Estimation of Arterial Stiffness by using PPG Signal: A Review

Arterial stiffness leads to cardiac disorders, the degree of arterial stiffness can be obtained by calculating the augmentation index, arterial stiffness index and reflection index of a pulse wave. Three different algorithms can be used to determine the above indices i.e. finding local and global maxima and minima by slope gradient method, zero-crossing point identification and intersecting tangents. Thus by calculating the augmentation index, arterial stiffness index and reflection index the degree of arterial stiffness can be calculated by which cardiac risk of a patient can be diagnosed. All three indices can determined by implementing an algorithm in MATLAB. In this paper we have discussed various methods to analyse and estimate the arterial stiffness parameters and software tools available for analysis. Keywords— Cardiac risk, PPG, Augmentation index