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intervertebral-discs
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Total 30 records
An Investigation on Neck Injury Due to Head Impact in Road Accidents Considering Hyperviscoelastic Properties of Soft Tissues
, M.Sc. Thesis Sharif University of Technology ; Ahmadian, Mohammad Taghi (Supervisor)
Abstract
Neck fracture caused by impacts on the head and neck during road accidents annually imposes a great cost to the people hospitals and the economy of country. Most of these accidents, regardless of cartilaginous injury causes sudden pressure to the spinal cord so it seems necessary to understand the biomechanical response of the neck and the mechanism of injury to reduce costs. Many computational models related to the neck injury have been developed recently. The aim of this project is to investigate the effect of frontal and rear impacts to the head and neck during road accidents. There are many researches have used elastic property for tissues but a little portion of research in this field...
Transient Diffusion of Drugs into the Intervertebral Disc using Finite Element Method
, M.Sc. Thesis Sharif University of Technology ; Parnianpour, Mohammad (Supervisor) ; Hoviattalab, Maryam (Supervisor) ; Shirazi Adl, Abolfazl (Co-Advisor)
Abstract
In this study, transient diffusion of drug into the intervertebral disc is considered. The amount of Diffused drug from the blood into the intervertebral disc of dog is measured and concentration of drug is calculated for each region of the intervertebral disc including nucleus pulpous, inner annulus fibroses and outer annulus fibroses. Using finite element method, it is shown that the amount of drug diffusion into the intervertebral disc is affected by some parameters such as the type of drug, dose if drug and endplate calcification. This research is done in two parts: In first part, diffusion of drug (sulphate) into the dog intervertebral disc is investigated to compare the obtained...
Biomechanical Modeling of Flexible-bar and Investigating of Muscle Forces and Compression Forces on Discs in Lumbar Region During of Rehabilitation Exercises
, M.Sc. Thesis Sharif University of Technology ; Parnianpour, Mohammad (Supervisor) ; Asghari, Mohsen (Supervisor)
Abstract
A single-degree-of-freedom model is considered for flexible exercise bars based on the lumped-element approach. By considering the side segment of a flexible exercise bar as a cantilever beam with an equivalent mass at the free end, its free-vibration response and forced one under excitation of the grip of the flexible bar is written parametrically. Some experiments are performed on a specific flexible bar to obtain numerical values for the parameters in the model to have it quantitatively known. In the next step, simulation of the model results in the response of the flexible bar under a considered excitation. The response is imported into a multi-segment musculoskeletal software, AnyBody,...
Development and Validation of Biomechanical Model for Calculation of Moment into the Intervertebral L5-S1 Disc and the amount of NIOSH Permissible Limit Load During Lifting Activity
, M.Sc. Thesis Sharif University of Technology ; Parnianpor, Mohammad (Supervisor) ; Narimani, Roya (Supervisor)
Abstract
Lifting is considered a major risk to people's health in life, particularly to the workers. Appropriate wearable tools for measuring the individual’s kinematic and kinetic movement are required for examining and analyzing the lifting activity to prevent injury in the workplace. Different wearable systems have been developed to calculate the force applied on the foot sole to analyze movement in various areas of gait analysis, occupational biomechanics, sports, and other areas. The accuracy and precision of these systems need to be tested before application in any of these areas. In this study, 3 subjects performed five different activities of symmetrical lifting by placing Pedar insoles in...
Poly (Vinyl Alcohol) Hydrogel/Nano-diamond as a Replacement for the Nucleus Pulposus
, M.Sc. Thesis Sharif University of Technology ; Frounchi, Masoud (Supervisor) ; Dadbin, Susan (Supervisor)
Abstract
The nucleus pulposus, which is a part of intervertebral disc, is normally hydrated and gel-like to maintain normal biomechanical functions of the disc through intradiscal pressures. In a degenerated disc, however, water content of nucleus is significantly reduced, resulting in an abnormal stress state of the annulus. Surgical interventions cannot restore the biomedical function to vertebral segment. One approach to restore the normal biomechanics of an intervertebral disc is to replace the nucleus with a prosthetic material which leads to a restoration of the behavior of the disc. The mechanical behavior of poly(vinyl alcohol) and nanodiamond hydrogel may provide a material suitable for...
