Efficient linear algorithm for magnetic localization and orientation in capsule endoscopy.

To build a new wireless robotic capsule endoscope with external guidance for controllable GI tract examination, a sensing system is required for tracking the capsule's 3D location and 2D orientation. An appropriate sensing approach is to enclose a small permanent magnet in the capsule so as to establish a static magnetic field around. With the magnetic sensors outside the patient's body, some parameters related to this magnetic field can be detected, and the capsule's location and orientation can be calculated using an appropriate algorithm. In this paper, a linear algorithm is proposed to provide faster, more reliable computation, compared to the nonlinear algorithms. The results of simulation and real experiment show that satisfactory localization and orientation accuracy can be achieved using a sensor array with enough number of 3-axis sensors.