Objective assessment of laparoscopic targeting skills using a Short-Time Power of Difference (STPOD) method

To ensure that the use of surgical training tools results in improvement of surgical skills, it is necessary to be able to measure and assess surgeons' skills. We established the Short-Time Power of Difference (STPOD) method as an evaluation tool for evaluating targeting technique. The STPOD method evaluates the distance from the actual movement of the forceps to the shortest linear path between two points in a short time period. We examined the effectiveness of the STPOD method as a new forceps kinematic analysis.

Six residents were categorized as novices and six urologists as experts. All participants performed box trainer training and LapPASS^® Simulator training. During the procedure, objective scores (time, distance, and STPOD) were recorded. STPOD (Power) evaluated motion smoothness and STPOD (Stop) evaluated the stop time of the forceps.

STPOD (Stop) on the right side of the experts was significantly lower than that of the novices in the box trainer. Furthermore, there were significant differences in the distances of left side and STPOD (Power) between the experts and the novices in the simulator. In the correlation of parameters between the box trainer and the simulator, time showed the strongest correlation, STPOD (Power) and distance showed a mild correlation.

We showed the construct validity of STPOD (Power) and STPOD (Stop) using both the box trainer and the simulator. This method is a good evaluation tool for assessing a physician's skill; however, there are much more complex motions that are performed in actual surgery. Future studies are needed to focus on evaluation in an environment closer to actual surgery and comparing with other existing methods.