Background： Neurally Adjusted Ventilatory Assist (NAVA) mode is a new mode of ventilator, using electronic potential of diaphragm to adjust tidal volume. At the same time, this mode can trigger and cycle-off inspiratory time by high sensitivity of electronic potential of diaphragm, increase patient-ventilator synchrony, reduce sedative drug, improve oxygenation, shorten mechanical ventilation day and reduce the rate of diaphragm atrophy. It can improve survival rate and hospital day of patients. Both the animal and human experiment have the effect of lung and diaphragm protection Effect： The results of this trial are expected to obtain electronic potential of diaphragm in patients with obstructive pulmonary disease. Reviewing the current literature, few related literatures have such data presentation. This trial hopes to evaluate whether the use of NAVA can reduce mechanical ventilation day by analyzing electronic potential of diaphragm in patients with obstructive pulmonary disease.

Investigators expect that participants with obstructive pulmonary disease using NAVA mode will have significantly less mechanical ventilation day than using conventional mode

Inclusion Criteria:

1. Obstructive pulmonary diseases include chronic obstructive pulmonary disease (COPD), asthma (Asthma), cystic fibrosis (cystic fibrosis), bronchiectasis (bronchiectasis), bronchiolitis or other diseases that cause airway stenosis, etc.
2. Other patients with obstructive pulmonary disease assessed by the clinical team
3. Consent signed by the principal or legal representative
4. Age > 20 years old and < 99 years old

Exclusion Criteria:

1. Those who cannot place a nasogastric tube due to medical conditions
2. Pregnant women
3. Those who have received gas cutting
4. Patients with phrenic nerve palsy
5. Neuromuscular disease
6. Intubation due to cardiac arrest