This is a multicenter prospective cohort study designed to develop and validate a multisensor-based real-time monitoring and intelligent early warning model for acute exacerbations in patients with chronic obstructive pulmonary disease receiving home noninvasive positive pressure ventilation.

Eligible participants will be adults with severe COPD and chronic hypercapnic respiratory failure who are receiving or newly initiating home noninvasive positive pressure ventilation. Participants will undergo baseline assessment and follow-up visits at 3, 6, and 12 months. Clinical data, arterial blood gas measurements, pulmonary function, exercise capacity, symptom burden, health-related quality of life, psychological status, home noninvasive ventilation parameters, adherence, device-related adverse events, healthcare utilization, acute exacerbations, hospitalizations, intensive care unit admissions, invasive mechanical ventilation, and mortality will be collected.

Continuous physiological monitoring data, will be used to construct individualized stable baseline values and to identify digital warning signals. Digital warning events will be further adjudicated through symptom confirmation, treatment and healthcare utilization verification, exclusion of alternative explanations, and investigator assessment.

The study aims to establish a longitudinal clinical and physiological dataset for COPD patients receiving home noninvasive ventilation and to evaluate the performance of a multisensor-based early warning model for clinically confirmed acute exacerbations of COPD.

Inclusion Criteria:

• Age 18 years or older.
• Diagnosis of COPD according to GOLD 2026 criteria, with post-bronchodilator FEV1/FVC < 0.70.
• Severe airflow limitation, defined as FEV1 < 50% of predicted value, corresponding to GOLD grade III-IV.
• Chronic hypercapnic respiratory failure, defined as arterial PaCO₂ ≥ 53 mmHg or ≥ 7.0 kPa while breathing room air in a clinically stable state, that is, no acute exacerbation of COPD within at least 4 weeks before enrollment.

Exclusion Criteria:

• Chronic respiratory failure caused by diseases other than COPD, including neuromuscular diseases, chest wall deformity, obstructive sleep apnea, or severe obesity with BMI > 35 kg/m².
• Severe cardiovascular disease, including NYHA class IV heart failure or unstable angina.
• Severe renal disease receiving long-term renal replacement therapy.
• Expected survival of less than 1 year, including active malignancy or end-stage systemic disease.
• Inability to complete the study, including cognitive impairment, psychiatric disease, inability to cooperate with NPPV, inability to use wearable devices, or inability to complete follow-up.
• Refusal to participate in the study or refusal to sign informed consent.

Study participants will be selected from adult patients with severe chronic obstructive pulmonary disease and chronic hypercapnic respiratory failure who are managed at participating clinical centers and who are receiving or newly initiating home noninvasive positive pressure ventilation. The study population will include clinically stable COPD patients with severe airflow limitation and persistent hypercapnia who are suitable for home NPPV follow-up and multisensor real-time monitoring.