The value of early intrapartum umbilical artery Doppler velocimetry in the prediction of fetal compromise was studied. One hundred patients were recruited into the study and fetal compromise was diagnosed by abnormal first- or second-stage fetal heart rate traces, a 5-minute Apgar score less than 7, or the development of hypoxic ischaemic encephalopathy. Fetal compromise developed in 30 patient...

Laser Doppler velocimetry is a technique used to measure linear velocity, ranging from that of exhaust gases to blood flow. A rotational analog of laser Doppler velocimetry was recently demonstrated, using a rotationally symmetric interference pattern to probe the angular velocity of a spinning object. In this work, we demonstrate the use of a diffraction-limited structured illumination pattern...

A noninvasive optical technique has been developed for imaging in vivo blood flow dynamics and vessel structure with high spatial resolution. The technique is based on optical Doppler tomography, which combines Doppler velocimetry with optical coherence tomography to measure blood flow velocity at discrete spatial locations in turbid biological tissue. Applications of this technique for monitor...

The development of Doppler Global Velocimetry as a flow diagnostic measurement sy s t em nece s s i t a t ed seve ra l innova t i ons to so l ve problems found during wind tunnel testing. These innovations ranged from ratioing a data image with a reference image to remove scattered light variations, dewarping the images to remove optical distortions, and to the use of virtual wind tunnels creat...

Objective: The purpose of this study was to determine the role of uterine artery Doppler flow velocimetry at second trimester of pregnancy in prediction of preeclampsia. Methods: This prospective study is carried out in the department of Radiodiagnosis, Krishna institute of Medical science, Karad. The study includes 220 pregnant women (primigravida) from August 2013 to September 2014 whose Uter...

We demonstrate the first in vivo gated 4D images of avian embryonic hearts by use of optical coherence tomography (OCT). We present a gated 4D dataset of an in vivo beating quail heart consisting of approximately 864,000 A-scans accumulated over multiple heartbeats. Generation of a gating trigger from a laser Doppler velocimetry (LDV) signal, collected from an outlying vitelline vessel, enabled...

Doppler optical coherence tomography (DOCT) allows simultaneous micrometer-scale resolution cross-sectional imaging of tissue structure and blood flow. We demonstrate a fiber-optic polarization-diversity-based differential phase contrast DOCT system as a method to perform self-referenced velocimetry in highly scattering media. Using this strategy, we reduced common-mode interferometer noise to ...

Amniotic fluid volume measurement forms an integral part of antenatal fetal monitoring in routine obstetric scans. Oligohydramnios has been identified as the leading cause of increased perinatal morbidity and mortality. Doppler ultrasound is extremely helpful in evaluating maternal and fetal hemodynamics in this scenario. In this study, we focus on the role of umbilical artery doppler velocimet...

An optical Doppler tomography (ODT) system that permits imaging of fluid flow velocity in highly scattering media is described. ODT combines Doppler velocimetry with the high spatial resolution of low-coherence optical interferometry to measure fluid flow velocity at discrete spatial locations. Tomographic imaging of particle flow velocity within a circular conduit submerged 1 mm below the surf...