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为了探索脑白质和脑灰质在β、δ和γ色散过度区间内的介电特性在临床医学和微波成像技术上的应用,本文应用Cole-Cole公式计算脑白质和脑灰质的相对介电常数及增量,并以相对介电常数增量的突变为依据,判断3种色散发生的频域区间;而后利用Cole-Cole圆分析过渡区内哪种色散占核心地位,以及相应的极化机制,从中寻找有价值的数据和规律。结果表明:脑白质在β与δ色散之间、β与γ色散之间、δ与γ色散之间有3种色散过渡区间,而脑灰质仅在β与δ色散之间和δ与γ色散之间有2种过渡区间;脑白质的β与δ色散过渡区间频率范围宽于脑灰质的,且在这两种物质中β与δ色散过渡区间内均以β色散占核心地位,其相应的极化机制为界面极化;脑白质的δ与γ色散过渡区间频率范围也宽于脑灰质过渡区间的频率范围,且在这两种物质中δ与γ色散过渡区间内均以δ色散占核心地位,其相应的极化方式为转向极化。通过以上研究,本文结果可为脑组织疾病的诊断和微波成像技术提供理论依据和数据参考。
In order to explore the application of the dielectric properties of white matter and gray matter in the β, δ and γ dispersion over clinical and microwave imaging, Cole-Cole formula was used to calculate the relative permittivity of white matter and gray matter and The Cole-Cole circle is used to analyze which kind of dispersion takes the core position and the corresponding polarization mechanism, Looking for valuable data and rules. The results show that there are three kinds of dispersion transitions between δ and γ dispersion in the white matter of β and δ, β and γ dispersion, while the gray matter of brain is only in the range of β and δ dispersion and δ and γ dispersion There are two transitional intervals; the white matter β and δ dispersion transition frequency range broader than the gray matter, and in these two substances β and δ dispersion transition within the range of β dispersion accounted for the core, the corresponding pole The mechanism of polarization is interfacial polarization; the frequency range of δ and γ dispersion transition of white matter is also wider than the frequency range of gray matter transition, and δ dispersion takes the core position in both δ and γ dispersion transition , The corresponding polarization is steering polarization. Through the above research, the results of this paper can provide theoretical basis and data reference for the diagnosis of brain tissue diseases and microwave imaging technology.