Effect of Time Varying Magnetic Field on Sensory and Motor Nerve System

为了研究时变磁场在组织中产生的电动势，检测了血液中涡流的强度和分布。方法用E型铁芯制成电磁铁，并建立电磁回路，使交流电从电源向电磁铁循环。研究了电磁回路的特性，测量了在不同磁场作用下血液中的涡流。结果和讨论了磁通密度随通过电磁铁的电流的增加而增加。变化磁场在铜线圈中产生的电动势与流经电磁铁的电流的频率和强度成正比，与铜线圈周围面积成正比。这些结果表明，所观察到的电动势是感应电动势。如果磁场暴露面积固定，则感应电动…血液涡流强度以血浆最强，其次为生理盐水、肝素化动脉血(全血)、红细胞压积。诱导涡流在血浆、生理盐水、肝素化动脉血和红细胞中的分布在腔体周围较低，在腔体中心较高。结果表明，即使在不同的培养基组分下，其分布方式也不变。在1KHz1V探头上测量的介质阻抗：斑块为6.85K omega，肝素化动脉血为7.45KOMEGA，红细胞为16.85KOMEGA。这些结果表明，感应涡流的强度不仅取决于磁通的密度，还取决于介质中的阻抗。随着介质中阻抗的增大，涡流有减小的趋势。较少

The strength and distribution of eddy current in blood were examined for purpose of investigation of electromotive force in tissue induced by time varying magnetic field.Methods Electromagnet was made with E-typed iron core and electro magnetic circuit was established to circulate the alternating current from the source of electricity to electro magnet. The characteristic of electromagnetic circuit was examined and the eddy current in blood under exposure of varying magnetic field was measured.Results and Discussion The density of magnetic flux increased with elevation of electric current through the electro magnet. The electromotive force in copper wire coil induced by varying magnetic field was proportional to frequency and strength of electric current through the electro magnet and area surrounded by copper wire coil. These results showed that this electromotiveforce observed was induced electromotive force. If area under exposure of magnetic field is fixed, induced electromot ivefo … More rce is proportional to density of magnetic flux.Induced eddy current in blood was strongest in plasma and then was in order of normal saline, heparinized arterial blood (whole blood), packed red blood cell. The distribution of induced eddy current in plasma, normal saline, heparinized arterial blood and packed red blood cell was lower in the circumference of the chamber and higher in the center of the chamber. It was showed that the mode of distribution was not changed even if the component of medium was different. The impedance in the medium (measured at 1KHz, 1V) at the probe 6.85 K OMEGA in plaasm, 7.45KOMEGA in heparinized arterial blood, 16.85KOMEGA in packed red blood cell. The more cell component like blood cell increase, the higher the impedance elevate.These findings suggest that the strength of induced eddy current depends not only on the density of the magnetic flux but also on the impedance in the medium. The eddy current had tendency to reduce according to increase of impedance in medium. Less