title: Combined short and long-delay tandem shock waves to improve shock wave lithotripsy according to the Gilmore-Akulichev theory.
abstract: 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.
authors.affiliation: Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Querétaro, Qro. 76230, Mexico.
authors.forename: Miguel
authors.initials: M
authors.lastname: de Icaza-Herrera
authors.affiliation: Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Querétaro, Qro. 76230, Mexico.
authors.forename: Francisco
authors.initials: F
authors.lastname: Fernández
authors.affiliation: Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Querétaro, Qro. 76230, Mexico; División de Ciencias de la Salud, Universidad del Valle de México, Villas del Mesón 1000, Querétaro, Qro. 76230, Mexico. Electronic address: loske@fata.unam.mx.
authors.forename: Achim M
authors.initials: AM
authors.lastname: Loske
mesh_terms: D000162:Acoustics; D006801:Humans; D008096:Lithotripsy / Q000379:methods*; D008962:Models, Theoretical; D014545:Urinary Calculi / Q000628:therapy
keywords: Acoustic cavitation; Extracorporeal shock wave lithotripsy; Gilmore–Akulichev formulation; Mechanical stress; Tandem shock waves