Non-invasive Neurally Adjusted Ventilatory Assist

Inclusion Criteria: * Age 18 - 85 years * History of chronic obstructive lung disease * Invasive mechanical ventilation for more than 12 hours * Planned extubation according to the weaning protocol of our clinic * Informed consent obtained from a next of kin * Enrollment approval from a neutral physician neither participating in the study nor in the clinical treatment of the patient Exclusion Criteria: * Tracheostomy * Facial or cranial trauma or surgery * Oral, esophageal, diaphragmatic or gastric trauma or surgery * Contraindication to insertion of a nasogastric tube (e. g. malformation, esophageal varices, esophageal perforation or rupture, Zenkers diverticulum, severe bleeding disorder) * Uncooperative state and combativeness not responding to low levels of sedatives * Neurological disease possibly influencing the brainstem respiratory centre, such as but not limited to: intracerebral, subarachnoidal or subdural hemorrhage, cerebral infarction, possible hypoxic encephalopathy * Next of kin refuses informed consent * Pregnancy. In female patients between 18 and 60 years of age, a pregnancy test will be performed.