On the development of objective metrics for surgical skills evaluation based on tool motion

A key competency requirement in endovascular surgery is to optimally visualize and utilize pre-shaped catheters to navigate complex vascular anatomy, yet current performance assessment techniques are limited to grading scales based solely on observation. Since most endovascular procedures involve performing fine motor control tasks that require complex, dexterous movements, this paper explores the potential for a standardized, objective, and quantitative means of measuring technical competence based on analysis of the kinematics of endovascular tool tip motions. To accomplish this goal, we recorded catheter tip movement from twenty subjects performing fundamental endovascular tasks in an inanimate model and in a simulation environment with a virtual representation of the same inanimate model. Several motionbased performance measures that have been shown to reliably assess skill in other domains were computed and tested for correlation with data that were obtained from the global rating scale assessment tool. The metrics that quantified movement quality by assessing movement smoothness produced reliable correlations with the observation-based assessment metrics. These objective and quantitative metrics that capture movement quality could be incorporated into future training protocols to provide detailed feedback on trainee performance.