Nonlinear aspects of the EEG during sleep in children
  Electroencephalograph (EEG) analysis enables the neuronal behavior of a section of the brain to be examined. If the behavior is nonlinear then nonlinear tools can be used to glean information on brain behavior, and aid in the diagnosis of sleep abnormalities such as obstructive sleep apnea syndrome (OSAS). In this paper the sleep EEGs of a set of normal and mild OSAS children are evaluated for nonlinear behaviour. We consider how the behaviour of the brain changes with sleep stage and between normal and OSAS children. 
Matthew J. Berryman, Scott W. Coussens, Yvonne Pamula, Declan Kennedy,   Kurt Lushington, Cosma Shalizi, Andrew Allison, A. ...