電阻抗是一種常用來測定物質特性的方法，特別是應用在生物醫學領域上。生物電阻抗頻譜可以測量出組織的電阻性與電容性。在本研究中，我們使用一個簡單可攜帶基於商用積體電路的生物電阻抗頻譜系統來測量大白鼠接受放射線照射後的腸組織，然後將生物電阻抗頻譜測量結果代入電容與電阻組成之等效電路模型，以求得組織電氣特性，再將組織電氣特性與組織型態變化做比較。實驗結果顯示生物組織電氣特性依診斷測試分析對組織學上的變化有高度的反應且優良的偵測表現 (Receiver operating characteristic analysis, Area under curve: 0.95-1.00, p<0.01)。除此之外，在組織切片影像上低染色面積也與組織電氣特性有關。細胞外電阻與組織切片影像上低染色面積其相關性最高(Spearman’s rank correlation: -0.757, p<0.01)。此研究確立與支持電氣切片的結果可以反應傳統生物組織學之發現且與之相關，而這種方式應用在組織之病理診斷上有很大的潛力。利用組織之電氣特性來研究與區別組織之狀態，此概念可以稱作電氣切片。

Electrical impedance is one of the most frequently used parameters for characterizing material properties, especially in biomedical applications. The resistive and capacitive characteristics of tissue may be revealed by electrical impedance spectroscopy (EIS). In this study, rat intestinal tissues after irradiation were assessed by a portable and simple EIS system based on commercially available integrated circuits. The EIS results were fitted to a resistor-capacitor circuit model to determine the electrical properties of the tissue. The variations in the electrical characteristics of the tissue were compared to morphological and histological findings. The electrical properties, based on receiver operation characteristic (ROC) analysis, strongly reflected the histological changes with excellent diagnosis performance (Area under curve: 0.95-1.00, p<0.01). In addition, the ratio of the optical low staining area of the sampled histological image varied with the tissue’s electrical parameters. The parameter most strongly correlated with the ratio of optical low staining area was extracellular resistance (Spearman’s rank correlation: -0.757, p<0.01). The results of this study confirm that electrical biopsy reflects conventionally described histological changes. This approach may significantly augment tissue pathological diagnoses. The electrical parameters of the tissues could be used to assess tissue status during investigation, and this concept can be referred to as “electrical biopsy.”

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