Comparison of an Air-Fed Mask System with Hospital-Issued Personal Protection Equipments for Dental Aerosol Protection During the COVID-19 Pandemic

Aim: A pilot study was conducted with the aim of developing a system to protect the eyes, nose, and mouth from the aerosol generated from a high-speed dental handpiece during the COVID-19 pandemic. Background: The SARS-CoV-2 virus is known to be present in the saliva of an infected individual during the contagious viral shedding phase of the disease. The use of rotary dental instruments places oral health practitioners at risk of contracting COVID-19 from infected individuals. In particular, it is very difficult to protect the mucous membranes of the face against the extremely fine aerosol produced from a high-speed dental handpiece. Objectives: This study aimed to develop and test a novel PPE system for use during the COVID-19 pandemic. An air-fed spray-painting mask was used under a plastic hood to protect against the aerosol from a high-speed dental handpiece. This was found to be superior compared to hospital-issued N-95 masks and eye protection in our test model. Methods: Subjects donned various forms of PPE whilst using a high-speed dental handpiece in a confined cubicle. The efficacy of each form of PPE was evaluated by adding fluorescein to the water coolant supply line of a high-speed dental handpiece before checking for facial contamination with an ophthalmology slit lamp. Results: Under our test conditions, the N-95 mask did not prevent nasal and mouth contaminations, but the combination of an air-fed mask with a sealed hood prevented these contaminations. Although goggles worn tightly did prevent contamination, the air-fed mask system was far more comfortable and did not fog up. Discussion: Under the rigorous test conditions of our model, we found hospital-issued PPE ineffective. We also found the single strategy of using positive airflow into a face mask ineffective, even with extremely high levels of airflow. Complete protection was only achieved reliably by the combination of physically sealing off the face from the surrounding airspace and using the air-fed system to provide an external source of air to breathe. We effectively made the clinical equivalent of a dive bell helmet. The air-fed mask is supplied by a standard dental air compressor and is simple to install for someone familiar with the technical aspects of compressors. The compressor does not rely on a filter and proves effective with cheap and easily accessible disposable items. Conclusion: Under rigorous testing conditions, the developed air-fed mask system with a sealed hood on low flow performed better than hospital-issued PPE against high-speed dental aerosol protection. The developed system protects the operators from the air of the room contaminated with aerosol and brings in safe air from the outside for them to breathe.

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Human respiratory input impedance between 32 and 800 Hz, measured by interrupter technique and forced oscillations

Journal of Applied Physiology ◽

10.1152/jappl.1997.82.3.1018 ◽

1997 ◽

Vol 82 (3) ◽

pp. 1018-1023 ◽

Cited By ~ 12

Author(s):

Urs Frey ◽

Bela Suki ◽

Richard Kraemer ◽

Andrew C. Jackson

Keyword(s):

High Frequency ◽

Input Impedance ◽

High Speed ◽

Signal To Noise Ratio ◽

Acoustic Resonance ◽

Face Mask ◽

Forced Oscillations ◽

Tissue Resistance ◽

Wide Range ◽

The Face

Frey, Urs, Bela Suki, Richard Kraemer, and Andrew C. Jackson. Human respiratory input impedance between 32 and 800 Hz, measured by interrupter technique and forced oscillations. J. Appl. Physiol. 82(3): 1018–1023, 1997.—Respiratory input impedance (Zin) over a wide range of frequencies ( f) has been shown to be useful in determining airway resistance (Raw) and tissue resistance in dogs or airway wall properties in human adults. Zin measurements are noninvasive and, therefore, potentially useful in investigation of airway mechanics in infants. However, accurate measurements of Zin at these f values with the use of forced oscillatory techniques (FOT) in infants are difficult because of their relatively high Raw and large compliance of the face mask. If pseudorandom noise pressure oscillations generated by a loudspeaker are applied at the airway opening (FOT), the power of the resulting flow decreases inversely with f because of capacitive shunting into the volume of the gas in the speaker chamber and in the face mask. We studied whether high-frequency respiratory Zin can be measured by using rapid flow interruption [high-speed interrupter technique (HIT)], in which we expect the flow amplitude in the respiratory system to be higher than in the FOT. We compared Zin measured by HIT with Zin measured by FOT in a dried dog lung and in five healthy adult subjects. The impedance was calculated from two pressure signals measured between the mouth and the HIT valve. The impedance could be assessed from 32 to 800 Hz. Its real part at low f as well as the f and amplitude of the first and second acoustic resonance, measured by FOT and by HIT, were not significantly different. The power spectrum of oscillatory flow when the HIT was used showed amplitudes that were at least 100 times greater than those when FOT was used, increasing at f > 400 Hz. In conclusion, the HIT enables the measurement of high-frequency Zin data ranging from 32 to 800 Hz with particularly high flow amplitudes and, therefore, possibly better signal-to-noise ratio. This is particularly important in systems with high Raw, e.g., in infants, when measurements have to be performed through a face mask.

