Abstract:

In order to solve the phase difference detection in brain magnetic imaging (MIT) systems,we improve and achieve a phase MIT software platform.Software is LabVIEW2009,and phase detection uses FFT phase detection algorithm;hardware is the NI PXI 5122 data acquisition card of 100 MS·s^-1 real-time sampling,and consider the use of electromagnetic security module for the weak gain amplification of small signal amplification.A sampling of high precision,adjustable amplification gain,FFT-based algorithm phase MIT software platform is built.In the simulation experiments of Cerebral hemorrhage phase detection,phase difference increases with the amount of bleeding;and with constant excitation signal power,the phase difference increases with excitation frequency.Phase accuracy improves from the original 0.01 degrees to 0.001 degrees,which indicates that the MIT system could better reflect changes in tissue conductivity.

Key words: brain magnetic induction tomography;LabVIEW2009;FFT;phase detection