# Tracking the Traveled Distance of Capsule Endoscopes along a Gastrointestinal-Tract Model Using Differential Static Magnetic Localization

^{*}

## Abstract

**:**

## 1. Introduction

## 2. Methods

#### 2.1. Differential Static Magnetic Tracking

#### 2.2. Experimental Setup

#### 2.3. Evaluation Procedure

## 3. Results

## 4. Discussion

## 5. Conclusions

## Author Contributions

## Funding

## Institutional Review Board Statement

## Informed Consent Statement

## Data Availability Statement

## Conflicts of Interest

## References

- Flemming, J.; Cameron, S. Small bowel capsule endoscopy. Medicine
**2018**, 97, e0148. [Google Scholar] [CrossRef] [PubMed] - Fillit, H.M.; Rockwood, K.; Young, J.B. Brocklehurst’s Textbook of Geriatric Medicine and Gerontology; Elsevier Health Textbook; Elsevier: Amsterdam, The Netherlands, 2016. [Google Scholar]
- Dimas, G.; Spyrou, E.; Iakovidis, D.K.; Koulaouzidis, A. Intelligent visual localization of wireless capsule endoscopes enhanced by color information. Comput. Biol. Med.
**2017**, 89, 429–440. [Google Scholar] [CrossRef] [PubMed] - Aoki, T.; Yamada, A.; Kato, Y.; Saito, H.; Tsuboi, A.; Nakada, A.; Niikura, R.; Fujishiro, M.; Oka, S.; Ishihara, S.; et al. Automatic detection of various abnormalities in capsule endoscopy videos by a deep learning-based system: A multicenter study. Gastrointest. Endosc.
**2021**, 93, 165–173.e1. [Google Scholar] [CrossRef] [PubMed] - Marya, N.; Karellas, A.; Foley, A.; Roychowdhury, A.; Cave, D. Computerized 3-dimensional localization of a video capsule in the abdominal cavity: Validation by digital radiography. Gastrointest. Endosc.
**2014**, 79, 669–674. [Google Scholar] [CrossRef][Green Version] - Mateen, H.; Basar, R.; Ahmed, A.U.; Ahmad, M.Y. Localization of Wireless Capsule Endoscope: A Systematic Review. IEEE Sens. J.
**2017**, 17, 1197–1206. [Google Scholar] [CrossRef] - Bianchi, F.; Masaracchia, A.; Shojaei Barjuei, E.; Menciassi, A.; Arezzo, A.; Koulaouzidis, A.; Stoyanov, D.; Dario, P.; Ciuti, G. Localization strategies for robotic endoscopic capsules: A review. Expert Rev. Med. Devices
**2019**, 16, 381–403. [Google Scholar] [CrossRef] - Figueiredo, I.N.; Leal, C.; Pinto, L.; Figueiredo, P.N.; Tsai, R. Hybrid multiscale affine and elastic image registration approach towards wireless capsule endoscope localization. Biomed. Signal Process. Control
**2018**, 39, 486–502. [Google Scholar] [CrossRef] - Iakovidis, D.K.; Dimas, G.; Karargyris, A.; Bianchi, F.; Ciuti, G.; Koulaouzidis, A. Deep Endoscopic Visual Measurements. IEEE J. Biomed. Health Inform.
**2019**, 23, 2211–2219. [Google Scholar] [CrossRef] - Vedaei, S.S.; Wahid, K.A. A localization method for wireless capsule endoscopy using side wall cameras and IMU sensor. Sci. Rep.
**2021**, 11, 11204. [Google Scholar] [CrossRef] - Song, S.; Wang, S.; Yuan, S.; Wang, J.; Liu, W.; Meng, M.Q.H. Magnetic Tracking of Wireless Capsule Endoscope in Mobile Setup Based on Differential Signals. IEEE Trans. Instrum. Meas.
**2021**, 70, 1–8. [Google Scholar] [CrossRef] - Dai, H.; Hu, C.; Su, S.; Lin, M.; Song, S. Geomagnetic Compensation for the Rotating of Magnetometer Array During Magnetic Tracking. IEEE Trans. Instrum. Meas.
**2019**, 68, 3379–3386. [Google Scholar] [CrossRef] - Shao, G.; Tang, Y.; Tang, L.; Dai, Q.; Guo, Y.X. A Novel Passive Magnetic Localization Wearable System for Wireless Capsule Endoscopy. IEEE Sens. J.
**2019**, 19, 3462–3472. [Google Scholar] [CrossRef] - Wang, M.; Song, S.; Liu, J.; Meng, M.Q.H. Multipoint Simultaneous Tracking of Wireless Capsule Endoscope Using Magnetic Sensor Array. IEEE Trans. Instrum. Meas.
**2021**, 70, 7502510. [Google Scholar] [CrossRef] - Islam, M.N.; Fleming, A.J. Resonance-Enhanced Coupling for Range Extension of Electromagnetic Tracking Systems. IEEE Trans. Magn.
**2018**, 54, 1–9. [Google Scholar] [CrossRef] - Glaser, R. Biophysics, 1st ed.; Springer: Berlin/Heidelberg, Germany, 2000. [Google Scholar]
- Zeising, S.; Ararat, K.; Thalmayer, A.; Anzai, D.; Fischer, G.; Kirchner, J. Systematic Performance Evaluation of a Novel Optimized Differential Localization Method for Capsule Endoscopes. Sensors
**2021**, 21, 3180. [Google Scholar] [CrossRef] - Zeising, S.; Thalmayer, A.; Fischer, G.; Kirchner, J. Differential Geomagnetic Compensation Method for the Static Magnetic Localization of Capsule Endoscopes during Activities of the Daily Life. IEEE Trans. Instrum. Meas.
**2022**, 71, 1–10. [Google Scholar] [CrossRef] - Wang, M.; Shi, Q.; Song, S.; Hu, C.; Meng, M.Q.H. A Novel Relative Position Estimation Method for Capsule Robot Moving in Gastrointestinal Tract. Sensors
**2019**, 19, 2746. [Google Scholar] [CrossRef][Green Version] - Su, S.; Yang, W.; Dai, H.; Xia, X.; Lin, M.; Sun, B.; Hu, C. Investigation of the Relationship Between Tracking Accuracy and Tracking Distance of a Novel Magnetic Tracking System. IEEE Sens. J.
**2017**, 17, 4928–4937. [Google Scholar] [CrossRef] - Hounnou, G.; Destrieux, C.; Desmé, J.; Velut, P.B.S. Anatomical study of the length of the human intestine. Surg. Radiol. Anat.
**2002**, 24, 290–294. [Google Scholar] [CrossRef] - Jackson, J.D. Classical Electrodynamics, 1st ed.; Wiley: New York, NY, USA, 1962. [Google Scholar]
- Zeising, S.; Anzai, D.; Thalmayer, A.; Fischer, G.; Kirchner, J. Evaluation of the Impact of Static Interference on an Empirical Data Based Static Magnetic Localization Setup for Capsule Endoscopy. Curr. Dir. Biomed. Eng.
**2020**, 6, 66–69. [Google Scholar] [CrossRef] - Merayo, J.; Brauer, P.; Primdahl, F.; Petersen, J.; Nielsen, O. Scalar Calibration of Vector Magnetometers. Meas. Sci. Technol.
**2000**, 11, 120–132. [Google Scholar] [CrossRef]

