ABSTRACT
Conversations (normal speech) or professional interactions (e.g., projected speech in the classroom) have been identified as situations with increased risk of exposure to SARS-CoV-2 due to the high production of droplets in the exhaled air. However, it is still unclear to what extent speech properties influence droplets emission during everyday life conversations. Here, we report the experimental protocol of three experiments aiming at measuring the velocity and the direction of the airflow, the number and size of droplets spread during speech interactions in French. We consider different phonetic conditions, potentially leading to a modulation of speech droplets production, such as voice intensity (normal vs. loud voice), articulation manner of phonemes (type of consonants and vowels) and prosody (i.e., the melody of the speech). Findings from these experiments will allow future simulation studies to predict the transport, dispersion and evaporation of droplets emitted under different speech conditions. © European Language Resources Association (ELRA), licensed under CC-BY-NC-4.0.
ABSTRACT
Face masks are used worldwide to reduce COVID-19 transmission in indoor environments. Differently from face respirators, there are no standards methods for measuring the fraction of air leaking at the face seal of loose-fitting masks such as medical and community masks. This study applies a recently developed method to quantify air leakage at the face seal to 14 medical and community mask models with the aim to understand the role of mask design and filter properties in air leakage. An instrumented head-form equipped with sensors for measuring volumetric airflow and differential pressure was used to simulate the air exhalation from the mouth of a person wearing a face mask. Results showed that the fraction of leaking air at the face seal is not negligible and can range from 10% to 95% according to mask model. The higher the exhaled airflow rate and the lower the amount of leaking fraction. A strong correlation was found between leaking fraction and filter breathability, indicating that a better breathability can lower air leakage. Highly breathable filtering materials should be employed in the production of medical and community face masks to maximize user comfort and minimize the fraction of exhaled air leaking unfiltered at the face seal. © 2022 IEEE.
ABSTRACT
Biomarkers seem to play an important role in understanding various diseases’ nature, course and management, including respiratory ones. Yet, discovering verifiable and validated ones, that are useful in pulmonology, is challenging and constant. A special body specimen that has been characterized as a matrix of biomarkers, is the exhaled breath condensate (EBC). It is a fluid resulting from freezing the exhaled air. Water is its main constituent. The rest is a rich mix of water-soluble volatile compounds and aerosol droplets of airway lining fluid. The droplets carry non-volatile organic compounds. Their concentration is very small and the techniques applied to measure it are very accurate and sensitive. The content of the exhaled breath condensate reflects important processes taking place in the lungs, such as inflammation and oxidative stress, which are the basis of respiratory diseases’ pathophysiology. It seems that it has a role in diagnosis, monitoring, stratification and therapy of respiratory diseases, including COVID19. This paper presents information on exhaled breath condensate and highlights its importance as a potential source of biomarkers. © 2022, Springer Nature Switzerland AG.
ABSTRACT
The current COVID-19 pandemic has increased the use of facial masks globally, which of late have registered their presence as a part of our civilization. The N95 mask is one of the most popular choices under the current situation. However, the available masks cannot provide breathing comfort for an extended period, which results in rebreathing of exhaled air that is CO2 rich, and which remains in the breathing space of the respirator. Furthermore, problems like moisture settlement on the covered area of the face due to the multiple layers of fabric-like material causes significant discomfort. Hence, the need for a mask with an air-purification activity is the need of the hour. The present innovation relates to the invention of a mask that is battery-powered or solar-operated and addresses the aforementioned problems. This mask not only regulates the airflow, which is beneficial to our body in every way, but also lowers the discomfort of sweating and heating. The effect of the addition of the self-developed active respirator to the commercially available masks on the inspired CO2 level, thermal comfort, and speech clarity has been demonstrated in this study. We have exhibited through in vitro experiments that the filtration capability of the active-respirator improvised mask, we call the Bose shield, does not deter from that of the standard N95 mask. To our understanding, the use of this novel mask can reduce the occurrence of CO2 rebreathing in respiratory protective devices and its impact on workers who inevitably wear them for a prolonged period of time. © 2022 Author(s).
ABSTRACT
The coronavirus-19 pandemic has shown that early diagnosis of structural changes in lung tissue is essential. However, many remote medical institutions lack the necessary equipment, such as a computed tomography scanner. In this work, we want to present the developed concept of a device that allows registering lung tissue abnormalities at early stages by detecting biomarkers in liquid droplets and human respiration. © 2022 IEEE.
ABSTRACT
Respiratory viruses are transported from an infected person to other neighboring people through respiratory droplets. These small droplets are easily advected by air currents in a room and can potentially infect others. In this work, the spread of droplets released during coughing, talking, and normal breathing is numerically analyzed in a typical conference room setting. The room space is occupied by ten people, with eight people sitting around a conference table and two people standing. Four different scenarios are considered, with the air-conditioning turned on/off and people wearing/not-wearing masks, to understand the spread of respiratory droplets inside the room. The flow in the room is simulated using a multiphase mixture model with properties computed for the inhaled and exhaled air using fundamental gas relations. The transport of respiratory droplets is analyzed using the discrete phase model with a range of droplet sizes fitted to data from previous experimental studies. The mask is modeled as porous media with the properties of a woven fabric computed using a newly developed model for multilayered homemade masks. The human inhalation and exhalation are modeled using analytical functions to mimic the biological flow patterns during breathing, coughing, and talking. Important observations about the air flow and dispersion of respiratory droplets in the conference room are presented based on the numerical analysis. Animations of all the results are included to provide insight into flow physics of the various dynamic conditions occurring in the room during an ongoing meeting. Although this study is conducted for a typical conference room, the newly developed models and techniques can be applied to other confined environments. © 2022 Author(s).
ABSTRACT
Possible plasma and photonic methods and devices for monitoring and preventing dangerous infections and human diseases are presented. In experiments with different types of atmospheric pressure discharges in different gases, the significant bactericidal effect was found. The prototype of device based on the method of absorption spectroscopy for detecting human diseases by biomarkers in the exhaled air has been proposed and tested. The importance of the plasma technology of deposition of coatings by magnetron sputtering for the creation of anti-covid masks and high-quality optics (mirrors) for photon monitoring devices is emphasized. © 2021 Institute of Physics Publishing. All rights reserved.