Development and Assessment of an Inexpensive Smartphone-Based Respiratory Droplet Simulation Model

Background. Droplet simulation often requires expensive and inaccessible equipment. Herein, we develop and assess a low-cost droplet simulation model using easily accessible materials, open-source software, and a smartphone-based cobalt blue light. Methods. The simulation model was developed using commercial-grade materials and fluorescein dye. A clear face shield was assessed ten times following a simulated cough using fluorescein dye. A conventional ultraviolet Woods lamp was compared to a smartphone-based cobalt blue light to detect fluorescein illumination. Results. The simulation platform and smartphone-based cobalt blue light cost $20.18. A Wilcoxon signed rank test revealed that the median droplet area of fluorescence under the UV Wood's lamp was not significantly different than that of the smartphone-based cobalt blue light (2.89 vs 2.94, P = .386). Conclusions. This simulation model is inexpensive and easily reproducible. The smartphone application may be a convenient alternative to standard ultraviolet lights. This model has great potential for use in financially restricted academic centers during the COVID-19 pandemic and beyond.