scholarly journals Mitral valve finite-element modelling from ultrasound data: a pilot study for a new approach to understand mitral function and clinical scenarios

2008 ◽  
Vol 366 (1879) ◽  
pp. 3411-3434 ◽  
Author(s):  
Emiliano Votta ◽  
Enrico Caiani ◽  
Federico Veronesi ◽  
Monica Soncini ◽  
Franco Maria Montevecchi ◽  
...  
Keyword(s):  
Finite Element ◽  
Mitral Valve ◽  
Computational Modelling ◽  
Element Model ◽  
Normal Function ◽  
Patient Specific ◽  
Healthy Human ◽  
Muscle Dynamics ◽  
Clinical Scenarios

In the current scientific literature, particular attention is dedicated to the study of the mitral valve and to comprehension of the mechanisms that lead to its normal function, as well as those that trigger possible pathological conditions. One of the adopted approaches consists of computational modelling, which allows quantitative analysis of the mechanical behaviour of the valve by means of continuum mechanics theory and numerical techniques. However, none of the currently available models realistically accounts for all of the aspects that characterize the function of the mitral valve. Here, a new computational model of the mitral valve has been developed from in vivo data, as a first step towards the development of patient-specific models for the evaluation of annuloplasty procedures. A structural finite-element model of the mitral valve has been developed to account for all of the main valvular substructures. In particular, it includes the real geometry and the movement of the annulus and papillary muscles, reconstructed from four-dimensional ultrasound data from a healthy human subject, and a realistic description of the complex mechanical properties of mitral tissues. Preliminary simulations allowed mitral valve closure to be realistically mimicked and the role of annulus and papillary muscle dynamics to be quantified.

scholarly journals Evaluation of a modified Cheatham-Platinum stent for the treatment of aortic coarctation by finite element modelling

2018 ◽  
Vol 7 ◽  
pp. 204800401877395 ◽  
Author(s):  
Barbara EU Burkhardt ◽  
Nicholas Byrne ◽  
Marí Nieves Velasco Forte ◽  
Francesco Iannaccone ◽  
Matthieu De Beule ◽  
...  
Keyword(s):  
Finite Element ◽  
Aortic Coarctation ◽  
Computational Models ◽  
Three Dimensional ◽  
Computational Modelling ◽  
Patient Specific ◽  
Stent Design ◽  
Initial Length ◽  
Element Analysis

Objectives Stent implantation for the treatment of aortic coarctation has become a standard approach for the management of older children and adults. Criteria for optimal stent design and construction remain undefined. This study used computational modelling to compare the performance of two generations of the Cheatham-Platinum stent (NuMED, Hopkinton, NY, USA) deployed in aortic coarctation using finite element analysis. Design Three-dimensional models of both stents, reverse engineered from microCT scans, were implanted in the aortic model of one representative patient. They were virtually expanded in the vessel with a 16 mm balloon and a pressure of 2 atm. Results The conventional stent foreshortened to 96.5% of its initial length, whereas the new stent to 99.2% of its initial length. Diameters in 15 slices across the conventional stent were 11.6–15 mm (median 14.2 mm) and slightly higher across the new stent: 10.7–15.3 mm (median 14.5 mm) (p= 0.021). Apposition to the vessel wall was similar: conventional stent 31.1% and new stent 28.6% of total stent area. Conclusions The new design Cheatham-Platinum stent showed similar deployment results compared to the conventional design. The new stent design showed slightly higher expansion, using the same delivery balloon. Patient-specific computational models can be used for virtual implantation of new aortic stents and promise to inform subsequent in vivo trials.

Validate Mandible Finite Element Model under Removable Partial Denture (RPD) with In Vivo Pressure Measurement

2014 ◽  
Vol 553 ◽  
pp. 322-326 ◽  
Author(s):  
Hanako Suenaga ◽  
Jun Ning Chen ◽  
Wei Li ◽  
Keiichiro Yamaguchi ◽  
Keiichi Sasaki ◽  
...  
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Patient Specific ◽  
Fe Model ◽  
Removable Partial Denture ◽  
Partial Denture ◽  
Element Simulation ◽  
Clinical Measurements

This study aims to analyze the functional contact pressure induced by Removable Partial Denture (RPD) by using a 3D finite element (FE) model constructed based on patient specific CT scans. This model was validated against the in vivo test results. The outcomes demonstrate that the finite element simulation has the capability of quantifying localized stress distribution in a complicated denture-mucosa contact problem, with a reasonable matching to clinical measurements of occlusal force and pressure distribution. The methodology is of considerable clinical implication to improve the long term outcomes of the denture treatment.

