1. Articles in category: Student Theses

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    1. OPTICAL COHERENCE ELASTOGRAPHIC AND TOMOGRAPHIC MICROSCOPY FOR RESOLUTION-ENHANCED MICROMECHANICAL AND STRUCTURAL IMAGING OF BIOLOGICAL SYSTEMS

      OPTICAL COHERENCE ELASTOGRAPHIC AND TOMOGRAPHIC MICROSCOPY FOR RESOLUTION-ENHANCED MICROMECHANICAL AND STRUCTURAL IMAGING OF BIOLOGICAL SYSTEMS

      Optical microscopy has had a revolutionary impact in the biomedical sciences. Among other modalities, optical coherence tomography (OCT) offers a unique capability for label-free structural imaging of biological systems at cellular resolution over millimeter-scale volumetric field-of-view. The rapidly growing field of mechanobiology has presented immense opportunities for not only structural microscopy, but also functional imaging of biomechanical properties with emerging optical elastography techniques. Importantly, attention has been given to the role of biomechanical interactions between cells and the extracellular matrix (ECM) in various biological processes, including onset and progression of cancer, stem cell differentiation, morphogenesis, and wound healing. Although a ...

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    2. The Use of Optical Coherence Tomography to Asscess Water Transport Through The Urothelium of The Porcine Bladder

      The Use of Optical Coherence Tomography to Asscess Water Transport Through The Urothelium of The Porcine Bladder

      Recent reports pointed out that the urothelium was a permeable membrane and had some sensory and signaling functions. The aquaporins expression has been found in the urothelium, implicit water transport through the urothelium. However, this process has never been observed directly. This study aims to better understand water transport through urothelium and how sodium chloride affects urothelial integrity during the water transport process. We hypothesize that optical coherence tomography could be used to monitor the dynamical water transport process through the porcine bladder urothelium. The water transport process could be affected by the sodium chloride concentration over the urothelium. And ...

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    3. Optical coherence tomography in multiple sclerosis: contributions to understanding its use in clinical practice

      Optical coherence tomography in multiple sclerosis: contributions to understanding its use in clinical practice

      Multiple sclerosis (MS) is a chronic disease of the central nervous system (CNS) affecting more than two million people worldwide. The disease is characterised by inflammation in the CNS (leading to episodes of focal neurological dysfunction, i.e. relapses) and neurodegeneration (leading to progressive and permanent disability). Depending on the localisation of the CNS damage, patients exhibit a wide range of symptoms including muscle weakness, sensory disturbances, problems with coordination, fatigue and cognitive impairment. Visual symptoms are common as well, with more dan 50% of MS patients experiencing one or more episodes of optic neuritis (ON) during the course of ...

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    4. Evaluating Severity of Microbial Keratitis Using Optical Coherence Tomography

      Evaluating Severity of Microbial Keratitis Using Optical Coherence Tomography

      Microbial keratitis (MK) is an infection of the cornea caused a variety of pathogens that can lead to significant visual loss. The current diagnosis relies on clinical examination and microbiological testing. New in-vivo imaging techniques are now available that can assist the diagnosis and follow the clinical course of this disease. Using optical coherence tomography (OCT) it is possible to obtain high resolution imaging for the cornea. The purpose of this thesis is to demonstrate a link between the latest OCT technology and clinical outcomes by using a severity index scoring tool. A prospective study was undertaken including 68 eyes ...

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    5. Photonic integrated circuits for optical coherence tomography (Thesis)

      Photonic integrated circuits for optical coherence tomography (Thesis)

      Optical coherence tomography (OCT) is a well established 3D cross-sectional imaging method for retinal diagnostics. However, the method is largely limited to a clinical setting, with more widespread utilization being hindered by both the size and the cost of current systems. A reduction of both would significantly increase the potential application range, especially, for point of care diagnostics. One approach to reduce the size and cost is the utilization of photonic integrated circuits (PICs) to substitute bulk and/or fiber optic components used in conventional OCT systems. PICs provide optical systems in a chip-scale format, similar to integrated circuits (ICs ...

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    6. Invasive Coronary Artery Imaging Using Optical Coherence Tomography: A Cost-effectiveness and Implementation Process Analysisg (Thesis)

      Invasive Coronary Artery Imaging Using Optical Coherence Tomography: A Cost-effectiveness and Implementation Process Analysisg (Thesis)

      The aim of this project was the implementation of optical coherence tomography (OCT), an invasive intracoronary imaging (ICI) tool used for the visualization of coronary arteries. The implementation was performed in a structured manner by: (1) A literature review into the current applications of OCT in relation to current standards; (2) A thesis feasibility study into clinical practices, professional views and other processes regarding ICI; (3) A Master’s thesis including a cost-effectiveness analysis (CEA) and the actual implementation of OCT at the department. The project started with a literature review about the current applications of OCT in relation to ...

