Electrophysiology Subject Specific Models
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Transcript of Electrophysiology Subject Specific Models
Electrophysiology Subject Specific Models
Darrell SwensonScientific Computing and Imaging (SCI) Institute
Cardiovascular Research and Training Institute (CVRTI)Department of Bioengineering
Dr. Rob MacLeod
Cardiac Ischemia• Hearts are electrical organs
Electrical current causes heart contraction
Most heart failures are electrical ECG’s show hearts electrical activity
• Coronary Arteries supply blood to the heart. Coronary blood flow provides the
needed nutrients and ions Conduction rate is dependent on blood
flow.
• Hearts are electrical organs Electrical current causes heart
contraction Most heart failures are electrical ECG’s show hearts electrical activity
• Coronary Arteries supply blood to the heart. Coronary blood flow provides the
needed nutrients and ions Conduction rate is dependent on blood
flow.
Cardiac Ischemia• Ischemia is the lack of blood flow
The lack of blood flow changes the conductance.
Changes in conductance alter the activation wave.
This often leads to heart failure These changes can be detected with an
ECG
• ECGs are insufficient to detect a large percentage of ischemia. Comparable ischemic regions produce
dramatically different ECG signals. The cause could be Individual structure
variability.
• Ischemia is the lack of blood flow The lack of blood flow changes the
conductance. Changes in conductance alter the
activation wave. This often leads to heart failure These changes can be detected with an
ECG
• ECGs are insufficient to detect a large percentage of ischemia. Comparable ischemic regions produce
dramatically different ECG signals. The cause could be Individual structure
variability.
Subject Specific Modeling
Subject Specific Geometry• Shape of heart • Shape and time point of the
ischemic region• Fiber orientation for
anisotropic conduction
Subject Specific Geometry• Shape of heart • Shape and time point of the
ischemic region• Fiber orientation for
anisotropic conduction
Problem Specific Models• Dynamic ischemic zone that
changes based on experimental data.
• Adaptive meshing based on fiber directions
• Variable myocardial wall thickness
Problem Specific Models• Dynamic ischemic zone that
changes based on experimental data.
• Adaptive meshing based on fiber directions
• Variable myocardial wall thickness
MRISegmentation Surface Meshing 3D Meshing DTI Surface Potentials
MRI• Small animal
imaging facility• 7 tesla scanner• High resolution and
DTI scans• Gd markers used
for registration
MRI• Small animal
imaging facility• 7 tesla scanner• High resolution and
DTI scans• Gd markers used
for registrationQuickTime™ and a
decompressorare needed to see this picture.
MRISegmentation Surfacing Meshing DTI Surface Potentials
QuickTime™ and a decompressor
are needed to see this picture.
QuickTime™ and ampeg4 decompressor
are needed to see this picture.
MRISegmentation
DTI Surface Potentials
Segmentation• Seg3D• Segment
myocardium and ischemic region
• Each segmentation requires a small amount of manual editing
Segmentation• Seg3D• Segment
myocardium and ischemic region
• Each segmentation requires a small amount of manual editing
QuickTime™ and a decompressor
are needed to see this picture.
Surface Meshing 3D Meshing
MRI Segmentation DTI Surface Potentials
Marching Cubes• SCIRun
implementation• Smoothed with
fairmesh algorithm• ~400,000 tris
elements• Very detailed
Particle System• Uses tetgen for
surface• Not currently in
SCIRun• Very detailed
Marching Cubes• SCIRun
implementation• Smoothed with
fairmesh algorithm• ~400,000 tris
elements• Very detailed
Particle System• Uses tetgen for
surface• Not currently in
SCIRun• Very detailed
Surface Meshing 3D Meshing
QuickTime™ and ampeg4 decompressor
are needed to see this picture.
MRI Segmentation DTI Surface PotentialsSurface Meshing 3D Meshing
MRI Segmentation DTI Surface Potentials
Meshing• 1,400,000
Elements• Tetgen used for
both marching cubes and particle system surfaces
Meshing• 1,400,000
Elements• Tetgen used for
both marching cubes and particle system surfaces
Surface Meshing 3D Meshing
MRI Segmentation DTI Surface PotentialsSurface Meshing 3D Meshing
MRI SegmentationDTI
Surface Potentials
Fiber Direction• Diffusion tensor
imaging (DTI)• Anisotropic
properties• Tensor
interpolation
Fiber Direction• Diffusion tensor
imaging (DTI)• Anisotropic
properties• Tensor
interpolation
Surface Meshing 3D Meshing
MRI Segmentation DTISurface Potentials
Ischemic Model• Bidomain model• Interactively
adaptable ischemic zone
• Segmented ischemic zones
• Correlates to experimental results
Ischemic Model• Bidomain model• Interactively
adaptable ischemic zone
• Segmented ischemic zones
• Correlates to experimental results
Surface Meshing 3D Meshing
MRI Segmentation DTISurface Potentials
Ischemic Model• Bidomain model• Interactively move
ischemic zone• Segment ischemic
zones• Correlate to lab
results
Ischemic Model• Bidomain model• Interactively move
ischemic zone• Segment ischemic
zones• Correlate to lab
results
QuickTime™ and ampeg4 decompressor
are needed to see this picture.
3D MeshingSurface Meshing
Thanks!