SVD analysis of dynamic properties for fatigue loaded intervertebral disc
, Article 2011 1st Middle East Conference on Biomedical Engineering, MECBME 2011, 21 February 2011 through 24 February 2011, Sharjah ; 2011 , Pages 32-36 ; 9781424470006 (ISBN) ; Malik, A. S ; Wang, J. L ; Parnianpour, M ; Sharif University of Technology
2011
Abstract
This paper uses singular value decomposition (SVD) for studying the dynamic properties of fatigue-loaded intervertebral disc. Previously, this problem had been addressed using mathematical models of using mass, spring and damper or based on poroelastic theory. This paper utilizes the signal processing approach and attempts to describe SVD based feature that can be an indicator for change in behavioral performance of the intervertebral disc warning the occurrence of temporary or permanent change in the structure or abnormality in behavior. The results are encouraging; however, further validation is required with more data
A novel coupled musculoskeletal finite element model of the spine – Critical evaluation of trunk models in some tasks
, Article Journal of Biomechanics ; Volume 119 , 2021 ; 00219290 (ISSN) ; Arjmand, N ; Shirazi Adl, A ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Spine musculoskeletal (MS) models make simplifying assumptions on the intervertebral joint degrees-of-freedom (rotational and/or translational), representation (spherical or beam-like joints), and properties (linear or nonlinear). They also generally neglect the realistic structure of the joints with disc nuclei/annuli, facets, and ligaments. We aim to develop a novel MS model where trunk muscles are incorporated into a detailed finite element (FE) model of the ligamentous T12-S1 spine thus constructing a gold standard coupled MS-FE model. Model predictions are compared under some tasks with those of our earlier spherical joints, beam joints, and hybrid (uncoupled) MS-FE models. The coupled...
Material property identification of artificial degenerated intervertebral disc models - comparison of inverse poroelastic finite element analysis with biphasic closed form solution
, Article Journal of Mechanics ; Volume 29, Issue 4 , 2013 , Pages 589-597 ; 17277191 (ISSN) ; Hsu, Y. C ; Haghpanahi, M ; Parnianpour, M ; Wang, J. L ; Sharif University of Technology
2013
Abstract
ABSTRACT Disc rheological parameters regulate the mechanical and biological function of intervertebral disc. The knowledge of effects of degeneration on disc rheology can be beneficial for the design of new disc implants or therapy. We developed two material property identification protocols, i.e., inverse poroelas-tic finite element analysis, and biphasic closed form solution. These protocols were used to find the material properties of intact, moderate and severe degenerated porcine discs. Comparing these two computational protocols for intact and artificial degenerated discs showed they are valid in defining bi-phasic/poroelastic properties. We found that enzymatic agent disrupts the...
A meta-model analysis of a finite element simulation for defining poroelastic properties of intervertebral discs
, Article Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine ; Volume 227, Issue 6 , 2013 , Pages 672-682 ; 09544119 (ISSN) ; Hsu, Y. C ; Haghpanahi, M ; Parnianpour, M ; Wang, J. L ; Sharif University of Technology
2013
Abstract
Finite element analysis is an effective tool to evaluate the material properties of living tissue. For an interactive optimization procedure, the finite element analysis usually needs many simulations to reach a reasonable solution. The metamodel analysis of finite element simulation can be used to reduce the computation of a structure with complex geometry or a material with composite constitutive equations. The intervertebral disc is a complex, heterogeneous, and hydrated porous structure. A poroelastic finite element model can be used to observe the fluid transferring, pressure deviation, and other properties within the disc. Defining reasonable poroelastic material properties of the...
Dynamic responses of intervertebral disc during static creep and dynamic cyclic loading: A parametric Poroelastic finite element analysis
, Article Biomedical Engineering - Applications, Basis and Communications ; Volume 25, Issue 1 , 2013 ; 10162372 (ISSN) ; Haghpanahi, M ; Parnianpour, M ; Wang, J. L ; Sharif University of Technology
2013
Abstract
Low back pain is a common reason for activity limitation in people younger than 45 years old, and was proved to be associated with heavy physical works, repetitive lifting, impact, stationary work postures and vibrations. The study of load transferring and the loading condition encountered in spinal column can be simulated by finite element models. The intervertebral disc is a structure composed of a porous material. Many physical models were developed to simulate this phenomenon. The confounding effects of poroelastic properties and loading conditions on disc mechanical responses are, nevertheless, not cleared yet. The objective of this study was to develop an axisymmetric poroelastic...
