Medical technology firm iSonea has launched a device to help asthma sufferers monitor their condition with a smartphone.

The AirSonea device turns a phone into a portable wheeze monitor when held against the windpipe near the base of the throat.

Sounds are transmitted via the smartphone to a cloud-based site to be analysed with iSonea’s acoustic respiratory monitoring technology.

The wheeze rate is then downloaded to the phone.

iSonea says the device enables asthmatics to monitor their wheeze anywhere, anytime, and provides data to help doctors with patient reviews.

Previously, devices called peak flow meters have been available for manual asthma monitoring, but iSonea says the meters require repeated forced breathing efforts that are hard for children and elderly patients.

Reporting of peak flow measurements have also proved unreliable.

iSonea chief executive Michael Thomas described the Australian launch of the AirSonea as a turning point for the company.

“Investors in our company are participating in the most exciting advancement in decades in respiratory mobile health technology,” he said in a statement on Tuesday.

The AirSonea is expected to be launched in the United States in the first quarter of 2014.

Shares in iSonea dropped 3.5 cents to 79.5 cents.