Brisbane, Australia-based ResApp Health, a digital health company that specializes in diagnosing respiratory diseases, is now conducting clinical proof-of-concept studies for its latest technology that uses a smartphone to detects sleep apnea by sound.

Preliminary results from a clinical trial released by ResApp found that the technology achieved an 86 percent sensitivity and 83 percent specificity for identifying patients with moderate and severe sleep apnea. 

“We are very excited about these excellent preliminary results for identifying [obstructive sleep apnea],” Tony Keating, CEO and managing director of ResApp, said in a statement. “There is a strong clinical and economic need for reducing the number of undiagnosed sleep apnea sufferers, and by utilizing a smartphone we have the opportunity to deliver a highly-scalable, accurate, and easy-to-use screening test to the mass market. By leveraging our expertise in using audio signatures to identify respiratory conditions we have created another large commercial opportunity.”

The company is working with physicians to recruit patients at Hollywood Private Hospital and The Park Private Hospital in Perth Australia for the ongoing trial. 

The technology uses a machine-learning algorithm to detect the severity of sleep apnea by the sound of a person's breathing and snoring. A user can put the smartphone next to their bed and it will record their sleeping. 

Sleep apnea is a common disorder that is often not diagnosed, according to the company. Citing the Wisconsin Sleep Cohort Study, he startup said the condition affects more than three in 10 men and two in 10 women.

ResApp Health has been working on software for smartphones that can diagnose respiratory conditions from the sound signatures of coughs as well. The app uses the smartphone’s microphone-like stethoscope to listen to a patient’s breathing. Instead of relying only on a doctor’s ears to form a diagnosis from the sounds, it uses a machine-learning algorithm that will automatically determine which respiratory condition the patient might have. 

However, last year the company faced a major setback after the data that came back from its landmark clinical trial, conducted at major institutions like Massachusetts General Hospital, Cleveland Clinic, and Texas Children’s Hospital, was proclaimed useless due to “procedural anomalies.”
 
While the company will have to re-do its US trail, in December it announced clinical trial results from its Australian clinical trial. This trial found that the app had 90 percent accuracy when diagnosing a range of respiratory conditions. 

Sleep apnea has been a hot topic in digital health recently, with big names in the industry starting to take notice. In fact, a recent study presented at the American Heart Association showed that when Cardiogram is integrated with the Apple Watch the technology could detect sleep apnea.