Pneumatically Driven Robot System with Force Perception for Minimally Invasive Surgery

Transcription

1 Pneumatically Driven Robot System with Force Perception for Minimally Invasive Surgery Tokyo Institute of Technology Kotaro Tadano Daisuke Haraguchi Kenji Kawashima

2 Research Overview on Surgical Robots Univ. of Tokyo davinci Intuitive Surgical, Inc Nagoya Univ. Univ. Washington DLR SRI Display the sense of force to the operator is a problem

3 Master-Slave Surgical Assist Robot Named IBIS Feature Compact Having Force Display

4 Purpose Pneumatic actuators Flexible due to air compressibility High power / weight ratio Available without reduction mechanism High back drivability Susceptible to friction Estimation of force by pressure We propose a master-slave system with multi-dof forceps manipulators that is able to provide a force display to operators without a force sensor using pneumatic actuators.

5 Concept of the forceps No sensors Pneumatic actuator Effective for a haptic device due to the facility in measurement and control of their driving force Enable the estimation of the external force from the driving force and the impedance.

6 Development histories of IBIS Ver.1 IBIS I 2004 Ver.3 IBIS III 2007 Ver.5 IBIS V 2010 Ver.2 IBIS II 2005 Ver.4 IBIS IV

7 Forceps manipulator Pneumatically-driven forceps manipulator with a 2-dof flexible wrist joint Pneumatic cylinder x 4 Driving part 450 mm φ10 mm Tip part 22 mm 33 mm Potential of external force estimation due to high back-drivability flexible joint Gripper Overview of the forceps manipulator The flexible joint bent by 90

8 Pneumatic driving system Position of cylinder piston Air pressure Pneumatic driving force Schematic of pneumatic driving system 8

9 Developed Gripper Embedded with Pneumatic Cylinder Avoidance of interference with the other joints Slider-crank mechanism driven by a pneumatic cylinder Strong gripping force using singular point τ θ [mnm] Opening angle of grasping a needle Fig. : Gripping Mechanism θ [deg] Fig. Gripping torque vs. angle (0.6MPa)

10 Manipulator to support forceps and scope Table Working range and maximum force/torque φ ψ ρ θ working range ±52 ± 50 ± 50mm ± 120 force / torque 3.6Nm 5.5Nm 39N 0.14Nm Fig. Developed manipulator for supporting forceps 4-DOF Combination of parallel link and gimbal mechanism Position of a trocar is immovable mechanically Easy power adjustment with a regulator valve

11 Master slave system Fig. Configuration of Master-Slave System Position Force Master device Electrically - driven Slave Manipulator Pneumatically - driven Integration of Pneumatic and Electric system

12 Experimental results during suturing task Ms=0.01[kg], Bs=0.02[Ns/mm], Ks= 0.4[N/mm] Mm=0.4[kg], Bm=0.005[Ns/mm] Fig. Experimental results of bilateral control Force between the master and slave side agree well

13 In vivo experiment with the robot system

14 Force feedback during suturing task Effectiveness of the system is confirmed with in vivo experiment

15 Laparoscope camera control system Named AeroVison

16 Laparoscope control system Advantages 1. Display of clear 3D view to the operator 2. Realize an intuitive operation 3. Contribution to safe operation with the detection of external forces 4. No need of assistant.

17 Proposed laparoscope control system To right and left 3D view with HMD Track head movement Rotation Up and down Back and forth Laparoscopic camera

18 System setup

19 System controller Fig. Schematic diagram of control system Calculate the reference velocity at the tip of scope from the gyro sensor on HMD PD control is used to track the reference angle

20 Clinical trial of AeroVision Tested with and without HMD AeroVision worked successfully

21 Conclusion We developed slave forceps manipulator that has 6-DOFs driven by pneumatic actuators with flexible joint. For the pneumatic slave manipulator, force control type of the impedance control without force sensor was adopted. The bilateral control experimental results indicated that the operator felt the force at the slave side with sensitivity of about 0.3N. Effectiveness of force feedback is confirmed with ligation experiment. 3D endoscope control system with gyro sensors is developed.