High Frame Rate 3-D Ultrasound Imaging Using Separable Beamforming

Recently, there has been great interest in 3-D ultrasound imaging, but power constraints have precluded practical implementation of high-resolution and highframe-rate 3-D ultrasound in handheld imaging platforms. In this paper, we propose a separable beamforming procedure for both 3-D synthetic aperture and plane wave systems that drastically reduces computational and hence power requirements. Separable beamforming approximates 2-D array beamforming for 3-D images through a series of beamforming operations on 1-D arrays. Our proposed method is based on a separable delay decomposition method that minimizes phase error. We show that the proposed separable synthetic aperture system achieves 19-fold complexity reduction and the proposed plane wave separable system achieves 12-fold complexity reduction compared to the corresponding non-separable beamforming baseline systems. Furthermore, we verify the performance of the fixed-point-precision separable beamforming and iterative delay calculation through Field II simulations. Our results M. Yang ( ) · S. Wei · C. Chakrabarti School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, AZ 85287, USA e-mail: [email protected] S. Wei e-mail: [email protected] C. Chakrabarti e-mail: [email protected] R. Sampson · T. F. Wenisch Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109, USA e-mail: [email protected] T. F. Wenisch e-mail: [email protected] show that both the synthetic aperture system and the plane wave system can produce images with the same quality as images generated by non-separable beamforming. We also briefly describe how the two types of separable beamformer can be implemented on a modified version of Sonic Millip3De, our recently proposed hardware accelerator for the digital front-end of a 3-D ultrasound system.