What do masks mask? A study on transdermal CO2 monitoring

Iitani, Kenta; Tyson, Joel; Rao, Samyukta; Ramamurthy, Sai Sathish; Ge, Xudong; Rao, Govind

doi:10.1016/j.medengphy.2021.10.013

Cited by 6 publications

(8 citation statements)

References 38 publications

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“…This variation among individuals precludes the measurement of absolute tcpCO

by mean of a rate-based approach without further improvements of the technique, as demonstrated by several authors who could only report trend analyses of skin CO

exhalation rate, and no rate-based absolute tcpCO

readings [ 319 , 321 , 322 ]. Further still, the recent work of Iitani et al [ 320 ] clearly illustrates the afore-mentioned inter-subject variability with a factor of more than ten between the exhalation rates of two subjects (S2 and S6 on their Figure 4-H). There may be an exception concerning neonates, however, whose exceedingly thin skin may be more homogeneous than that of adults, leading to less variability in their skin CO

exhalation rate, and allowing Chatterjee et al [ 317 ] to demonstrate a significant correlation between skin CO

exhalation rate and tcpCO

.…”

Section: Future Applications To Transcutaneous Monitoringmentioning

confidence: 73%

“…The NDIR track was then dropped until the mid-2010s and the advent of rate-based approaches by the team of Chatterjee, Ge, Iitani et al [ 317 , 318 , 319 , 320 ] at first and by the team of Grangeat et al [ 321 , 322 ] in a second move. If the latter work is insufficiently detailed—especially the explanations concerning the sensing part itself—the former allows for a sound understanding of the rate-based approach.…”

Section: Future Applications To Transcutaneous Monitoringmentioning

confidence: 99%

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Carbon Dioxide Sensing—Biomedical Applications to Human Subjects

Dervieux¹,

Théron

Uhring

2021

Sensors

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Carbon dioxide (CO2) monitoring in human subjects is of crucial importance in medical practice. Transcutaneous monitors based on the Stow-Severinghaus electrode make a good alternative to the painful and risky arterial “blood gases” sampling. Yet, such monitors are not only expensive, but also bulky and continuously drifting, requiring frequent recalibrations by trained medical staff. Aiming at finding alternatives, the full panel of CO2 measurement techniques is thoroughly reviewed. The physicochemical working principle of each sensing technique is given, as well as some typical merit criteria, advantages, and drawbacks. An overview of the main CO2 monitoring methods and sites routinely used in clinical practice is also provided, revealing their constraints and specificities. The reviewed CO2 sensing techniques are then evaluated in view of the latter clinical constraints and transcutaneous sensing coupled to a dye-based fluorescence CO2 sensing seems to offer the best potential for the development of a future non-invasive clinical CO2 monitor.

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“…This variation among individuals precludes the measurement of absolute tcpCO

by mean of a rate-based approach without further improvements of the technique, as demonstrated by several authors who could only report trend analyses of skin CO

exhalation rate, and no rate-based absolute tcpCO

exhalation rate, and allowing Chatterjee et al [ 317 ] to demonstrate a significant correlation between skin CO

exhalation rate and tcpCO

.…”

Section: Future Applications To Transcutaneous Monitoringmentioning

confidence: 73%

Section: Future Applications To Transcutaneous Monitoringmentioning

confidence: 99%

Carbon Dioxide Sensing—Biomedical Applications to Human Subjects

Dervieux¹,

Théron

Uhring

2021

Sensors

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“…This type of flow pattern shows few perturbations and turbulence, and it is typical during normal breathing conditions. In our study, we developed a mathematical model described by Equation (10), where a and b are the rectangular aperture half-lengths and x and y are the base coordinates that define the two laminar profiles intersecting at v max (see Figure 1b). In the model, the velocity profile at entry falls from v max to zero at the internal wall surfaces.…”

Section: Mathematical Analysis Based On Laminar Flow Modelmentioning

confidence: 99%

“…Face masks have different filtration efficiency based on fiber size, morphology (random or ordered structure), pore size, and material weave. Furthermore, air flow velocity and breathing have an impact on filtration efficiency [7][8][9][10]. Therefore, researchers are investigating the fabrication of face masks with high filtration efficiency to decrease the spread of airborne diseases.…”

Section: Introductionmentioning

confidence: 99%

Design and Evaluation of Face Mask Filtration: Mechanisms, Formulas, and Fluid Dynamics Simulations

Pisapia,

Rees,

Rasekh

2024

Applied Sciences

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The global adoption of face masks as a preventive measure against the spread of the SARS-CoV-2 virus (COVID-19) has spurred extensive research into their filtration efficacy. This study begins by elucidating various mechanisms of particle penetration and comparing filtration efficiency formulas with experimental data from prior studies. This is compared to the filtration efficiency experimental measurement developed in our previous study. Moreover, it delves into fluid dynamics simulations to examine different turbulent airflow models. Specifically, it contrasts the airflow velocity distribution of the k-ω and k-ε turbulent flow models with that of a quadrant-based average velocity model developed within this research. Furthermore, the study conducts fluid dynamic simulations to assess airflow profiles for six distinct medical and non-medical face masks. The results underscore substantial disparities among the simulations, emphasising the criticality of employing accurate fluid dynamics models for evaluating airflow patterns during diverse respiratory activities such as breathing, coughing, or sneezing, thereby enhancing environmental health in the realm of infectious disease prevention.

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“…2(a)] similarly to in a previous paper. (21) The experimental protocol involved wearing a nonwoven mask for a predetermined period while working with the room temperature adjusted to 20 or 30 ℃, as shown in Fig. 2(b).…”

Section: Monitoring Intra-oral Temperature Using Mg Thermometermentioning

confidence: 99%