Photoplethysmography: Design, Development, Analysis and Applications in Clinical and Physiological Measurement – A Review

Photoplethysmography is a non-invasive, electro-optical technique for detecting the cardiovascular pulse wave generated by elastic nature of the peripheral vascular arteries by the contraction of heart. Photoplethysmogram (PPG), a pulse wave generated varies in accordance to blood volume changes in the microvascular bed of a tissue. This review paper emphasizes on the earlier works on the design and development of data acquisition system, analysis methods and applications of PPG. Based on the research gaps from review, in the present work a ZigBee based wireless PPG system for real time monitoring and assessment of cardiovascular and respiratory systems has been designed and developed. The PPG signals recorded from 25 normal subjects and 20 cardiac patients from the index finger. Pulse rate (PR), average pulse rate (APR) pulse rate variability (PRV) and spectral analysis is carried out on acquired PPG signals using Matlab. The study and results shows PPG can be an alternative to the traditional methods.