@article {1469, title = {Dominant Lyapunov exponent and approximate entropy in heart rate variability during emotional visual elicitation}, journal = {Frontiers in Neuroengineering}, volume = {5}, year = {2012}, keywords = {Bioengineering}, author = {G. Valenza and Allegrini, P. and A Lanata and E. P. Scilingo} }