1. Articles from r. daniel ferguson

    1-26 of 26
    1. IMAGING WITH MULTIMODAL ADAPTIVE-OPTICS OPTICAL COHERENCE TOMOGRAPHY IN MULTIPLE EVANESCENT WHITE DOT SYNDROME: THE STRUCTURE AND FUNCTIONAL RELATIONSHIP

      IMAGING WITH MULTIMODAL ADAPTIVE-OPTICS OPTICAL COHERENCE TOMOGRAPHY IN MULTIPLE EVANESCENT WHITE DOT SYNDROME: THE STRUCTURE AND FUNCTIONAL RELATIONSHIP

      Purpose: To elucidate the location of pathological changes in multiple evanescent white dot syndrome (MEWDS) with the use of multimodal adaptive optics (AO) imaging . Methods: A 5-year observational case study of a 24-year-old female with recurrent MEWDS. Full examination included history, Snellen chart visual acuity, pupil assessment, intraocular pressures, slit lamp evaluation, dilated fundoscopic exam, imaging with Fourier-domain optical coherence tomography (FD-OCT), blue-light fundus autofluorescence (FAF), fundus photography, fluorescein angiography, and adaptive-optics optical coherence tomography . Results: Three distinct acute episodes of MEWDS occurred during the period of follow-up. Fourier-domain optical coherence tomography and adaptive-optics imaging showed disturbance in the photoreceptor ...

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    2. Combined Reflectance Confocal Microscopy-Optical Coherence Tomography System for Imaging of Biological Tissue

      Combined Reflectance Confocal Microscopy-Optical Coherence Tomography System for Imaging of Biological Tissue

      A dual-modality apparatus for imaging of biological tissue includes a reflectance confocal microscopy (RCM) imaging apparatus and an optical coherence tomography (OCT) imaging apparatus. A first optical component reflects a first beam of light provided by a RCM imaging apparatus towards a sample and passes a second beam of light provided by an OCT imaging apparatus towards the sample, such that the first and second beam of lights share at least a portion of an imaging path.

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    3. Adaptive optics optical coherence tomography with dynamic retinal tracking

      Adaptive optics optical coherence tomography with dynamic retinal tracking

      Adaptive optics optical coherence tomography (AO-OCT) is a highly sensitive and noninvasive method for three dimensional imaging of the microscopic retina. Like all in vivo retinal imaging techniques, however, it suffers the effects of involuntary eye movements that occur even under normal fixation. In this study we investigated dynamic retinal tracking to measure and correct eye motion at KHz rates for AO-OCT imaging. A customized retina tracking module was integrated into the sample arm of the 2nd-generation Indiana AO-OCT system and images were acquired on three subjects. Analyses were developed based on temporal amplitude and spatial power spectra in conjunction ...

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    4. Multi-functional adaptive optics retinal imaging

      Multi-functional adaptive optics retinal imaging

      An optical apparatus includes a system of optical components capable of operating in a scanning laser ophthalmoscope (SLO) mode and an optical coherence tomography (OCT) mode. The system of optical components includes a first optical module for the SLO mode, a second optical module for the OCT mode, and a first scanning device. The first optical module for the SLO mode includes a first source adapted to provide a first imaging beam for the SLO mode and a first detection device configured to receive a first signal associated with a first image of a retina of an eye. The second ...

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    5. Repeatability of in vivo 3D lamina cribrosa microarchitecture using adaptive optics spectral domain optical coherence tomography

      Repeatability of in vivo 3D lamina cribrosa microarchitecture using adaptive optics spectral domain optical coherence tomography

      We demonstrate the repeatability of lamina cribrosa (LC) microarchitecture for in vivo 3D optical coherence tomography (OCT) scans of healthy, glaucoma suspects, and glaucomatous eyes. Eyes underwent two scans using a prototype adaptive optics spectral domain OCT (AO-SDOCT) device from which LC microarchitecture was semi-automatically segmented. LC segmentations were used to quantify pore and beam structure through several global microarchitecture parameters. Repeatability of LC microarchitecture was assessed qualitatively and quantitatively by calculating parameter imprecision. For all but one parameters (pore volume) measurement imprecision was <4.7% of the mean value, indicating good measurement reproducibility. Imprecision ranged between 27.3% and ...

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    6. Optical coherence tomography-based micro-particle image velocimetry

      Optical coherence tomography-based micro-particle image velocimetry

      We present a new application of optical coherence tomography (OCT), widely used in biomedical imaging, to flow analysis in near-wall hydrodynamics for marine research. This unique capability, called OCT micro-particle image velocimetry, provides a high-resolution view of microscopic flow phenomena and measurement of flow statistics within the first millimeter of a boundary layer. The technique is demonstrated in a small flow cuvette and in a water tunnel.

