| High intensity focused ultrasound (HIFU) guided by magnetic resonance imaging (MRI) is a noninvasive treatment that can potentially reduce morbidity, lower costs, and widen accessibility for patients with upper abdominal cancers. Traditionally, piezoelectric transducers are used for HIFU, but recent developments in capacitive micromachined ultrasonic transducers (CMUTs) have made them competitive. Previously, we designed, fabricated, and tested HIFU CMUTs for use under MRI guidance and demonstrated successful unfocused heating of a HIFU phantom. In this paper, we use this CMUT design in the construction of an 8-element, equal area, concentric ring array for ablation of upper abdominal cancers. We report on the measurement of the beam profile of the transducer and compare it to models; in addition, we report on the effects of acoustic crosstalk on this array. |