Bimanual Coordination in Team-Based Precision Cutting

Student Researcher:
Betty Wang

Supervisor / Principle Investigator:
Dr. Bin Zheng

Additional Authors:
Fangshi Lu
Paola Sanchez
Davind Pinzon

MD Class of 2019


Background: Completing complex surgical tasks in minimally invasive surgery (MIS) often requires surgical assistants, utilizing multiple instruments. Currently, no guidelines exist on how to best execute complex surgical tasks. What is the best way to break down complex surgical tasks that require more than two hands? Bimanual coordination, which is described as using both hands to manipulate an object or performing a task, is often violated in MIS.

Hypothesis: Task time and error rate will increase when the surgeon gives up bimanual coordination, compared to preserving bimanual coordination in executing complex surgical tasks.

Subjects: 6 pairs of surgical novices (total 12 participants), one person as a surgeon and other as an assistant.

Task: Fundamentals of Laparoscopic Surgery precision cutting task

Apparatus: The simulator contains a 4x4 gauze, with a circle representing the surgical target. A rubber band is stretched across the circle, effectively disrupting direct access to the surgical target.

Procedure: Each pair performed the precision cutting task twice. In condition BC (bimanual coordination), the surgeon cut and retract the gauze using both hands, while the assistant handles the camera and retracts the rubber band to allow access to the surgical site. In condition SBC (sacrificing bimanual coordination), the surgeon has to withdraw the rubber band using one hand, while cutting the circle using the other, with the assistant holding the gauze taut to allow for cutting (and camera handling).

Analysis: Performance was evaluated based on completion time, accuracy, and other variables such as instrumental co-interference, and camera angles. Adjusted task time is calculated using a common scoring system.

Results: Adjusted task time for condition BC is 518.0 seconds, accuracy score is 26.8. For condition SBC, 642.9 seconds and 27.7.

Conclusion: There is no statistically significant difference in both adjusted task time and accuracy between the two conditions.