Electromagnetic tracking of endoscopic ultrasound probe for pancreas examination: accuracy assessment under realistic medical conditions

Pancreatic cancer stands as the 3(rd)cause of death by cancer in 2021 and may become 2(nd) in a decade. In this context, early tumour diagnosis is primordial but unfortunately 3D medical imaging are not sensitive enough while Endoscopic ultrasound (EUS) allows early diagnosis. However it is not widely available due to its difficulty to master. We focus on developing a guidance system for low EUS expertise endoscopists . This would be enabled by providing a computer-assisted rendered scene showing patient's 3D model with a real-time representation of the registered EUS probe. The corresponding accuracy is largely relying on the efficient registration of the patient-specific model to the real patient pose during EUS examination. For that purpose, we developed an electromagnetic tracking system attached to an EUS probe. We detail the used registration algorithm and our original experimental method for accuracy measurement based on Cone Beam Computed Tomography. We demonstrate an accuracy in position and angle of respec-tively 10.4 +/- 4.0 mm and 8.7 degrees +/- 4.1 degrees in pre-clinical conditions. We also demonstrate that efficient navigation can be proposed to clinicians during EUS even in complex and realistic anatomy of a swine model. This work is paving the way to a guided EUS navigation system for pancreas examination.