A 3-Armed 6-DOF Parallel Robot for Femur Fracture Reduction: Trajectory and Force Testing ^∗

Femur fractures are prevalent in the general population and require complex surgical intervention. A significant amount of time and effort is spent in restoring the alignment of femur fractures, which is called the reduction step. This particular step would benefit greatly from a robot-Assisted mechanism, where the majority of increased stress in the operating room occurs. To address this issue, we propose a Wide-Open 3-Armed parallel robot, entitled Robossis, that facilitates femur fracture reduction. Robossis system aims to improve patient outcomes by eliminating malalignment, reducing radiation exposure from X-rays during surgery, and decreasing the likelihood of follow-up operations. Experimental position testing in this study demonstrates that Robossis can reach the boundary points in the workspace with submillimeter accuracy. The force testing shows that Robossis can provide the required traction forces, up to 432 N, to align femur fractures. Furthermore, a femur fracture alignment test demonstrates Robossis ability to align the femur model fragments. These results establish the potential ability of Robossis to successfully align and reduce femur fractures in a clinical setting.