Cooperative Robotic System to Support Surgical Interventions

Currently computer assisted surgery is dominated by use of navigation systems. These systems track the position of surgical instruments by the use of a 3D digitizing system and insert a corresponding symbol in the pre-operative image on the computer screen. First originating from applications in neurosurgery, Ear-Nose-Throat (ENT) and spinal surgery, such systems have found wide acceptance in most bone-related surgical interventions. However, surgical instruments are still guided manually. Unintentional deviations caused, for example, by hand tremor, slipping or inhomogeneous bone structure can occur. Robotic systems for computer assisted surgery have gained a lot of interest and are investigated by several research groups, but they are rarely found in clinical practice. The concept of commercial systems like Robodoc (Kazanzides, 1999) and CASPAR (Grueneis, 1999), which have been introduced for milling the stem cavity in total hip replacement surgery, has turned out to be not convincing. Many of those have been removed from the OR. There are other robotic solutions for surgery, including tele-manipulator systems like the daVinci system from Intuitive Surgical Inc., and robots for endoscope guidance in abdominal surgery, like the AESOP system (developed by Computer Motion, Inc.) or the EndoAssist from Armstrong Healthcare (Davies, 2000). However, the operational mode of these systems is not based on computer assisted pre-operative planning and intraoperative registration, and they will not be discussed in this paper. The interaction between surgeon and robotic system is a very important issue when thinking about its introduction within surgical interventions. Autonomous systems have lost acceptance in the surgical community because the surgeon wants to be in charge of the operation instead of acting only as an observer. In such scenario, the human experience, intuition, capability of react in front of unexpected situations is lost. An alternative solution is to provide a cooperative system where benefits of both can be derived. Some work has been done in relation to haptic interface for direct cooperation between surgeon and robot. Robotic systems like the JHU Steady Hand Robot from the Johns Hopkins University (Bettini, 2004) and the Hands-On Robot, also known as Acrobot (Davies, 2004), use active constraints to limit the motion of the robot within predefined regions. O pe n A cc es s D at ab as e w w w .ite ch on lin e. co m