Ergonomic evaluation of three new principles for mono-incision in laparoscopic surgery

Several instruments exist for performing a simple laparoscopic procedure through one trocar-incision. However, all of these instruments have well-known image-related disadvantages. In order to solve these problems three principles have been developed for which a new device was designed. The functionality of this device was evaluated with regard to four parameters: duration of task completion, number of errors, image-stability and preference by users. Although the differences between the three principles were small, the tests clearly showed that the problems surgeons experienced before have been significantly diminished by the new device. Time measurements showed a preference for principles 1 and 2 (1: manual zoom camera in combination with a standard grasping device; 2: laparoscope with an angle of 45 degrees in combination with a standard grasping device), the surgeons expressing preference for principle 2. Furthermore, the new trocar system is the first device for mono-incision in which two standard instruments (currently available on the market) are used simultaneously without enlarging the incision. Finally, each surgeon can work with the new device using the principle he/she is preferring.