Features Extraction in Second Derivative of Finger PPG Signal: A Review

Ancient Indian Ayurveda has used the palpation of the pulse at the wrist under the thumb to analyze physical health. In the nineteenth century, analysis of the contour of the peripheral pulse to assess arterial properties was first described. With the recognition of the importance of arterial stiffness there has been a resurrection of interest in pulse wave analysis. The non-invasive evaluation of arterial indices can be done by analyzing the Finger Pulse wave, obtained using the technique of PhotoPlethysmoGraphy(PPG).Measurements taken directly from thisfinger PPG or from its second derivative can be used to assess these properties. While some work has been done relating the cardiovascular properties with the finger pulse, not much has been done relating Ayurveda to it. This review describes the background of finger pulse contour analysis, its derivatives,its applications, and its future scope. KeywordsFinger PPG pulse wave, Feature extraction,Second Derivate of Finger PhotopleThysmoGraph(SDPTG), Ayurveda, Pitta.