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BASIC RESERCH FOR APPLICATION OF VARYING MAGNETIC STIMULATION

变磁刺激应用基础研究

基本信息

批准号：
03454458
负责人：
UMINO Masahiro
金额：
$ 4.03万
依托单位：
TOKYO MEDICAL AND DENTAL UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1993
项目状态：
已结题

项目摘要

1) Dielectric constants of blood samples have been first measured in the frequency region, 20Hz-30MHz, by the two electrode method. Samples were human whole blood, plasma, lysed er-ythrocytes, packed red cells, the interior solution of erythrocytes, and the physiological saline. Dielectric constants of samples were derived from the capacitances measured.From this result, it was found that the contribution of the electrode polarization to me-asured values of dielectric constants was considerable in the low frequency region, that is the alpha-dispersion region. Then, in order to eliminate the effect of the electrode polarization, dielectric constants were secondaly measured by the four electrode method, result-ing in that the effect of the electrode polarization is greatly reduced in the low frequency region ((〕SY.ltoreq.〔) 10KHz). Comparing measured values of dielectric constants of six samples, it is concluded that (1) the so - called alpha-dispersion in low frequencies is mostly due to the electrode polarization and is not real, and (2) the so - called beta-dispersion is due to the structural dispersion as pointed out before.2) Relation between electrode polarization and intensity of electric field was investigated in iontophoresis. Samples were 1 % of xylocaine and physiological saline. Potential difference in medium was decreased by delivering direct current. Marked decrease of potential difference was observed under constant voltage. Decrease of potential difference was due to electrode polarization. It is possible to improve iontophoresis by blocking electrode polarization.

1)首次用双电极法测量了血液样品在20Hz-30MHz频率范围内的介电常数。样品为人全血、血浆、溶er红细胞、填充红细胞、红细胞内液、生理盐水。样品的介电常数由测得的电容导出。从这个结果可以看出，在低频区，即色散区，电极极化对介电常数的确定值的贡献是相当大的。然后，为了消除电极极化的影响，采用四电极法对介电常数进行二次测量，使得电极极化的影响在低频区域大大降低([]SY.ltoreq。[) 10KHz)。对比6个样品的介电常数测量值，得出结论：(1)低频的α色散主要是由电极极化引起的，不真实；(2)如前所述，β色散是由结构色散引起的。2)研究了离子电泳中电极极化与电场强度的关系。样品为1%的木卡因和生理盐水。通过输送直流电，降低了介质的电位差。恒压下，电位差明显减小。电位差的减小是由于电极极化所致。通过阻断电极极化可以改善离子透入。