@article {2139, title = {Point-Process Nonlinear Models with Laguerre and Volterra Expansions: Instantaneous Assessment of Heartbeat Dynamics}, journal = {IEEE Transactions on Signal Processing}, volume = {61}, year = {2013}, pages = {2914{\textendash}2926}, keywords = {Bioengineering}, author = {G. Valenza and L. Citi and E. P. Scilingo and R. Barbieri} }