Design of Virtual Fixtures for Robotic Cholecystectomy.

BACKGROUND AND

OBJECTIVE

With the ongoing developments in robotic surgery, the associated adverse events need to be carefully evaluated. Virtual fixtures (VFs), a safety design feature against unintended motion during robotic surgery, have been proposed, but the methodology for designing VFs remains experimental. In this study, we propose a novel methodology for designing VFs for robotic cholecystectomy.

MATERIALS AND

METHODS

Laparoscopic cholecystectomy (LC) was performed in 24 patients with cholecystitis. Active working space (AWS), the distance between instrument heads (DBIH), motion speed of bilateral hands, and instrument heads were calculated and analyzed.

RESULTS

DBIH was 14.78 ± 6.94 cm. Diameter of right and left AWS was 15.81 ± 3.69 cm and 15.33 ± 1.52 cm, respectively. DBIH was found to significantly correlate with the surgeon's experience. Bilateral AWS was found to be significantly associated with body circumference at Murphy's point level. However, no association was observed between bilateral AWS and surgeon's experience.

CONCLUSIONS

A novel methodology to build VFs for designing VFs for robotic cholecystectomy is established. Surgeon's experience appears to play an important role in determining the DBIH during robotic laparoscopic cholecystectomy, but does not affect bilateral AWS.