Characterization of dual-electrode CMUTs: demonstration of improved receive performance and pulse echo operation with dynamic membrane shaping.
A 1-D dual-electrode CMUT array for intracardiac echocardiography (ICE) with a center frequency of 8 MHz has been designed, fabricated, and used to demonstrate the potential of dual-electrode CMUTs. Using a dual-electrode CMUT, 9 dB higher receive signal level is obtained over the 6 dB fractional bandwidth as compared with a conventional CMUT with an identical center electrode biased close to its collapse voltage. Because the same device shows a 7.4 dB increase in maximum pressure output, 16.4 dB overall improvement in transduction performance has been achieved as compared with conventional CMUT. A net peak output pressure of 1.6 MPa on the dual-electrode CMUT membrane with tone burst excitation at 12 MHz is also reported. The frequency response of the dual-electrode CMUT is similar to that of a conventional CMUT with the same membrane geometry with about 15% increase in the center frequency. Monostatic operation of dual-electrode CMUTs shows that the high performance of the transducer is applicable in typical pulse-echo imaging mode of operation. With dynamic shaping of the CMUT membrane to optimize the transmit-and-receive modes of operation separately during each pulse-echo cycle, dual-electrode CMUT is a highly competitive alternative to its piezoelectric counterparts.
Guldiken
Rasim O
RO
GW Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA. gtg181u@mail.gatech.edu
Balantekin
Mujdat
M
Zahorian
Jaime
J
Degertekin
F Levent
FL
D004452:Echocardiography / Q000295:instrumentation*; D018619:Echocardiography, Doppler, Pulsed / Q000295:instrumentation*; D025802:Electric Capacitance; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods; D008567:Membranes, Artificial; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*
D008567:Membranes, Artificial