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    7. Automated lamina cribrosa microstructural segmentation in optical coherence tomography scans of healthy and glaucomatous eyes

      Automated lamina cribrosa microstructural segmentation in optical coherence tomography scans of healthy and glaucomatous eyes

      We demonstrate an automated segmentation method for in-vivo 3D optical coherence tomography (OCT) imaging of the lamina cribrosa (LC). Manual segmentations of coronal slices of the LC were used as a gold standard in parameter selection and evaluation of the automated technique. The method was validated using two prototype OCT devices; each had a subject cohort including both healthy and glaucomatous eyes. Automated segmentation of in-vivo 3D LC OCT microstructure performed comparably to manual segmentation and is useful for investigative research and in clinical quantification of the LC.

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    8. Accurate prediction of collapse temperature using optical coherence tomography-based freeze-drying microscopy

      Accurate prediction of collapse temperature using optical coherence tomography-based freeze-drying microscopy

      The objective of this study was to assess the feasibility of developing and applying a laboratory tool that can provide three-dimensional product structural information during freeze-drying and which can accurately characterize the collapse temperature ( T c ) of pharmaceutical formulations designed for freeze-drying. A single-vial freeze dryer coupled with optical coherence tomography freeze-drying microscopy (OCT–FDM) was developed to investigate the structure and T c of formulations in pharmaceutically relevant products containers (i.e., freeze-drying in vials). OCT–FDM was used to measure the T c and eutectic melt of three formulations in freeze-drying vials. The T c as measured by ...

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    9. Combined reflectance confocal microscopy/optical coherence tomography imaging for skin burn assessment

      Combined reflectance confocal microscopy/optical coherence tomography imaging for skin burn assessment

      A combined high-resolution reflectance confocal microscopy (RCM)/optical coherence tomography (OCT) instrument for assessing skin burn gravity has been built and tested. This instruments allows for visualizing skin intracellular details with submicron resolution in the RCM mode and morphological and birefringence modifications to depths on the order of 1.2 mm in the OCT mode. Preliminary testing of the dual modality imaging approach has been performed on the skin of volunteers with some burn scars and on normal and thermally-injured Epiderm FTTM skin constructs. The initial results show that these two optical technologies have complementary capabilities that can offer the ...

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    10. Multimodal adaptive optics retinal imager: design and performance

      Multimodal adaptive optics retinal imager: design and performance

      Optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO) are complementary imaging modalities, the combination of which can provide clinicians with a wealth of information to detect retinal diseases, monitor disease progression, or assess new therapies. Adaptive optics (AO) is a tool that enables correction of wavefront distortions from ocular aberrations. We have developed a multimodal adaptive optics system (MAOS) for high-resolution multifunctional use in a variety of research and clinical applications. The system integrates both OCT and SLO imaging channels into an AO beam path. The optics and hardware were designed with specific features for simultaneous SLO/OCT output ...

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    11. Adaptive optics line scanning ophthalmoscope

      Adaptive optics line scanning ophthalmoscope

      A first optical module scans a portion of an eye with a line of light, descans reflected light from the scanned portion of the eye and confocally provides output light in a line focus configuration. A detection device detects the output light and images the portion of the eye. A second optical module detects an optical distortion and corrects the optical distortion in the line of light scanned on the portion of the eye.

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    12. Imaging flow dynamics in murine coronary arteries with spectral domain optical Doppler tomography

      Imaging flow dynamics in murine coronary arteries with spectral domain optical Doppler tomography

      Blood flow in murine epicardial and intra-myocardial coronary arteries was measured in vivo with spectral domain optical Doppler tomography (SD-ODT). Videos at frame rates up to 180 fps were collected and processed to extract phase shifts associated with moving erythrocytes in the coronary arteries. Radial averaging centered on the vessel lumen provided spatial smoothing of phase noise in a single cross-sectional frame for instantaneous peak velocity measurement without distortion of the flow profile. Temporal averaging synchronized to the cardiac cycle (i.e., gating) was also performed to reduce phase noise, although resulting in lower flow profiles. The vessel angle with ...

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    13. Fluorescence-guided optical coherence tomography imaging for colon cancer screening: a preliminary mouse study

      Fluorescence-guided optical coherence tomography imaging for colon cancer screening: a preliminary mouse study

      A new concept for cancer screening has been preliminarily investigated. A cancer targeting agent loaded with a near-infrared (NIR) dye was topically applied on the tissue to highlight cancer-suspect locations and guide optical coherence tomography (OCT) imaging, which was used to further investigate tissue morphology at the micron scale. A pilot study on ApcMin mice has been performed to preliminarily test this new cancer screening approach. As a cancer-targeting agent, poly(epsilon-caprolactone) microparticles (PCLMPs), labeled with a NIR dye and functionalized with an RGD (argenine-glycine-aspartic acid) peptide, were used. This agent recognizes the ανβ3 integrin receptor (ABIR), which is over-expressed ...

