Neurally Adjusted Ventilatory Assist (NAVA) is a new form of partial support wherein the machine applies positive pressure throughout inspiration in proportion to the Electrical Activity of the diaphragm (EAdi), as assessed by trans-esophageal electromyography. Because ventilator functioning and cycling are under control of the patient's respiratory drive and rhythm, NAVA has the potential to enhance patient-ventilator interaction ensuring synchrony and minimizing the risk of over-assistance. A high incidence of asynchrony events has been demonstrated to have a significant clinical impact by favouring weaning failure and longer duration of mechanical ventilation.