Determination of the Prevalence and Severity of Expiratory Flow Limitation in Chronic Obstructive Pulmonary Disease Patients

This will be a cross-sectional, non-randomized epidemiology study designed to assess the prevalence and severity of expiratory flow limitation in a community COPD population. In the study we will also investigate how the presence EFL may correlate to other physiological biomarker endpoints in the COPD patient. Schedule of Events: Study Visit * Once the participant arrives, the study will be explained in full detail. If the participant agrees, he/she will be consented into the study and the participant will be given a copy of the informed consent. * Once consent is obtained, and eligibility is confirmed the following study related procedures will be conducted: * Demographics: gender, date of birth, ethnicity, race, level of education will be collected. * Current Medications: all current medications will be collected. * Medical History Assessment: information will be collected regarding historical spirometry data, COPD history and other relevant medical history including the diagnosis of Sleep disordered breathing and Oxygen therapy usage. Chest computerized tomography (CT) scans will be collected if they have not been done within the past two years. A new CT scan will not be required. * Physical examination with anthropometric data (weight, height and temperature) collected and vital signs to include Heart Rate (HR),Blood Pressure (BP), Respiratory Rate (RR), and Oxygen Saturation (SPO2) maintained at least 88% on room air, and chest auscultation. * Review of inclusion/exclusion to ensure participant is eligible to continue * Administration of Study Questionnaires * Mask Fitting: Participants will have up to two mask fittings in order to determine the best possible masks while using the Vector NIV device during the EFL screening and titration. * Spirometry testing will be performed for participants who have not had a test in the previous 6 months Resmon Pro EFL Measurement * Participants will be required to wear nose clips during the measurement * Participants will also be required to hold their cheeks during the measurement to prevent any air leaks around their mouth. * While seated, participants will be instructed to breathe normally into the device for at least 30 seconds or until at least 10 breaths were successfully accepted by the device * Participants will be asked to repeat test while in the supine or semi-recumbent position. Vector EFL Screening/Determination and EPAP Titration * EFL Determination: The participant will be asked to breathe quietly into the Vector device using the selected mask for 5 minutes in the seated position, and then an additional 5 minutes while in supine or semi-recumbent position. This device has the capability of detecting EFL. If it is determined that the participant does not have EFL by the device screening indicator, the participant will not continue with the EPAP titration. * EPAP Titration: if it is determined by the Vector NIV device that the participant has EFL, the Vector NIV device will be changed from screening mode to therapy mode to delivery BiPAP therapy with the following settings. Vector Device Settings: * Pressure Support 6 cmH2O * Max Pressure 26 cmH2O * EPAP Min / EPAP Max 4 / 20 cmH2O * The participants will then breathe on the Vector NIV device in the supine position (preferred) or semi-recumbent if needed for approximately an additional 20 minutes. During the additional 20 minutes of breathing, the device will automatically increase the EPAP (and concurrently and proportionally the IPAP) until the EFL is abolished (or falls below the predetermined EFL threshold). * While the automatic EPAP Titration is being performed, all participants' SpO2 will be monitored via finger pulse oximetry. * Patient must stay awake during the EPAP Titration. If the patient falls asleep, they will be woken by study staff. * The Final EPAP that is determined to abolish the participants EFL will be recorded * Participants will complete an EFL Vector device post questionnaire