Planar Electrode Configurations of Electrode Plates for the Localization of Cervical Abnormality based on Electrical Impedance Tomography (EIT) A Simulation Study

Abstract

Screening for the early stages of cancer is one of the challenges nowadays. Current screening techniques such as Pap smear and liquid base cytology require many laboratory processes and time. Screening for cervical intraepithelial neoplasia (CIN), in particular at the very beginning grades, is difficult. To screen for CIN, the electrical impedance of tissues is recently used and it seems very promising to identify the presence of precancerous cells without the need for laboratory processes. However, since the location of precancerous cells of a specimen is usually unknown as well as the size, measuring bioimpedance directly on specimen tissue is then difficult and requires repetitive measurement. In this paper, two planar electrode layouts i.e. Star and Circular layout are proposed here. The number of electrodes of both layouts is 16 which is suitable for electrode plates. With this method, all measurements can be collected at the same time. We utilized the measurement data by reconstructing the image of conductivity distribution which can show the locations of abnormal cells, based on Electrical Impedance Tomography (EIT). The simulation result shows that both layouts can locate simulated Grade3-CIN objects in a 25 mm-diameter cervical tissue when it is situated in the sensitive measurement region. However, the amplitudes of reconstructed CIN are all much smaller than the true amplitude approximately by 10 times. The overall localization error of the star layout where the array was denser than the other, was smaller by 2 times i.e. 0.6351 mm for the star layout and 1.2859 mm for the circular layout because the sensitivity of the star layout is higher due to the smaller area of the electrode array. However, the localization error of the star layout was worse than the other by 2 times when CIN was located at the orifice i.e. 1.4597 mm for the star layout and 0.7488mm for the circular one. Nevertheless, for the star layout, the artifact at the orifice region was larger and CIN located at the tissue edge cannot be reconstructed. Therefore, we recommend to use the circular layout for locating cervical cancer. © 2021 ACM.