ABSTRACT
Surgical robots are able to position the surgical tools closer to the “right spot” and deviate less from the “right trajectory”. The robot’s end-effectors can be much smaller and more dexterous than a human hand. They can record and filter out a surgeon’s natural hand tremor and rescale movement to increase precision and reduce the chance for error. Lastly, the robot could restrain the surgeon’s movement into undesired directions through haptic feedback. Researchers are formulating new ways to address motion and tissue resistance. For example, the surgical robot could synchronically move with a beating heart such that their relative speed is close to zero. Another possible improvement is the ability for the robot to automatically adapt to the dynamical tissue resistance over time as the sensitivity scale of these processes goes beyond human capabilities. Typically, robotic surgery can be classified as either (i) supervisory-controlled, (ii) telesurgical, or (iii) shared-controlled. The supervisory-controlled approach is the most automated of the three methods. The RoboDoc from Integrated Surgical Systems Inc. is an example of a supervisory-controlled system used in orthopedic surgeries. After the surgeon positions the RoboDoc’s bone-milling tool at the correct position inside the patient, the robot automatically cuts the bone to just the right size for the orthopedic implant. Prior to the surgical procedure, the surgeon needs to prepare the operation through the planning and registration phase. In the plan-ning phase, images of the patient’s body are used to determine the right surgical approach. Common imaging methods include compu-ter tomography (CT) scans, magnetic resonance imaging (MRI) scans, ultrasonography, fluoroscopy and X-ray scans. Next, in the registra-tion phase, the surgeon must locate the points on the patient’s body that correspond to the images created during the planning phase. These points are matched to a 3D model, which can be updated by images seen through cameras or other real-time imaging techniques during surgery. After the robot finds the best fit between the model and reality, the surgical procedure is performed. The telesurgical approach allows the surgical robot to be tele-operated, that is, operated from a distance by a human surgeon. In practice, the robot and the surgeon are only a couple of meters apart. Teleoperation is also possible across larger distances. However, problems such as time delays (i.e., telesurgical latencies) and the
available bandwidth (i.e., the amount of information that can be transferred per unit time) need to be considered. The telesurgical approach is used by the da Vinci Surgical System, which was invented by Philip S. Green and developed by Intuitive Surgical Inc. This system currently dominates the surgical robot market. Initially dubbed Mona (after Leonardo’s Mona Lisa), the system was re-christened the da Vinci Surgical Robot in 1999; according to Mr. Green “…in honour of the man who had invented the first robot.” Although it appears that da Vinci never invented or built a real robot, he made many drawings of various mechanisms.
