Mechanism Research On Biological Effects Of Low Intensity Pulsed Magnetic Fields

In these years, the study of the biological effects of magneticfields has been listed as the important task in the field of biomedicalengineering. With the continuous support from NSFC (1. Mechanism studyof low-intensity pulsed electromagnetic fields on cardiovascular disease,50077023 (in 2000), 2. Mechanism study of low-intensity pulsedelectromagnetic fields on osteoporosis, 50377044 (in 2003);The authoris principle investigator of these two studies), the biological effectsof magnetic fields is studied systematically. In this dissertation,firstly, the advances of applications and background in biologicaleffects of electromagnetic fields are systematically summarized. Tostudy the biologic effects of low intensity pulsed magnetic fields oncardiovascular diseases and osteoporosis, the properties of physiology,biochemistry, immunity and biomechanic are examined, the animal modelsare established, osteoblasts are cultured in vitro. The mechanism ofbiological effects is discussed in detail. It is favorable to providenew methods and theoretical basis for preventing and curingcardiovascular diseases and osteoporosis. The work can be summarized asfollows:1. Based on the theories, such as resonance effect, coherentelectric oscillation, penetration of particle and convolution resonance,et al. the mechanism of athermal biological effects of magnetic fieldsis analyzed. The interactional effects between magnetic fields andorganism are studied: â‘ Organism's response characteristic to certainmagnetic fields is non-linear, and shows obvious frequency and powerpeculiarities, which is called "windows effect";â‘¡So far as theextreme low frequency(<100 Hz), low intensity(<100 Gs) is concerned,athermal effects have distinct advantages over thermal effects. Lowintensity pulsed magnetic fields can cause easily athermal cumulateeffects.2. The experimental animal models of hyperlipidemia, osteoprosisand atherosclerosis are successfully established. The properties ofphysiology, biochemistry, immunity and biomechanic, such as hemorheology,blood lipid, cardiac function, histomorphometry, bone mineral densityare examined. Combined with cell culture, the effects of low intensitypulsed electromagnetic fields on cardiovascular diseases andosteoporosis are systematically studied, the mechanism of biologicaleffects is discussed. It is favorable to provide new methods andtheoretical basis for preventing and curing cardiovascular diseases andosteoporosis.3. By analyzing the mechanism of vessel stressed vibration, basedon the theory of electromagnetic fields, the view is propounded, whichindicates that the pulsed magnetic fields can cause resonance of vesselunder certain frequency and low radiation dose of pulsed magnetic fieldscan induce much more effects. By using FFT analysis, the relation betweenbiological effects and radiation dose is discussed.4. A point of view of circadian affecting biological effects ofpulsed magnetic is firstly proposed. Organism, from mammal to bacteria,has a biological clock. Circadian rhythm determines the consistentpattern of behavior of physiological and biochemical functions inorganisms, such as periodicity of sleep-wake, thermoregulation, levelof hormone released and so on. This can be forward to improve experimentaldesign and repetitiveness.5. A instrument of Low intensity pulsed magnetic fields(Chinesepatent, ZL02224739.4)is developed. To meet the requirements of animalexperiments, by theoretical calculation, a new method of gaining morehomogeneous magnetic fields is propounded. The output uniform region ofmagnetic fields is larger than that of Helmholtz coil, which can improvethe general level of experiments.