  To study the fundamental physics of complex multiphase flow systems using
advanced measurement techniques, especially the electrical capacitance
tomography (ECT) approach, this article carries out an initial literature
review of the ECT method from a point of view of signal processing and
algorithm design. After introducing the physical laws governing the ECT system,
we will focus on various reconstruction techniques that are capable to recover
the image of the internal characteristics of a specified region based on the
measuring capacitances of multi-electrode sensors surrounding the region. Each
technique has its own advantages and limitations, and many algorithms have been
examined by simulations or experiments. Future researches in 3D reconstruction
and other potential improvements of the system are discussed in the end.
