Therapeutic applications of cavitation phenomena in the medical fields

Abstract

Cavitation is an important phenomenon that has been intensively studied in the field of fluid dynamics. The formation of cavitation bubbles is induced under the condition of pressure fluctuations in a fluid, and the collapse of bubbles elicits strong effects in their surroundings. Normally, cavitation does not occur inside a biological body; however, the use of an artificial organ and irradiation of acoustic energy may induce the formation of cavitation bubbles inside the body. In this chapter, medical equipment is introduced, that induces or utilizes cavitation phenomena. A mechanical heart valve is known to generate bubbles that may cause thrombosis and valve failure, and various types of ultrasound exposure are used for medical purposes such as surgical equipment, non-invasive therapy, and drug delivery. High-speed observation plays an important role in visualizing cavitation activities generated in various applications. Results of observations provide valuable insights into the mechanisms by which cavitation bubbles elicit effects and also insights into how the effects can be minimized or maximized.