Assessing the mechanism of kidney stone comminution by a lithotripter shock pulse

Journal article

Comminution of axisymmetric stones by a lithotripter shock wave was studied experimentally and theoretically. In experiments, shock waves were generated by a research electrohydraulic lithotripter modeled after the Dornier HM-3, and stones were made from U-30 cement. Cylindrical stones of various length to diameter ratios, stones of conical shape, and stones with artificial cracks were studied. In other cases, baffles to block specific waves that contribute to spallation or squeezing were used, and glycerol was used to suppress cavitation. The theory was based on the elasticity equations for an isotropic medium. The equations were written in finite differences and integrated numerically. Maximum compression, tensile and shear stresses were predicted depending on the stone shape and side-surface condition in order to investigate the importance of the stone geometry. It is shown that the theoretical model used explains the observed position of a crack in a stone. The theory also predicts the efficiency of stone fragmentation depending on its shape and size, as well as on the presence of cracks on the stone surface and baffles near the stone. © 2005 American Institute of Physics.

Authors: Sapozhnikov, O; Bailey, MR; Maxwell, A; MacConaghy, B; Cleveland, R

• Journal: AIP Conference Proceedings
• Volume: 754
• Pages: 164-166
• Publication date: 2005-03-28
• DOI: 10.1063/1.1901627
• EISSN: 1551-7616
• ISSN: 0094-243X
• Language: English