A bi-level positive airway pressure device includes a housing that has a patient port for connecting to an airway of a patient. There is a device (e.g., a nozzle) for generating a positive airway pressure that is directed through a conduit towards the patient port. An exhalation detector includes a nozzle emitting a jet of a gas directed across the conduit and directed at a receptor channel. When exhalation gases flow from the patient port, the jet of gas is deflected. The exhalation detector converts the decrease in the gas pressure into a movement of an occluding member such that when the exhalation gases flow into the conduit from the patient port, the occluding member moves to block the means for generating the positive airway pressure reducing resistance to exhalation by the patient.

A mechanical ventilation system comprises a plurality of ventilation therapy sub-systems. Each of the ventilation therapy sub-systems is adapted to assist a respiratory function of the patient. The system also comprises a detector of the respiratory drive of the patient, an operator interface receiving one or more control parameters, and a main controller. The main controller assigns a therapeutic contribution to each of the ventilation therapy sub-systems based on the respiratory drive of the patient and on the control parameters. The controller modulates the respiratory drive of a patient by controlling each of the plurality of the ventilation therapy sub-systems according to its assigned therapeutic contribution. Distinct ventilation therapy sub-systems may apply negative pressure on the abdomen of the patient, deliver a non-pressurizing inspiratory flow to the patient, or induce a positive pressure in the airways of the patient.

A ventilator, including: a housing; a reservoir within the housing, wherein the reservoir has an internal chamber, an air inlet port, configured to place in fluid communication the internal chamber with atmospheric air, and an oxygen inlet port, configured to place in fluid communication the internal chamber with a source of oxygen; and a primary blower having an air inlet in fluid communication with the internal chamber, and an air outlet configured to be placed in fluid communication with an inspiration tube external of the ventilator housing, wherein the internal chamber presents a volume for gas mixing extending at least between the air inlet port, the oxygen inlet port and the primary blower air inlet, said volume configured for allowing mixing of air entering in the reservoir via the air inlet port with oxygen entering via the oxygen inlet port before any gas reaches the primary blower air inlet.