title: PMN-PT single crystal, high-frequency ultrasonic needle transducers for pulsed-wave Doppler application.
abstract: High-frequency needle ultrasound transducers with an aperture size of 0.4 mm were fabricated using lead magnesium niobate-lead titanate (PMN-33% PT) as the active piezoelectric material. The active element was bonded to a conductive silver particle matching layer and a conductive epoxy backing through direct contact curing. An outer matching layer of parylene was formed by vapor deposition. The active element was housed within a polyimide tube and a 20-gauge needle housing. The magnitude and phase of the electrical impedance of the transducer were 47 omega and -38 degrees, respectively. The measured center frequency and -6 dB fractional bandwidth of the PMN-PT needle transducer were 44 MHz and 45%, respectively. The two-way insertion loss was approximately 15 dB. In vivo high-frequency, pulsed-wave Doppler patterns of blood flow in the posterior portion and in vitro ultrasonic backscatter microscope (UBM) images of the rabbit eye were obtained with the 44-MHz needle transducer.
authors: NIH Resource on Medical Ultrasonic Transducer Technology, Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA. qifazhou@usc.edu
authors: Qifa
authors: Q
authors: Zhou
authors: Xiaochen
authors: X
authors: Xu
authors: Emanuel J
authors: EJ
authors: Gottlieb
authors: Lei
authors: L
authors: Sun
authors: Jonathan M
authors: JM
authors: Cannata
authors: Hossein
authors: H
authors: Ameri
authors: Mark S
authors: MS
authors: Humayun
authors: Pengdi
authors: P
authors: Han
authors: K Kirk
authors: KK
authors: Shung
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods; D008904:Miniaturization; D009339:Needles; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers; D018617:Ultrasonography, Doppler, Pulsed / Q000295:instrumentation* / Q000379:methods