scholarly journals Indentation for Estimating the Human Tongue Soft Tissues Constitutive Law: Application to a 3D Biomechanical Model

2004 ◽  
pp. 77-83 ◽  
Author(s):  
Jean-Michel Gérard ◽  
Jacques Ohayon ◽  
Vincent Luboz ◽  
Pascal Perrier ◽  
Yohan Payan
Keyword(s):  
Soft Tissues ◽  
Biomechanical Model ◽  
Constitutive Law ◽  
Human Tongue

THORAX INJURY CRITERIA ASSESSMENT THROUGH NON-LETHAL IMPACT USING AN ENHANCED BIOMECHANICAL MODEL

2017 ◽  
Vol 17 (07) ◽  
pp. 1740027 ◽  
Author(s):  
MICHÈLE BODO ◽  
ANTHONY BRACQ ◽  
REMI DELILLE ◽  
CHRISTOPHE MARECHAL ◽  
SÉBASTIEN ROTH
Keyword(s):  
Lung Injury ◽  
Injury Risk ◽  
Soft Tissues ◽  
Biomechanical Model ◽  
Local Stress ◽  
The Body ◽  
Constitutive Law ◽  
Maximum Pressure ◽  
Fe Model ◽  
Injury Criteria

Ballistic injury refers to the interaction of a projectile and the human body, resulting in penetration or blunt trauma. In order to consider both consequences, a hydrodynamic elastoplastic constitutive law was implemented in a numerical FE model of the human torso to simulate soft tissues behavior and to evaluate their injury risk. This law, derived from 20% ballistic gelatin, was proven to be very efficient and biofidelic for penetrating ballistic simulation in soft tissues at very high velocity. In this study, the ability of the hydrodynamic law to simulate blunt ballistic trauma is evaluated by the replication of Bir et al.’s (2004) experiments, which is a reference test of the literature for nonpenetrating ballistic impact. Lung injury criteria were also investigated through the Bir et al.’s experiments numerical replication. Human responses were evaluated in terms of mechanical parameters, which can be global (acceleration of the body, viscous criteria and impact force) or local (stress, pressure and displacement). Output results were found to be in experimental corridors developed by Bir et al., and the maximum pressure combined with the duration of the peak of pressure in the lungs seems to be a good predictor for lung injury.

Relaxation and Creep Quasilinear Viscoelastic Models for Normal Articular Cartilage

1984 ◽  
Vol 106 (2) ◽  
pp. 159-164 ◽  
Author(s):  
B. R. Simon ◽  
R. S. Coats ◽  
S. L.-Y. Woo
Keyword(s):  
Articular Cartilage ◽  
Soft Tissues ◽  
Least Squares Method ◽  
Viscoelastic Model ◽  
Generalized Least Squares ◽  
Constitutive Law ◽  
Analytical Models ◽  
Creep Data ◽  
Bovine Articular Cartilage ◽  
Generalized Least Squares Method

A quasilinear viscoelastic model was used to develop relaxation and creep forms for a constitutive law for soft tissues. Combined relaxation and cyclic test data as well as preconditioned and nonpreconditioned creep data were used to demonstrate the approach for normal bovine articular cartilage. Values for mechanical parameters in the analytical models were determined using a generalized least squares method.

scholarly journals Foot Modeling and Smart Plantar Pressure Reconstruction from Three Sensors

2014 ◽  
Vol 8 (1) ◽  
pp. 84-92 ◽  
Author(s):  
Hussein Abou Ghaida ◽  
Serge Mottet ◽  
Jean-Marc Goujon
Keyword(s):  
Pressure Distribution ◽  
Plantar Pressure ◽  
Soft Tissues ◽  
Pressure Sensors ◽  
Biomechanical Model ◽  
Standing Position ◽  
Average Error ◽  
Pressure Measurements ◽  
Human Foot ◽  
Plantar Pressure Distribution

In order to monitor pressure under feet, this study presents a biomechanical model of the human foot. The main elements of the foot that induce the plantar pressure distribution are described. Then the link between the forces applied at the ankle and the distribution of the plantar pressure is established. Assumptions are made by defining the concepts of a 3D internal foot shape, which can be extracted from the plantar pressure measurements, and a uniform elastic medium, which describes the soft tissues behaviour. In a second part, we show that just 3 discrete pressure sensors per foot are enough to generate real time plantar pressure cartographies in the standing position or during walking. Finally, the generated cartographies are compared with pressure cartographies issued from the F-SCAN system. The results show 0.01 daN (2% of full scale) average error, in the standing position.

