Two schemes for processing signals obtained from the Doppler global velocimeter are described. The analog approach is a simple, real time method for obtaining an RS -170 video signal containing the normalized intensity image. Pseudo colors are added using a monochromatic frame grabber producing a standard NTSC video signal that can be monitored and/or recorded. The digita l approach is more com...

Transparent stereolithographic rapid prototyping (RP) technology has already demonstrated in literature to be a practical model construction tool for optical flow measurements such as digital particle image velocimetry (DPIV), laser doppler velocimetry (LDV), and flow visualization. Here, we employ recently available transparent RP resins and eliminate time-consuming casting and chemical curing...

UNLABELLED Doppler ultrasound is a non-invasive method for evaluating vascularization and is widely used in clinical practice. Gestational trophoblastic neoplasia includes a group of highly vascularized malignancies derived from placental cells. This review summarizes data found in the literature regarding the applications of Doppler ultrasound in managing patients with gestational trophoblasti...

Abstract Background: Epidemiologic studies have shown the relationship of maternal hemoglobin level and abnormal findings in uterine Doppler sonography with pregnancy- related complications. In this study, we evaluated the relationship of uterine artery Doppler velocimetry findings and hemoglobin level with the outcomes of pregnancy in women with preeclampsi...

A method is described for the measurement of basilar membrane (BM) vibration velocimeter (LDV). The instrumentation was coupled to a compound microscope which served to visualize reflective glass microbeads placed on the BM. The laser beam of the LDV was focused in the microscope object plane and positioned over the reflective bead. We show examples of frequency tuning curves and displacement i...

We report on experiments on the effects of air bubbles on ultrasound velocity measurements in fluids. We used an acoustic Doppler velocimeter system for measuring the three velocity components in a single point and an acoustic Doppler velocimetry profiler system for measuring axial velocity in several points along the beam. The results suggest that both systems essentially measure the velocity ...

Photon Doppler velocimetry (PDV) has made the transition among many experimental groups from being a new diagnostic to being routinely fielded as a means of obtaining velocity data in high-speed test applications. Indeed, research groups both within and outside of the shock physics community have taken note of PDV’s robust, high-performance measurement capabilities. As PDV serves as the primary...

The development of data processing techniques and algorithms for Doppler Global Velocimetry is presented. The discussion begins with the fundamental calculation of the velocity dependent transfer function of Iodine vapor, and proceeds through laboratory and wind tunnel investigations to develop insight into the physics of the technique. The knowledge gained through this process provided the bas...

While photonic Doppler velocimetry (PDV) is becoming a common diagnostic in dynamic compression research, its limiting accuracy and precision are not well understood. Velocity resolution is known to be inversely proportional to the time resolution, but resolution estimates differ by one to two orders of magnitude. Furthermore, resolution varies with the number of recorded signals and how these ...

A miniaturized sensor head for the optical measurement of velocities of fluids based on laser Doppler velocimetry is demonstrated. Holographic optical elements mounted on a glass substrate are used for beam splitting and deflection. Volume holograms in dichromated gelatin exhibit good optical efficiency (75% transmission of a cascade of two holographic optical elements). With diffractive device...