A New Bio-Impedance Forceps Sensor for Measuring Electrical Conductivity of the Biological Tissues

Tissue electrical conductivity measurements are very important for diagnostic purposes. In this paper, an electrical bio-impedance sensor with a biopsy forceps shape was introduced for measuring electrical conductivity of the tissue inside the body. For this purpose, based on the Laplace's equation and the forced boundary conditions in the mouth of the forceps, the relation between electrical conductivity of the tissue and measured electrical potential was analytically obtained. The obtained analytical formula was verified by modeling the electrical bio-impedance forceps and biological tissue in COMSOL software. A prototype of the designed bio-impedance forceps was fabricated and experimentally validated. The validation process was performed by measuring electrical conductivity of the Phosphate -Buffered Saline (PBS) solution with different concentrations. Finally, by measuring electrical impedance spectrum of pulmonary tissues in three different samples at a frequency band of 50 kHz to 5 MHz, it was found that this sensor could be potentially beneficial to discriminate tumoral tissues from healthy ones in biopsy process.