**Figure 1.**Schematic of the system design using the differential method to track the traveled distance of a capsule endoscope within the gastrointestinal tract.

**Figure 2.**Localisation setup with the 12 sensors centered within the sensor mounts. The coordinate system of the setup is in its centre. The printed trajectory with the 10 × 10 mm magnet was exemplarily placed at the $z=0$ mm plane.

**Figure 3.**Schematic of the evaluation procedure for calculating the mean and standard deviation (STD) of the relative distance error and orientation error for each magnet, and its corresponding orientation.

**Figure 4.**Mean and standard deviation values for relative traveled distance errors for different magnets and orientations. For the 5 and 3 mm long magnets, cases where the magnetisation was in parallel with the moving direction were not conducted.

**Figure 5.**Representative measured trajectories using the 10 × 10 mm magnet while its magnetisation was perpendicular to the movement direction.

**Figure 6.**Mean and standard deviation values of orientation errors for magnets along the trajectory in perpendicular orientation to the moving direction.

**Table 1.**Comparison with state-of-the-art capsule endoscopy tracking methods. The occupied space is specified with respect to the assumed typical size of commercial capsules of 33 × 12 mm (length × diameter).

Method | Trajectory | Occ. Space (%) | Rel. Error (%) | Or. Error (${}^{\circ}$) | |
---|---|---|---|---|---|

This work: | |||||

10 mm magnet | Diff. static magnetic | Curved 3D (487.5 mm) | 21.0 | 2.7 | 1.7 |

5 mm magnet | Diff. static magnetic | Curved 3D (487.5 mm) | 10.5 | 4.3 | 2.0 |

3 mm magnet | Diff. static magnetic | Curved 3D (487.5 mm) | 6.3 | 11.9 | 3.6 |

State of the art: | |||||

[19] (2019) | Static magnetic | Curved 3D (840 mm) | not stated | 5.7 | - |

[18] (2021) | Diff. static magnetic | Linear (109 mm) | 21.0 | 3.1 | 2.7 |

[9] (2019) | Video | Linear (200 mm) | 0 | 6.0 | - |

[10] (2021) | Video/Inertial unit | Linear (600 mm) | >100 | 3.7 | - |

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. |

© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

## Share and Cite

**MDPI and ACS Style**

Zeising, S.; Chen, L.; Thalmayer, A.; Lübke, M.; Fischer, G.; Kirchner, J.
Tracking the Traveled Distance of Capsule Endoscopes along a Gastrointestinal-Tract Model Using Differential Static Magnetic Localization. *Diagnostics* **2022**, *12*, 1333.
https://doi.org/10.3390/diagnostics12061333

**AMA Style**

Zeising S, Chen L, Thalmayer A, Lübke M, Fischer G, Kirchner J.
Tracking the Traveled Distance of Capsule Endoscopes along a Gastrointestinal-Tract Model Using Differential Static Magnetic Localization. *Diagnostics*. 2022; 12(6):1333.
https://doi.org/10.3390/diagnostics12061333

**Chicago/Turabian Style**

Zeising, Samuel, Lu Chen, Angelika Thalmayer, Maximilian Lübke, Georg Fischer, and Jens Kirchner.
2022. "Tracking the Traveled Distance of Capsule Endoscopes along a Gastrointestinal-Tract Model Using Differential Static Magnetic Localization" *Diagnostics* 12, no. 6: 1333.
https://doi.org/10.3390/diagnostics12061333