Canceling the wall contamination using Doppler ultrasound signals from two consecutive cardiac cycles

An approach is presented to cancel the arterial wall contamination using audio Doppler ultrasound signals from two consecutive cardiac cycles. The wall signal is approximately periodic, while the Doppler signal from the blood flow is random because the scatters within the ultrasound sample volume are continually updated. Thus, the signal subtraction between two consecutive cardiac cycles is carried out in time domain. Simulated Doppler signals from a normal femoral artery with various clutter to blood ratios are used to validate this approach. The conventional high-pass filtering method is also carried out for comparison. The experimental results show that this approach may be a good solution for the ´wall thump´ removal when there is few difference of the wall movement between the two consecutive cardiac cycles.