FD-TD-modeling of propagation of high energy sound pulses in lithotripter-tissue-arrangements

The numerical modeling of lithotripter pressure pulse propagation is considered. The dependence of the field parameters in the focal region on the properties of the wave propagation path is of special interest. To obtain full-wave solutions an high-order FD-TD-discretization of a set of nonlinear acoustical equations is performed. The attenuating influence of tissue layers is represented by an explicit discrete time domain operator. For the presented research the acoustical field of the Storz MODULITH SL 10 shock wave lithotripter is considered. To validate the pure lithotripter model measured wave profiles in the focal region are used. They are obtained using a fiber-optic probe hydrophone. An exemplary simulation of the propagation of the SL 10 pulse through a fluid layer with tissue-like attenuation is presented and compared with the unaffected case.