Patent ID: 8267085

Claim:
A method of compensating for leakage in a ventilation system the method performed by the medical ventilator having a processor communicatively coupled to memory, the memory storing instructions that when executed by the processor cause the ventilator to perform the method during delivery of proportional assist ventilation to a patient, the method comprising: monitoring an instantaneous flow in the ventilation system based on one or more measurements of pressure and flow in the ventilation system; modeling by the processor leakage from the ventilation system 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; using the leak-compensated lung flow and a predetermined respiratory mechanics model to estimate a leak-compensated lung compliance and a leak-compensated lung resistance; and calculating a pressure to be delivered to the patient based on the leak-compensated lung flow, the leak-compensated lung compliance and the leak-compensated lung resistance.