A Triaxial-Measurement Shear-Test Device for Soft Biological Tissues

Dokos, Socrates; LeGrice, Ian J.; Smaill, Bruce H.; Kar, Julia; Young, Alistair A.

doi:10.1115/1.1289624

Cited by 89 publications

(54 citation statements)

References 13 publications

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“…Viscoelastic material characterization can be best accomplished by varying loading histories over different modes of deformation since volume changes (bulk) and shape changes (shear) relate to different mechanisms of deformation 3 . Common modes of deformation used on soft tissues include: uniaxial compression/extension 17,[22][23][24][25] , shear 26,27 , indentation 6,8,10,12,[14][15][16] , torsion 5,28 , grasping 9 , and aspiration 29 . To characterize the time-dependent large strain response of soft tissues a few types of loading histories are most commonly used: creep response to a constant step load 14 , stress relaxation under a constant step displacement 9,15,19,25 , and constant strain rate ramp loading and unloading cycles 9,15,16,25 .…”

mentioning

confidence: 99%

Identifying a Minimal Rheological Configuration: A Tool for Effective and Efficient Constitutive Modeling of Soft Tissues

Jordan

Kerdok

Howe

et al. 2011

Journal of Biomechanical Engineering

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We describe a modeling methodology intended as a preliminary step in the identification of appropriate constitutive frameworks for the time-dependent response of biological tissues. The modeling approach comprises a customizable rheological network of viscous and elastic elements governed by user-defined 1D constitutive relationships. The model parameters are identified by iterative nonlinear optimization, minimizing the error between experimental and model-predicted structural (load-displacement) tissue response under a specific mode of deformation. We demonstrate the use of this methodology by determining the minimal rheological arrangement, constitutive relationships, and model parameters for the structural response of various soft tissues, including ex-vivo perfused porcine liver in indentation, ex-vivo porcine brain cortical tissue in indentation, and ex-vivo human cervical tissue in unconfined compression. Our results indicate that the identified rheological configurations provide good agreement with experimental data, including multiple constant strain-rate load/unload tests and stress-relaxation tests. Our experience suggests that the described modeling framework is an efficient tool for exploring a wide array of constitutive relationships and rheological arrangements, which can subsequently serve as a basis for 3D constitutive model development and finite-element implementations. The proposed approach can also be employed as a self-contained tool to obtain simplified 1D phenomenological models of the structural response of biological tissue to single-axis manipulations for applications in haptic technologies.

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mentioning

confidence: 99%

Identifying a Minimal Rheological Configuration: A Tool for Effective and Efficient Constitutive Modeling of Soft Tissues

Jordan

Kerdok

Howe

et al. 2011

Journal of Biomechanical Engineering

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“…Similar results were observed at ω = 1.6, 2.0, and 2.5 rad/s (data are not shown here). The intra-cycle strain stiffening was also observed from gels of other biological molecules or tissues, including gluten gels [86] , fibrin gels [87] , actin filament network [41] , pedal mucus of snails [48] , bovine brain tissues [88] and myocardium isolated from rat heart septum [89] . Storm et al [90] reported the strain stiffening of various biological gels including actin, collagen, fibrin and vimentin.…”

Section: Linear Viscoelasticitymentioning

confidence: 94%

Large amplitude oscillatory shear studies on the strain-stiffening behavior of gelatin gels

et al. 2014

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Linear and nonlinear viscoelasticity of gelatin solutions was investigated by rheology. The dynamic mechanical properties during the sol-gel transition of gelatin followed the time-cure superposition. The fractal dimension d f of the critical gel was estimated as 1.76, which indicated a loose network. A high sol fraction w s = 0.61 was evaluated from the plateau modulus by semi-empirical models. Strain-stiffening behavior was observed under large amplitude oscillatory shear (LAOS) for the gelatin gel. The strain and frequency dependence of the minimum strain modulus G M , energy dissipation E d , and nonlinear viscoelastic parameter N E was illustrated in Pipkin diagrams and explained by the strain induced helix formation reported previously by others. The BST model described the strain-stiffening behavior of gelatin gel quite well, whereas the Gent and worm-like chain network models overestimated the strain-stiffening at large strains.

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“…Equation (7) is the two-constant version of the energy function for the Mooney-Rivlin material (7) where C 1 and C 2 are material constants, and C 1 , C 2 > 0. The simplest polynomial based energy function is the neo-Hookean model (the case where C 2 = 0 in the Mooney-Rivlin model) and it is given by: (8) Ogden form of strain energy: Departing from the practice of writing the strain energy as a function of strain invariants I 1 and I 2 , Ogden 28 proposed a more general form of strain invariant for isotropic material, (9) where α is a real number, positive or negative. The Ogden form strain energy function can be written as: (10) where the C k 's are constants and k is the number of terms included in the summation.…”

Section: Hyperelastic Strain Energy Functions For Isotropic Incompresmentioning

confidence: 99%

Constitutive modeling of liver tissue: Experiment and theory

Gao

Lister

Desai

2008

2008 2nd IEEE RAS &Amp; EMBS International Conference on Biomedical Robotics and Biomechatronics

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Realistic surgical simulation requires incorporation of the mechanical properties of soft tissue in mathematical models. In actual deformation of soft-tissue during surgical intervention, the tissue is subject to tension, compression, and shear. Therefore, characterization and modeling of soft-tissue in all these three deformation modes are necessary. In this paper we applied two types of pure shear test, unconfined compression and uniaxial tension test to characterize porcine liver tissue. Digital image correlation technique was used to accurately measure the tissue deformation field. Due to gravity and its effect on the soft tissue, a maximum stretching band was observed from the relative strain field on sample undergoing tension and pure shear test. The zero strain state was identified according to the position of this maximum stretching band. Two new constitutive models based on combined exponential/logarithmic and Ogden strain energy were proposed. The models are capable to represent the observed non-linear stress-strain relation of liver tissue for full range of tension and compression and also the general response of pure shear.

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A Triaxial-Measurement Shear-Test Device for Soft Biological Tissues

Cited by 89 publications

References 13 publications

Identifying a Minimal Rheological Configuration: A Tool for Effective and Efficient Constitutive Modeling of Soft Tissues

Identifying a Minimal Rheological Configuration: A Tool for Effective and Efficient Constitutive Modeling of Soft Tissues

Large amplitude oscillatory shear studies on the strain-stiffening behavior of gelatin gels

Constitutive modeling of liver tissue: Experiment and theory

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