MRIBased Human Ventricle Model for Surgery Optimization

Send This

Download

Comment

Favourite

more

Rating :

Rate It:

Embed :

Post a comment

Post Comment on Twitter Post Comment on SlideWorld

Comments:

Subscribe to follow-up comments

Notes

Hide Notes

Slide 1 :

Two-Layer Passive/Active Anisotropic FSI Models with Fiber Orientation: MRI-Based Patient-Specific Right Ventricle Models for Pulmonary Valve Insertion Surgery Design Dalin Tang, Ph.D. Mathematical Sciences Dept., Worcester Polytechnic Institute Chun Yang, M.S.Mathematics Dept., Beijing Normal University, Beijing, China Pedro J. del Nido, M.D., Tal Geva, M.D. Harvard Medical School, Department of Cardiac SurgeryBoston Children’s Hospital, Boston, MA 02115 This paper was published in Journal of Molecular & Cellular Biomechanics Vol. 4, No. 3, pp. 159-176, 2007. Acknowledgement: This research was supported in part by NIH – HL63095 (PJdN), NIH-NHLBI 5P50 HL074734 (Geva).

Slide :

Slide 3 :

MRI-Based 3D RV Geometry Re-Construction Tricuspid valve Pulmonary valve (a) A human heart (b) Segmented RV MRI contour plots (c) Computational Mesh (d) RV/LV from MRI RV LV (e) Re-constructed RV/ LV geometry RV LV Patch (f) RV with Patch

Slide 4 :

RV LV LV RV MRI-Based 3D RV Geometry Re-Construction(Pre-Operation MRI) Patch& Scar RV LV

Slide 5 :

RV cardiac function assessment Stroke Volume (SV) RV End Diastolic (maximal) Volume – RV End Systolic (minimal) Volume, Ejection Fraction (EF) [RV end diastolic volume (RVEDV) - RV end systolic volume (RVESV)]/RVEDV, End Points

Slide 6 :

A RV/LV Combination FSI Model for Surgical Design and Clinical Use Fluid: Newtonian, 3D, Unsteady, Viscous, Incompressible Solid: Hyperelastic, Anisotropic, Nonlinear,Mooney-Rivlin Model Fluid-Structure Interactions, Pressure Conditions Validation: Pre-operative RV Volume Post-operative RV Volume

Slide 7 :

Important Features of the RV/LV Model with FSI Anisotropic Material Properties Multi-Layer Construction with Fiber Orientation Active Contraction

Slide 8 :

The Fluid Model

Slide 9 :

? vi,tt = sij,j , i,j=1,2,3; sum over j, ?ij = ( vi,j + vj,i )/2, i, j=1,2,3, sij ? nj|out_wall =0, srij ? nj|interface = ssij ? nj|interface , W= c1(I1–3) +c2(I2–3)+D1[exp(D2(I1–3))–1], I1 = ? Cii , I2 = ½ [I12 - Cij Cij], sij = (?W/??ij + ?W/??ji )/2 The Solid Isotropic Model

Slide 10 :

Isotropic Scar Patch AnisotropicTff, Tcc Stretch Ratio Stretch Ratio *: Tff –end of systole ?: Tff –end of diastole (a) Stress-stretch curves for passive models (b) Active/p stresses from a dog model (c) Stress-stretch curves from proposed patient- specific model matching CMR data o: Tcc- end of systole x: Tcc – end of diastole Material Stress-Stretch curves from Isotropic/Anisotropic Passive/Active models

Slide 11 :

Pressure Conditions and Material Properties

Slide 12 :

Use Cardiac MRI to Adjust Material Parameters and Pressure Conditions to Fit CMR RV Volume Curve (d) Computational RV Volume Compared with CMR Data Showing Good Agreement ComputationalRV Volume CMR Data

Slide 13 :

Two-Layer Model with Fiber Orientations

Slide 14 :

Front Back Healthy Diseased Fiber Orientation of the Human Heart, Out-Layer

Slide :

Slide 17 :

Posterior (back) view Fiber Orientation of the Human Heart

Slide :

