1. A method for estimating actual effort of breathing of a patient, comprising: receiving respiratory parameters of the patient; calculating respiratory data from the respiratory parameters; inputting the respiratory data into a mathematical model created using clinical data from a population of patients, wherein the clinical data includes pleural pressure or a surrogate of pleural pressure; and generating, using the mathematical model, at least one output variable corresponding to quantified patient respiratory effort, wherein the quantified patient respiratory effort is an estimate of the patient's actual effort of breathing throughout an entire breath, and wherein the at least one output variable is generated by a processor configured to run the mathematical model.