Pneumatically Driven Robot System with Force Perception for Minimally Invasive Surgery

Pneumatically Driven Robot System

with Force Perception for

Minimally Invasive Surgery

Tokyo Institute of Technology

Kotaro Tadano

Daisuke Haraguchi

Kenji Kawashima

Research Overview on Surgical Robots

Univ. of Tokyo

Nagoya

Univ.

Univ. Washington

DLR

SRI

Display the sense of force to the operator is a problem

daVinci

Master-Slave Surgical Assist Robot

Named IBIS

Feature

・

Compact

Purpose

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.

Pneumatic actuators

Estimation of force by pressure

Susceptible to friction

High back drivability



Flexible due to air compressibility



High power / weight ratio

Concept of the forceps

•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.

No sensors

Development histories of IBIS

Ver.3

IBIS III 2007

Ver.1

IBIS I

2004

Ver.2

IBIS II

2005

2004

2012

Ver.4

IBIS IV 2009

Ver.5

IBIS V

2010

2008

Forceps manipulator

Pneumatically-driven forceps manipulator with a 2-dof flexible

wrist joint



Potential of external force

estimation due to high

back-drivability

450 mm

φ10 mm

Driving part

22 mm

33 mm

flexible

joint

Gripper

Tip part

Pneumatic

cylinder x 4

Overview of the forceps manipulator

Pneumatic driving system

8

Pneumatic driving force

Position of cylinder piston

Schematic of pneumatic driving system

Developed Gripper Embedded with Pneumatic Cylinder

Fig. : Gripping Mechanism

Fig. Gripping torque vs. angle (0.6MPa)

0

4

8

12

100

200

300

θ

[deg]

τ

[m

Nm

]

Opening angle

of grasping a

needle

•Avoidance of interference

with the other joints

• Slider-crank mechanism driven

by a pneumatic cylinder

•Strong gripping force

using singular point

Manipulator to support forceps and scope

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

Table Working range and maximum force/torque

•

4-DOF

• Combination of parallel link

and gimbal mechanism

•

Position of a trocar is

immovable mechanically

•

Easy power adjustment

with a regulator valve

Master slave system

Fig. Configuration of Master-Slave System

Integration of Pneumatic and Electric system

Slave Manipulator

Pneumatically

-

driven

Master device

Electrically

-

driven

Position

Force

Kagawa-Kawashima Group, Precision and Intelligence Laboratory, Tokyo Institute of Technology

12

Experimental results during suturing task

Fig. Experimental results of bilateral control

M

s=0.01[kg], Bs=0.02[Ns/mm],

K

s= 0.4[N/mm]

M

m=0.4[kg],

B

m=0.005[Ns/mm]

Force between the master

and slave side agree well

Force feedback during suturing task

Effectiveness of the system is

confirmed with in vivo experiment

Laparoscope camera control system

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

Proposed laparoscope control system

Back and forth

To right and left

Rotation

Laparoscopic camera

3D view with HMD

Up and down

Track head

movement

System controller

•

Calculate the reference velocity at the tip of scope from

the gyro sensor on HMD

•

PD control is used to track the reference angle

Clinical trial of AeroVision

Tested with and without HMD

AeroVision worked successfully

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.