Can Very High Frequency Instantaneous Pulse Rate Variability Serve as an Obvious Indicator of Peripheral Circulation?

HRV (heart rate variability) is a general noninvasive method for indicating the activities of ANS (autonomic nervous system). The surrogate of HRV is PRV (pulse rate variability), where the variability of resting PPG (photo plethysmo graphy) indicates the activities of ANS and peripheral circulation. However, the quick responses of thermoregulation and limb movement are restrictedly performed since of the beat-to-beat timescale property of PRV. Recently, iPRV (instantaneous pulse rate variability) has been developed to break the limitation. The iPRV adopts empirical mode decomposition for noise reduction and estimates the instantaneous period for higher time resolution. Thus, an ultra-frequency band called VHF (very high frequency) was held. The aim of this study is to concentrate the iPRV presentation on fever adolescent who is possibly under immature body regulation. Thirty participates, whose age were 7 to 18 years old, were recruited in pediatric clinic. The resting PPG signals were acquired for 10 minutes in a supine position. The analysis results show the conventional ranges of iPRV also observe the activities of ANS. As well, the modified indices including VHF are significant difference (p-value < 0.05) between fever and feverless symptoms. Based on the statistical evidence, this study provides the potential of the indicator of thermoregulation on peripheral circulation.