A poroelastic finite element model to describe the time-dependent response of lumbar intervertebral disc
, Article Journal of Medical Imaging and Health Informatics ; Volume 1, Issue 3 , 2011 , Pages 246-251 ; 21567018 (ISSN) ; Haghpanahi, M ; Wang, J. L ; Parnianpour, M ; Sharif University of Technology
2011
Abstract
Investigation of the relationship between different types of mechanical loading and the failure of the intervertebral disc requires a well-defined finite element model. The objective of this paper was to develop and validate a nonlinear axisymmetric poroelastic finite element model of intervertebral disc and show its capability for studying the time-dependent response. After presenting the poroelastic model of intervertebral disc, the results of prolonged (short-term and long-term creep tests) and cyclic loading were compared with in vivo and in vitro experimental data. The trends predicted by FE model agreed well with measured experimental data and showed its validity for dynamic analysis....
An axisymmetric poroelastic model for description of the short-term and long-term creep behavior of L4-L5 intervertebral disc
, Article 2011 1st Middle East Conference on Biomedical Engineering, MECBME 2011, Sharjah, 21 February 2011 through 24 February 2011 ; 2011 , Pages 308-311 ; 9781424470006 (ISBN) ; Haghpanahi, M ; Parnianpour, M ; Wang, J. L ; Sharif University of Technology
2011
Abstract
Understanding the relationship between different kinds of mechanical loading and the failure of the intervertebral disc is difficult to study in vivo and in vitro. Through finite element studies some of these issues may be overcome enabling more detailed assessment of the biomechanical behavior of the intervertebral disc. The objective of this paper is to develop a nonlinear axisymmetric poroelastic finite element model of intervertebral disc and show its capability for studying the time-dependent response of disc. After comparison of the response of different models in quasi-static analysis, the poroelastic model of intervertebral disc is presented and the results of a short-term and...
A regenerative approach towards recovering the mechanical properties of degenerated intervertebral discs: Genipin and platelet-rich plasma therapies
, Article Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine ; Volume 231, Issue 2 , 2017 , Pages 127-137 ; 09544119 (ISSN) ; Wang, J. L ; Abdollahi, M ; Hsu, Y. C ; Parnianpour, M ; Khalaf, K ; Sharif University of Technology
SAGE Publications Ltd
2017
Abstract
Degenerative disc disease, associated with discrete structural changes in the peripheral annulus and vertebral endplate, is one of the most common pathological triggers of acute and chronic low back pain, significantly depreciating an individual's quality of life and instigating huge socioeconomic costs. Novel emerging therapeutic techniques are hence of great interest to both research and clinical communities alike. Exogenous crosslinking, such as Genipin, and platelet-rich plasma therapies have been recently demonstrated encouraging results for the repair and regeneration of degenerated discs, but there remains a knowledge gap regarding the quantitative degree of effectiveness and...
Biomechanical response of intact, degenerated and repaired intervertebral discs under impact loading – Ex-vivo and In-Silico investigation
, Article Journal of Biomechanics ; Volume 70 , March , 2018 , Pages 26-32 ; 00219290 (ISSN) ; Wang, J. L ; Parnianpour, M ; El-Rich, M ; Khalaf, K ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
Understanding the effect of impact loading on the mechanical response of the intervertebral disc (IVD) is valuable for investigating injury mechanisms and devising effective therapeutic modalities. This study used 24 porcine thoracic motion segments to characterize the mechanical response of intact (N = 8), degenerated (Trypsin-denatured, N = 8), and repaired (Genepin-treated, N = 8) IVDs subject to impact loading. A meta-model analysis of poroelastic finite element simulations was used in combination with ex-vivo creep and impact tests to extract the material properties. Forward analyses using updated specimen-specific FE models were performed to evaluate the effect of impact duration. The...
Prediction of the thorax/pelvis orientations and L5–S1 disc loads during various static activities using neuro-fuzzy
, Article Journal of Mechanical Science and Technology ; Volume 34, Issue 8 , 7 August , 2020 , Pages 3481-3485 ; ISSN: 1738494X ; Sayyaadi, H ; Arjmand, N ; Sharif University of Technology
Korean Society of Mechanical Engineers
2020
Abstract
Spinal posture including thorax/pelvis orientations as well as loads on the intervertebral discs are crucial parameters in biomechanical models and ergonomics to evaluate the risk of low back injury. In vivo measurement of spinal posture toward estimation of spine loads requires the common motion capture techniques and laboratory instruments that are costly and time-consuming. Hence, a closed loop algorithm including an artificial neural network (ANN) and fuzzy logic is proposed here to predict the L5–S1 segment loads and thorax/pelvis orientations in various 3D reaching activities. Two parts namely a fuzzy logic strategy and an ANN from this algorithm; the former, developed based on the...
