Registration and motion compensation of a needle placement robot for CT-guided spinal procedures

Computed tomography (CT) guided needle placement is an established practice in the medical field. The efficacy of these procedures is related to the accuracy of needle placement. Current free-hand techniques have limitations in accuracy, which is often affected by the patient motion. In response to these problems and as a testbed for future developments, we propose a robotically assisted needle placement system consisting of a mobile CT scanner, a needle insertion robot, and an optical localizer. This paper presents the overall system concept and concentrates on the system registration and compensation of the patient motion. Accuracy results using an abdominal phantom are also presented.