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Examining the interplay between face mask usage, asymptomatic transmission, and social distancing on the spread of COVID-19

Scientific Reports ◽

10.1038/s41598-021-94960-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Adam Catching ◽

Sara Capponi ◽

Ming Te Yeh ◽

Simone Bianco ◽

Raul Andino

Keyword(s):

Social Distance ◽

Large Fraction ◽

Real Life ◽

Virus Transmission ◽

Face Mask ◽

Social Distancing ◽

Viral Spread ◽

The Face ◽

Asymptomatic Individuals ◽

High Virus

AbstractCOVID-19’s high virus transmission rates have caused a pandemic that is exacerbated by the high rates of asymptomatic and presymptomatic infections. These factors suggest that face masks and social distance could be paramount in containing the pandemic. We examined the efficacy of each measure and the combination of both measures using an agent-based model within a closed space that approximated real-life interactions. By explicitly considering different fractions of asymptomatic individuals, as well as a realistic hypothesis of face masks protection during inhaling and exhaling, our simulations demonstrate that a synergistic use of face masks and social distancing is the most effective intervention to curb the infection spread. To control the pandemic, our models suggest that high adherence to social distance is necessary to curb the spread of the disease, and that wearing face masks provides optimal protection even if only a small portion of the population comply with social distance. Finally, the face mask effectiveness in curbing the viral spread is not reduced if a large fraction of population is asymptomatic. Our findings have important implications for policies that dictate the reopening of social gatherings.

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Effects of Face Mask Use on Objective and Subjective Measures of Thermoregulation During Exercise in the Heat

Sports Health A Multidisciplinary Approach ◽

10.1177/19417381211028212 ◽

2021 ◽

pp. 194173812110282

Author(s):

Ayami Yoshihara ◽

Erin E. Dierickx ◽

Gabrielle J. Brewer ◽

Yasuki Sekiguchi ◽

Rebecca L. Stearns ◽

...

Keyword(s):

Exercise Intensity ◽

Thermal Sensation ◽

Face Mask ◽

Whole Body ◽

Moderate Exercise ◽

Physically Active ◽

Time Points ◽

The Face ◽

And Control ◽

Moderate Exercise Intensity

Background: While increased face mask use has helped reduce COVID-19 transmission, there have been concerns about its influence on thermoregulation during exercise in the heat, but consistent, evidence-based recommendations are lacking. Hypothesis: No physiological differences would exist during low-to-moderate exercise intensity in the heat between trials with and without face masks, but perceptual sensations could vary. Study Design: Crossover study. Level of Evidence: Level 2. Methods: Twelve physically active participants (8 male, 4 female; age = 24 ± 3 years) completed 4 face mask trials and 1 control trial (no mask) in the heat (32.3°C ± 0.04°C; 54.4% ± 0.7% relative humidity [RH]). The protocol was 60 minutes of walking and jogging between 35% and 60% of relative VO2max. Rectal temperature (Trec), heart rate (HR), temperature and humidity inside and outside of the face mask (Tmicro_in, Tmicro_out, RHmicro_in, RHmicro_out) and perceptual variables (rating of perceived exertion (RPE), thermal sensation, thirst sensation, fatigue level, and overall breathing discomfort) were monitored throughout all trials. Results: Mean Trec and HR increased at 30- and 60-minute time points compared with 0-minute time points, but no difference existed between face mask trials and control trials ( P > 0.05). Mean Tmicro_in, RHmicro_in, and humidity difference inside and outside of the face mask (ΔRHmicro) were significantly different between face mask trials ( P < 0.05). There was no significant difference in perceptual variables between face mask trials and control trials ( P > 0.05), except overall breathing discomfort ( P < 0.01). Higher RHmicro_in, RPE, and thermal sensation significantly predicted higher overall breathing discomfort ( r2 = 0.418; P < 0.01). Conclusion: Face mask use during 60 minutes of low-to-moderate exercise intensity in the heat did not significantly affect Trec or HR. Although face mask use may affect overall breathing discomfort due to the changes in the face mask microenvironment, face mask use itself did not cause an increase in whole body thermal stress. Clinical Relevance: Face mask use is feasible and safe during exercise in the heat, at low-to-moderate exercise intensities, for physically active, healthy individuals.

