimension;   a third transition area on a third side of the second distal tip between the first portion and the second portion of the inner tube, the third transition area varying between the first portion and the second portion of the inner tube; and   a fourth transition area on a second side of the second distal tip opposite the first side, the second transition area varying between the first portion and the second portion of the inner tube.   
     
     
         11 . the method according to  claim 10 , wherein, with respect to the inner tube:
 the third transition area defines a radius of curvature between and including 8% and 20% of the third dimension; and   the fourth transition area defines a radius of curvature between and including 8% and 20% of the fourth dimension.   
     
     
         12 . The method of  claim 2 ,
 wherein the outer tube further includes:
 a first dimension measured perpendicularly to the first central axis and a second dimension measured perpendicularly to the first central axis and at a right angle to the first dimension, the second dimension equal to or smaller than the first dimension; 
 a first transition area on a first side of the first distal tip between the first portion and the second portion of the outer tube, the first transition area varying between the first portion and the second portion of the outer tube; and 
 a second transition area on a second side of the first distal tip opposite the first side, the second transition area varying between the first portion and the second portion of the outer tube, 
   and wherein the inner tube further includes:
 a third dimension measured perpendicularly to the second central axis, and a fourth dimension measured perpendicularly to the second central axis and at a right angle to the third dimension, the fourth dimension equal to or smaller than the third dimension; 
 a third transition area on a third side of the second distal tip between the first portion and the second portion of the inner tube, the third transition area varying between the first portion and the second portion of the inner tube; and 
 a fourth transition area on a second side of the second distal tip opposite the first side, the second transition area varying between the first portion and the second portion of the inner tube. 
   
     
     
         13 . The method of  claim 12 ,
 wherein, with respect to the outer tube:
 the first transition area defines a radius of curvature between and including 8% and 20% of the first dimension; and 
 the second transition area defines a radius of curvature between and including 8% and 20% of the first dimension; and 
   wherein, with respect to the inner tube:
 the third transition area defines a radius of curvature between and including 8% and 20% of the third dimension; and 
 the fourth transition area defines a radius of curvature between and including 8% and 20% of the fourth dimension. 
   
     
     
         14 . The method of  claim 13 , wherein the inner tube further includes:
 a cross-sectional shape perpendicular to the second central axis, the cross-sectional shape defines a straight portion and a curved portion coupled on each end to the straight portion; and   a first height measured from an apex of the curved portion to the straight portion,   wherein the first height is greater half the first dimension of the outer tube, but smaller than an internal dimension of the outer tube measured parallel to the first dimension.   
     
     
         15 . The method of  claim 2 , wherein the outer tube is formed from a metallic material. 
     
     
         16 . The method of  claim 2 , wherein the inner tube is formed from a metallic material.