Smartphone Application Helps Monitor Lung Health

By analyzing lip reverberation, the app is capable of monitoring pulmonary ailments such as asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF). The researchers first modeled the trachea and vocal tract as a system of tubes to analyze the sound wave frequencies and detect the resonances that occur in the signal due to airflow passing the trachea and the vocal tract.

The researchers then tested the app on 52 mostly healthy volunteers using an iPhone 4S smartphone and its built-in microphone. The results showed that the SpiroSmart app came within 5.1% of the accuracy of a commercial portable spirometer. Asm such, the results already meet the medical community's standards for accuracy, since natural variation in the effort a patient uses to exhale during each test results in a 3% standard deviation being unavoidable. The study was presented at the Association for Computing Machinery (ACM) international conference on ubiquitous computing, held during September 2012 in Pittsburgh (PA, USA).

“There's a big need in the pulmonary community to make testing cheaper and more convenient,” said lead researcher Shwetak Patel, PhD, an assistant professor of computer science and engineering and of electrical engineering. “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.’”

A spirometer is a precision differential pressure transducer for the measurement of basic pulmonary function tests (PFTs), measuring the volume of air inspired and expired by the lungs over a specified period of time. Lung diseases such as asthma, bronchitis, and emphysema can be ruled out from the tests. In addition, it is often used for finding the cause for shortness of breath, assessing the effects of contaminants on lung functions, effect of medication, and progress for disease treatment.

Related Links:
University of Washington
Seattle Children's Hospital