Recent respiratory disease epidemics have attracted a lot of attention, yet most respiratory monitoring is limited to physical signals. Exhaled breath condensate (EBC) is packed with rich molecular information that can reveal various insights into an individual's health. Now, Professor Wei Gao and colleagues at California Institute of Technology have developed EBCare, a mask-based device that monitors EBC biomarkers in real time. For example, the EBCare mask can monitor asthma patients for their levels of nitrite, a chemical that indicates airway inflammation.
This diagram shows how the smart mask detects breathed chemicals, such as nitrite, an indicator of airway inflammation. Images by Wei Gao and Wenzheng Heng, Caltech.
“Monitoring a patient's breathing is routinely done, for example to assess asthma and other respiratory diseases,” Prof Gao said.
“However, this method requires patients to visit a clinic to have a sample taken and then wait for the test results.”
“Since COVID-19, people have started wearing masks. We can leverage this increased use of masks for remote, personalized monitoring to get real-time feedback on one's health from the comfort of one's own home or office.”
“For example, we could use this information to evaluate how effective a medical treatment is.”
To selectively analyze the chemicals and molecules in your breath, you first need to cool them down and condense them into a liquid.
In a clinical setting, this cooling step is separate from the analysis: Moistbreath samples are cooled in a bucket of ice or a large refrigerated cooler.
The EBCare mask, on the other hand, is self-cooling, according to the team.
The breath is cooled by a passive cooling system that integrates hydrogel evaporative cooling and radiative cooling to effectively cool the breath on the facemask.
“This mask represents a new paradigm for respiratory and metabolic disease management and precision medicine because wearing it daily allows for easy collection of breath samples and real-time analysis of exhaled chemical molecules,” said Wen-zheng Heng, a graduate student at the California Institute of Technology.
“Breath condensate contains soluble gases as well as non-volatile substances in the form of aerosols and droplets, including metabolic products, inflammatory indicators and pathogens.”
Once the breath is converted into liquid, a series of capillaries in a device called bioinspired microfluidics immediately transports the liquid to a sensor for analysis.
“We learned how to transport water from plants, which use capillary action to pull water up from the ground,” Professor Gao said.
“The analysis results are then sent wirelessly to an individual's phone, tablet or computer.”
“The smart mask can be prepared at a relatively low cost. The materials are designed to cost just $1.”
To test the masks, the authors conducted a series of human studies, focusing primarily on patients with asthma or COPD.
The researchers specifically monitored the patients' breath for nitrite, a biomarker of inflammation in both diseases.
Results showed that the masks accurately detected biomarkers indicative of inflammation in patients' airways.
In a separate experiment, the masks demonstrated that they could accurately detect subjects' blood alcohol levels, suggesting that they could potentially be used for field DUI checks and other alcohol consumption monitoring.
We also explored how the mask can be used to assess blood urea levels in the monitoring and management of kidney disease.
As kidney function declines, by-products of protein metabolism, such as urea, accumulate in the blood.
At the same time, the amount of urea in saliva increases, which breaks down into ammonia gas, leading to high ammonium concentrations in the breath condensate.
The study showed that the smart mask could accurately detect ammonium levels, closely reflecting the urea concentration in blood.
“Our smart mask platform for EBC collection and analysis represents a major advancement in the potential for real-time monitoring of lung health,” said Professor Harry Rossiter, director of the Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center.
“This concept, with the potential to add biosensors for a wide range of compounds in the future, highlights the groundbreaking potential of smart masks in health monitoring and diagnostics.”
The team's work is paper In the journal Science.
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Wen-zhen Heng others2024. Smart masks for collection and analysis of exhaled breath condensate. Science 385 (6712): 954-961; doi: 10.1126/science.adn6471
This article is a version of a press release provided by Caltech.
Source: www.sci.news
