Progress in Two-Dimensional Arrays for Real-Time Volumetric Imaging

Abstract

The design, fabrication, and evaluation of two dimensional array transducers for real-time volumetric imaging are described. The transducers we have previously described operated at frequencies below 3 MHz and were unwieldy to the operator because of the interconnect schemes used in connecting to the transducer handle. Several new transducers have been developed using new connection technology. A 40 × 40 = 1,600 element, 3.5 MHz array was fabricated with 256 transmit and 256 receive elements. A 60 × 60 = 3,600 element 5.0 MHz array was constructed with 248 transmit and 256 receive elements. An 80 × 80 = 6,400 element, 2.5 MHz array was fabricated with 256 transmit and 208 receive elements. 2-D transducer arrays were also developed for volumetric scanning in an intracardiac catheter, a 10 × 10 = 100 element 5.0 MHz forward-looking array and an 11 × 13 = 143 element 5.0 MHz side-scanning array. The −6 dB fractional bandwidths for the different arrays varied from 50% to 63%, and the 50 Ω insertion loss for all the transducers was about −64 dB. The transducers were used to generate real-time volumetric images in phantoms and in vivo using the Duke University real time volumetric imaging system, which is capable of generating multiple planes at any desired angle and depth within the pyramidal volume.