If a spectrum of fluctuations in peripheral blood flow is used as an objective index to assess the effect of acupuncture and moxibustion, physiological changes need to be known. We studied the spectra of such fluctuations in healthy subjects under various situations occurring in daily life in association with physiological changes and the symptoms patients complained of. The results are shown as follows.
1) When the autonomic nervous system is well balanced, the fluctuation spectra displayed a pattern where the intensity of the fluctuation frequency components was inversely proportional to the frequency (f), namely a 1/f type.
2) When the sympathetic tone was enhanced or the sympathetic control was not working at the conscious level, the spectrum was close to a pattern where the intensity of fluctuation frequency components was constant and proportional to 1/f⁰ regardless of the frequency.
3) During deep sleep, the spectrum was close to a pattern where a long fluctuation was proportional to 1/f⁰, suggesting that the central conscious level has a great influence on the spectrum.
4) It was suggested that these fluctuations in blood flow take place at the level of arterioles in the corium. Therefore, with a prototype flowmeter produced by the Institute of Applied Electric Science of Hokkaido University, which can measure to a depth of 0.5mm, we were able to measure the spectra of blood flow fluctuations without being limited by the sites of the measurements. However, with a Canon LC-1, which is available on the market, and can only measure to a depth of 0.25mm, we were only able to measure the spectra on the inside of the fingers where the skin is thin.