Dual frequency cavitation event sensor with iodide dosimeter

• The inertial cavitation activity were investigated using iodide dosimetry.
• The continuous mode for dual frequency sonication is more effective than other combinations.
• The optimization of dual frequency sonication parameters can be useful for sonodynamic therapy.

The inertial cavitation activity depends on the sonication parameters. The purpose of this work is development of dual frequency inertial cavitation meter for therapeutic applications of ultrasound waves. In this study, the chemical effects of sonication parameters in dual frequency sonication (40 kHz and 1 MHz) were investigated in the progressive wave mode using iodide dosimetry. For this purpose, efficacy of different exposure parameters such as intensity, sonication duration, sonication mode, duty factor and net ultrasound energy on the inertial cavitation activity have been studied. To quantify cavitational effects, the KI dosimeter solution was sonicated and its absorbance at a wavelength of 350 nm was measured. The absorbance values in continuous sonication mode was significantly higher than the absorbance corresponding to the pulsed mode having duty factors of 20–80% (p < 0.05). Among different combination modes (1 MHz100% + 40 kHz100%, 1 MHz100% + 40 kHz80%, 1 MHz80% + 40 kHz100%, 1 MHz80% + 40 kHz80%), the continuous mode for dual frequency sonication is more effective than other combinations (p < 0.05). The absorbance for this combined dual frequency mode was about 1.8 times higher than that obtained from the algebraic summation of single frequency sonications. It is believed that the optimization of dual frequency sonication parameters at low-level intensity (<3 W/cm2) by optically assisted cavitation event sensor can be useful for ultrasonic treatments.