1. Robotic Arm for Minimally Invasive Surgery Team: Brenton Nelson, Ashley Huth, Max Michalski, Sujan Bhaheetharan BME 200/300 October 14, 2005

2. Client: Aimen Shaaban, M.D. Assistant Professor of Surgery University of Wisconsin Medical School Advisor: Willis Tompkins, Ph.D. Professor Dept. of Biomedical Engineering University of Wisconsin

3. Overview Current Minimally Invasive Surgery Techniques Current Minimally Invasive Surgery Techniques Current Problems Current Problems Problem Specifications Problem Specifications Proposed Designs Proposed Designs Future Work Future Work Questions Questions

4. Background da Vinci ii da Vinci ii –Surgeon Console –EndoWrist Instruments  Seven degrees of motion  Mimics dexterity of hand and wrist  Motion scaling and tremor reduction Laparoscopic grasper Laparoscopic grasper –3-5mm in diameter shaft –Allows rotation about x- axis –Disposable or reusable –Variety of handles

5. Problems with Current Instruments Price Price Excessive functions Excessive functions Distance from Patient Distance from Patient Cumbersome Cumbersome –Limited patient access Set up time/training Set up time/training Possibility of being outdated Possibility of being outdated Da Vinci ii Limited sense of tension and pressure Limited sense of tension and pressure Difficult to perform certain tasks Difficult to perform certain tasks Uncomfortable Uncomfortable Takes endurance to use Takes endurance to use Laparoscopic Grasper

6. Problem Specifications Mimic wrist and hand movements Mimic wrist and hand movements Simultaneously rotates graspers in all directions Simultaneously rotates graspers in all directions Provide accurate tactile feedback Provide accurate tactile feedback Simple operation by user Simple operation by user Fully operable by one hand Fully operable by one hand Maximum diameter for surgical shaft 5mm; goal 3mm. Maximum diameter for surgical shaft 5mm; goal 3mm.

7. Prototype 1: Trigger Control “Pen-click” closed clamp “Pen-click” closed clamp Trigger for simultaneous rotation and translation Trigger for simultaneous rotation and translation Rotation and translation about x, y, and z axis Rotation and translation about x, y, and z axis

8. Prototype 1 (continued) Pros Pros –Single finger control for rotation –The –“Pen-click” clamps grasper without continuous applied pressure –Provide accurate feedback –Easy to use –Ergonomically beneficial Cons Cons –Not reusable –Expensive

9. Prototype 2: Double Trigger Trigger Clamped Trigger Clamped Trigger rotation in y, and z-axis Trigger rotation in y, and z-axis Rear spin knob for rotation in x-axis Rear spin knob for rotation in x-axis

10. Prototype 2 (continued) Pros Pros –Simultaneously clamps and bends –Ergonomic –Reusable –Tactile Feedback Cons Cons –Expensive –Complex trigger mechanism, requires multiple digits

11. Prototype 3: Joystick Control Joystick translates to grasper Joystick translates to grasper Simultaneous rotation in x, y, and z direction Simultaneous rotation in x, y, and z direction Guided tracks for smooth movements Guided tracks for smooth movements Trigger mechanism Trigger mechanism

12. Prototype 3 (continued) Pros Pros –Translates joystick motion to graspers – Easy sewing motion Cons Cons –Lack of tactile feedback –Lacks precision –Thumb fatiguing

13. Design Matrix

14. Future Work Finalize dimensions and materials Finalize dimensions and materials Build Final Prototype Build Final Prototype Test Prototype Test Prototype

15. Questions?