Ventilator with integrated blower to provide negative or positive pressure in a ventilator system

A method of ventilation, comprising:

• providing an inspiration port (122, 222, 322) configured to be connected to an inspiration limb (112, 212, 312) of a dual-limb patient circuit (110, 210, 310), and providing an expiration port (142, 242, 342) configured to be connected to an expiratory limb (114, 214, 314) of the dual-limb patient circuit;
• supplying a pressurized flow of gas to the inspiration port to generate positive pressure;
• and
• selectively connecting an inlet (132, 232, 332) of a blower (130, 230, 330) to the expiration port to selectively supply a negative pressure level between 4 and 120 cmH2O to the expiration port and to exhaust from an outlet (134, 234, 334) of the blower gas received from the expiration port.

A ventilator system (400), comprising:

• a patient circuit interface port (42) configured to be connected to a single-limb patient circuit (410);
• a gas delivery device (420) operatively connected to the patient circuit interface port and configured to supply a pressurized flow of gas to the patient circuit interface port to generate positive pressure;
• a blower (430) having an outlet (434) operatively connected to the patient circuit interface port and configured to supply a pressurized flow of air to the patient circuit interface port in addition to the pressured flow of gas from primary gas delivery device;
• a pressure transducer (428) configured to measure a gas pressure in the patient circuit;
• at least one flow sensor (424) configured to measure a gas flow in the patient circuit;
• and
• a controller (450) configured to control the gas delivery device and the blower in response to a pressure transducer signal indicating the measured pressure in the patient circuit and a flow sensor signal indicating the measured gas flow from the gas delivery device.