Caffeine dose dependent blood perfusion: Effects on rhythmic activities using frequency spectrum

The dependency of blood perfusion on caffeine doses and the effects on different rhythmic activities were investigated by spectral components of skin blood perfusion signal. The skin blood perfusion on human forearm middle finger tip was recorded by laser Doppler flowmetry technique at both before and immediately after the consumption of caffeine dose. Different caffeine doses contained different amount of caffeine but approximately same amount of sugar. Recorded and processed data was investigated using spectral component within the frequency range 0.009-1.6 Hz. It was found that the consumption of caffeine free dose increased the heart activity about 85.66% where other activities showed a tiny change. Consumption of low value caffeine dose resulted notable decrement in metabolic, myogenic, and heart activities. Consumption of moderate value caffeine dose resulted significant increment in sympathetic, respiratory, and heart activities. High value caffeine dose consumption resulted remarkable increment in sympathetic (230.26%) and myogenic (263.01%) activities. The results indicated significant decrement and increment for low and high value caffeine dose consumption respectively.