A system, method, and article of manufacture for guiding an end effector to a target position within a person are provided. The method includes generating a plurality of digital images of an interior anatomy of the person when the person has a predetermined respiratory state. The method further includes indicating a skin entry position on at least one of the digital images. The method further includes indicating the target position on at least one of the digital images. The method further includes determining a trajectory path based on the skin entry position and the target position. Finally, the method includes moving the end effector along the trajectory path toward the target position when the person has substantially the predetermined respiratory state.
