A Two-Way FSI Model for Pathologic Respiratory Processes with Precisely Structured and Flexible Upper Airway

The human body displays various symptoms of altitude sickness due to hypoxia in environments with low pressure and oxygen levels. While existing studies are primarily focused on the adverse effects of hypoxia and oxygen supplementation strategies at high altitudes, there is a notable gap in understanding the fundamental mechanisms driving altitude hypoxia. In this context, we propose a sophisticated two-way fluid–structure interaction model that simulates respiratory processes with precisely structured and deformable upper airways. This model reveals that, under identical pressure differentials at the airway’s inlet and outlet, the inspiratory air volume remains largely consistent and is minimally affected by specific pressure changes. However, an increase in the pressure differential enhances gas inhalation efficiency. Furthermore, airway morphology emerges as a pivotal factor influencing oxygen intake. Distorted airway shapes create areas of high flow velocity, where low wall pressure hampers effective airway opening, thus diminishing gas inhalation. These results may shed light on the effects of low-pressure conditions and upper airway structure on respiratory dynamics at high altitudes and inform the development of effective oxygen supply strategies.