A new beamformer based on phase dispersion to improve 2D sparse array response

This work studies a new beamformer for non-periodic sparse bidimensional ultrasonic array transducer. It is based on a weighting factor based on signals phase dispersion to enhance the image points where the phase coherence between the received signals is high. A method to measure the phase dispersion based on Fourier analysis and its integration in the beamformer are presented. Its performance is evaluated using a non-periodic 2D sparse array based on Fermat spiral with 96 elements and a diameter of 60λ. Compared with conventional Delay-And-Sum beamformer the proposed solution reduces the aperture lateral resolution and improves its dynamic range, achieving up to 50dB of contrast in the image and less 1° in lateral resolution.

[1]  Caroline Holmes,et al.  Advanced post-processing for scanned ultrasonic arrays: application to defect detection and classification in non-destructive evaluation. , 2008, Ultrasonics.

[2]  P. Cochat,et al.  Et al , 2008, Archives de pediatrie : organe officiel de la Societe francaise de pediatrie.

[3]  R. Y. Chiao,et al.  Coded excitation for diagnostic ultrasound: a system developer's perspective , 2003, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[4]  L. G. Ullate,et al.  2D array design based on Fermat spiral for ultrasound imaging. , 2010, Ultrasonics.

[5]  J. Camacho,et al.  Phase Coherence Imaging , 2009, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.