An interactive touchscreen system comprising a conductive panel having a surface portion adapted to receive touch interactions, the conductive panel operatively coupled to a tomograph configured for determining conductivity of the conductive panel and further adapted for incrementally improving a reconstructed tomogram estimation by integrating the output of a tomographic reconstruction algorithm having as input a unreconstructed tomogram delta, the reconstructed tomogram estimation being representative of the panel conductivity properties at locations spatially correlated to a plurality of regions notionally defined over the surface portion and therefrom indicative of the touch interactions, the tomograph further processing and outputting said reconstructed tomogram estimation and an indication thereof.