Characterization of inspiratory flow limitation during sleep with an exponential model

Assessing incidence and severity of inspiratory flow limitation (IFL) is of importance for patients suffering of sleep disordered breathing (SDB) in order to diagnose a spectrum of different pathologies. In this study a new exponential equation is proposed to characterize the pressure/flow relationship of IFL and non-IFL breaths. Classical and alternative criteria are applied on the model´s predictions in order to assess IFL, and its outcome is compared to the outcome of other models. The newly proposed exponential model seems to be promising, as it outperforms other models by achieving a global average sensitivity of 93% and specificity of 91%, and the lowest mean square error when estimating resistance at peak pressure. Additional statistical tests were performed on the exponential model´s coefficients in order to determine if a coefficient based classification is possible.