Mechanical ventilation system utilizing bias valve

A method for attenuating a gas flow from a gas source to a patient circuit, comprising:

• connecting a bias valve between the gas source and the patient circuit, the bias valve comprising an inlet connected to the gas source, an outlet connected to the patient circuit, a cavity, and a poppet configured to reciprocate within the cavity;
• engaging the poppet with a valve seat at the bias valve inlet in a closed position and disengaging the poppet from the valve seat in an open position for respectively resisting and allowing gas to flow out of the bias valve outlet;
• and
• viscously dampening the gas flow when the gas passes through a poppet clearance between the poppet and the cavity during poppet reciprocation.

A ventilator system comprising:

• a pulsating gas source;
• a patient circuit;
• an exhalation valve connected to the patient circuit;
• an exhalation control module configured to operate the exhalation valve;
• and
• a bias valve connected between the gas source and the patient circuit, the bias valve comprising an inlet connected to the gas source and comprising a valve seat, and an outlet connected to the patient circuit, a cavity fluidly coupled to the inlet and the outlet, and a poppet configured to reciprocate within the cavity to engage against the valve seat to resist gas flow into the bias valve in a closed position, and disengage from the valve seat to permit gas flow into the bias valve in an open position.