Title :
Wavefront backpropagation and focus correction [medical ultrasonics]
fDate :
31 Oct-3 Nov 1993
Abstract :
Wavefront distortion encountered in transmission through human abdominal wall is modelled as the result of propagation in a uniform medium after passing through a phase screen. To compensate for the waveform distortion developed during propagation, wavefront backpropagation is employed. The position of the equivalent phase screen is identified by maximization of a waveform similarity factor. The wavefront at that position is then time-shift compensated using arrival time estimates obtained by a reference waveform method. The compensated wavefront is subsequently focussed. The results indicate that wavefront backpropagation reduces the waveform distortion, and that the backpropagated and time-shift compensated wavefront produces a better focus than that obtained by time-shift compensation in the aperture
Keywords :
biomedical ultrasonics; focusing; ultrasonic propagation; abdominal wall; arrival time; focus correction; human; medical ultrasonics; reference waveform method; time-shift compensation; waveform distortion; wavefront backpropagation; Abdomen; Apertures; Backpropagation; Distortion measurement; Fourier transforms; Phase distortion; Propagation delay; Shape measurement; Time measurement; Ultrasonic variables measurement;
Conference_Titel :
Ultrasonics Symposium, 1993. Proceedings., IEEE 1993
Conference_Location :
Baltimore, MD
Print_ISBN :
0-7803-2012-3
DOI :
10.1109/ULTSYM.1993.339591