Six-DOF Localization using Magnetic Induction Effect for Automated Locomotion of an Active Capsule Endoscope

The localization of capsule endoscopes using the magnetic induction effect has the potential to be used for in vivo applications. Several magnetic field-based models were proposed to achieve this goal. This paper presents and compares the modeling methods using the Biot-savart law and the point-dipole in the tracking algorithm. We introduce a hardware configuration consisting of three transmitters in a bed and three receiver coils in a capsule body. We quantitatively compare the performance of the two approaches in terms of accuracy and computation time. Biot-savart theory method shows better accuracy; however, its computation cost is much higher than that of the point-dipole model. Finally, we demonstrate the application of the localization system in a closed-loop control using an active capsule endoscope. This work serves as a guide for those who want to develop a localization system using the magnetic induction effect to save the time of analyzing modeling methods.