5-DOF Manipulation of a Magnetic Capsule in Fluid using a Single Permanent Magnet: Proof-of-Concept for Stomach Endoscopy

Magnetic manipulation of capsule endoscopes has the potential to make current gastrointestinal screening procedures faster, safer, and less invasive. To date, two electromagnetic systems have been developed with the ability to perform five-degree-of-freedom (5-DOF) manipulation of an untethered magnetic device such as a magnetic capsule endoscope: the OctoMag system consists of eight electromagnets arranged around a hemisphere directed toward the manipulation workspace [1]; a system has been developed by Siemens, consisting of 12 electromagnets through which a patient is positioned, for the control of a capsule endoscope in a water-filled stomach [2]. Permanent-magnet actuation systems are gaining attention for their ability to generate fields with clinically relevant strengths, inexpensively and in a compact form-factor, compared to electromagnetic systems. Previous permanent-magnet systems for capsule endoscopy have been limited to dragging and rolling capsule endoscope devices on the stomach’s surface or in the large colon [3–5]. This proof-of-concept paper demonstrates magnetic 3-DOF position and 2-DOF orientation control of a mockup stomach capsule endoscope in fluid, using a single permanent magnet. 5-DOF manipulation of untethered devices has been previously demonstrated only with electromagnet systems.