Detection and elimination of signal errors due to unintentional movements in biomedical magnetic induction tomography spectroscopy (MITS)

Research output: Contribution to journalArticleResearchpeer-review

Abstract

In biomedical MITS, slight unintentional movements of the patient during measurement can contaminate the aimed images to a great extent. This study deals with measurement optimization in biomedical MITS through the detection of these unpredictable movements during measurement and the elimination of the resulting movement artefacts in the images to be reconstructed after measurement. The proposed detection and elimination (D&E) methodology requires marking the surface of the object under investigation with specific electromagnetically perturbing markers during multi-frame measurements. In addition to the active marker concept already published, a new much simpler passive marker concept is presented. Besides the biological signal caused by the object, the markers will perturb the primary magnetic field inducing their own signals. The markers' signals will be used for the detection of any unwanted object movements and the signal frames corrupted thereby. The corrupted signal frames will be then excluded from image reconstruction in order to prevent any movement artefacts from being imaged with the object. In order to assess the feasibility of the developed D&E technique, different experiments followed by image reconstruction and quantitative analysis were performed. Hereof, target movements were provoked during multifrequency, multiframe measurements in the β-dispersion frequency range on a saline phantom of physiological conductivity. The phantom was marked during measurement with either a small single-turn coil, an active marker, or a small soft-ferrite plate, a passive marker. After measurement, the erroneous phantom signals were corrected according to the suggested D&E strategy, and images of the phantom before and after correction were reconstructed. The corrected signals and images were then compared to the erroneous ones on the one hand, and to other true ones gained from reference measurements wherein no target movements were provoked on the other hand. The obtained qualitative and quantitative measurement and image reconstruction results showed that the erroneous phantom signals could be accurately corrected, and the movement artefacts could be totally eliminated, verifying the applicability of the novel D&E technique in measurement optimization in biomedical MITS and supporting the proposed aspects.

Original languageEnglish
Pages (from-to)163-175
Number of pages13
JournalJournal of Electrical Bioimpedance
Volume9
Issue number1
DOIs
Publication statusPublished - 28 Dec 2018

Fingerprint

Computer-Assisted Image Processing
Electromagnetic induction
Artifacts
Tomography
Spectrum Analysis
Spectroscopy
Magnetic Fields
Image reconstruction
Ferrite
Magnetic fields

Keywords

  • Active marker
  • Detection and elimination
  • Imaging
  • Magnetic induction tomography spectroscopy
  • Movement artefacts
  • Movement errors
  • Passive marker

ASJC Scopus subject areas

  • Biophysics
  • Biomedical Engineering

Fields of Expertise

  • Human- & Biotechnology

Cite this

Detection and elimination of signal errors due to unintentional movements in biomedical magnetic induction tomography spectroscopy (MITS). / Issa, S.; Scharfetter, H.

In: Journal of Electrical Bioimpedance, Vol. 9, No. 1, 28.12.2018, p. 163-175.

Research output: Contribution to journalArticleResearchpeer-review

@article{ed02b42a29b44c23983bd068ed1c0076,
title = "Detection and elimination of signal errors due to unintentional movements in biomedical magnetic induction tomography spectroscopy (MITS)",
abstract = "In biomedical MITS, slight unintentional movements of the patient during measurement can contaminate the aimed images to a great extent. This study deals with measurement optimization in biomedical MITS through the detection of these unpredictable movements during measurement and the elimination of the resulting movement artefacts in the images to be reconstructed after measurement. The proposed detection and elimination (D&E) methodology requires marking the surface of the object under investigation with specific electromagnetically perturbing markers during multi-frame measurements. In addition to the active marker concept already published, a new much simpler passive marker concept is presented. Besides the biological signal caused by the object, the markers will perturb the primary magnetic field inducing their own signals. The markers' signals will be used for the detection of any unwanted object movements and the signal frames corrupted thereby. The corrupted signal frames will be then excluded from image reconstruction in order to prevent any movement artefacts from being imaged with the object. In order to assess the feasibility of the developed D&E technique, different experiments followed by image reconstruction and quantitative analysis were performed. Hereof, target movements were provoked during multifrequency, multiframe measurements in the β-dispersion frequency range on a saline phantom of physiological conductivity. The phantom was marked during measurement with either a small single-turn coil, an active marker, or a small soft-ferrite plate, a passive marker. After measurement, the erroneous phantom signals were corrected according to the suggested D&E strategy, and images of the phantom before and after correction were reconstructed. The corrected signals and images were then compared to the erroneous ones on the one hand, and to other true ones gained from reference measurements wherein no target movements were provoked on the other hand. The obtained qualitative and quantitative measurement and image reconstruction results showed that the erroneous phantom signals could be accurately corrected, and the movement artefacts could be totally eliminated, verifying the applicability of the novel D&E technique in measurement optimization in biomedical MITS and supporting the proposed aspects.",
keywords = "Active marker, Detection and elimination, Imaging, Magnetic induction tomography spectroscopy, Movement artefacts, Movement errors, Passive marker",
author = "S. Issa and H. Scharfetter",
year = "2018",
month = "12",
day = "28",
doi = "10.2478/joeb-2018-0021",
language = "English",
volume = "9",
pages = "163--175",
journal = "Journal of Electrical Bioimpedance",
issn = "1891-5469",
publisher = "Oslo Bioimpedance Group, Department of Physics, University of Oslo",
number = "1",

