Vector projection of biomagnetic fields

  • L. A. Bradshaw
  • A. Myers
  • W. O. Richards
  • W. Drake
  • J. P. Wikswo


Biomagnetic measurements are increasingly popular as functional imaging techniques for the non-invasive assessment of electrically active tissue. Although most currently available magnetometers utilise only one component of the vector magnetic field, some studies have suggested the possibility of obtaining additional information from recordings of the full magnetic field vector. Three projection techniques were applied to different biomagnetic signals for analysis of the three orthogonal components of the vector magnetic field. Vector magnetic fields obtained from fetal cardiac activity were projected into evenly spaced directions around a unit sphere. The vector magnetic field recorded from multiple intestinal current sources with independent temporal frequencies was then projected. Finally, an external reference signal from an invasive electrode was used to project the recorded vector magnetic fields due to gastric electrical activity. In each case, it was found that the information obtained by examination of the projected magnetic field vectors have superior clinical insight to that obtained by analysis of any single magnetic field component.


Magnetocardiogram Magnetogastrogram Bio-electromagnetism Gastrointestinal physiology 


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Copyright information

© FMBE 2005

Authors and Affiliations

  • L. A. Bradshaw
    • 1
    • 2
  • A. Myers
    • 2
  • W. O. Richards
    • 2
  • W. Drake
    • 3
  • J. P. Wikswo
    • 1
    • 4
    • 5
  1. 1.Department of Physics & AstronomyVanderbilt UniversityNashvilleUSA
  2. 2.Department of SurgeryVanderbilt UniversityNashvilleUSA
  3. 3.Division of Pediatric CardiologyVanderbilt UniversityNashvilleUSA
  4. 4.Department of Biomedical EngineeringVanderbilt UniversityNashvilleUSA
  5. 5.Department of Molecular Physiology & BiophysicsVanderbilt UniversityNashvilleUSA

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