Experimental Study of Dielectric Properties on Human Lung Tissue
This study is aim to investigate the differences of dielectric properties between lung cancer tissue and the normal tissue in vitro and establish the dielectric parameter frequency spectrum of human lung tissue which provide the basic theory and reference data for medical research and clinical diagnosis of lung cancer.Two main categories of tissues were considered as specimens: the central part of the tumor and the normal tissue around the tumor.After operation,specimens was put into test chamber in which the temperature and humidity were controlled at expected values.Then the measurement of specimens' dielectric properties was performed at frequency from 100 Hz to 100 MHz using 4294A impedance analyzer of Agilent Company.Finally the two categories of tissues' characteristic parameters were extracted by using the least square curve fitting method based on Cole-Cole model.The relative permittivity of lung cancer tissue was 3~5 times larger than that of the normal tissue.The conductivity of lung cancer tissue was 1.6~3.3 times larger than that of the normal tissue.Impedance spectroscopy of lung cancer tissue moved apparently to low impedance direction.Among the characteristic parameters(R0,R∞,α,τandfc),the difference of low frequency resistance(R0) between the two categories of tissues was statistically significant(P0.05).The differences of dielectric properties and low frequency resistance between lung cancer tissue and the normal tissue are significant,which provide basic data for human lung tissue's dielectric properties research and EIT measurement.