Characterization of nasal irrigation flow from a squeeze bottle using computational fluid dynamics

Area of Science:

• Biomedical Engineering
• Computational Fluid Dynamics
• Rhinology

Background:

• Nasal saline irrigation is a standard treatment for sinonasal conditions like rhinitis and chronic rhinosinusitis.
• Limited experimental models hinder understanding of nasal irrigation dynamics.
• This study utilizes computational fluid dynamics (CFD) to model nasal irrigation.

Purpose of the Study:

• To develop a CFD model of nasal irrigation.
• To analyze sinonasal surface coverage, fluid residence times, and shearing forces.
• To elucidate the physical mechanisms of nasal irrigation.

Main Methods:

• A 3D nasal cavity model was created from CT scans of a healthy adult.
• CFD analysis simulated irrigation from a squeeze bottle at a 45-degree head tilt.
• Simulations assessed fluid distribution at 35 mL/second for 2 seconds.

Main Results:

• The model precisely measured irrigation velocity, pressure, and wall shear stress.
• Nasal cavity coverage was nearly complete.
• Moderate coverage (40%) of maxillary and (30%) ethmoid sinuses occurred via overflow; sphenoid and frontal sinuses had negligible coverage.

Conclusions:

• Detailed physical mechanisms of nasal irrigation were visualized.
• Maxillary and ethmoid sinus penetration results from overflow, not direct jetting.
• Larger irrigation volumes are recommended to enhance sinus ostia coverage.