Ultrasound phase rotation beamforming on multi-core DSP

Area of Science:

• Medical Imaging
• Signal Processing
• Digital Hardware

Background:

• Phase rotation beamforming (PRBF) is a key digital receive beamforming technique.
• Traditionally, PRBF relies on hardware like ASICs or FPGAs due to high computational demands.

Purpose of the Study:

• Investigate the feasibility of software-based PRBF on a multi-core Digital Signal Processor (DSP).
• Reduce the computational load of PRBF for broader hardware support.

Main Methods:

• Utilized new analog front-end (AFE) chips integrating analog-to-digital conversion and quadrature demodulation.
• Implemented delay alignment and phase rotation on a Texas Instruments C6678 DSP with 8 cores.
• Assessed performance metrics for beamforming speed and sample processing capacity.

Main Results:

• Beamforming 2048 samples from 64 channels took 200 μs using 2 DSP cores.
• Achieved beamforming of 20 million samples per second with 4 DSP cores.
• Supported ADC frequencies up to 40 MHz (with decimation) or 20 MHz (without decimation).

Conclusions:

• Software-based PRBF is viable on multi-core DSPs, significantly reducing computational requirements.
• Enables DSPs to handle both beamforming and back-end processing, paving the way for low-power, cost-effective ultrasound machines.
• This advancement benefits general ultrasound imaging, especially portable applications.