It is based on a cylindrical valve body (1) comprising two chambers, namely a high-pressure chamber (3) and a low-pressure chamber (4) which are separated by a partition (2) that is traversed by a shaft (7), the two ends of which are topped with pistons (5 and 6) which move inside the respective chambers (3) and (4), such that upon receiving gas at a suitable pressure, the piston (5) in the high-pressure chamber (3) moves such as to pull the other piston (6) against a spring (8), thereby pulling the piston (6) which is disposed between the inlet (10) for the gas from the respirator and the gas outlet (11) to the patient, so as to provide a very short closure time as well as a hermetic closure during the interruption. The passage of air from the high-pressure source to the high-pressure chamber (3) is controlled by a servo-assisted solenoid valve which is in turn controlled by a computer or an autonomous electronic device.
