Model demonstrates functional purpose of the nasal cycle.

Area of Science:

• Biomedical Engineering
• Respiratory Physiology
• Computational Fluid Dynamics

Background:

• The functional purpose of the nasal cycle remains unclear despite its known occurrence.
• Investigating the nasal cycle's role in maintaining airway health is crucial.

Purpose of the Study:

• To elucidate the physiological objective of the nasal cycle.
• To understand its contribution to upper airway health using a computational model.

Main Methods:

• Developed a novel state-variable heat and water mass transfer model.
• Utilized in-vivo MRI data for nasal geometry and airflow partitioning.
• Predicted airway surface liquid (ASL) hydration status in each nasal airway.

Main Results:

• The dominant airflow airway showed ASL dehydration due to heat and water transfer.
• The contralateral airway, with reduced demand, maintained ASL hydration.
• Sufficient hydration in one airway supports continuous mucociliary clearance.

Conclusions:

• The nasal cycle quantitatively facilitates contrasting upper airway functions.
• Airflow partitioning supports both air conditioning and contaminant removal.
• This mechanism ensures continuous airway health and function.