Method and system for controlling a level of ventilatory assist applied to a patient by a mechanical ventilator

A method for controlling a level of ventilatory assist applied to a patient by a mechanical ventilator, comprising:

• determining a first respiratory volume of the patient during at least a part of an under-assisted breath of the patient;
• determining a second respiratory volume of the patient during at least a part of the assisted breath of the patient for a duration matching the at least a part of the under-assisted breath of the patient;
• calculating a volume assistance correction based on the first and second respiratory volumes;
• measuring a pressure at the mechanical ventilator or at an airway of the patient;
• calculating a load of a respiratory system of the patient based on the volume assistance correction and on the pressure at the mechanical ventilator or at the airway of the patient;
• and
• controlling the mechanical ventilator according to the load of the respiratory system of the patient:
• wherein the first and second respiratory volumes are measured for a same value of a neural respiratory drive of the patient;
• and
• using respiratory volume measurements of the patient obtained over a plurality of under-assisted breaths of the patient and over a plurality of assisted breaths of the patient to predict a value of the neural respiratory drive of the patient based on a statistical probability of a similar mean neural drive between the under-assisted and assisted breaths of the patient.