Patent ID: 6763829
Filing Date: 2004-07-20
Classification: A61M,Y10T

Abstract:
A method of enhancing reliability of operation of a pressure-actuated airway valve for a breathing circuit, the airway valve having a first mode for permitting air flow substantially directly through the airway valve and a second mode for providing a re-breathing capability to the breathing circuit, comprising:providing a control line extending from a source of pressurized fluid to the airway valve to selectively effect a change in mode of the airway valve between the first mode and the second mode through a change in an actuation pressure provided to the airway valve via the control line; providing a control line valve disposed in the control line between the source of pressurized fluid and the airway valve, wherein the control line valve is configured for selective communication between the control line and an ambient environment; detecting pressure within the control line; and correcting a detected control line pressure deviation from at least one selected magnitude of control line pressure by adjusting the communication between the control line and ambient environment so as to control the actuation pressure applied to the airway valve.