体外衝撃波結石破砕療法に伴う衝撃波パルス人体内非線形伝搬

一近似解析

抄録

A simple method based on the Finite-Difference Time-Domain(FD-TD) method is presented for analyz-ing nonlinear propagation of strong ultrasonic pulses in water. First, the present method is applied to the problem of plane-wave nonlinear propagation which is often used to explain nonlinear phenomena, and the results are compared with theoretical results. Then a model is prepared for the numerical simulation of the Reichenberger's experimental setup in which the ultrasonic pulse radiated from electromagnetic acoustic sources is focussed by a lens. The present method is applied to this model for simulating the shock wave propagation. The results show that the present method can simulate the real shock wave nonlinear propaga-tion in water with fairly high accuracy, provided that supersonic nonlinear parameters in water are assumed to be higher than those known thus far.