scholarly journals Innovative Differential Magnetic Localization Method for Capsule Endoscopy to Prevent Interference Caused by the Geomagnetic Field

2021 ◽  
Vol 19 ◽  
pp. 207-213
Author(s):  
Samuel Zeising ◽  
Daisuke Anzai ◽  
Angelika Thalmayer ◽  
Georg Fischer ◽  
Jens Kirchner
Keyword(s):  
Capsule Endoscopy ◽  
Geomagnetic Field ◽  
Medical Application ◽  
Differential Method ◽  
Localization Accuracy ◽  
Localization Method ◽  
Marquardt Algorithm ◽  
Capsule Endoscopes ◽  
Position And Orientation ◽  
The Impact

Abstract. Wireless capsule endoscopy is an established medical application for the examination of the gastrointestinal tract. However, the robust and precise localization of these capsules is still in need of further scientific investigation. This paper presents an innovative differential magnetic localization method for capsule endoscopy to prevent interference caused by the geomagnetic field. The effect of changing the orientation of the capsule on the localization process was also examined. Simulations using COMSOL Multiphysics with the superimposed geomagnetic field were performed. The Levenberg–Marquardt algorithm was applied in MATLAB to estimate the position and orientation of the capsule. Comparing the proposed differential method with the absolute magnetic localization method under ideal conditions, the mean position and orientation errors were reduced by three orders in magnitude to less than 0.1 mm and 0.1∘ respectively. Even if sensor non-idealities are considered, the simulation-based results reveal that our proposed method is competitive with state-of-the-art geomagnetic compensation methods for static magnetic localization of capsule endoscopes. The achieved localization accuracy by applying the differential method is not dependent on the rotation of the localization system relative to the geomagnetic flux density under the made assumptions and the impact of the magnet orientation is neglectable. It is concluded that the proposed method is capable of preventing all interference whose components are approximately equal at all sensors with identical orientation.

scholarly journals Innovative Differential Magnetic Localization Method for Capsule Endoscopy to Prevent Interference Caused by the Geomagnetic Field

2021 ◽  
Author(s):  
Samuel Zeising ◽  
Daisuke Anzai ◽  
Angelika Thalmayer ◽  
Georg Fischer ◽  
Jens Kirchner
Keyword(s):  
Capsule Endoscopy ◽  
Geomagnetic Field ◽  
Medical Application ◽  
Differential Method ◽  
Localization Accuracy ◽  
Localization Method ◽  
Marquardt Algorithm ◽  
Position And Orientation ◽  
Wireless Capsule ◽  
The Impact

Wireless capsule endoscopy is an established medical application for the examination of the gastrointestinal tract. However, the robust and precise localization of these capsules is still in need of further scientific investigation. This paper presents an innovative differential magnetic localization method for capsule endoscopy to prevent interference caused by the geomagnetic field. The effect of changing the orientation of the capsule on the localization process was also examined. Simulations using COMSOL Multiphysics with the superimposed geomagnetic field were performed. The Levenberg–Marquardt algorithm was applied in MATLAB to estimate the position and orientation of the capsule. Comparing the proposed differential method with the absolute magnetic localization method under ideal conditions, the mean position and orientation errors were reduced by three orders in magnitude to less than 0.1 mm and 0.1 ° respectively. Even if sensor non-idealities are considered, the simulationbased results reveal that our proposed method is competitive with state-of-the-art geomagnetic compensation methods for static magnetic localization of capsule endoscopes.The achieved localization accuracy by applying the differential method is not dependent on the rotation of the localization system relative to the geomagnetic flux density under the made assumptions and the impact of the magnet orientation is neglectable. It is concluded that the proposed method is capable of preventing all interference whose components are approximately equal at all sensors with identical orientation. <br>

scholarly journals Innovative Differential Magnetic Localization Method for Capsule Endoscopy to Prevent Interference Caused by the Geomagnetic Field

