Influence of stationary signals on the time-domain correlation blood flow measurement

The authors aim to produce an ultrasonic device for real-time measurement of blood flow by time-domain correlation. To investigate the influence of signals from the surrounding tissue, simulated flow signals with a stationary signal component were generated. The flow signal was then filtered by subtracting consecutive RF echoes from each other. The results show that with the stationary echo cancellation one-dimensional flow velocity profiles can be accurately calculated from 20 echoes, although stationary echoes as large as 40 dB in amplitude compared to flow signal are present. The results suggest that by applying the stationary echo cancellation and by using the high-speed residue number system correlator presented by J.T. Chen and W.K. Jenkins (1989), a successful in vivo measurement of one-dimensional flow velocity profiles should be possible in real-time despite the stationary signal