Hydrostaticpressure (kPa)

(1)

Centre for Centre for Centre for

Centre for Health Health Health Health Engineering Engineering Engineering Engineering

CNRS UMR 5146 – INSERM IFR 143

Identification of the material parameters of soft tissues in the compressed leg

Laura Dubuis, Stéphane Avril, Johan

Debayle, Pierre Badel

(2)

LaMCoS - 2010/11/17 - Stéphane AVRIL

Introduction

Context

Calf: a peripheral heart Different types of

treatments by compression Towards patient-specific compression

FE model

Geometry and meshing Model specifications Constitutive equations Identification

Identification results Results

Results results

Conclusion

Prospects

Acknowledgements

(3)

Veinous Veinous Veinous Veinous Veinous Veinous Veinous Veinous diseases diseases diseases diseases diseases diseases diseases diseases

Context

Introduction

Context

FE model

Results results

(4)

Calf: a peripheral heart

[P. Ducrozet. Booster study. PhD thesis, Université Jean Monnet, Saint Etienne, 2004]

[S. Couzan, P. Mismetti, S. Laporte, J.F. Pouget, E. Gauthier, D. Brisot, I. Quere, A. Leizorovicz. CE-Prog study.

Saint-Étienne, 2009]

Introduction

Context

FE model

Results results

Conclusion

Prospects

Acknowledgements

(5)

Different types of treatments by compression

High pressure

Low pressure Low

pressure

High pressure Conventional Conventional Conventional

Conventional compression compression compression compression (compression stockings) (1956)

Progressive compression Progressive compression Progressive compression Progressive compression (BVSport patent)

(1997)

Introduction

Context

FE model

Results results

(6)

Towards patient-specific compression

Device Device Device Device for for for for veinous veinous veinous veinous pressure pressure pressure pressure measurements measurements measurements measurements Compressionmeter Compressionmeter Compressionmeter Compressionmeter for custom compression for custom compression for custom compression for custom compression

Raises Raises Raises Raises mechanical mechanical mechanical mechanical issues: issues: issues: issues:

Pressure transmission from stockings to soft tissues?

Mechanical properties of these tissues?

Pressure field in tissues?

Introduction

Context

FE model

Results results

Conclusion

Prospects

Acknowledgements

(7)

FE model

Introduction

Context

FE model

Results results

(8)

Geometry and meshing

Exterior surface

Muscle surface

Bone surface

FE Mesh FE model:

FE model:

Introduction

Context

FE model

Results results

Conclusion

Prospects

Acknowledgements

(9)

Model specifications

Boundary Boundary Boundary Boundary conditions conditions conditions conditions

Bones clamped

Pressure applied by the stocking Laplace law: P=T/R _c

FE model:

Introduction

Context

FE model

Results results

(10)

Constitutive equations

[S. Avril, L. Bouten, L. Dubuis, S. Drapier, J-F. Pouget. Mixed Experimental and Numerical Approach for

Characterizing the Biomechanical Response of the Human Leg Under Elastic Compression. J. Biomechanical Eng. 132, 2009.]

FE model:

Neo Neo- Neo Neo - -Hookean - Hookean Hookean Hookean model model model model

MRI slice Introduction

Context

FE model

Results results

Conclusion

Prospects

Acknowledgements

(11)

Identification FE model:

FE model:

Introduction

Context

FE model

Results results

(12)

Identification FE model:

FE model:

Inverse problem: definition of the cost function

Introduction

Context

FE model

Results results

Conclusion

Prospects

Acknowledgements

(13)

Identified Identified Identified Identified constitutive constitutive constitutive constitutive parameters parameters parameters parameters

1160 1160 1160 1160 1060

1060 1060 1060 K (

K ( K (

K (kPa kPa kPa kPa))))

11.5 11.5 11.5 11.5 5

5 5 5 C

C C

C ₁₀ ₁₀ ₁₀ ₁₀ ((((kPa kPa kPa kPa))))

Muscle Muscle Muscle Muscle Fat

Fat Fat Fat

Hyperelastic

Neo Hookean model FE model:

FE model:

Identification results

Introduction

Context

FE model

Results results

(14)

FE model:

