High-frequency transducers based on integrated piezoelectric thick films for medical imaging.
A screen-printed PZT thick film with a final thickness of about 40 microm was deposited on a porous PZT substrate to obtain an integrated structure for ultrasonic transducer applications. This process makes it possible to decrease the number of steps in the fabrication of high-frequency, single-element transducers. The porous PZT substrates allow high acoustic impedance and attenuation to be obtained, satisfying transducer backing requirements for medical imaging. The piezoelectric thick films deliver high electromechanical performance, comparable to that of standard bulk ceramics (thickness coupling factor over 45%). Based on these structures, high-frequency transducers with a center frequency of about 25 MHz were produced and characterized. As a result, good sensitivity and axial resolution were obtained in comparison with similar transducers integrating a lead titanate (PT) disk as active material. The two transducers were integrated into a high-frequency imaging system, and comparative skin images are shown.
Maréchal
Pierre
P
Francois-Rabelais University, Laboratory of UltraSound Signal and Instrumentation, 37032 Tours, France . marechal@univ-tours.fr
Levassort
Franck
F
Holc
Janez
J
Tran-Huu-Hue
Louis-Pascal
LP
Kosec
Marija
M
Lethiecq
Marc
M
D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D008567:Membranes, Artificial; D019047:Phantoms, Imaging; D011846:Radio Waves; D012867:Skin / Q000000981:diagnostic imaging*; D018511:Systems Integration; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods
D008567:Membranes, Artificial