Design of high uniformity magnetic field coils for magnetoencephalography measurement

The uniformity of the central region within a magnetic shielding room (MSR) is a critical factor affecting the accuracy of magnetoencephalography (MEG) measurement. High uniformity coil design is a key technology for obtaining the required magnetic field environment. This paper introduces a design method of the high uniformity planar coil based on bat algorithm (BA), which significantly enhances the uniformity of the target region. Based on the target field method, a dual-plane coil generating uniform magnetic fields in the x, y, and z directions was designed. Each directional coil consists of a primary coil and a secondary coil. The Bat Optimization Algorithm was used to optimize the distances from the primary and secondary coils to the center point. Finally, the coil structure was simulated and analyzed using electromagnetic simulation software. The results demonstrate a substantial improvement in uniformity by 38% and 40% in the Bx (By) and Bz directions, respectively, compared to coils designed using traditional TFMs. Therefore, the coil system designed using this method can provide a better zero magnetic field environment for the signal acquisition of magnetoencephalography (MEG).