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12 projects in result set.
Are subject-specific musculoskeletal models robust to parameter identification?
- This study analyzed the sensitivity of the predictions of an MRI-based musculoskeletal model (i.e., joint angles, joint moments, muscle and joint contact forces) during walking to the unavoidable uncertainties in parameter identification, i.e., body landmark positions, maximum muscle tension and musculotendon geometry. To this aim, we created an MRI-based musculoskeletal model of the lower limbs, defined as a 7-segment, 10-degree-of-freedom articulated linkage, actuated by 84 musculotendon units. We then performed a Monte-Carlo probabilistic analysis perturbing model parameters according to their uncertainty, and solving a typical inverse dynamics and static optimization problem using 500 models that included the different sets of perturbed variable values. Model creation and gait simulations were performed by using freely available software that we developed to standardize the process of model creation, integrate with OpenSim and create probabilistic simulations of movement. | |
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Activity Percentile: 93.13 Registered: 2014-11-10 15:19 |
Normal human left ventricular myofiber stress
- Ventricular wall stress is believed to be responsible for many physical mechanisms taking place in the human heart, including ventricular remodeling, which is frequently associated with heart failure. Therefore, normalization of ventricular wall stress is the cornerstone of many existing and new treatments for heart failure. In this paper, we sought to construct reference maps of normal ventricular wall stress in humans that could be used as a target for in silico optimization studies of existing and potential new treatments for heart failure. To do so, we constructed personalized computational models of the left ventricles of five normal human subjects using magnetic resonance images and the finite element method. These models were calibrated using left ventricular volume data extracted from magnetic resonance imaging (MRI) and validated through comparison with strain measurements from tagged MRI (950 ± 170 strain comparisons/subject). The calibrated passive material parameter values were C0 = 0.115 ± 0.008 kPa and B0 = 14.4 ± 3.18; the active material parameter value was Tmax = 143 ± 11.1 kPa. These values could serve as a reference for future construction of normal human left ventricular computational models. The differences between the predicted and the measured circumferential and longitudinal strains in each subject were 3.4% ± 6.3% and 0.5% ± 5.9%, respectively. The predicted end-diastolic and end-systolic myofiber stress fields for the five subjects were 2.21 ± 0.58 kPa and 16.54 ± 4.73 kPa, respectively. Thus, these stresses could serve as targets for in silico design of heart failure treatments. | |
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Registered: 2014-06-04 18:58 |
Wrist Anatomy and Kinematics Data Collection
- <div align="justify">CT images of wrists from 90 healthy volunteers (43 males and 47 females) were acquired in various wrist positions. The outer cortical surfaces of the carpal bones, radius, and ulna in a 3D format, and each bone kinematics were calculated for each wrist position using a methodology described in the README file associated with the database. The database does not include soft tissue or the cartilage information of the wrist. Moreover, there is a MATLAB graphic user interface (GUI) available for you to observe the database. This dataset comes from four different NIH funding between 2001 and 2014.</div>
Please cite the work if you're using this database:
<div align="justify"><a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/jor.24435">Akhbari, B., Moore, D. C., Laidlaw, D. H., Akelman, E., Weiss, A-P. C., Wolfe, S. W., Crisco, J. J., 2019. Predicting Carpal Bone Kinematics using an Expanded Digital Database of Wrist Carpal Bone Anatomy and Kinematics, Journal of Orthopaedic Research. DOI:10.1002/jor.24435</a></div>
If you want the pdf version of the manuscript, please send your request on <a href="http://bit.ly/2YU2tTh">ResearchGate</a>.
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Registered: 2019-02-25 19:48 |
The Osteoporotic Virtual Physiological Human
- Nearly four million osteoporotic bone fractures cost the European health system more than 30 billion Euro per year. This figure could double by 2050. After the first fracture, the chances of having another one increase by 86%. We need to prevent osteoporotic fractures. The first step is an accurate prediction of the patient-specific risk of fracture that considers not only the
skeletal determinants but also the neuromuscular condition. The aim of VPHOP is to develop a multiscale modelling technology based on conventional diagnostic imaging methods that makes it possible, in a clinical setting, to predict for each patient the strength of his/her bones, how this strength is likely to change over time, and the probability that the he/she will overload his/her bones during daily life. With these three predictions, the evaluation of the
absolute risk of bone fracture will be much more accurate than any prediction based on
external and indirect determinants, as it is current clinical practice. These predictions will be used to: i) improve the diagnostic accuracy of the current clinical standards; ii) to provide the basis for an evidence-based prognosis with respect to the natural evolution of the disease, to pharmacological treatments, and/or to preventive interventional treatments aimed to selectively strengthen particularly weak regions of the skeleton. For patients at high risk of fracture, and for which the pharmacological treatment appears insufficient, the VPHOP system will also assist the interventional radiologist in planning the augmentation procedure.
