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Updated: Jun 1, 2026
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Electromagnetic Navigation Transthoracic Nodule Localization for Minimally Invasive Thoracic Surgery
Published on: May 4, 2022
Real-time marker-free patient registration for electromagnetic navigated bronchoscopy: a phantom study
Daisuke Deguchi1, Marco Feuerstein, Takayuki Kitasaka
1Graduate School of Information Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya-shi, Aichi, 464-8601, Japan. ddeguchi@is.nagoya-u.ac.jp
Summary
A novel electromagnetic tracking method enables marker-free CT-to-patient registration for bronchoscopy guidance. This system achieves accurate real-time tracking, improving the safety and feasibility of image-guided lung biopsies.
Area of Science:
- Medical imaging and image-guided interventions
- Medical robotics and computer-assisted surgery
- Pulmonary medicine and interventional pulmonology
Background:
- Safe and smooth bronchoscopy is crucial for procedures like transbronchial lung biopsy (TBLB).
- Current bronchoscopic guidance systems often rely on electromagnetic tracking (EMT) for real-time bronchoscope tip localization.
- Existing registration methods require manual identification of patient landmarks or fiducial markers, introducing potential inaccuracies and procedural delays.
Purpose of the Study:
- To develop a marker-free CT-to-patient registration method for bronchoscopic guidance systems.
- To enable accurate real-time tracking of the bronchoscope tip using EMT without manual landmark identification.
- To enhance the safety and efficiency of image-guided procedures such as TBLB.
Main Methods:
- Developed a guidance system capable of real-time bronchoscope tip tracking via EMT.
- Proposed a novel registration method that estimates the transformation matrix between the patient and pre-acquired CT images without using fiducial markers or natural landmarks.
- The method computes correspondences between EMT sensor outputs and CT-derived airway structures, incorporating a stable airway branch selection mechanism to handle bifurcations and improve robustness.
Main Results:
- The proposed marker-free registration method achieved an accuracy of 2.0-3.0 mm without simulated breathing motion.
- With simulated breathing motion, the accuracy ranged from 2.5-3.5 mm, demonstrating robustness to respiratory artifacts.
- The system successfully tracked the bronchoscope camera in real time throughout the experiments.
Conclusions:
- A novel CT-to-patient registration method using EMT position sensing without fiducial markers or natural landmarks has been successfully developed.
- This marker-free registration approach facilitates feasible endoscopic-guided biopsies of lung lesions.
- The developed guidance system enhances the precision and safety of interventional pulmonology procedures.
