System and method for circuit compliance compensated volume assured pressure control in a patient respiratory ventilator

A patient respiratory ventilation circuit, comprising:

• a ventilator, operative to provide an inspiratory gas to and receive an expiratory gas from a patient via a patient circuit;
• a system for circuit compliance compensated volume assured pressure control, comprising:
• a volume assurance controller operative to provide an estimated circuit compliance volume compensation factor VOLTID—CTL based on an estimated or measured patient volume, VOLTID—EST or VOLTID—Y, and a preset assured volume VOLASS—SET, and
• a decelerating inspiratory flow corrector operative to modulate an inspiratory flow QINSP—SET based on a preset waveform, a preset inspiratory time TINSP—SET, a preset assured volume VOLASS—SET, and the volume compensation factor VOLTID—CTL output from the volume assurance controller;
• and
• a servo control subsystem operative to control a flow control valve and an exhalation valve of the ventilator according to the preset waveform, the preset inspiratory time TINSP—SET, and the larger amount between the inspiratory flow QINSP—SET modulated by the decelerating inspiratory flow corrector and an inspiratory pressure controller flow QINSP—PRSCTL.

A method for circuit compliance compensated volume assurance pressure control in a patient respiratory ventilation system, comprising:

• a) measuring a patient volume VOLTID—Y through a flow sensor installed at a patient piece of a patient circuit in the ventilation system, or estimating a patient volume VOLTID—EST based on a machine delivered net volume VOLNET and a circuit compliance CT of the patient circuit;
• and
• b) predetermining an initial value INICKT—VOL for a circuit compliance volume compensation factor VOLTID—CTL and updating the volume compensation factor VOLTID—CTL based on a preset assured volume VOLASS—SET and the patient volume VOLTID—Y or VOLTID—EST for each breath;
• and
• c) generating an inspiratory flow QINSP—SET according to a predetermined waveform, a preset inspiratory time TINSP, a preset assured volume VOLASS—SET, and the volume compensation factor VOLTID—CTL.