The ancient Greek physician and philosopher Hippocrates used the art of smell to diagnose disease as long ago as 400 B.C. and was the architect of the theory that disease is caused by “bad smells.”

Fast forward to the Middle Ages, when plague doctors wore scented beaked masks and spectacles to protect themselves from illness. And now, during the current COVID-19 pandemic, where smell again plays a key role in disease detection.

These days, an electronic nose is being used to confirm the presence of COVID-19 in patients, according to a post in ENT & Audiology News.

“More complex odors will be able to be sniffed out as increasingly diverse sensing materials are invented,” writes Jia Yin Tan. “This emerging technology is not only non-invasive, quick and economical but also has the potential to be used as a front-line point-of-care diagnostic tool in the healthcare industry.”

Today’s chemical sensors can be programmed to analyze compounds from exhaled breath or vapors from bodily fluids, according to the story. The technology is able to detect and identify pathogens related to a variety of ENT infections.

The electronic nose recently successfully examined organic compounds in the exhaled breath of patients with COVID-19 to identify the presence of the virus.

That capability makes it possible to test the breath of patients before an elective surgical procedure and easily rule out those who test positive for COVID-19, ENT & Audiology News reports.

Between April and June 2020, the early days of the global pandemic, 219 study participants in the Netherlands, including 57 who were COVID-19 positive, were invited for breath analysis at the same time that a COVID nasal swab was taken. That's according to a study by Anne G W E Wintjens and others published in Surgical Endoscopy.

If the nasal swab was negative, the presence of SARS-CoV-2 antibodies was checked to confirm the negative result. Participants breathed through the device, an Aeonose, which is a portable breath analyzer, for five minutes.

The researchers found that the electronic nose can distinguish COVID-positive from negative patients based on volatile organic compound analysis.