The Research Of Using Ultrasonic Nonlinear Parameter B/A To Measure The Temperature In Media

An advanced ultrasonic pulse-echo method is developed which uses a new kind of BI-frequency ultrasonic focused piezoelectric transducer to precisely measure the nonlinear parameter B/A without being effected by the scattering characteristics of the media. It was proved to be a practical method of noninvasive in-vivo temperature measurement in Hyperthermia. In this paper, the theory is strictly analysised and different parameter matches are discussed. A physical system was built up and it was proved to have satisfied the hypothesis and simplification of this method through experiments testing. Also, the nonlinear parameter has been got through experiments at certain temperature.