Study on technique of phase detection in magnetic induction tomography / 医疗卫生装备

ABSTRACT

In the magnetic induction tomography(MIT) system,the electrical conductivity of biological tissue is direct proportion to the phase difference 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 focuses on the means of digital phase detection,including FFT method,the correlation method and the classic method,which are ultimately compared with analogue phase detection method.The experimental results show that FFT method and the correlation method,with low error level and high linearity,can better detect the phase difference with the level of 0.1?.The digital phase difference detection provides a kind of effective method for MIT system.