Ultrasonic diagnostic system using a nonlinearity of an examined body with respect to propagation of ultrasonic wave

摘要

An ultrasonic diagnostic system includes a transducer. A first electric drive signal is fed to the transducer. A second electric drive signal is fed to the transducer at a time different from a time of the feed of the first electric drive signal thereto. The second electric drive signal has a waveform different from a waveform of the first electric drive signal. A first received signal is derived from an output signal of the transducer. The first received signal represents ultrasonic echoes related to an ultrasonic beam caused by the transducer in response to the first electric drive signal. A second received signal is derived from the output signal of the transducer. The second received signal represents ultrasonic echoes related to an ultrasonic beam caused by the transducer in response to the second electric drive signal. The first received signal is subjected to a waveform equalizing process, thereby being converted into a third received signal having a waveform corresponding to a waveform of the second received signal. A calculator operates for calculating a difference between the second received signal and the third received signal, and generating a signal representing the calculated difference.