The various modelling technologies developed during the project will be validated not only in vitro, on animal models, or against retrospective clinical outcomes, but will also be assessed in term of clinical impact and safety on small cohorts of patients enrolled at four different clinical institutions, providing the factual basis for effective clinical and industrial exploitations. | |
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Registered: 2010-03-08 08:57 |
3D visualization of spinal kinematics collected in 2D using Quantitative Fluoros
- 3D visualization of spinal kinematics collected in 2D using Quantitative Fluorosopy | |
Activity Percentile: 0.00 Registered: 2015-03-16 16:10 |
Specimen specific finite element model to study cruciate mechanics.
- This project will create a model for the anterior and posterior cruciate ligaments (ACL and PCL)from magnetic resonance imaging (MRI) images. This model will allow users to discover the stresses, strains, and displacements of the ACL and PCL that will result from varying forces applied at different positions on the knee. | |
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Registered: 2014-05-27 18:02 |
CFD analysis of Arterial flow in Thromboembolism
- To evaluate "52" dimensionless CFD numbers (akin to 'deck' of French-Playing cards):-
# Reynolds number,
# Sherwood number,
# Schimdt number,
# Rayleigh number,
# Weber number,
# Capillary number,
# Bond number,
# Froude number,
# Nusselt number,
# Peclet number (for Mass diffusivity),
# Peclet number (for Heat diffusivity),
# Prandtl number,
# Grashof number, and
# Brinkman number,
# Cavitation number,
# Stanton number,
# [Mass -Transfer] Stanton number,
# Eckert number,
# Knudsen number,
# Graetz number,
# Lewis number,
# Mach number,
# Poiseuille number,
# Rossby number,
# Strouhal number; and
# Taylor number,
# Archimedes number,
# Arrhenius number,
# Bingham number,
# Biot number,
# [Mass-Transfer] Biot number,
# Blake number,
# Bondenstein number,
# Cauchy number,
# Coefficient of Frication (dimensionless number),
# Condensation number,
# Dean number,
# Drag-coefficient (dimensionless number),
# Elasticity number,
# Etovos number,
# Euler number,
# Fourier number,
# [Mass-Transfer] Fourier number,
# Friction factor (dimensionless number),
# Galileo number,
# Colburn "j" (Heat) factor,
# Colburn "j" (Mass) factor,
# Hodgson number,
# Jakob number,
# Ohnesorge number,
# Pipeline parameter (dimensionless number),
# Power number [possibly of 3D-printed Thrombotic human heart].
Ideally, we would very much like to Extend this "Wolfram Mathematica-11 Demonstration" under the simplistic consideration of a Single "Spherical Thromb", merely beyond the Re= Reynolds number - to ALL of the "52" CFD-'deck' numbers immediately post-Plaque Fissure around the instance of "Thrombotic-Thrombolytic Equilibrium" involved in Coronary Arterial flow.
DEMO:
- Mikhail Dimitrov Mikhailov
"Flow around a Sphere at Finite Reynolds Number by Galerkin Method"
http://demonstrations.wolfram.com/FlowAroundASphereAtFiniteReynoldsNumberByGalerkinMethod/
Wolfram Demonstrations Project
Published: January 2, 2013
REFERENCES:
[0] Coronary Plaque Disruption
Erling Falk, Prediman K. Shah, Valentin Fuster
https://doi.org/10.1161/01.CIR.92.3.657
Circulation. 1995;92:657-671
Originally published August 1, 1995.
[1] Lagrangian wall shear stress structures and near-wall transport in high-Schmidt-number aneurysmal flows.
Amirhossein Arzani (a1), Alberto M. Gambaruto (a2), Guoning Chen (a3) and Shawn C. Shadden (a1)
(a1) Mechanical Engineering, University of California Berkeley, Berkeley, CA 94720, USA
(a2) Mechanical Engineering, University of Bristol, University Walk, Bristol BS8 1TR, UK
(a3) Computer Science, University of Houston, Houston, TX 77204, USA
https://doi.org/10.1017/jfm.2016.6
[2] A reduced-dimensional model for near-wall transport in cardiovascular flows.
Kirk B. Hansen* , Shawn C. Shadden*
*Department of Mechanical Engineering, University of California, Berkeley, CA, USA.
PMID: 26298313 PMCID: PMC4764478 DOI: 10.1007/s10237-015-0719-4
^WIKI:
https://en.wikipedia.org/wiki/Dimensionless_numbers_in_fluid_mechanics
$OPEN ACCESS IMAGING DATASETS:
https://grand-challenge.org/
@OUR LAB HOMEPAGE:
http://www.triindia.org/
%RESOURCES:
http://www.cfd.life/
https://cfd.direct/
+CERTIFICATIONS:
https://onlinecourses.nptel.ac.in/noc17_ee01/preview
https://onlinecourses.nptel.ac.in/noc17_ch01/preview
~Inspiration: "CAF" (Cellular Automaton Fluids: Wolfram, 1986).
http://www.stephenwolfram.com/publications/cellular-automata-complexity/pdfs/cellular-automaton-fluids-theory.pdf | |
Registered: 2017-01-23 13:42 |
The Musculoskeletal Atlas Project
- We have built an open-source software framework called the Musculoskeletal Atlas Project (MAP) for creating musculoskeletal models. The software is built with a Python plug-in architecture, to enable quick and easy development from the community. The client-side application (MAP Client) facilitates dicom and motion capture integration, registration tools, and meshing capabilities. The MAP database stores meshes from a larger population of medical imaging data, known as the Melbourne Femur Collection, which consists of 320 full body CT scans. The MAP Client uses statistical shape modelling to provide a best-match to your mocap and medical imaging data and generate surface geometry to generate an OpenSim model.
