University of Washington researchers have developed a way to monitor common lung ailments such as asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis using the existing microphone in a smartphone.
In tests with 52 subjects, the system's accuracy came within 5.1 percent of those you'd find at the doctor's office. And if the device were calibrated to a specific person, that accuracy could be improved, the researchers said.
"There's a big need in the pulmonary community to make testing cheaper and more convenient," lead researcher Shwetak Patel says in a university announcement. "Other people have been working on attachments for the mobile phone that you can blow into. We said, 'Let's just try to figure out how to do it with the microphone that's already there.'"
The school worked with pulmonary specialists from the university medical school and Seattle Children's Hospital on the project. Their research was presented this month at the Association for Computing Machinery's International Conference on Ubiquitous Computing.
While portable spirometers exist to measure patients' lung function, they cost between $1,000 and $4,000, and are far bulkier than a pocket-sized phone. The iPhone, the device of choice for this research, can be free for customers of some carriers' data plans.The researchers envision their app, called SpiroSmart, being low-cost, too.
For the two-and-a-half-year project, researchers first modeled the air going through a patient's trachea and vocal tract using a set of tubes, then analyzed the sound frequencies. Next, they tested their application on humans with no or mild lung conditions. They found the device effective for diagnosing not only abnormal lung function, but also the degree of obstruction using common measures.
The device requires only that the subject find a quiet spot, hold the phone at arm's length and breathe into it. No special training is required beyond that given to patients who use a spirometer.
Current smartphones, however, lack the ability to do all the necessary analysis in real time, requiring that it be done offline or in the cloud. The researchers foresee, however, future phones being able to handle the extra workload within the device. They're working to make monitoring part of a game to improve patient adherence, according to an overview.
Medical device company iSonea is working on similar technology with wireless/mobile company Qualcomm to create apps for asthma patients. The duo are creating a smartphone platform for iSonea's acoustic respiratory monitoring device, WheezoMeter.
And the University of California Los Angeles and eResearchTechnology, Inc. are involved in a year-long program to determine whether remote monitoring can effectively address problems earlier for patients with COPD.