Doppler ultrasound simulation model for pulsatile flow with nonaxial components.

A numerical model that can produce pulsed Doppler signals for nonaxial, pulsatile flow is presented. The model takes into account both hemodynamic and acoustic factors that affect the Doppler signal, such that a wide range of flow patterns and arbitrary transducer types can be simulated. The physics of blood flow is modeled by solving the Navier-Stokes equations utilizing a finite element technique, and the acoustic field is modeled using the acoustic impulse response method. The model was validated by comparison to the Womersley theory. The median deviation was 3.45%. Doppler signals from flow through a 50% stenosis were also simulated. The calculated spectra demonstrated the changing flow patterns from jets and vortices. This new computer model can be used to test spectral analysis tools on simulated Doppler signals, whose underlying flow patterns are of clinical importance.