A new localization system for tracking capsule endoscope robot based on digital 3-axis magnetic sensors array

Abstract

This paper proposes a new magnetic localization system for capsule endoscope robot which works wirelessly in the human body by using a 4 × 4 sensors array, composed by the latest digital magnetic sensors, QMC5883L. In order to locate a capsule effectively and non-invasively, we apply the static magnetic field method by enclosing a small cylindrical permanent magnet in the capsule. The position and orientation of the permanent magnet are related to its magnetic signals like field intensity and direction which can be measured by the sensors array outside the human body. The relations between the magnet and its signals can also be formulated by equations, as a cylindrical permanent magnet can be considered as a magnetic dipole model. In Matlab, we can approach the equations for parameters containing location information by using non-linear least squares algorithm with Levenberg-Marquardt optimization method. The experimental results show that accuracy is well controlled and the digital sensors are applicable for the tracking systems.