Capsule endoscope and double-balloon endoscope are representative enteroscopes. However, it is difficult to use these endoscopes in patients with intestinal obstruction and adhesion. We developed a new enteroscope that can be used in patients with intestinal obstruction and adhesion; this instrument consists of an ileus tube and an optical fiberscope (diameter, 1.1 mm). When this enteroscope removed from the body, one can observe the small intestine by controlling the internal pressure of a balloon of the ileus tube as maintaining a bowel adequately. We devised a control unit to sufficiently control the internal pressure of the balloon for enabling observation of the whole area of the small intestine, and performed a basic experiment. The experimental results revealed that in a step response, the control accuracy was 0.05-0.15 kPa without an overshoot. Further, in a disturbance response, in comparison with a case without control, a one-20th was able to decrease pressure fluctuation. In addition, we performed a pulling test using an ileus tube and a small intestine model, and confirmed that we might pull out an ileus tube at constant speed by controlling the fluctuations in the internal pressure of the balloon.
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