Fabrication and evaluation of fully-sampled, two-dimensional transducer array for "Sonic Window" imaging system.
A low-cost, fully-sampled, 3600 element 2D transducer array operating at 5 MHz and designed for use in a hand-held ultrasound system is described here. Four array configurations are presented--(1) array with both matching and pedestal backing layers, (2) array with a matching layer but no backing pedestal, (3) array with a backing pedestal but no matching layer, and (4) array with neither matching layer nor backing pedestal. Each array was characterized in terms of impedance measurements, pulse-echo response, and experimental beamprofile. Comparative finite element analysis simulations are also presented. Average estimated active element yield for the four arrays was 94%. The array with pedestal layer proved the most promising, providing a 26% bandwidth and a 1.7 dB improvement in sensitivity with respect to the array with neither pedestal nor matching layer. Although this bandwidth is acceptable for our specific application (C-scan imaging), reverberations within the substrate material remain a potential challenge. We are currently working to fabricate a custom PCB material to address this concern, and may also consider using a pre-compensated transmit waveform or matched digital filter approach to further reduce the effects of such reverberations.
Eames
Matthew D C
MD
Department of Biomedical Engineering, The University of Virginia, 415 Lane Road, Charlottesville, VA 22908, USA. mde3c@Virginia.EDU
Hossack
John A
JA
D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation*; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation*