System and method for providing mechanical ventilation support to a patient

A method of ventilating a patient with a mechanical ventilator pneumatically connected to the patient through a breathing circuit with an inspiratory check valve and a patient connection, the method comprising:

• operating the mechanical ventilator to provide a series of breaths of ventilatory support to the patient;
• introducing a flow of fresh gas into an inspiratory limb of the breathing circuit through a fresh gas valve, the flow of fresh gas being delivered to the patient in the series of breaths of ventilatory support;
• sensing a ventilatory support value with at least one gas sensor disposed within the breathing circuit;
• identifying an operational condition of the breathing circuit with a digital signal processor that receives the sensed ventilatory support value;
• operating the fresh gas valve with the digital signal processor between a first position and a second position, wherein the first position directs the flow of fresh gas into a first conduit that introduces the flow of fresh gas into the inspiratory limb upstream from the inspiratory check valve and the second position directs the flow of fresh gas into a second conduit that introduces the flow of fresh gas into the inspiratory limb downstream from the inspiratory check valve;
• and recirculating expired gases to the patient by fluidly connecting an expiratory limb of the breathing circuit having an expiratory check valve to the inspiratory limb wherein when the fresh gas valve is in the second position the flow of fresh gas combines with the expired gases downstream of the expiratory check valve.

A system for providing mechanical ventilation support to a patient, the system comprising:

• a breathing circuit pneumatically connected to the patient through 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;
• a bellows pneumatically connected to the inspiratory limb and the expiratory limb of the breathing circuit, the bellows receives expired gases from the expiratory limb and releases excess pressure from the breathing circuit through an exhaust valve, the bellows further being connected to a mechanical ventilator that operates the bellows to provide mechanical ventilation support to the patient through the inspiratory limb;
• an inspiratory check valve disposed within the inspiratory limb of the breathing circuit;
• at least one gas sensor disposed within the breathing circuit, the at least one gas sensor measures a ventilation support value from the gases in 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;
• a digital signal processor that receives the at least one ventilation support value from the at least one gas sensor, the digital signal processor determines an operational condition of the breathing circuit from at least one of the ventilation support values and operates the fresh gas valve selectively between the first position and the second position based upon the determined operational condition.