Beam space processing for low-cost scanners

A subaperture processing technique suitable for low-cost ultrasound imaging systems is presented. The technique is based on multi-element synthetic aperture approach and beam interpolation. A large receive aperture is synthesized using a transmit subaperture at the transducer array center and a number of non-overlapping receive subapertures multiplexed across the array. The number of beam lines scanning a sector angle is chosen according to the spatial Nyquist criteria of a single transmit-receive subaperture. The beam count is increased through digital interpolation, where a linear filter with a different spatial frequency band for each subaperture is employed. This technique reduces the number of firings in data acquisition and hence permits real-time synthetic aperture processing with low susceptibility to motion artifacts.