Resumen
We have developed a 40-MHz, 64-element phased-array transducer packaged in a 2.5 × 3.1 mm endoscopic form factor. The array is a forward-looking semi-kerfed design based on a 0.68Pb(Mg1/3Nb2/3)O 3 ?0.32PbTiO3 (PMN-32%PT) single-crystal wafer with an element-to-element pitch of 38 μm. To achieve a miniaturized form factor, a novel technique of wire bonding the array elements to a polyimide flexible circuit board oriented parallel to the forwardlooking ultrasound beam and perpendicular to the array was developed. A technique of partially dicing into the back of the array was also implemented to improve the directivity of the array elements. The array was fabricated with a single-layer P(VDF-TrFE)-copolymer matching layer and a polymethylpentene (TPX) lens for passive elevation focusing to a depth of 7 mm. The two-way ?6-dB pulse bandwidth was measured to be 55% and the average electromechanical coupling (k eff) for the individual elements was measured to be 0.62. The one-way ?6-dB directivities from several array elements were measured to be ±20°, which was shown to be an improvement over an identical kerfless array. The ?3-dB elevation focus resulting from the TPX lens was measured to be 152 μm at the focal depth, and the focused lateral resolution was measured to be 80 μm at a steering angle of 0°. To generate beam profiles and images, the probe was connected to a commercial ultrasound imaging platform which was reprogrammed to allow for phased array transmit beamforming and receive data collection. The collected RF data were then processed offline using a numerical computing script to generate sector images. The radiation pattern for the beamformed transmit pulse was collected along with images of wire phantoms in water and tissue-equivalent medium with a dynamic range of 60 dB. Finally, ex vivo tissue images were generated of porcine brain tissue.
Idioma original | English |
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Número de artículo | 6689774 |
Páginas (desde-hasta) | 33-43 |
Número de páginas | 11 |
Publicación | IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control |
Volumen | 61 |
N.º | 1 |
DOI | |
Estado | Published - ene. 2014 |
ASJC Scopus Subject Areas
- Instrumentation
- Acoustics and Ultrasonics
- Electrical and Electronic Engineering
PubMed: MeSH publication types
- Evaluation Study
- Journal Article