Experimental Investigation of Inter-Element Isolation in a Medical Array Transducer at Various Manufacturing Stages.

Experimental Investigation of Inter-Element Isolation in a Medical Array Transducer at Various Manufacturing Stages.
Ultrason Imaging. 2015 Jul 9;
Authors: Marinozzi F, Bini F, Grandoni A
Abstract
This work presents the experimental investigation of vibration maps of a linear array transducer with 192 piezoelements by means of a laser Doppler vibrometer at various manufacturing finishing steps in air and in water. Over the years, many researchers have investigated cross-coupling in fabricated prototypes but not in arrays at various manufacturing stages. Only the central element of the array was driven at its working frequency of 5 MHz. The experimental results showed that the contributions of cross-coupling depend on the elements of the acoustic stack: Lead Zirconate Titanate (PZT), kerf, filler, matching layer, and lens. The oscillation amplitudes spanned from (6 ± 38%) nm to (110 ± 40%) nm when the energized element was tested in air and from (6 ± 57%) nm to (80 ± 67%) nm when measurements were obtained under water. The best inter-element isolation of -22 dB was measured in air after cutting the kerfs, whereas the poorest isolation was -2 dB under water with an acoustic lens (complete acoustic stack). The vibration pattern in water showed a higher standard deviation on the displacement measurements than the one obtained in air, due to the influence of acousto-optic interactions. The amount increased to 30% in water, as estimate...

Source: Ultrasonic Imaging - July 15, 2015 Category: Radiology Tags: Ultrason Imaging Source Type: research