Excitation Strategy Analysis of Magnetic Induction Tomography for Intracranial Hemorrhage Detection

Magnetic induction tomography (MIT) is a promising technique for intracranial hemorrhage detection due to its non-radioactive, low cost, contactless features. Under different excitation strategies, an MIT sensor array can produce different magnetic field and sensitivity distribution. A multi-coil excitation strategy is proposed and the effect of different excitation strategies on hemorrhage imaging is investigated. The relationship between the excitation frequency, conductivity and response signal under multi-coil excitation was analyzed based on the equivalent circuit. The calculation formula of sensitivity matrix under multi-coil excitation was derived. In the simulation, a planar local sensor array and a 3D anatomical head model were established. Two excitation strategies: single excitation strategy and adjacent reverse excitation strategy were analyzed and compared. The results indicate that the sensitivity distribution under the adjacent reverse excitation is more concentrated compared with the single excitation strategy. It can effectively suppress the influence of the background signals from other tissues and has the ability to detect the hemorrhage with smaller volume. The analysis and optimization of the excitation strategy may provide a solution for further improving the spatial resolution in intracranial hemorrhage detection and promotes the development of MIT in biomedical imaging.