WearME-Pro Phase II: Remote Use Usability and Longitudinal Validation Study (Patch Form Factor).

Inclusion Criteria: * Age 21 years or older, either sex. * Diagnosed with COPD per GOLD criteria (GOLD 2025): post-bronchodilator FEV1/FVC \< 0.70; stratified by post-bronchodilator FEV1% predicted (severity strata). * On stable maintenance therapy for at least 2 months (no COPD medication class changes or dose escalations). * Current, former, or never smoker (smoking history collected but not an eligibility requirement). * Able to perform activities of daily living and complete study procedures (e.g., sit upright and perform spirometry maneuvers). * Able and willing to provide informed consent. * Not currently enrolled in another investigational device study that could confound outcomes (prior WearME-Basic Phase I participation permitted if completed and not concurrent). * Owns a compatible smartphone/tablet or willing to use a loaner device. * Willing to wear WearME-Pro patch and perform daily handheld spirometry throughout the study. * Optional subset only: willing to wear Cardea SOLO ECG patch for up to 24-48 hours at baseline and end of study if selected. Exclusion Criteria: * COPD exacerbation within past 6 weeks requiring systemic corticosteroids and/or antibiotics, urgent/ED visit, or hospitalization. * Known allergy or severe skin sensitivity to medical adhesives, or dermatologic conditions at intended placement sites. * Any condition that, in the investigator's opinion, may interfere with compliance or safety. * Inability or unwillingness to perform daily spirome…