Causes of mechanical ventilation: COPD accounts for 30.30% in the NAVA group, 34.38% in the PSV group Mechanical extubation through the endotracheal tube accounted for 57.58% in the NAVA group, 68.75% in the PSV group There was no difference in the causes of mechanical ventilation, endotracheal mechanical ventilation, and mechanical ventilation with tracheostomy canun; p> 0.05.