William A. Armstrong

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OBJECTIVE The purpose of our study was to compare aortic valve area and calcification between CT and echocardiography. MATERIALS AND METHODS We performed retrospective evaluation of 80 consecutive patients with aortic stenosis (AS) who underwent ECG-gated 64-MDCT and transesophageal echocardiography (TEE). Valve planimetry was feasible in 80 patients with(More)
Guidelines on the provision of manual wheelchairs in less-resourced settings. The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or(More)
PURPOSE The Center for International Rehabilitation (CIR) developed a wheelchair provision strategy that combines central fabrication with regional distribution and local service provision by trained practitioners. A field study was initiated in Kabul, Afghanistan to evaluate this plan. METHOD The CIR-Whirlwind Wheelchair (study wheelchair) is an adult(More)
A robust filter-based approach is proposed for wireless sensor networks for detecting contours of a signal distribution over a 2-dimensional region. The motivation for contour detection is derived from applications where the spatial distribution of a signal (such as temperature, soil moisture level, etc.) is to be determined over a large region with minimum(More)
This paper is a tribute to an unsung accountant, economist and engineer, who had a clear understanding of modern concepts in accounting and finance, such as discounted cash flows, risk-adjusted discount rates and Net Present Value (NPV), which are usually considered to be twentieth century developments. He applied these in practice from 1850 but, until now,(More)
DEDICATION To my mother ii ACKNOWLEDGEMENTS Many mentors and colleagues contributed to my work summarized in this dissertation during the years of my studies. I would like to thank particularly to my advisor professor, Dr. Shaul Hestrin to give me the opportunity to work on this project, providing me an environment for developing my scientific skills and(More)