Asthma is a chronic respiratory disease that affects about 10% of children and adults in the US. Mild to moderate asthma can be difficult to diagnose because symptoms can change over time and can be complicated by other respiratory conditions. Given the high prevalence of asthma, there is high potential impact of improved diagnostic tools on reducing morbidity and mortality from asthma.

Current diagnostic tools for asthma, including spirometry and bronchoscopy, require specialized equipment and expertise to operate properly. Many individuals, particularly young children, have difficulty with pulmonary function testing because