Patent ID: 7635332

Claim:
A method of ultrasonically imaging an object that reduces undesired transmitted harmonic distortion comprising the steps of: generating a plurality of transmit waveforms centered around a predetermined fundamental frequency from a plurality of microfabricated ultrasonic transducer transmit elements that are within a microfabricated transducer array, wherein at least one of the plurality of transmit waveforms generated contains the fundamental frequency and transmitted harmonic frequencies, and wherein at least a second of the plurality of transmit waveforms generates information at harmonic frequencies, the information modeling distortion created by the microfabricated transducer array; detecting return waveforms associated with the transmit waveforms that are received by microfabricated ultrasonic transducer receive elements within the microfabricated transducer array and generating return signals corresponding thereto, at least one of the return signals having the fundamental frequency and the transmitted harmonic frequencies, and wherein at least a second of the return signals having the information at the harmonic frequencies, the information modeling distortion created by the microfabricated transducer array; combining the return signals such that signal components having the transmitted fundamental frequency and the transmitted harmonic frequencies are minimized, wherein combining the return signals comprises subtracting out the information at the harmonic frequencies, the information modeling distortion created by the microfabricated transducer array; and imaging by providing data from the combined return signals which represents a harmonic image of the object having reduced transmitted harmonic distortion therein; wherein the step of generating the plurality of transmit waveforms applies a transmit signal to different transducer transmit elements, the transmit signal applied to the different transducer transmit elements differing in a delay profile; and the information at the harmonic frequencies modeling distortion created by the microfabricated transducer array are generated by alternating the polarity of the transmit signal applied to adjacent transducer transmit elements.