Title :
Velocity and acceleration estimation employing nonuniform sampling
Author :
Benner, L. ; Wilkening, W. ; Ermert, H.
Author_Institution :
Fac. of Electr. Eng., Ruhr-Univ., Bochum, Germany
Abstract :
Our group has previously proposed nonuniform sampling for flow velocity estimation. Standard pulsed wave Doppler (PWD) systems acquire an ensemble of N echoes per beam line at a constant pulse repetition frequency fprf. The total time span determines the velocity resolution, and fprf the unambiguous velocity range. The ensemble size N is by approximation inversely proportional to the frame rate, assuming that the system performs interleaving. If sampling intervals are chosen nonuniformely, the total time span can be increased, while keeping N and the shortest sampling interval constant. In this example velocity range and frame rate are unchanged, and measurement accuracy for low flow velocities is gained at the expense of measurement accuracy for high flow velocities. The extended time span makes the flow estimation susceptible to effects of acceleration and decorrelation. Thus, we have refined the flow estimation algorithms by taking into account both effects.
Keywords :
Doppler measurement; acceleration measurement; acoustic wave velocity measurement; blood flow measurement; decorrelation; signal sampling; PWD systems; acceleration estimation; decorrelation; flow velocity estimation; measurement accuracy; nonuniform sampling; pulsed wave Doppler systems; sampling interval; Acceleration; Biomedical engineering; Ferroelectric materials; Interleaved codes; Lab-on-a-chip; Linear regression; Nonuniform sampling; Scattering; Signal resolution; Ultrasonics, ferroelectrics, and frequency control;
Conference_Titel :
Ultrasonics Symposium, 2004 IEEE
Print_ISBN :
0-7803-8412-1
DOI :
10.1109/ULTSYM.2004.1418253