Slide 19 :

Min Universal Scale Max LV RV RV (a) Cut Surface-1, Left Part (b) Right Portion Cut-Surface for Presentation of 3D Results

Slide 20 :

Stress/Strain Distributions in RV with a Patch

Slide 21 :

ActiveModel Max=1.042 Min=-2.38KPa Max=796.1KPa (a) Cut Position (Stress-P1) (c) Strain-P1, at Pmax (b) Stress-P1, at Pmax Min= -2.38 KPa Max=796.1KPa Min=0.00051 Max=359.8 KPa Max=898.1 KPa Max=1.225 (a) Stress-P1, Isotropic (c) Strain-P1, Isotropic (b) Stress-P1, Anisotropic Max Universal Scale Min PassiveModel The maximum Stress-P1 values from passive and active anisotropic models were 149.6% and 121.2% higher than that from the passive isotropic model, respectively. Comparison: Passive Isotropic/Anisotropic and Active Anisotropic Models (at Pmax)

Slide 22 :

Min Universal Scale Max (a) t=0.1s, beginning of filling (c) t=0.37s, beginning of ejection inlet closed, outlet just opened (d) t=0.39s, ejection continues. Outlet (closed) Inlet (open) (b) t=0.35s, just before end of filling (diastole) Outlet (closed) Inlet (open) Max=5.69 Max=17.83 Min=5.59 Min=17.81 Max=18.80 Max=18.35 Min=17.90 Min=18.07 Unit: mmHg Velocity and Pressure Plots at Different Phases Showing Interesting Patterns

Slide 23 :

Patch Design and Optimization Process

Slide 24 :

RV Stroke Volume and Ejection Fraction Three Model Comparisons

Slide 25 :

(a) CMR-Measured Average Flow Rate at the Pulmonary Valve (b) CMR-Measured Accumulated Total Out- Flow at the Pulmonary Valve Flow-Rate > 0, out-flow Flow-Rate > 0, Leaking Back In-Flow(regurgitation) Out-Flow Out-Flow Time Flow Rate Volume Pulmonary Regurgitation(Valve Leaking)

Slide 26 :

RV Stroke Volume and Ejection Fraction Three Model Comparisons

Slide 27 :

Strain-P1 on Three Models and Tracking Points (c) Patch Model 2. X1 X2 X3 X4 X5 X6 X1 X2 X3 X4 X5 X1 X2 X3 X4 X5 . . . . (a) Pre-op (Large Patch) Model. (b) Patch Model 1.

Slide :

Slide 29 :

Key Features of our Modeling Approach First step to introduce fluid-structure-interactions into patient-specific RV/LV/Patch models Aimed for computer-aided surgical planning and real clinical application (quick turn-around time) Based on clinically-available patient-specific data (morphology, flow, pressure) Verifiable end-points for RV remodeling surgery outcome measures (EF)

Slide 30 :

Conclusions The RV/LV combination model with fluid-structure interactions provides verifiable stroke volume and ejection fraction calculations which can provide rich information for computer-aided surgery planning. RV/LV interactions, valve mechanics, active tension for contraction, pulmonary regurgitation, tissue engineering, and direct mechanical measurements of tissue material properties can be added for improved accuracy, with added modeling and computing cost.

ADVERSE CEREBRAL OUT...

Genital Human Papill...

Human Sexuality

Animal models of anx...

Predictors of ambula...

Towards a new model ...

Free Powerpoint Templates

	DalinTang 5 Years ago.



505 Views, 0 favourite
PowerPoint Presentation on MRI-Based Human Ventricle Model for Surgery Optimization or PowerPoint P more PowerPoint Presentation on MRI-Based Human Ventricle Model for Surgery Optimization or PowerPoint Presentation on Two-Layer Passive/Active Anisotropic FSI Models with Fiber Orientation: MRI-Based Patient-Specific Right Ventricle Models for Pulmonary Valve Insertion Surgery Design less
More By User Flag as inappropriate Select your reason for flagging this presentation as inappropriate. If needed, use the feedback form to let us know more details. Cancel