A new wireless and wearable device developed by Northwestern Medicine scientists that can measure specific biomarkers in a person’s sweat has the potential to improve clinical decision-making for cystic fibrosis. Courtesy of Roozbeh Ghaffari, PhD.

A new wireless and wearable device developed by Northwestern Medicine scientists, in collaboration with Northwestern University spinout company, Epicore Biosystems, measures specific biomarkers in a person's sweat with similar accuracy to standard testing methods and has the potential to improve clinical decision-making for cystic fibrosis, as detailed in a recent study published in the Proceedings of the National Academy of Sciences.

Cystic fibrosis is a genetic disease that causes excess mucus to build up in the lungs, impairs digestion and can impact multiple other organs. More than 40, 000 children and adults in the U.S. currently live with cystic fibrosis, according to the Cystic Fibrosis Foundation, and while symptoms can be treated to improve patients' quality of life, the disease is progressive with early mortality.

Sweat chloride tests done in specialized laboratories are the current gold standard for diagnosing cystic fibrosis, detecting increased levels of chloride in a person's sweat, which is caused by mutations in the CFTR gene.

Newly developed CFTR modulator drugs can help improve CFTR protein function, decrease levels of sweat chloride, improve overall symptoms and improve disease trajectory. Optimizing the use of CFTR modulator drugs on a day-to-day basis is a crucial therapeutic goal. However, there are no standard approaches for assessing the efficacy of these drugs outside of clinical settings.

In response, Northwestern Medicine investigators, in collaboration with Epicore Biosystems, developed and evaluated a sticker-like wireless device called the CF patch. The patch, which is worn on a patient's wrist, contains two channels: one measuring sweat volume and the other measuring sweat chloride. An image is taken of the sweat patch using a physician's smartphone or iPad and color changes corresponding to sweat volume and chloride concentrations are analyzed, which could be used to guide clinical decision-making.

"We wanted to see how accurate our CF patch was relative to the gold standard, whether we could do it remotely at home, and then also see how consistent the sweat chloride is in response to the medications (i.e. CFTR modulators). Are sweat chloride levels the same or very similar on a day-to-day basis, or is there a lot of variability on a day-to-day basis that could suggest that maybe these drugs are not working as optimally as they might otherwise?" said Manu Jain, MD, professor of Medicine in the Division of Pulmonary and Critical Care and of Pediatrics, who was senior author of the study.

To test the feasibility and accuracy of the CF patch, 20 adults with cystic fibrosis and seven healthy control participants were recruited to complete a clinic-based chloride sweat test and then five remote exercise sessions for 14 days while wearing the CF patch.

After the study period, the investigators found that CF patch measured sweat chloride in participants as effectively as the standard chloride sweat test done in specialized laboratories.

"This study demonstrates the feasibility and accuracy of a wearable microfluidic sweat patch for remote monitoring of sweat chloride concentrations in individuals with cystic fibrosis, " the authors wrote.

In the next phase of the study, the team aims to determine if the CF patch can help inform clinical decision-making for patients with cystic fibrosis. Jain also added that the patch could expand cystic fibrosis screening and management in rural areas and lower-resourced countries with limited access to diagnostic testing.

"Potentially this could be used as a screening or diagnostic test in parts of the country where sweat testing is not readily available and could expedite the diagnosis of cystic fibrosis, " Jain said.

More information: Rachel S. Nelson et al, Remote analysis and management of sweat biomarkers using a wearable microfluidic sticker in adult cystic fibrosis patients, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2506137122  Journal information: Proceedings of the National Academy of Sciences