Uncertainty in electromagnetic position tracking


Prof. Gabor Fichtinger (gabor@cs.queensu.ca)

Hossein Sadjadi, MSc, Research Assistant (h.sadjadi@queensu.ca)



Robust and accurate tracking the position and orientation of surgical tools and targets poses a major challenge in computer-assisted surgery. Electromagnetic (EM) tracking devices have been introduced to tackle this challenge, and are widely used for various applications. However, tracking uncertainty has led to localization error, and restricted the application of EM trackers, especially with the presence of metallic objects.



  • Review previous studies on EM tracking accuracy and precision measurements
  • Identify the main sources of measurement error and uncertainty
  • Design and perform experiments to quantify the tracking uncertainty (due to distance from the transmitter, field distortion, etc.)
  • Implement an algorithm (preferably in MATLAB) to collect and analyze sensory information, and compare with ground truth (optical tracker, etc.)
  • Report the reliability, accuracy, and precision of the EM tracker
  • Contribute to peer reviewed publication


  • Implement a sensor fusion technique to reduce measurement error (Kalman, or particle filter)
  • Investigate the application of a simultaneous localization and mapping (SLAM) technique for robust navigation of surgical instruments



  • Gaining knowledge in position tracking, localization and coordinate transformation
  • Understanding the principles of measurement uncertainty as well as sensor performance measures
  • Learning MATLAB to handle signal processing tasks (data acquisition, filtering, and analysis)
  • Collaboration with a multidisciplinary group of biomedical researchers and software developers 



  • Understanding the fundamentals of computer-assisted surgery
  • Interest in performing experiments, data acquisition, and analysis
  • MATLAB programming



Project type: 

Undergraduate project