Measuring Lung Mechanics in Patients with COPD Using the REOM Handheld Portable Device

Inclusion Criteria: * Males and females aged ≥40 with COPD, former/current smokers with a ≥10 pack-year smoking history. * Diagnosed with COPD by FEV1/FVC \< 0.7 using standard PFT post-bronchodilator testing, with either 'mild' ('GOLD 1': FEV1 ≥ 80% of predicted value) COPD or 'very severe' ('GOLD 4': FEV1 \< 30% of predicted value) COPD. * Ability to provide informed consent. Exclusion Criteria: * No existing COPD diagnosis * History of co-morbid asthma * Current use of home oxygen * Any acute exacerbation of COPD (AECOPD) experienced within 4 weeks of participation in the study * Chronic respiratory infection * Any contraindication to respiratory testing * Inability to participate in reproducible measurements due to physical or cognitive barrier