US 10,376,139 B2
Systems and methods for improved ease and accuracy of gaze tracking
Harihar Narasimha-Iyer, Livermore, CA (US); Vincent Michael Patella, Albany, CA (US); and Goran Anders Johansson, San Francisco, CA (US)
Assigned to CARL ZEISS MEDITEC, INC., Dublin, CA (US)
Filed by Carl Zeiss Meditec, Inc., Dublin, CA (US)
Filed on Jan. 10, 2018, as Appl. No. 15/867,376.
Application 15/867,376 is a division of application No. 14/919,491, filed on Oct. 21, 2015, granted, now 9,872,615, issued on Jan. 23, 2018.
Application 14/919,491 is a continuation of application No. 13/781,051, filed on Feb. 28, 2013, granted, now 9,179,833, issued on Nov. 10, 2015.
Prior Publication US 2018/0132713 A1, May 17, 2018
This patent is subject to a terminal disclaimer.
Int. Cl. A61B 3/00 (2006.01); A61B 3/113 (2006.01); A61B 3/024 (2006.01); G06F 3/01 (2006.01); G06K 9/00 (2006.01); A61B 3/107 (2006.01); A61B 3/14 (2006.01)
CPC A61B 3/0091 (2013.01) [A61B 3/0008 (2013.01); A61B 3/0025 (2013.01); A61B 3/0041 (2013.01); A61B 3/024 (2013.01); A61B 3/107 (2013.01); A61B 3/113 (2013.01); A61B 3/14 (2013.01); G06F 3/013 (2013.01); G06K 9/00604 (2013.01); A61B 3/0083 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A method for determining a subject's gaze direction during a visual field test using a perimeter, wherein the subject is asked to fixate on a specification location, comprising:
using one or more light sources to create one or more reflections from an ocular surface;
collecting images of the subject's eye with a camera;
determining a shape descriptor for the subject's eye by analyzing one or more reflections of the light sources in a collected image;
accessing a database comprising a set of reference eyes, the reference eyes having different shapes, each reference eye having an associated shape descriptor and a set of calibration data, said calibration data including gaze descriptors that are correlated to particular gaze directions, with tea relationship between the gaze descriptors and the gaze directions being characterized by a mapping function;
comparing the determined shape descriptor for the subject's eye to predetermined the shape descriptors associated with the reference eyes in the database to determine one or more matches;
displaying a series of test stimuli to the subject;
collecting responses to the stimuli from the subject;
analyzing the responses to determine the sensitivity of the subject's visual field;
determining a gaze descriptor for the subject's eye for each test stimulus by analyzing the reflections of the light sources in an image collected when the stimulus was displayed;
inputting the gaze descriptor for the subject's eye for each test stimulus into a predetermined mapping function determined from the one or more matched reference eyes to determine the subject's gaze direction during each test stimulus; and
for any response to a test stimulus wherein the determined gaze direction deviates from the specific location by a predetermined threshold, performing one of the following steps:
(a) disregarding the response;
(b) flagging the response to a clinician; or
(c) reassigning the response to a different location.