Pressure distribution and energy flow in the focal region of two different electromagnetic shock wave sources.

In extracorporeal shock wave lithotripsy there is still a lack of knowledge about the basic physical terms that are essential for a scientific comparison of lithotripters with different technologies. The main goal of this article is to introduce the relation between pressure distribution, acoustic energy flow and intensity. The procedure of how these data can be achieved quantitatively is described. Technical data of two different commercially available electromagnetic shock wave sources are presented. The results show that acoustic energy flow and intensity depend on the variation of the shock wave parameters and the focal area.