Numerical Investigation of Burst Wave Lithotripsy and Synthesis of Shock and Burst Waves

The burst wave lithotripsy is a cutting-edge non-invasive treatment for kidney stones. Due to their paramount importance, efforts for elevating the effectiveness of non-invasive treatment have been always amongst researchers’ top priorities. The purpose of the current study is numerically investigating the details of exerted stress and the effects of some parameters such as pressure amplitude, frequency and stone’s material for burst wave lithotripsy, and feasibility study of the synthesis of shock and burst waves. In addition, thermal side effects are investigated on surrounding tissues for both methods. The COMSOL Multiphysics based on finite element method is utilized to couple and solve the governing non-linear equations of acoustic wave propagation, the elasticity of structure and biological heat transfer. The results for BWL show that increases in pressure amplitude do not change the distribution of von Mises stress. In addition, increasing frequency leads to a reduction of the focal region, which reduced damages to adjacent tissues. The result for the synthesis of the shock wave and burst wave shows that due to the return of the shock wave from the stone, a wall of compressive wave is created in the front of the stone, and it prevents the burst wave to reach the stone. Therefore, the location of the maximum pressure changes and side effects on the kidney tissue increases.