Optical Coherence Tomography Scanning System and Method
An optical coherence tomography scanning system traverses its respective scan pattern quickly, typically completing an entire two-dimensional frame faster than a conventional raster scanner completes one raster line segment. To traverse the scan pattern quickly, the system takes fewer A-scans per length of scan pattern than a conventional OCT scanner. To compensate for the sparsity of the sample points along the respective scan line segments, and for gaps between respective line segments of the trajectory, the system acquires and combines several partially overlapping frames for each study.
1 . A tomography system comprising:
a probe housing defining a window and configured to be translated along a path proximate an anatomical item in a live patient, the anatomical item having a surface;
an optical coherence tomography system comprising a sample arm and an optical detector, wherein a portion of the sample arm extends outside the probe housing, in free space, via the window;
a moveable mirror system disposed within the probe housing and configured to redirect the sample arm;
a motor disposed within the probe housing and coupled to the mirror system; and
a controller configured to automatically:
drive the motor to repeatedly alter orientation of the mirror system about two different axes to thereby repeatedly scan the surface of the anatomic item with light of the sample arm along a trajectory according to a deterministic smooth two-dimensional scan pattern, such that:
each traversal of the scan pattern defines a respective two-dimensional scan area outer boundary on a respective portion of the surface of the anatomic item;
each traversal of the scan pattern defines a plurality of gaps between respective line segments of the trajectory, wherein the gaps are unilluminated by the light during the traversal; and
successive traversals of the scan pattern, in which respective scans are performed from different locations along the path, and each such scan has a respective scan area outer boundary that partially overlaps a scan area outer boundary of at least one other such scan, illuminate respective portions of at least some of the gaps defined by at least one other such traversal of the scan pattern;
for each traversal, receive pixel image data from the optical detector, about the respective portion of the surface of the anatomic item, wherein the pixel image data of each traversal contains a first number of pixels; and
for a plurality of successive traversals, in which respective scans are performed from different locations along the path, and each such scan has a respective scan area outer boundary that partially overlaps a scan area outer boundary of at least one other such scan, stitch together the pixel image data of the plurality of successive traversals to thereby generate a stitched surface image having a number of pixels greater than the first number of pixels.