PURPOSE To develop and demonstrate a cardiac gating method for repeatable in vivo measurement of total retinal blood flow (TRBF) in humans using en face Doppler optical coherence tomography (OCT) at commercially available imaging speeds. METHODS A prototype swept-source OCT system operating at 100-kHz axial scan rate was developed and interfaced with a pulse oximeter. Using the plethysmogram ...

Dual-Doppler lidar is a powerful remote sensing technique that can accurately measure horizontal wind speeds and enable the reconstruction of two-dimensional wind fields based on measurements from two separate lidars. Previous research has provided a framework of dual-Doppler algorithms for processing both radar and lidar measurements, but their application to wake measurements has not been add...

Measurement of stroke volume by pulsed Doppler echocardiography has not been validated against a reference method in vivo. We compared Doppler systolic frequency shift integrals with electromagnetic flowmeter stroke volume in seven open-chest dogs. A pulsed Doppler echocardiographic transducer was held on the aortic arch with the sample volume in the ascending aorta. Stroke volume was varied by...

OBJECTIVE To compare cardiac output measured by the transoesophageal Doppler and thermodilution techniques. DESIGN Prospective direct comparison of paired measurements by both techniques in each patient. SETTING Intensive care unit in a cardiovascular centre. PATIENTS 65 patients after open heart surgery (mean (SD) age 53 (12) years). INTERVENTIONS Cardiac output was measured simultaneo...

Noncontact retinal blood flow measurements are performed with a Fourier domain optical coherence tomography (OCT) system using a circumpapillary double circular scan (CDCS) that scans around the optic nerve head at 3.40 mm and 3.75 mm diameters. The double concentric circles are performed 6 times consecutively over 2 sec. The CDCS scan is saved with Doppler shift information from which flow can...

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...

Thirty adult patients with aortic stenosis had Doppler echocardiography within 1 day of cardiac catheterization. Noninvasive measurement of the mean transaortic pressure gradient was calculated by applying the simplified Bernoulli equation to the continuous wave Doppler transaortic velocity recording. Stroke volume was measured noninvasively by multiplying the systolic velocity integral of flow...

The U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) Program operates several stationary and mobile aerosol and radiation measurement sites in climatologically significant regimes. At the ARM sites, millimeter wavelength profiling Doppler radars (operating at 35and 94-GHz) provide continuous high-resolution (2 sec, 45 m) 256-point FFT Doppler spectra observations of clouds an...