Elastic-anisotropic properties of the porcine superflexor tendon measured by instrumented indentation

Measurements of soft tissue anisotropy using instrumented indentation are of interest because of the potential for indentation-based clinical diagnostics. Shortage of previous research relating to instrumented indentation of soft tissue in the kPa range, such as tendon, motivated a protocol development phase in our study. Once indents in tendon were repeatedly successful and the protocol validated, elastic-anisotropy in tendon was studied on the premise that collagen fibers in tendon are highly-ordered and unidirectional. Samples of porcine superflexor tendon were mounted for indentation such that the collagen fibers were oriented one of three possible ways relative to the indentation probe: parallel to the probe (longitudinal indentation), perpendicular to the probe (lateral indentation), or 45° to the probe (intermediate indentation). Non-significant differences in the reduced elastic modulus of the three experimental groups suggest that porcine superflexor tendon anisotropy is not detected by instrumented indentation. Contextualizing these results within the concept of indentation strain provides support for the possibility that the critical strain required for the onset of anisotropy in tendon is perhaps beyond the deformation range on the instrumented indentation system. With respect to protocol development for instrumented indentation of soft tissues, new insight is provided into the importance of clearing the indentation probe between successive indents of biological debris to ensure data integrity.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Sangha, Harpreet

Contributors dc:contributor

• Wagoner Johnson, Amy J.

• nanoindentation
• depth-sensing indentation
• soft tissue
• biomechanics
• tendon anisotropy

Statement dc:rights

• Copyright 2014 Harpreet Sangha

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/49786

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/49786