Nonlinear Acoustics FDTD method including Frequency Power Law Attenuation for Soft Tissue Modeling
Year: 2014
Type: preprint
Abstract: This paper describes a model for nonlinear acoustic wave propagation through absorbing and weakly dispersive media, and its numerical solution by means of finite differences in time domain method (FDTD). The attenuation is based on multiple relaxation processes, and provides frequency dependent absorption and dispersion without using computational expensive convolutional operators. In this way, by using an optimization algorithm the coefficients for the relaxation processes can be obtained in order to fit a frequency power law that agrees the experimentally measured attenuation data for heterogeneous media over the typical frequency range for ultrasound medical applications. Our results show that two relaxation processes are enough to fit attenuation data for most soft tissues in this frequency range including the fundamental and the first ten harmonics. Furthermore, this model can fit experimental attenuation data that do not follow exactly a frequency power law over the frequency range of interest. The main advantage of the proposed method is that only one auxiliary field per relaxation process is needed, which implies less computational resources compared with time-domain fractional derivatives solvers based on convolutional operators.
Source: arXiv (Cornell University)
Institutions: Universitat Politècnica de València, Columbia University
Language: English
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
Open Access status: green
Awards: G614241084, G7598673873
OpenAlex ID: W1883448212