Employing dual frequency phase sensitive demodulation technique to improve the accuracy of voltage measurement in magnetic induction tomography and designing a labratoary prototype

Magnetic induction tomography (MIT) is a promising modality for noninvasive imaging due to its contactless technology. Being a non-contact safe imaging technique, MIT has been an appropriate method in compare to other electrical tomography. In this imaging method, a primary magnetic field is applied by excitation coils to induce eddy currents in the material to be studied and a secondary magnetic field is detected from these eddy currents using sensing coils. Image is then reconstructed using measurement data, initial estimstion of electrical conductivity and iterative solution of forward and inverse problems. In the developed 16-coilMIT system, dual frequency phase sensitive demodulation technique is employed to improve the receiver coil voltages measurment. In the dual frequency technique, an auxiliary frequency is used for improving the measurement accuracy and the real and imaginary parts of coil voltages measured in the two different low and high frequency, independently.