Numerical Analysis of Kidney Stone Fragmentation by Short Pulse Impingement

Abstract

In this work, numerical analyses are performed to study the behavior of stresses generated inside a kidney stone by direct pulse impingement during extracorporeal shock wave lithotripsy (ESWL), which leads to fragmentation of the stone. LS-DYNA, an explicit Finite Element code for non-linear dynamic analysis is employed to model the problems. Effects of pulse duration and acoustic property of the stone on stress field evolution inside the stone are studied for the pulse duration of 0.5 to 5.0µs and two acoustic impedances of actual kidney stones. The use of double shock wave sources to fragment the kidney stone is also considered in this paper. The effectiveness of this method for the kidney stone fragmentation is confirmed. Finally, the numerical analysis for the stone fragmentation is well compared with experimental results to confirm that the numerical analyses in this work provide reasonable results.