Abstract: Systems and methods for efficiently obtaining optical coherence tomography (OCT) measurement data with reduced effects of motion are presented. One embodiment involves determining the amount of motion present during the collection of an OCT data set based on images of the eye collected at the same time as the OCT data, and recollecting select portions of the OCT data set when the amount of eye motion is determined to exceed a predetermined threshold. Another embodiment includes enabling or disabling a tracking feature based on the quality of the images available for tracking. Another embodiment includes reducing the effect of motion in the axial direction based on a comparison to a model of the eye constructed from OCT data. The method can also be used to reduce the presence of mirror image artifacts in an OCT image.

Abstract: An image data set acquired by an optical coherence tomography (OCT) system is corrected for effects due to motion of the sample. A first set of A-scans is acquired within a time short enough to avoid any significant motion of the sample. A second more extensive set of A-scans is acquired over an overlapping region on the sample. Significant sample motion may occur during acquisition of the second set. A-scans from the first set are matched with A-scans from the second set, based on similarity between the longitudinal optical scattering profiles they contain. Such matched pairs of A-scans are likely to correspond to the same region in the sample. Comparison of the OCT scanner coordinates that produced each A-scan in a matching pair, in conjunction with any shift in the longitudinal scattering profiles between the pair of A-scans, reveals the displacement of the sample between acquisition of the first and second A-scans in the pair.

Abstract: Embodiments herein include swept-source interferometric imaging systems employing arbitrary sweep patterns in which a swept-source is swept over a continuous spectral range where the variation of wavelength over time is noncontinuous. Embodiments include sweep patterns that result in reduction of signals from moving scatterers and where the sweep is synchronized with the dead time of the camera.

Abstract: Techniques for collecting and processing complex OCT data to detect localized motion contrast information with enhanced accuracy and sensitivity are presented. In a preferred embodiment, vector differences between complex OCT signals taken at the same location on the sample are used to detect blood flow in the retina. Additional embodiments involving non-linear intensity weighting of the motion contrast information, normalization of the vector difference amplitudes, and calculating the absolute value of the standard deviation of Doppler signal are described. Image processing techniques to enhance the images resulting from these motion contrast techniques are also presented.

Abstract: The present invention relates to structural analysis of the optic nerve head (ONH). In one approach, a 3D volume of intensity data which includes the optic nerve head is acquired using an optical coherence tomography (OCT) system. The vitreoretinal interface (VRI) and the optic disc margin are identified from the 3D data. The minimum area of a surface from the optic disc margin to the VRI is determined. This minimum area can be displayed as an image or in the alternative, a value corresponding to this minimum area can be displayed. The minimum area measurement provides relevant clinical information to determine the health of the eye.

Abstract: Systems and methods for efficiently obtaining optical coherence tomography (OCT) measurement data with reduced effects of motion are presented. One embodiment involves determining the amount of motion present during the collection of an OCT data set based on images of the eye collected at the same time as the OCT data, and recollecting select portions of the OCT data set when the amount of eye motion is determined to exceed a predetermined threshold. Another embodiment includes enabling or disabling a tracking feature based on the quality of the images available for tracking. Another embodiment includes reducing the effect of motion in the axial direction based on a comparison to a model of the eye constructed from OCT data. The method can also be used to reduce the presence of mirror image artifacts in an OCT image.

Abstract: A line scan imager is used to determine the motion of a subject. Each line of image data from the line scan imager is compared with a reference image. The location of a matching line in the reference image reveals the displacement of the subject. The current subject displacement can be determined based on each line of image data. The resulting displacement information can be used to correctly place other optical beams on the subject. The method can be applied to tracking the human eye to facilitate measurement, imaging, or treatment with a beam of optical radiation.

Abstract: Systems and methods for Broad Line Fundus Imaging (BLFI), an imaging approach that is a hybrid between confocal and widefield imaging systems, are presented. These systems and methods are focused on improving the quality and signal of broad line fundus images or imaging methods to create high contrast and high resolution fundus images. Embodiments related to improved pupil splitting, artifact removal, reflex minimization, adaptable field of view, instrument alignment and illumination details are considered.

Abstract: Systems and methods for applying the concept of lightfield sensors to fundus photography are presented. In one embodiment, the ability to isolate specific regions of the collected lightfield are used to reduce the effects of glare in a fundus image. Additional embodiments in which aberrations can be characterized and removed, an image from a particular plane in the collected light field is used to aid in instrument alignment, and dynamic optimization of collection pupil diameter is accomplished are also presented.

Abstract: Systems and methods for reducing the effects of motion on functional optical coherence tomography (OCT) imaging are described. Embodiments including post-processing and motion tracking are presented. A preferred embodiment in which functional OCT data is collected and analyzed for motion as a multiple scan unit is described. An extension of the invention to the collection of large field of view or montaged functional OCT data sets is also presented.

