title: Multi-channel pre-beamformed data acquisition system for research on advanced ultrasound imaging methods.
abstract: The lack of open access to the pre-beamformed data of an ultrasound scanner has limited the research of novel imaging methods to a few privileged laboratories. To address this need, we have developed a pre-beamformed data acquisition (DAQ) system that can collect data over 128 array elements in parallel from the Ultrasonix series of research-purpose ultrasound scanners. Our DAQ system comprises three system-level blocks: 1) a connector board that interfaces with the array probe and the scanner through a probe connector port; 2) a main board that triggers DAQ and controls data transfer to a computer; and 3) four receiver boards that are each responsible for acquiring 32 channels of digitized raw data and storing them to the on-board memory. This system can acquire pre-beamformed data with 12-bit resolution when using a 40-MHz sampling rate. It houses a 16 GB RAM buffer that is sufficient to store 128 channels of pre-beamformed data for 8000 to 25 000 transmit firings, depending on imaging depth; corresponding to nearly a 2-s period in typical imaging setups. Following the acquisition, the data can be transferred through a USB 2.0 link to a computer for offline processing and analysis. To evaluate the feasibility of using the DAQ system for advanced imaging research, two proof-of-concept investigations have been conducted on beamforming and plane-wave B-flow imaging. Results show that adaptive beamforming algorithms such as the minimum variance approach can generate sharper images of a wire cross-section whose diameter is equal to the imaging wavelength (150 μm in our example). Also, planewave B-flow imaging can provide more consistent visualization of blood speckle movement given the higher temporal resolution of this imaging approach (2500 fps in our example).
authors.forename: Chris C P
authors.initials: CC
authors.lastname: Cheung
authors.forename: Alfred C H
authors.initials: AC
authors.lastname: Yu
authors.forename: Nazila
authors.initials: N
authors.lastname: Salimi
authors.forename: Billy Y S
authors.initials: BY
authors.lastname: Yiu
authors.forename: Ivan K H
authors.initials: IK
authors.lastname: Tsang
authors.forename: Benjamin
authors.initials: B
authors.lastname: Kerby
authors.forename: Reza Zahiri
authors.initials: RZ
authors.lastname: Azar
authors.forename: Kris
authors.initials: K
authors.lastname: Dickie