Leak-compensated flow triggering and cycling in medical ventilators

A method of compensating for leakage in a ventilation tubing 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;
• estimating compliance and resistance of the ventilation tubing system;
• and
• transitioning the medical ventilator between inhalation and exhalation based on the inelastic leakage, the elastic leakage, the compliance and resistance 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;
• and
• a compensation module that generates a leak-compensated lung flow based on the elastic leakage and at least one output indicative of a pressure of the breathing gas.

A controller for a medical ventilator comprising:

• a microprocessor;
• and
• a lung flow estimation means that adjusts a ventilator net flow threshold based on:
• identifying an instantaneous elastic 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;
• and
• identifying an instantaneous inelastic leakage in the ventilation system as a second function of at least one of a pressure measurement and a flow measurement in the ventilation system.