Adaptive clutter filtering via blind signal separation for lateral blood velocity measurement

A method for adaptive clutter rejection via blind signal separation (BSS) is presented in application to angle-independent blood velocity measurement in the carotid artery. Clutter filtering via frequency domain-based approaches is ineffective given short ensemble lengths and/or overlapping axial wall and lateral blood frequency spectra. Rather than operating in the frequency domain, BSS decomposes the input data ensemble into source signals in time. The method is demonstrated using Field II simulated and clinical examples of flow in the common carotid artery. In addition to clutter rejection, the BSS technique is presented for detection of small axial flow components and filtering acoustic radiation force impulse (ARFI) displacement profiles.