Depth cues in augmented reality for training of robot-assisted minimally invasive surgery

Training of robot-assisted minimally invasive surgery often includes supervised practice with a robotic surgical system. In this case, augmented reality can improve the communication between instructor and trainee, for example, by allowing the instructor to demonstrate skills with virtual surgical instruments that are shown to the trainee by means of augmented reality. However, virtual instruments are more difficult to handle than the real instruments---partly due to the lack of depth cues. In order to improve the usability of virtual surgical instruments, we compared five depth cues. Results showed both a preference for the artificial highlight cue and an aversion to transparency and depth of field. The highlight cue was therefore reviewed by experienced surgery instructors. These experts agreed that the highlight cue was beneficial and that the prototype could be used to some extent already and fully upon further development.