ABSTRACT A 256-element phased array has been designed, constructed, and tested for ablative treatment of large focal volumes of deep seated tissue. The array was constructed from a 1.1-MHz, 1-3 composite piezoelectric spherical shell with a 10-cm radius of curvature and a 12-cm diameter. The array was tested to determine its electroacoustic efficiency and inter-element coupling under high acoustic power conditions. A series of in vivo porcine experiments demonstrated the ability to produce deep seated tissue lesions in thigh muscle using the large scale phased array. The array was used to heat and coagulate tissue volumes› 5 cm3 in a single ultrasound exposure using multiple foci and temporally scanned power deposition patterns. The spatial and temporal experimental results for large, heated focal volumes correlated very well with the simulated temperature response model for homogeneous tissue. A 25-cm3 tissue volume was coagulated in a 90-min period using overlapping large ultrasound exposures.
1999 IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control Vol. 46, pp. 1254-1268, 1999
© 1999, by The Institute of Electrical and Electronics Engineers, Inc. All rights reserved.