2019 Volume 71 Issue 2 Pages 141-145
Photoplethysmogram (PPG) for several decades has been commonly used in health monitoring area for the heart rates and oxygen saturation estimations. It has been well researched in terms of these physiological parameters. However, only a limited effort was done towards the investigation of the PPG dynamics, which appears to be highly complex. The methods of nonlinear dynamics were previously used to investigate it. As new types of the PPG have been recently proposed its dynamics need to be carefully studied. This paper gives an overview of the methods of nonlinear time series analysis previously applied to the PPG for its dynamics investigation, and the related results achieved so far.