Identification results

Introduction

Context

FE model

Results results

Conclusion

Prospects

Acknowledgements

(15)

Results

Hydrostatic Hydrostatic Hydrostatic Hydrostatic pressure pressure pressure pressure

FE model:

Introduction

Context

FE model

Results results

(16)

Results

Great saphenous

Small saphenous Anterior

tibial

Posterior tibial

Fibular FE model:

FE model:

Introduction

Context

FE model

Results results

Conclusion

Prospects

Acknowledgements

(17)

y d ro s ta ti c p re s s u re ( k P a )

Results

Hydrostatic Hydrostatic Hydrostatic Hydrostatic pressure pressure pressure pressure at at at at different different different locations different locations locations locations

A p p li e d p re s s u re

F ib u la r

s te ri o r ti b ia l

te ri o r ti b ia l

ri o r ti b ia l

G re a t s a p h e n o u s

re a t s a p h e n o u s

S m a ll s a p h e n o u s

lm a ll s a p h e n o u s

1 % 3 %

6 %

3 %

0 %

FE model:

Introduction

Context

FE model

Results results

(18)

results FE model:

FE model:

Introduction

Context

FE model

Results results

Conclusion

Prospects

Acknowledgements

Hydrostatic Hydrostatic Hydrostatic Hydrostatic pressure pressure pressure pressure at at at at different different different heights different heights heights heights

(19)

Conclusion

Introduction

Context

FE model

Results results

(20)

Hydrostaticpressure (kPa)

Centre for Centre for Centre for

Centre for Health Health Health Health Engineering Engineering Engineering Engineering

CNRS UMR 5146 – INSERM IFR 143

Identification of the material parameters of soft tissues in the compressed leg

Laura Dubuis, Stéphane Avril, Johan

Debayle, Pierre Badel

Introduction

Introduction

FE model

Conclusion

Veinous Veinous Veinous Veinous Veinous Veinous Veinous Veinous diseases diseases diseases diseases diseases diseases diseases diseases

Context

Introduction

FE model

Calf: a peripheral heart

[P. Ducrozet. Booster study. PhD thesis, Université Jean Monnet, Saint Etienne, 2004]

[S. Couzan, P. Mismetti, S. Laporte, J.F. Pouget, E. Gauthier, D. Brisot, I. Quere, A. Leizorovicz. CE-Prog study.

Saint-Étienne, 2009]

Introduction

FE model

Conclusion

Different types of treatments by compression

High pressure

Low pressure Low

pressure

High pressure Conventional Conventional Conventional

Conventional compression compression compression compression (compression stockings) (1956)

Progressive compression Progressive compression Progressive compression Progressive compression (BVSport patent)

(1997)

Introduction

FE model

Towards patient-specific compression

Raises Raises Raises Raises mechanical mechanical mechanical mechanical issues: issues: issues: issues:

Pressure transmission from stockings to soft tissues?

Mechanical properties of these tissues?

Pressure field in tissues?

Introduction

FE model

Conclusion

FE model

Introduction

FE model

Geometry and meshing

Exterior surface

Muscle surface

Bone surface

FE Mesh FE model:

FE model:

FE model:

FE model:

Introduction

FE model

Conclusion

Model specifications

Boundary Boundary Boundary Boundary conditions conditions conditions conditions

Bones clamped

Pressure applied by the stocking Laplace law: P=T/R c

FE model:

FE model:

FE model:

FE model:

Introduction

FE model

Constitutive equations

[S. Avril, L. Bouten, L. Dubuis, S. Drapier, J-F. Pouget. Mixed Experimental and Numerical Approach for

Characterizing the Biomechanical Response of the Human Leg Under Elastic Compression. J. Biomechanical Eng. 132, 2009.]

FE model:

FE model:

FE model:

FE model:

Neo Neo- Neo Neo - -Hookean - Hookean Hookean Hookean model model model model

MRI slice Introduction

FE model

Conclusion

Identification FE model:

FE model:

FE model:

FE model:

Introduction

Pressure applied by the stocking Laplace law: P=T/R _c

C ₁₀ ₁₀ ₁₀ ₁₀ ((((kPa kPa kPa kPa))))