Improving hand-eye-coordination in laparoscopy using a virtual endoscope monitor

While laparoscopic procedures offer considerable advantages for the patient, they pose substantial challenges for the surgeon, whose hand-eye coordination is impaired. One reason for this is the surgeon's lost visual access to the surgical field, who is instead provided with an endoscopic image on a stationary monitor. In the present study, an optical see-through head-mounted display (OST-HMD) was used to display a virtual endoscope monitor. Unlike stationary monitors, this allows the endoscope image to be projected at arbitrary positions in the room.

The benefits of this approach were evaluated in a user study. N = 10 surgeons carried out a threading task in a pelvic trainer integrated in an operating room setup. Four positions of the endoscope image were compared: frontal view ( $0^{\circ }$ ), offset by ${60}^{\circ }$ to the left and right, and projected directly onto the surgical field.

The results show that for complex bimanual tasks, projecting the endoscope image onto the surgical field led to a halving of execution times in the study. In addition, the forces applied during threading were measured, but no significant effects of perspective were found. More experienced surgeons also reported significantly lower mental workload with the frontal view ( $0^{\circ }$ ) and the projection onto the surgical field compared to the other conditions.

This study provides first evidence that an OST-HMD could be a suitable way for flexibly displaying endoscopic images in laparoscopy and could help improve the surgeon's hand-eye coordination, while at the same time being easily integrated into the clinical environment.