Robot-assisted RF ablation with interactive planning and mixed reality guidance

Radiofrequency (RF) ablation delivered through interventional procedure is a good alternative to hepatic resection or liver transplant for treatment of liver tumor. However, inefficient RF needle navigation and limited thermal ablation region challenge surgeons' manipulations. This paper presents robot-assisted RF ablation system for liver tumor treatment with interactive planning and mixed reality guidance. Interactive planning involves ablation model planning and surgeon's supervisory feedback via projector-based augmented reality (AR). The preoperatively defined surgical planning data is visualized directly on the patient body through the AR display, supplying information of insertion points, ablation points as well as preplanned trajectories, before execution by robot. The needle's spatial insertion is intraoperatively navigated by stereoscopic tracking and simulated in a model based virtual environment comprising anatomic and RF needle models. The robotic execution benefited from improved accuracy on needle's tip tracking and model based simulation. Ex vivo model and in vivo animal studies were conducted to validate and assess the performance of proposed mechanism. This solution is promising in overcoming current technological limitations and practical constraints of precise transcutaneous ablation therapy.