Method to suppress artifacts in frequency-domain optical coherence tomography
First Claim
Patent Images
1. A method for suppressing artifacts in the image of frequency domain optical coherence tomography, comprising the steps of:
- providing a sample path and a reference path that differ in their chromatic dispersion so as to create a variation in relative group delay as a function of optical frequency between the sample and reference paths, wherein the relative group delay variation across the range of optical frequencies recorded is greater than ten times the axial resolution of the optical coherence tomography system;
separating optical radiation from an optical radiation source among the sample path and the reference path;
measuring as a function of optical frequency the combined radiation returned from the sample and reference paths, the measurement producing an interference spectrum;
multiplying the measured interference spectrum by a complex phase factor to compensate for the mismatch in chromatic dispersion; and
processing the compensated interference spectrum to obtain information on the reflectance distribution in the sample path.
1 Assignment
0 Petitions
Accused Products
Abstract
One embodiment of the present invention is a method for suppressing artifacts in frequency-domain OCT images, which method includes (a) providing sample and reference paths with a significant difference in their chromatic dispersion (b) correcting for the effects of the mismatch in chromatic dispersion, for the purpose of making artifacts in the OCT image readily distinguishable from the desired image.
-
Citations
18 Claims
-
1. A method for suppressing artifacts in the image of frequency domain optical coherence tomography, comprising the steps of:
-
providing a sample path and a reference path that differ in their chromatic dispersion so as to create a variation in relative group delay as a function of optical frequency between the sample and reference paths, wherein the relative group delay variation across the range of optical frequencies recorded is greater than ten times the axial resolution of the optical coherence tomography system;
separating optical radiation from an optical radiation source among the sample path and the reference path;
measuring as a function of optical frequency the combined radiation returned from the sample and reference paths, the measurement producing an interference spectrum;
multiplying the measured interference spectrum by a complex phase factor to compensate for the mismatch in chromatic dispersion; and
processing the compensated interference spectrum to obtain information on the reflectance distribution in the sample path. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A method for suppressing artifacts in the image of frequency domain optical coherence tomography, comprising the steps of:
-
providing a sample path and a reference path that differ in their chromatic dispersion so as to create a relative group delay variation as a function of optical frequency between the sample and reference paths;
separating optical radiation from an optical radiation source among the sample path and the reference path;
positioning a sample to return both optical radiation with optical path length longer than the reference optical path length, and optical radiation with optical path length shorter than the reference optical path length;
measuring as a function of optical frequency the combined radiation returned from the sample and reference paths, the measurement producing an interference spectrum;
processing the measured interference spectrum to compensate for the mismatch in chromatic dispersion and using the compensated interference spectrum to obtain information on the reflectance distribution in the sample path;
generating an image based on the information on the reflectance distribution to allow the actual reflectance distribution corresponding to sample features to be distinguished from artifacts of the frequency domain optical coherence tomography measurement; and
repositioning the sample to separate the image of the actual sample features from the artifacts of the frequency domain optical coherence tomography measurement. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
-
-
18. A method for suppressing artifacts in frequency domain optical coherence tomography comprising the steps of:
-
providing a sample path and a reference path that differ in their chromatic dispersion so as to create a relative group delay variation as a function of optical frequency between the sample and reference paths;
separating optical radiation from an optical radiation source among the sample path and the reference path;
measuring at a sequence of discrete optical frequencies the combined radiation returned from the sample and reference paths, the measurements producing an interference spectrum, wherein the measurements are taken with non-uniform spacing in optical frequency; and
processing the resulting interference spectrum to obtain information on the reflectance distribution in the sample path wherein the difference in chromatic dispersion is chosen such that a reflection site at a chosen depth in the sample path produces interference fringes that are uniformly spaced in the sequence of discrete optical frequencies used for the measurements.
-
Specification