Abstract: Various balanced detection systems which reduce alignment requirements of free space optics based balanced detection configurations are discussed. One example system includes a light source, a beam divider, sample optics, return optics, and a processor. The light source generates a light beam. The beam divider separates the light beam into reference and sample arms. The sample optics deliver the light beam in the sample arm to a light scattering object to be imaged. The return optics direct light to a balanced detection system, which has a balanced detection beam divider for combining light scattered from the object and light from the reference arm and directing the combined light into two detection channels and two detectors for collecting the combined light in the two detection channels and generating signals in response thereto. The processor processes the signals and generates image data of the object based on the processed signals.

Abstract: Improved line-field imaging systems incorporating planar waveguides are presented. In one embodiment the optics of the system are configured such that a line of light on the light scattering object is imaged to the planar waveguide in at least one dimension. Embodiments where the waveguide incorporates a beamsplitter of an interferometer, where the beam divider and waveguide are referenced to one or more common surfaces, and wherein the source and waveguide are optically coupled, are also considered. In another embodiment, the planar waveguide is in contact or close proximity to the light scattering object.

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: 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: Efficient interferometer designs for optical coherence tomography (OCT) systems are presented. One example interferometer design includes two polarization dependent beamsplitters and a non-polarization dependent combiner. The first polarization dependent beamsplitter transmits light in a first polarization state to a sample arm of the OCT system and transmits light in a second polarization state different from the first polarization state to a reference arm of the system. The second polarization dependent beamsplitter transmits light returning from a sample to the non-polarization dependent combiner. The combiner combines light returned from the sample and the light that has passed through the reference arm, which is then detected at a detector. Another example interferometer design includes free space optics comprising a non-reciprocal beamsplitting element in a beam path from a light source to a sample.

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: 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: 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: Systems and methods for improved interferometric imaging are presented. One embodiment is a partial field frequency-domain interferometric imaging system in which a light beam is scanned in two directions across a sample and the light scattered from the object is collected using a spatially resolved detector. The light beam could illuminate a spot, a line or a two-dimensional area on the sample. Additional embodiments with applicability to partial field as well as other types of interferometric systems are also presented.

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: An optical coherence tomography device is disclosed for improved imaging. Reduced levels of speckle in the images generated by the device are obtained by forming a B-scan from a plurality of A-scans, wherein each resolution cell of the B-scan is generated through compounding of a subset of the A-scans and wherein at least some of the subset of A-scans are separated by at least half the diameter of a speckle cell both tangent to and orthogonal to the B-scan at that cell.

Abstract: Efficient interferometer designs for optical coherence tomography (OCT) systems are presented. One example interferometer design includes two polarization dependent beamsplitters and a non-polarization dependent combiner. The first polarization dependent beamsplitter transmits light in a first polarization state to a sample arm of the OCT system and transmits light in a second polarization state different from the first polarization state to a reference arm of the system. The second polarization dependent beamsplitter transmits light returning from a sample to the non-polarization dependent combiner. The combiner combines light returned from the sample and the light that has passed through the reference arm, which is then detected at a detector. Another example interferometer design includes free space optics comprising a non-reciprocal beamsplitting element in a beam path from a light source to a sample.

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: Continuous time or non-integrating operation of an array of photosensitive elements for use as a detector in frequency domain interferometric imaging systems is described. Both swept-source and spectral domain embodiments are presented. Non-integrating or continuous mode camera operation enables much higher camera read-out rates compared to interferometric imaging systems using conventionally operated CMOS or CCD cameras.

Abstract: Improved line-field imaging systems incorporating planar waveguides are presented. In one embodiment the optics of the system are configured such that a line of light on the light scattering object is imaged to the planar waveguide in at least one dimension. Embodiments where the waveguide incorporates a beamsplitter of an interferometer, where the beam divider and waveguide are referenced to one or more common surfaces, and wherein the source and waveguide are optically coupled, are also considered. In another embodiment, the planar waveguide is in contact or close proximity to the light scattering object.

Abstract: A novel imaging method, line-field holoscopy is presented. A line of light is projected across an object to be investigated through an imaging system. The light scattered from the investigated object is combined with reference radiation. The combined light is projected onto a detector providing a confocal restriction in one dimension. Astigmatic optics in the return path transform the light asymmetrically such that at the detector, the line focus is imaged to the confocal restriction, while the orthogonal direction is defocused. Embodiments including a swept source with linear detection array, and spectrometer based systems utilizing a 2D detector array are described. The data may be reconstructed to a B-scan by two-dimensional Fourier transform or other reconstruction method with or without combination of more complex algorithms.

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: Split Integration Mode (SIM) acquisition schemes are presented that enable optical coherence tomography (OCT) imaging at multiple rates. SIM enables a system and method of operation having a first mode and a second mode, wherein the fundamental acquisition rate of the detector is the same in the two modes, but wherein the generated signals in the second mode are digitally combined prior to signal processing to create a data set with an effective acquisition rate less than the fundamental acquisition rate.

Abstract: Split Integration Mode (SIM) acquisition schemes are presented that enable optical coherence tomography (OCT) imaging at multiple rates. SIM enables a system and method of operation having a first mode and a second mode, wherein the fundamental acquisition rate of the detector is the same in the two modes, but wherein the generated signals in the second mode are digitally combined prior to signal processing to create a data set with an effective acquisition rate less than the fundamental acquisition rate.

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.