Ultrasound imaging using single-element biaxial beamforming

Area of Science:

• Acoustics
• Signal Processing
• Medical Imaging

Background:

• Dynamic focusing, or beamforming, is crucial for ultrasound imaging, traditionally relying on sensor arrays and time-of-flight (TOF) measurements.
• Existing methods require complex sensor arrays to determine sound source location.

Purpose of the Study:

• To demonstrate passive beamforming with a single biaxial sensor.
• To achieve accurate passive acoustic mapping with two biaxial sensors using only direction of arrival (DOA) information.

Main Methods:

• Developed two single-element biaxial beamforming algorithms.
• Introduced four biaxial image reconstruction algorithms for a two-element biaxial piezoceramic transducer array.
• Performed imaging experiments in an acoustic scanning tank, contrasting performance with conventional DSAI and DMSAI algorithms.

Main Results:

• Single-element biaxial beamforming achieved a median DOA error of 0.36°.
• DOA-only images with a two-element array showed a median localization error of 6.41 mm.
• DOA + TOF images achieved a median localization error of 6.91 mm, with improved signal-to-noise ratio.

Conclusions:

• First demonstration of single-element beamforming with a stationary piezoceramic.
• First demonstration of passive ultrasound imaging without TOF information.
• Enables development of simpler, smaller, and more cost-effective passive ultrasound imaging arrays.