Hironao Kawano

Magnetic Actuator for a Capsule Endoscope Navigation System

A gastrointestinal (GI) endoscopy is widely carried out in order to find diseases at their early stages. A capsule endoscope is proposed for inspection by swallowing. The capsule moves passively through GI tract with the aid of peristalsis. In previous studies, the effect of GI tracts spiral structure on moving properties of a capsule-type magnetic actuator has been reported. In addition, it was reported that the actuator can pass though an intestine extracted from a pig. In this study, the effect of the spiral structure on the velocity and on the thrust force properties of the actuators were examined using silicone tube as a phantom. If a spiral angle and number of spirals are different, the velocity and the thrust force are varied. Results show that when the spiral angle is 45 degree, the number of spirals is 4, and the spiral height is 1-mm/spl phi/, the velocity and the thrust force had maximum value. A moving test for a capsule-type magnetic actuator was also examined in the pigs large intestine on the slope. It took 300 seconds for the large intestine to pass through to the other end. In addition, the actuator could pass on the slope of 30 degree without a hitch. These results shows that the magnetic actuator has great potential for a navigation system of a capsule endoscope.