RESUMEN
This article presents a system for tracking, recording, and analysis of instrument and surgeon's arm motion in minimally invasive surgeries. The captured trajectories can be objectively analyzed for both ergonomic assessment and skills evaluation. The system consists of two special infrared (IR) markers that are used for 6 degrees of freedom (DOF) laparoscopic instrument tracking and a set of 3DOF IR markers attached to elbows and shoulders. A compact IR camera tracks and records the markers during a standardized training task (eg, suturing). The instrument markers were purposely designed to provide good tracking while minimizing their volume. The accuracy of the instrument markers was evaluated showing a root mean square error of 0.61 mm, 1.0 mm, and 2.4 mm at distances from the camera of 0.5 m, 0.68 m, and 1 m respectively. Furthermore, some sample trajectories were recorded during an in-trainer suturing task. The Results section presents the values of basic skills metrics computed from the acquired data.