Research Article

In Vitro Demonstration of Focused Ultrasound Thrombolysis Using Bifrequency Excitation

Table 1

Peak negative and positive pressures and pulse-average intensities measured at the focal point of the transducer in water for the range of exposure level used in the experiments and for both types of excitations.

Peak pressuresSpatial-peak pulse-average intensityTotal acoustic power
(MPa) (MPa) (W/cm2)a (W)

Monofrequency excitation
33.636050
4.26.2770110
5.281200165
5.59.0220

Bifrequency excitation
5751070
69750110
6.510.5~1000a150
7.512.5220

aIntensities are estimated by integrating waveforms recorded at the focal point. At = 220 W, occurrence of cavitation prevents from giving an accurate estimation of the intensity. Bifrequency waveform at = 150 W was also perturbed by cavitation.