In assist mode, how does the Ventilator detect a spontaneous breath from the patient?

The X-VENT uses a configurable pressure threshold to detect a breath from the patient.

In order for a patient to trigger a spontaneous breath, the breath attempt must meet 4 conditions:

1. Expiratory time must exceed inspiratory time set point.
2. Expiratory pressure must be within +0.3/-0.1 cmH2O of PEEP setting.
3. The difference between measured inspiratory and expiratory tidal volumes must not exceed 20 mL.
4. Expiratory flow must be less than 6L/min (100 mL/s).