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    14. Optical coherence tomography-based freeze-drying microscopy

      Optical coherence tomography-based freeze-drying microscopy

      A new type of freeze-drying microscope based upon time-domain optical coherence tomography is presented here (OCT-FDM). The microscope allows for real-time, in situ 3D imaging of pharmaceutical formulations in vials relevant for manufacturing processes with a lateral resolution of <7 μm and an axial resolution of <5 μm. Correlation of volumetric structural imaging with product temperature measured during the freeze-drying cycle allowed investigation of structural changes in the product and determination of the temperature at which the freeze-dried cake collapses. This critical temperature is the most important parameter in designing freeze-drying processes of pharmaceutical products.

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    15. Multi-Functional Adaptive Optics Retinal Imaging

      Multi-Functional Adaptive Optics Retinal Imaging

      An optical apparatus includes a system of optical components capable of operating in a scanning laser ophthalmoscope (SLO) mode and an optical coherence tomography (OCT) mode. The system of optical components includes a first optical module for the SLO mode, a second optical module for the OCT mode, and a first scanning device. The first optical module for the SLO mode includes a first source adapted to provide a first imaging beam for the SLO mode and a first detection device configured to receive a first signal associated with a first image of a retina of an eye. The second ...

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    16. Differentiation of pancreatic cysts with optical coherence tomography (OCT) imaging: an ex vivo pilot study

      Differentiation of pancreatic cysts with optical coherence tomography (OCT) imaging: an ex vivo pilot study

      We demonstrate for the first time that optical coherence tomography (OCT) imaging can reliably distinguish between morphologic features of low risk pancreatic cysts (i.e., pseudocysts and serous cystadenomas) and high risk pancreatic cysts (i.e., mucinous cystic neoplasms and intraductal papillary mucinous neoplasms). In our study fresh pancreatectomy specimens (66) from patients with cystic lesions undergoing surgery were acquired and examined with OCT. A training set of 20 pathology-OCT correlated tissue specimens were used to develop criteria for differentiating between low and high risk cystic lesions. A separate (validation) set of 46 specimens were used to test the OCT ...

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    17. Hybrid spectral domain optical coherence tomography line scanning laser ophthalmoscope

      Hybrid spectral domain optical coherence tomography line scanning laser ophthalmoscope
      An apparatus for imaging an eye includes a housing and a system of optical components disposed in the housing. The apparatus is capable of operating in a line scanning laser ophthalmoscope (LSLO) mode and an optical coherence tomography (OCT) mode. The system of optical components can include a first source to provide a first beam of light for the OCT mode and a second source to provide a second beam of light for the LSLO mode. In the OCT mode, a first optic is used that (i) scans, using a first surface of the first optic, the first beam of ...
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    18. Preliminary evaluation of a nanotechnology-based approach for the more effective diagnosis of colon cancers

      Preliminary evaluation of a nanotechnology-based approach for the more effective diagnosis of colon cancers

      Aim: The goal of this research was to develop and preliminarily test a novel technology and instrumentation that could help to significantly increase the diagnostic yield of current colon cancer screening procedures. This technology is based on a combined fluorescence–optical coherence tomography (OCT) imaging, and topical delivery of a cancer-targeting agent. Materials & methods: Gold colloid-adsorbed poly(ε-caprolactone) microparticles were labeled with a near-infrared dye, and functionalized with argentine–glycine–aspartic acid (RGD peptide) to effectively target cancer tissue, and enhance fluorescence-imaging contrast. The RGD peptide recognizes the αvβ3-integrin receptor, which is overexpressed by epithelial cancer cells. OCT was ...

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    19. Stabilized retinal imaging with adaptive optics

      Stabilized retinal imaging with adaptive optics
      A system provides an optical image of an object. A first module tracks a reference feature of the object. A second module includes a source for an imaging beam, a scanning device to move the imaging beam along a portion of the object and a detection device receives a signal associated with an image of the portion of the object. The first module controls the position of the imaging beam relative to the reference feature to correct for the motion of the object. A third module detects a distortion of the object and compensates for the distortion.
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    20. High resolution multimodal clinical ophthalmic imaging system

      High resolution multimodal clinical ophthalmic imaging system

      We developed a multimodal adaptive optics (AO) retinal imager which is the first to combine high performance AO-corrected scanning laser ophthalmoscopy (SLO) and swept source Fourier domain optical coherence tomography (SSOCT) imaging modes in a single compact clinical prototype platform. Such systems are becoming ever more essential to vision research and are expected to prove their clinical value for diagnosis of retinal diseases, including glaucoma, diabetic retinopathy (DR), age-related macular degeneration (AMD), and retinitis pigmentosa. The SSOCT channel operates at a wavelength of 1 µm for increased penetration and visualization of the choriocapillaris and choroid, sites of major disease activity ...