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    7. DEVELOPMENT OF PHASE DECORRELATION OPTICAL COHERENCE TOMOGRAPHY FOR ASSESSMENT OF THE OCULAR LENS AND CORNEA

      DEVELOPMENT OF PHASE DECORRELATION OPTICAL COHERENCE TOMOGRAPHY FOR ASSESSMENT OF THE OCULAR LENS AND CORNEA

      The human ocular system is tightly maintained in order to sharply focus images onto the retina. Our understanding of the ocular system has benefited from the study of biomechanical phenomena. For instance, the field has begun to understand a range of diseases as biomechanical in origin – such as keratoconus, glaucoma, and myopia. This mechanical understanding of disease has led to the development of new treatments, primarily crosslinking, which directly address the mechanical deficiency and have generally proved to be highly effective. Keratoconus, which until recently could only be treated through contact lenses and corneal transplants, can now be treated relatively ...

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    8. Multidimensional Data Processing for Optical Coherence Tomography Imaging (Thesis)

      Multidimensional Data Processing for Optical Coherence Tomography Imaging (Thesis)

      Optical Coherence Tomography (OCT) is a medical imaging technique which distinguishes itself by acquiring microscopic resolution images in-vivo at millimeter scale fields of view. The resulting in images are not only high-resolution, but often multi-dimensional to capture 3-D biological structures or temporal processes. The nature of multi-dimensional data presents a unique set of challenges to the OCT user that include acquiring, storing, and handling very large datasets, visualizing and understanding the data, and processing and analyzing the data. In this dissertation, three of these challenges are explored in depth: sub-resolution temporal analysis, 3-D modeling of fiber structures, and compressed sensing ...

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    9. Computational Methods for Image Acquisition and Analysis with Applications in Optical Coherence Tomography

      Computational Methods for Image Acquisition and Analysis with Applications in Optical Coherence Tomography

      The computational approach to image acquisition and analysis plays an important role in medical imaging and optical coherence tomography (OCT). This thesis is dedicated to the development and evaluation of algorithmic solutions for better image acquisition and analysis with a focus on OCT retinal imaging. For image acquisition, we first developed, implemented, and systematically evaluated a compressive sensing approach for image/signal acquisition for single-pixel camera architectures and an OCT system. Our evaluation outcome provides a detailed insight into implementing compressive data acquisition of those imaging systems. We further proposed a convolutional neural network model, LSHR-Net, as the first deep-learning ...

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    10. Towards estimation of optical and structural ophthalmic properties based on optical coherence tomography

      Towards estimation of optical and structural ophthalmic properties based on optical coherence tomography

      Early diagnosis of retinal diseases such as glaucoma will benefit from unbiased an precise estimation of both optical and structural properties of the RNFL as they provide a better understanding of the tissue characteristics. The main objective of this thesis was first to improve the estimation of the attenuation coefficients of layered samples and, second, to estimate the structural properties of RNFL. Unbiased estimation of optical tissue properties such as the attenuation coefficient require a model of the recorded OCT signal. To study the characteristics of the OCT signal, in Chapter 2, two simulation methods were presented for homogeneous samples ...

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    11. Optical coherence tomography (OCT) and irreversible electroporation (IRE) in the diagnosis and treatment of renal masses

      Optical coherence tomography (OCT) and irreversible electroporation (IRE) in the diagnosis and treatment of renal masses

      The first aim of this thesis is to investigate the diagnostic value of needle-based, percutaneous optical coherence tomography (OCT) in the differentiation of renal masses. Secondly, the feasibility and safety of percutaneous, irreversible electroporation (IRE) are assessed for the treatment of SRMs.

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    12. Multidimensional Data Processing for Optical Coherence Tomography Imaging (Thesis)

      Multidimensional Data Processing for Optical Coherence Tomography Imaging (Thesis)

      Optical Coherence Tomography (OCT) is a medical imaging technique which distinguishes itself by acquiring microscopic resolution images in-vivo at millimeter scale fields of view. The resulting in images are not only high-resolution, but often multi-dimensional to capture 3-D biological structures or temporal processes. The nature of multi-dimensional data presents a unique set of challenges to the OCT user that include acquiring, storing, and handling very large datasets, visualizing and understanding the data, and processing and analyzing the data. In this dissertation, three of these challenges are explored in depth: sub-resolution temporal analysis, 3-D modeling of fiber structures, and compressed sensing ...

