The first robotic surgery took place in 1985 when the PUMA 560 was used in a stereotaxic operation in which computed tomography (or x-ray) was used intraoperatively to guide a robot as it inserted a needle into the brain for biopsy. In the late 1980s and early 1990s, robotic systems began to be used for laparoscopic surgery, in which a flexible optical instrument was inserted into the body and used to guide surgeons through hard-to-reach areas, from the pelvis to the chest cavity.