I. Introduction
Passive cavitation can occur when a high-intensity focused ultrasound (HIFU) or shock wave is illuminated on a medium. The ultrasound wave induces a change in pressure as it compresses and expands the medium during its propagation, generating bubbles mainly by negative pressure. These generated bubbles suddenly shrink in an inertial manner and collapse at some time instant, causing passive ultrasonic cavitation. Ultrasonic cavitation due to bubble collapse creates secondary ultrasonic or shock waves. Since secondary ultrasonic waves generated in a series of processes such as bubble generation due to HIFU, dynamic behavior of bubbles, and inertial collapse cause various ultrasonic effects such as cell and stone destruction, it is very important to monitor and track ultrasonic waves generated due to ultrasonic cavitation [1]–[6].