243例健康人血红细胞悬浮液射频介电特性的研究

STUDY ON DIELECTRIC PROPERTIES OF HUMAN RED BLOOD CELLS IN SUSPENSION FROM 243 HEALTHY PERSONS AT RADIO FREQUENCIES

本文应用同轴传输线反射法建立的细胞悬浮液介电测量系统，测量了２４３例健康人（男１２０，女１２３名）血红细胞悬浮液在１～５００ＭＨｚ频率范围的介电常数和电导率。结果表明不同性别和不同血型之间的红细胞悬浮液的介电参数无显著差异。将１９～８０岁之间的受试者按１０岁年龄间隔分成六个组，探讨年龄差别对介电参数的影响；发现５０岁左右是人红细胞介电参数有显著差异的临界年龄，４９岁后三个高年龄组的介电参数显著地低于４９岁前的三个低年龄组的数值（Ｐ＜０．０５）。本文的结果证明年龄对人血红细胞的介电参数有明确的影响。

The biodielectric measuring system was composed of network analyzer(HP4195A ),self-designed coaxial line sensor and temperature controlling set,Being controlled by an IBM-PC computer,the system was used to measure dielectric parameters of human red blood cells(RBCs) in suspension at frequencies from 1 to 500MHz. Dielectric parameters(permitivity and conductivity) of RBCs in suspension(hematocrit 50%) from 243 healthy persons(120 males, 123 females) were measured at 25℃. The results showed no significant effect of sex,or blood group on dielelctric parameters of RBCs in suspension. Whole volunteers aged from 19 to 80 years were divided respectively into six subgroups in terms of age in order to observe effects of age on dielectric parameters of RBCs in suspension.The statistic results demonstrated that the subgroups could respectively belong to two groups: Group A (subgroup Ⅰ,Ⅱand Ⅲ) and B (subgroup Ⅳ, Ⅴ , and Ⅵ) , The values of permittivity and conductivity in Group A were significantly higher those in Group B, and significant differences existed in dielectric parameters among Group A and B, but nodifference between subgroups in Group A or in B. The results suggested that age had definite effect on dielectric properties of RBCs in suspension, and that there was a critical age(about 50 years) as demarcation of dielectric property change of human RBCs.