Design and Evaluation of Visuo-Haptic Simulators for Skill Acquisition in Epidural Needle Insertion

Epidural analgesia is challenging, especially for novice anesthesiologists. Traditional approaches, relying on the 'see one, do one, teach one' paradigm, limit opportunities for extensive practice without patient risk. To address this challenge, a haptic-only simulator was previously developed and evaluated. In this study, we added immersive visualizations using Unity and Chai-3D platforms, creating two visuo-haptic simulators. We tested to see how these visual components would affect the simulator's face validity (realism) and content validity (perception of training effectiveness), and whether they would compromise performance. Twenty anesthesiologists of varying experience levels performed simulated epidural needle insertions using each simulator. We evaluated face and content validity through visual analog scale (VAS) questionnaires, and assessed user performance based on success rates and error measures. No statistically significant differences were found between the three simulators in user preference or performance metrics. The Unity-based simulator received slightly higher scores for visual realism, while the 'Chai-3D' simulator showed marginally better performance. Considering expert feedback and practical considerations such as ease of setup and seamless integration between the haptic and visual components, the 'Chai-3D' simulator emerged as the most suitable option for future use.