Dipole Modeling of Magnetic Marker for Capsule Endoscope Localization

Magnetic field has great potential to be applied to the localization of wireless capsule endoscope. For simplicity of the calculation without increasing the position error, this paper investigates the feasibility of modeling the magnetic marker as a dipole. The field distributions of two small cylindrical permanent magnets, which are suitable for localizing the capsule endoscope, are calculated using FEM. Comparison is made with the magnetic fields of the equivalent dipoles to show the conditions of modeling. The results also show that the short magnet is more suitable for the localization than the long one.