Automatic Alignment of Fractured Femur: Integration of Robot and Optical Tracking System

This letter presents Robossis, a surgical robotic system for automated femur fracture alignment. Robossis is the integration of an optical tracking system with a 6-degree-of-freedom (6-DOF) 3-armed parallel robot that satisfies the clinical and mechanical design requirements for femur alignment surgery. In real-time, the optical tracking system obtains the spatial position of the distal and proximal parts of the fractured femur. Then, an auto-alignment algorithm uses this data to guide the robot to automatically and accurately align the bone fragments while overcoming the muscle payload surrounding the femur. A graphical user interface (GUI) provides a real-time visual guide for the surgeon to check the deviation from alignment while the robot is automatically bringing the bone into an aligned position. To demonstrate the capabilities of Robossis, laboratory and cadaver experiments are performed, showing that Robossis can successfully manipulate bone in 6 DOFs in space, achieving alignment with submillimeter accuracy.