Shared-control Robotic Surgery Systems

Shared-control robotic systems aid surgeons during surgery, but the human does most of the work. Unlike the other robotic systems, the surgeons must operate the surgical instruments themselves. The robotic system monitors the surgeon's performance and provides stability and support through active constraint.

Robotic surgery system
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A nurse prepares a robotic surgery system for heart surgery.


Active constraint is a concept that relies on defining regions on a patient as one of four possibilities: safe, close, boundary or forbidden. Surgeons define safe regions as the main focus of a surgery. For example, in orthopedic surgery, the safe region might be a specific site on the patient's hip. Safe regions don't border soft tissues.

In orthopedic surgery, a close region is one that borders soft tissue. Since orthopedic surgical tools can do a lot of damage to soft tissue, the robot constrains the area the surgeon can operate within. It does this by providing haptic responses, also known as force feedback. As the surgeon approaches the soft tissue, the robot pushes back against the surgeon's hand.

As the surgeon gets closer to soft tissue, the instrument enters the boundary region. At this point, the robot will offer more resistance, indicating the surgeon should move away from that area. If the surgeon continues cutting toward the soft tissue, the robot locks into place. Anything from that point on is the forbidden region.

Robotic surgery system
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Robotic surgeons can be intimidating -- they don't have the best bedside manner.


Like the other robots we've looked at, shared-control system robots don't automatically know the difference between a safe region versus a forbidden region. The surgeons must first go through the planning, registration and navigation phases with a patient. Only after inputting that information into the robot's system can the robot offer guidance.

­Abby Somebody
One potential future application of shared-control systems is neurosurgery. In a 2005 volume of Neurosurgery, doctors suggest a robotic system for brain surgery. The robot would have a single arm with multiple pivot points. The surgeon could rest his or her elbow on the robot's arm. The robot arm would also steady the surgical instrument. While the surgeon controls the motion of the instrument, the robot arm provides tremor control, stabilizing each movement [source: Nathoo, Narenda et al.].


Out of the three kinds of robot surgical systems, the telesurgical approach has received the most attention. The success of the da Vinci Surgical System caught the attention of doctors and the media alike. We may see more examples of shared-control and supervisory-controlled systems in the future.

While surgical robots offer some advantages over the human hand, we are still a long way from the day when autonomous robots will operate on people without human interaction. But, with advances in computer power and artificial intelligence, it could be that in this century scientists will design a robot that can locate abnormalities in the human body, analyze them and operate to correct those abnormalities without any human guidance.

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