Restriction of ultrasound-induced cavitation effects in biological environment

Coupling of high-intensity ultrasound energy (HIUE) with tissue via cavitation in an aqueous medium is the main mechanism by which ultrasound may affect tissue, with the anticipation of long-term complications. The generation of cavitation in the aqueous medium is a random, complicated, threshold phenomenon, and is dependent upon many variables. The aim of our ongoing study is to clarify the mechanism of action of HIUE in biological aqueous medium with emphasis on means to improve its safety in its clinical use. High-energy chemical reactions generating oxidizing reactants, FR and SL were detected by a sensitive photomultiplying system and EPR, in a medium simulating intercellular space. The means for reduction of cavitation and its effects will be demonstrated. Applying ultrasound energy to biological systems in aqueous medium may be regarded as ionizing irradiation. Reduction of cavitation effects may improve its biosafety in its clinical application.