US 12,295,660 B2
Multi-view corneal topographer
Peter Zieger, Berlin (DE); Martin Gründig, Rangsdorf (DE); Daniil Nekrassov, Berlin (DE); and Horia Grecu, Berlin (DE)
Assigned to ALCON INC., Fribourg (CH)
Filed by Alcon Inc., Fribourg (CH)
Filed on Feb. 1, 2022, as Appl. No. 17/649,560.
Claims priority of provisional application 63/146,837, filed on Feb. 8, 2021.
Prior Publication US 2022/0248951 A1, Aug. 11, 2022
Int. Cl. A61B 3/107 (2006.01); A61B 3/00 (2006.01); A61B 3/14 (2006.01); G06T 7/64 (2017.01); G06T 15/06 (2011.01)
CPC A61B 3/107 (2013.01) [A61B 3/0008 (2013.01); A61B 3/14 (2013.01); G06T 7/64 (2017.01); G06T 15/06 (2013.01); G06T 2207/30041 (2013.01)] 18 Claims
OG exemplary drawing
 
1. An ophthalmic system for generating a topography of an anterior corneal surface of an eye, the system comprising:
an illuminator configured to illuminate the anterior corneal surface of the eye with a Placido pattern, the eye having an axis, the anterior corneal surface reflecting the Placido pattern;
a plurality of cameras, each camera configured to generate an image of the reflected Placido pattern to yield a plurality of images, at least one camera oriented off the axis of the eye; and
a computer configured to:
receive the plurality of images from the cameras;
for each image of the plurality of images, calculate a curvature value for each data point of a plurality of data points of the image, each data point of the image corresponding to a surface point of a plurality of surface points of the anterior corneal surface, the calculations yielding a plurality of curvature values for each surface point of the plurality of surface points, wherein the curvature value for a data point is a normal vector, the normal vector representing a surface normal at the surface point corresponding to the data point;
for each surface point of the plurality of surface points, determine the curvature at the surface point from one or more curvature values for the surface point; and
generate the topography of the anterior corneal surface from the curvatures at the surface points of the anterior corneal surface.