Bone-mounted miniature robot for surgical procedures: Concept and clinical applications

This paper presents a new approach to robot-assisted spine and trauma surgery in which a miniature robot is directly mounted on the patient´s bony structure near the surgical site. The robot is designed to operate in a semiactive mode to precisely position and orient a drill or a needle in various surgical procedures. Since the robot forms a single rigid body with the anatomy, there is no need for immobilization or motion tracking, which greatly enhances and simplifies the robot´s registration to the target anatomy. To demonstrate this concept, we developed the MiniAture Robot for Surgical procedures (MARS), a cylindrical 5×7 cm³, 200-g, six-degree-of-freedom parallel manipulator. We are currently developing two clinical applications to demonstrate the concept: 1) surgical tools guiding for spinal pedicle screws placement; and 2) drill guiding for distal locking screws in intramedullary nailing. In both cases, a tool guide attached to the robot is positioned at a planned location with a few intraoperative fluoroscopic X-ray images. Preliminary in-vitro experiments demonstrate the feasibility of this concept.