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

OBJECTIVE: Create an aerosol containment mask (ACM) for common otolaryngologic endoscopic procedures which 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 3-dimensional printed. Measurements were made on 100 consecutive clinic patients who underwent medically necessarily endoscopy, 50 rigid nasal and 50 flexible, by 9 surgeons. RESULTS: Of the 50 patients who underwent rigid nasal endoscopy with the ACM, 0 of 25 patients with the suction off and 0 of 25 patients with the suction on had evidence of leakage of 0.3 µm particles. Of the 50 patients who underwent flexible endoscopy with the ACM, 0 of 25 patients with the suction off and 0 of 25 patients with the suction on had evidence of leakage of 0.3 µm particles. In terms of comfort, 73% of patients found the ACM somewhat or very comfortable without suction, compared to 86% with the suction on. Surgeons were able to visualize all necessary anatomic areas in 98% of procedures. In 97% of procedures, the masks were able to be placed easily. CONCLUSION: ACM can accommodate rigid nasal and flexible endoscopes and may prevent leakage of patient-generated aerosols, thus avoiding contamination of the room and protecting health care workers from airborne contagions. LEVEL OF EVIDENCE: The level of evidence is 2.

Multi-window approach enables two-fold improvement in OCT axial resolution with strong side-lobe suppression and improved phase sensitivity.

A common processing approach for optical coherence tomography (OCT) uses a window function (e.g., Hann or rectangular window) for spectral shaping prior to calculating the Fourier transform. Here we build on a multi-window approach [Opt. Express8, 5267 (2017)10.1364/BOE.8.005267] that enables improved resolution while still suppressing side-lobe intensity. The shape of the window function defines the trade-off between main-lobe width (resolution) and side-lobe intensity. We have extended the approach to include the interferometric phase for phase-sensitive applications like vibrometry and Doppler OCT. Using the Hann window as a reference, we show that 11 Taylor windows are sufficient to achieve 50% improvement in axial resolution, -31 dB side-lobe intensity, and 20% improvement in phase sensitivity with low computational cost.

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

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.