Micro_Surgical_Tools.ppt

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Micro_Surgical_Tools.ppt

  1. 1. Precision Design in Surgical Tools Presented by: Hugo Ramirez Eugene Kushnir
  2. 2. Agenda <ul><ul><ul><li>Microsurgery Overview </li></ul></ul></ul><ul><ul><ul><li>Current Designs </li></ul></ul></ul><ul><ul><ul><ul><li>DaVinci Surgical System </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Harmonic Scalpel </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Microsurgical Tele Robotic System </li></ul></ul></ul></ul><ul><ul><ul><li>Future of Microsurgery </li></ul></ul></ul><ul><ul><ul><li>References </li></ul></ul></ul><ul><ul><ul><li>Questions / Comments </li></ul></ul></ul>
  3. 3. Principles for the development of Microsurgery Devices <ul><li>Limits of Human precision </li></ul><ul><ul><li>Involuntary and inadvertent movements </li></ul></ul><ul><ul><li>Noise and error in hand motion </li></ul></ul><ul><li>Convert Procedures to Minimally Invasive </li></ul><ul><ul><li>Increase Precision </li></ul></ul><ul><ul><ul><li>Increase recovery time </li></ul></ul></ul><ul><ul><ul><li>Decrease post-operative pain </li></ul></ul></ul><ul><ul><ul><li>Enhance dexterity </li></ul></ul></ul><ul><ul><li>Enable Remote Participation </li></ul></ul><ul><ul><ul><li>Surgical Systems </li></ul></ul></ul><ul><ul><ul><li>Neuroendoscopy </li></ul></ul></ul>
  4. 4. Analysis of the Microsurgical Environment Table 1. Microsurgical environment general specifications
  5. 5. Analysis of the Microsurgical Environment Figure 1. Microsurgical environment general force specifications
  6. 6. Material Qualities Comparison TABLE 2. MATERIAL QUALITY EXCELLENT N/A * MATERIAL OF CHOICE FOR GEARS IN MOTOR HEADS WHERE WEIGHT AND COST IS IMPORTANT * LIGHT AND SELF LUBRICATING * LOW WATER ABSORBTION <0.5% NYLON 12 (30% GLASS) * GALLING HIGHER THAN STEEL * LOWER MODULUS OF ELASTISITY CAUSES SPRING-BACK * LOWER THAN STEEL DUCTILITY FAIR ANNEALING REQUIRED MOST WIDELY USED ALLOY * MEDICAL TOOLS DIFFERENT COLORS TO PREVENT REFLECTION OF LIGHT (EX. EYE SURGERY) * AEROSPACE * POWER GENERATION IND. * CORROSION RESISTANCE IN NATURAL AND CHEMICAL ENVIRONMENTS * RESISTANCE TO CHLORIDES * RESISTANT TO STRESS CORROSION CRACKING * CAN BE ANODIZED Ti6Al4V TITANIUM (Ti-90, Al-6, V-4) EXCELLENT GOOD ANNEALING REQUIRED * PHARMACEUTICAL * JET ENGINE PARTS * PAPER PROCESSING * MOLYBDENUM ADDS RESISTANCE TO PITTING, SULFURIC AND HYDROCHLORIC ACID, ALKALINE CHLORIDES 316L STAINLESS STEEL CROMIUM = 20% (EXTRA LOW CARBON) EXCELLENT EXCELLENT USUALY NO ANNEALING MOST WIDELY USED SST * SEMICONDUCTOR IND. * SPRINGS * STRESS CORROSION CRACKING ABOVE 60ºC * PITTING IN CHLORIDE ENVIRONMENTS 304 STAINLESS STEEL CROMIUM = 12% FORMABILITY WEDLING USES PROPERTY MATERIAL
  7. 7. Material Properties Comparison TABLE 3. MATERIAL PROPERTIES Rockwell R (1/2&quot; steel ball, 60kg) 108 27.8 305 8702 0.037 NYLON 12 (30% GLASS) 334 4.78 16500 120000 0.163 Ti6Al4V TITANIUM (Ti-90, Al-6, V-4) 146 8.89 28000 34100 0.289 316L STAINLESS STEEL (EXTRA LOW CARBON) 123 9.61 28000 31200 0.289 304 STAINLESS STEEL HARDNESS BRINELL (3000kg) CTE (  in/in-ºF) MODULUS OF ELASTISITY (ksi) YIELD STRENGTH (psi) DENSITY (lb/in^3) MATERIAL
