Design of a box trainer for objective assessment of technical skills in single-port surgery

Laparoscopic single-port (SP) surgery uses only a single entry point for all instruments. The approach of SP has been applied in multiple laparoscopic disciplines owing to its improved cosmetic result. However, in SP surgery, instrument movements are further restricted, resulting in increased instrument collisions compared with standard multiport (MP) laparoscopy.

Our goal was to develop a trainer that can quantitatively measure task time, force and motion data during both MP and SP training to investigate the influence of instrument configuration on performance. Custom-made abdominal force sensors and accelerometers were integrated into a new training box that can be used in an SP and an MP configuration. This new box trainer measures forces, acceleration, and tilt angles during training of SP and MP laparoscopy. With the new trainer, 13 novices performed a tissue manipulation task to test whether significant differences exist between MP and SP in maximum abdominal force, maximum tissue manipulation force, maximum acceleration, and tilt angles of the handles.

The results show that the task time (SP-145s, standard deviation (SD) = 103 vs MP-61s SD = 16), maximum abdominal force (SP-8.4N, SD = 2.0 vs MP-left (L)-3.3N, SD = 0.8 and MP-right (R)-5.8N, SD = 2.1), tissue manipulation force (SP-10.4N, SD = 3.6 and MP-5.6N, SD = 1.3), maximum acceleration (MP-L-9m/s(2), SD = 5 vs SP-L-14m/s(2), SD = 7), and tilt angles of the left handle are significantly higher in SP.

This study shows that the new trainer can be used to find the most important differences in instrument and tissue handling, which is an important step toward the assessment of surgical skills needed for safe SP surgery depending on force and motion-based parameters.