Experienced laparoscopic surgeons are automated to the "fulcrum effect": an ergonomic demonstration

The inversion of the normal laparoscopic image around the Y-axis has been shown to facilitate the rate of learning of a laparoscopic task in novice subjects. The aim of this study was to investigate the effect of Y-axis image inversion on the performance of experienced laparoscopic surgeons; this had not been previously investigated.

A total of 16 experienced surgeons,who had already carried out more than 50 operative laparoscopic procedures, and 16 novice participants, who had carried out no procedures, were required to make multiple defined incisions under laparoscopic laboratory conditions within ten 1-minute periods. Participants were randomly allocated to perform the task under either normal or Y-axis inverted imaging conditions (eight experienced surgeons and eight novices in each condition).

Y-axis inversion had a significant detrimental effect on the performance of the surgeons, whilst facilitating the performance of novices. The surgeons however, adapted to the inverted condition rapidly, showing a significant improvement in performance over the ten trials.

The Y-axis-inverted image has a detrimental effect on the performance of experienced surgeons, indicating that they have automated to the "fulcrum effect" of the abdominal wall on instrument manipulation. Y-axis-image inversion was found to facilitate significant learning trends, regardless of the participants' level of experience.