Surgical skill directly affects surgical procedure outcomes; thus, effective training is needed to ensure satisfactory results. Many objective assessment metrics have been developed that provide the trainee with descriptive feedback about their performance however, these metrics often lack feedback on how to improve performance. The most effective training method is one that is intuitive, easy to understand, personalized, and provided in a timely manner. We propose a framework to enable user-adaptive training using near real-time detection of performance, based on intuitive styles of surgical movements, and design a haptic feedback framework to assist with correcting styles of movement. We evaluate the ability of three types of force feedback (spring, damping, and spring plus damping feedback), computed based on prior user positions to improve different stylistic behaviors of the user during kinematically constrained reaching movement tasks. The results indicate that five out of six styles studied here were improved using at least one of the three types of force feedback. Task performance metrics were compared in the presence of the three types of feedback. Task time was statistically significantly lower when applying spring feedback, compared to the other two types of feedback. Path straightness and targeting error were statistically significantly improved when using spring-damping feedback compared to the other two types of feedback. This study presents a groundwork for adaptive training in robotic surgery based on near real-time human-centric models of surgical behavior.

Objective and automatic evaluation of surgical skill is important for the design of surgical simulators used in surgical robotics training. Extensive research has been done to identify and evaluate a variety of evaluation metrics (e.g., path length, completion time); however, these metrics are only provided to the user after completion of the task, and may not fully use the underlying information in the movement data. This study proposes a method for automatic and objective evaluation of surgical expertise levels, in short time intervals, during task performance. We first compare three different automatic feature extraction methods including: (1) principle component analysis (PCA), (2) independent component analysis (ICA), and (3) linear discriminant analysis (LDA) on low-level position data, in their ability to distinguish among different expertise levels. We then study the performance of the best feature extraction method in different time intervals, for the purpose of finding the minimal time frame that accurately predicts user skill level. 14 subjects of different expertise levels were recruited to perform two simulated tasks on the da Vinci training simulator. The position of the subjects’ arm joints (shoulder, elbow and wrist) in the dominant hand, as well as the position of both hands, were recorded. Four classifiers (Naive Bayes, support vector machine, nearest neighbor, and Decision Tree) were used to identify the best feature extraction method. The results indicate that PCA in combination with support vector machine can classify expertise levels with an accuracy of 98% in time frames of 0.25 seconds.