Interactive Guidance System for C-Arm Repositioning Without Radiation

The problem of repositioning mobile C-arms to defined target locations during surgical procedures currently requires not only time, but also skill and additional radiation exposure. This paper shows a guidance system based on the previously introduced camera augmented mobile C-arm (CAMC). Techniques of visual servoing are applied in order to present the repositioning task in the parameter space of the C-arm. Here we describe a representation for the estimated parameters in order to provide an easy to use interface that helps to speed up relocation procedure in the surgery room. The system which is based on an interactive 3D model, is controlled by tracking visible markers on the patient’s skin using an optical camera attached to the X-ray housing. The visual servoing methods are used to guide the C-arm to target positions by the representation of the interactive visual guidance system. Addititionally, the system provides a number of tools for feedback to assess the required accuracy of the repositioning task. First tests for C-arm repositioning were performed in a laboratory environment.