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    13. The use of optical coherence tomography to enhance surgical margin assessment for canine mast cell tumors (Thesis)

      The use of optical coherence tomography to enhance surgical margin assessment for canine mast cell tumors (Thesis)

      Experiment 1: Objective: To document the appearance of artifacts created by commonly encountered surgical conditions and instrumentation on optical coherence tomography (OCT) and compare these findings with histopathology. Study design: Ex vivo study Animals: 5 canine cadavers Methods: Skin, subcutaneous fat, skeletal muscle, and fascia samples were obtained from fresh canine cadavers. Blood pooling, hemostatic crushing, scalpel blade cut, monopolar electrosurgery, bipolar vessel sealing device and ultrasonic energy surgical artifacts were induced on each tissue type. Each specimen was interrogated with OCT and subsequently histologically processed. Results: The majority of surgical instrumentation used for tumor excision created a high-scattering region ...

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    14. Automated Algorithm for Optical Coherence Tomography (OCT) Images of 3D Spheroids (Thesis)

      Automated Algorithm for Optical Coherence Tomography (OCT) Images of 3D Spheroids (Thesis)

      The application of three-dimensional (3D) tumor spheroids has been expanding due to their ability to closely mimic several features of solid tumors such as their cellular heterogeneity/organization and growth kinetics. Optical Coherence Tomography (OCT) system has been utilized to characterize 3D morphological and physiological information of multicellular tumor spheroids. In order to characterize and analyze the results of 3D OCT spheroid datasets, there is a need to develop an automated algorithm with high accuracy that can calculate the volume of a tumor spheroid and its necrotic tissues. The developed automated algorithm can automatically detect the margin of the 3D ...

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    15. Characterization Of The Macular Choriocapillaris In Dry Age-Related Macular Degeneration Using Swept-Source Optical Coherence Tomography Angiography (Thesis)

      Characterization Of The Macular Choriocapillaris In Dry Age-Related Macular Degeneration Using Swept-Source Optical Coherence Tomography Angiography (Thesis)

      The purpose of this study was to characterize further, using swept-source (SS-) optical coherence tomography angiography (OCTA), the relationship between dry age-related macular degeneration (AMD) and the macular choriocapillaris (CC), which may have pathophysiologic and therapeutic implications. It included (1) a topographic analysis to determine if there is a significant relationship between dry AMD stage and macular CC perfusion, and (2) an investigation of the predictive value of macular CC perfusion with respect to geographic atrophy (GA) growth rate. Study design was retrospective and cross-sectional. A database of 6x6 mm fovea-centered swept-source OCTA images of the CC from eyes with ...

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      Mentions: Yale University
    16. High-speed Time-stretch Optical Coherence Tomography (Thesis)

      High-speed Time-stretch Optical Coherence Tomography (Thesis)

      Supercontinuum sources have great potential in optical coherence tomography due to their ultrabroad spectra, which provide ultrahigh resolution images. High intensity noise of conventional supercontinuum sources, however, has been the limiting factor of widespread adoption, but the emergence of low noise supercontinuum sources promise to change this. In this thesis, both types of supercontinuum sources are tested in a spectrometer-based optical coherence tomography setup, where it is found that the low noise supercontinuum is able to produce the shot noise limited images, a feat that is not replicated by the conventional supercontinuum. Furthermore, the two types of supercontinuum sources are ...

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    17. Image-guidance in ophthalmic surgery using optical coherence tomography (Thesis)

      Image-guidance in ophthalmic surgery using optical coherence tomography (Thesis)

      Ophthalmic surgery involves manipulation of layered tissue structures on milli- to micrometer scales. Traditional surgical microscopes provide a two-dimensional view of the surgical field with limited depth perception which precludes accurate depth-resolved visualization of surgically-induced tissue morphology. Optical coherence tomography (OCT) enables non-contact exogenous contrast-free imaging of subsurface tissue microstructures, and is currently the gold standard for ophthalmic clinical diagnostics. Over the last decade, translation of OCT technologies to applications in surgical planning and guidance in ophthalmology has been an active area of research and commercialization. Clinical studies confirmed benefits of intraoperative OCT including verification that surgical goals have been ...

