A new excitation field for magnetic induction tomography based on the focusing magnetic field

Magnetic induction tomography is a new reconstruction image technology with advantage of non-invasive, nondestructive. The low conductivity for human leads to the weak eddy current field which reflects human conductivity distribution. After analyzing the traditional annular excitation coil without focusing effect, the lid shape spiral coil is proposed which can produce focusing magnetic field. The measurement model with the target object is established for the focusing excitation coil. The primary field and the eddy current field produced within the target object are calculated and analyzed comparatively. The results show that the proposed focusing excitation coil can produce the focusing primary field and focusing eddy current field in the target object, providing an effective method for MIT from the eddy current source.