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Active Wrists Endoscope Navigation in Robotized Laparoscopic Surgery
ACTIVE WRISTS ENDOSCOPE NAVIGATIONIN ROBOTIZED LAPAROSCOPIC SURGERY
Enrique Bauzano Núñez, Dr. Víctor Muñoz MartínezDra. Isabel García Morales, Belén Estebanez Campos
Dpto. Ingeniería de Sistemas y Automáticahttp://www.isa.uma.es
Universidad de Málaga (Spain)
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Enrique Bauzano Nuñez [email protected]
Active Wrists Endoscope Navigation in Robotized Laparoscopic Surgery
OUTLINE
I. Introduction
II. Laparoscopic Navigation on Active Wrists
III.Force Interaction Model
IV.Control Strategy
V. Implantation and Experiments
VI.Conclusions and Future Works
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Enrique Bauzano Nuñez [email protected]
Active Wrists Endoscope Navigation in Robotized Laparoscopic Surgery
I. INTRODUCTION
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I. Introduction
Laparoscopic Surgery: “Accessing to the abdominal cavity with especial long instruments.”
LAPAROSCOPIC SURGERY
Advantages Lessen recovery time
Limit post-operative complications
Lower scars
Constraints Movement limitations
Loss of touch and 3D perception
Hand-eye coordination problems
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I. Introduction
Proposal: “Solve the motion problem for a laparoscopic surgery robot assistant with an actuated wrist.”
GLOBE-SHAPED MOVEMENTS
{I} Fulcrum point Orientation angle Altitude angle External distance
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ROBOTIC WRISTS COMPARATIVE
• Null forces on abdomen• Precision depends on fulcrum accuracy
• Null forces on abdomen• Special instruments needed• Previous calibration• Voluminous mechanisms
• No additional mechanisms on wrist• No special instruments needed• Low volume• May apply forces on abdomen
I. Introduction
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Active Wrists Endoscope Navigation in Robotized Laparoscopic Surgery
II. LAPAROSCOPIC NAVIGATIONON ACTIVE WRISTS
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NAVIGATION PROBLEM
I
XI
ZI
CC
e
AB
es
Navigation Problem: Move the endoscope from A to B an altitude angle .
I0
I0 Initial fulcrum (desired)
I Actual fulcrum
C Estimated fulcrum
e External distance error
es Separation error
II. Laparoscopic Navigation on Active Wrists
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ERROR ANALYSIS
Separation Error: When estimated fulcrum C differs from real location I0, external distance error e forces a fulcrum displacement es over the abdomen, which can be geometrically analyzed.
0 10 20 30 40 50 60 70 80 90
5
10
15
20
25
30
35
40
45
50
Altitude (degrees)
Sep
arat
ion
Erro
r es (m
m)
es = e' tan
50
25
10
e' = 5 tanees
II. Laparoscopic Navigation on Active Wrists
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Active Wrists Endoscope Navigation in Robotized Laparoscopic Surgery
III. FORCE INTERACTION MODEL
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ENDOSCOPE-ABDOMEN INTERACTION MODEL
XI
ZI
Fr
III. Force Interaction Model
rs FFgF m
A
Cmg
I0
Fs
I
B
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FORCES MODEL
Stiffness Coefficient
0 0.5 1 1.5-3
-2
-1
0
1
2
3
4
Time (seconds)
Ela
stic
ity
(N/m
m)
Real Estimated
-20
0
20
00.5
11.5
2
0
2
4
6
8
10
Altitude (degrees)Time (seconds)
Fric
tion
F r (New
ton)
ss eF NFr
III. Force Interaction Model
Friction Coefficient
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Active Wrists Endoscope Navigation in Robotized Laparoscopic Surgery
IV. CONTROL STRATEGY
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NAVIGATION STRATEGY
1. Rotate around estimated fulcrumFulcrum displacement over the abdomen
2. Passive Wrist BehaviorEndoscope rotation over the wrist to reduce fulcrum displacement
3. Altitude angle correctionRecover desired altitude angle
I
L1L3
XI
ZI
C
IV. Control Strategy
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PASSIVE WRIST BEHAVIOR (I)IV. Control Strategy
Planner Robot
Abdomen Interaction
Force Sensor
Separation estimator
External Distance estimator
KFriction + Weight
Filtering
Cor
rect
ion
Ang
le
Planned Movement
Followed Altitude
Abdomen Force Fs Force F
Planned Altitude p
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PASSIVE WRIST BEHAVIOR (II)IV. Control Strategy
Planner– Calculates the required trajectory with a first order system behavior– Acts faster than correction angle loop
Robot: Performs the controlled movement
Endoscope-Abdomen Interaction: Generates abdominal forces
Force Sensor: Measurement of forces
Separation Estimator– Depends on the stiffness estimation– Its value remains the same if Fs < Fthreshold
External Distance Estimator– Result of Force-Torque balance– Its value remains the same if Fs < Fthreshold
rT
sT
s LekLekL )1()()1(
e
ssFe
Ce
sρ
s
FuM
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SPHERICAL CONTROL LOOPIV. Control Strategy
Passive Wrist Behavior Robot
Followed Altitude
Control PI
+-
Desired Altitude d
Planned Altitude p
Controlled Altitude c
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Active Wrists Endoscope Navigation in Robotized Laparoscopic Surgery
V. IMPLANTATION AND EXPERIMENTS
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IMPLANTATION (I)V. Implantation and Experiments
Movement Command
Virtual-PA10 simulator (Matlab)
Matlab-C++ DLL Library
linker
C++ Library PA-10 ControllerPA-10 Robot
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IMPLANTATION (II)V. Implantation and Experiments
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EXPERIMENTAL RESULTS
0 2 4 6 8 100
0.5
1
1.5
2
2.5
3
3.5
Time (seconds)
Sepa
ratio
n Er
ror e
S (mm
)
V. Implantation and Experiments
0 2 4 6 8 10266
268
270
272
274
276
278
Time (seconds)
Exte
rnal
Dist
ance
e (
mm
)
EstimatedReal
0 1 2 3 4 5 6-49
-48
-47
-46
-45
-44
-43
-42
-41
-40
Time (seconds)
Alti
tude
(d
egre
es)
Desired Followed
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Active Wrists Endoscope Navigation in Robotized Laparoscopic Surgery
VI. CONCLUSIONS AND FUTURE WORKS
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Active Wrists Endoscope Navigation in Robotized Laparoscopic Surgery
FUTURE WORKS
Active tasks during an intervention
Development of semi-autonomous robotic surgeon assistants
Like remote-centered wrists, useful on tele-surgery fields
CURRENT STATUS
System does not depend on friction force
Stiffness can be now measured on-line, not model needed