A breathalyzer for sleep apnea diagnosis

Last summer in Vienna, Austria, Engineering Professor Perena Gouma delivered a plenary talk at the International Meeting on Chemical Sensors (IMCS) on a sleep apnea sensor. This summer her findings were featured in the American Chemical Society Bulletin.

With a joint appointment in the Department of Materials Science and Engineering and the Department of Mechanical and Aerospace Engineering, Gouma's professional journey at Ohio State has allowed her to interact across disciplines with colleagues in the College of Medicine, particularly those specializing in pulmonary diseases and sleep medicine. "It became apparent to me that my isoprene sensor could be used on its own as an indicator of sleep disorders, particularly sleep apnea," she said. 

Isoprene is one of hundreds of organic compounds in human exhaled breath. Based on medical literature and conversations with her medical colleagues, Gouma proposed that breath isoprene could be a biomarker signaling wakefulness.

According to the National Sleep Foundation, more than 18 million American adults have sleep apnea, a disorder in which breathing is briefly and repeatedly interrupted during sleep. It can cause fragmented sleep and low blood oxygen levels. For people with sleep apnea, the combination of disturbed sleep and oxygen starvation may lead to hypertension, heart disease and mood and memory problems.

Gouma used hexagonal tungsten trioxide as the sensing element, which demonstrated the ability to detect and discriminate among various isoprene concentrations in the range of 300 ppb to 1 ppm and above-the range of interest for the targeted application.

A previous study conducted by the Institute for Breath Research in Austria revealed that healthy adults who are awake have an isoprene level of 1.43 ppm. When asleep, their isoprene levels increased to 3 ppm or more. The fast response, high sensitivity, and noninvasive nature of Gouma's isoprene detector suggests that it can potentially be used as a diagnostic tool for sleep apnea. 

Elected to the National Academy of Inventors in 2016, Gouma has authored or co-authored over 130 articles in peer-reviewed journals and has 18 patents involving nanomaterials, photocatalysts, sensors, and breathalyzers.

with contributions from Dept. of Materials Science and Engineering