Recognition of Cycles of Repeated Hypoxia on the Basis of Time Periods in Biological Model

Abstract

Recognition possibility of expositions (cycles) on the basis the respiratory response to repetitive hypoxia in experimental model (named as the intermittent hypoxia model) was the aim of the study. Variables of a breathing pattern: respiratory frequency, tidal volume, duration of inspiration and expiration (F, V _T, T_I, T_E, respectively), and phrenic nerve activity (A _phr) were measured in one-minute periods in biological experiments. The data set was analyzed using k-nearest neighbor decision rule (k-NN). It was found that the variables, measured after sequential hypoxic exposures for the recovery phases, allow recognizing cycles with 6.5% of misclassification rate. However, the recognition based on two selected variables F, V _T offered significantly lower error rate of 2%. The obtained results have shown the usefulness of pattern recognition approach to diagnosis of the changes that reflect the respiratory plasticity developing on short-term exposures of the intermittent hypoxia, such as that simulated in the biological model.