Patent ID: 8272379

Claim:
A method of compensating for leakage in a ventilation system during delivery of gas from a medical ventilator to a patient comprising: monitoring an instantaneous flow at a location in the ventilation system based on one or more measurements of pressure and flow in the ventilation system; modeling leakage as a first leakage component through a first orifice of a fixed size and a second leakage component through a second orifice of a varying size, wherein the first and second leakage components are different functions of instantaneous pressure in the ventilation system; estimating a leak-compensated instantaneous lung flow of gas inhaled or exhaled by the patient based on the one or more measurements, the first leakage component and second leakage component; and using the leak-compensated instantaneous lung flow and a threshold to identify patient-initiated transitions into inhalation or exhalation.