Instead of unpleasant nasal swab tests, Peter van Wees asks participants to step into an airlocked cabin and to scream or sing.

An industrial air purifier collects all the particles emitted, which are then analysed for the virus.

"If you have coronavirus and are infectious and yelling and screaming you are spreading tens of thousands of particles which contain coronavirus," Van Wees said.

Van Wees, a serial entrepreneur, has set up his booth next to a coronavirus testing centre on the outskirts of Amsterdam to try his invention out on people who have just been tested.

"It's always very nice to scream, when nobody can hear you though," said Soraya Assoud, 25, who needed proof of a negative coronavirus test for a trip to Spain.

Van Wees says that although lots of small particles from the person's clothes and breath are detected, an infection shows up as a cluster around the size of the coronavirus.

The process takes about three minutes.

The virus is identified by its size using a nanometre-scale sizing device.

He sees the machine as a potentially useful screening tool at concerts, airports, schools or offices.

Spokesman Geert Westerhuis of the Netherlands' National Institute for Health (RIVM), which is not involved in the project, said it is looking at an array of testing strategies and would welcome a fast, functioning test that was highly accurate.

But "how this apparatus works -- we can't estimate it because we know too little about it," he said.

A breath test requiring the participant to blow into a tube was approved last month by health authorities in Amsterdam but it has not yet been rolled out across the country due to troubles with "false negatives".

Van Wees is working with a private company to marshal evidence for his strategy.

Assoud, on her way to Spain, said either way, the experience in Van Wees's machine had been pleasant.

"I think it's a good way of meditation as well... it's fun!"

Australian Associated Press