2021 ◽  
Author(s):  
Samuel Zeising ◽  
Daisuke Anzai ◽  
Angelika Thalmayer ◽  
Georg Fischer ◽  
Jens Kirchner
Keyword(s):  
Capsule Endoscopy ◽  
Geomagnetic Field ◽  
Medical Application ◽  
Differential Method ◽  
Localization Accuracy ◽  
Localization Method ◽  
Marquardt Algorithm ◽  
Position And Orientation ◽  
Wireless Capsule ◽  
The Impact

Wireless capsule endoscopy is an established medical application for the examination of the gastrointestinal tract. However, the robust and precise localization of these capsules is still in need of further scientific investigation. This paper presents an innovative differential magnetic localization method for capsule endoscopy to prevent interference caused by the geomagnetic field. The effect of changing the orientation of the capsule on the localization process was also examined. Simulations using COMSOL Multiphysics with the superimposed geomagnetic field were performed. The Levenberg–Marquardt algorithm was applied in MATLAB to estimate the position and orientation of the capsule. Comparing the proposed differential method with the absolute magnetic localization method under ideal conditions, the mean position and orientation errors were reduced by three orders in magnitude to less than 0.1 mm and 0.1 ° respectively. Even if sensor non-idealities are considered, the simulationbased results reveal that our proposed method is competitive with state-of-the-art geomagnetic compensation methods for static magnetic localization of capsule endoscopes.The achieved localization accuracy by applying the differential method is not dependent on the rotation of the localization system relative to the geomagnetic flux density under the made assumptions and the impact of the magnet orientation is neglectable. It is concluded that the proposed method is capable of preventing all interference whose components are approximately equal at all sensors with identical orientation. <br>

scholarly journals Evaluation of the Impact of Static Interference on an Empirical Data Based Static Magnetic Localization Setup for Capsule Endoscopy

2020 ◽  
Vol 6 (3) ◽  
pp. 66-69
Author(s):  
Samuel Zeising ◽  
Daisuke Anzai ◽  
Angelika Thalmayer ◽  
Georg Fischer ◽  
Jens Kirchner
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Capsule Endoscopy ◽  
Empirical Data ◽  
Geomagnetic Field ◽  
Sensor Array ◽  
Magnetic Flux Density ◽  
Wearable Sensor ◽  
Differential Measurement ◽  
The Impact

AbstractIn this paper, the impact of interference due to the geomagnetic field on a static magnetic localization setup for capsule endoscopy, which is suitable for a wearable application, was investigated. For this purpose, a study was carried out in which the average abdomen size of 15 subjects was evaluated. With the determined geometry values, a setup consisting of three elliptical sensor rings was modeled. Simulations were performed, where the magnetic flux density was evaluated at the sensors by using different-sized magnets. The measured values were compared with each other and the geomagnetic flux density. The results revealed that the measured values were for all evaluated magnet sizes of the order of the geomagnetic flux density, which is problematic since the calibration of sensors is no longer valid if the orientation of the wearable sensor array is changed. However, it is suggested that a differential measurement is suitable for the proposed system and could reduce static interference caused by the geomagnetic field.

scholarly journals Modular Approach for Odometry Localization Method for Vehicles with Increased Maneuverability

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 79
Author(s):  
Chenlei Han ◽  
Michael Frey ◽  
Frank Gauterin
Keyword(s):  
Steering System ◽  
Vehicle Control ◽  
Modular Approach ◽  
Route Guidance ◽  
State Variables ◽  
Simulation Environment ◽  
Localization Method ◽  
State Estimators ◽  
Position And Orientation ◽  
Guidance Information

Localization and navigation not only serve to provide positioning and route guidance information for users, but also are important inputs for vehicle control. This paper investigates the possibility of using odometry to estimate the position and orientation of a vehicle with a wheel individual steering system in omnidirectional parking maneuvers. Vehicle models and sensors have been identified for this application. Several odometry versions are designed using a modular approach, which was developed in this paper to help users to design state estimators. Different odometry versions have been implemented and validated both in the simulation environment and in real driving tests. The evaluated results show that the versions using more models and using state variables in models provide both more accurate and more robust estimation.

