robot for skull-base surgery · robot for skull-base surgery. neurosurgery • commercially...
TRANSCRIPT
By: Charles Lo Vui Hong
Robot for Skull-Base Surgery
NeurosurgeryNeurosurgery
•• Commercially available systems Commercially available systems ((eg.Neuromateeg.Neuromate, , RobodocRobodoc, , AcrobotAcrobot) are ) are lacking in the degrees of freedom required lacking in the degrees of freedom required for skull base surgeryfor skull base surgery
•• Large workspace leads to unconstrained Large workspace leads to unconstrained motion that may pose a danger to patient motion that may pose a danger to patient and surgeonand surgeon
Introduction to Skull Base SurgeryIntroduction to Skull Base Surgery
Involves drilling of the temporal boneInvolves drilling of the temporal boneTo access deep seated skull base tumorsTo access deep seated skull base tumorsOne of the longest operations in One of the longest operations in
neurosurgery(8neurosurgery(8--13 hours)13 hours)
Posterior Cranial Posterior Cranial FossaFossa7th & 8th Nerves
CerebellopontineAngle
CerebellumSigmoid Sinus
Cochlea
Semicircular Canals
Mastoid
Acoustic Acoustic NeuromasNeuromas
Medium-sized Acoustic Neuroma
Common Surgical ApproachesCommon Surgical Approaches
TranslabyrinthineTranslabyrinthine ApproachApproach
Skull Base SurgerySkull Base Surgery
System ModulesSystem Modules
NeuroBotNeuroBot SystemSystem
NeuroBaseNeuroBase NeuroPodNeuroPod NeuroVisionNeuroVision NeuroRaTNeuroRaT
Robot Controller
Base Structure
Manipulator
7th DOF
Drill Unit
Force Sensor
VolumeVisualization
Robot UserInterface
Path Planning
TrackingDevice
PatientMarkers
RobotMarkers
DigitizingProbe
SurgicalNavigation
SurgeonSurgeon
Robot User Interface
Multi-Modal Images
3-D Images
Path-Planning
NeuroVisionNeuroVisionCT/MRI/MRA
Images
DextroScope
NeuroPodNeuroPodForce Feedback
HexapodHexapod
7th DOF
Drill Unit
NeuroBaseNeuroBase
Robot Controller
Base StructureBase Structure
Proposed SystemProposed System
Patient Tracking
Robot Tracking
Surgical Tool Tracking
Surgical Navigation
NeuroRATNeuroRAT
PatientPatient
Registration ErrorsRegistration Errors“During patient registration, surgeons strive to
minimize a number provided as feedback by the registration system. Unfortunately, this measure of error is merely an estimate of the accuracy of the
rigid body transformation. This estimate informs the operator only of error in the geometric alignment of the fiducial markers registered. Reliance on this
number as a proxy for the accuracy of the computer-assisted navigation during sugery is naïve
at best. At worst, the values may be misleading, especially with respect to the target registration error (TRE) which is of paramount importance
clinically.”
Physical Space {P} Image Space {I}
Combined Space
Fiducial Registration Error
(FRE)
After Registration
Physical Space {P} Image Space {I}
Combined Space
After Registration
Target Registration Error(TRE)
Sub-Module: Patient Markers
NeuroRATNeuroRAT
NeuroRATNeuroRATSub-Module: Digitizing Probe
NeuroRATNeuroRAT
NeuroPodNeuroPod
Sub-Module: Manipulator Description:Description:
6 axis parallel 6 axis parallel kinematickinematic robot (Hexapod)robot (Hexapod)
•• micron resolutionmicron resolution• small workspacesmall workspace•• high stiffnesshigh stiffness(Fraunhofer-Institut Produktionstechnick and Automatisierung)
Function:Function:
To move drill unit along a specified drill trajectoryTo move drill unit along a specified drill trajectory
Workspace Analysis
Workspace Analysis
⎥⎥⎥⎥⎥⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢
⎣
⎡
=
maxmaxmax
minmaxmax
maxminmax
minminmax
maxmaxmin
minmaxmin
maxminmin
minminmin
ψθφψθφψθφψθφψθφψθφψθφψθφ
G
Iteration 1
Iteration 2
Iteration 7
Workspace Analysis
Iteration 8
Iteration 12 Iteration 28
Iteration 32
Iteration 2
NeuroBaseNeuroBase –– 11stst PrototypePrototype
Description:Description:
Hybrid parallel serial system with Hybrid parallel serial system with decoupled motionsdecoupled motions
Function:Function:
To place To place NeuroPodNeuroPod rigidlyrigidly in optimum in optimum working volume to maximize use of working volume to maximize use of Hexapod’s workspaceHexapod’s workspace
{B}
{T}
{H}
{W} Optotrak
Base Robot
Hexapod
Bone-RemovalTool
