We present a new method for the geometric reconstruction of elastic surfaces simulated by the immersed boundary method with the goal of simulating the motion and interactions of cells in whole blood. Our method uses parameter-free radial basis functions for high-order meshless parametric reconstruction of point clouds and the elastic force computations required by the immersed boundary method. This numerical framework allows us to consider the effect of endothelial geometry and red blood cell motion on the motion of platelets. We find red blood cells to be crucial for understanding the motion of platelets, to the point that the geometry of the vessel wall has a negligible effect in the presence of RBCs. We describe certain interactions that force the platelets to remain near the endothelium for extended periods, including a novel platelet motion that can be seen only in 3-dimensional simulations that we term “unicycling.” We also observe red blood cell-mediated interactions between platelets and the endothelium for which the platelet has reduced speed. We suggest that these behaviors serve as mechanisms that allow platelets to better maintain vascular integrity.

我们提出了一种通过浸没边界法模拟弹性表面几何重建的新方法，目的是模拟全血中细胞的运动和相互作用。我们的方法使用无参数径向基函数进行点云的高阶无网格参数重建和浸没边界法所需的弹性力计算。这个数值框架允许我们考虑内皮几何形状和红细胞运动对血小板运动的影响。我们发现红细胞对于理解血小板的运动至关重要，以至于血管壁的几何形状在 RBC 存在下的影响可以忽略不计。我们描述了迫使血小板长时间保持在内皮附近的某些相互作用，包括一种新的血小板运动，这种运动只能在我们称之为“单轮循环”的 3 维模拟中看到。我们还观察到红细胞介导的血小板和内皮细胞之间的相互作用，血小板速度降低。我们建议将这些行为作为允许血小板更好地维持血管完整性的机制。