An App for
Breathing Easier


Eric Larson, a lead author on the lung app project from the University of Washington, Seattle Children's Hospital and UW Medicine, was instantly interested in the project because of his passion for engineering that has an impact. "One of the major causes of illness has to do with the lungs," Larson says. "If we can catch a problem early, it can make all the difference. Getting involved with pulmonologists the question became: 'How do you make a low-cost barometer for lung health?'

The first thought as a team involved a mobile microphone. "We wondered if we could do it where you blow into it and something happens on screen," Larson says. "But I wasn't sure if it would be a great sensor of pressure so we'd need to correct the algorithm to make it a stable measurement of someone blowing out of their lung. Once you can do that it relates well to that flow rate for measuring barometry."

Digital Submission

The better part of the first year of the work was spent developing the algorithms. "We went back to the drawing board a lot on what those measurements would entail, what features to pull out of an audio signal—we collected data from 52 different people." What they found is that they could get measurements within 5 percent of the accuracy of commercial instruments.

From a research perspective, what was still unknown was how well consumers could perform the test at home. But Larson quickly saw that the mobile phone can guide people through this concept by digital submission. "It can take you through a test visualization on a smartphone to make sure you're doing the test right or giving your best effort."

SpiroSmart allows users to monitor pulmonary ailments such as asthma, chronic obstructive pulmonary disease, and cystic fibrosis. Image:

FDA Approval

"After we published the paper, it was more about how do we make this something that will be acceptable for the FDA," he says. "We collect third-party data with children then at the end of the month it goes to trials that will be looked at by the FDA. With the first study it was mostly healthy people and mild asthma, next it's doing barometry with varying degrees of asthma."

And pulmonologists have been there through many important steps. "Any time we're creating something it's good to know the needs of the physician to design around it," Larson says. "When doing 12 barometry tests in one and a half hours, a pulmonologist can tell you what fatigue the subject will get or whether they will pass out. You want to be able to watch out for the factors that might cause problems later on."

If it gets approval, the app, dubbed SpiroSmart, can have a large effect on other devices presently used for lung function measure, including the spirometer, which Larson says can cost $3,000. But, beyond the savings, is that it can be done anywhere. "It creates a baseline for lung function blood pressure," Larson says. "For results to be written down weekly and, for a doctor to see the ongoing trend, that can be very beneficial."

Eric Butterman is an independent writer.

“It creates a baseline for lung function blood pressure. For results to be written down weekly and, for a doctor to see the ongoing trend, that can be very beneficial.”

Eric Larson, Lung App Project


March 2013

by Eric Butterman,