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Effect of Mouth Mask and Face Shield on Speech Spectrum in Slovak Language

Applied Sciences ◽

10.3390/app11114829 ◽

2021 ◽

Vol 11 (11) ◽

pp. 4829

Author(s):

Vojtech Chmelík ◽

Daniel Urbán ◽

Lukáš Zelem ◽

Monika Rychtáriková

Keyword(s):

Speech Intelligibility ◽

Face Mask ◽

Suprasternal Notch ◽

Lombard Effect ◽

Slavic Languages ◽

Female Speech ◽

The Face ◽

Frequency Components ◽

Acoustic Filtering ◽

Filtering Effect

In this paper, with the aim of assessing the deterioration of speech intelligibility caused by a speaker wearing a mask, different face masks (surgical masks, FFP2 mask, homemade textile-based protection and two kinds of plastic shields) are compared in terms of their acoustic filtering effect, measured by placing the mask on an artificial head/mouth simulator. For investigating the additional effects on the speaker’s vocal output, speech was also recorded while people were reading a text when wearing a mask, and without a mask. In order to discriminate between effects of acoustic filtering by the mask and mask-induced effects of vocal output changes, the latter was monitored by measuring vibrations at the suprasternal notch, using an attached accelerometer. It was found that when wearing a mask, people tend to slightly increase their voice level, while when wearing plastic face shield, they reduce their vocal power. Unlike the Lombard effect, no significant change was found in the spectral content. All face mask and face shields attenuate frequencies above 1–2 kHz. In addition, plastic shields also increase frequency components to around 800 Hz, due to resonances occurring between the face and the shield. Finally, special attention was given to the Slavic languages, in particular Slovak, which contain a large variety of sibilants. Male and female speech, as well as texts with and without sibilants, was compared.

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Antibacterial and In Vivo Studies of a Green, One-Pot Preparation of Copper/Zinc Oxide Nanoparticle-Coated Bandages

Membranes ◽

10.3390/membranes11070462 ◽

2021 ◽

Vol 11 (7) ◽

pp. 462

Author(s):

Archana R. Deokar ◽

Ilana Perelshtein ◽

Melissa Saibene ◽

Nina Perkas ◽

Paride Mantecca ◽

...

Keyword(s):

Zinc Oxide ◽

Metal Oxide ◽

Ultrasound Irradiation ◽

Face Mask ◽

In Vivo Studies ◽

One Pot ◽

The Face ◽

Bulk Scale ◽

Particle Size And Shape

Simultaneous water and ethanol-based synthesis and coating of copper and zinc oxide (CuO/ZnO) nanoparticles (NPs) on bandages was carried out by ultrasound irradiation. High resolution-transmission electron microscopy demonstrated the effects of the solvent on the particle size and shape of metal oxide NPs. An antibacterial activity study of metal-oxide-coated bandages was carried out against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative). CuO NP-coated bandages made from both water and ethanol demonstrated complete killing of S. aureus and E. coli bacteria within 30 min., whereas ZnO NP-coated bandages demonstrated five-log reductions in viability for both kinds of bacteria after 60 min of interaction. Further, the antibacterial mechanism of CuO/ZnO NP-coated bandages is proposed here based on electron spin resonance studies. Nanotoxicology investigations were conducted via in vivo examinations of the effect of the metal-oxide bandages on frog embryos (teratogenesis assay—Xenopus). The results show that water-based coatings resulted in lesser impacts on embryo development than the ethanol-based ones. These bandages should therefore be considered safer than the ethanol-based ones. The comparison between the toxicity of the metal oxide NPs prepared in water and ethanol is of great importance, because water will replace ethanol for bulk scale synthesis of metal oxide NPs in commercial companies to avoid further ignition problems. The novelty and importance of this manuscript is avoiding the ethanol in the typical water:ethanol mixture as the solvent for the preparation of metal oxide NPs. Ethanol is ignitable, and commercial companies are trying the evade its use. This is especially important these days, as the face mask produced by sonochemistry (SONOMASK) is being sold all over the world by SONOVIA, and it is coated with ZnO.

