Background   Endoscopic retrograde cholangiopancreatography (ERCP) operators often face the difficulty in intubation of selective intrahepatic bile ducts. Repeated attempts at intubation greatly increase the occurrence of postoperative complications. In recent years, the use of augmented reality-assisted electromagnetic tracking for navigation during surgery has become an important auxiliary tool in minimally invasive surgery.

  Objective  To explore the positioning accuracy of using augmented reality-assisted electromagnetic navigation to guide ERCP bile duct intubation based on a three-dimensional (3D) printing model.

  Methods  Three-dimensional reconstruction of the abdominal CT data of a patient with choledocholithiasis accompanied by dilation of biliary tract was performed, and a 1 : 1.36 biliary tract model was generated by 3D printing. After the biliary model was embedded with the marked model as the “target” for navigation accuracy measurement, it was fixed in the human abdomen phantom. The abdomen phantom was pasted with marked models, then the phantom was scanned by CT and STL of the phantom was obtained by segmentation. An electromagnetic sensor was installed inside the channel of sphincterotomy to track its movement in the channel of the 3D printed model, and an augmented reality navigation platform was constructed using image overlay display. The image coordinates of markers outside the abdomen phantom through the preoperative CT scan and the magnetic field coordinates of markers during the operation were obtained to complete operative registration and augmented reality accuracy analysis.

  Results  The sphincterotomy was accurately guided into the left and right hepatic ducts under the AR-assisted electromagnetic navigation with navigation accuracy error of (0.949±0.033) mm, which could meet the requirement of clinical application.

  Conclusion  The model experiment confirmed augmented reality technology-assisted electromagnetic navigation can be used as an auxiliary means of ERCP bile duct intubation, which lays the foundation for further clinical application.