COVID‐19 in the Clinic: Human Testing of an Aerosol Containment Mask for Endoscopic Clinic Procedures

Abstract

Objective To create an aerosol containment mask (ACM) for common otolaryngologic endoscopic procedures that also provides nanoparticle-level protection to patients. Study Design Prospective feasibility study . Setting In-person testing with a novel ACM. Methods The mask was designed in Solidworks and 3D printed. Measurements were made on 10 healthy volunteers who wore the ACM while reading the Rainbow Passage repeatedly and performing a forced cough or sneeze at 5-second intervals over 1 minute with an endoscope in place. Results There was a large variation in the number of aerosol particles generated among the volunteers. Only the sneeze task showed a significant increase compared with normal breathing in the 0.3-µm particle size when compared with a 1-tailed t test ( P = .013). Both the 0.5-µm and 2.5-µm particle sizes showed significant increases for all tasks, while the 2 largest particle sizes, 5 and 10 µm, showed no significant increase (both P < .01). With the suction off, 3 of 30 events (2 sneeze events and 1 cough event) had increases in particle counts, both inside and outside the mask. With the suction on, 2 of 30 events had an increase in particle counts outside the mask without a corresponding increase in particle counts inside the mask. Therefore, these fluctuations in particle counts were determined to be due to random fluctuation in room particle levels. Conclusion ACM will accommodate rigid and flexible endoscopes plus instruments and may prevent the leakage of patient-generated aerosols, thus avoiding contamination of the room and protecting health care workers from airborne contagions. Level of evidence 2

COVID‐19 in the Clinic: Trial of an Aerosol Containment Mask for Endoscopic Clinic Procedures

“…Therefore, we made statistical comparisons between the distribution of raw sensor particle counts during normal breathing compared to during endoscopy. Previously, we had determined that the largest changes occurred in the 0.3 μm particle count with sneezing, coughing, or phonating, which is why we have focused our analysis on this particle size 8 …”

“…The ACM was designed by the authors and created using Solidworks (Dassault Systemes) and printed using a 3D printer (Ultimaker) using “tough PLA (polylactic acid).” Initial prototypes were tested by the authors on endoscopic surgery model heads in order to gauge access to the nasal cavity and the ability to contain aerosols, as reported in prior publications 5,6 . An additional pilot study of 10 volunteers who completed endoscopy and common vocalization procedures was also performed 8 …”

Diagnostic and surgical innovations in otolaryngology for adult and paediatric patients during the COVID-19 era

“…Another 3D-printed mask was tested – first on mannequins and then on human volunteers – by Ference et al 26 , 27 ( Fig. 4 ).…”

“… An aerosol containment mask for endoscopy: ( A ) mask architecture; ( B ) mask on patient; ( C ) patient undergoing endoscopy (from Ference et al, 2021 27 ). …”

Innovative dual‐function protective scope mask and filtration system for aerosol generating ENT scope procedures

“…Surgical masks also do not protect against leakage of aerosols or droplets from the corners of the mask, and more so if the mask fits poorly. Ference et al 12 had described a 3D printed N95 respirator fitted opaque scope mask made from a tough polylactic acid, which is connected to normal suction device. This mask is also not entirely sterilizable.…”