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IoT and Deep Learning Based Approach for Rapid Screening and Face Mask Detection for Infection Spread Control of COVID-19

Applied Sciences ◽

10.3390/app11083495 ◽

2021 ◽

Vol 11 (8) ◽

pp. 3495

Author(s):

Shabir Hussain ◽

Yang Yu ◽

Muhammad Ayoub ◽

Akmal Khan ◽

Rukhshanda Rehman ◽

...

Keyword(s):

Deep Learning ◽

Low Cost ◽

Face Mask ◽

World Health ◽

Rapid Screening ◽

Screening System ◽

Source Of Infection ◽

The Face ◽

Health Organization ◽

Vaccine Distribution

The spread of COVID-19 has been taken on pandemic magnitudes and has already spread over 200 countries in a few months. In this time of emergency of COVID-19, especially when there is still a need to follow the precautions and developed vaccines are not available to all the developing countries in the first phase of vaccine distribution, the virus is spreading rapidly through direct and indirect contacts. The World Health Organization (WHO) provides the standard recommendations on preventing the spread of COVID-19 and the importance of face masks for protection from the virus. The excessive use of manual disinfection systems has also become a source of infection. That is why this research aims to design and develop a low-cost, rapid, scalable, and effective virus spread control and screening system to minimize the chances and risk of spread of COVID-19. We proposed an IoT-based Smart Screening and Disinfection Walkthrough Gate (SSDWG) for all public places entrance. The SSDWG is designed to do rapid screening, including temperature measuring using a contact-free sensor and storing the record of the suspected individual for further control and monitoring. Our proposed IoT-based screening system also implemented real-time deep learning models for face mask detection and classification. This module classified individuals who wear the face mask properly, improperly, and without a face mask using VGG-16, MobileNetV2, Inception v3, ResNet-50, and CNN using a transfer learning approach. We achieved the highest accuracy of 99.81% while using VGG-16 and the second highest accuracy of 99.6% using MobileNetV2 in the mask detection and classification module. We also implemented classification to classify the types of face masks worn by the individuals, either N-95 or surgical masks. We also compared the results of our proposed system with state-of-the-art methods, and we highly suggested that our system could be used to prevent the spread of local transmission and reduce the chances of human carriers of COVID-19.

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Facial Recognition System for People with and without Face Mask in Times of the COVID-19 Pandemic

Sustainability ◽

10.3390/su13126900 ◽

2021 ◽

Vol 13 (12) ◽

pp. 6900

Author(s):

Jonathan S. Talahua ◽

Jorge Buele ◽

P. Calvopiña ◽

José Varela-Aldás

Keyword(s):

Facial Recognition ◽

Face Mask ◽

Recognition System ◽

Classification Model ◽

World Health ◽

The Face ◽

Recognition Systems ◽

Facial Recognition System ◽

Health Organization ◽

Face Detector

In the face of the COVID-19 pandemic, the World Health Organization (WHO) declared the use of a face mask as a mandatory biosafety measure. This has caused problems in current facial recognition systems, motivating the development of this research. This manuscript describes the development of a system for recognizing people, even when they are using a face mask, from photographs. A classification model based on the MobileNetV2 architecture and the OpenCv’s face detector is used. Thus, using these stages, it can be identified where the face is and it can be determined whether or not it is wearing a face mask. The FaceNet model is used as a feature extractor and a feedforward multilayer perceptron to perform facial recognition. For training the facial recognition models, a set of observations made up of 13,359 images is generated; 52.9% images with a face mask and 47.1% images without a face mask. The experimental results show that there is an accuracy of 99.65% in determining whether a person is wearing a mask or not. An accuracy of 99.52% is achieved in the facial recognition of 10 people with masks, while for facial recognition without masks, an accuracy of 99.96% is obtained.

