Title :
Multi-channel pre-beamformed data acquisition system for research on advanced ultrasound imaging methods
Author :
Cheung, C.C.P. ; Yu, A.C.H. ; Salimi, N. ; Yiu, B.Y.S. ; Tsang, I.K.H. ; Kerby, B. ; Azar, R.Z. ; Dickie, K.
Author_Institution :
Ultrasonix Med. Corp., Richmond, BC, Canada
fDate :
2/1/2012 12:00:00 AM
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 25000 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, plane wave 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).
Keywords :
array signal processing; biomedical ultrasonics; data acquisition; ultrasonic imaging; DAQ system; USB 2.0 link; Ultrasonix series; adaptive beamforming algorithm; advanced ultrasound imaging; imaging depth; memory size 16 GByte; minimum variance approach; multichannel prebeamformed data acquisition system; offline processing; onboard memory; plane wave B-flow imaging; ultrasound scanner; wavelength 150 mum; wire cross section; Arrays; Connectors; Data acquisition; Gain; Imaging; Receivers; Ultrasonic imaging;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
DOI :
10.1109/TUFFC.2012.2184