An FFT-based flow profiler for high-resolution in vivo investigations

Effect of vessel curvature on Doppler derived velocity profiles and fluid flow

“…The limitations of single point measurements are partially overcome by real-time multigate instruments that have been recently developed (Tortoli et al 2002;Tortoli et al 1997;Tortoli et al 1999) for measuring the actual distribution of Doppler frequencies along the US beam axis. This paper investigates the effects of vessel curvature on Doppler-derived velocity profiles and on related fluid flow estimates.…”

Spatial velocity profile changes along the cord in normal human fetuses: can these affect Doppler measurements of venous umbilical blood flow?

“…In such cases, a detailed knowledge of the hemodynamics within the insonated vessel cross-section is required. Cross-sectional information of the spatial velocity profiles may be obtained in vivo both by using sophisticated three-dimensional (3D) color 5,6 or multigate-spectral technologies 7 . Furthermore, flow velocity profiles due to complex fluid dynamics may be simulated and investigated by advanced computational model simulations 8,9 .…”

Differences between Internal Jugular Vein and Vertebral Vein Flow Examined in Real Time with the Use of Multigate Ultrasound Color Doppler

“…13 This is a matrix of power spectral densities corresponding to the simultaneously investigated depths. 14,15 The spectral profile is obtained by calculating, through the classic Fast Fourier Transform algorithm, the Doppler spectrum of 128 samples, gathered from 1 depth and by repeating the procedure over 128 or 256 consecutive depths (covering a total length of 5 cm).…”