Characterization of retinal parameters by circular profile analysis
AssigneeTopcon Medical Systems, Inc.
InventorsYijun Huang, Tetsuyoshi Royama, Alexandre Kotchkin
Life of this patent
Estimating the term…
Abstract
Certain diseases of the retina are diagnosed by circular profile analysis of retinal parameters, such as thickness. Retinal thickness around a user-defined circle on the retina is measured by three-dimensional optical coherence tomography or other ophthalmological techniques. Abnormally thin regions are identified by comparing a measured function of thickness vs. polar angle to a reference function of thickness vs. polar angle. A degree of abnormality is characterized by the ratio of the integral of the measured thickness function to the integral of the reference thickness function over the abnormally thin region, as specified by a range of polar angles.
Claims31
A method for characterizing a retinal parameter as a function of polar angle θ, the method comprising the steps of:
- determining a first interval of polar angles bounded by a first polar angle and a second polar angle wherein, at each polar angle within the first interval, the value of a first measurement parameter function is less than the value of a reference parameter function;
- calculating a first integral comprising an integral of the reference parameter function over the first interval;
- calculating a second integral comprising an integral of the first measurement parameter function over the first interval;
- and
- calculating a first characterization value based at least in part on the first integral and the second integral.
An apparatus for characterizing a retinal parameter as a function of polar angle θ, the apparatus comprising:
- means for determining a first interval of polar angles bounded by a first polar angle and a second polar angle wherein, at each polar angle within the first interval, the value of a first measurement parameter function is less than the value of a reference parameter function;
- means for calculating a first integral comprising an integral of the reference parameter function over the first interval;
- means for calculating a second integral comprising an integral of the first measurement parameter function over the first interval;
- and
- means for calculating a first characterization value based at least in part on the first integral and the second integral.
A non-transitory computer readable medium storing computer program instructions for characterizing a retinal parameter as a function of polar angle θ, the computer program instructions defining the steps of:
- determining a first interval of polar angles bounded by a first polar angle and a second polar angle wherein, at each polar angle within the first interval, the value of a first measurement parameter function is less than the value of a reference parameter function;
- calculating a first integral comprising an integral of the reference parameter function over the first interval;
- calculating a second integral comprising an integral of the first measurement parameter function over the first interval;
- and
- calculating a first characterization value based at least in part on the first integral and the second integral.
Dependencies are inferred from the claim text.