Objective metrics for the evaluation of simple surgical skills in real and virtual domains

Surgical skills are traditionally assessed through subjective evaluation with experienced surgeons observing and rating trainee activity. However, this process can be expensive, particularly in terms of the time required of expert surgeons. Subjective assessment may also suffer from problems of intersubject variation in the application of evaluation criteria. Computer-based training, in particular systems combining virtual reality interfaces with haptic displays, offers a means of providing both automated and objective assessment of performance, In this paper we propose that, prior to the development of such systems, there is a need to determine measures that can adequately differentiate levels of performance. The paper therefore discusses the evaluation of surgical technique using objective metrics. Two main questions are addressed. How can surgical technique be assessed? What metrics prove useful in defining and modifying surgical skills and techniques?