Wearing a mask can help stop the spread of viruses such as SARS-CoV-2, but how well it fits will determine how successful it is.
A new sensor developed at MIT could make it much easier to ensure a good face mask fit. The sensor, which measures physical contact between the mask and the wearer’s face, can be applied to any kind of mask. Image Credit: Courtesy of the researchers
There are currently no simple methods for determining how well a mask fits, but a new sensor created at MIT could change that. Any type of mask can be used with the sensor, which detects direct physical contact between the mask and the wearer’s face.
The surgical masks were fitted to male and female test subjects using this sensor, and the researchers discovered that, on average, the masks fit women’s faces far less precisely than men’s.
What we realized by analyzing our collected data from the individuals in the study was that the masks that we use in daily life are not very suitable for female participants.
Canan Dagdeviren, Study Corresponding Author and LG Career Development Professor, Media Arts and Sciences, Massachusetts Institute of Technology
The researchers hope that their sensor will aid individuals in finding masks that better suit them and that designers can utilize it to design masks that fit a wider range of face shapes and sizes. The sensor could also track environmental variables such as humidity and biological indicators, including breathing rates and temperature.
Siqi Zheng, the STL Champion Professor of Urban and Real Estate Sustainability in the Department of Urban Studies and Planning, Tolga Durak, the managing director of MIT’s Environment, Health, and Safety programs, and Dagdeviren’s team collaborated on the study.
The study’s lead author is MIT postdoc Jin-Hoon Kim, and it was published in Nature Electronics on October 20th, 2022.
Fit Quality
Before the COVID-19 epidemic, when mask use was still uncommon, researchers started working on this idea. To gauge the effectiveness of mask use in locations with high levels of air pollution, their initial plan called for sensors to be included inside the masks.
After the pandemic broke out, they understood that such a sensor could have more extensive uses.
The researchers reasoned that since there were so many various types of masks available during the pandemic, this type of sensor would help assist people in selecting the mask that fits them the best.
A device known as a mask fit tester, which assesses the mask fit by contrasting air particle concentrations within and outside of the face mask, is currently the sole means to determine mask fit. However, only specialized institutions such as hospitals have access to this type of apparatus, and they utilize it to assess how well hospital staff members’ masks fit.
The MIT team sought to develop a more portable, user-friendly mask fit measurement tool. The Conformable Decoders group in Dagdeviren’s lab specializes on creating flexible, stretchable electronics that can be sewn into clothing or worn on the skin to pick up bodily signals.
In this project, we wanted to monitor both biological and environmental conditions simultaneously, such as breathing pattern, skin temperature, human activities, temperature and humidity inside the face mask, and the position of the mask, including whether people are wearing it properly or not. We also wanted to check the fit quality.
Jin-Hoon Kim, Study Lead Author and Postdoctoral Research Fellow, Massachusetts Institute of Technology
The researchers developed a tool they refer to as a conformable multimodal sensor face mask (cMaSK) to incorporate their sensors into face masks. A flexible polymer frame that can be reversibly fastened to the interior of any mask, around the edges, contains sensors that monitor a range of characteristics.
The cMaSK features 17 capacitance sensors along its edge to test fit. These sensors can be used to detect if the mask is touching the skin at each of those spots.
Along with sensors for measuring temperature, humidity, and air pressure, the cMaSK interface also incorporates sensors for motion detection, such as speaking and coughing. If the user is moving, the device’s accelerometer can detect it.
All of the sensors are integrated inside polyimide, a biocompatible material frequently seen in stents and other medical implants.
The cMaSK interface was tested by the researchers on a team of five men and five women. The volunteers all donned surgical masks, and the researchers observed the sensor readings as they engaged in various activities like chatting, moving about, and jogging. They also put the sensors through a range of temperature tests.
The researchers developed a machine-learning method to determine the mask fit quality for each participant in the study using the data collected by the capacitance sensors. Due to variations in face size and shape, these measurements showed that women had significantly poorer mask fits than males.
Women’s fit might be marginally improved, though, by using smaller surgical masks. The researchers discovered that one of the male patients had a beard, which resulted in poor mask fit quality and gaps between the skin and the mask.
The fit results for each study participant were extremely similar to what the researchers discovered using the cMaSK, so the researchers also worked with MIT’s Environment, Health, and Safety Office on the design and evaluation of the fit to confirm their findings.
Customized Fit
The researchers hope their findings will motivate mask manufacturers to create masks that accommodate a range of face sizes and shapes, particularly those of women. The cMaSK interface will be produced in bulk and deployed widely by Dagdeviren’s lab.
Dagdeviren added, “We hope to think about ways to design masks and come up with the best fit for individuals. We have different sizes for shoes, and you can even customize your shoes. So why can’t you customize and design your mask, for your own health and for societal benefit?”
The researchers also want to pursue their initial plan of researching how air pollution affects those who work outside.
Our technology can really help to quantify the social costs of these environmental hazards, and also to measure the benefits of any kind of policy intervention.
Siqi Zheng, Professor, Urban and Real Estate Sustainability, Department of Urban Studies and Planning, Massachusetts Institute of Technology
The study was supported by the 3M Non-Tenured Faculty Award, the MIT International Science and Technology Initiative (MISTI) Global Fund, and the MIT Media Lab Consortium.
Journal Reference:
Kim, J.-H., et al. (2022) A conformable sensory face mask for decoding biological and environmental signals. Nature Electronics. doi:10.1038/s41928-022-00851-6
Source: https://web.mit.edu/