Real-time simulation of electrocautery procedure using meshfree methods in laparoscopic cholecystectomy

摘要

Virtual reality (VR) medical simulators with visual and haptic feedback provide an efficient and cost-effective alternative without any risk to the traditional training approaches. Electrocautery is one of the essential training tasks in laparoscopic cholecystectomy. In order to achieve a high fidelity with visual realism in electrocautery simulation, we propose a physical-based solution to handle the soft tissue deformation and topology change which occurs due to the heat generated by electro-hook. The whole computation is built on discrete particles. For cholecystectomy simulation, the first task is to remove the fat tissue which wraps the cystic artery and duct with electro-hook. We use a meshfree method to handle the fat tissue deformation which based on continuum elasticity equations. And a meshfree dissection model is also introduced to handle the thermal transmission when electro-hook touches the fat surface. Both models are implemented on GPU to achieve real-time performance. The visual performance and computational cost of the proposed method are properly evaluated and compared with other popularly used approaches. From the experimental results, our electrocautery simulation can achieve real-time performance with high degree of realism and fidelity. This technique has also been adopted in our developed VR-based laparoscopic surgery simulator, which has been tested and verified by laparoscopic surgeons through a pilot study. Surgeons believed that the visual performance is realistic and helpful to enhance laparoscopic electrocautery skills. Our system exhibits the potentials to improve the surgical skills of medical practitioners during their training sessions and effectively shorten their learning curve.