Can surgical performance for varying experience be measured from hand motions?
This study evaluates if hand movements, tracked using digital video, can quantify in-context surgical performance. Participants of varied experience completed simple interrupted suturing and running subcuticular suturing tasks. Marker-less motion tracking software traced the two-dimensional position of a region of the hand for every video frame. Four expert observers rated 219 short video clips of participants performing the task from 0 to 10 along the following visual analog scales: fluidity of motion, motion economy, tissue handling, and coordination. Expert ratings of attending surgeon hand motions (mean=7.5, sd=1.3) were significantly greater (p<0.05) than medical students (mean=5.0, sd=1.9) and junior residents (mcan=6.4, sd= 1.5) for all rating scales. Significant differences (p<0.02) in mean path length per cycle were also observed both between medical students (803 mm, sd=374) and senior residents (491 mm, sd=216), and attendings (424 mm, sd=250) and junior residents (609 mm, sd=187). These results suggest that substantial gains in performance are attained after the second year of residency and that hand kinematics can predict differences in expert ratings for simulated suturing tasks commensurate with experience - a necessary step to develop valid and automatic on-demand feedback tools.
