System for quantifying the discrepancy between a patient receiving assisted breathing and a corresponding assistance device

A method for quantifying the discrepancy between a patient receiving breathing assistance and a corresponding assistance device, comprising the steps of:

• acquiring information of a respiratory rate of a patient over a breathing cycle, using an acquiring device,
• acquiring information of an operating state of the assistance device over a mechanical cycle using an information device,
• filtering an processing this information in order to detect and localize changes in states of the patient over a breathing cycle and of the assistance device over a mechanical cycle, using a filter device,
• calculating a piece of information on desynchronization between the patient and the assistance device from these changes in states, using a calculator, and
• providing a man/machine interface for returning this piece of desynchronization information to an operator,
• wherein the step of acquiring information by the acquiring device comprises a step of acquiring air pressure and flow rate signals in a pneumatic circuit between the patient and the assistance device using an air pressure device, and a step of delivering these acquired air pressure and flow rate signals to an estimator, and a step of continuously estimating the expected theoretical pressure of the air in the pneumatic circuit in the absence of respiratory muscle activity of the patient using the estimator, and a step of comparing the estimated theoretical pressure and a measured pressure, using a comparator device, in order to continuously detect a pressure difference representative of respiratory muscle activity of the patient;
• wherein the calculator calculating the piece of desynchronization information comprises a discrepancy calculator calculating a patient/machine discrepancy score according to the relationship:
• QI(N)=H(N)−[H(B)+H(C)];
• wherein QI(N) is the desynchronization score, H(N) is the Shannon entropy of the (assistance device+patient) system, H(B) is the Shannon entropy of the patient alone, and H(C) is the Shannon entropy of the assistance device alone;
• wherein the operator does not correct the breathing cycle of the assistance device if the desynchronization score QI(N)=0, and corrects the breathing cycle of the assistance device if the desynchronization score QI(N)=1.369 or greater.