Research On Control Of Wireless Micro-robot For Intestines And Stomach Inspection Driven By External Magnetic Field

The capsule endoscope travels through the GI tract, shooting and sending out images o The traditional fiber endoscope was driven by external manipulation force, so proficient operation technique was required to prevent pains and injury of organs. The long cables for energy supply and signal transmission in microrobotic endoscopic systems might also cause surface injury and reduced the mobility of the robots. Wireless capsule endoscope was propelled by gastrointestinal peristalsis, thus its locomotion was very slow and uncontrollable. To overcome above disadvantages of intestinal endoscopic systems, a new type of wireless microrobotic endoscopic system for intestinal inspection was developed.The capsule endoscope travels through the GI tract, shooting and sending out images of the GI tract, and evacuates finally. To ensure the security of GI inspection, no approving method has been developed by far to drive the capsule endoscope but utilizing the natural peristalsis of GI tract.The uncontrollability of the capsule endoscope brings on some limitations in its functional extension in inspection, medication and surgery, such as temperature and pH measuring, medicament spraying, sampling, on-line sample analyzing, laser incising and RF cauterizing. Perfect micro-robot system for diagnosis and treatment will call for good driving control such as attitude adjusting, locomotion and locating.This paper presents our research in actuating in-vivo micro-robot based on the capsule endoscope platform by the external power. While seeking secure driving method we take several factors into account, such as driving environment, power transmitting and consuming, motion requirement and controllability, and locating technique. We mainly deal with driving the capsule with spatial gradient magnetic field, so we employ combined electro-magnetic coils, including gradient coils and homogenous coils, which have rotational DOF around a translatable patient bed, to compose a controllable uniform gradient which act on the permanent-magnet embedded robot, thereby get an appropriate spatial force and torque to fulfill the anticipant locomotion such as move, stop, pitch and yaw.