Elimination of cavitation-related attenuation in shock wave lithotripsy

Conference Paper

In shock wave lithotripsy (SWL), acoustic pulses with a leading compression wave followed by a tensile wave are delivered into the patient's body using a water-filled coupling cushion. Cavitation-related acoustic energy loss in the coupling unit depends critically on water conditions, e.g. dissolved gas concentration and exchange flow rate. We have systematically investigated the attenuation mechanism in the coupling water via pressure measurements and cavitation characterization. In non-degassed water the bubble cluster became progressively dense (i.e., proliferated because of gas diffusion into bubbles and splitting of bubbles into many daughter bubbles) in shock waves delivered at 1 Hz leading to reduction in the tensile wave duration from a nominal value of 4.6 to 1.8 μs. To reduce cavitation in the coupling water along the beam path, we have used a continuous jet flow to remove residual daughter bubbles between consecutive shocks. As a result, stone fragmentation efficiency was increased from 16±4% to 30±5% (p = 0.002) after 250 shocks. Such a hydrodynamic approach for tensile wave attenuation in the coupling water may be used to provide a flexible means for a novel treatment strategy with tissue protection.

Full Text

Duke Authors

Cited Authors

  • Sankin, GN; Lautz, JM; Simmons, WN; Zhong, P; Frank, ST; Szeri, AJ

Published Date

  • March 17, 2017

Published In

Volume / Issue

  • 1821 /

Electronic International Standard Serial Number (EISSN)

  • 1551-7616

International Standard Serial Number (ISSN)

  • 0094-243X

International Standard Book Number 13 (ISBN-13)

  • 9780735414891

Digital Object Identifier (DOI)

  • 10.1063/1.4977638

Citation Source

  • Scopus