A magnetic stereo-actuation mechanism for active capsule endoscope

The commercial available capsule endoscope lacks a self-actuation mechanism and the passive locomotion mode results in a low diagnosis efficiency or even missing of the diseases. An actuation mechanism is necessary for an active capsule endoscope to carry out thorough examinations and further operations efficiently. In this paper, after measuring the force needed for driving the capsules in the small intestine, we introduced a wireless stereo-actuation mechanism taking advantage of magnetic force and torque. A small permanent magnet was enclosed into the capsule as a seed to be actuated by multiple current coils placed around the abdomen area. An optimization algorithm was designed for selection of the most economical coil currents. Experiments and results show the current level for six orthogonal coils of reasonable size to actuate the capsule in the pre-determined position and direction.