Human respiratory simulation based on 3D modelling - a review.

Accurate simulation of respiratory dynamics is essential for advancing the diagnosis and treatment of pulmonary diseases. This review analyzes current methodologies for modelling lung mechanics during insufflation and exsufflation, focusing on airflow simulations in the tracheobronchial tree. 45 studies were selected through a structured screening process and evaluated based on modelling approaches, simulation techniques, boundary conditions, and clinical applicability. The review identifies three main strategies for 3D TB model generation: segmentation of DICOM images, CAD-based geometries, and hybrid methods. While DICOM segmentation ensures anatomical realism, it is limited in generational depth. Conversely, CAD and hybrid approaches extend model coverage but may compromise subject specificity. Simulation methods include Computational Fluid Dynamics, Fluid-Structure Interaction, biomechanical, structural and statistical models, MR-Linac workflows, and neural networks. Among these, CFD remains the most widely adopted due to its accessibility and maturity, whereas FSI and hybrid CFD-FSI models offer superior physiological fidelity. The review wants to highlight the importance of combining detailed anatomical modelling with dynamic simulation frameworks to improve clinical interventions, particularly in lung surgery. Future work should focus on integrating patient-specific imaging, advanced boundary conditions, and multiscale modelling to enable more precise and scalable respiratory simulations.