Advanced Respiratory Monitoring and Oxygen Therapy in Chronically Ill Patients With Acute Respiratory Failure

This study is testing whether a new type of home oxygen therapy, called high-flow nasal cannula (HFNC), can improve breathing comfort and quality of life for people with long-term lung or heart conditions who need oxygen after leaving the hospital. HFNC delivers warm, humidified oxygen at higher flow rates than standard oxygen therapy, which may reduce shortness of breath, improve sleep, and make daily activities easier. The therapy will be provided using the myAirvo™3 device, which also allows doctors to check patients' oxygen levels, heart rate, and symptoms remotely. All patients will also wear a small device (RootiREX) to monitor heart rhythm, sleep quality, and detect breathing pauses at night. Participants will try both treatments - HFNC and standard oxygen therapy - for short periods, in random order, so that researchers can directly compare the effects within the same patient.