A pseudo-spectral time-domain method for ultrasound wave propagation in soft biological tissue

We introduce a Pseudo-Spectral Time-Domain (PSTD) method to simulate acoustic wave propagation in soft biological tissues, incorporating frequency-dependent power-law absorption and dispersion. A comprehensive Von-Neumann stability analysis highlights the influence of material parameters, time step, and spatial discretization on numerical stability. Validation is conducted through one-dimensional tests comparing numerical results with theoretical predictions for dispersion and attenuation, and two-dimensional simulations benchmarked against analytical Green's functions. Additionally, forward simulations on a breast phantom model using typical ultrasound parameters demonstrate the method's accuracy in modeling wave attenuation and dispersion. This PSTD method provides a reliable and efficient computational tool for advanced biomedical ultrasonics research.