Patient-Specific Finite Element Modeling of Mitral Valve Dynamic Deformation

2012 ◽  
Author(s):  
Qian Wang ◽  
Wei Sun
Keyword(s):  
Finite Element ◽  
Mitral Valve ◽  
Left Ventricle ◽  
Dynamic Deformation ◽  
Patient Specific ◽  
Stress And Strain ◽  
Prosthetic Devices ◽  
In Vivo Experiments ◽  
Normal Mitral Valve

Mitral valve is a two-leaflet valve that is located between the left atrium and the left ventricle of the heart. In order to successfully replace or repair mitral valve and develop effective prosthetic devices, it is critical to understand the in vivo mechanics of the normal mitral valve. Although research has been conducted to investigate animal mitral valve strains by in vivo experiments, it is still very challenging to obtain accurate in vivo stress and strain information of the human mitral valve.

scholarly journals Modelling and simulation of mitral valve for transapical repair applications

2019 ◽  
Vol 24 (4) ◽  
Author(s):  
Gediminas Gaidulis ◽  
Matteo Selmi ◽  
Diana Diana Zakarkaitė ◽  
Audrius Aidietis ◽  
Rimantas Kačianauskas
Keyword(s):  
Mitral Valve ◽  
Real Life ◽  
Computational Modelling ◽  
Element Model ◽  
Time Frame ◽  
Quantitative Information ◽  
Nonlinear Material ◽  
Patient Specific ◽  
Chordae Tendineae ◽  
Invasive Approach

Development and application of the numerical model for the simulation of human heart mitral valve (MV) transapical repair is presented. Transapical repair with neochordae implantation is a novel surgical technique allowing beating-heart correction of mitral regurgitation caused by chordae tendineae rupture through a minimally-invasive approach. In the present study, the structural finite element model of the MV decoupled from the blood flow is considered. It comprises two leaflets and chordae tendineae described by nonlinear material model. Geometry of the model and kinematic boundary conditions for fixed points of MV annulus, papillary muscles, and left ventricle apex are defined by patient-specific data. Decoupled behavior of blood is specified by the time-dependent physiologic transvalvular pressure. Personalized computational modelling strategy is applied to perform virtual transapical MV repair by positioning neochordae following the real-life surgery procedure executed by surgeons. A transient analysis in time frame between end-diastole and peak systole is conducted to evaluate post-repair MV function. Computational MV simulation and modelling results provide quantitative information about the neochordae contribution to the MV function improvement and present practical value for the surgical planning of transapical MV repair.

scholarly journals Material properties of the ovine mitral valve anterior leaflet in vivo from inverse finite element analysis

2008 ◽  
Vol 295 (3) ◽  
pp. H1141-H1149 ◽  
Author(s):  
Gaurav Krishnamurthy ◽  
Daniel B. Ennis ◽  
Akinobu Itoh ◽  
Wolfgang Bothe ◽  
Julia C. Swanson ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Mitral Valve ◽  
Material Properties ◽  
Element Model ◽  
Left Ventricular ◽  
Element Analysis ◽  
Inverse Finite Element Analysis

