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Transducer design and phased array beam steering are developed for a volumetric ultrasound scanner that enables the 3-D visualization of dynamic structures in real time. The authors describe the design considerations and preliminary evaluation of a high-speed, online volumetric ultrasound imaging system that uses the principles of pulse-echo, phased array(More)
Feasibility studies of autonomous robot biopsies in tissue have been conducted using real-time three-dimensional (3-D) ultrasound combined with simple thresholding algorithms. The robot first autonomously processed 3-D image volumes received from the ultrasound scanner to locate a metal rod target embedded in turkey breast tissue simulating a calcification,(More)
The National Opinion Research Center, led by a team of investigators at the University of Chicago, conducted more than 3,000 in-person interviews with a nationally representative sample of adults aged 57-85 years. Data collection included in-person questionnaire items, an extensive array of biomeasures, and a postinterview self-administered questionnaire.(More)
BACKGROUND We determined the diagnostic accuracy of the Advia Centaur TnI-Ultra assay for detecting myocardial infarction (MI) and assessing risk of adverse events in patients presenting with ischemic symptoms suggestive of acute coronary syndrome. METHODS We measured cardiac troponin I (cTnI) on admission and 6-24 h after admission (follow-up) in plasma(More)
A real time volumetric ultrasound imaging system has been developed for medical diagnosis. The scanner produces images analogous to an optical camera and supplies more information than conventional sonograms. Potential medical applications include improved anatomic visualization, tumor localization, and better assessment of cardiac function. The system uses(More)
BACKGROUND We sought to determine the diagnostic accuracy of the cardiac troponin I (cTnI) VITROS(R) Troponin I-ES assay for early detection of acute myocardial infarction (AMI) and for risk prediction of adverse events in patients with symptoms of acute coronary syndrome (ACS). METHODS cTnI was measured on admission and approximately 6 h postadmission in(More)
OBJECTIVE To characterize the safety profile of tenofovir disoproxil fumarate (DF) for the treatment of HIV infection in adults over the first 4 years of use. METHODS A tenofovir DF expanded access program (EAP) was initiated in 2001; safety data were examined from this program and from the manufacturer's database, which contained reports of all(More)
The data acquisition rate in medical ultrasonic imaging devices is limited by the acoustic propagation velocity in the tissues. Typically in such machines the image lines are produced sequentially one line per transmitted pulse. A parallel processing scheme has been implemented which enables the data acquisition rate to increase by a factor of four through(More)
Refinements to previous analyses of the natural correlation lengths within simple images and between images to be compounded are presented. Comparison of theoretical and experimental results show very good agreement for the case of Rayleigh scattering media: the correlation length within a simple image is comparable to the resolution cell size; the(More)