@article {martin2013stochastic, title = {Stochastic Modeling of the PPG Signal: A Synthesis-by-Analysis Approach With Applications}, journal = {Biomedical Engineering, IEEE Transactions on}, volume = {60}, number = {9}, year = {2013}, pages = {2432{\textendash}2441}, publisher = {IEEE}, author = {Diego Mart{\'\i}n-Mart{\'\i}nez and Pablo Casaseca-de-la-Higuera and Marcos Martin-Fernandez and Carlos Alberola-Lopez} }