Analysis of the respiratory and cardiac systems coupling in pyramidal exercise using a time-varying model

The analysis of heart period series is a difficult task especially under graded exercise conditions. Among all the information present in these series, we are more interested in the coupling between respiratory and cardiac systems, known as respiratory sinus arrythmia. We show in this work that from the heart period series precise patterns concerning the respiratory frequency can be extracted. Evolutive model is introduced in order to achieve the tracking of the main frequencies and their time-varying power.