Abstract: Swept source designs that eliminate or significantly reduce artifacts in optical coherence tomography are presented. One embodiment of the present invention is a source design that frequency shifts the coherence revival interference signal to a frequency larger than the A/D detection bandwidth or the post-processing bandwidth. In another embodiment, the introduced frequency shift is large enough to introduce a Doppler shift of the modes of the laser, which causes a blurring of the comb function, and thus eliminates or reduces mode hopping. In another embodiment, adjusting the cavity optical path length prior to data acquisition depending on the given optical layout configuration to reduce or eliminate coherence revival artifacts is described.

Abstract: The present invention discloses a method for generating elevation maps or images of a tissue layer/boundary with respect to a fitted reference surface, comprising the steps of finding and segmenting a desired tissue layer/boundary; fitting a smooth reference surface to the segmented tissue layer/boundary; calculating elevations of the same or other tissue layer/boundary relative to the fitted reference surface; and generating maps of elevation relative to the fitted surface. The elevation can be displayed in various ways including three-dimensional surface renderings, topographical contour maps, contour maps, en-face color maps, and en-face grayscale maps. The elevation can also be combined and simultaneously displayed with another tissue layer/boundary dependent set of image data to provide additional information for diagnostics.

Abstract: Systems and methods for reducing noise in balanced detection based optical coherence tomography (OCT) systems are described. Embodiments including both optical hardware and electronic based solutions to spectrally filter and attenuate the source reference light in optical coherence tomography in an effort to reduce RIN and FPN noise in OCT systems are presented. A novel application to electronic balanced detection schemes in which a single source of reference detection is balanced against the interferometric signals from multiple interferometers is also presented.

Abstract: The invention relates generally to optical tomographic imaging and in particular to systems and methods for adapting the resolution of imaging. One embodiment of the present invention is an apparatus for optical coherence tomography imaging, characterized by its ability to vary the axial resolution and scanning speed during imaging.

Abstract: Methods for analyzing optical coherence tomography (OCT) images of the macula to reduce variance and improve disease diagnosis are presented. One embodiment of the invention is directed towards selecting analysis locations and data segmentation techniques to take advantage of structural homogeneities. Another embodiment is directed towards reducing the variance in a collection of normative data by transforming the individual members of the database to correspond to a Standard Macula. Variations in foveal size are corrected by radial transformation. Variations in layer thickness are corrected by axial shifting. Diagnosis is performed by comparing OCT images from a patient to the improved normative database.

Abstract: Systems and methods for reducing the effects of motion on functional optical coherence tomography (OCT) imaging are described. Embodiments including post-processing and motion tracking are presented. A preferred embodiment in which functional OCT data is collected and analyzed for motion as a multiple scan unit is described. An extension of the invention to the collection of large field of view or montaged functional OCT data sets is also presented.

Abstract: An image data set acquired by an optical coherence tomography (OCT) system is corrected for effects due to motion of the sample. A first set of A-scans is acquired within a time short enough to avoid any significant motion of the sample. A second more extensive set of A-scans is acquired over an overlapping region on the sample. Significant sample motion may occur during acquisition of the second set. A-scans from the first set are matched with A-scans from the second set, based on similarity between the longitudinal optical scattering profiles they contain. Such matched pairs of A-scans are likely to correspond to the same region in the sample. Comparison of the OCT scanner coordinates that produced each A-scan in a matching pair, in conjunction with any shift in the longitudinal scattering profiles between the pair of A-scans, reveals the displacement of the sample between acquisition of the first and second A-scans in the pair.

Abstract: A line scan imager is used to determine the motion of a subject. Each line of image data from the line scan imager is compared with a reference image. The location of a matching line in the reference image reveals the displacement of the subject. The current subject displacement can be determined based on each line of image data. The resulting displacement information can be used to correctly place other optical beams on the subject. The method can be applied to tracking the human eye to facilitate measurement, imaging, or treatment with a beam of optical radiation.

Abstract: Methods for analyzing optical coherence tomography (OCT) images of the macula to reduce variance and improve disease diagnosis are presented. One embodiment of the invention is directed towards selecting analysis locations and data segmentation techniques to take advantage of structural homogeneities. Another embodiment is directed towards reducing the variance in a collection of normative data by transforming the individual members of the database to correspond to a Standard Macula. Variations in foveal size are corrected by radial transformation. Variations in layer thickness are corrected by axial shifting. Diagnosis is performed by comparing OCT images from a patient to the improved normative database.

Abstract: The invention relates generally to optical tomographic imaging and in particular to systems and methods for adapting the resolution of imaging. One embodiment of the present invention is an apparatus for optical coherence tomography imaging, characterized by its ability to vary the axial resolution and scanning speed during imaging.