PURPOSE

The use of projector-based augmented reality (AR) in surgery may enable surgeons to directly view anatomical models and surgical data from the patient's surface (skin). It has the advantages of a consistent viewing focus on the patient, an extended field of view and augmented interaction. This paper presents an AR guidance mechanism with a projector-camera system to provide the surgeon with direct visual feedback for supervision of robotic needle insertion in radiofrequency (RF) ablation treatment.

METHODS

The registration of target organ models to specific positions on the patient body is performed using a surface-matching algorithm and point-based registration. An algorithm based on the extended Kalman filter and spatial transformation is used to intraoperatively compute the virtual needle's depth in the patient's body for AR display.

RESULTS

Experiments of this AR system on a mannequin were conducted to evaluate AR visualization and accuracy of virtual RF needle insertion. The average accuracy of 1.86 mm for virtual needle insertion met the clinical requirement of 2 mm or better. The feasibility of augmented interaction with a surgical robot using the proposed open AR interface with active visual feedback was demonstrated.

CONCLUSIONS

The experimental results demonstrate that this guidance system is effective in assisting a surgeon to perform a robot-assisted radiofrequency ablation procedure. The novelty of the work lies in establishing a navigational procedure for percutaneous surgical augmented intervention integrating a projection-based AR guidance and robotic implementation for surgical needle insertion.