Efficient Multi-Fidelity Fluid–Structure Interaction Modeling for Pulsatile Blood Flow in Deformable Biological Tissues

PURPOSE: Simulating tissue deformation and flow alterations induced by external compression typically requires fluid-structure interaction (FSI) analysis, which is computationally demanding. This study presents a multi-fidelity FSI framework that efficiently captures tissue mechanics and hemodynamic responses to dynamic external pressure and demonstrates its applicability to compression therapy. METHODS: We developed an FSI model that couples a one-dimensional deformable blood flow formulation with the three-dimensional (3D) Cauchy equation of motion. Model performance was evaluated by comparing the multi-fidelity and full FSI solutions in simplified cylindrical and subject-specific geometries. As a practical demonstration, the framework was applied to simulate a full-cycle pulsatile intermittent pneumatic compression (IPC) operation. RESULTS: The model efficiently reproduced tissue deformation and hemodynamic changes under external compression, yielding