In-vivo testing of biological bulk soft tissues by a non-axisymmetric tip indenter using displacement and force control

Download

index.pdf

Date

2015

Author

Ashrafi, Parinaz

Metadata

Show full item record

Item Usage Stats

196
views

222
downloads

Soft tissues of human body have complex structures and different mechanical behaviors than those of traditional engineering materials. There is a great urge to understand tissue behavior of human body. Experimental data is needed for improvement of soft tissue modeling and advancement in implants and prosthesis, as well as diagnosis of diseases. Mechanical behavior and responses change when tissue loses its liveliness and viability. One of the techniques for soft tissue testing is indentation, which is applied on live tissue in its physiological environment. Indentation affords several advantages over other types of tests such as uniaxial tension, biaxial tension, and simple shear and suction, thus it is of interest to develop new indentation techniques from which precise data can be extracted. In this study experimental data was acquired using a soft tissue indenter designed and manufactured in METU. For real time data collection computer codes with a graphical user interface was developed in LabVIEW programming software. The in-vivo force rate controlled cyclic loading test method which is novel is compared with the traditional displacement controlled cyclic loading tests. Displacement and force rate cyclic loading, and relaxation experiments were conducted on human arm. In addition to viscoelastic behavior of soft tissue, the anisotropic behavior and preconditioning behavior of human arm soft tissues were examined. Anisotropic behavior of tissue cannot be determined by axi-symmetric tips, therefore ellipsoid tips were designed and used for examining in-plane anisotropy of bulk soft tissues.Finally, precise experimental data, to be used in the computer simulations, were obtained.

Subject Keywords

Tissue engineering., Tissues, Anisotropy., Viscoelasticity., Biomechanics.

URI

http://etd.lib.metu.edu.tr/upload/12618564/index.pdf
https://hdl.handle.net/11511/24505

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Indentation and Observation of Anisotropic Soft Tissues Using an Indenter Device Ashrafi, Parinaz; Tönük, Ergin (2014-10-31) Soft tissues of human body have complex structures and different mechanical behaviors than those of traditional engineering materials. There is a great urge to understand tissue behavior of human body. Experimental data is needed for improvement of soft tissue modeling and advancement in implants and prosthesis, as well as diagnosis of diseases. Mechanical behavior and responses change when tissue loses its liveliness and viability. One of the techniques for soft tissue testing is indentation, which is appl...
In vivo indenter experiments on soft biological tissues for identification of material models and corresponding parameters Petekkaya, Ali Tolga; Tönük, Ergin; Department of Mechanical Engineering (2008) Soft biological tissues, being live and due to their physiological structures, display considerably complex mechanical behaviors. For a better understanding and use in various applications, first study to be carried out is the tests made particularly as in vivo. An indenter test device developed for this purpose in the METU, Department of Mechanical Engineering, Biomechanics Laboratory is operational. In this study, in order to carry out precise and dependable tests, initially, various tests and improvement...
IN VIVO INDENTER EXPERIMENTS VIA ELLIPSOID INDENTER TIPS TO DETERMINE THE PERSONAL AND LOCAL IN-PLANE ANISOTROPIC MECHANICAL BEHAVIOR OF SOFT BIOLOGICAL TISSUES Petekkaya, Ali Tolga; Tönük, Ergin (2011-03-01) Mechanical interaction of human body with surrounding is mostly via soft tissues because human body is nearly entirely covered with them. Finite element method, extensively used in various fields of engineering, could not reach to a similar success in simulating soft tissues (especially for modeling the interaction with exoskeletal prosteses and orthoses) mainly because soft tissue mechanical behavior is not known in detail in addition to relatively complex mechanical response of soft tissues.
Development and characterization of silk fibroin and citrus pectin based scaffolds for bone tissue engineering Ataol, Sibel; Tezcaner, Ayşen; Akdağ, Akın; Department of Biomedical Engineering (2014) Current strategies of tissue engineering aim to design and develop biologically, physicochemically and mechanically proper scaffolds. Natural polymers are gaining interest in applications since they have already many roles in biochemical pathways and have proper mechanical properties. The objective of this thesis is to develop natural silk fibroin (SF) and citrus pectin (PEC) based three-dimensional porous scaffolds for bone tissue engineering applications. Additionally, we aimed to synthesize nano calcium ...
Identification of soft tissue mechanical material model and corresponding parameters from in vivo experimental data by using inverse finite element method Üsü, Kerem; Tönük, Ergin; Department of Mechanical Engineering (2008) The purpose of this thesis is to search for the best material model for soft biological tissues in general. Different sections of human body exhibit different responses like stress relaxation, creep, hysteresis and preconditioning to external loading conditions. These body sections can be assumed as viscoelastic, poroelastic or pseudoelastic. After making the choice of the material model from one of these for the current study, the finite element model and the material code to be used with this model have b...

Citation Formats

P. Ashrafi, “In-vivo testing of biological bulk soft tissues by a non-axisymmetric tip indenter using displacement and force control,” M.S. - Master of Science, Middle East Technical University, 2015.