Shock wave lithotripsy and therapy.

The biological effects of ultrasound exposure are classified into thermal and mechanical effects. The medical application of shock waves has been explored widely as a technique that exerts a mechanical effect with no thermal effect on the living body. The application of shock waves started in urology as a method to disintegrate calculi by impulsive force. During widespread use in urology, it was confirmed that shock waves could also induce some changes in the bones and soft tissues located in the propagation path, and application of shock waves in the field of orthopedics is currently under intensive investigation. In this brief review, we first discuss the similarities of and differences between shock waves and ultrasound. The characteristics of shock wave sources used to generate therapeutic shock waves are then described, and the mechanisms by which shock waves induce stone fragmentation and other therapeutic effects are discussed.