A discrete-time localization method for capsule endoscopy based on on-board magnetic sensing

Abstract

Recent achievements in active capsule endoscopy have allowed controlled inspection of the bowel by magnetic guidance. Capsule localization represents an important enabling technology for such kinds of platforms. In this paper, the authors present a localization method, applied as first step in time-discrete capsule position detection, that is useful for establishing a magnetic link at the beginning of an endoscopic procedure or for re-linking the capsule in the case of loss due to locomotion. The novelty of this approach consists in using magnetic sensors on board the capsule whose output is combined with pre-calculated magnetic field analytical model solutions. A magnetic field triangulation algorithm is used for obtaining the position of the capsule inside the gastrointestinal tract. Experimental validation has demonstrated that the proposed procedure is stable, accurate and has a wide localization range in a volume of about 18 × 10 3 cm 3. Position errors of 14 mm along the X direction, 11 mm along the Y direction and 19 mm along the Z direction were obtained in less than 27 s of elaboration time. The proposed approach, being compatible with magnetic fields used for locomotion, can be easily extended to other platforms for active capsule endoscopy.

From Passive Tool Holders to Microsurgeons: Safer, Smaller, Smarter Surgical Robots

“…Capsule endoscopes coupled with thermally actuated nanogrippers can perform localised biopsies [117] and wireless colon insuflation [118], or deliver drugs [37]. The capsules can be localised within the body by exploiting the magnetic field they produce [119], [120] or by ultrasound imaging [121], and can, thus, be servoed to the desired anatomical sites. Recent technological advances by Ishiyama et al and Abbott et al demonstrate that screw-like capsules can burrow in tissue, thus expanding their operational capabilities [122], [123].…”

5-DOF Manipulation of an Untethered Magnetic Device in Fluid using a Single Permanent Magnet

“…Existing clinically relevant localization strategies include RF triangulation [11], magnetic methods [7,19,21,23], and CT scan or x-ray fluoroscopy [8]. In the previous experiments, the mockup capsule's position was localized at 90 Hz by the vision system.…”

Intra-operative monocular 3D reconstruction for image-guided navigation in active locomotion capsule endoscopy

“…In a real scenario the endoscopic device will be accurately steered in according to the calculated trajectory by means of a robotic-assisted magnetic propulsion [5], [6], closing the capsule control motion loop throughout a highly precise localization strategy, such as the one proposed by the author in [28].…”

“…In this framework the capsule would be reliably steered in according to the calculated trajectory by means of a roboticassisted magnetic propulsion [6] and controlled exploiting a highly precise localization, such as the one proposed by the author in [28], making the strategy assumptions not so far from a real scenario.…”