Image Guided Robotic Biopsy

1. Image Guided Robotic Biopsy Group Members: Ryan Augustine Nate Gaeckle Brian Frederick Gordy Lawrence Advisor: Professor Willis Tompkins Client: Dr. Myron Pozniak

2. Abstract A robotic arm has been developed to eliminate the humans errors of biopsies The Robotic Arm advances the needle slowly Causes tumor movement and inaccurate biopsies Increases risk of internal injury We designed a pneumatic driver that should quickly insert and remove the needle Three prototypes have been assembled Needle retrieval and sampling designs have yet to be built

3. Motivation Problems with current drive mechanism Slow needle advancement: 2 cm/s Slower biopsies increases risk of internal damage Creates tumor movement Makes use of the robotic arm infeasible

5. Problem Definition Biopsies are used in conjunction with a CT scan Many dilemmas with manual biopsy needle injection Inaccurate Physician exposure to radiation Sometimes multiple attempts at tumor capture Robotic Arm created to eliminate these problems

6. Problem Statement Our goal is to create a needle driver that: Drives a needle fast to counter tumor movement and patient injury Retracts the needle with speed and ease with a sample of the tumor Is compatible with CT scanners Preserves Imageguide Inc.�s Remote Center of Motion for the Robotic Arm

7. Design Criteria Device must not be any longer than 30 cm Radiolucent material Must have redundant safety checks Needle must be extracted rapidly with tissue sample Needle must be fired fast enough to utilize inertia of body tissue Biopsy should be completely automatic

8. Current Design Needle contained inside piston/cylinder assembly Needle injected and retracted via pneumatic power Meets length restrictions Most parts may be constructed from plastic

9. Internal view of final pneumatic firing system Needle inside cylinder Needle able to inject or retract based on direction of air flow

10. Testing with Metallica Tested needle deflection through the soft portion of a pig�s foot and gelatin Needle velocity estimated at 4 m/s at ~5psi 2000-4000 lbs/in2 generated at needle tip Needle bent on first trial into pig�s foot

11. Silver Bullet vs. The Turkey Breast Shot through easily with no apparent deflection at various heights Shot at 30 psi More pressure was needed for the prototype to be successful

12. Silver Bullet vs. The Pig Qualitative assessment for a proper distance from patient Enhanced performance as pressure increased 50 psi worked the best Compromises material selection Tested on wide range of tissues No variability in needle behavior

13. Retraction Mechanism Solenoid valve alternates air flow to retract needle Compressed air Vacuum line Retroreflector sensor senses when needle is at the end of the tube causes the solenoid valve to switch to vacuum line

14. Needle Designs

15. Future Work Design mechanism within plunger to cause biopsy needle to capture tissue Implement valve to direct air flow Design mechanism to sequence firing and retracting Implement radiolucent material Interface with ImageGuide robotic arm Needles of different length

16. References ImageGuide, Inc. Feb. 16, 2004. Image-Guided Robotics for Minimally Invasive Cancer Diagnosis and Therapy. PowerPoint Presentation. Chesler, N. 2004. Personal Interview Fronczak, F. 2004. Personal Interview Pozniak, M. 2004. Personal Interview Sidney, D. 2004. Personal Interview Webster, J. 2004. Personal Interview

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