Open-loop control experiment of wireless capsule endoscope based on magnetic field

This paper presents an experiment of using external magnetic field to implement the actuation of wireless capsule endoscope with open-loop control strategy. We use two pairs of rectangle coils to generate rotary magnetic field. The capsule with a permanent magnet rotates along with the magnetic field. With the help of the whirl on its surface, the capsule can move in a certain direction. From the experiment, we find out the critical frequency of rotation when the capsule can rotate smoothly. Besides, we improve the existed mathematical model of the coil's magnetic field. The thickness of the coils is taken into account. Finally, MATLAB simulation experiment is carried out to analyse the relation of the coils' sizes and the character of magnetic field distribution. The result shows the intensity and uniformity of the magnetic field cannot be optimal simultaneously, so different weight should be set to determine coils' sizes in practice.