Covid 19 coronavirus: 'Electronic nose' can sniff out virus from infected people's breath

A man breathes into the the PEN3 eNose at trials of the equipment in Tel Aviv, Israel. Photo / Weizmann Institute

An "electronic nose" capable of detecting the "body odour" of Covid from the exhaled breath of an infected person has been built by scientists in Israel.

The technology sees a person breathe into a 3D printed plastic device for 80 seconds, with volatile organic compounds in the inner nasal passage analysed for Covid particles. Developers claim the technology is up to 94 per cent accurate.

Scientists started building the device – called the PEN3 eNose – at the start of the pandemic last year and have published their findings in the peer-reviewed journal Plos One.

Project leader Prof Noam Sobel, from the Weizmann Institute of Science, said: "The e-nose generates a pattern in every odour – it characterises the smell of Covid-19. We are teaching it to smell coronavirus."

Pen3 pumps the samples through various filters and into 10 different sensors, searching for a unique olfactory signal.

"When a compound interacts with the sensors, this results in an oxygen exchange that leads to a change in electrical conductivity," Sobel said.

Noam Sobel - Sniffing out Covid-19 from Weizmann Institute on Vimeo.

A total of 503 people who went for a standard Covid test at a drive-through testing station in Tel Aviv organised by Israel's Red Cross were recruited for the study.

The team got safety assurance from the Israeli Ministry of Health before 3D-printing the devices that were used once on each participant before being disposed of.

Each volunteer provided an electronic nose sample as well as a standard PCR test, and 27 of them were found to be positive for Covid.

Twenty-six of the samples were used to teach the machine how to spot Covid, and the machine was then tasked with spotting the 27th case.

Professor Sobel said: "It was a shot in the dark – but the payback will be so huge. We get an answer in 80 seconds. We are obtaining meaningful data.

"We are actually measuring differences between people. We are gaining information that may open a path to rapid diagnosis.

"Given our current results, an optimised eNose may be able to provide effective real-time diagnoses in locations such as airports, the workplace and cultural events."