A Novel Current-Interference Scanning Method for Detection of Abnormal Tissues

This paper presents a current-interference scanning (CIS) method for detecting abnormal tissues (such as breast and lung tumors) characterized by a significantly higher electrical conductivity than healthy tissues. The CIS method overcomes several limitations encountered in existing screening techniques based on electrical impedance tomography (EIT), which usually suffer from poor spatial resolution due to the limited number of electrodes that can be attached on human body. In addition, the reconstructions of the impedance image in EIT are often poorly conditioned due to its uneven sensitivity to different areas and ill posed for limited information. In this paper, the theoretical basis of a CIS method is analytically derived, which uses two high-frequency sinusoidal currents to create a low-frequency current-interference area moving in two orthogonal directions. The effectiveness of the CIS method and its feasibility for detecting relatively large different electrical conductivities in human tissues are illustrated numerically and experimentally.