A laser Doppler velocimetry bench adapted for measuring acoustic particle velocities is used to measure sinusoidal structural velocities in order to assess the performance of two signal processing techniques, one available commercially and the other being developed in our laboratory. Considering a sinusoidal excitation signal of the vibrating structure, both techniques use frequency demodulatio...

In this paper, an experimental investigation was carried out to study the turbulent flows and flow characteristics through sloping and adversely sloping rectangular culverts in a rectangular channel of constant width using Laser Doppler Velocimetry (LDV). Also, experimental study was carried out to investigate the characteristics of the hydraulic jump occurring in a sloping and adversely slopin...

In this paper we describe a method to measure fluid flow fields that we call Multi-Point Laser Doppler Anemometry (MPLDA). Like Doppler Global Velocimetry (DGV) and single point Laser Doppler Anemometry (LDA), the technique derives information from the Doppler shift observed when light is scattered from a moving particle and exploits the advantages of these techniques. The method retains the el...

Introduction: The incidence of intrauterine growth restriction is approximately 10%. The management depends upon diagnosis, follow up and timely delivery of the fetus. Material & Methods: Prospective cohort study was conducted at a zonal hospital from Oct 2014 to Aug 2016 on 60 women with clinical suspicion of FGR. After confirming FGR with ultrasound, these patients were followed with umbilica...

Two frequency planar Doppler Velocimetry (2ν-PDV) is a modification of the Planar Doppler Velocimetry (PDV) method that allows velocity measurements to be made, quickly and non intrusively, across a plane defined by a laser light sheet. In 2ν-PDV the flow is illuminated sequentially with two optical frequencies, separated by about 700MHz. A single CCD viewing through an iodine absorption cell i...

Administration of low doses of Escherichia coli endotoxin [a lipopolysaccharide (LPS)] to humans enables the study of inflammatory mechanisms. The purpose of the present study was to investigate whether the blue-field entoptic technique may be used to quantify the increase in circulating leukocytes in the ocular microvasculature after LPS infusion. In addition, combined laser Doppler velocimetr...

Background. The transient effects of epidural bupivacaine 0.25–0.5% on the Doppler velocimetry of umbilical and uterine arteries had been reported, but the effects of continuous lower dose epidural bupivacaine (0.05–0.1%) infusion for labour analgesia have never been reported. In this study, we evaluated the effects of continuous epidural bupivacaine 0.075% on the Doppler velocimetry of uterine...

Objectives. This study investigated the proximal centerline flow convergence region simultaneously by both color Doppler and laser Doppler velocimetry. Background. Although numerous investigations have been performed to test the flow convergence method, to our knowledge there has yet been no experimental study using reference standard velocimetric techniques to define precisely the hydrodynamic...

OBJECTIVES To reanalyze randomized controlled trials on the use of umbilical artery Doppler velocimetry in high-risk pregnancies and determine which high-risk pregnancies benefit from the use of Doppler velocimetry. METHODS Searching Medline, the Cochrane Library and Embase we found 13 randomized controlled trials on the use of Doppler velocimetry in high-risk pregnancies. Of these, six inclu...

The response of the retinal circulation to an acute elevation in systemic blood pressure was studied in three healthy normotensive volunteers using the noninvasive laser Doppler velocimetry (LDV) technique combined with retinal vessel size measurements. Isometric exercise was employed to induce the acute rise in arterial pressure. There was no detectable change in retinal blood flow until the m...