de Icaza-Herrera M et al, 2015: Combined short and long-delay tandem shock waves to improve shock wave lithotripsy according to the Gilmore-Akulichev theory.
de Icaza-Herrera M, Fernández F, Loske AM.
Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Querétaro, Qro. 76230, Mexico.
Extracorporeal shock wave lithotripsy is a common non-invasive treatment for urinary stones whose fragmentation is achieved mainly by acoustic cavitation and mechanical stress. A few years ago, in vitro and in vivo experimentation demonstrated that such fragmentation can be improved, without increasing tissue damage, by sending a second shock wave hundreds of microseconds after the previous wave. Later, numerical simulations revealed that if the second pulse had a longer full width at half maximum than a standard shock wave, cavitation could be enhanced significantly. On the other side, a theoretical study showed that stress inside the stone can be increased if two lithotripter shock waves hit the stone with a delay of only 20 μs. We used the Gilmore-Akulichev formulation to show that, in principle, both effects can be combined, that is, stress and cavitation could be increased using a pressure pulse with long full width at half maximum, which reaches the stone within hundreds of microseconds after two 20 μs-delayed initial shock waves. Implementing the suggested pressure profile into clinical devices could be feasible, especially with piezoelectric shock wave sources.
Ultrasonics. 2015 Apr;58:53-9. doi: 10.1016/j.ultras.2014.12.002. Epub 2014 Dec 19.