讲座通知：Design of a Virtual Endolumenal Surgery Simulator (VESS) for Endoscopic Submucosal Dissection (ESD)
讲座题目：Design of a Virtual Endolumenal Surgery Simulator (VESS) for Endoscopic Submucosal Dissection (ESD)
INTRODUCTION: Colorectal cancer is one of the most common cancers in the United States. Endoscopic Submucosal Dissection (ESD) is an emerging minimally invasive technique that allows complete en-bloc resection and a much lower recurrence rate at long-term follow-ups. However, performing colorectal ESD is technically demanding since the colorectal wall is thin and constantly moving, and potentially higher rates of complications (e.g., bleeding and perforations), and there is lack of a sufficient number of expert instructors for ESD training in Western countries. One approach to reducing this gap is to design an ESD surgical simulator as part of a training curriculum.
OBJECTIVES: The aim of the study is to design a virtual endoluminal surgical simulator (VESS) with visual and haptic feedback along with assessment metrics based on a cognitive task analysis (CTA) approach. The simulator allows trainees to attain competence in a controlled environment with no risk to patients and can assess the trainees’ performance.Training tasks are built based on physics-based computational models of human anatomy with tumors.
METHODS: To design a virtual ESD simulator that will allow trainees to hone their ability to recognize and anticipate critical obstacles during the performance of ESD procedures, and enhance their decision-making skills, the results of a CTA are being integrated into the simulator as learning objectives and associated metrics. The main modules of the VR-based simulator forcolorectalESDas shown in Fi.g 1 involve (1) real-time rendering; (2) haptic interface; (3) physics-based simulation; and (4) performance recording and assessment metrics. The rendering engine allows surgical tasks to be performed in the three-dimensional virtual environment. Haptic feedback mechanisms allow users to physically feel the interaction forces. Physics-based simulation technologies are employed to enable the complicated simulation for performing virtual surgical tool-tissue interactions.The simulator can also collect learners’ performance data to offer feedback based on the built-in metrics.
RESULTS: Four training tasks involving marking, injection solution, circumferential cutting, and submucosal dissection as shown in Fig. 2 (the left is real surgery, while the right is virtual) are designed to practice skills with different surgical tools. The marking task aims to identify the lesion. The injection solution task minimizes the risk of bleeding and perforation to protect the muscularis. In the circumferential cutting task, the objective is initial incision of the lesion with the surgical tools. The objective of the dissection task is to remove the tumor from the connective tissue of the submucosa under the lesion.
CONCLUSIONS:This study presents a CTA-based approach to design a virtual ESD simulatorthat involves high-fidelity anatomical organ modeling, physics-based tool-tissue interactions, and performance metrics. The simulator enables realistic ESD tasks to provide a possibility for designing, validating and objectively evaluating the performance metrics in colorectal ESD training, and offers an opportunity to rise up the learning curve before application to patients.