Design and Experimental Evaluation of a Leader-follower Robot-assisted System for Femur Fracture Surgery.

In the face of challenges encountered during femur fracture surgery, such as the high rates of malalignment and X-ray exposure to operating personnel, robot-assisted surgery has emerged as an alternative to conventional state-of-the-art surgical methods. This paper introduces the development of a leader-follower robot-assisted system for femur fracture surgery, called Robossis. Robossis comprises a 7-DOF haptic controller and a 6-DOF surgical robot. A control architecture is developed to address the kinematic mismatch and the motion transfer between the haptic controller and the Robossis surgical robot. A motion control pipeline is designed to address the motion transfer and evaluated through experimental testing. The analysis illustrates that the Robossis surgical robot can adhere to the desired trajectory from the haptic controller with an average translational error of 0.32 mm and a rotational error of 0.07°. Additionally, a haptic rendering pipeline is developed to resolve the kinematic mismatch by constraining the haptic controller's (user's hand) movement within the permissible joint limits of the Robossis surgical robot. Lastly, in a cadaveric lab test, the Robossis system was tested during a mock femur fracture surgery. The result shows that the Robossis system can provide an intuitive solution for surgeons to perform femur fracture surgery.