Study on magnetic induction tomography system using magnetic focusing coils

Inhalt:
Magnetic Induction Tomography (MIT) is an electrical impedance technology using the eddy current detection principle to detect the conductivity distribution of the tissue. The magnetic induction detection system usually uses circular coils, and the eddy current field generated is mainly concentrated near the surface of the conductor, which has some limitations in reflecting the deep information of objects. In order to improve the central sensitivity, magnetic field permeability, and magnetic field energy convergence of the MIT system, magnetic induction tomography system using a magnetic focusing excitation coil was proposed in this paper. The mechanism of magnetic induction tomography using double 8-shaped magnetic focusing coil was studied, and a five-layer brain ball model simulation was established to study the distribution of magnetic field energy and focusing characteristics of magnetic field energy. The hardware detection systems using double 8-shaped excitation coils and traditional circular excitation coils were constructed. NaCl solution with different conductivity was used as the measured object, and multi-dimensional phase detection experiments were performed. The results proved that compared with the circular excitation coil MIT detection system, higher magnetic field strength at the same position was produced and larger phase difference data for detecting lesions with the same conductivity was obtained in magnetic focusing magnetic induction detection system using double 8-shaped coil, indicating that the double 8-shaped coil detection system had higher magnetic focusing property and could effectively improve the positioning accuracy of the detection area, which was of great significance for the detection of deep brain tissue lesions.