Linear and curved array with advanced electroacoustic and acoustic properties

Abstract

Recent advances in ultrasound medical imaging such as contrast agent, harmonic or sonar type imaging require ultrasound arrays with higher electro-acoustical and acoustical performances than the standard state of the art. Higher bandwidth, higher sensitivity, better resolution and improved beam characteristics are necessary to improve image quality. This paper presents two different configurations of array transducers: a 3.5 MHz center frequency curved linear array for general purpose, abdominal and obstetric imaging and a 7 MHz center frequency linear array for small parts and peripheral vascular imaging. Both arrays include optimized 1-3 piezocomposite material based on high dielectric permittivity piezoceramic. These arrays that use new acoustic matching design exhibit a higher bandwidth with a +15% to 25% gain compared to standard ones with high resolution resulting in a wide operating frequency range. Complete electroacoustic and acoustic evaluations of both arrays are presented in this paper. To characterize and evaluate the electroacoustic performances, we propose to set a figure of merit.

Feasability of human endobronchial imaging with a linear‐array ultrasound catheter

“…The matching layer was designed with an impedance gradient to optimize the impedance matching between the piezocomposite and the propagating medium acoustic. 14,15 Matching layer and backing material (low impedance backing layer: Z 5 1.5 Mrayls) were made by mixing epoxy resins and inorganic or metallic powders.…”