PMN-PT single crystal, high-frequency ultrasonic needle transducers for pulsed-wave Doppler application.
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.
Zhou
Qifa
Q
NIH Resource on Medical Ultrasonic Transducer Technology, Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA. qifazhou@usc.edu
Xu
Xiaochen
X
Gottlieb
Emanuel J
EJ
Sun
Lei
L
Cannata
Jonathan M
JM
Ameri
Hossein
H
Humayun
Mark S
MS
Han
Pengdi
P
Shung
K Kirk
KK
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