A novel SPH-based method for fiber orientation and detailed simulation of patient-specific vascular fluid–structure interactions

In patient-specific simulation of vascular fluid–structure interaction, the incorporation of key biomechanical factors, such as fiber structures, physiological initial and boundary conditions, is crucial for enhancing the fidelity and reliability of the results. However, incorporating these factors remains challenging due to the lack of effective modeling methods. This study proposes a novel smoothed particle hydrodynamics (SPH)-based method for modeling fiber orientation. The proposed method, based on the Laplace-Dirichlet rule-based method (LDRBM), leverages particle ‘color’ and SPH interpolation to enhance robustness and versatility. With this method, the fiber effects alongside prestress and tissue support are integrated into SPH-based simulations for the first time. The proposed methods are validated by simulating pulsatile flow in a straight vessel and further applied to patient-specific cases of cerebral aneurysm and aortic dissection. The results demonstrate that the proposed method produces more reasonable fiber orientations in complex blood vessels when compared with the traditional LDRBM. Moreover, the incorporation of biomechanical factors such as prestress and tissue support significantly improves the physiological fidelity in predicting the mechanical behavior of vessels, demonstrating the effectiveness of the proposed method and highlighting the importance of detailed vascular FSI simulation.