 The purpose of the research or knowledge gap this research is designed to fill is to understand the fate of inhaled drug within the lungs of COPD patients. Current inhalers in use were developed to treat asthma, which is predominantly a disease of the large airways, and these inhalers may not be optimal in treating COPD patients which is predominantly a disease of the small airways. Poor delivery of inhaled bronchodilators to the peripheral deep airways may be a major factor limiting the clinical benefit provided by existing devices. The key to successful treatment could be to accurately target inhaled drug to the diseased lung sites, which is the hypothesis that this protocol will test. 