Thesis (Ph. D.)--University of Oregon, 2000. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 139-151). Also available for download via the World Wide Web; free to University of Oregon users.

Thesis--M.D., University of Hong Kong, 1985.

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 197-200). Available also in a digital version from Dissertation Abstracts.

Thesis (M.S.)--University of Florida, 2002. / Title from title page of source document. Includes vita. Includes bibliographical references.

published_or_final_version / Clinical Oncology / Master / Master of Philosophy

Objective: To determine the upper airway morphometry of Chinese adults by computed tomography. Study Design: This anatomical study consisted of radiological examination of Chinese adults’ upper airway and trachea using computed tomography and image analysis with the help of post-data capture processing software. Materials and Methods: A retrospective review of sixty-five Chinese adults who underwent computed tomography of head and neck region at a regional hospital in Hong Kong was conducted. Computed tomography performed by a Philips Gemini 16? PET/CTPhilips Gemini GXL 16 PET/CT Scanner. Post-data capture processing was performed on GE Advantage Window 4.3 workstation. Measurements were made on standard or oblique reformatted orthogonal planes. Results: 65 consecutive computed tomography scans of the head and neck region of Chinese adults werereviewed. The distance between lower incisor and vocal cords was 144.0mm (±12.1 SD) in men and 124.8mm (±10.4 SD) in women. The distance between the vocal cord and cricoid ring was 21.5mm (±5.8SD) in men and 16.1mm (±6.3SD) in women. The distance between the lower incisor and cricoid ring was 165.5mm (±10.7SD) in men and 140.9 mm (±11.1SD) in women. The distance between the vocal cord and carina was 142.4mm (±12.1SD) in men and 130.4mm (±12.6SD) in women. The distance between the cricoid ring and carina was 121.0mm (±12.7SD) in men and 114.3mm (±10.2SD) in women. All these measurements showed statistically significant gender difference. In men, the anteroposterior diameter of cricoid ring was 21.8mm (±1.4SD) and the transverse diameter was 17.0mm (±1.7SD). In women the anteroposterior diameter of cricoid ring was 17.4mm (±1.9SD) and the transverse diameter was 13.4mm (±1.8SD). Both were statistically different among men and women. The anteroposterior diameter of trachea of men was 21.1mm (±2.9 SD) and the transverse diameter was 17.8mm (±2.7 SD). While the corresponding anteroposterior diameter was 16.1mm (±2.2 SD) and the transverse diameter was 15.9mm (±1.6 SD) in women with statistically significant difference. Using the Pearson correlation, body height but not age of subjects was statistically correlated with all the airway measurements Conclusion: This study reports the tracheal morphometry and dimensions in a Chinese population and their correlation with body height. Details of these measurements will aid airway management and other upper airway procedures in this population. Conclusion: This study reports the tracheal morphometry and dimensions in a Chinese population and their correlation with body height. Details of these measurements will aid airway management and other upper airway procedures in this population. Conclusion: This study reports the tracheal morphometry and dimensions in a Chinese population and their correlation with body height. Details of these measurements will aid airway management and other upper airway procedures in this population. / published_or_final_version / Anatomy / Master / Master of Medical Sciences

Optical coherence tomography (OCT) is an imaging modality analogous to ultrasound. By using the interference properties of light, one may image to micrometer resolutions using interferometric methods. Most modern systems can acquire A-scans at kHz to MHz speeds, and are capable of real-time 3D imaging. OCT has been used extensively in ophthalmology and has been used in angiography to quantify blood flow. The aim of this research has been to develop statistically optimal estimators for blood flow estimation to take advantage of these hardware advances. This is achieved through a deeper understanding of the noise characteristics of OCT. Through mathematical derivations and simulations, the noise characteristics of OCT Doppler and flow imaging were accurately modelled as additive white noise and multiplicative decorrelation noise. Decorrelation arises due to relative motion of tissue relative to the OCT region of interest and adversely affects Doppler estimation. From these models maximum likelihood estimators (MLEs) that statistically outperform the commonly used Kasai autocorrelation estimator were derived. The Cramer-Rao lower bound (CRLB), which gives the theoretical lowest estimator variance for an unbiased estimator was derived for different noise regimes. It is shown that the AWGN MLE achieves the CRLB for additive white noise dominant conditions, and the decorrelation noise MLE achieves the CRLB under more general noise conditions. The use of computational algorithms that enhance the capabilities of OCT are demonstrated. This shows that this approach for determining parametric estimators may be used in a more general medical imaging context. In addition, the use of decorrelation as a measure of speed is explored, as it is itself proportional to flow speed. / published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

Optical coherence tomography (OCT), as a newly developed imaging modality, has attracted significant attention due to its capability to obtain the cross-sectional information of biological tissues in a non-invasive way, with resolution in the range of several micrometers. The third-generation swept source OCT (SS-OCT), is superior in the speed, imaging range and signal-to-noise ratio (SNR) compared with the previous time-domain OCT (TD-OCT) and spectral domain OCT (SD-OCT), and therefore forms our research focus. In this thesis, for the first time, I investigate the deployment of Fourier domain mode-locked (FDML) swept laser by utilizing the bismuth-based erbium doper fiber (Bi-EDF) with a sweeping bandwidth of ~ 81nm achieved. Following, fiber Raman amplifier (FRA) is also investigated by employing multiple Raman pumps. The tuning range is ~111.8nm, which is much larger than the previous reported Raman pumped FDML in the 1550nm region. Imaging was performed to validate the feasibility of the proposed schemes for the SS-OCT applications, respectively. In addition to the FDML swept laser cavity design, speckle noise reduction is also of great importance in OCT, which can significantly improve the visibility of the obtained OCT images. I demonstrate two different speckle reduction methods for OCT applications, which are superior in suppressing speckle noise and reserving the one-dimensional (1D) and two-dimensional (2D) signal information, respectively. Applying the proposed wavelet domain compounding (WDC) and contourlet shrinkage method to despeckle the OCT images, the visibility of the OCT images was significantly improved, with negligible edge preservation compromise. Spectroscopic information is also of interest to many researchers as it provides additional spectroscopic contrast, which on one hand, will improve the visualization of the images, and on the other hand, will enable the classification of different tissue types and help the process of discrimination between invasive and noninvasive tumors. Compared with our previous reported work about dual-band spectroscopic OCT based on optical parametric amplifier (OPA) to generate another idler band, which will be used as the second band for dual-band spectroscopic analysis, I further extend the dual-band spectroscopic OCT to the endoscopic applications, and investigate the dual-band FDML swept laser configuration based on a custom-designed dual-channel driver to synchronize the two different wavelength bands, centered at 1310 and 1550 nm, respectively. OCT Images for different bands are captured and post-processed by coding the spectral difference in different colors. In short, in this thesis, the investigations of OCT range from system design, speckle reduction to the spectroscopic applications. All these research efforts will extend the current FDML techniques for a wide range of SS-OCT applications. These schemes may be useful in OCT swept laser source build up, speckle noise reduction, and the extension of spectroscopic analysis. / published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

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