Estimation of the viscous properties of skin and subcutaneous tissue in uniaxial stress relaxation tests.
Knowledge of viscoelastic properties of soft tissues is essential for the finite element modelling of the stress/strain distributions in finger-pad during vibratory loading, which is important in exploring the mechanism of hand-arm vibration syndrome. In conventional procedures, skin and subcutaneous tissue have to be separated for testing the viscoelastic properties. In this study, a novel method has been proposed to simultaneously determine the viscoelastic properties of skin and subcutaneous tissue in uniaxial stress relaxation tests. A mathematical approach has been derived to obtain the creep and relaxation characteristics of skin and subcutaneous tissue using uniaxial stress relaxation data of skin/subcutaneous composite specimens. The micro-structures of collagen fiber networks in the soft tissue, which underline the tissue mechanical characteristics, will be intact in the proposed method. Therefore, the viscoelastic properties of soft tissues obtained using the proposed method would be more physiologically relevant than those obtained using the conventional method. The proposed approach has been utilized to measure the viscoelastic properties of soft tissues of pig. The relaxation curves of pig skin and subcutaneous tissue obtained in the current study agree well with those in literature. Using the proposed approach, reliable material properties of soft tissues can be obtained in a cost- and time-efficient manner, which simultaneously improves the physiological relevance.
Wu
John Z
JZ
National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA. jwu@cdc.gov
Cutlip
Robert G
RG
Welcome
Daniel
D
Dong
Ren G
RG
D000818:Animals; D003198:Computer Simulation; D003238:Connective Tissue / Q000502:physiology*; D004548:Elasticity; D066298:In Vitro Techniques; D008422:Materials Testing / Q000379:methods*; D008954:Models, Biological; D012879:Skin Physiological Phenomena; D013314:Stress, Mechanical; D013552:Swine; D014783:Viscosity