Effects of Physical Exercise on the Photoplethysmogram Waveform

Photoplethysmography is a non-invasive method which is suitable to estimate vascular compliance. Photoplethysmogram (PPG) waveform has been used to evaluate vascular characteristic changes due to exercise. Quantification of the primary and secondary peak position is of interest as a potential objective, individualized measure of the level of exercise that a subject has achieved with respect to a baseline status, prior to the beginning of the exercise session. The modified bicycle ergonomic protocol was selected for this experiment. Two different signal processing methods were employed in processing the PPG waveform to characterize its changes through a single parameter. Both, the visual inspection of the recorded PPG and the results of the analyses reinforce our opinion about the existence of continuous changes in PPG waveform through an exercise session. The experiment results confirm that PPG can be a potential approach in quantifying cardiovascular characteristics or properties of an individual.