Use of a 3-D Wireless Power Transfer Technique as a Method for Capsule Localization

Capsule endoscopy has been heralded as a technological milestone in the diagnosis and therapeutics of gastrointestinal (GI) pathologies. The location and position of the capsule within the GI tract are important information for subsequent surgical intervention or local drug delivery. Accurate information of capsule location is therefore required during endoscopy. Although radio frequency (RF)-based, magnetic tracking and video localization have been investigated in the past, the complexity of those systems and potential inaccuracy in the localization data necessitate the scope for further research. This article proposes the dual use of a wireless power transfer (WPT) configuration as a method to enable the determination of the location of an endoscopic capsule. Measurements conducted on a homogeneous agar-based liquid phantom predict a maximum error of 12% between the calculated and measured trajectories of the capsule in a working volume of 100 mm $\times 100$ mm $\times 100$ mm

Enhanced Localization of Robotic Capsule Endoscopes Using Positron Emission Markers and Rigid-Body Transformation

Using positron emission markers for the localization of a robotic capsule endoscope is promising because it does not require onboard space or built-in battery for operation. Further, its compatibility with magnetic actuation is another significant advantage compared with conventional magnetic localization methods reported in the literature. In this paper, we propose a new tracking algorithm based on rigid-body transformation and gamma rays emitted from three positron emission markers onboard to localize an endoscopic capsule operating within the gastrointestinal tract of the human body. Different from traditional rigid-body transformation based on datasets of 3-D points, our method estimates the transformation parameters (e.g., translation vector and rotation angle) from several groups of 3-D lines in order to determine the locations of the markers emitting the gamma rays. Validated by both simulation data using a voxelized phantom in the Geant4 Application for Emission Tomography toolkit and the experimental data collected from a positron emission tomography scanner, the new localization method shows a significant improvement in the tracking accuracy (an average position error of 0.4 mm and orientation error of 1.9 & #x00B0;) and the failure rate (18/9600 localization runs), compared to the localization results reported in the literature