Tracking Lung Health With a Cell Phone

Today, a deep sigh at your smartphone could reveal a well-developed emotional connection with your gadget. But one day those sighs could tip off your doctor to a latent or worsening lung condition.

A group at the University of Washington, in collaboration with Seattle Children’s Hospital, is developing a way to check how healthy your lungs are when you breathe out at your smartphone. 

For patients with conditions like asthma, chronic bronchitis, or cystic fibrosis doctors sound out their pipes using a spirometer, a device that measures volumes of air breathed in and out. The exhaled volume indicates if the patient’s air passages are clogged and leading to difficulty breathing.  

Recently, a group at Shwetak Patel’s lab at the University of Washington figured out how to measure exhaled breaths using the microphone on a smartphone.

The SpiroSmart app estimates the volume of air exhaled by the sound waves recorded as you breathe out. The goal was to create a home lung health test, like a pocket glucose meter, Patel explained in a press release.  In experiments with the iPhone 4S, the system seemed reliable and comparable to home spirometry tests. The group presented that at the UbiComp 2012 conference in September last year.

The team is now adapting this concept—reading lung function from recorded audio of deep breaths out—to create a system that could turn any phone into a reliable indicator of lung function.

SpiroCall, as the team is calling the setup, involves dialing a number and leaving a long breath of air as a voice message on a server. In very early tests, the team found that phone lines preserved enough audio quality for the recorded exhalation to be used as a spirometric substitute. This indicates that any phone, even basic cellphones that are common in developing countries, could be used to remotely measure lung health or detect signs of lung disease.

The authors presented a poster describing their work at the ACM’s Dev 2013 conference in Bangalore last week. In it they suggest that results of the breathing test could be relayed back to the patient by text message. But it’s early days yet—these results only indicate that such a system does make sense to set up, Mayank Goel, one of the authors on the project wrote to me in an email. SpiroCall has several phases of development and a battery of tests planned for it in the months ahead.