简易肝血管模型灌注过程中的流体动力学行为初探

Preliminary Studies on the Hydrodynamic Behaviors and Mechanisms of Hepatic Vessel Perfusion Using Simple Vessel Models

针对肝移植术前清洗器官的灌注环节所引发的血管内流体动力学行为进行研究,为术前清洗的相关操作提供理论指导。构建了带有异物的一级直血管、弯曲血管实体模型和血管内液体湍流的控制方程。实验测定医用灌注液的物理参数,提出了估算灌注技术参数的方法,实现了不同条件下的灌注仿真。基于构建的流体控制方程和血管模型进行计算,其初步结果符合医疗现场实际操作值,结果较为清晰地显示了灌注过程中(尤其是管内异物周围)的流体动力学行为,如回流滞留现象等。同时,结果也显示了血管内各处流速场大小和管壁面压强值分布。随着入口初始灌注速度的增加,两种类型的血管模型内的压强值和流速场均增大,在异物处产生壁透压和回流滞留区,同时由于弯曲血管形状的影响,其内部流体动力学行为比直血管更加复杂。

The hydrodynamic behavior of the perfusion process（cleaning）of the liver endovascular before the operation was studied to provide a theoretical guidance to the relative operations.A straight and a curved first-class vascular entity model with foreign matter and the control equations of turbulence liquid in vessel was established.With the physical parameters of a medical infusion liquid measured,an estimation method of perfusion parameters as an example,the perfusion velocity was proposed.The simulation was performed by changing technical parameters of the perfusion.Based on the control equations of turbulent liquid in vessel and the preliminarily calculated results using the vessel model,the results fitted the values of the real operation.The simulation results showed clearly the fluid dynamics behavior around the foreign matter,for example the swirling flow.The results also showed the distribution of velocity of the fluid and the wall pressure of the vessels.With the increasing velocity of the entrance perfusion,the pressure and the velocity field were increased in the two types of the vessel model.The negative wall pressure and recirculation region appeared and located in the foreign matter.Because of influence of the shape,the fluid dynamics behavior in the curved vessel model was more complicated than that in the straight vessel model.The swirling flow and the phenomenon of stagnation of the perfusion fluid were more likely to appear in the curved vessel than in the straight vessel.The most important conclusion of this paper is that the appropriate perfusion velocity can be estimated using the methods proposed in this paper.