scholarly journals Invariant Theory for Dispersed Transverse Isotropy: An Efficient Means for Modeling Fiber Splay

2004 ◽  
Author(s):  
D. R. Einstein ◽  
A. D. Freed ◽  
I. Vesley
Keyword(s):  
Invariant Theory ◽  
Soft Tissues ◽  
Structural Model ◽  
Transverse Isotropy ◽  
Three Dimensional ◽  
Constitutive Law ◽  
Fiber Direction ◽  
Fiber Stress ◽  
Element Analysis ◽  
Model Modification

Microstructual studies suggest that in some tissues, collagen fibers are approximately normally distributed about a mean preferred fiber direction. Structural constitutive equations that account for this dispersion of fibers have been shown to capture the mechanical complexity of these tissues quite well. However, such descriptions are computationally cumbersome for two-dimensional fiber distributions, let alone for fully three dimensional fiber populations. We have developed a new constitutive law for such tissues, based on a novel invariant theory for dispersed transverse isotropy. The model is polyconvex and fits biaxial data for aortic valve tissue as accurately as the standard structural model. Modification of the fiber stress-strain law requires no re-formulation of the constitutive tangent matrix, making the model flexible for different types of soft-tissues. Most importantly, the model is computationally expedient in a finite element analysis.

scholarly journals Genioglossus and Intrinsic Electromyographic Activities in Impeded and Unimpeded Protrusion Tasks

2009 ◽  
Vol 101 (1) ◽  
pp. 276-282 ◽  
Author(s):  
Lora J. Pittman ◽  
E. Fiona Bailey
Keyword(s):  
Motor Unit ◽  
Biomechanical Model ◽  
Force Transducer ◽  
Single Motor Unit ◽  
Genioglossus Muscle ◽  
Tongue Muscle ◽  
Single Motor ◽  
Human Tongue ◽  
Tongue Muscles ◽  
Tongue Position

Eight muscles invest the human tongue: four extrinsic muscles have external origins and insert into the tongue body and four intrinsic muscles originate and terminate within the tongue. Previously, we noted minimal activation of the genioglossus tongue muscle during impeded protrusion tasks (i.e., having subjects push the tongue against a force transducer), suggesting that other muscles play a role in the production of tongue force. Accordingly, we sought to characterize genioglossus tongue muscle activities during impeded and unimpeded protrusion tasks (i.e., having subjects slowly and smoothly move the tongue out of their mouth). Electromyographic (EMG) and single motor-unit potentials of the extrinsic genioglossus muscle were recorded with tungsten microelectrodes and EMG activities of intrinsic tongue muscles were recorded with hook-wire electrodes inserted into the anterior tongue body. Tongue position was detected by an isotonic transducer coupled to the tongue tip. Protrusive force was detected by a force transducer attached to a rigid bar. Genioglossus and intrinsic tongue muscles were simultaneously active in both impeded and unimpeded protrusion tasks. Genioglossus whole muscle EMG and single motor-unit activities changed faithfully as a function of tongue position, with increased discharge associated with protrusion and decreased discharge associated with retraction back to the rest position. In contrast, during the impeded protrusion task drive the genioglossus muscle remained constant as protrusion force increased. Conversely, intrinsic tongue muscle activities appropriately followed changes in both tongue position and force. Importantly, we observed significantly higher levels of intrinsic muscle activity in the impeded protrusion task. These observations suggest that protrusion of the human tongue requires activation of the genioglossus and intrinsic protrudor muscles, with the former more important for establishing anterior–posterior tongue location and the latter playing a greater role in the generation of protrusive force. A biomechanical model of these actions is provided and discussed.

scholarly journals Machine-Learning based model order reduction of a biomechanical model of the human tongue

2021 ◽  
Vol 198 ◽  
pp. 105786
Author(s):  
Maxime Calka ◽  
Pascal Perrier ◽  
Jacques Ohayon ◽  
Christelle Grivot-Boichon ◽  
Michel Rochette ◽  
...  
Keyword(s):  
Machine Learning ◽  
Model Order Reduction ◽  
Biomechanical Model ◽  
Order Reduction ◽  
Model Order ◽  
Human Tongue

