New model for skills assessment and training progress in minimally invasive surgery

Background: With the spread of minimally invasive surgery and training in this field, development of metrics for skills assessment and training progress has become increasingly important. Our approach was to use the tracking of motion for the definition of objectives metrics. Methods: We have developed an inanimate model and tracked the 3D coordinates of the instrument tips with an ultrasound system. Besides already validated parameters (time, error time, and distance efficiency ratio) we examined the transit and the speed profile for their evidentiary power. Performances of experts (who have already performed >100 laparoscopic operations) and novices (<20 laparoscopic operations) were evaluated. Results: The standardized time, the error time as a precision indicator, and the transit profile parameter for spatial perception could significantly (p<0.05) distinguish between experts and novices. Furthermore, these parameters and the distance efficiency ratio improved significantly during a training course in laparoscopic surgery. Conclusion: Our model showed changes of the mentioned parameters with experience. According to our results, it can be used for skills assessment and as a training progress measurement system. We propose transit profile as an additional important parameter for assessment.