  8. 8. Da Vinci System Overview Illustration courtesy Dr. Akhil Madhani <ul><li>Da Vinci Surgical System – Three arm tele-operated robot </li></ul><ul><li>Degrees of Freedom (DOF) – 34-DOF Total </li></ul><ul><ul><li>Arms – 3-DOF for operation and 6-DOF for initial position on the ports (incisions) plus 4-DOF for the endoscope </li></ul></ul><ul><ul><li>Active End Effector (EndoWrist) – 3-DOF plus grip </li></ul></ul>
  9. 9. DaVinci System Overview (continued) EndoWrist Position Mechanism 0.4 inch Incision
  10. 10. DaVinci Position Actuators – Arm <ul><li>Force-Feedback System </li></ul><ul><ul><li>1. Master Device – Servo-motors and encoders receive input from a surgeon’s hands actuating robotic arms </li></ul></ul><ul><ul><li>2. Slave Device – Arms exert forces back through the console </li></ul></ul>Master Device Surgeon Control System Slave Device EndoWrist Control System
  11. 11. DaVinci Position Actuators – Arm (continued) Click on image to Play/Pause Video Click on image to Play/Pause Video TABLE 3. POSITION SYSTEM PRELOADED - 0° BACKLASH BALL SCREWS ROTATIONAL 180°/sec LENEAR 40 mm/sec SPEED (MAX.) * OPTICAL ROTARY WITH UP TO 2000 COUNTS/REV. * MAGNATIC LINEAR ENCODERS * PRECISION <50  m FEEDBACK SYSTEM (REAL TIME < 35 msec.) REDUCTION 4:1 TO 20:1 TORGQUE 0.15 lbf-ft TO 1.70 lbf-ft BACKLASH 0.7° MOTOR GEAR HEARS (NYLON 12 GEARS FOR 13mm SIZES) 13mm - 35mm MOTORS (TOTAL OF 36 MOTORS) PARAMETERS COMPONENTS/SUBSYSTMES
  12. 12. DaVinci Position Actuators - EndoWrist <ul><li>EndoWrist – 4-DOF </li></ul><ul><li>Motion controlled by tendon like cables to simulate human wrist movement </li></ul><ul><li>Modular design allows various surgical accessories and instruments to be used </li></ul>Ultrasonic Shears
  13. 13. Harmonic Scalpel <ul><li>High frequency ultrasonic energy to actuate the cutting blade. </li></ul><ul><ul><li>Simultaneous cutting and blood coagulation due to high speed </li></ul></ul><ul><ul><li>Advantages: </li></ul></ul><ul><ul><ul><li>Fewer instrument exchanges, </li></ul></ul></ul><ul><ul><ul><li>Improved visibility in the surgical field </li></ul></ul></ul><ul><ul><ul><li>Less tissue charring and dehydration (coagulation occurs at less than 100 º C) </li></ul></ul></ul><ul><ul><li>Disadvantages: </li></ul></ul><ul><ul><ul><li>High initial cost </li></ul></ul></ul>ULTRASONIC SCALPEL BODY DSP CONTROLED ULTRASONIC WAVE GENERATOR (55.5 KHZ)
  14. 14. Harmonic Scalpel (continued) <ul><li>The ultrasonic vibration of the cutting blade is generated by a piezoelectric ceramics that expand and contract under power from a 55.5 KHz wave generator. </li></ul><ul><ul><li>Vibration Range: 50 to 100 µm (function of power level) </li></ul></ul><ul><ul><li>100 µm – Faster cutting less coagulation </li></ul></ul><ul><ul><li>50 µm – Slower cutting more coagulation </li></ul></ul>Tissue
  15. 15. System Overview (Microsurgical Tele Robotic System) <ul><li>Modified Steward type platform for the Micro-manipulator </li></ul><ul><ul><li>6-DOF </li></ul></ul><ul><ul><li>Positional Accuracy - within 50μm </li></ul></ul><ul><ul><li>Workspace - 20mm × 20mm × 20mm </li></ul></ul>Master : Force-reflecting haptic master device. Slave: Surgery micro-manipulator
  16. 16. Microsurgical Tele Robotic System - Slave Stewart Platform Schematic
