Active actuation system of wireless capsule endoscope based on magnetic field

Capsule endoscopy, as a new technology involving integrated circuits, MEMS, image processing, radio transmission, and power supply, makes a significant break-through in the GI examination and therapy. However, there are still many problems for the applications of capsule endoscopes, especially for control or actuation of the capsule movement. Therefore, we propose a new technique to address these problems. First, we enclose a permanent magnet in the capsule, to find its localization and orientation by detecting the magnetic field distribution produced by the magnet, and this magnetic field can be measured by magnetic sensors. Second, we place 3 pairs of Helmholtz coils in spatial orthodox way around the human body, to form a rotative magnetic field, to actuate the magnet, so the capsule is propelled. In our system, the permanent magnet plays a role of both the localization, and actuation. This system is in closed-loop mode by using the feedback message from the localization system. Compared with other MEMS solutions, our actuation system has many advantages: no power supply, small space occupation, high-accuracy for positioning, and it will provide the medical doctor a feasible way to control capsule movement wirelessly.