Heartbeat fluctuations

In a normal quiet subject, the heartbeat looks very regular. When it is measured precisely, however, a slight fluctuation of the period will be found from beat to beat. The fluctuation of the heartbeat period was found to have 1// spectrum for frequency below 0.01 Hz, above which the spectrum was approximately in proportion to Xjp as is shown in Fig.2. This result was my surprize because 1// fluctuations are ubiquitously observed in electric conductivity in any type of electric conductors, and the physical mechanism is not clear as yet regardless of its history as long as more than 60 years. Moreover, it was also observed that heartbeat period fluctuations of an embryo became small, in other words, more regular when its mother got ill, and activity of the heartbeat fluctuation recovered its activity when the mother became healthy. The heartbeat fluctuation is a measure of the vitality of life. 

After finding that the heartbeat period is subject to 1// fluctuations, the present author drew parallel lines on a sheet of paper such that their space intervals are equal to heartbeat time intervals, and realized that it looked very much like a wood-grain pattern. Therefore, the spectrum of wood-grain pattern was investigated in terms of spatial frequency. The result is shown in Figs.Ta and b corresponding to... 

Yambe, T., Nitta, S.-L, Sonobe, T., Naganuma, S., Kakinuma, Y, Kobayashi, S.-l., Nanka, S. et al. 1993. Origin of the rhythmical fluctuations in the animal without a natural heartbeat. Artif. Organs 17 1017-1021. 

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