Patent ID: 8770191

Claim:
A system for providing mechanical ventilation support to a patient, the system comprising: a mechanical ventilator configured to pneumatically provide mechanical ventilation support to the patient; a breathing circuit pneumatically connected between the mechanical ventilator and a patient connection configured to deliver the mechanical ventilation support to the patient, wherein the breathing circuit comprises an inspiratory limb upstream of the patient connection and an expiratory limb downstream of the patient connection; an inspiratory check valve disposed within the inspiratory limb of the breathing circuit; a fresh gas manifold configured to provide fresh gas to the breathing circuit for delivery to the patient; a fresh gas valve disposed between the fresh gas manifold and the breathing circuit, the fresh gas valve being operable between at least two positions, wherein in a first position the fresh gas valve directs fresh gas through an upstream conduit that provides the fresh gas to the breathing circuit upstream of the inspiratory check valve, and in a second position the fresh gas valve directs the fresh gas through a downstream conduit that provides the fresh gas to the breathing circuit downstream of the inspiratory check valve; and a digital signal processor that operates the fresh gas valve selectively between the first position and the second position to provide mechanical ventilation support to the patient; wherein the inspiratory limb and the expiratory limb are fluidly connected downstream of the patient and wherein when the fresh gas valve is in the second position fresh gas combines with the expired gas from the expiratory limb downstream of an expiratory check valve.