Performance Evaluation of Multiple Electrodes Based Electrical Impedance Spectroscopic Probe for Screening of Cervical Intraepithelial Neoplasia

Abstract

As regular cervical cancer screening becomes more common, the detection of cervical intraepithelial neoplasia (CIN) is increasing. We proposed a noninvasive and low-cost multi-channel electrical impedance spectroscopy (EIS) and probe with multiple active electrodes for screening CIN. Compared with four-electrode probes for impedance spectroscopy, the multiple active electrodes facilitated more flexible combination of current injection and voltage measurement, which allowed well-designed measurement protocols for focused sensitivity underneath the large size of the probe. Furthermore, the multiple active electrodes reduced the negative effects of the cabling between the system and probe inserted into the cervix. After presenting the basic performance, the EIS probe was tested by three different experimental phantoms using four different materials of electrical properties. The corresponding experimental results were presented to prove the functionality of the EIS probe and characterize the electrical properties at a wide range of frequencies from 0.625 to 100 kHz. It had high sensitivity underneath the surface of the probe and a rapidly decreased outer. Furthermore, we verified the frequency-dependent impedance changes using the giant vesicle phantoms with different amounts of extra- and intra-fluids separated by the insulating membranes. This study facilitates the feasibility into clinical practice for identifying CIN in the future.