Direct Magnetic Field Compensation Circuit for Improved Stability of Magnetic Nanoparticle Tomography

Magnetic nanoparticle tomography (MNT) is an imaging technique that uses magnetic nanoparticles (MNPs). When acquiring signals from MNPs, the detection coil is affected by the magnetic field that excites the MNPs. In the conventional method, a digital-to-analog converter and a voltage divider circuit are used to remove the fundamental signal from the excitation magnetic field. In this study, we propose a circuit that uses a fundamental wave extraction circuit to remove the fundamental wave signal and reduce the influence of direct magnetic field fluctuations. The proposed circuit reduces the influence of direct magnetic field fluctuation and successfully detects a signal of the MNP sample at a depth of 50 mm, confirming the feasibility of MNT.