Positioning and Posture Adjustment for a Rotational Cutting Biopsy Capsule

Capsule endoscopy has become a popular method for the diagnosis of colorectal disease because of its small size and friendly interactive performance. Capsule endoscopy has integrated biopsy function to improve diagnostic ability beyond only imaging. However, the randomness of pathological tissue distribution in the intestine requires the accuracy of positioning and attitude adjustment of the capsule endoscopy during sampling. Herein, accurate attitude adjustment is more challenging. In this paper, based on the magnetic charge model, a method that can control the position and posture of the capsule is proposed, referring to the modeling and simulation of the magnetic field distribution of the permanent magnet. Experiments based on the motion model of the biopsy capsule were used to study reciprocating linear motion and circumferential posture adjustment. The experimental results show that the proposed method can effectively control the biopsy capsule to achieve the desired position and posture to meet the requirement of sampling the inner intestine.