A Prospective Observational Study of the Breath Responsive Variable Bolus Oxygen Conserving Device

* Evaluate subjects in an prospective observational study * Subjects will be administered scientifically validated questionnaires * Evaluate Quality Improvement and Oxygen Utilization Improvements. 1\. Functional capability, dyspnea, oxygen saturation as primary endpoints 1. Baseline Dyspnea Index (BDI) 2. Transitional Dyspnea Index (TDI) 3. Chronic Respiratory Disease Questionnaire (CRQ) 4. Six minute walk distance (6MWD) 5. Oxygen saturation using pulse oximeter * The secondary endpoints: 1. Portable oxygen source utilization 2. Health care utilization (emergency room encounters, hospital admissions)