Actual developments of Navi-Robot, a navigator able to block itself in the correct position during orthopaedic surgical procedures

摘要

Abstract:- A self-balancing Navigation system able to turn itself into a robot, reaching the positions required to precisely guide a tool during a surgical procedure is under construction of the prototype. The instrument is, basically, a goniometric device, characterised by the presence of three arms, each bearing six degrees of freedom. Thus the instrument is able to measure the relative position between any of its extremes, two of the arms being only passive (measuring arms) the third being movable both actively and passively (the operating arm). Each arm has basically the configuration of a SCARA Robot, mounted on a vertical slide and counterbalanced by a weight mounted on a second vertical slide, the other extreme being either in the doctor’s hands or hooked to the patient. Each joint of the measuring arms presents an absolute encoder and a brake that allows locking the arm position in any configuration. The joints of the operating arm present a second brake allowing a motor to transmit motion to the joint. Therefore, when both brakes are lose, the arm is passive and can easily be moved, when the first brake is locked, the arm is rigid, while when the second brake is locked, the arms becomes a Robot. At the extremity of the measuring arms special connectors are present, that allow positioning the arm in a unique way with respect to a clamp nailed into the patient bone, while at the extreme of the operating arm special masks or pointers can be mounted either allowing using a saw or a drill in the proper plane or direction, or to detect bones profiles, leaving in any event to the doctor the real surgical act.