}

TY - JOUR

T1 - Detection and elimination of signal errors due to unintentional movements in biomedical magnetic induction tomography spectroscopy (MITS)

AU - Issa, S.

AU - Scharfetter, H.

PY - 2018/12/28

Y1 - 2018/12/28

N2 - In biomedical MITS, slight unintentional movements of the patient during measurement can contaminate the aimed images to a great extent. This study deals with measurement optimization in biomedical MITS through the detection of these unpredictable movements during measurement and the elimination of the resulting movement artefacts in the images to be reconstructed after measurement. The proposed detection and elimination (D&E) methodology requires marking the surface of the object under investigation with specific electromagnetically perturbing markers during multi-frame measurements. In addition to the active marker concept already published, a new much simpler passive marker concept is presented. Besides the biological signal caused by the object, the markers will perturb the primary magnetic field inducing their own signals. The markers' signals will be used for the detection of any unwanted object movements and the signal frames corrupted thereby. The corrupted signal frames will be then excluded from image reconstruction in order to prevent any movement artefacts from being imaged with the object. In order to assess the feasibility of the developed D&E technique, different experiments followed by image reconstruction and quantitative analysis were performed. Hereof, target movements were provoked during multifrequency, multiframe measurements in the β-dispersion frequency range on a saline phantom of physiological conductivity. The phantom was marked during measurement with either a small single-turn coil, an active marker, or a small soft-ferrite plate, a passive marker. After measurement, the erroneous phantom signals were corrected according to the suggested D&E strategy, and images of the phantom before and after correction were reconstructed. The corrected signals and images were then compared to the erroneous ones on the one hand, and to other true ones gained from reference measurements wherein no target movements were provoked on the other hand. The obtained qualitative and quantitative measurement and image reconstruction results showed that the erroneous phantom signals could be accurately corrected, and the movement artefacts could be totally eliminated, verifying the applicability of the novel D&E technique in measurement optimization in biomedical MITS and supporting the proposed aspects.

AB - In biomedical MITS, slight unintentional movements of the patient during measurement can contaminate the aimed images to a great extent. This study deals with measurement optimization in biomedical MITS through the detection of these unpredictable movements during measurement and the elimination of the resulting movement artefacts in the images to be reconstructed after measurement. The proposed detection and elimination (D&E) methodology requires marking the surface of the object under investigation with specific electromagnetically perturbing markers during multi-frame measurements. In addition to the active marker concept already published, a new much simpler passive marker concept is presented. Besides the biological signal caused by the object, the markers will perturb the primary magnetic field inducing their own signals. The markers' signals will be used for the detection of any unwanted object movements and the signal frames corrupted thereby. The corrupted signal frames will be then excluded from image reconstruction in order to prevent any movement artefacts from being imaged with the object. In order to assess the feasibility of the developed D&E technique, different experiments followed by image reconstruction and quantitative analysis were performed. Hereof, target movements were provoked during multifrequency, multiframe measurements in the β-dispersion frequency range on a saline phantom of physiological conductivity. The phantom was marked during measurement with either a small single-turn coil, an active marker, or a small soft-ferrite plate, a passive marker. After measurement, the erroneous phantom signals were corrected according to the suggested D&E strategy, and images of the phantom before and after correction were reconstructed. The corrected signals and images were then compared to the erroneous ones on the one hand, and to other true ones gained from reference measurements wherein no target movements were provoked on the other hand. The obtained qualitative and quantitative measurement and image reconstruction results showed that the erroneous phantom signals could be accurately corrected, and the movement artefacts could be totally eliminated, verifying the applicability of the novel D&E technique in measurement optimization in biomedical MITS and supporting the proposed aspects.

KW - Active marker

KW - Detection and elimination

KW - Imaging

KW - Magnetic induction tomography spectroscopy

KW - Movement artefacts

KW - Movement errors

KW - Passive marker

UR - http://www.scopus.com/inward/record.url?scp=85068989399&partnerID=8YFLogxK

U2 - 10.2478/joeb-2018-0021

DO - 10.2478/joeb-2018-0021

M3 - Article

VL - 9

SP - 163

EP - 175

JO - Journal of Electrical Bioimpedance

JF - Journal of Electrical Bioimpedance

SN - 1891-5469

IS - 1

ER -