Optimization design of sensors for maximum primary field cancellation in biomedical magnetic induction tomography

Magnetic induction tomography (MIT) in vivo is to reconstruct conductivity of biomedical tissue by coil sensors which are imposed alternating current as well as detecting signals induced by tissue around the coils. In addition to the secondary signals due to tissue parameters, the resulting signals also include the primary field signals contributed by excitation coils which are approximately 5 times orders of the secondary signals. This not only reduces measurement precision, but also affects reconstruction image resolution. Optimization coil sensors can cancel primary field greatly at source. The paper presents coil sensors arrangement suitable for Biomedical magnetic induction tomography. Relative position between the excitation and detection coils was adjusted to reduce the primary signals in resulting signals. Simulation was performed from single-channel to multiple-channels system. The measurement results of all the systems suggest that the signal due to the primary field can be reduced individually at the operating frequency of 10Mz.