Disc size markedly influences concentration profiles of intravenously administered solutes in the intervertebral disc: A computational study on glucosamine as a model solute
, Article European Spine Journal ; Vol. 23, issue. 4 , April , 2014 , p. 715-723 ; Shirazi-Adl, A ; Parnianpour, M ; Urban, J. P. G ; Sharif University of Technology
Abstract
Purpose: Tests on animals of different species with large differences in intervertebral disc size are commonly used to investigate the therapeutic efficacy of intravenously injected solutes in the disc. We hypothesize that disc size markedly affects outcome. Methods: Here, using a small non-metabolized molecule, glucosamine (GL) as a model solute, we calculate the influence of disc size on transport of GL into rat, rabbit, dog and human discs for 10 h post intravenous-injection. We used transient finite element models and considered an identical GL supply for all animals. Results: Huge effects of disc size on GL concentration profiles were found. Post-injection GL concentration in the rat...
Computational pharmacokinetics of solute penetration into human intervertebral discs-Effects of endplate permeability, solute molecular weight and disc size
, Article Journal of Biomechanics ; Volume 45, Issue 13 , 2012 , Pages 2195-2202 ; 00219290 (ISSN) ; Shirazi Adl, A ; Urban, J. P. G ; Parnianpour, M ; Sharif University of Technology
Abstract
A finite element model is developed to predict the penetration time-history of three different solutes into the human lumbar disc following intravenous injection. Antibiotics are routinely administered intravenously in spinal surgery to prevent disc infection. Successful prophylaxis requires antibiotics to reach adequate inhibitory levels. Here, the transient diffusion of cephazolin is investigated over 10. h post-injection in a human disc model subject to reported concentrations in the blood stream as the prescribed boundary sources. Post-injection variation of cephazolin concentrations in the disc adjacent to supply sources closely followed the decay curve in the blood stream and fell...
Computational investigation of sulphate diffusion into the dog disc
, Article 2011 18th Iranian Conference of Biomedical Engineering, ICBME 2011, 14 December 2011 through 16 December 2011 ; December , 2011 , Pages 161-164 ; 9781467310055 (ISBN) ; Shirazi Adl, A ; Urban, J ; Parnianpour, M ; Hoviattalab, M ; Sharif University of Technology
2011
Abstract
We proposed a model to investigate the transient diffusion of drug (sulphate) into the intervertebral disc. Using finite element method, drug diffusion was simulated and the concentration of diffused drug in each region of disc including Nucleus pulpous (NP), Inner annulus fibroses (IA), and Outer annulus fibroses (OA) was measured. In addition, to investigate the role of CEP permeability on the amount of diffused drug, model was simulated with different cartilage endplate (CEP) permeability. Having obtained concentration distribution for different cases, it was clearly shown that the amount of diffused drug is affected by the endplate permeability and the more permeable CEP, the more...
Investigation of low back pain using system modeling
, Article Advanced Science Letters ; Volume 19, Issue 5 , 2013 , Pages 1260-1264 ; 19366612 (ISSN) ; Malik, A. S ; Xia, L ; Wang, J. L ; Nikkhoo, M ; Parnianpour, M ; Khan, M. I ; Sharif University of Technology
2013
Abstract
This paper focuses on characterization of intervertebral disc behavior upon fatigue stress. It consists in in-vitro experiments to measure intervertebral disc deformation with regard to forces applied to produce fatigues test. In this paper, a system modeling based non-invasive method to assess back pain is proposed which may be used for designing of prediction model to predict the failure of intervertebral disc (IVD) experiencing fatigue loading. An artificial compression fracture was simulated in the lower level of vertebra followed by a poly(methyl methacrylate) (PMMA) bone cement injection. Fatigue loading was applied on the specimens and the load was incrementally increased form 650 N...
Fatigue loaded intervertebral disc analysis for low back pain using nonlinear black-box model
, Article IFMBE Proceedings ; Volume 39 , 2013 , Pages 513-517 ; 16800737 (ISSN) ; 9783642293047 (ISBN) ; Malik, A. S ; Xia, L ; Nikkhoo, M ; Wang, J. L ; Parnianpour, M ; Humayun, J ; Sharif University of Technology
2013
Abstract
This paper presents recent developments on effects of rest and fatigue loading on properties of healthy vertebra discs. A comparison of different approaches used in literature to study the properties of intervertebral disc is presented. The major achievements in this area so far are discussed in the context of their advantages and disadvantages. The past approaches are based on bio-mechanical models which mostly used statistical techniques for the analysis and estimation of fatigue loaded Intervertebral Disc (IVD). However, those modeling techniques were not flexible enough for analysis of customized tests. In this paper, we applied System Identification (SI) based NLARX modeling technique...