scholarly journals An Improved Localization Method for the Transition between Autonomous Underwater Vehicle Homing and Docking

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2468
Author(s):  
Ri Lin ◽  
Feng Zhang ◽  
Dejun Li ◽  
Mingwei Lin ◽  
Gengli Zhou ◽  
...  
Keyword(s):  
Data Exchange ◽  
Autonomous Underwater Vehicle ◽  
Autonomous Underwater Vehicles ◽  
Optimization Method ◽  
Short Baseline ◽  
Localization Accuracy ◽  
Localization Method ◽  
Mapping Algorithm ◽  
Localization And Mapping ◽  
Update Rate

Docking technology for autonomous underwater vehicles (AUVs) involves energy supply, data exchange and navigation, and plays an important role to extend the endurance of the AUVs. The navigation method used in the transition between AUV homing and docking influences subsequent tasks. How to improve the accuracy of the navigation in this stage is important. However, when using ultra-short baseline (USBL), outliers and slow localization updating rates could possibly cause localization errors. Optical navigation methods using underwater lights and cameras are easily affected by the ambient light. All these may reduce the rate of successful docking. In this paper, research on an improved localization method based on multi-sensor information fusion is carried out. To improve the localization performance of AUVs under motion mutation and light variation conditions, an improved underwater simultaneous localization and mapping algorithm based on ORB features (IU-ORBSALM) is proposed. A nonlinear optimization method is proposed to optimize the scale of monocular visual odometry in IU-ORBSLAM and the AUV pose. Localization tests and five docking missions are executed in a swimming pool. The localization results indicate that the localization accuracy and update rate are both improved. The 100% successful docking rate achieved verifies the feasibility of the proposed localization method.

Method of Optimization for Target Localization Model Parameters Based on LSSVR

2011 ◽  
Vol 268-270 ◽  
pp. 934-939
Author(s):  
Xue Wen He ◽  
Gui Xiong Liu ◽  
Hai Bing Zhu ◽  
Xiao Ping Zhang
Keyword(s):  
Particle Swarm Optimization ◽  
Fitness Function ◽  
Particle Swarm ◽  
Parameters Optimization ◽  
Target Localization ◽  
Likelihood Method ◽  
Support Vector ◽  
Swarm Optimization ◽  
Localization Accuracy ◽  
Localization Method

Aiming at improving localization accuracy in Wireless Sensor Networks (WSN) based on Least Square Support Vector Regression (LSSVR), making LSSVR localization method more practicable, the mechanism of effects of the kernel function for target localization based on LSSVR is discussed based on the mathematical solution process of LSSVR localization method. A novel method of modeling parameters optimization for LSSVR model using particle swarm optimization is proposed. Construction method of fitness function for modeling parameters optimization is researched. In addition, the characteristics of particle swarm parameters optimization are analyzed. The computational complexity of parameters optimization is taken into consideration comprehensively. Experiments of target localization based on CC2430 show that localization accuracy using LSSVR method with modeling parameters optimization increased by 23%~36% in compare with the maximum likelihood method(MLE) and the localization error is close to the minimum with different LSSVR modeling parameters. Experimental results show that adapting a reasonable fitness function for modeling parameters optimization using particle swarm optimization could enhance the anti-noise ability significantly and improve the LSSVR localization performance.

scholarly journals Multi-Focal Vision and Gaze Control Improve Navigation Performance

10.5772/50920 ◽  
2012 ◽  
Vol 9 (1) ◽  
pp. 25 ◽  
Author(s):  
Kolja Kühnlenz ◽  
Martin Buss
Keyword(s):  
Mobile Robot ◽  
Robot Navigation ◽  
Active Vision ◽  
Path Following ◽  
Mobile Robot Navigation ◽  
Vision Systems ◽  
Localization Accuracy ◽  
Localization And Mapping ◽  
Novel Concept ◽  
The Impact

