  Purpose: In this paper, we present a novel approach to the automatic
evaluation of open surgery skills using depth cameras. This work is intended to
show that depth cameras achieve similar results to RGB cameras, which is the
common method in the automatic evaluation of open surgery skills. Moreover,
depth cameras offer advantages such as robustness to lighting variations,
camera positioning, simplified data compression, and enhanced privacy, making
them a promising alternative to RGB cameras.
  Methods: Experts and novice surgeons completed two simulators of open
suturing. We focused on hand and tool detection, and action segmentation in
suturing procedures. YOLOv8 was used for tool detection in RGB and depth
videos. Furthermore, UVAST and MSTCN++ were used for action segmentation. Our
study includes the collection and annotation of a dataset recorded with Azure
Kinect.
  Results: We demonstrated that using depth cameras in object detection and
action segmentation achieves comparable results to RGB cameras. Furthermore, we
analyzed 3D hand path length, revealing significant differences between experts
and novice surgeons, emphasizing the potential of depth cameras in capturing
surgical skills. We also investigated the influence of camera angles on
measurement accuracy, highlighting the advantages of 3D cameras in providing a
more accurate representation of hand movements.
  Conclusion: Our research contributes to advancing the field of surgical skill
assessment by leveraging depth cameras for more reliable and privacy
evaluations. The findings suggest that depth cameras can be valuable in
assessing surgical skills and provide a foundation for future research in this
area.
