An ultrasound transducer having multiple focal zones is described. In one embodiment there is an ultrasound transducer manufactured as a single piece but having two or more focal zones. In a second embodiment there is a transducer assembly combining a high frequency and low frequency transducer. In a...http://www.google.es/patents/US20050154314?utm_source=gb-gplus-sharePatente US20050154314 - Component ultrasound transducer