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    21. Hybrid spectral domain optical coherence tomography line scanning laser ophthalmoscope

      Hybrid spectral domain optical coherence tomography line scanning laser ophthalmoscope
      An apparatus for imaging an eye includes a housing and a system of optical components disposed in the housing. The apparatus is capable of operating in a line scanning laser ophthalmoscope (LSLO) mode and an optical coherence tomography (OCT) mode. The system of optical components can include a first source to provide a first beam of light for the OCT mode and a second source to provide a second beam of light for the LSLO mode. In the OCT mode, a first optic is used that (i) scans, using a first surface of the first optic, the first beam of ...
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    22. Automated algorithm for breast tissue differentiation in optical coherence tomography

      An automated algorithm for differentiating breast tissue types based on optical coherence tomography (OCT) data is presented. Eight parameters are derived from the OCT reflectivity profiles and their means and covariance matrices are calculated for each tissue type from a training set (48 samples) selected based on histological examination. A quadratic discrimination score is then used to assess the samples from a validation set. The algorithm results for a set of 89 breast tissue samples were correlated with the histological findings, yielding specificity and sensitivity of 0.88. If further perfected to work in real time and yield even higher ...

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    23. Swept-source parallel OCT

      We present an optical coherence tomography (OCT) system that can create a full 2D cross-sectional image of a sample within one single spectral sweep of a swept source at a frame rate of 160 fps. The unique combination of line field and swept source technologies in a Fourier domain OCT configuration achieves ultrahigh imaging speeds with a greatly simplified wavelength swept source. The system was initially tested on reflective and diffuse targets.

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    24. Real-time processing for Fourier domain optical coherence tomography using a field programmable gate array

      Teoman E. Ustun, Nicusor V. Iftimia, R. Daniel Ferguson, and Daniel X. Hammer Real-time display of processed Fourier domain optical coherence tomography (FDOCT) images is important for applications that require instant feedback of image information, for example, systems developed for rapid screening or image-guided surgery. However, the computational requirements for high-spe ... [Rev. Sci. Instrum. 79, 114301 (2008)] published Mon Nov 3, 2008.
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    25. Monitoring blood flow in the retina using a line-scanning laser ophthalmoscope

      FIELD OF THE INVENTION This invention relates generally to systems and methods for examining eyes. More particularly, the invention relates to systems and methods that employ scanned lines of light for examining eyes and monitoring blood flow in the retina.BACKGROUND OF THE INVENTIONThe retina is among the most highly vascularized and metabolically active tissues in the body. Like the central nervous system of which it is a part, it is also susceptible to ischemic injury. Degenerative diseases of
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    26. Foveal Fine Structure in Retinopathy of Prematurity: An Adaptive Optics Fourier Domain Optical Coherence Tomography Study

      purpose. To describe the fine structure of the fovea in subjects with a history of mild retinopathy of prematurity (ROP) using adaptive optics–Fourier domain optical coherence tomography (AO-FDOCT). methods. High-speed, high-resolution AO-FDOCT videos were recorded in subjects with a history of ROP (n = 5; age range, 14–26 years) and in control subjects (n = 5; age range, 18–25 years). Custom software was used to extract foveal pit depth and volume from three-dimensional (3-D) retinal maps. The thickness of retinal layers as a function of retinal eccentricity was measured manually. The retinal vasculature in the parafoveal region was assessed ...
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    1-26 of 26
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    1. (26 articles) R. Daniel Ferguson
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    Hybrid spectral domain optical coherence tomography line scanning laser ophthalmoscope High resolution multimodal clinical ophthalmic imaging system Stabilized retinal imaging with adaptive optics Preliminary evaluation of a nanotechnology-based approach for the more effective diagnosis of colon cancers Differentiation of pancreatic cysts with optical coherence tomography (OCT) imaging: an ex vivo pilot study Imaging flow dynamics in murine coronary arteries with spectral domain optical Doppler tomography Automated lamina cribrosa microstructural segmentation in optical coherence tomography scans of healthy and glaucomatous eyes In vivo dynamic characterization of the human tympanic membrane using pneumatic optical coherence tomography Negative Vessel Remodeling in Stargardt Disease Quantified with Volume-Rendered Optical Coherence Tomography Angiography Spectral Domain – Optical Coherence Tomography findings in Triple-A Syndrome – A case series from Pakistan Feasibility of microscope-integrated swept-source optical coherence tomography in canaloplasty A preliminary study of post-progressive nail-art effects on in vivo nail plate using optical coherence tomography-based intensity profiling assessment