Photoplethysmogram Parameters Change Depending on Sensor Positioning

Photoplethysmography is a method of recording fluctuations in the volume of blood in the vessels by transmitting light through a tissue area. The purpose of this work is to study the dependence of the amplitude and shape of the oscillations of the optical density of biological tissue at several wavelengths and at various distances from the reflection point of the pulse wave. The article shows the implementation of the optical density sensor. Photoplethysmograms are obtained, the algorithm and results of signal processing are demonstrated.