Robust Capon Beamformer with frequency Smoothing applied to medical ultrasound imaging

Abstract

In recent years, Robust Capon Beamformer with Spatial Smoothing (RCB-SS) has improved ultrasound imaging. The RCB-SS is implemented in the time domain and spatial smoothing has the disadvantage of reducing the effective aperture leading to lower lateral resolution. In this paper, we propose a new adaptive beamformer in the frequency domain using frequency smoothing. We investigate the performance of our method using experimental data and compare its performance with RCB-SS and Delay and Sum (DAS) beam-former. Our method has a narrower mainlobe width, lower sidelobes, stronger interference suppression, less speckle and better reconstruction at higher depths than RCB-SS and DAS beamforming. The proposed method also shows better performance when the aperture size is reduced, thus allowing higher frame rates and lower data storage.