A. James Clark School of Engineering
Permanent URI for this communityhttp://hdl.handle.net/1903/1654
The collections in this community comprise faculty research works, as well as graduate theses and dissertations.
Browse
Search Results
Item NOVEL TECHNOLOGIES AND APPLICATIONS FOR FLUORESCENT LAMINAR OPTICAL TOMOGRAPHY(2017) Tang, Qinggong Tang; Chen, Yu; Bioengineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Laminar optical tomography (LOT) is a mesoscopic three-dimensional (3D) optical imaging technique that can achieve both a resolution of 100-200 µm and a penetration depth of 2-3 mm based either on absorption or fluorescence contrast. Fluorescence laminar optical tomography (FLOT) can also provide large field-of-view (FOV) and high acquisition speed. All of these advantages make FLOT suitable for 3D depth-resolved imaging in tissue engineering, neuroscience, and oncology. In this study, by incorporating the high-dynamic-range (HDR) method widely used in digital cameras, we presented the HDR-FLOT. HDR-FLOT can moderate the limited dynamic range of the charge-coupled device-based system in FLOT and thus increase penetration depth and improve the ability to image fluorescent samples with a large concentration difference. For functional mapping of brain activities, we applied FLOT to record 3D neural activities evoked in the whisker system of mice by deflection of a single whisker in vivo. We utilized FLOT to investigate the cell viability, migration, and bone mineralization within bone tissue engineering scaffolds in situ, which allows depth-resolved molecular characterization of engineered tissues in 3D. Moreover, we investigated the feasibility of the multi-modal optical imaging approach including high-resolution optical coherence tomography (OCT) and high-sensitivity FLOT for structural and molecular imaging of colon tumors, which has demonstrated more accurate diagnosis with 88.23% (82.35%) for sensitivity (specificity) compared to either modality alone. We further applied the multi-modal imaging system to monitor the drug distribution and therapeutic effects during and after Photo-immunotherapy (PIT) in situ and in vivo, which is a novel low-side-effect targeted cancer therapy. A minimally-invasive two-channel fluorescence fiber bundle imaging system and a two-photon microscopy system combined with a micro-prism were also developed to verify the results.Item Novel Endoscope for Surgical Guidance and Functional Brain Imaging(2017) Tang, Qinggong Tang; Chen, Yu; Bioengineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Optical imaging methods have become very powerful tools in biomedical research since they can achieve both high spatial and temporal resolutions. However, due to the effects of light scattering, the penetration depth of optical imaging methods is usually limited. Gradient refractive index (GRIN) lens that are 350–2,000 μm in diameter and provide micron-scale resolution have been shown to enable minimally invasive in vivo imaging of deep tissues. Based on GRIN lens, we developed a small hand-held optical coherence tomography (OCT) forward-imaging needle device for real-time epidural anesthesia surgery guidance and demonstrated its feasibility through ex vivo and in vivo animal experiments. Besides, to access subcortical brain structures, we combined voltage-sensitive dye imaging (VSDi) with GRIN lens to image neural activities evoked in thalamic barreloids by deflection of whiskers in vivo in the whisker system of rodents.