Abstract: The changes or variations that occur in physiological parameters of the body when a person is in state of rest, which means he/she is still, lying down, not talking, not under any pressure not even thinking, if possible, is termed as physiological variability (PV). The importance of physiological variability was realised thousands years ago by Indian Medical System, AYURVEDA. It was then referred as “NAADI PARIKSHA”. Today, the Interventional analysis of physiological variability had become crucial for the assessment of Autonomic Nervous System(ANS) activities. ANSis further divided into Sympathetic and Para-Sympathetic Systems which have opposite impact on any of the organ systems of an individual. Increase in the heart rate, the secretions of the glands of alimentary track etc. are some physiological factors controlled by ANS. This paper discusses various research papers and articles, analysing how the factors determining the physiological ari ability can be easily calculated by intervening with the body only non-invasively in order to determine the individual’s health index. Emphasis have also been laid on increasing number of softwares used for analysis of such data; where the developers use various Data Mining Techniques for developing such medically relevant softwares. Heart Rate Variability (HRV), Peripheral Blood Flow Variability (PBFRV) and Morphological Index Variability (MIV) are the main highlights as these are key parameters in PV.

Keywords: Physiological Variability, Automatic Nervous System, Para-Sympathetic Changes, Data Mining.