论文部分内容阅读
目的模拟Dornier HM3碎石机椭球反射体的边缘位置附加不同角度反射器时体外冲击波聚焦粉碎结石术(extracorporeal shock wave lithotripsy,ESWL)的压力场变化。方法利用空间轴对称Euler方程和混合网格改进的CE/SE数值格式,对ESWL中附加反射器所改变的冲击波聚焦压力场进行模拟。结果对不同角度附加反射器焦点附近的压力值进行比较发现,附加反射器使整个流场的正负压力峰值显著增大,与没有附加反射器的结果相比增大近50%;压力场中压力峰值随着附加反射器角度的增大而逐渐减弱,45°比0°峰值减少了约25%。结论在碎石初始阶段,附加反射器带来的能量汇聚效应将结石粉碎成更细的小块,因而可以降低放电轰击频率而达到同样或者更高的碎石效率。数值模拟结果为ESWL碎石机的改进和临床应用提供了可靠的数值计算结果和有益的参考。
Objective To simulate the pressure field changes of extracorporeal shock wave lithotripsy (ESWL) at the edge of Dornier HM3 lithotripsy ellipsoid reflector with different angle reflectors attached. Methods By using the space-axisymmetric Euler equation and the modified CE / SE numerical scheme of hybrid grid, the shock wave focusing pressure field changed by the additional reflector in ESWL was simulated. Results Compared with the pressure near the focal point of the additional reflector at different angles, the additional reflector significantly increased the positive and negative pressure peaks of the whole flow field, which increased nearly 50% compared with the results without the additional reflector. In the pressure field The peak pressure diminishes as the additional reflector angle increases, decreasing by about 25% at 45 ° over the 0 ° peak. Conclusion In the initial stages of gravel, the additional energy from the reflector causes the stones to break into finer pieces, thus reducing the discharge impact frequency to achieve the same or higher gravel efficiency. Numerical simulation results provide reliable numerical results and useful references for the improvement and clinical application of ESWL lithotripsy machine.