Mechanical Characterization of Anisotropic Planar Biological Soft Tissues Using Large Indentation: A Computational Feasibility Study

Over the last few years, research interest in tissue engineering as an alternative for current treatment and replacement strategies for cardiovascular and heart valve diseases has significantly increased. In vitro mechanical conditioning is an essential tool for engineering strong implantable tissues [1]. Detailed knowledge of the mechanical properties of the native tissue as well as the properties of the developing engineered constructs is vital for a better understanding and control of the mechanical conditioning process. The nonlinear and anisotropic behavior of soft tissues puts high demands on their mechanical characterization. Current standards in mechanical testing of soft tissues include (multiaxial) tensile testing and indentation tests. Uniaxial tensile tests do not provide sufficient information for characterizing the full anisotropic material behavior, while biaxial tensile tests are difficult to perform, and boundary effects limit the test region to a small central portion of the tissue. In addition, characterization of the local tissue properties from a tensile test is non-trivial. Indentation tests may be used to overcome some of these limitations. Indentation tests are easy to perform and when indenter size is small relative to the tissue dimensions, local characterization is possible. We have demonstrated that by recording deformation gradients and indentation force during a spherical indentation test the anisotropic mechanical behavior of engineered cardiovascular constructs can be characterized [2]. In the current study this combined numerical-experimental approach is used on Tissue Engineered Heart Valves (TEHV).

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STUDY ON MECHANICAL CHARACTERIZATION OF LIVER TISSUE BASED ON HAPTIC DEVICES FOR VIRTUAL SURGICAL SIMULATION

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519416400169 ◽

2016 ◽

Vol 16 (08) ◽

pp. 1640016 ◽

Cited By ~ 4

Author(s):

JING YANG ◽

LINGTAO YU ◽

LAN WANG ◽

HONGYANG LI ◽

QI AN

Keyword(s):

Soft Tissue ◽

Constitutive Equation ◽

Soft Tissues ◽

Mechanical Characterization ◽

Surgical Simulation ◽

Surgical Instruments ◽

Compression Tests ◽

Haptic Devices ◽

Liver Tissues

In recent years, virtual surgical simulation has been one of the hot direction of digital medical research, it is mainly used in teaching, training, diagnosis, preoperative planning, rehabilitation and modeling and analysis of surgical instruments. The modeling of soft tissue of human organs is the basis to realize the virtual surgical simulation. The quasi-linear viscoelastic (QLV) theory has been proposed by Fung, and it was widely used for modeling the constitutive equation of soft tissues. The purpose of this study is to determine the mechanical characterization of the liver soft tissue based on the PHANTOM Omni Haptic devices. Five parameters are included in the constitutive equation with QLV theory, which must be determined experimentally. The specimens were obtained from fresh porcine liver tissues in vitro. The liver tissues were cut into 14[Formula: see text]mm[Formula: see text][Formula: see text][Formula: see text]14[Formula: see text]mm[Formula: see text][Formula: see text][Formula: see text]14[Formula: see text]mm cubes. Two types of unconfined compression tests were performed on cube liver specimens. Puncture tests were performed on the complete liver. The material parameters of the QLV constitutive equation were obtained by fitting the experimental data. These parameters will provide the references for the computational modeling of the liver in the virtual surgical simulation.

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Suction based mechanical characterization of superficial facial soft tissues

Journal of Biomechanics ◽

10.1016/j.jbiomech.2015.10.039 ◽

2015 ◽

Vol 48 (16) ◽

pp. 4279-4286 ◽

Cited By ~ 26

Author(s):

J. Weickenmeier ◽

M. Jabareen ◽

E. Mazza

Keyword(s):

Soft Tissues ◽

Mechanical Characterization ◽

Facial Soft Tissues

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Mechanical characterization of a bifunctional Tetronic hydrogel adhesive for soft tissues

Journal of Biomedical Materials Research Part A ◽

10.1002/jbm.a.35310 ◽

2014 ◽

Vol 103 (3) ◽

pp. 861-868 ◽

Cited By ~ 8

Author(s):

Lindsey Sanders ◽

Roland Stone ◽

Kenneth Webb ◽

Thompson Mefford ◽

Jiro Nagatomi

Keyword(s):

Soft Tissues ◽

Mechanical Characterization

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Mechanical characterization of anisotropic planar biological soft tissues using finite indentation: Experimental feasibility

Journal of Biomechanics ◽

10.1016/j.jbiomech.2007.08.006 ◽

2008 ◽

Vol 41 (2) ◽

pp. 422-429 ◽

Cited By ~ 45

Author(s):

Martijn A.J. Cox ◽

Niels J.B. Driessen ◽

Ralf A. Boerboom ◽

Carlijn V.C. Bouten ◽

Frank P.T. Baaijens

Keyword(s):

Soft Tissues ◽

Mechanical Characterization

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Mechanical characterization of functionally graded soft materials with ultrasound elastography

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2018.0075 ◽

2019 ◽

Vol 377 (2144) ◽

pp. 20180075 ◽

Cited By ~ 2

Author(s):

Guo-Yang Li ◽

Zhao-Yi Zhang ◽

Jialin Qian ◽

Yang Zheng ◽

Wenli Liu ◽

...

Keyword(s):

Mechanical Properties ◽

Dispersion Relation ◽

Soft Tissues ◽

Mechanical Characterization ◽

Applied Mathematics ◽

Soft Materials ◽

Functionally Graded ◽

Ultrasound Elastography ◽

Transient Wave

Functionally graded soft materials (FGSMs) with microstructures and mechanical properties exhibiting gradients across a spatial volume to satisfy specific functions have received interests in recent years. How to characterize the mechanical properties of these FGSMs in vivo/in situ and/or in a non-destructive manner is a great challenge. This paper investigates the use of ultrasound elastography in the mechanical characterization of FGSMs. An efficient finite-element model was built to calculate the dispersion relation for surface waves in FGSMs. For FGSMs with large elastic gradients, the measured dispersion relation can be used to identify mechanical parameters. In the case where the elastic gradient is smaller than a certain critical value calculated here, our analysis on transient wave motion in FGSMs shows that the group velocities measured at different depths can infer the local mechanical properties. Experiments have been performed on polyvinyl alcohol (PVA) cryogel to demonstrate the usefulness of the method. Our analysis and the results may not only find broad applications in mechanical characterization of FGSMs but also facilitate the use of shear wave elastography in clinics because many diseases change the local elastic properties of soft tissues and lead to different material gradients. This article is part of the theme issue ‘Rivlin's legacy in continuum mechanics and applied mathematics’.

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