The fabrication and integration of a 15 MHz array within a biopsy needle

Abstract

It is proposed that integrating ultrasound transducer arrays at the tip of tools such as biopsy needles could enable valuable, real-time image feedback during interventional procedures. High-resolution ultrasound imaging has the potential to aid navigation of interventional tools, and to assist diagnosis or treatment via in-vivo tissue characterisation in the breast, amongst many other applications. In order to produce miniature transducer arrays incorporated within biopsy needle-sized packages (2-5 mm diameter), the challenges in micromachining and handling transducer materials at this scale must be overcome. This paper presents fabrication processes used in the micromachining of a 16 element 15 MHz PIN-PMN-PT piezocrystal-polymer composite array and its integration into an 11 G breast biopsy needle. Particular emphasis is given to the manufacturing of the 1-3 dice-and-fill piezocrystal composite, and establishing electrical interconnects. Characterisation measurements have demonstrated operation of each of the 16 elements within the needle case.

Design and Simulation of a Ring-Shaped Linear Array for Microultrasound Capsule Endoscopy

“…of 10 mm, this gives p = 61.4 μm and w = 49.1 μm. The element separation is then 12.3 μm, similar to the smallest value physically possible with mechanical dicing of an array during fabrication [36], [37]. The tx elements are based on array of the same size, but with only eight elements of 3.93 mm in arc length.…”