The Research on Doppler Ultrasonic Blood Flow Signals under Periodically Pulsatile Flow Based on STFT

As a noninvasive method, the Doppler ultrasound technique is used to detect cardiovascular disease. Doppler ultrasonic signals of periodic oscillatory blood flow in the circular tube were simulated in this paper. Firstly, by solving the Navier_Stokes equations of periodically oscillatory blood flow, the distributions of pressure gradient and blood velocity in varying-area vessel were obtained. Then, the Doppler ultrasound blood flow signals were simulated using the cosine summation method. Finally, to illustrate this method, simulated Doppler signals were analyzed using the short-time Fourier transform (STFT), which can provide a valid approach for the analysis of Doppler ultrasound signals.