Acoustic Epidemiology

(WSJ Illustration)

Like my pediatrician nearly 70 years ago, the 21st century doctor still places a stethoscope in several spots on the chest and back, asks me to breathe deeply then normally, and pronounces everything to be fine.

It's familiarly reassuring, yet a little disturbing, that almost everything has changed in medicine except the ritual of interpreting the sounds of respiration through a stethoscope...until now. [bold added]

Researchers around the world are trying to turn the humble cough into an inexpensive tool to diagnose and stop respiratory-disease killers like tuberculosis and Covid-19. They’re collecting recordings of millions of the explosive sounds from patients and consumers on smartphones and other devices. And they’re training artificial intelligence to find patterns to try to identify the type and severity of disease from the cough itself.

“We call it acoustic epidemiology,” says Peter Small, a tuberculosis expert and chief medical officer of Hyfe Inc., a Delaware-based company with two free smartphone apps—one for consumers, another for researchers—that use AI to detect and track how often someone coughs.

The sound and frequency of coughs are rich with medical information, he says. Different diseases have some audible differences: crackling in parts of the lung for pneumonia, a wheezing sound for asthma. Makers of these apps say there are sounds and patterns that AI can detect, but the human ear can’t hear.

The smartphone revolution has allowed researchers to amass databases of respiratory sounds and correlate them with various medical conditions.

ResApp Health Ltd. is using an explosion in telehealth services, particularly during the pandemic, to expand use of an app-based test for cough sounds that helps doctors diagnose diseases including COPD, pneumonia, asthma and bronchitis, says Tony Keating, the Brisbane, Australia-based company’s chief executive. A telehealth provider asks a patient to hold a smartphone at arm’s length and record five coughs. The app analyzes the coughs, then sends the results to the doctor.

Using technology developed by researchers at the University of Queensland, the company built the diagnostic tool by training an algorithm on recordings of 6,000 coughs, along with clinical data from those patients in the U.S. and Australia, Mr. Keating says.

Acoustic epidemiology is in its early stages. No expert would posit that a smartphone app has risen to the level of a medical-grade diagnostic tool, but its value as an initial screening device seems undisputable.

Your humble blogger believes that cough-analysis would be a logical next step for Apple's expansion into health care, but at first blush implementation seems tricky: coughing regularly into one's watch or phone is socially dubious, and putting on a sensing device like a smart bra or undershirt every morning seems like too much trouble. Maybe a famous-designer T-shirt? I'm sure they'll think of something.