摘要:
Methods, fourier domain optical coherence tomography (FDOCT) interferometers and computer program products are provided for removing undesired artifacts in FDOCT systems using continuous phase modulation. A variable phase delay is introduced between a reference arm and a sample arm of an FDOCT interferometer using continuous phase modulation. Two or more spectral interferograms having different phase delay integration times are generated. The spectral interferograms are combined using signal processing to remove the undesired artifacts. Systems and methods for switching between stepped and continuous phase shifting Fourier domain optical coherence tomography (FDOCT) and polarization-sensitive optical coherence tomography (PSOCT) are also provided herein.
摘要:
Optical coherence tomography (OCT) imaging systems for imaging an eye are provided including a source having an associated source arm path and a reference arm having an associated reference arm path coupled to the source path, the reference arm path having an associated reference arm path length. A sample having an associated sample arm path coupled to the source arm and reference arm paths is provided. A reference arm path length adjustment module is coupled to the reference arm. The reference arm path length adjustment module is configured to automatically adjust the reference arm path length such that the reference arm path length is based on an eye length of the subject. Related methods and computer program products are also provided.
摘要:
A surgical microscope assembly includes a microscope main objective and microscope imaging optics. The microscope main objective and microscope imaging optics define a viewing beam path that passes from a sample through the microscope main objective and the microscope imaging optics. The assembly includes an optical coherence tomography (OCT) unit having an illumination beam and a collection beam and a beamsplitter between the microscope main objective and the microscope imaging optics. The beamsplitter is configured to direct a portion of light from the microscope main objective to the microscope imaging optics and to direct another portion of light from the microscope main objective to the OCT unit collection beam. The beamsplitter is further configured to direct an illumination beam from the OCT unit to the microscope main objective and to the sample. A beam forming unit is between the OCT unit and the beamsplitter. The beam forming unit is configured to form the illumination beam of the OCT unit so as to generally correspond to a size of the microscope main objective.
摘要:
A method is described for determining depth-resolved backscatter characteristics of scatterers within a sample, comprising the steps of: acquiring a plurality of sets of cross-correlation interferogram data using an interferometer having a sample arm with the sample in the sample arm, wherein the sample includes a distribution of scatterers therein, and wherein the acquiring step includes the step of altering the distribution of scatterers within the sample with respect to the sample arm for substantially each acquisition; and averaging, in the Fourier domain, the cross-correlation interferogram data, thereby revealing backscattering characteristics of the scatterers within the sample.
摘要:
Disclosed herein are systems and method for segmentation and identification of structured features in images. According to an aspect, a method may include representing an image as a graph of nodes connected together by edges. For example, the image may be an ocular image showing layered structures or other features of the retina. The method may also include adding, to the graph, nodes adjacent to nodes along first and second sides of the graph. The added nodes may have edge weights less than the nodes along the first and second sides of the graph. Further, the method may include assigning start and end points to any of the added nodes along the first and second sides, respectively. The method may also include graph cutting between the start and end points for identifying a feature in the image.
摘要:
An interferometer system includes an optical radiation source, an optical circulator connected between the optical radiation source and a sample location for transmitting optical radiation from the optical radiation source to the sample location, an output of the optical circulator connected to direct optical radiation to an optical detector. Various embodiments of such a system are possible. A method of performing OCDR or OCT imaging of a sample which involves the steps of: (a) producing low coherence optical radiation; (b) directing at least some of the low coherence optical radiation through an optical circulator to the sample; (c) reflecting at least some of the low coherence optical radiation off of the sample; and (d) detecting at least some of the reflected low coherence optical radiation and producing an electrical signal corresponding thereto.
摘要:
A method is described for determining depth-resolved backscatter characteristics of scatterers within a sample, comprising the steps of: acquiring a plurality of sets of cross-correlation interferogram data using an interferometer having a sample arm with the sample in the sample arm, wherein the sample includes a distribution of scatterers therein, and wherein the acquiring step includes the step of altering the distribution of scatterers within the sample with respect to the sample arm for substantially each acquisition; and averaging, in the Fourier domain, the cross-correlation interferogram data, thereby revealing backscattering characteristics of the scatterers within the sample.
摘要:
Systems and methods are disclosed for optical coherence tomography (OCT). For example, imaging can use optical phase modulators based on optical delay lines that, in conjunction with a swept-source laser, can be used to achieve heterodyne swept source optical coherence tomography (SSOCT). These techniques resolve the complex conjugate ambiguity in SSOCT, thereby doubling the usable imaging range. This increased imaging range has numerous important clinical applications in ophthalmology, cardiology and radiology, as well as applications in small animal and non-biological imaging. These methods are superior to prior disclosed methods requiring acousto-optic or electro-optic modulators with respect to complexity, efficiency, imaging speed and image quality.
摘要:
Disclosed herein are systems and method for segmentation and identification of structured features in images. According to an aspect, a method may include representing an image as a graph of nodes connected together by edges. For example, the image may be an ocular image showing layered structures or other features of the retina. The method may also include adding, to the graph, nodes adjacent to nodes along first and second sides of the graph. The added nodes may have edge weights less than the nodes along the first and second sides of the graph. Further, the method may include assigning start and end points to any of the added nodes along the first and second sides, respectively. The method may also include graph cutting between the start and end points for identifying a feature in the image.
摘要:
A system for imaging a sample is provided that includes an optical coherence tomography (OCT) portion having an associated OCT path. A second imaging portion is provided having an associated second image path, different from the OCT path. A fixation target having an associated fixation path, different from the second image path and the OCT path is also provided. The OCT path, the second image path and the fixation path are confocal at a common image plane. Related handheld systems are also provided.