Automatic tube compensation mode (ATC) is a newer modality that is especially used in cases of weaning. This mode of ventilation reduces the work of breathing and is especially helpful in cases where the patient in intubated (endotracheal intubation). It is especially used in non-linear, flow dependant drop in pressure in intubated patients. In patient with endotracheal intubation it helps in reducing the resistance during breathing by providing the required pressure to overcome the resistance and also increases the patient's comfort level. ATC (Automatic tube compensation mode) uses the closed loop principle and was associated with increased harmony between the patient and ventilator.