Abstract Nonlinear propagation of focused ultrasound in layered biological tissues is theoretically studied by using the angular spectrum approach (ASA), in which an acoustic wave is decomposed into its angular spectrum, and the distribution of nonlinear acoustic fields is calculated in arbitrary planes normal to the acoustic axis. Several biological tissues are used as specimens inserted into the focusing region illuminated by a focused piston source. The second harmonic components within or beyond the biological specimens are numerically calculated. Validity of the theoretical model is examined by measurements. This approach employing the fast Fourier transformation gives a clear visualization of the focused ultrasound, which is helpful for nonlinear ultrasonic imaging.
Received: 14 December 2004
Revised: 14 January 2005
Accepted manuscript online:
PACS:
87.50.Y-
(Biological effects of acoustic and ultrasonic energy)
(Ultrasonics, quantum acoustics, and physical effects of sound)
Fund: Project supported by the National Natural Science Foundation of China (Grant No 10204014).
Cite this article:
Zhu Xiao-Feng (朱晓峰), Zhou Lin (周琳), Zhang Dong (章东), Gong Xiu-Fen (龚秀芬) Nonlinear propagation of focused ultrasound in layered biological tissues based on angular spectrum approach 2005 Chinese Physics 14 1594
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