Application of the Focused Impedance Method (FIM) to Determine the Volume of an Object within a Volume Conductor

M. A. Kadir[1], S. P. Ahmed[2], G. D. Al Quaderi[3], R. Rahman[2], K. Siddique-e Rabbani[1]
[1]Department of Biomedical Physics & Technology, University of Dhaka, Dhaka, Bangladesh
[2]Department of Physics, Jahangirnagar University, Savar, Dhaka, Bangladesh
[3]Department of Physics, University of Dhaka, Dhaka, Bangladesh

Focused Impedance Method (FIM), a new technique of electrical impedance measurement having high sensitivity in the central region, can sense the change in transfer impedance of an object embedded at a shallow depth within a volume conductor of unchanging background conductivity, using electrodes at the surface. This paper presents a new method for measuring the volume of such an embedded object using two electrode separations of a concentric 4-electrode FIM configuration. The formalism developed requires the depth of the object to be known, which is possible using anatomy for objects in the human body, the main target of this research. The new method has been evaluated for a spherical object in a cubic volume conductor using COMSOL Multiphysics®. The error in the evaluated radius of the object was less than 1%.