Design Method of a Novel Helmet-Shaped Wearable Self-Shielding Coil

To satisfy the development of portable and miniaturized extremely weak magnetic measuring devices, a novel helmet-shaped wearable self-shielding coil (HWSC) design method is proposed in this article. An analytical calculation model of HWSC is established by the boundary element method (BEM) which achieves the optimum design of self-shielding coils with a high homogeneous magnetic field (MF). Weighting coefficients are introduced to precisely control the selection of target field points. The calculated maximum MF deviation inside the HWSC and maximum MF attenuation deviation outside are 2.28% and 16.08%, respectively, which reduces the external MF attenuation by 69.15% compared with the coil without considering coupling. The experimental results show that the maximum internal deviation and external attenuation deviation of HWSC are 2.86% and 17.84%, respectively. This approach provides new ideas for the optimal design of internal coils in the development of magnetically shielded devices toward miniaturization and portability.