A method for imaging a target includes the steps of transmitting ultrasonic energy at a fundamental frequency and receiving reflected ultrasonic energy at a harmonic of the fundamental frequency. The ultrasonic energy is transmitted in power bursts, each having a respective envelope shape, wherein the...http://www.google.fr/patents/US6226228?utm_source=gb-gplus-shareBrevet US6226228 - Ultrasonic harmonic imaging system and method
