Study on Detecting Phase Deviation in Brain MIT System

Abstract

In the Brain Magnetic Induction Tomography system, the electrical conductivity of biological tissue is in direct proportion to the phase deviation between the excitation signal and the detection signal. The precision of measurement decides the quality of imaging. An experiment with agar-NaCl modals were made to detect phase deviation. We use both digital phase detection method and analog phase detection method to detect phase deviation of the agar-NaCl modals. The results of the experiment showed that both digital and analog phase detection methods can distinguish different kinds of agar-NaCl modals. The higher the conductivity of the modal is the bigger the phase deviation is; also the phase resolution of the digital method is higher than analog’s, which can achieve at 0.01 degree. These may be of great help for further cerebral edema-detecting work.