MAGNETS: Magnetic Needle Tracking System

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MAGNETSMagnetic Needle Tracking System

• Vladimir Sibinovic¹, Bojana Petkovic², Goran
  Ðordevic¹
• ¹ University of Niš, Faculty of Electronic
  Engineering
• ² University of applied sciences, Erfurt

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Outline

• Introduction
• System
• Interferences
• Symmetry
• Statistical analysis of data
• Conclusion
• Further work
• References

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Introduction

• Part of project II44004, HUMANISAM, which is
  financed by Serbian Ministry of Science
• Percutaneous Vertebroplasty PVP
• Providing structural support for fractured and
  weaken vertebra
• Design and realization of a system for magnetic
  tracking of the needle during PVP

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System

• Based on Hall-effect sensors
• Senis GmbH Sentronis AD

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Magnet and needle

• Axial polarization
• Needle for PVP

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Interferences

• Are there interferences from the presence of
  human body?

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Symmetry

• Symmetry of data due to symmetry of the system
• Can be an advantage in further development
• Elimination of excess measurements
• Substitution of the sensors

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Symmetry graph
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Statistical analysis of data

• Statistics gives the best view of a large data
  set
• Mean, Standard deviation, Variance

Sensor Channel Mean Std Var
1 X 14.8107 0.4119 0.1696
1 Y -130.4028 0.3785 0.1433
1 Z 1055.9012 0.3547 0.1258
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Boxplot
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Conclusion

• We proven the hypothesis that the movement of the
  needle can be detected with Hall-effect
• The system is precise, but the actual precision
  is yet to be determine
• Data are consistent and repetitive
• System is immune to the interferences that can
  accrue during the procedure

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Further work

• Transformation of measured voltage values in to
  the position of the magnet, and with that the
  position of the needle
• Combination with X-ray fluoroscopy
• Determining the exact precision of the system

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References

• K. Gary, L. Ibanez and S. Aylward, D. Gobbi, M.
  B. Blake and K. Cleary, IGSTK An Open Source
  Software Toolkit for Image-Guided Surgery, IEEE
  Computer, April 2006.
• S. M. Samani, M. Yazdi, M. H. Bagheri ,
  Automatic Identification of Needles Entrance
  Point and Angle in Vertebroplasty, IEEE
  international Conference on Signal and Image
  Processing Applications, 2009.
• Senis GmbH, http//senis.ch/new-tranducer_data_she
  ets.html
• The MathWorks, Inc. MATLAB, www.mathworks.com
• Wikipedia, http//www.wikipedia.org/

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Questions ?
Thank you for your time