The Poincar? plot (named after Henri Poincar?) is a popular two-dimensional visualization tool for dynamic systems due to its intuitive display of the dynamic properties of a system from a time series. This book presents the basis of Poincar? plot and focus especially on traditional and new methods for analysing the geometry, temporal and spatial dynamics disclosed by the Poincar? plot to evaluate heart rate variability (HRV). Mathematical descriptors...