MAPClient Homepage :
http://map-client.readthedocs.io/en/latest/
MAPClient - FAI Workshop :
http://map-client-fai-workshop.readthedocs.io/en/stable/
Git Hub Repo Generic MAP plugins :
https://github.com/mapclient-plugins
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Activity Percentile: 0.00 Registered: 2012-08-15 00:07 |
FPSM - French Pediatric Shoulder Model to evaluate shoulder joint disorders
- We at LaTIM, INSERM unit 1101 in Brest, France, are conducting research on shoulder joint disorders in adults and children. Pediatric joint models are scarce in OpenSIM. Shoulder joint disorders in children are challenging as the anatomy (and biomechanics) varies by age. This project aims to develop pediatric shoulder joint model and to disseminate the modeling and geometry information to the SimTK user community.
This project started as a main thesis topic of our PhD student Ms. Asma Salhi and is built from scratch as no much modeling data or information is available for pediatric shoulder. While everyone can access and download the model files as and when made available, developers need to contact us in order to contribute to the development efforts.
This project is currently funded by Region of Brittany, France; IMT Atlantique, Brest, France, Campus France, INSERM, and CHRU de Brest. | |
Registered: 2018-06-27 13:33 |
3D Numerical Investigation of Endothelial Shear Stress in Arteries
- 3D numerical investigation of endothelial shear stress in coronary arteries. | |
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Activity Percentile: 0.00 Registered: 2015-11-30 13:34 |
Fiber Tractography for Finite-Element Modeling of Transversely Isotropic Tissues
- This project demonstrates the process for fiber tractography of complex biological tissues with transverse isotropy, such as tendon and muscle. This is important for finite element studies of these tissues, as the fiber direction must be specified in the constitutive model. This project contains code, models, and data that can be used to reproduce the results of our publication on this technique. The supplied instructional videos will enable researchers to easily and efficiently apply this method to a variety of other tissues. The software used in the fiber tractography process and demonstrated in this project is Matlab, Autodesk Inventor (free for educators), and Autodesk Simulation CFD (free for educators). Full demonstrations and process instructions can be found in the 7 videos posted at https://vimeo.com/album/3414604:
Contents:
Chapter 1: Introduction (2:35)
This video introduces the CFD fiber tractography software pipeline
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Chapter 2: Supplementary materials code, models and data (20:21)
This video shows the shared models, code, and data posted online at simtk.org/m3lab_cfd4fea.
Chapter 3: Finite element simulations (5:38)
This video shows finite element simulations using the fiber mapping process.
Chapter 4: Iliacus example walkthrough (21:38)
This video shows the step-by-step process for fiber mapping the iliacus muscle (a hip flexor).
Chapter 5: Bflh example walkthrough (12:09)
This video shows the step-by-step process for fiber mapping the biceps femoris longhead muscle (a hamstring).
Chapter 6: Autodesk Inventor segmentation (9:09)
This video shows how to do segmentation of medical images in Autodesk Inventor in order to simplify the solid model for the CFD and FEA software.
Chapter 7: Curved inlet surfaces (6:28)
This video shows how to create curved inlet surfaces for use in Autodesk Simulation CFD. | |
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Activity Percentile: 0.00 Registered: 2015-05-28 18:52 |
NMBL Image to Model Pipeline
- The NMBL Pipeline is a version of NAMIC's (www.na-mic.org) 3D Slicer, adapted to the needs of the Neuromuscular Biomechanics Lab (NMBL) at Stanford University. Slicer is an open-source software tool for performing a diverse array of medical image processing activities within one freely available, easily extensible kit. NMBL Pipeline is intended to coincide with NAMIC's Slicer, and is developed along with 3D Slicer in full collaboration with NAMIC. The differences between NMBL Pipeline and Slicer will be minimal, and probably will include the absence of some of Slicer's modules in NMBL Pipeline, and perhaps some differences in default value settings. This project will continue to be developed for use by NMBL and other members of the general Slicer user community.
I intend to use SimTK.org in exactly those ways that are intended: namely to make my software available to SimTK users and provide users with documentation, while the users are encouraged to provide feedback to me for improvements. | |
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Activity Percentile: 0.00 Registered: 2005-07-25 22:48 |