Chronic Obstructive Pulmonary Disease (COPD) is a progressive and irreversible airway obstruction disease. Patients frequently experience dyspnea, sputum retention, repeated exacerbations, reduced exercise tolerance, poor sleep quality, and depressive symptoms. Traditional pulmonary rehabilitation is largely hospital-based and limited by patient age, comorbidities, transportation barriers, and healthcare resource constraints. Active Cycle of Breathing Technique (ACBT) is a non-invasive, low-cost structured breathing method comprising three phases: breathing control, thoracic expansion exercises, and forced expiration technique. Oscillatory Positive Expiratory Pressure (O-PEP) uses a tube valve device to generate oscillatory airflow and positive pressure during expiration, facilitating airway secretion mobilization and clearance. This study adopts a block-randomized crossover design. Group A receives ACBT combined with O-PEP during Weeks 1-8, then standard care during Weeks 9-16. Group B receives standard care during Weeks 1-8, then ACBT combined with O-PEP during Weeks 9-16. Intervention consists of 3 ACBT cycles followed by 10-15 O-PEP expirations, twice daily (at least 8 hours apart), for 8 weeks. All participants receive one-on-one standardized training prior to intervention, with weekly remote follow-up. The O-PEP device will be collected from Group A after Week 8 to prevent carryover. Standard care includes disease education, smoking cessation, self-management skills, and conventional breathing exercises. Data analysis will use Generalized Estimating Equations (GEE) following Intention-to-Treat (ITT) principles.
