Reduction of ultrasound inertial cavitation threshold using bifrequency excitation

Within the scope of an application to transcutaneous ultrasonic thrombolysis, this study compares inertial cavitation thresholds obtained at the focus of a transducer for two types of ultrasonic excitations: a classical one frequency signal and an excitation combining two slightly different frequencies. A cepstral filtering method is used to measure inertial cavitation activity for these signals. A 30% reduction of the threshold is observed when using bifrequency excitation.