Viewpoint matters: objective performance metrics for surgeon endoscope control during robot-assisted surgery

Abstract

Background: Effective visualization of the operative field is vital to surgical safety and education. However, additional metrics for visualization are needed to complement other common measures of surgeon proficiency, such as time or errors. Unlike other surgical modalities, robot-assisted minimally invasive surgery (RAMIS) enables data-driven feedback to trainees through measurement of camera adjustments. The purpose of this study was to validate and quantify the importance of novel camera metrics during RAMIS.

Methods: New (n = 18), intermediate (n = 8), and experienced (n = 13) surgeons completed 25 virtual reality simulation exercises on the da Vinci Surgical System. Three camera metrics were computed for all exercises and compared to conventional efficiency measures.

Results: Both camera metrics and efficiency metrics showed construct validity (p < 0.05) across most exercises (camera movement frequency 23/25, camera movement duration 22/25, camera movement interval 19/25, overall score 24/25, completion time 25/25). Camera metrics differentiated new and experienced surgeons across all tasks as well as efficiency metrics. Finally, camera metrics significantly (p < 0.05) correlated with completion time (camera movement frequency 21/25, camera movement duration 21/25, camera movement interval 20/25) and overall score (camera movement frequency 20/25, camera movement duration 19/25, camera movement interval 20/25) for most exercises.

Conclusions: We demonstrate construct validity of novel camera metrics and correlation between camera metrics and efficiency metrics across many simulation exercises. We believe camera metrics could be used to improve RAMIS proficiency-based curricula.

Keywords: Endoscope control; Performance metrics; Proficiency; Robot-assisted surgery; Surgeon training; Visualization.

Fig. 1

Construct validity of conventional metrics and camera metrics. A Overall score, B completion time, C camera movement frequency (CFrq), D camera movement duration (CDur), and E camera movement interval (CInt). Horizontal bars indicate significant differences between surgeon groups (p < 0.05)

Fig. 2

Difference between novice and expert surgeons mean normalized metrics across all exercises (ordered by magnitude). Gray bars correspond to viewpoint metrics. Black bars correspond to conventional performance metrics. Error bars represent +1 SD. Top brackets indicate significant differences between metrics (p < 0.05)