Novel Notch Detection Algorithm for Detection of Dicrotic Notch in PPG Signals

Photoplethysmography (PPG) is a non-invasive optical technique that measures relative blood volume changes in the blood vessels and is widely used for research and physiological studies. Dicrotic notch represent the closure of the aortic semi-lunar valve and subsequent receding blood flow when ventricles relax. Their location is used to calculate systolic time intervals and monitor cardiac function. They play a significant role in early evaluation of various diseases such as sclerosis, occlusion, arterial spasm etc. This paper proposes a novel Notch Detection Algorithm (NDA) for detection of dicrotic notches from PPG signal that are measured by non-invasive photoplethysmography sensors. The proposed algorithm is implemented with the help of self developed Graphical User Interface (GUI) in MATLAB.