Detection of missampled interferograms in frequency domain OCT with a k-clock
First Claim
1. A method for imaging with frequency domain optical coherence tomography (OCT) imaging system having a reference arm, a sample arm, and a detection arm, comprising the steps of:
- using an optical detector of the detection arm to obtain a plurality of interferograms formed by an interference of light from the sample arm and the reference arm, each of the plurality of interferograms comprising at least two optically generated reference signals corresponding to different wavelengths;
digitizing each of the plurality of interferograms such that each digitized interferogram comprises a first digital sample of a first of the at least two reference signals and a second digital sample of a second of the at least two reference signals, the first digital sample being at a first sample number and the second digital sample being at a second sample number;
for each digitized interferogram, determining an absolute value of a difference between the first sample number and the second sample number;
identifying a digitized interferogram as having a digitization error if the determined absolute value of the difference for that digitized interferogram does not match the determined absolute value of the difference for a statistically significant number of digitized interferograms; and
correcting, replacing, or discarding any identified digitized interferograms.
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Accused Products
Abstract
Optical coherence tomography light sources can be non-linear and attempts to linearize them can lead to asynchrony between the light source and A-line scans and missampling in the scans causing signal noise. Accordingly, a system and methods are provided herein to detect missampling by obtaining a plurality of interferograms; providing at least two wavenumber reference signals at different wavenumbers, wherein the wavenumber reference signals comprise attenuated or enhanced portions of each of the plurality of interferograms; aligning each of the plurality of interferograms according to one of the at least two wavenumber reference signals; and for each of the plurality of interferograms, identifying an interferogram as missampled if another of the at least two reference signals does not align with a corresponding reference signal in a statistically significant number of the plurality of interferograms. An optical element, for example, an optical notch, may be used to generate the reference signals.
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Citations
16 Claims
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1. A method for imaging with frequency domain optical coherence tomography (OCT) imaging system having a reference arm, a sample arm, and a detection arm, comprising the steps of:
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using an optical detector of the detection arm to obtain a plurality of interferograms formed by an interference of light from the sample arm and the reference arm, each of the plurality of interferograms comprising at least two optically generated reference signals corresponding to different wavelengths; digitizing each of the plurality of interferograms such that each digitized interferogram comprises a first digital sample of a first of the at least two reference signals and a second digital sample of a second of the at least two reference signals, the first digital sample being at a first sample number and the second digital sample being at a second sample number; for each digitized interferogram, determining an absolute value of a difference between the first sample number and the second sample number; identifying a digitized interferogram as having a digitization error if the determined absolute value of the difference for that digitized interferogram does not match the determined absolute value of the difference for a statistically significant number of digitized interferograms; and correcting, replacing, or discarding any identified digitized interferograms. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A frequency domain optical coherence tomography (OCT) imaging system comprising:
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a light source; a reference arm; a sample arm; a detection arm; at least one optical element; an optical detector of the detection arm configured to obtain a plurality of interferograms formed by an interference of light from the sample arm and the reference arm, each of the plurality of interferograms comprising at least two optically generated reference signals corresponding to different wavelengths, the at least two optically generated reference signals being generated by the at least one optical element; a data acquisition device configured to digitize each of the plurality of interferograms such that each digitized interferogram comprises a first digital sample of a first of the at least two reference signals and a second digital sample of a second of the at least two reference signals, the first digital sample being at a first sample number and the second digital sample being at a second sample number; and a processor configured to; for each digitized interferogram, determine an absolute value of a difference between the first sample number and the second sample number; identify a digitized interferogram as having a digitization error if the determined absolute value of the difference for that digitized interferogram does not match the determined absolute value of the difference for a statistically significant number of digitized interferograms; and correct, replace, or discard any identified digitized interferograms. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification