A ventilator system for controlling mechanical lung ventilation, the system comprising: one or more processors; a flow and pressure control valve, an exhalation valve, a flow transducer, and a pressure transducer 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 a breathing gas from a source of gas to the airway of a patient using the ventilator system; servo control the flow and pressure control valve and the exhalation valve of the ventilator system to intermittently switch the airway pressure of the patient from a substantially constant high baseline pressure level to a substantially constant low baseline pressure and vice-versa such that the patient is able to breathe spontaneously in both high and low baseline pressure levels; measuring inspiratory flow by the flow transducer positioned downstream from the flow and pressure control valve; detect an inspiration effort by the patient inside a trigger time window that immediately precedes a switching event of the intermittently switched airway pressure; characterised in that the instructions further cause the one or more processors to servo control the flow and pressure control valve and the exhalation valve, to maintain a baseline pressure at the level in which the inspiration effort was detected so that the patient can complete the inspiration-exhalation cycle; and servo control the flow and pressure control valve and the exhalation valve to switch the baseline pressure level after a delay time. one or more processors; a flow and pressure control valve, an exhalation valve, a flow transducer, and a pressure transducer 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 a breathing gas from a source of gas to the airway of a patient using the ventilator system; servo control the flow and pressure control valve and the exhalation valve of the ventilator system to intermittently switch the airway pressure of the patient from a substantially constant high baseline pressure level to a substantially constant low baseline pressure and vice-versa such that the patient is able to breathe spontaneously in both high and low baseline pressure levels; measuring inspiratory flow by the flow transducer positioned downstream from the flow and pressure control valve; detect an inspiration effort by the patient inside a trigger time window that immediately precedes a switching event of the intermittently switched airway pressure; characterised in that the instructions further cause the one or more processors to servo control the flow and pressure control valve and the exhalation valve, to maintain a baseline pressure at the level in which the inspiration effort was detected so that the patient can complete the inspiration-exhalation cycle; and servo control the flow and pressure control valve and the exhalation valve to switch the baseline pressure level after a delay time. supply a breathing gas from a source of gas to the airway of a patient using the ventilator system; servo control the flow and pressure control valve and the exhalation valve of the ventilator system to intermittently switch the airway pressure of the patient from a substantially constant high baseline pressure level to a substantially constant low baseline pressure and vice-versa such that the patient is able to breathe spontaneously in both high and low baseline pressure levels; measuring inspiratory flow by the flow transducer positioned downstream from the flow and pressure control valve; detect an inspiration effort by the patient inside a trigger time window that immediately precedes a switching event of the intermittently switched airway pressure; characterised in that the instructions further cause the one or more processors to servo control the flow and pressure control valve and the exhalation valve, to maintain a baseline pressure at the level in which the inspiration effort was detected so that the patient can complete the inspiration-exhalation cycle; and servo control the flow and pressure control valve and the exhalation valve to switch the baseline pressure level after a delay time.