An Novel Clutter Rejection Filters Applied to Wideband Blood Flow Velocity Estimation
Color flow imaging plays a major role in the diagnosis of many vascular diseases, especially cardiovascular disease. The imaging quality is highly influenced by the clutter originating from the vascular wall, stationary and slowly moving tissues and relative motion between the probe held by doctor and the blood flow. The clutter rejection filter in front of the mean frequency estimator will restrict the mean frequency estimation range because the power of the signal component induced by slowly moving blood is suppressed as well. Therefore, a novel scheme, using parameter estimation methods based on the two-dimensional correlation function model (2DCM) and the conventional down mixing, is proposed to clutter rejection. With the parameter estimation methods based on the 2DCM, both the center frequency and the mean Doppler frequency are estimated. The two dimensional information in range gate has been also sufficiently used. Simulation results have shown that this adaptive scheme has achieved superior performance in wideband blood flow velocity estimation