Patent ID: 8893718

Claim:
A system for ventilating lungs of a subject comprising a gas mixer for supplying a fresh gas for a subject breathing and a breathing circuit for connecting lungs of the subject and the gas mixer, the breathing circuit configured to provide an inspiration gas comprising the fresh gas for the subject breathing, the breathing circuit comprising: a branching unit comprising a Y-piece having at least three limbs, a first of the limbs being an inspiration limb for an inspired gas, the first limb having a first one-way valve to allow the inspired gas through the inspiration limb, a second of the limbs being an expiration limb for an expired gas, the second limb having a second one-way valve to allow the expired gas through the expiration limb, a third limb being a patient limb for carrying both the inspired gas and the expired gas to and from the lungs of a patient; and a valve configured to relieve gaseous pressure in the branching unit, the valve being coupled to one of the Y-piece and the first limb and between the first one-way valve and the patient limb, the valve comprising: an inlet port in flow communication with the branching unit; an outlet port configured to release pressure by discharging a gas flow from the inlet port; a valve seat in flow communication with the inlet port; a valve member configured to close a gas discharge between the inlet port and the outlet port when forced against the valve seat, and to facilitate gas discharge between the inlet port and the outlet port when not forced against the valve seat; a closing spring configured to direct a predetermined closing force to the valve member, wherein the valve member is not forced against the valve seat when a force, due to the gaseous pressure exerted on the valve member when the gas flows from the inlet port to the outlet port, exceeds the predetermined closing force of the closing spring; and an actuator configured to increase and decrease the closing force directed to the valve member; a valve controller configured to control an operation of the actuator, the valve controller being independent of a control unit operating an expiration valve of the second limb of the branching unit; and the closing spring configured to maintain the valve in a closed position when the actuator is inactive allowing manual ventilation through the branching unit in the event of a failure of the valve controller.