FPGA-based real-time digital beamformer for ultrasonic elastography

This paper presents the development of a 64-channel Field Programmable Gate Array (FPGA) based digital beamformer for real-time ultrasonic elastography imaging. The hardware architecture is controlled by Altera Cyclone III FPGA ICs (EP3C16Q240, Altera Corporation) and allows flexibility for programmable aperture windowing, multiple transmit focusing phase adjustment, amplitude apodization, and dynamic receive focusing. Individual channel delays are applied using a first in first out (FIFO) structure and efficient interpolation scheme with FIR filter. A DaVinci digital video processor board (TMS320C6455 DSK, Texas Instruments Inc.) is used as the interface for image display. The system can handle up to 256-element linear array transducers and preliminary results demonstrated that real-time elastogram with fine anatomical structures can be obtained using a wire phantom with equivalent mechanical and acoustic properties of biological tissue.