A Simulation Model for Doppler Ultrasound Signals from Pulsatile Blood Flow in Stenosed Vessels

A computer simulation model is proposed to generating Doppler ultrasound signals from pulsatile blood flow in the vessels with various stenosis degrees. The model take into account velocity field from pulsatile blood flow in the stenosed vessels, sample volume shape and acoustic factors that affect the Doppler signals. By solving the Navier-Stokes equations, the velocity distributions of pulsatile blood flow in the vessels with various stenosis degrees are firstly calculated according to the velocity at the axis of the circular tube. Secondly, power spectral density (PSD) of the Doppler signals is estimated by summing the contribution of all scatterers passing through the sample volume grouped into elemental volumes. Finally, Doppler signals are generated using cosine-superposed components that are modulated by a power spectral density function varying over the cardiac cycle. The model generates Doppler blood flow signals with the characteristics similar to those found in practice. The results show that the proposed approach is useful for simulating Doppler ultrasound signals from pulsatile blood flow in stenosed vessels.