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...

A scheme for molecular tagging velocimetry is presented that can be used in air flows without any kind of seeding. The method is based on the local and instantaneous creation of nitric oxide (NO) molecules from N(2) and O(2) in the waist region of a focused ArF excimer laser beam. This NO distribution is advected by the flow and can be visualized any time later by laser-induced fluorescence in ...

We developed a novel method of measurement of the dynamic light scattering phase function of particles utilizing laser Doppler technique. We show the theoretical background, validation carried out on Monte Carlo data and proposition of measurement setup. OCIS codes: (290.5820) Scattering measurements; (170.3660) Light propagation in tissues, (170.5280) Photon migration, (170.3340) Laser Doppler...

A VECTOR SCANNING PROCESSING TECHNIQIJE FOR PULSED LASER VELOCIMETRY Mark P. Wernet National Aeronautics and Space Administration Lewis Research Center Cleveland, Ohio 4113.5 and Robert V. Edwards Case Western Reserve University Dept. of Chemical Engineering Cleveland, Ohio 44106 by Pulsed laser sheet velocimetry yields non-intrusive measurements of two-dimensional velocity vectors across an ex...

REFERENCES AND LINKS [1] H. T. Yura and S. G. Hanson, “Optical Beam Wave Propagation through Complex Optical Systems.” J. Opt. Soc. Am. A. 4, 10, 1931-1948 (1987). [2] H. Kogelnik and T. Li, "Laser beams and resonators," Appl. Opt. 5, 1550-1567 (1966). [3] H. T. Yura, B. Rose and S. G. Hanson, “Dynamic laser speckle in complex ABCD-optical systems.” J. Opt. Soc. Am. A. 15, 1160-1166 (1998). [4]...

Laser Doppler velocimetry is a newly available technique for the continuous and non-invasive measurement of capillary perfusion. The technique is presented and preliminary results of its use in the evaluation of amputation levels in 16 patients discussed.

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...

Our recent work [1] theoretically revealed that speckles can be formed when nanofluids containing a modest volume fraction of nanoparticles are illuminated by a monochromatic laser beam. This paper focuses on the key issues, including the experimental setup, the particle volume fraction of the nanofluid, the flow velocity of the nanofluid and the diameter of the pipe, in measuring the velocitie...

We present the photoacoustic imaging velocimetry (PAIV) method for flow-field measurement based on a linear transducer array. The PAIV method is realized by using a Q-switched pulsed laser, a linear transducer array, a parallel data-acquisition equipment and dynamic focusing reconstruction. Tracers used to track liquid flow field were real-timely detected, two-dimensional (2-D) flow visualizati...