Study on Technique of Phase Detection in Magnetic Induction Tomography

In the magnetic induction tomography (MIT) system, the electrical conductivity of biological tissue is in direct proportion to the phase deviation between the excitation signal and the detection signal. To obtain the image of the contribution of tissue´s electrical conductivity, the system must have the function of phase detection with high accuracy. The paper focused on the means of digital phase detection, including the FFT method and the Correlation method, which were ultimately compared with analog phase detection method. The experimental results showed that both the FFT method and the Correlation method, with low error level and high linearity, can better detect the phase deviation with the level of 0.1 degree. The digital phase detection provided a kind of more effective method for MIT system.