![Page 1: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/1.jpg)
Image Based-Mesh Generation for realistic Simulation of theTranscranial Current Stimulation
Ash HarkaraBusiness Manager
Presented at the COMSOL Conference 2008 Hannover
![Page 2: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/2.jpg)
Presentation overview
Case study
Software solutions
Company overview
Summary
![Page 3: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/3.jpg)
Company overview
![Page 4: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/4.jpg)
Simpleware
Founded in December 2000
Based in Exeter, United Kingdom
Global customer base
World-wide reseller network
Develop and Sell world-leading image processing environment for the conversion of 3D images into models
![Page 5: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/5.jpg)
For conversion of 3D images into high quality models and meshes,which can be directly used for:
What we provide: Software
Computer Aided Design (CAD )
Finite Element Analysis (FEA)
Computational Fluid Dynamics (CFD)
Rapid Prototyping (RP)
![Page 6: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/6.jpg)
What we provide: Services
Scanning and conversion services:Phillips fMRI ScannerSpiral CT ScannerConverted to FEA, CFD, and/or STL and CAD files
RP production of parts in:Polymer (Laser SinterStation)Metal (Selective Laser Melting Machine)
Software development & support:Adaptation of technology for tailored solutionsFull technical support
![Page 7: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/7.jpg)
Industries Applications
Image-based meshing software and services for industrial applications in:
•Materials•Natural Sciences•Medical
![Page 8: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/8.jpg)
Process:Software solutions
![Page 9: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/9.jpg)
Scan data
FE/CFD mesh & surface model
Process overview - from scan to model
Meshing
Imageprocessing
![Page 10: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/10.jpg)
ScanIP softwareImage Processing/Segmentation
Import industrial CT, MicroCT, X-ray tomography (XMT) files
Segmentation
Visualisation of complex data sets
Conforming multi-part watertight STL meshes
Accuracy contingent only on image quality
Low distortion tesselation
![Page 11: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/11.jpg)
+ScanFE moduleFE/CFD mesh generation
Single-step conversion to
multi-part volumetric mesh
User defined adaptive
meshing
Assignment of complex
material properties based
on signal strength
Direct export to Abaqus,
Ansys, Fluent, COMSOL,
etc.
(no re-meshing necessary)
FE model is exact replica of
the STL
![Page 12: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/12.jpg)
+ScanCAD moduleImport and positioning of CAD dataFeatures and benefits:
Direct import of most common CAD formats and support of multiple CAD imports
Intuitive 3D positioning widget
Export of multi-part STL models (e.g. bone – implant)
Automated meshing for FE/CFD analysis
![Page 13: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/13.jpg)
Proximal humerus fracture
Segmented masks from scan and imported CAD implant
![Page 14: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/14.jpg)
Applications and Case study
![Page 15: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/15.jpg)
TRANSCRANIAL CURRENT STIMULATION
![Page 16: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/16.jpg)
TCS is the application of currents delivered through the scalp to modulate brain activity.
WHAT IS TRANSCRANIAL CURRENT STIMULATION ??
![Page 17: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/17.jpg)
Benefits of TCS :
Actively explored as a non-invasive therapeutic option for the treatment of neurological/psychological diseases…including depression, stroke, epilepsy, learning disorders, relieving pain.
Currently used clinical protocol is ‘unfocal’
A critical factor for TCS ‘efficacy’ and ‘safety’ is the spatial focality of stimulation.
Spatial focality = spatial extent of induced electric field in the brain
Cheap and ease of use.
However:
Objective : Examine Optimised electrode configuration and to developModulation maps that may guide anatomically and functionally targetedTCS application.
![Page 18: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/18.jpg)
Ring
Fig.2e
Fig.2c
Cortical Surface
Mag Radial Tang.
Distant Bipolar
Cortical Surface
Cortical Surface
PROOF OF CONCEPT
Datta et. al 2008
More accurate head model desired in a clinical setting…….
max
min
![Page 19: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/19.jpg)
Smoothing and segmentation algorithms of SIMPLEWARE LTD.
