Design and verification of a flexible device for steering a tethered capsule endoscope in the stomach

Abstract

Capsule endoscopy is a good method of gastric cancer diagnosis that has some advantages over conventional endoscopy, such as providing reliable results without substantial discomfort to patients. However, lack of capsule motion control has been a significant obstacle preventing wider application of this technology. To overcome this problem, this paper proposes a steering device that can be employed to manipulate the capsule of a tethered capsule endoscope (TCE) omni-directionally. The TCE system can be swallowed by patients with minimal discomfort because of its small size and the flexibility of its tether. The proposed device consists of an actuator section containing three linear actuators, a thin and flexible tether, and a retractable capsule base. It provides control during reconfiguration in a large workspace while maintaining the flexibility of the tether. The results of workspace calibration demonstrate that, when the capsule is fully deployed to a distance of 40 mm, it can be adjusted to angles covering 360° radially and up to 110° axially. A proof-of-concept setup with a spherical phantom stomach was employed to validate the effectiveness of the steering device.