The human cervix is an important mechanical barrier in pregnancy which must withstand the compressive and tensile forces generated from the growing fetus. Premature cervical shortening resulting from premature cervical remodeling and alterations of cervical material properties are known to increase a woman[U+05F3]s risk of preterm birth (PTB). To understand the mechanical role of the cervix during pregnancy and to potentially develop indentation techniques for in vivo diagnostics to identify women who are at risk for premature cervical remodeling and thus preterm birth, we developed a spherical indentation technique to measure the time-dependent material properties of human cervical tissue taken from patients undergoing hysterectomy. In this study we present an inverse finite element analysis (IFEA) that optimizes material parameters of a viscoelastic material model to fit the stress-relaxation response of excised tissue slices to spherical indentation. Here we detail our IFEA methodology, report compressive viscoelastic material parameters for cervical tissue slices from nonpregnant (NP) and pregnant (PG) hysterectomy patients, and report slice-by-slice data for whole cervical tissue specimens. The material parameters reported here for human cervical tissue can be used to model the compressive time-dependent behavior of the tissue within a small strain regime of 25%.
|Original language||English (US)|
|Number of pages||9|
|Journal||Journal of the Mechanical Behavior of Biomedical Materials|
|State||Published - Jun 2014|
Bibliographical noteFunding Information:
Research reported in this publication was supported by the National Science Foundation ( BRIGE1125670 ). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Science Foundation . The authors would like to thank Noelia Zork, M.D., Maternal Fetal Medicine Fellow at the Columbia Medical Center (CUMC), for her help with specimen collection and analysis and Tamaryn Shean, Ph.D. at the UK National Physics Laboratory for assistance in setting up the indentation experiments.