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

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).

Problem Definition 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

Background

Project Goal A successful resolution to this problem will remove the physician from the operating suite while addressing three main factors: It will allow for respiratory motion in the craniocaudal axis. It will provide an interface for various instruments at a common joint. It will allow 6+ degrees of freedom during instrument placement, and free range of motion after placement.

Proposed Solution We propose to modify an existing heart stabilizer to serve as the end arm effector for a surgical robot, providing and instrument which will: Accommodate a variety of needle gauges Provide an instrument which is rigid during needle placement, yet unlocks rapidly after placement to allow appropriate ROM Interface with a specific robotic arm, but be easily adaptable to fit other systems

Procedural Example Hepatitis C virus affecting 175 million people globally 80% develop chronic hepatitis C 8,000 – 10,000 deaths annually in US No accurate noninvasive markers of the disease Liver biopsy is used to establish the stage of the liver disease Majority of patients with chronic hepatitis C will require a liver biopsy

Status Weekly conference call with our advisor Literature review Patent search for similar devices (micropat.com) Obtaining Medtronic robotic arm Obtaining FlexSite device (Heart Stabilizer) Obtaining biopsy needles (17 & 22 gauge) Training SolidEdge program for future CAD design Updated all information on website

System Flowchart

Future Work Appointment with Dr. Lee Gordon to observe biopsy for operational constraints Continue modification of heart stabilizer to interface with the robotic arm—possible cable attachments, electronic locking Consult with machine shop for possible interface solutions 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? Interfacing with multiple robotic arms 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 Sun david.d.sun@vanderbilt.edu Chris Willingham jc.willin@vanderbilt.edu