Modelling, Calibration and Fabrication of Electrical Capacitance Tomography Sensor for Bone Imaging

Abstract

Electrical capacitance tomography is a technique to measure internal permittivity distribution based on external capacitance measurements which in turn generate a cross-sectional image representing the permittivity distribution thereby the material distribution. It possesses the advantages of non-radioactive, non-intrusive, non-invasive, high imaging speed and low cost over the conventional medical imaging techniques. Inter-electrode measurements are done by placing electrodes around the non-conductive dielectric medium cylinder inside which, the medium to be imaged is placed. This paper emphasizes on modelling and fabricating an electrical capacitance tomography sensor using ANSYS APDL for bone for which the sensor is calibrated using air and water. ECT sensor is modelled and fabricated by mounting 12 identical rectangular copper electrodes were placed symmetrically outside the Poly-vinyl chloride (PVC) cylindrical tube. The output from sensors can be converted to digital voltage values used for image reconstruction in MATLAB.