A Robust Magnetic Localization Method for Wearable Capsule Endoscopy Systems Compatible with Daily Life Activities

Zeising, Samuel

• Publisher: Cuvillier Verlag
• Year: 2023
• eBook ISBN:
  9783736967656
• Print ISBN:
  9783736977655
• Edition: 1

The localization of capsule endoscopes is essential for a reliable diagnosis. However, the current state of the art does not offer a suitable method for locating the capsules with sufficient accuracy during the daily life. Therefore, in this work, a robust magnetic localization method was developed. For this purpose, a small magnet was integrated into the capsules and its magnetic field was measured using a sensor array. The geomagnetic field is superimposed on the field of the magnet, which is why a differential localization method was applied. In addition, two coils were placed around the abdomen, which served as reference objects for locating the capsule. Thus, relative movement between the sensor array and the abdomen, and the geomagnetic field were compensated. The added value compared to the state of the art concerning the robustness in daily life situations was proven because the position and orientation errors were less than 6 mm and 5°, respectively.Zur verlässlichen Diagnose ist die Lokalisierung von Kapselendoskopen essentiell. Der aktuelle Stand der Technik bietet jedoch keine geeignete Methode, um die Kapseln während des alltäglichen Lebens mit hinreichender Genauigkeit zu orten. Deshalb wurde in dieser Arbeit eine magnetische Lokalisierungsmehthode entwickelt, welche robust in Alltagssituationen ist. Dazu wurde ein kleiner Magnet in die Kapseln integriert und dessen Magnetfeld wurde mittels eines Sensorarrays gemessen. Das Erdmagnetfeld überlagert sich mit dem Feld des Magneten, weshalb ein differentieller Algorithmus entworfen wurde. Außerdem wurden zwei Spulen um das Abdomen angeordnet, die als Referenzobjekte zur Lokalisierung der Kapsel dienten. Somit wurde relative Bewegung zwischen Sensorarray und dem Abdomen und das Erdmagnetfeld kompensiert. Der Mehrwert zum Stand der Technik bezüglich der Robust in Alltagssituationen wurde bewiesen, denn der Positions- und Orientierungsfehler waren kleiner als 6 mm, respektive 5°.

Table of contents

• Kurzfassung
• Abstract
• 1 Introduction
• 1.1 Publications
• 1.2 Endoscopy of the Gastrointestinal Tract
• 1.3 Research Problem
• 2 State of the Art in Localization of Capsule Endoscopes (CE)
• 2.1 Scientific Approaches
• 2.2 Commercial Approaches
• 2.3 Discussion of the State of the Art in Localization of CE
• 3 Aim of the Thesis
• 4 Applied Strategy and Used Methods
• 4.1 Differential Static Magnetic Localization for Integrationwith a Wearable CE System
• 4.2 Relative Movement Compensation for the Proposed Differential Method for Integration with a Wearable CE System
• 5 Results and Discussion
• 5.1 Evaluation of Differential Geomagnetic Compensation
• 5.2 Evaluation of Relative Movement Compensation Method
• 5.3 Summary of Contributions to Static Magnetic Localization of CE
• 5.4 Summary of Contributions to Localization of CE
• 6 Conclusion and Prospect
• References
• List of Abbrevia􀆟ons
• Tables and Figures
• Danksagung
• List of Own Publications
• List of Supervised Student Theses