Apparatus and method for stereo viewing in variable direction-of-view endoscopy

An apparatus for use as an endoscope, comprising:

• a generally tubular member, a distal end portion, a proximal end portion, wherein said tubular member has a longitudinal axis;
• a viewing system, comprising a pivotable view vector originating from said distal end portion, wherein said pivotable view vector has a pivot axis that is not parallel to either said pivotable view vector or said longitudinal axis;
• a viewing window fixedly attached to said distal end portion, wherein said viewing window comprises a transparent viewing area wherein said transparent viewing area comprises all regions of said viewing window through which said viewing system may view, and wherein the external surface of said transparent viewing area is generally a complete or partial surface of revolution about said pivot axis and is substantially bilaterally symmetric about a symmetry plane, wherein said symmetry plane is generally parallel to both said pivot axis and said longitudinal axis near said distal end portion;
• a means for controllably rotating said distal end portion about said longitudinal axis;
• and
• a means for controllably rotating said pivotable view vector about said pivot axis.

A process for using an endoscope comprising a generally tubular member having a distal end portion, a proximal end portion, and a longitudinal axis, and a viewing system, wherein said viewing system comprises a pivotable view vector originating horn said distal end portion, said pivotable view vector having a pivot axis that is generally perpendicular to both said pivotable view vector and said longitudinal axis, wherein said view vector can be rotated to either side of a symmetry plane, said symmetry plane being generally parallel to said longitudinal axis near said distal end portion and generally parallel to said pivot axis, and wherein said endoscope has an initial configuration comprised of an initial distal end orientation and an initial view vector orientation, comprising the steps of:

• rotating said distal end portion about said longitudinal axis from said initial distal end orientation approximately 180 degrees to a final distal end orientation;
• and
• adjusting said view vector to a final view vector orientation symmetric across said symmetry plane from said initial view vector orientation;
• whereby the viewing direction of said initial configuration is substantially the same as the viewing direction of a final configuration comprising said final distal end orientation and said final view vector orientation.