Novel fabrication of a 2D ring array for real-time volumetric endoscopic ultrasound imaging.

The work presents the development of a forward-looking 2D ring array for real-time volumetric endoscopic ultrasonic imaging using a novel rotary-dicing method. The completed array has an inner diameter of 3.5 mm, outer diameter of 5 mm, and 50 equal-area elements distributed concentrically. With a single front matching layer and a light backing, the array shows a center frequency of 3.5 MHz, a fractional bandwidth of 48%, insertion loss of -21.6 dB and cross-talk between nearest neighbor elements of 35.3 dB. The beam profile, two-dimensional pulse-echo point spread response, and phantom imaging of the array were studied with the Field-II simulation package. These promising results suggest that the rotary-dicing technology is an effective way to fabricate 2D ring array.