A requirement for normal breathing through the nose is an undisturbed passage through the nasal airways. If this condition is not fulfilled due to any obstruction or deformation, surgical correction of the nasal airways might be required. Rhinosurgery is a reconstructive surgical approach that reshapes the nose and/or nasal structure and often is used to correct birth defects or other breathing problems. To understand the effects of nasal anatomy on normal breathing, a team in Germany composed of members from the Zuse-Institute Berlin, Asklepios Clinic Birkenwerder and CFX Berlin Software GmbH carried out simulations using ANSYS CFX computational fluid dynamics (CFD) software. The research team based the analysis models on highly detailed internal and external nasal anatomy. The ability to simulate complex airflow characteristics with regard to individual anatomy enables the study of the physiology and pathophysiology of nasal breathing on a per patient basis. As a result, fluid flow simulations can become an extremely useful tool in treatment planning for functional rhinosurgery. For this study, the research team based their investigations on a reference model of the nasal airways created from actual human anatomy without obvious pathologic symptoms. To develop a geometric model for this case, researchers first acquired a helical computed tomography (CT) scan of a male volunteer following local administration of a decongestant. High-resolution tomography with an almost isotropic spatial resolution of 0.37 x 0.37 x 0.4 millimeters allowed for the representation of internal anatomical structures with sufficient detail. This provided the team with three-dimensional geometric information that they used to create a simulation model of the nasal and paranasal cavities. The research team then used AMIRA[4] software to reconstruct and Pathlines for air flow during inhalation, colored by velocity

Our objective is to analyze and understand the physiology and patho-physiology of normal nasal breathing. To this end, airflow simulations based on computational fluid dynamics (CFD) are presented for a highly detailed anatomy of the upper respiratory tract from the external nose to the larynx, including frontal and maxillary sinuses, as well as the ethmoid. Complex flow phenomena are investigated with regard to individual anatomy and its variations. We are aiming to gain insight into the relationship between morphology and flow behaviour in order to provide general treatment proposals and to develop computer assisted planning tools for decision support in functional rhinosurgery.

Though treatment methods in ear nose and throat surgery have constantly improved over time, the prediction of a successful individual therapy under consideration of regular nasal airflow remains a challenging task Airflow simulations based on computational fluid dynamics are presented for a highly detailed anatomy of a nasal airway including frontal and paranasal sinuses, being reconstructed from tomographic data. The simulation of complex airflow characteristics with regard to individual anatomy enables us to study the physiology and pathophysiology of nasal breathing, thus being able to support treatment planning in functional rhinosurgery.