Accelerometer measurement of head movement during laparoscopic surgery as a tool to evaluate skill development of surgeons

Objective To detect and measure surgeons' head movement during laparoscopic simulator performance to determine whether expert surgeons have economy of motion in their head movement, including change of direction, compared with intermediate and novice surgeons. We investigated head movement as an objective tool for assessment of laparoscopic surgical skill and its potential use for assessing novice surgeons' progress on the learning curve. Design After obtaining institutional review board approval, medical students, urology residents, and attending staff surgeons from an academic institution were recruited. Participants were grouped by level of experience and performed tasks on the Electronic Data Generation for Evaluation laparoscopic simulator. Surgeons wore a commercially available wireless electroencephalogram monitor as a flexible, adjustable, and lightweight headband with 7 sensors - 2 forehead sensors, 2 ear sensors, and 3 reference sensors. The headband incorporates a 3-axis accelerometer enabling head movement quantification. A variance analysis was used to compare the average head movement acceleration data between each group. Setting Tulane University Medical Center, New Orleans, LA, an academic medical center and the principal teaching hospital for Tulane University School of Medicine. Participants A total of following 19 participants were recruited for the study and stratified by surgical experience into novice (n = 6), intermediate (n = 9), and expert (n = 4) laparoscopy groups: 6 medical students, 9 urology residents (postgraduate years 1 to5), and 4 attending urologists, respectively. Results Analysis of the average acceleration rate of head movement showed statistically significant differences among groups on both the vertical axis (p = 0.006) and horizontal axis (p = 0.018) in the laparoscopic suturing task. This demonstrated the ability to distinguish between experts and novice laparoscopic surgeons. The average acceleration among groups did not demonstrate statistical significance on the vertical axis (p = 0.078) and horizontal axis (p = 0.077) in the peg transfer task. This may be in response to the ease of the task. The analysis of the forward-backward axis or depth perception also showed no significant differences between groups. Conclusion Accelerometer-based motion analysis of head movement appears to be a useful tool to evaluate laparoscopic skill development of surgeons in terms of their economy of motion, and it could potentially be used for ergonomic assessment of training in the future, and progression on the learning curve.