Magnetic materials for endoscopic capsule steering and active motion inside the human body

Abstract

The interest in the development of endoscopic capsules (EC) has grown at a tremendous pace, since they promise to perform diagnosis in a less invasive way in those areas accessible by traditional exams to the small bowel and colon, and to access new areas of the GI (gastrointestinal) tract. The benefits of EC to improve the quality of medical exams are well known. Despite their advantages, the lack of mechanisms to control its navigation through the intestine is a drawback. This paper presents the materials used in the construction of a magnetic locomotion system for endoscopic capsules. The locomotion system is based on an external permanent magnet (EPM) controlled by the operator and an internal permanent magnet (IPM) mounted inside the EC can improve the motion behavior of the capsule inside the patient. The EPM presented a cylindrical shape, a volume of 4,5x105 mm3, a weight of 4,1 Kg and a very high magnetization (e.g., N48) with maximum measured magnetic field intensity of 1.5 T. The shape and size of a IPM made of neodymium rare earth magnetic is a topic of further optimization in order to be mounted inside the EC for guiding the capsule inside the patients.