Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health 3D Modeling of Cervical Musculature and its Effect on Neck Injury Prevention DIVISION OF
NEURONIC ENGINEERING Defence of Doctoral Thesis Sofia Hedenstierna
Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health 3D Modeling of Cervical Musculature and its Effect on Neck Injury Prevention DIVISION OF
NEURONIC ENGINEERING Defence of Doctoral Thesis Sofia Hedenstierna
Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health With combined knowledge of medicine and engineering improve the prevention of head and neck injuries ? Division of Neuronic Engineering Neurotrauma + Mechanics
Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health Neck Injury Prevention Experimental Research and Development Davidsson et al. (1998)
Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health Neck Injury Prevention Existing numerical models of the cervical musculature Eindhoven (MADYMO)
(Van der Horst 2002) France (RADIOSS)
(Frechede et al. 2006) KTH (LS-DYNA)
(Brolin et al. 2005) Duke (LS-DYNA)
(Chancey et al. 2003) JAMA (LS-DYNA)
(Ejima et al. 2005)
The KTH FE Neck Model Intervertebral Disks and Ligaments Vertebrae Muscles Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health Numerical Modeling
Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health Solid model: Improved Boundary Condition for Injury Prediction in Cervical Column 3D geometry
Inertia forces
Compressive stiffness Output from Muscle Tissue for Muscle Injury Analysis Strain
Cross sectional forces
Strain energy Passive force
Active force Discrete model: Numerical Modeling
better understand the contribution from musculature on the stability of the head neck complex,
improve the injury prediction of the cervical spine e.g. vertebra and ligament,
enable analysis of strain in the muscle elements to predict injury in the muscle tissue. Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health Objectives Main objective: To develop a 3D finite element model of the cervical musculature using solid elements, in order to:
Introduction
Method
Geometry
Material Modeling
Evaluation
Results From Papers
Conclusions
Future Work
3D Modeling of Cervical Musculature and its Effect on Neck Injury Prevention Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health
Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health Geometry of the Cervical Musculature The FE Muscle Model Geometry created from MRI Segmented from MRI (50th percentile)
Interpolated into 3D surfaces
Anatomical guide books /morphometric literature
Neurosurgical expertise and dissection
Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health Segmented from MRI (50th percentile)
Interpolated into 3D surfaces
Positioned relative the KTH neck model in line with the literature Geometry of the Cervical Musculature The FE Muscle Model Geometry created from MRI
25 individual muscle pairs
Rigid body insertions to the vertebrae
One muscle can have multiple origins/insertions Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health Geometry of the Cervical Musculature The FE Muscle Model Geometry created from MRI
Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health Geometry of the Cervical Musculature Anterior: Hyoid, SCM Lateral: SCM, TZ Posterior: TZ, SplCap Posterior: Suboccipital
Create the geometry of the solid element muscle model and compare the kinematic response with a spring muscle model, using the same active spring elements
Introduction
Method
Geometry
Material Modeling
Evaluation
Results From Papers
Conclusions
Future Work 3D Modeling of Cervical Musculature and its Effect on Neck Injury Prevention Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health
The Active force is generated voluntarily or by reflex. It has a maximum at optimal muscle length Lopt and decreases rapidly as the muscle is shortened or extended. Force Length Passive Active Total Isometric
contraction Lopt Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health
The Passive force depends on the stiffness on the muscle tissue and increase nonlinearly with the length. Mechanical properties of muscle tissue The Total force is the sum of passive and active forces. Material response: passive stiffness and active contraction
Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health Mechanical properties of muscle tissue v=1/s 10/s 25/s [Myers et al 1995] [Davis et al 2003] Material formulations: Passive
Material formulations: Passive Nonlinear elastic Ogden Rubber Energy Potential Parameters obtained from and validated for study on the rabbit Tibialis Anterior muscle [Davis et al 2003] [Ogden 1972] Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health Mechanical properties of muscle tissue Unidirectional stress e
Material formulations: Passive Nonlinear elastic
Viscoelastic Ogden Rubber Energy Potential [Ogden 1972] Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health Mechanical properties of muscle tissue Unidirectional stress Viscoelasticity Prony Series
Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health Mechanical properties of muscle tissue Material formulations: Passive v=1/s 10/s 25/s Ogden
The Hill-type element Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health Material formulations: Active Mechanical properties of muscle tissue CE CE Active force
Damper
Passive force
fTL(Lr) Act(t) Fmax·PCSA
Peak muscle stress of 50 N/cm2 [Winters and Stark 1988] The Hill-type element Sofia Hedenstierna
Division of Neuronic Engineering, School of Technology and Health Material formulations: Active Mechanical properties of muscle tissue CE FCE= Fmax·PCSA·Act(t)·fTL(Lr) CE Active force
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