Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Observational
Official Title: An Investigation Into the Pressure and Airflow/Volume Changes Which Accompany Partial Closure of the Larynx During Expiration in Patients With COPD and the Effect of Applying a Positive End Expired Pr
Brief Summary: In this study the investigators aim to investigate the extent to which in patients with chronic obstructive pulmonary disease narrowing of the vocal cords causes a positive pressure within the airways thus improving airflow and lung function. This information will be captured in the upright and lying down positions and an estimate of the magnitude of the effect will be formed by offsetting the pressure by asking the patients to breathe using a commercially available device used to treat sleep apnoea called a CPAP machine. This is an observational study in which the observation of laryngeal aperture, and mouth and oesophageal pressure at differing levels of applied CPAP will be recorded for analysis in patients with COPD and in normal subjects without COPD. All will have the same measurements, observations, and interventions to allow us to observe and measure pressure, laryngeal aperture, and airflow .