Results 181 to 190 of about 10,642 (230)

Doppler velocimetry in twin pregnancy

European Journal of Obstetrics & Gynecology and Reproductive Biology, 1992
The 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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Umbilical artery doppler velocimetry—an update

Seminars in Perinatology, 2001
Doppler ultrasonography was introduced into clinical obstetric practice over 20 years ago. It is also accepted that a variety of common obstetrical complications such as preeclampsia and intrauterine growth restriction have their origin in abnormal development of the placental vasculature and this could be reflected in abnormal Doppler velocimetry ...
M Y, Divon, A, Ferber
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Planar Doppler Velocimetry: Three-Component Velocimetry in Supersonic Jets

AIAA Journal, 1998
A 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, Mo Samimy, William Erskine   +2 more
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Laser Doppler Velocimetry: Experimental Study

Applied Optics, 1974
An experimental study on the general characteristics of the three different optical arrangements, namely, local-oscillator heterodyne, differential heterodyne, and symmetric heterodyne, is given. Both rotating Mylar disk and steady-state rotating flow are used to generate a uniform particle velocity or flow velocity.
C P, Wang, D, Snyder
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Laser Doppler velocimetry

Journal of Quantitative Spectroscopy and Radiative Transfer, 1988
Abstract Because it uses light scattering, Doppler shift, and optical heterodyne, laser Doppler velocimetry is an extremely powerful diagnostic technique for the measurement of flow velocity components. Its basic principles, optical arrangements, signal processing techniques, and applications are discussed as well as its advantages, disadvantages ...
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Reproducibility of lntracranial Doppler Flow Velocimetry

Acta Paediatrica, 1986
ABSTRACT. 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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Doppler velocimetry in the evaluation of fetal hypoxia

Journal of Perinatal Medicine, 2001
Knowledge of fetal hemodynamic physiology has developed enormously during the last two decades due to Doppler ultrasound. Some of this knowledge has been utilized for routine surveillance of high-risk pregnancies. The prediction of fetal hypoxia before the development of life lasting sequel is of major importance, especially in the very premature case ...
S, Gudmundsson, M, Dubiel
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Multiple-line laser Doppler velocimetry

Applied Optics, 1988
A laser Doppler velocimetry diagnostic fitting high-strain rate motion of solids as in shock wave experiments by now requires a single-mode laser. We have worked out a new method of increasing by 1 order of magnitude the luminosity of such a diagnostic.
S, Gidon, G, Behar
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Doppler velocimetry of fetal pericardial fluid

International Journal of Gynecology & Obstetrics, 2009
AbstractObjectiveTo investigate the flow of normal fetal pericardial fluid (PF) with increasing gestational age using Doppler velocimetry.MethodNinety‐five fetuses between 18 and 37 weeks of gestation with PF within the normal range were studied. PF was measured in 4‐chamber view using M‐mode or real‐time ultrasound.
Orapun, Aoekkasit, Boonchai, Uerpairojkit   +1 more
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Burst-correlation laser Doppler velocimetry

Optics Letters, 1983
The first continuous real-time burst-correlation laser velocimetry results obtained to our knowledge are reported. Measurements of turbulence power spectra and velocity-correlation functions with photon-correlation techniques are demonstrated.
R G, Brown, R, Jones
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