UC San Diego

Image-guided surgery (IGS) enables accurate and safe minimally invasive treatment of diseases, including cancer and chronic pain, with needle-like tools via a percutaneous approach. During a percutaneous IGS, the physician plans, inserts, and adjusts the needle with image feedback to help them “close the loop” and compensate for the accuracy limitation of free-hand adjustment and patient physiological motion. When performed with Computed Tomography (CT) guidance, robots provide high positional accuracy, enabling fewer intermediate control scans and lower radiation doses. To fit into the clinical workflow, the robots must be simple to set up and operate within the confined imaging bore while retaining sufficient dexterity to insert and manipulate the needle. This thesis explores CT-guided needle insertion, focusing on technologiesrequired for dexterous manipulation of needles within an imaging bore, considering the interplay between device kinematics, mechatronics, planning, and control. The clinical problem and existing guidance technologies are reviewed. From this, abstract and measurable clinically motivated metrics for in-bore dexterity applicable to general-purpose intra-bore image-guided needle placement robots are defined and applied to different procedure areas. Two generations of redundant CT-compatible robots are developed and tested both on bench-top and in-situ. The designs’ ability to meet clinical requirements is analyzed. Specifically, it is demonstrated that the redundant linkage design provides dexterity across various human morphology, and that the transmission, sensing, and the control meets the clinical requirements for target accuracy during an in-situ evaluation. Finally, methods for automated robot planning and control for intra-bore needle manipulation from image guidance are explored.