Assessment of facial and ocular deposition of nebulized aerosol using a color-based method.

Purpose: The objective of this investigation was to develop an inexpensive and uncomplicated color-based method to rapidly assess undesirable facial and ocular deposition of aerosolized droplets on the surface of a 3D rigid replica of a 4-year-old child's face.

Methods: Sar-Gel(®), which changes color on contact with water, was evenly coated on the face model through which air was drawn using two breathing patterns (representing moderate and shallow inhalations) or a constant rate of 0, 10, and 20 L/min. A standard and two proprietary (one shaped to resemble a fish face, the other shaped to resemble a dragon face) pediatric facemasks were evaluated. A nebulizer was charged with 3 mL of normal saline before connection to the facemask. The mask was held in contact with the face using 300 g-F determined by instrumenting the mounting strap using a force gauge. The nebulizer was operated for 5 minutes. The region of color change was captured using a digital camera and analyzed using Adobe(®) Photoshop.

Results: Facial and ocular deposition with all the facemasks was affected by breathing pattern. Compared to the standard and dragon masks, the fish mask resulted in significantly reduced facial and ocular deposition at all breathing patterns.

Conclusions: This simple screening method allows quantification of droplet deposition outside the facemask and may be a useful tool for designing masks that result in reduced facial and ocular deposition.