It has now collected audio of cough recordings from Covid infected people in the US for its clinical study.

ResApp chief executive Tony Keating said the US data as well as data from a clinical study in India provided a high-quality dataset to build, train and validate algorithms for the detection and monitoring of Covid.

“As the fourth wave of Covid-19 spreads worldwide, our team is working hard to deliver algorithms for a much needed, instant smartphone-based screening test and patient monitoring tools that could change the way the world lives with this virus,” Keating said.

The US-based cough pilot clinical study uses what ResApp called the “gold-standard PCR pathology test as a reference standard”.

It has collected cough recording for 122 PCR confirmed cases and 139 negative cases.

ResApp has previously said early CT images from patients in China showed a unique signature in the lungs of many people with Covid-19 and research from the US suggested cough sounds from the lungs may be able to detect an infection.

“What ResApp has to offer here is potentially game-changing … the ability to screen for individuals likely to have Covid-19,” the company recently told shareholders.

It has previously developed an approved smartphone-based respiratory diagnostic test for use in telehealth, emergency department and primary care settings.

It also has a smartphone application for the self-assessment of sleep apnoea and is working with AstraZeneca on an asthma monitoring app.