Multi-focal vision systems comprise cameras with various fields of view and measurement accuracies. This article presents a multi-focal approach to localization and mapping of mobile robots with active vision. An implementation of the novel concept is done considering a humanoid robot navigation scenario where the robot is visually guided through a structured environment with several landmarks. Various embodiments of multi-focal vision systems are investigated and the impact on navigation performance is evaluated in comparison to a conventional mono-focal stereo set-up. The comparative studies clearly show the benefits of multi-focal vision for mobile robot navigation: flexibility to assign the different available sensors optimally in each situation, enhancement of the visible field, higher localization accuracy, and, thus, better task performance, i.e. path following behavior of the mobile robot. It is shown that multi-focal vision may strongly improve navigation performance.

scholarly journals Geomagnetic field disturbances from the fall of the Lipetsk (june 21, 2018) and Chelyabinsk (february 15, 2013) meteorites

2019 ◽  
Vol 485 (3) ◽  
pp. 361-365
Author(s):  
A. A. Spivak ◽  
S. A. Riabova
Keyword(s):  
Delay Time ◽  
Geomagnetic Field ◽  
Maximum Effect ◽  
Impact Point ◽  
Cosmic Body ◽  
Meteorite Impact ◽  
Geomagnetic Disturbances ◽  
Geophysical Observatory ◽  
Earth’S Atmosphere ◽  
The Impact

Based on the Chelyabinsk (February 13, 2013) and Lipetsk (June 21, 2018) events, disturbances in the Earth's geomagnetic field, which were induced by the fall of these meteorites, were studied. Based on the data provided by geomagnetic observatories of the INTERMAGNET network and the mid-latitude Mikhnevo geophysical observatory (IDG RAS), it was established that the fall of meteorites through the Earth's atmosphere, in general, induces geomagnetic disturbances of up to 5 nT at distances up to 2700 km from the impact point of a cosmic body; the maximum effect is reached with a delay time ranging from ~5 to ~10 min, and the duration of the period of the induced geomagnetic field disturbances varies from ~5 to ~20 min. The estimation dependencies of the amplitude and duration of induced geomagnetic disturbances from a distance from the meteorite impact points are proposed.

scholarly journals Patient-specific optimization of automated detection improves seizure onset zone localization based on high frequency oscillations

2020 ◽  
Author(s):  
Casey L. Trevino ◽  
Jack J. Lin ◽  
Indranil Sen-Gupta ◽  
Beth A. Lopour
Keyword(s):  
High Frequency ◽  
Classification Accuracy ◽  
Patient Specific ◽  
Seizure Onset ◽  
Data Set ◽  
Localization Accuracy ◽  
High Frequency Oscillations ◽  
Seizure Onset Zone ◽  
Wide Range ◽  
The Impact

AbstractHigh frequency oscillations (HFOs) are a promising biomarker of epileptogenicity, and automated algorithms are critical tools for their detection. However, previously validated algorithms often exhibit decreased HFO detection accuracy when applied to a new data set, if the parameters are not optimized. This likely contributes to decreased seizure localization accuracy, but this has never been tested. Therefore, we evaluated the impact of parameter selection on seizure onset zone (SOZ) localization using automatically detected HFOs. We detected HFOs in intracranial EEG from twenty medically refractory epilepsy patients with seizure free surgical outcomes using an automated algorithm. For each patient, we assessed classification accuracy of channels inside/outside the SOZ using a wide range of detection parameters and identified the parameters associated with maximum classification accuracy. We found that only three out of twenty patients achieved maximal localization accuracy using conventional HFO detection parameters, and optimal parameter ranges varied significantly across patients. The parameters for amplitude threshold and root-mean-square window had the greatest impact on SOZ localization accuracy; minimum event duration and rejection of false positive events did not significantly affect the results. Using individualized optimal parameters led to substantial improvements in localization accuracy, particularly in reducing false positives from non-SOZ channels. We conclude that optimal HFO detection parameters are patient-specific, often differ from conventional parameters, and have a significant impact on SOZ localization. This suggests that individual variability should be considered when implementing automatic HFO detection as a tool for surgical planning.

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