Robotic Needle End Arm Effector for Integration With CT Scan Team Members: David Sun Chris Willingham Advisor: Dr. Bradford Wood

Problem Definition and Background CT assisted fluoroscopy allows surgical procedures such as tissue biopsy and ablation to be performed with several advantages over traditional techniques (Solomon 2002): The method allows visualization for interventional procedures Procedures are performed in real time The process is faster and more accurate than traditional methods Cases show greater success rates (improved patient outcomes) The primary disadvantage to this method is the radiation exposure received by the physician during the procedure: 2mGy per procedure 500mSv annual limit Each physician is thus limited to 4 procedures per year

Project Statement A robotic system which reduces radiation exposure during CT assisted fluoroscopy while providing greater accuracy and precision is feasible (Cleary and Nguyen, 2001). One of the primary limitations to this system is its ability to place instruments with the “touch” that a skilled physician provides (Stoianovici and Cleary 2002).

Project Goal A successful resolution to this problem will remove the physician from the operating suite, and provide a robotic arm end effector that addresses these factors: It will allow for respiratory motion in the craniocaudal axis. It will allow 6+ degrees of freedom during instrument placement, and free range of motion after placement. It will provide an interface for various instruments at a common joint. Should be easily adaptable to other systems

Current System

Ideal System

Proposed System

Procedural Benefits Increasing the speed and accuracy and decreasing the cost of procedures such as tissue biopsy will allow several profitable benefits: An increased number of routine procedures such as the staging of tumors and hepatitis C can be performed (increased revenue and improved patient outcomes) An expanded schedule in the operating room will allow more cutting edge procedures such as proteomic and genomic analysis of tissue to allow targeting of smart drugs Combination of robotic systems with image guided surgery techniques will one day help to completely automate mundane surgical procedures

Johns Hopkins Robotic System

Current Robotic Arm System Georgetown Robotic Arm Medtronic Robotic Arm

Arm Modification

Proposed End-Effector

Status Analyzed and assembled frame and mounting arm from NIH Analyzing biopsy needle from NIH and redesigning needle interface based on findings Consulted with Physic’s machine shop regarding mechanical arm modification ($200) Patent search for similar devices (micropat.com) Acquiring FLEXBAR device from NIH Searched products that matches our crude solution: Parallel MiniGripper Beginning production of mechanical drawing for the flexible arm and gripper (CAD)

Future Work Appointment with Dr. Lee Gordon and Dr. Ron Price to observe biopsy for operational constraints Continue modification of FLEXBAR to interface with the robotic arm—possible cable attachments, electronic locking Consult with machine shop for possible gripper solution Produce a liver phantom via silicon gel polyurethane Consult with Dr. Bob Galloway for modifications to proposed solution Use SolidEdge™ 2002 to model end-effector for prototype purposes Prototype, testing, and early FDA requirements

Conclusion Current Situation? Problems? Chances of Success? Finished research and brainstorm phase Continuing design and modifications Continue consultation with surgeons and engineers for feedback Refine possible solutions Problems? Respiratory motion in the craniocaudal axis Needle interface Electrical interface necessary for performance Chances of Success? Design idea is progressing well Limiting design to a mechanical prototype to obtain testable results

References Solomon, Stephen, et. al. Robotically Drive Intervention: A method of Using CT Fluoroscopy without Radiation Exposure to the Physician. Radiology 2002. Volume 225-Number 1. Stoianovici, Dan, et. al. AcuBot: A Robot for Radiological Interventions. IEEE-TR&A. Cleary, Kevin, et. al. State of the Art in Surgical Robotics:Clinical Applications and Technology Challenges. Computer Aided Surgery, August 2001. Saadeh, Sherif, et. al. The Role of Liver Biopsy in Chronic Hepatitis C. Hepatology, Volume 33, 2001.

Contacts david.d.sun@vanderbilt.edu jc.willin@vanderbilt.edu David Sun Chris Willingham jc.willin@vanderbilt.edu