Methods for end-effector coupling in robot assisted interventions

Robot assisted interventions often require coupling and decoupling of the robot to/from a specific tool. By using manual gripper changing systems these operations are facilitated, but the robot has to approach to and move away from the coupling position. Industrial applications are mostly based on movements which are teached-in, since the working environment is perfectly described (i.e. working cell). Especially in robot assisted surgery we are facing non fixed tools to which the robot has to be coupled (e.g. a holding device attached to a mobilised bone) and restricted working areas with special safety requirements. In this paper we present an automatic end-effector registration method and a semiautomatic coupling procedure exemplarily for robot assisted orthognathic surgery. By using means of an optical localisation system and force-/torque sensing, the coupling procedure is controlled by a multi-sensor data fusion approach. The developed methods can be adapted to any robot assisted intervention.