The design of a FPGA-based digital magnetic induction tomography (MIT) system for metallic object imaging

This paper presents the software and hardware design aspects of the first digital MIT system. Excitation signal generation, receiving signal demodulation and channel multiplexing control are all implemented inside a Xilinx FPGA (Spartan III). The image reconstruction software is written in VC++ and real time images up to 200 frames /second can be achieved for 50 K Hz excitation. Fitted with an 8 coil MIT sensor, the digital system delivers a much higher signal to noise ratio (SNR) and image stability compared to the analog system previously designed. Metallic samples of different shapes and arrangements were imaged, which confirms the performance of the system.