Toward an optimal performance index for neurosurgical robotʹs design

In the past years a large number of new surgical devices have been developed to improve the operation outcomes and reduce the patientʹs trauma. Nevertheless, the dexterity and accuracy required in positioning the surgical tools are often unreachable if the surgeons are not assisted by a suitable system. Since a medical robot works in an operating room, close to the patient and the medical staff, it has to satisfy much stricter requirements with respect to an industrial one. From a kinematic point of view, the robot must reach any target position in the patientʹs body, being as less invasive as possible for the surgeonʹs workspace. In order to meet such requirements, the right robot structure has to be chosen by means of the definition of suitable kinematic performance indices. In this paper some task-based indices based on the robot workspace and stiffness are presented and discussed. The indices will be used in a multiobjective optimization problem to evaluate best robot kinematic structure for a given neurosurgical task.