FDTD Analysis of ESWL Focal Neighborhood Sound Pressure Distribution
体外冲击波碎石焦点附近声压分布的时域有限差分法数值解析

Stone disease of the urinary system is a kind of frequently-occuring disease. The patient suffered from this disease is very painful. In extracorporeal shock wave lithotripsy (ESWL), high intensity ultrasonic pulse is generated outside the human body, and focused via water to human body. The kidney and ureter stones are crushed by the shock wave in focus, and discharged from human body by the urine. The ESWL has come into wide use due to its non-invasive advantage. However, when crushing stone in human body by ESWL, it often happens to complications, such as bloody urine and kidney hematoma. The medical treatment effect of ESWL was affected by the sound pressure distribution near an ESWL focus. This study analyzes ultrasonic pulse nonlinear propagation using ultrasonic nonlinear propagation simulation FDTD (finite difference time domain) method proposed by author before, and examines the sound pressure distribution near a focus, size and form of focal region and the focal position of the converged ultrasonic.