| The old and pending topic whether varieties of magnetic therapy are efficacious has puzzled the scientific community for many years, but there is still no conclusion. On the other hand, as the technique and equipment based on magnetotherapy has been widely applied in clinical practice, it is urgent to answer the question whether magnetic fields have adverse effects on the human body.As an essential branch of bio-effects of magnetic fields, more and more attention had been attached to the research on the effects of static magnetic fields on microcirculation. According to the domestic and exotic literatures, status quo of this field was reviewed and the potential reason why contradictive and elusive results often appeared in this field of research was analyzed. The modeling of magnetic fields by computer simulation, the experiments of magnetic-related effects on intravital microcirculation and analysis of the variation on regional microcirculation after the exposure of static magnetic field by wavelet transform on laser Doppler flowmetry signal was done to discuss the preliminary modulatory mechanism of the magnetic-related effects on regional microcirculation, in the hope of providing a new approach and route with the further investigation on this field.What had been done in this study could be categorized as follows:1. the model of NdFeB cylindrical rare earth magnet plates, AEMF and PEMF of coils were simulated in order to obtain their three dimensional temporal and spatial distributions by Comsol Multiphysics 3.4 for the first time, which were favorable supplements to the shortage that the magnetic flux density at only several special points could be calculated by classic theory of electromagnetic field. Compared with the data measured practically by the statistical and numerical analysis, the simulative data were certified to be fairly accurate and could be as good complements to the practical measurement and theoretical analysis. In some conditions where much more accuracy was not imperative, the simulative results could even substitute for the theoretical analysis. Thus, it could provide an ideal resolution for the distribution problem of irregular magnetic field which could not be easily measured.2. The acute effects of about 220mT SMF (smaller in size) on microcirculation at aurical for 30 minutes in mice were investigated. It was indicated that the SMF in such size and strength could insignificantly affect the regional resting blood flow on mice auricle. No investigation on such magnetic field and position was reported home and abroad.3. Spectral analysis by continuous wavelet transform was applied to evaluate the acute effects of about 220mT SMF (bigger in size) on microcirculation at nail wall for 30 minutes in young men. it was found that during the SMF exposure, such kind of SMF might induce the enhancement of the intrinsic myogenic, neurogenic and endothelial related activities in regional skin blood flow (P<0.05) while the mean amplitude of skin blood flow flux still maintain at the basal level (P>0.05). Moreover, after removal of SMF, variations of rhythmic flowmotion of SBF in SMF exposure interval vanished gradually, which implicated the limitations of the post-effect of SMF on SBF. Due to, for the first time, combining the electromagnetic shielding technique with noninvasive and real-time monitoring technique on skin blood flow by wavelet analysis and verifying that static magnetic field might potentially affect the modulatory pathways of regional microcirculation, the results might offer new references and methods of evaluation for the further study. |
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