Comparison of three kinds of electrode-skin interfaces for electrical impedance scanning

Low, uniform, and stable electrode-skin impedance is required to achieve good performance of the electrode-skin interface for electrical impedance scanning (EIS) examination. This can be used to measure the real impedance distribution of breast tissue beneath the skin. In this study, the gel interface, the cotton fine grid thin layer (CFGTL) interface, and the hydrogel interface were compared. Experiments were conducted to assess the influence of each interface on the multi-frequency EIS data and their capacity to retain moisture. Results showed that the CFGTL and hydrogel interfaces decreased contact impedance and made the impedance between the electrodes and the breast skin more even and stable. The Cole-Cole model was also used to fit the multi-frequency EIS data. The results demonstrated that the CFGTL and hydrogel interfaces were advantageous for measuring the impedance of the breast tissue under the gel interface. In general, the CFGTL and hydrogel interfaces had good contact with the skin, and both interfaces were proper choices for EIS examination at present. The hydrogel interface was a better choice for our new EIS system.