MRI DERIVED FINITE ELEMENT MODEL
![Page 20: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/20.jpg)
SUBDOMAIN SETTINGS
scalp
Brain
electrode
skull
Cerebrospinal fluid
![Page 21: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/21.jpg)
Meshes generated using SIMPLEWARE are imported into COMSOL
![Page 22: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/22.jpg)
Ground boundary condition
Inward current flow= Jn
All external surfaces insulated
BOUNDARY SETTINGS
![Page 23: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/23.jpg)
PHYSICS OF THE PROBLEM
SOLVER USED: conjugate gradients
TOLERANCE: 1e-8.
The electric field in a volume conductor:
.( ) 0Vσ∇ ∇ =
uniform conductivity assumption Laplacian equation
(V: potential; σ: conductivity)
![Page 24: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/24.jpg)
DISTANT BIPOLAR CONFIGURATION
Commonly used configuration is poorly focused…..
min
maxelectric field
arrows show the flow of current
![Page 25: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/25.jpg)
HOW TO PRACTICALLY IMPLEMENT A RING ELECTRODE ON THE HEAD…
- Head shape not smooth
- Impossible to maintain similar electrode-scalp impedance at all points….
![Page 26: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/26.jpg)
Advantage of using a ring configuration….
Would need more current to obtain similar efficacy…
Calculate using a FEM model…
PROPOSED CONFIGURATION
![Page 27: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/27.jpg)
4 X 1 configuration leads to significant increases in focality
4 x 1 RING CONFIGURATION
electric field
![Page 28: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/28.jpg)
E-field in brain / CSF MRI sliceCurrent Density in brain / CSF
Our models give sub-gyri/sulci specificity
Guided by the FEM model, a novel head gear was developed to position the return electrode(s) and the active electrodes appropriately based on user needs….
![Page 29: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/29.jpg)
FE CSF
![Page 30: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/30.jpg)
Summary
![Page 31: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/31.jpg)
Superficial cortical regions can be selectively targeted using a 4 x 1 system.
Spatially optimal 4×1 ring configurations were selected based on the model predictions such that the peak induced cortical electric field was comparable to standard 2 electrode (bipolar) tDCS protocols.
![Page 32: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/32.jpg)
Using Simpleware software you can
Robust and accurate models for simulation/analysis -
Explore influence of parameters on response of system(sensitivity studies); contribution of different phases, influence of assumed interfacial mechanics, …
![Page 33: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/33.jpg)
Advantages:
Accuracy
User Friendliness and very easy to use
Material properties
Coupled problems can be modelled seamlessly
Suitable for Micro-CT data
![Page 34: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/34.jpg)
ACKNOWLEDGEMENTS
COMSOL Inc., Pejman Sehatpour (NKl), Eric Wasserman (NIH).
Abhishek Data : Department of Biomedical Engg. The city college of New York, University of New York. USA.
![Page 35: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/35.jpg)
Accelerate your Success Accelerate your Success WithWith
ScanIP/ScanFE/ScanCADScanIP/ScanFE/ScanCAD
Q&AQ&A
![Page 36: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/36.jpg)
Imaged-based accuracy:Topology preservation
a. Original image, unsmoothed
b. Topology preserving smoothing
c. Non-topology preserving smoothing
a. b. c.
No loss of structures
![Page 37: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/37.jpg)
Image-based accuracy:Volume preservation
a. Original image, unsmoothed (203,238 mm3).
b. Traditional smoothed (180,605 mm3, Δvolume = -11.14%)
c. Simpleware developed (202,534 mm3, Δvolume = -0.35%)
Smooth without loss or gain of volume
a b ca
![Page 38: Image Based-Mesh Generation for realistic Simulation of ... · Simpleware Founded in December 2000 Based in Exeter, United Kingdom Global customer base World-wide reseller network](https://reader035.vdocuments.us/reader035/viewer/2022063000/5f0b579f7e708231d4300add/html5/thumbnails/38.jpg)
User defined mesh refinement
Meshes of variable element density