ABSTRACT:

Electrical Impedance Tomography (EIT) is a tomographic imaging method that numerically reconstructs the conductivity of an object under test using the boundary voltage-current data collected from the surface.  EIT has wide and important applications, such as in medical imaging, material engineering, civil engineering, biotechnology, and chemical engineering. EIT is well known to be a challenging problem, due to severe ill-posedness of nonlinearity. In this talk, the subspace-based optimization method (SOM) is proposed to solve the EIT problem. Two versions are proposed. The first is the new fast Fourier transform subspace-based optimization method (NFFT-SOM). Instead of implementing optimization within the subspace spanned by smaller singular vectors in subspace-based optimization method (SOM), a space spanned by complete Fourier bases is used in the proposed NFFT-SOM. The second is the low frequency subspace optimized method (LF-SOM), in which singular-vector bases are totally avoided and only discrete Fourier bases are employed. The proposed reconstruction methods are tested by numerical simulations, which show that the proposed algorithms are fast and robust. Finally, the proposed method inspires us to propose an efficient deep learning architecture, based on the convolutional neural network (CNN), to solve EIT in real time.

BIOGRAPHY:

Xudong Chen received the B.S. and M.S. degrees in electrical engineering from Zhejiang University, China, in 1999 and 2001, respectively, and the Ph.D. degree from the Massachusetts Institute of Technology, Cambridge, MA, USA, in 2005. Since 2005, he has been with the National University of Singapore, Singapore, where he is currently an Associate Professor. He has published 150 journal papers, with total citation 4,300+ according to ISI Web of Science (SCI). He has authored the book Computational Methods for Electromagnetic Inverse Scattering (Wiley, 2018). His research interests mainly include electromagnetic inverse scattering, sensing and data fusion, optical/infrared/microwave scanning microscopy, optical encryption, and metamaterials. Dr. Chen was a recipient of the Young Scientist Award by the Union Radio Scientifique Internationale in 2010. He has organized 20+ sessions on the topic of inverse scattering and imaging in various conferences. He has been members of organizing committees of 10+ conferences, serving as General Chair, TPC Chair, Award Committee Chair, etc.  He has been an Associate Editor of the IEEE Transactions on Microwave Theory and Techniques since 2015.