Blad B, Baldetorp B
Department of Radiation Physics, University Hospital, Lund, Sweden.
Physiol Meas. 1996 Nov;17 Suppl 4A:A105-15. doi: 10.1088/0967-3334/17/4a/015.
Electrical characteristics of living tissues have been investigated for a long time in the search for further methods to complement the traditional investigations of pathology and physiology. Tumour tissue has been shown to exhibit a larger permittivity and conductivity than normal tissues. This might be associated with the fact that tumour cells have a higher water content and sodium concentration than normal cells, as well as different electrochemical properties of their cell membranes. To our knowledge only a few contributions on this subject have been published. This study describes an additional application on measurements of the complex impedance of tumour and normal tissues, in order to compare the impedance features of the two tissue types. The tissue sample is placed in a measuring cell in which the temperature is controlled. The measuring cell is connected to an impedance meter able to measure the complex impedance in terms of real and imaginary part curves for frequencies from 1.5 kHz to 700 kHz. The four-electrode principle is used with the current injected by the outer electrodes and the voltage difference measured between the inner electrodes. The current can be altered up to 1 mA. The instrument can be calibrated with known resistance and capacitance networks connected to the input of the instrument in order to minimize the measurement errors. The calibration routine uses a polynomial adaptation and can be applied interactively. Measurements performed by the instrument show promising results. Preliminary results show that this method can be extended to a new application for detection of tumour tissue by electrical impedance tomography (EIT).
长期以来，人们一直在研究活组织的电学特性，以寻找更多方法来补充传统的病理学和生理学研究。研究表明，肿瘤组织的介电常数和电导率比正常组织大。这可能与肿瘤细胞比正常细胞具有更高的含水量和钠浓度以及其细胞膜不同的电化学性质有关。据我们所知，关于这个主题的文献仅有少数几篇发表。本研究描述了一种关于肿瘤组织和正常组织复阻抗测量的额外应用，以便比较这两种组织类型的阻抗特征。将组织样本置于一个温度可控的测量池中。测量池连接到一台阻抗仪，该阻抗仪能够在1.5千赫至700千赫的频率范围内，以实部和虚部曲线的形式测量复阻抗。采用四电极原理，由外部电极注入电流，并测量内部电极之间的电压差。电流可改变至1毫安。该仪器可通过连接到仪器输入端的已知电阻和电容网络进行校准，以尽量减少测量误差。校准程序采用多项式拟合，可交互式应用。该仪器进行的测量显示出有前景的结果。初步结果表明，这种方法可扩展到通过电阻抗断层成像（EIT）检测肿瘤组织的新应用。
