Quantifying mental workloads of surgeons performing natural orifice transluminal endoscopic surgery (NOTES) procedures

Abstract

During natural orifice transluminal endoscopic surgery (NOTES), surgeons often have difficulties orienting the surgical view and manipulating instruments accurately, which increases their level of mental and physical fatigue. This study quantified mental workload by measuring the spared mental resources of surgeons performing NOTES training tasks. Assessment of mental workload was conducted in both a benchtop and a hybrid animal model. Using the benchtop model, surgeons were required to pass a ring as many times as possible in 6 min. Using the hybrid model, surgeons were required to dissect the gallbladder. While performing those primary tasks, the surgeon was required to identify true visual signals among many false signals displayed on an adjacent monitor. They were asked to repeat the trials using laparoscopy. The surgeons' performance on the primary and secondary tasks using the NOTES and laparoscopic approaches were recorded and compared. The nine surgeons who completed the trials in the benchtop model successfully transferred 13 ± 4 rings between targets using laparoscopy compared with a mean of 1.2 ± 1.0 rings transferred using NOTES (P < 0.001). The surgeons detected visual signals at a 74% rate using laparoscopy, which was significantly higher than the 54% detection rate with the NOTES procedure (P = 0.005). Using the hybrid model, 10 surgeons achieved a 55% accuracy rate performing the laparoscopic task. This was found to be significantly higher (P = 0.006) than when the task was performed using the NOTES platform (39%). The results showed that performance of a task using the NOTES platform increases surgeons' mental workload. Because difficulty performing NOTES is associated with flexible endoscopy, the authors expect that new operating systems providing stable platforms will help to decrease the mental workload of surgeons and enhance eye-hand coordination in performing NOTES.