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    18. Studying Cerebral Blood Flow in Mouse Cortex with Optical Microangiography (Thesis)

      Studying Cerebral Blood Flow in Mouse Cortex with Optical Microangiography (Thesis)

      Optical coherence tomography (OCT) is a non-contact three-dimensional (3D) imaging modality which enables fast in vivo volumetric visualization of internal structures of biological tissues with high resolution. In this thesis, first, the application of OCT advanced extension - optical microangiography (OMAG) - was used to reveal the temporal profile of hemodynamic response to neural activation and the variation of depth-resolved blood flow changes in mouse cerebral cortex. The results showed that the largest hemodynamic response occurred in cortical layer IV. Second, OMAG and Doppler OMAG (DOMAG) techniques were applied to quantitatively evaluate the anesthesia effect on cerebral vessel morphology and blood flow ...

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    19. Traction force optical coherence microscopy: a new method to study the dynamic mechanical behavior of cells and multicellular collectives within scattering media (Thesis)

      Traction force optical coherence microscopy: a new method to study the dynamic mechanical behavior of cells and multicellular collectives within scattering media (Thesis)

      Mechanobiology is a prominent research field which seeks to elucidate the role of physical forces and mechanical interactions throughout various biological processes, including morphogenesis, wound healing, and cancer metastasis, among others. Traction force microscopy (TFM) is an important family of experimental techniques used by mechanobiologists to study and quantify the forces that cells exert upon their surroundings. Recent years have seen a growing demand for TFM methods capable of studying the dynamic, 3D, and collective behaviors of cells embedded within optically scattering media. However, traditional imaging modalities for TFM (e.g., confocal microscopy) do not currently allow researchers to satisfy ...

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    20. Deep learning for quantitative motion tracking based on optical coherence tomography (Thesis)

      Deep learning for quantitative motion tracking based on optical coherence tomography (Thesis)

      Optical coherence tomography (OCT) is a cross-sectional imaging modality based on low coherence light interferometry. OCT has been widely used in diagnostic ophthalmology and has found applications in other biomedical fields such as cancer detection and surgical guidance. In the Laboratory of Biophotonics Imaging and Sensing at New Jersey Institute of Technology, we developed a unique needle OCT imager based on a single fiber probe for breast cancer imaging. The needle OCT imager with sub-millimeter diameter can be inserted into tissue for minimally invasive in situ breast imaging. OCT imaging provides spatial resolution similar to histology and has the potential ...

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    21. Optical coherence tomography vs fundus photography in detecting macular edema in subjects with type 2 diabetes (Thesis)

      Optical coherence tomography vs fundus photography in detecting macular edema in subjects with type 2 diabetes (Thesis)

      Introduction The screening of diabetic retinopathy has been relied on fundus photography but since it is 2-dimensional, it is difficult to identify diabetic macular edema (DME), which is the most feared ocular complication related to diabetes. Optical coherence tomography (OCT) has been shown to be a useful tool in detecting and monitoring DME. The main objective of this study was to screen people with type 2 diabetes and find out how many patients have current diabetic macular edema and to compare different screening equipment by means of fundus photography and OCT when evaluating macular edema. Method The sample of this ...

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    22. Measuring 3D Optic Nerve Head Deformations using Digital Volume Correlation of in vivo Optical Coherence Tomography Data (Thesis)

      Measuring 3D Optic Nerve Head Deformations using Digital Volume Correlation of in vivo Optical Coherence Tomography Data (Thesis)

      The optic nerve head (ONH), located in the back of the eye, is a critical site in understanding the pathophysiology of glaucoma. However, longitudinal changes of the ONH as disease develops have not been well characterized. Our goal was to develop an improved tool to quantify these changes in an in vivo monkey model of glaucoma. Longitudinal spectral-domain optical coherence tomography (OCT) imaging of the ONH was performed every other week under manometric intraocular pressure (IOP) control (10 mmHg) in a monkey during baseline and after induction of unilateral experimental glaucoma. We developed a computational pipeline that applied digital volume ...

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    23. Optical coherence tomography for characterization of nanocomposite materials (Thesis)

      Optical coherence tomography for characterization of nanocomposite materials (Thesis)

      Nanocomposite materials play an increasingly important role in various application areas, be it in an industrial, medical or everyday environment. The unique properties of nanocomposites go beyond those of conventional composite materials. Because nanoparticles have a high surface-to-volume ratio such as carbon nanotubes, they can reinforce an embedding polymer host matrix mechanically, or they enhance the electrical material conductivity. A major challenge in the development of nanoparticles and nanocomposites is the control of particle size and shape, and of the uniform dispersion of nanoparticles in the host material. Conventional characterization techniques lack either resolution, or can only inspect details of ...

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