Investigating the interaction between heart rate variability and sleep EEG using nonlinear algorithms.

Highlights: [•] A new model for monitoring the sleep stages is built based on Hilbert Huang transform. [•] Two main oscillations were defined to depict the feature of sleep EEG based on HHT. [•] Slow- and fast-waves oscillations correspond to fluctuations in the delta and high frequency band. [•] DFA α1 was used to reflect the ANS activity during sleep. [•] The relationship between sleep EEG and HRV was significantly confirmed in this study. [ABSTRACT FROM AUTHOR]