A Biomechanical Model of Sagittal Tongue Bending

2002 ◽  
Vol 124 (5) ◽  
pp. 547-556 ◽  
Author(s):  
Vitaly J. Napadow ◽  
Roger D. Kamm ◽  
Richard J. Gilbert
Keyword(s):  
Thermal Expansion ◽  
Temperature Change ◽  
Biomechanical Model ◽  
Muscle Layer ◽  
Muscular Contraction ◽  
Thermal Expansion Coefficients ◽  
Human Tongue ◽  
Strip Theory ◽  
Mechanical Basis ◽  
Expansion Coefficients

The human tongue is a structurally complex and extremely flexible organ. In order to better understand the mechanical basis for lingual deformations, we modeled a primitive movement of the tongue, sagittal tongue bending. We hypothesized that sagittal bending is a synergistic deformation derived from co-contraction of the longitudinalis and transversus muscles. Our model of tongue bending was based on classical bimetal strip theory, in which curvature is produced when one muscle layer contracts more so than another. Contraction was modulated via mismatched thermal expansion coefficients and temperature change (to simulate muscular contraction). Our results demonstrated that synergistic contraction produced curvature and strain results which were in better correspondence to empirical results derived from tagging MRI than were the results of contraction of the longitudinalis muscle alone. This fundamental reliance of tongue bending on the synergistic contraction of its intrinsic fibers supports the muscular hydrostat theory of tongue function.

Anthropometric Data for a Piomechanical Model of the Hand

1986 ◽  
Vol 30 (8) ◽  
pp. 842-846 ◽  
Author(s):  
Bryan Buchholz
Keyword(s):  
Load Distribution ◽  
Soft Tissues ◽  
Hand Movement ◽  
Biomechanical Model ◽  
Segment Length ◽  
Anthropometric Data ◽  
Hand Tools ◽  
Mathematical Basis ◽  
Hand Grip ◽  
Digit Length

Anthropometric data has been collected for the development of a biomechanical model of the hand. This model will be used to determine the load distribution on the surface of the hand and the reaction moments required at each joint in response to contact with another object. This model will be applied to the design of hand tools and work stations, so that they may be used with the least possible mechanical stresses. The model is developed on a kinematic basis, using a system composed of joints and segments. These segments do not correspond to the physiological skeletal system, but provides a mathematical basis for hand movement and a frame to hold the skin and other soft tissues in place. This study collected data on segment length between joint centers, using radiographic techniques and the method of Peuleaux. This data has been correlated with actual bone lengths and total digit length. Anthropometric data on the depth of the soft tissues of the hand will also be required to facilitate the kinematics of hand grip posture and other hand-object contact. A knowledge of the material properties of soft tissue will be necessary to develop the mechanics required to determine the load distribution on the hand.

Flow-Induced Deformation of Poroelastic Tissues and Gels: A New Perspective on Equilibrium Pressure-Flow-Thickness Relations

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Thomas M. Quinn
Keyword(s):  
Soft Tissues ◽  
Theoretical Description ◽  
Constitutive Law ◽  
Hydraulic Permeability ◽  
Equilibrium Pressure ◽  
Flowing Fluid ◽  
Direct Measurements ◽  
Alternative Measurement ◽  
New Perspective ◽  
Strain Dependent

Hydrostatic pressure-driven flows through soft tissues and gels cause deformations of the solid network to occur, due to drag from the flowing fluid. This phenomenon occurs in many contexts including physiological flows and infusions through soft tissues, in mechanically stimulated engineered tissues, and in direct permeation measurements of hydraulic permeability. Existing theoretical descriptions are satisfactory in particular cases, but none provide a description which is easy to generalize for the design and interpretation of permeation experiments involving a range of different boundary conditions and gel properties. Here a theoretical description of flow-induced permeation is developed using a relatively simple approximate constitutive law for strain-dependent permeability and an assumed constant elastic modulus, using dimensionless parameters which emerge naturally. Analytical solutions are obtained for relationships between fundamental variables, such as flow rate and pressure drop, which were not previously available. Guidelines are provided for assuring that direct measurements of hydraulic permeability are performed accurately, and suggestions emerge for alternative measurement protocols. Insights obtained may be applied to interpretation of flow-induced deformation and related phenomena in many contexts.

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