Leak-compensated pressure triggering in medical ventilators

A method of compensating for leakage in a ventilation system during delivery of gas from a medical ventilator to a patient comprising:

• identifying an inelastic leakage in the ventilation system as a first function of at least one of a pressure measurement and a flow measurement in the ventilation system;
• identifying an elastic leakage in the ventilation system as a second function of at least one of the pressure measurement and the flow measurement in the ventilation system;
• and
• determining that the patient is initiating an inspiration based on the inelastic leakage, the elastic leakage and the at least one of the pressure measurement and the flow measurement in the ventilation system.

A pressure support system comprising:

• a pressure generating system adapted to generate a flow of breathing gas;
• a ventilation system including a patient interface device;
• one or more sensors operatively coupled to the pressure generating system or the ventilation system, each sensor capable of generating an output indicative of a pressure of the breathing gas;
• a processor;
• an elastic leak estimation module that identifies an elastic leakage in the ventilation system;
• a compensation module that generates a leak-compensated pressure trigger condition based on the elastic leakage and at least one output indicative of a pressure of the breathing gas;
• and
• an inspiration detection module that determines when a patient has begun to inhale based on the leak-compensated pressure trigger condition and an output of at least one sensor.

A controller for a medical ventilator comprising:

• a microprocessor;
• and
• a pressure trigger compensation means for adjusting an initial pressure trigger threshold, based on:
• identifying an elastic leakage in a ventilation system as a first function of at least one of a pressure measurement and a flow measurement in the ventilation system;
• identifying an inelastic leakage in the ventilation system as a second function of at least one of the pressure measurement and the flow measurement in the ventilation system;
• and
• generating a leak-compensated pressure trigger condition based on the initial pressure trigger threshold, the inelastic leakage, the elastic leakage and at least one of the pressure measurement and the flow measurement in the ventilation system.