We measured leaflet displacements and used inverse finite-element analysis to define, for the first time, the material properties of mitral valve (MV) leaflets in vivo. Sixteen miniature radiopaque markers were sewn to the MV annulus, 16 to the anterior MV leaflet, and 1 on each papillary muscle tip in 17 sheep. Four-dimensional coordinates were obtained from biplane videofluoroscopic marker images (60 frames/s) during three complete cardiac cycles. A finite-element model of the anterior MV leaflet was developed using marker coordinates at the end of isovolumic relaxation (IVR; when the pressure difference across the valve is ∼0), as the minimum stress reference state. Leaflet displacements were simulated during IVR using measured left ventricular and atrial pressures. The leaflet shear modulus ( Gcirc-rad) and elastic moduli in both the commisure-commisure ( Ecirc) and radial ( Erad) directions were obtained using the method of feasible directions to minimize the difference between simulated and measured displacements. Group mean (±SD) values (17 animals, 3 heartbeats each, i.e., 51 cardiac cycles) were as follows: Gcirc-rad= 121 ± 22 N/mm2, Ecirc= 43 ± 18 N/mm2, and Erad= 11 ± 3 N/mm2( Ecirc> Erad, P < 0.01). These values, much greater than those previously reported from in vitro studies, may result from activated neurally controlled contractile tissue within the leaflet that is inactive in excised tissues. This could have important implications, not only to our understanding of mitral valve physiology in the beating heart but for providing additional information to aid the development of more durable tissue-engineered bioprosthetic valves.

scholarly journals Influence of Annular Dynamics and Material Behavior in Finite Element Analysis of Barlow’s Mitral Valve Disease

2021 ◽  
Author(s):  
Hans Martin Aguilera ◽  
Stig Urheim ◽  
Bjørn Skallerud ◽  
Victorien Prot
Keyword(s):  
Finite Element ◽  
Mitral Valve ◽  
Mitral Regurgitation ◽  
Boundary Conditions ◽  
Material Properties ◽  
Material Behavior ◽  
Patient Specific ◽  
Healthy Human ◽  
Barlow’S Disease ◽  
Annular Dilation

AbstractBarlow’s disease affects the entire mitral valve apparatus, by altering several of the fundamental mechanisms in the mitral valve which ensures unidirectional blood flow between the left atrium and the left ventricle. In this paper, a finite element model of a patient diagnosed with Barlow’s disease with patient-specific geometry and boundary conditions is presented. The geometry and boundary conditions are extracted from the echocardiographic assessment of the patient prior to surgery. Material properties representing myxomatous, healthy human and animal mitral valves are implemented and computed response are compared with each other and the echocardiographic images of the patient. This study shows that the annular dilation observed in Barlow’s patients controls several aspects of the mitral valve behavior during ventricular systole. The coaptation of the leaflets is observed to be highly dependent on annular dilation, and the coaptation area reduces rapidly at the onset of mitral regurgitation. Furthermore, the leaflet material implementation is important to predict lack of closure in the FE model correctly. It was observed that using healthy human material parameters in the Barlow’s diseased FE geometry gave severe lack of closure from the onset of mitral regurgitation, while myxomatous material properties showed a more physiological leakage.

scholarly journals Predicting calvarial morphology in sagittal craniosynostosis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Oyvind Malde ◽  
Connor Cross ◽  
Chien L. Lim ◽  
Arsalan Marghoub ◽  
Michael L. Cunningham ◽  
...  
Keyword(s):  
Finite Element ◽  
Input Parameter ◽  
Surgical Techniques ◽  
Element Model ◽  
Specific Model ◽  
Patient Specific ◽  
Sagittal Craniosynostosis ◽  
Sensitivity Tests ◽  
Ct Data

AbstractEarly fusion of the sagittal suture is a clinical condition called, sagittal craniosynostosis. Calvarial reconstruction is the most common treatment option for this condition with a range of techniques being developed by different groups. Computer simulations have a huge potential to predict the calvarial growth and optimise the management of this condition. However, these models need to be validated. The aim of this study was to develop a validated patient-specific finite element model of a sagittal craniosynostosis. Here, the finite element method was used to predict the calvarial morphology of a patient based on its preoperative morphology and the planned surgical techniques. A series of sensitivity tests and hypothetical models were carried out and developed to understand the effect of various input parameters on the result. Sensitivity tests highlighted that the models are sensitive to the choice of input parameter. The hypothetical models highlighted the potential of the approach in testing different reconstruction techniques. The patient-specific model highlighted that a comparable pattern of calvarial morphology to the follow up CT data could be obtained. This study forms the foundation for further studies to use the approach described here to optimise the management of sagittal craniosynostosis.

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