Patent ID: 6626175
Filing Date: 2003-09-30
Classification: A61M

Abstract:
A system for providing a flow of gas to a patient comprising:a pressure generating system adapted to provide a flow of gas to a patient responsive to a control signal; a patient circuit having a first end coupled to the pressure generating system and adapted to communicate the flow of gas with an airway of a patient; a flow sensor adapted to measure the flow of gas in the patient circuit and to output a first flow signal indicative thereof; a pressure sensor adapted to measure a pressure of the flow of gas in the patient circuit and to output a first pressure signal indicative thereof; an exhaust assembly adapted to communicate gas from within the patient circuit to ambient atmosphere; and a controller that receives the first flow signal and the first pressure signal and outputs the control signal that controls the flow of gas delivered to the patient circuit by the pressure generating system and, hence, the flow of gas at a patient's airway, wherein the controller detects onset of an inspiratory phase of a patient's breathing cycle for triggering an inspiratory flow of gas based on such a patient's inspiratory effort, which is determined based on a product of a flow related parameter determined from the first flow signal and a pressure related parameter determined from the first pressure signal.