Measurement of electromagnetic tracking error in a navigated breast surgery setup

TitleMeasurement of electromagnetic tracking error in a navigated breast surgery setup
Publication TypeConference Paper
Year of Publication2016
AuthorsHarish, V., Baksh A., Ungi T., Lasso A., Baum Z. M. C., Gauvin G., C. Engel J., Rudan J., & Fichtinger G.
Conference NameSPIE Medical Imaging 2016
PublisherSPIE Medical Imaging
Conference LocationSan Diego, CA, United States, Feb. 29, 2016

The measurement of tracking error is crucial to ensure the safety and feasibility of electromagnetically tracked, image-guided procedures. Measurement should occur in a clinical environment because electromagnetic field distortion depends on positioning relative to the field generator and metal objects. However, we could not find an accessible and open-source system for calibration, error measurement, and visualization. We developed such a system and tested it in a navigated breast surgery setup.A pointer tool was designed for concurrent electromagnetic and optical tracking. Software modules were developed for automatic calibration of the measurement system, real-time error visualization, and analysis. The system was taken to an operating room to test for field distortion in a navigated breast surgery setup. Positional and rotational electromagnetic tracking errors were then calculated using optical tracking as a ground truth. Our system is quick to set up and can be rapidly deployed. The process from calibration to visualization also only takes a few minutes. Field distortion was measured in the presence of various surgical equipment. Positional and rotational error in a clean field was approximately 0.90 mm and 0.31°. The presence of a surgical table, an electrosurgical cautery, and anesthesia machine increased the error by up to a few tenths of a millimetre and tenth of a degree.In a navigated breast surgery setup, measurement and visualization of tracking error defines a safe working area in the presence of surgical equipment. Our system is available as an extension for the open-source 3D Slicer platform.

PerkWeb Citation KeyHarish2016a