Proposal of a new slit-lamp shield for ophthalmic examination and assessment of its effectiveness using computational simulations

• Autor(a) principal: Ferraz,Daniel Araújo
• Data de Publicação: 2022
• Outros Autores: Guan,Zeyu, Costa,Edinilson A., Martins,Eduardo, Keane,Pearse A., Ting,Daniel Shu Wei, Belfort Jr,Rubens, Scherer,Rafael, Koh,Victor, Muccioli,Cristina
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Arquivos brasileiros de oftalmologia (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0004-27492022005006204
• topic: Ophthalmologi sts; Coronavirus infections/prevention & control;Pandemics; Lipid droplets; SARS-CoV-2; Slit-lamp; Computer simulation; Protectivedevices; Equipment design

ABSTRACT Purpose: This study aimed to use computational models for simulating the movement of respiratory droplets when assessing the efficacy of standard slit-lamp shield versus a new shield designed for increased clinician comfort as well as adequate protection. Methods: Simulations were performed using the commercial software Star-CCM+. Respiratory droplets were assumed to be 100% water in volume fraction with particle diameter distribution represented by a geometric mean of 74.4 (±1.5 standard deviation) μm over a 4-min duration. The total mass of respiratory droplets expelled from patients’ mouths and droplet accumulation on the manikin were measured under the following three conditions: with no slit-lamp shield, using the standard slit-lamp shield, and using our new proposed shield. Results: The total accumulated water droplet mass (kilogram) and percentage of expelled mass accumulated on the shield under the three aforementioned conditions were as follows: 5.84e-10 kg (28% of the total weight of particle emitted that settled on the manikin), 9.14e-13 kg (0.045%), and 3.19e-13 (0.015%), respectively. The standard shield could shield off 99.83% of the particles that would otherwise be deposited on the manikin, which is comparable to 99.95% for the proposed design. Conclusion: Slit-lamp shields are effective infection control tools against respiratory droplets. The proposed shield showed comparable effectiveness compared with conventional slit-lamp shields, but with potentially enhanced ergonomics for ophthalmologists during slit-lamp examinations.