A ventilator system for controlling mechanical ventilation, the ventilator system comprises: one or more processors； a flow and pressure control valve (3), an exhalation valve (4), a flow transducer (5), and a pressure transducer (6) of the ventilator system； and a memory including instructions that, when executed by the one or more processors, cause the one or more processors to: supply, using the ventilator, a breathing gas from a source of gas (11) to an airway connector (10) configured to deliver the breathing gas to an airway of a patient； servo control the flow and pressure control valve (3) and the exhalation valve (4) of the ventilator system to intermittently switch an airway pressure, supplied to the airway connector, between a substantially constant first baseline pressure level and a substantially constant second baseline pressure level； measuring inspiratory flow by the flow transducer (5) positioned downstream from the flow and pressure control valve (3)；detect a spontaneous inspiration effort to cause a drop in a pressure or volume at the airway connector (10) inside a preset trigger time window that immediately precedes a switching event at the end of a preset first period of time in which the breathing gas is to be switched between the first baseline pressure and the second baseline pressure； maintain a baseline pressure at a pressure level in which the inspiration effort was detected by increasing the first period of time by a delay time so that an inspiration-exhalation cycle is completed during the delay time prior to the switching event； and servo control the flow and pressure control valve (3) and the exhalation valve (4) to switch the baseline pressure level after the delay time.