  17. 17. Microsurgical Tele Robotic System - Master Modified Stewart Platform Schematic X Y Z Base 5 bar Linkage (Ball-Joined –top, Pin-Joined-bottom) Platform End Effector
  18. 18. FUTURE OF MICROSURGERY <ul><li>The New Order of Surgery </li></ul><ul><ul><li>Patient dataset of MRI, CT, and other physiological data </li></ul></ul><ul><ul><li>Systems for interfacing anatomical and physiological data with finite ele-ment modeling tools </li></ul></ul><ul><ul><li>A surgical model to construct a simulation of the surgery </li></ul></ul><ul><ul><li>High Precision Tele-robotic Surgical systems </li></ul></ul>
  19. 19. QUESTIONS / COMMENTS Questions, comments and group discussion
  20. 20. References <ul><li>Chintwood, W. Randolph Jr, MD. “Enddoscopic Robotic Coronary Surgery- Is this Reality or Fantasy?” The Journal of Thoracic and Cardiovascular Surgery. July 1999; Volume 118: 1-3 </li></ul><ul><li>Dong-Soo Kwon, et. al , “Microsurgical Telerobot System” Proc. of the IEEE/RSJ Int. Conf. on Intelligent Robots and Systems ,pp. 945 - 950, 1998 </li></ul><ul><li>Guthart, Gary, Salisbury, Kenneth Jr. “The IntuitiveTM Telesurgery System: Overview and Application” Proc. of IEEE Int. Conf. on Robotics and Automation, pp. 618-621, 2000 </li></ul><ul><li>K.Y.Woo, B.D.Jin, D.S.Kwon, “A 6 DOF Force Reflecting Hand Controller Using the Fivebar Parallel Mechanism,” Proc. of IEEE Int. Conf. on Robotics and Automation, pp. 1597-1602, 1998 </li></ul><ul><li>” Surgical Robots”, National Horizon Scanning Centre, University of Birmingham, Edgbaston, Birmingham, January 2000. </li></ul><ul><li>Yamano Ikuo, et. al , “Method for Controlling Master-Slave Robots using Switching and Elastic Elements” Proc. of IEEE Int. Conf. on Robotics and Automation, pp. 1717-1722, 2002. </li></ul>
  21. 21. References <ul><li>www.intuitivesurgical.com </li></ul><ul><li>www.cybelius.com </li></ul><ul><li>www.thetrocar.net </li></ul><ul><li>www.harmonicdrive.de </li></ul>
  22. 22. Surgical System Applications
  23. 23. Patient care advantages <ul><li>less post-operative pain </li></ul><ul><li>less blood loss </li></ul><ul><li>lower risk for infection </li></ul><ul><li>decreased recovery times </li></ul><ul><li>reduced time in hospital </li></ul><ul><li>enhanced cosmetic results </li></ul>
  24. 24. Motor Specifications
  25. 25. Surgical System video Camera
  26. 26. Block Diagram of EndoWrist
  27. 27. Human Arm Degrees of Freedom
  28. 28. Position Actuator (Microsurgical Tele Robotic System) <ul><li>Harmonic Servo Motor </li></ul><ul><li>Advantages </li></ul><ul><ul><li>Positioning accuracy and repeatability </li></ul></ul><ul><ul><li>Not back-drivable </li></ul></ul><ul><ul><li>Zero-Backlash </li></ul></ul><ul><ul><li>High efficiency </li></ul></ul>Motor in Motion Simulation
  29. 29. Harmonic Servo Motor Operation Principle <ul><li>As soon as the Wave Generator starts to rotate clockwise, the zone of tooth engagement travels with the major elliptical axis. </li></ul><ul><li>When the Wave Generator has turned through 180 degrees clockwise the Flexspline has regressed by one tooth relative to the Circular Spline. </li></ul><ul><li>Each turn of the Wave Generator moves the Flexspline two teeth anti-clockwise relative to the Circular Spline. </li></ul>

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