Tactile feedback and display system for CT-guided, robot-assisted percutaneous procedures Jeffrey Yanof a, * , Christopher Bauer a , Bradford Wood b a CT Clinical Science Department, Philips Medical Systems, 595 Miner Road, 44139 Cleveland, OH, USA b Diagnostic Radiology Department, National Institutes of Health, USA Abstract. A CT-integrated robot system for interventional procedures is described. A pre-procedure planning screen enabled the radiologist to interactively specify a 3-D virtual needle within a pre- scanned image volume. The virtual needle was specified with a point-and-click interface and included a target and percutaneous insertion points superimposed on transverse axial slices and cross-referenced with multi-planar reformatted views in correlation with the interventional field. After sending the virtual needle’s coordinates to the robot, its needle gripper automatically moved to a position congruent with the planned puncture path. The interventionalist then used a remote needle insertion controller with tactile/haptic feedback to insert the needle along the planned path within an abdominal phantom containing simulated targets and critical structures. During needle insertion, the scanner’s host computer simultaneously displayed the needle imaged during CT fluoroscopy for comparison with the virtual needle. Forces sensed at the needle gripper are fed back to the remote needle insertion controller for haptic feedback, which provided graded manual sensation from the needle to the operator in a remote location. This technology may facilitate biopsy, ablation, brachytherapy and any needle-based image guided therapy. D 2004 CARS and Elsevier B.V. All rights reserved. Keywords: CT-guided; Biopsy; Robotics; CT fluoroscopy; Virtual reality 1. Introduction Tactile (i.e., force or haptic) feedback [1–6] is helpful during certain percutaneous CT- guided procedures such as biopsy and therapeutic procedures such as tumor ablation with radiofrequency, microwave or cryotherapy. When the interventionalist holds the needle with sterile gloves, tissues (such as skin, fat, muscle, lung or liver parenchyma and bone) provide a wide range of tactile feedback by way of needle force resistance. Transitions between tissues (especially upon insertion into a solid tumor that is harder than surrounding parenchyma) can often be felt by the physician and used for confirming position. The interventionalist occasionally ‘‘walks’’ a needle past a rib, transverse process 0531-5131/ D 2004 CARS and Elsevier B.V. All rights reserved. doi:10.1016/j.ics.2004.03.176 * Corresponding author. Tel.: +1-44-048-32481; fax: +1-44-048-37098. E-mail address: jeffrey.yanof@philips.com (J. Yanof). www.ics-elsevier.com International Congress Series 1268 (2004) 521 – 526