“…Many proposed mechanisms, such as spallation (Lubock, 1989), geometric superfocusing (Gracewski et al, 1993;Xi and Zhong, 2001), circumferential squeezing (Eisenmenger, 2001), and shear-induced failure (Xi and Zhong, 2001;Cleveland and Sapozhnikov, 2005;Sapozhnikov et al, 2007) were demonstrated during the fragmentation process in the early stage of SWL, when the stones are of sufficient size to favor the development of large stress concentrations. Other proposed mechanisms, such as dynamic fatigue (Lokhandwalla and Sturtevant, 2000) and cavitation (Coleman et al, 1987;Sass et al, 1991;Philipp and Lauterborn, 1998), describe processes that influence stone fragmentation throughout the entire course of SWL. Despite previous efforts, a disconnection still exists between the proposed mechanisms and the lithotripter shock wave (LSW) parameters that drive the stone fracture processes in SWL (Cleveland and McAteer, 2007;Sapozhnikov et al, 2007).…”