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Shock Tube as an Impulsive Application Device

International Journal of Aerospace Engineering ◽

10.1155/2017/2010476 ◽

2017 ◽

Vol 2017 ◽

pp. 1-12 ◽

Cited By ~ 4

Author(s):

Soumya Ranjan Nanda ◽

Sumit Agarwal ◽

Vinayak Kulkarni ◽

Niranjan Sahoo

Keyword(s):

Heat Transfer ◽

Shock Tube ◽

High Speed ◽

Force Measurement ◽

Peak Load ◽

Wave Force ◽

Impulsive Loading ◽

Force Balance ◽

Test Model ◽

Impulse Facility

Current investigations solely focus on application of an impulse facility in diverse area of high-speed aerodynamics and structural mechanics. Shock tube, the fundamental impulse facility, is specially designed and calibrated for present objectives. Force measurement experiments are performed on a hemispherical test model integrated with the stress wave force balance. Similar test model is considered for heat transfer measurements using coaxial thermocouple. Force and heat transfer experiments demonstrated that the strain gauge and thermocouple have lag time of 11.5 and 9 microseconds, respectively. Response time of these sensors in measuring the peak load is also measured successfully using shock tube facility. As an outcome, these sensors are found to be suitable for impulse testing. Lastly, the response of aluminum plates subjected to impulsive loading is analyzed by measuring the in-plane strain produced during deformation. Thus, possibility of forming tests in shock is also confirmed.

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A Novel Artificial Face Mask based Nanofibers with Special Intelligent Engineered Nanocomposite Against Covid-19

10.54216/jcim.050203 ◽

2021 ◽

pp. PP. 21-22

Author(s):

Ahmed A. Elngar ◽

◽

S.I. El El-Dek

Keyword(s):

Artificial Intelligence ◽

Resource Allocation ◽

Pattern Recognition ◽

Disease Management ◽

Face Mask ◽

Vital Role ◽

Mobile Unit ◽

Disease Clusters ◽

Infected People ◽

The Face

We introduce our idea about a new face mask against Covid-19. Herein our novel face mask is a polymeric matrix of nanofibers. These nanofibers are decorated with special engineered nanocomposite. The later possesses antiviral, antimicrobial. A well-established IR temperature biosensor will be implanted in the face mask and connected to the mobile phone using App (Seek thermal) to allow temperature monitoring. Artificial Intelligence can play a vital role in the fight against COVID-19. AI is being successfully used in the identification of disease clusters, monitoring of cases, prediction of the future outbreaks, mortality risk, diagnosis of COVID-19, disease management by resource allocation, facilitating training, record maintenance and pattern recognition for studying the disease trend. Therefore, AI is used as a type of alarm which be connected through Global Position System (GPS) to a central networking system to monitor the crowded areas of probable infections. In this case, the hospital in this neighborhood will be charged to let a mobile unit of assessment travel quickly to the infected people areas.

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Mythologizing the face mask: How protective covers became political during the fine-dust and COVID-19 crises in South Korea

International Journal of Media and Cultural Politics ◽

10.1386/macp_00044_1 ◽

2021 ◽

Vol 17 (2) ◽

pp. 97-117 ◽

Cited By ~ 1

Author(s):

Tae-Sik Kim

Keyword(s):

News Media ◽

Face Mask ◽

Risk Society ◽

Fine Dust ◽

South Korean ◽

Korean Government ◽

External Threat ◽

The Face ◽

Primary Means ◽

Symbolic Code

This study aimed to demonstrate how South Korean news media routinized and sensationalized the face mask amid two recent public health crises: the fine-dust crisis and the COVID-19 epidemic. News media appropriated the mythologized meaning of the face mask as a symbol of individual safety during the two crises. This study analyses news articles to answer three questions: (1) How was wearing the face mask mythologized as a routinized practice in days of uncertain risk? (2) How was the face mask politicized as a mythologized sign indicating China as an external threat? and (3) How was the face mask politicized as a symbolic code of the government’s responsibility for the crisis? Once signified as the primary means of individual protection in the context of Korean risk society, the face mask became politicized amid the shortage of the face mask. Placed in the context of the recent disastrous crises in Korea, China was identified as the culprit not only in the epidemic but also in the shortage of the face mask. The meaning of China as an external threat was continuously strengthened when the South Korean government opted out of the entry ban on Chinese citizens. The last analytic part presents how news media politicized the epidemic by associating the face mask crisis with the Korean government.

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