Results 171 to 180 of about 29,054 (216)
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Doppler Velocimetry in Prolonged Pregnancy
Obstetrics & Gynecology, 1991Eighty-two patients at 287 days' gestation or longer were tested by nonstress test (NST), amnioscopy, ultrasound assessment of amniotic fluid volume, and Doppler velocimetry. Several maternal and fetal arteries were analyzed: uterine, umbilical, descending thoracic aorta, renal, and middle cerebral.
Battaglia C +4 more
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Two-color planar Doppler velocimetry
AIAA Journal, 2000Anovel two-colorapproachto planarDopplervelocimetry (PDV)isdemonstratedin a supersonice ow. Thetechnique was implemented using a frequency-doubled Nd:YAG laser and a Nd:YAG-pumped dye laser (¸ =618 nm) for illumination and a color charge-coupled device (CCD) camera for detection.
Stephen A. Arnette +3 more
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Doppler Velocimetry in Cavitating Media
ASAIO Journal, 1997A numerical model has been developed to simulate propagation of ultrasonic beams in inhomogeneous moving media. The model is based on the ray theory of propagating waves, valid in the limit of high frequencies. The resulting equations depend only on local values of the velocity field and the speed of sound. In its implementation, the model assumes that
M Z, Pindera +2 more
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Planar Doppler Velocimetry: Three-Component Velocimetry in Supersonic Jets
AIAA Journal, 1998A three-component planar Doppler velocimetry system was developed and used to make mean and instantaneous velocity measurements in a Mach 2 axisymmetric freejet. The mean measurements were in good agreement with reference laser Doppler velocimetry measurements taken in the same flowfield, whereas the instantaneous measurements were in fair agreement ...
Pamela Clancy +2 more
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Doppler velocimetry in twin pregnancy
European Journal of Obstetrics & Gynecology and Reproductive Biology, 1992The flow velocity waveform profile in the umbilical artery was measured in 50 pairs of twins during the last week before birth. A significant association was found between high resistance indicies and occurrence of late fetal heart rate decelerations; the higher the resistance, the more frequent the decelerations.
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Reproducibility of lntracranial Doppler Flow Velocimetry
Acta Paediatrica, 1986ABSTRACT. Doppler velocimetry for assessment of flow in deep cerebral arteries was investigated in 9 term and 11 preterm healthy infants. A combined range gated and continuous wave Doppler instrument was used. A satisfactory reproducibility was found with a variation coefficient of 8–10% between repeated measurements.
P, Winberg, A, Dahlström, B, Lundell
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Introduction to Doppler Velocimetry in Obstetrics
Obstetrics and Gynecology Clinics of North America, 1991Doppler velocimetry of the fetal and maternal circulation can provide important diagnostic and prognostic information. However, the precise role of this technology in screening, diagnosis, and management of perinatal complications is still evolving. This article discusses some principles of physics, techniques, clinical applications, and limitations of
S, Rotmensch, J A, Copel, J C, Hobbins
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Ultrasound Pulsed Doppler Velocimetry
Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1992Among the numerous methods used for investigating the cardiovascular system, the Doppler technique is of particular importance position. This is due to the non invasive (transcutaneous probes) or low invasive (transoesophagcal probes) approach it provides.
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