Researchers have created a prototype for an innovative smart mask designed to keep track of various health conditions, particularly respiratory issues like asthma, COPD (chronic obstructive pulmonary disease), and complications following COVID-19 infections.
Wearable health devices are becoming increasingly popular. From smartwatches to health-tracking patches, these advanced gadgets can monitor aspects like heart function and inflammation levels, allowing patients to manage their health conveniently from home. Now, there’s a new addition to this trend: a sophisticated paper mask that tracks breathing patterns.
Wei Gao, a professor of medical engineering at Caltech, and his research team have developed a smart mask that can assess several health conditions, especially respiratory ones such as asthma, COPD, and post-COVID-19 complications. Unlike existing smart masks that track changes in temperature, humidity, or breathing rate, this mask, named EBCare, can analyze the chemical composition of exhaled breath in real-time. The term “EBC” stands for “exhaled breath condensate,” and the mask can, for instance, detect nitrite levels in asthma patients, indicating airway inflammation.
“Breath analysis is a standard practice for evaluating conditions like asthma, but it typically requires a clinic visit for sample collection and lab result waiting,” explains Gao, the leading researcher in a new study published in the journal Science. “With the increased use of masks due to COVID-19, we can utilize this trend for remote health monitoring, providing real-time health feedback from the comfort of our home or workplace. This data could help gauge the effectiveness of medical treatments.”
Gao, who is also affiliated with the Heritage Medical Research Institute and serves as a Ronald and JoAnne Willens Scholar, has previously created various wearable biosensors that analyze sweat for metabolites, nutrients, hormones, and proteins. This time, his focus was on monitoring breath, which presented unique challenges.
To effectively analyze the chemicals in someone’s breath, it first needs to be cooled and converted into a liquid. Typically, this cooling occurs separately from the analysis process using buckets of ice or large refrigerated coolers in clinical settings. However, Gao’s mask employs a self-cooling mechanism. It cools breath using a passive system that combines hydrogel evaporative and radiative cooling, allowing it to chill the breath efficiently as users wear the mask.
“This mask signifies a breakthrough in managing respiratory and metabolic diseases and personalized medicine by enabling the collection of breath samples and real-time chemical analysis through daily-use masks,” states Wenzheng Heng, the study’s lead author and a graduate student at Caltech. “Breath condensate comprises both soluble gases and nonvolatile compounds in aerosol or droplet forms—these include metabolic markers, inflammatory signals, and pathogens.”
Once breath is liquefied, it travels through a series of capillaries—devices inspired by nature—to sensors for analysis. “We learned from plants, which use capillary action to pull water up from the ground,” Gao notes.
The analysis results are then wirelessly sent to a smartphone, tablet, or computer. “The smart mask can be produced at a low cost,” Gao adds. “The materials needed are estimated to be about $1.”
To evaluate the masks, the team conducted studies involving human participants, mainly focusing on individuals with asthma or COPD. They specifically checked for nitrite levels, a biomarker indicative of inflammation in these conditions, finding that the masks effectively identified this biomarker.
In another study, the research team validated that the masks could accurately detect blood alcohol levels in participants, indicating potential uses in monitoring alcohol consumption or conducting roadside sobriety checks.
The researchers also explored how the masks might assess blood urea levels to aid in managing kidney disease. As kidney function declines, waste products like urea accumulate in the bloodstream, which subsequently elevates ammonia levels in breath condensate. The new study found that the smart masks could reliably detect these ammonium levels, closely correlating them with blood urea levels.
“These initial findings serve as proof of concept,” Gao remarks. “We aim to broaden this technology to include various markers associated with different health conditions, laying the groundwork for a versatile health-monitoring mask.”
Participants reported positive experiences regarding the comfort of the masks, including those with existing breathing difficulties.
“The smart mask for harvesting and analyzing exhaled breath condensate marks a significant advancement in real-time lung health monitoring,” declares co-author Harry Rossiter, a researcher at the Lundquist Institute for Biomedical Innovation at Harbor-UCLA and a professor of medicine at the David Geffen School of Medicine at UCLA. “This concept highlights the transformative potential of smart masks for health monitoring and diagnostics, especially with the possibility of integrating biosensors capable of detecting a wide array of compounds in the future.”
The study titled “A smart mask for exhaled breath condensate harvesting and analysis” was made possible through funding from the National Institutes of Health, the National Science Foundation, the Tobacco Related Disease Research Program, and the U.S. Army Medical Research Acquisition Activity. Other contributors from Caltech include graduate students Shukun (Kevin) Yin, Canran Wang, Hong Han, Jiahong Li, and postdoc Jihong Min, along with former postdocs Ehsan Shirzaei Sani and Yu Song.
