NONLINEAR PROPAGATION IN DOPPLER ULTRASOUND

The nonlinear propagation of ultrasound was demonstrated using Doppler transducers on two commercial duplex machines. The influence of nonli near propagation on Doppler measurements was studied on both a flow ph antom and a string phantom. It was found that although the pulse wavef orms showed clearly different degrees of nonlinear distortion, no effe ct due to the nonlinearity could be detected on the received Doppler s pectrum both in terms of the maximum frequency or underlying Doppler s pectral profile.