Experimental measurement on movement of spiral-type capsule endoscope.

Wireless capsule endoscope achieved great success, however, the maneuvering of wireless capsule endoscope is challenging at present. A magnetic driving instrument, including two bar magnets, a stepper motor, a motor driver, a motor controller, and a power supplier, was developed to generate rotational magnetic fields. Permanent magnet ring, magnetized as S and N poles radially and mounted spiral structure on the surface, acted as a capsule.

Localization for robotic capsule looped by axially magnetized permanent-magnet ring based on hybrid strategy.

To actively maneuver a robotic capsule for interactive diagnosis in the gastrointestinal tract, visualizing accurate position and orientation of the capsule when it moves in the gastrointestinal tract is essential. A possible method that encloses the circuits, batteries, imaging device, etc into the capsule looped by an axially magnetized permanent-magnet ring is proposed. Based on expression of the axially magnetized permanent-magnet ring's magnetic fields, a localization and orientation model was established.

Investigation of a cuboidal permanent magnet's force exerted on a robotic capsule.

To control and drive a robotic capsule accurately from outside a patient's body, we present a schema in which the capsule enclosing the imaging device, circuits, batteries, etc is looped by a permanent magnet ring that acts as an actuator. A cuboidal permanent magnet situated outside the patient's body attracts or pushes the magnet ring from different directions to make the capsule move or rotate. A mathematic model of attractive or repulsive force that the cuboidal magnet exerts on the magnet ring is presented for accurate calculation of force.

An improved magnetic localization and orientation algorithm for wireless capsule endoscope.

In this paper, we propose a novel localization algorithm for tracking a magnet inside the capsule endoscope by 3-axis magnetic sensors array. In the algorithm, we first use an improved linear algorithm to obtain the localization parameters by finding the eigenvector corresponding to the minimum eigenvalue of the objective matrix. These parameters are used as the initial guess of the localization parameters in the nonlinear localization algorithm, and the nonlinear algorithm searches for more appropriate parameters that can minimize the objective error function.