Study of magnetic levitation technique for use in a wireless capsule endoscope

In recent years, stomach and colon cancers have accounted for the most deaths among malignancy patients in Taiwan. From the view of health, it is a wise choice that people choose traditional gastrointestinal (GI) endoscopic examinations for early detection of malignancies, even though such examinations often involve uncomfortable and painful procedures, which discourage suspected patients. Nowadays, the new Wireless Capsule Endoscope (WCE) is an advanced technology to use semiconductor processes and telecommunication techniques. The WCE is a miniature and wireless device, yet it cannot observe the stomach and colon under command. Thus, we propose a WCE carrier to be placed into the mouth, and a magnetic levitation (MAGLEV) system that would levitate the WCE by electromagnetic force from outside the body. Such a system could very likely diagnose the digestive system and minimize the pain and discomfort incurred. In this paper, related issues regarding the basic WCE operation, the MAGLEV-based control system, the method of phase-lead compensation, the power amplifier circuit, and the electromagnetic coil design in controllable WCE are reviewed and discussed.