A = RpbAt = bAh
hAt
Robot RegistrationRobot Registration
{W}
{M}
pimpi
wpm
wpi
Markers
Path / Task-Envelope
S
I
R
L
P
A{M}
{V}
pimpi
vpm
vpi
Skull-Base
Markers
Point on Path’sBoundary
(Offset View)
Virtual ReferenceFrame
mPe = vPe - vpmwhere P = [pi, pi+1, …, pn]T
{T}
Hexapod
Bone-RemovalTool
{W}
pi
tAe
wAt
wAe
Path / Task-Envelope
{E}
{B}
{T}
{E}tAe
bAt’
bAteAf
Best Fit PosebRt’ eRfbpt’ epf
SubSub--Module: Module: Path PlanningPath PlanningManual (Manual (DextrascopeDextrascope))
CONSTRAINT TASKCONSTRAINT TASK--ENVELOPEENVELOPECONSTRUCTION (CONSTRUCTION (CONTECCONTEC))
Target Spot
Critical Bounds
General Direction of Action
Encapsulating Matrix/ Medium
Problem Formulation and Representation
SubSub--Module: Module: Path PlanningPath PlanningAutomatic (CONTEC)Automatic (CONTEC)
SubSub--Module: Path Planning (1)Module: Path Planning (1)CONTECCONTEC
ri
EiVoronoiVertex
VoronoiSkeleton
Line of Action
D2
D1
l1|m
li-1|m
li|m
li+1|m
ln|m
Line of Action BODm
SubSub--Module: Path Planning (1)Module: Path Planning (1)CONTECCONTEC
li|1 li|mli|m-1 li|m+1 li|o
ImD1
D2
Line-of-ActionLine-of-Action
Cavity Bound)(upperθ
)(lowerθ
Target Spot
Slices
Upper Fulcrum Point
Lower Fulcrum Point
θ4
li|1 li|mli|m-1 li|m+1 li|o
3rd Fulcrum Point
4th Fulcrum Point
θ3
SubSub--Module: Path Planning (1)Module: Path Planning (1)CONTECCONTEC
Conduit Vector 1
Conduit Vector 2
Straight Tool
Contact Line of Tool
Inaccessible Areas
PROBLEMPROBLEM
CL1
li|1 li|mli|m-1 li|m+1 li|o
CL2
ϕ
ϕ
FP4
FP3 FP1
FP2
CL1’
CL2’
SubSub--Module: Path Planning (1)Module: Path Planning (1)CONTECCONTEC
ϕ = min ( maxminmaxminmaxmin ,,,,, ψψθθφφ )CL1
li|1 li|mli|m-1 li|m+1 li|o
CL2FP4
FP3 FP1
FP2
OutlyingPoints
AmendedPoints
SubSub--Module: Path Planning (1)Module: Path Planning (1)CONTECCONTEC
li|1 li|mli|m-1 li|m+1 li|o
Final Boundary
Four main properties are inherent for the constructed conduit:•It avoids all critical areas/bounds;•Allows for maximal line of sight;•Alleviates areas which are inaccessible;•Takes into account the rotational ability of the parallel manipulator.
SubSub--Module: Path Planning (2)Module: Path Planning (2)ABNOABNO
SubSub--Module: Path Planning (2)Module: Path Planning (2)ABNOABNO
SubSub--Module: Path Planning (2)Module: Path Planning (2)ABNOABNO
ei-1
ei
ei+1
ei+2
Vi-1
Vi
Vi+1
Vi+2
Vi+3bi
bi+1
bi+2
bi’
Ii
Vi+4
bi+3
ei+1
ei-1
ei+2
ei+3
ei+3Ii+2
VVnn --> e> enn--11 , e, en n ((bbnn))....
IIii --> > eeii--11 , , eei+1i+1 ((bbii’’))
VVii--1 1 --> > eeii--22 , , eeii--11
((bbii--11))
..
..VV11 --> e> enn , e, e1 1 (b(b11))
LAVLAV22
VVnn --> e> enn--11 , e, en n ((bbnn))....
VVi+1i+1 --> > eeii , , eei+1i+1
((bbi+1i+1))
VVii --> > eeii--11 , , eeii ((bbii))
VVii--1 1 --> > eeii--22 , , eeii--11 ((bbii--
11))
..
..VV11 --> e> enn , e, e1 1 (b(b11))
LAVLAV11
List of Active Vertices
eei+i+
33
eei+i+
11
VVi+i+
33
VVi+i+
22
IIi+2i+2
..........eei+i+
11
eeii--
11
VVi+i+
11
VViiIIii
eebbeeaaVVbbVVaaIntersectionIntersectionPtsPts
Priority Queue
Vi+2
Vi+3
X
X
Output SkeletonOutput Skeleton
VaI, VbI
SubSub--Module: Path Planning (2)Module: Path Planning (2)ABNOABNO
SubSub--Module: Path Planning (2)Module: Path Planning (2)ABNOABNO
SubSub--Module: Path Planning (2)Module: Path Planning (2)ABNOABNO
CurvelinearCurvelinear ToolpathsToolpaths
Current StatusCurrent Status►► Grant from Biomedical Research Council of AGrant from Biomedical Research Council of A--StarStar►► Ready for Animal/Ready for Animal/CadavericCadaveric Clinical TrialsClinical Trials►► Feasibility Studies to extend applications to Feasibility Studies to extend applications to
NeuroendoscopyNeuroendoscopy, , StereotacticStereotactic Biopsy, Biopsy, NeuroNeuro--OsteotomiesOsteotomies, Pedicle Screw Placements, , Pedicle Screw Placements, Craniotomies, VP Shunt Insertions, maybe even Craniotomies, VP Shunt Insertions, maybe even stemcellsstemcells implantation!implantation!
Current Members:Current Members:Principal Investigators: Dr. Ivan Ng & Charles LoPrincipal Investigators: Dr. Ivan Ng & Charles LoCollaborators:Collaborators:
Volume Interactions:Volume Interactions:NanyangNanyang Technological UniversityTechnological UniversitySingapore Institute of Manufacturing TechnologySingapore Institute of Manufacturing Technology
Thank You……..Thank You……..