Systems and methods for reducing secondary hot spots in a phased array focused ultrasound system

Abstract

Systems and methods for performing a therapeutic procedure using focused ultrasound include providing a piezoelectric transducer including a plurality of transducer elements (22), such as a concave concentric ring array or a linear array of transducer elements. Drive circuitry (14) is coupled to the transducer for providing drive signals to the transducer elements at one of a plurality of discrete RF frequencies. A controller (16) is coupled to the drive circuitry for periodically changing a frequency of the drive signals to one of the plurality of discrete frequencies, while controlling a phase component of the drive signals to maintain the focus of the transducer at a primary focal zone during a single sonication.