a method of creating a non - invasive predictor of both physiologic and imposed patient effort from airway pressure and flow sensors attached to the patient using an adaptive mathematical model . the patient effort is commonly measured via work of breathing , power of breathing , or pressure - time product of esophageal pressure and is important for properly adjusting ventilatory support for spontaneously breathing patients . the method of calculating this non - invasive predictor is based on linear or nonlinear calculations using multiple parameters derived from the above - mentioned sensors .