Electrical Tomography Using Ad Hoc Wireless Sensors

R K Y Chin, P Wright, TAYork

Sensing, Imaging and Signal Processing Group, School of Electrical and Electronics Engineering, University of Manchester

Email: t.york@manchester.ac.uk

ABSTRACT

Reconstructed images produced using Electrical Resistance Tomography (ERT) often struggle to reproduce the imaged conductivity distribution to a satisfactory level of accuracy. This can often be traced back to the low spatial resolution of the ERT technique, resulting from the ill­posed nature of the ERT problem. A novel approach, Extended Electrical Tomography (EET), is detailed in this paper, in which ad hoc wireless sensors are integrated into a conventional ERT system with the aim of improving the spatial resolution of the reconstructed images. Sensors located on ad hoc ‘pills’ are used as part of the electrode system, allowing localised voltage difference measurements to be made within the vessel. These localised measurements supplement the conventional set of ERT boundary voltages, increasing the total number of measurements available for reconstruction. Results are presented to compare the performance of EET using a single ad hoc pill to conventional ERT. Analysis indicates that the extended measurements do contain information beyond that available from boundary electrodes. The spatial resolution in the vicinity of the ad hoc ‘pill’ is also improved in comparison to conventional ERT. However, the advantage seen in the spatial resolution analysis is not apparent in reconstructed images.

Keywords Electrical resistance tomography, spatial resolution, 3D measurement strategy,