Wrist-Worn Sweat Sensor Provides Early Warning of Cytokine Storms Caused by COVID-19

A team of researchers from the University of Texas and EnliSense have presented a wrist-worn sensor, which they say can act as an early warning for an impending cytokine storm caused by COVID-19 or other illnesses — by analyzing the wearer's sweat.

"Especially now in the context of COVID-19, if you could monitor pro-inflammatory cytokines and see them trending upwards," says principal investigator Dr. Shalini Prasad of the potential impact of the sensor developed by the team, "you could treat patients early, even before they develop symptoms."

A cytokine storm is a surge of pro-inflammatory immune proteins caused by a range of illnesses including influenza and COVID-19. Early treatment is key to prevent organ damage, and the wrist-worn sweat sensor assists in that — by working around one key problem. "When it comes to cytokines, we found that you have to measure them in passive sweat," Prasad notes. "But the big challenge is that we don't sweat much, especially in air-conditioned environment."

Building on earlier work in monitoring inflammatory bowel disease, the team built the sensor in a way that allows it to operate on the smallest amount of sweat. When the disposable sensor strip reacts with the sweat, an electronic reader built into the watch transmits its findings to a connected smartphone — and its readings agree with cytokine levels found through traditional serum analysis.

Designed to be comfortable enough for long-term monitoring, the sensor - dubbed the SWEATSENSER Dx — has been proven to operate for up to 168 hours, after which the sensor strip, which is coated in antibodies designed to react with pro-inflammatory proteins found in sweat, is replaced to allow for another uninterrupted monitoring period.

While the system shows promise, it has yet to be tested against COVID-19 specifically. "Access to COVID-19 patients has been a challenge because healthcare workers are overwhelmed and don't have time to test investigational devices," Prasad explains. "But we're going to continue to test it for all respiratory infections because the disease trigger itself doesn't matter - it's what's happening with the cytokines that we're interested in monitoring."

The team's work was presented at the American Chemical Society (ACS) Spring 2021 meeting earlier this month. EnliSense, meanwhile, is working to commercialise the technology.