Photoplethysmogram (PPG) signal analysis and wavelet de-noising

The use of optical sensors is nowadays very common in the area of non-invasive diagnosis. This is mainly because of their salient features like, simple construction, low cost, easy to use, relatively inexpensive nature etc. Photoplethysmography (PPG) sensor is one among the wide variety of optical sensors available, and is used to measure the blood volumetric changes occurring in the various parts of the body. PPG signal contains rich source of information related to cardio-pulmonary system. But the major problem associated with the signal is the motion artifacts, causing corruption in the original PPG signal. The aim of this study is to know in deep about the different parameters of PPG signal. Peak and transition points of the pulse signal are determined as a part of pulse wave analysis. Wavelet transform is now commonly used in a wide variety of signal processing applications. In this work wavelet de-noising is used for removing AWGN from the PPG signal. Various mother wavelets are studied and the performance of them are evaluated based on the cross correlation with the original signal.