Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 24 for “"Diffuse Optical Tomography"”.
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Developing High-Density Diffuse Optical Tomography for Neuroimaging
… function. A decade ago, there was hope that optical imaging would be able to fill this role, as it combined fMRI's ability to construct cortical maps with EEG's portable, cap-based systems. However, early optical systems had poor imaging performance, and the momentum for the technique slowed. …
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Diffuse Optical Tomography Methods for Imaging the Developing Brain
<p>Diffuse optical imaging (DOI) is a portable imaging modality that provides the ability to perform early and continuous monitoring of brain function in infants. Its methodology overcomes many of the technical and logistical challenges of performing magnetic resonance imaging (MRI) investigations …
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Investigating Cerebral Function in Neonates Using Diffuse Optical Tomography
… detect and understand brain injury in patients. Diffuse optical tomography (DOT) is a promising imaging technique that is non-invasive, portable and relatively simple to operate. In this thesis, I describe the development and design of DOT headgear for neonates and subsequently apply this in …
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Functional Imaging the Neonatal Brain with Wearable Diffuse Optical Tomography
… infant populations. Non-invasive and wearable optical brain imaging technologies may allow for the cot-side study of newborn infants in clinical settings. This has particularly important implications for preterm infants in intensive care, for whom traditional neuroimaging techniques are not …
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Application of neural networks to the reconstruction of diffuse optical tomography neuroimages
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2026-05-01
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Computational Methods for Improved Interpretation of High-Density Diffuse Optical Tomography Data
High-density diffuse optical tomography (HD-DOT) is a promising neuroimaging technique that can be used to produce three-dimensional reconstructions of brain activity. However, analysis methods applied to this data are not yet standardised, and often do not take advantage of the higher data …
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Applications of U-net to diffuse optical tomography data: Image reconstruction and superresolution
Di use optical tomography (DOT) is being investigated for effective functional brain imaging. It serves as a cheaper, less bulky and safer alternative to fMRI imaging which is the current gold standard. However, due to the complicated nature of the system, analytical reconstruction approaches begin …
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Study of the Term Neonatal Brain Injury with combined Diffuse Optical Tomography and Electroencephalography
This thesis describes the application of combined diffuse optical tomography (DOT) and electroencephalography (EEG) in the investigation of neonatal term brain injury. With hypoxic ischaemic encephalopathy (HIE) and perinatal stroke being the most frequent contributors to brain injury in the term …
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A multimodal breast cancer imaging system using coregistered dynamic diffuse optical tomography and digital breast tomosynthesis
Diffuse optical tomography (DOT) is an emerging noninvasive functional imaging method for breast cancer diagnosis and neoadjuvant chemotherapy monitoring. In particular, the multimodal approach of combining DOT with x-ray digital breast tomosynthesis (DBT) is especially synergistic as DBT prior …
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Investigating the Impact of Sleep on Early Dynamic Functional Connectivity: A High-Density Diffuse Optical Tomography Study in Term and Preterm Neonates
… in term and preterm neonates using High-Density Diffuse Optical Tomography (HD-DOT), a functional near-infrared spectroscopy (fNIRS) technology. The goal of this work was to clarify the relationship between neonatal sleep states, gestational age (GA), and functional brain development. Shedding …
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Dynamic Digital Optical Tomography for Cancer Imaging and Therapy Monitoring
Diffuse optical tomography is a non-invasive imaging technique that uses near-infrared light to create three-dimensional images of tissue. This dissertation presents the design and validation of an instrument for rapid optical imaging using digital detection techniques. In addition to a detailed …
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Enabling Biomedical Imaging Diagnostics using Optical Methods
<p>This thesis work applies optical schemes to existing biomedical imaging techniques to improve the performance of present state-of-the-art biomedical imagers, and is in two parts. In the first part, a fast and simple optical time-gate scheme for counting single photons is presented. The gate is …
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Reusing and Updating Preconditioners for Sequences of Matrices
… method, model reduction, oscillatory hydraulic tomography, diffuse optical tomography, and Helmholtz-type problems.
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Investigating the protective role of heart rate variability on the effects of aging on cerebrovascular function as estimated by optical pulse parameters
… of the cerebral arterial pulse measured with diffuse optical tomography (pulse-DOT) following long and short inter-beat intervals (IBIs). Data were obtained from a sample of 141 normal individuals (age range 25-75 years), in which both EKG and pulse-DOT (measured from the entire cortical …
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Optical Imaging Of Tissue Physiology With Exogenous Contrast Agents
… push the frontier per what one can learn from optically emitting exogenous contrast agents in living tissue. The first set of experiments concurrently measured cerebral blood flow and bothintravascular- and extravascular-tissue oxygen concentration in a rat brain during functional activation; …
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Purely optical tomography : atlas-based reconstruction of brain activation
Diffuse Optical Tomography (DOT) is a relatively new method used to image blood volume and oxygen saturation in vivo. Because of its relatively poor spatial resolution (typically no better than 1-2 cm), DOT is increasingly combined with other imaging techniques, such as MRI, fMRI and CT, which …
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Randomization for Efficient Nonlinear Parametric Inversion
… in science and engineering. We focus on diffuse optical tomography (DOT) in medical imaging. DOT aims to recover an unknown image of interest, such as the absorption coefficient in tissue to locate tumors in the body. Using a mathematical (forward) model to predict measurements given a …
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Development and Applications of Laminar Optical Tomography for In Vivo Imaging
Laminar optical tomography (LOT) is an optical imaging technique capable of making depth-resolved measurements of absorption and fluorescence contrast in scattering tissue. LOT was first demonstrated in 2004 by Hillman et al [1]. The technique combines a non-contact laser scanning geometry, similar …
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Retrieving Information from Scattered Photons in Medical Imaging
… in two specific medical imaging modalities: diffuse optical tomography (DOT) and single photon emission computed tomography (SPECT). To model the scattering of photons in biological tissue, we investigate using the Neumann-series form of the radiative transport equation (RTE). Since the …
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Robust Parameter Inversion Using Stochastic Estimates
… differential equations, such as those arising in Diffuse Optical Tomography (DOT), even the cost of repeated objective function evaluation can be overwhelming. Despite the linear (in the state variable) nature of the DOT problem, the nonlinear parameter inversion process is dominated by the …
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