High bandwidth, high density arrays for advanced ultrasound imaging

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

“…3,15 We have developed a linear-array transducer that is to be inserted into the working channel of a bronchoscope.…”

“…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.…”

Linear and curved array with advanced electroacoustic and acoustic properties

“…In this article, we present two arrays of which performances are based on optimized 1-3 piezocomposite material with innovative front acoustic matching. Last year, we have presented this design for 3.5 MHz single element and high density 192 elements array [3]. This paper presents two different configurations of 128 elements 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.…”

“…The filling resin is chosen with very low viscosity, low acoustic impedance. Moreover, piezocomposite structure is optimized [3]. The ceramic volume fraction is set to achieve a good trade-off between bulk damping, dielectric permittivity and coupling coefficient.…”

“…This backing provides sufficient damping for the piezocomposite structure and contributes to the high sensitivity of the transducer. The matching layer exhibits an impedance gradient designed to optimize the matching between the piezocomposite and the propagating medium acoustic impedance [3] and to extend the high bandwidth characteristics. Matching layer and backing material are made by mixing epoxy resins and inorganic or metallic powders.…”