Patent ID: 7201166
Filing Date: 2007-04-10
Classification: A61M

Abstract:
1. An injection system for the delivery of a gaseous substance from a container to a patient through a conduit coupled to the patient's respiratory system; said injection system comprising: a control unit controlling said injection system; a valve assembly in connection with the conduit to selectively allow the delivery of the gaseous substance from the container to the conduit; said valve assembly including a valve and valve actuating means allowing variable opening of said valve; said valve actuating means being coupled to said control unit to be controlled thereby; and a flowmeter quantitatively measuring inspiratory gas flow in the conduit; said flowmeter being coupled to said control unit to supply inspiratory gas flow data thereto; wherein a) said control unit controls unit is so configured as to receive and analyse said inspiratory gas flow data and as to control said valve assembly so that said variable opening of said valve is responsive to said inspiratory gas flow in the conduit so as to achieve a predetermined concentration of the gaseous substance with respect to the inspiratory gas, b) said control unit is so configured as to vary said predetermined concentration within a plurality of inspiratory phases of the patient on the basis of said inspiratory gas flow data, and said control unit opens said valve in response to said inspiratory gas flow when said inspiratory gas flow exceeds a predetermined threshold level; said injection system therefore delivering the gaseous substance only when the patient is in an inspiratory phase and said control unit includes an alarm actuated when a duration of an inspiratory phase exceeds a predetermined duration limit.