A hardware efficient beamformer for small ultrasound scanners

Abstract

Digital receive beamformer is one of the most important parts governing the performance and complexity of a medical ultrasound imaging system. In this presentation, we present a hardware efficient digital beamformer for small size ultrasound scanners, which is advantageous over the two most widely used beamforming schemes, interpolation beamformer and phase rotation beamformer, in terms of hardware complexity and performance. Interpolation beamformer requires a multi-tap interpolation filter for each channel to obtain 1/16f0 delay resolution. Phase rotation beamformer requires IQ demodulation and performs inter-channel delay compensation by shifting the phase of inphase and quadrature components. The proposed beamformer is identical to the interpolation beamformer except that it uses fractional delay (FD) filters to generate the delayed samples. FD filters were designed using least square error method to obtain an optimum performance for a given hardware complexity. The results show that the proposed method outperforms other beamforming methods.I.

Efficient Parallel-Beamforming Based on Shared FIFO for Ultra-Compact Ultrasound Imaging Systems

“…where 4) The block data sets are parallelized, and fed into the FD filters [27], [29], [30], which yield a fractionallydelayed RF data samples. For example, 8-tap FD filters optimized for the frequency spectrum can provide group delay responses in the frequency range from 0 to 15 MHz when 40-MHz f s is employed, without altering magnitude responses ( Figure 2).…”