title: Simple and accurate methods for quantifying deformation, disruption, and development in biological tissues.
abstract: When mechanical factors underlie growth, development, disease or healing, they often function through local regions of tissue where deformation is highly concentrated. Current optical techniques to estimate deformation can lack precision and accuracy in such regions due to challenges in distinguishing a region of concentrated deformation from an error in displacement tracking. Here, we present a simple and general technique for improving the accuracy and precision of strain estimation and an associated technique for distinguishing a concentrated deformation from a tracking error. The strain estimation technique improves accuracy relative to other state-of-the-art algorithms by directly estimating strain fields without first estimating displacements, resulting in a very simple method and low computational cost. The technique for identifying local elevation of strain enables for the first time the successful identification of the onset and consequences of local strain concentrating features such as cracks and tears in a highly strained tissue. We apply these new techniques to demonstrate a novel hypothesis in prenatal wound healing. More generally, the analytical methods we have developed provide a simple tool for quantifying the appearance and magnitude of localized deformation from a series of digital images across a broad range of disciplines.
authors.affiliation: Department of Orthopaedic Surgery, Washington University, St Louis, MO 63130, USA Department of Biomedical Engineering, Washington University, St Louis, MO 63130, USA.
authors.forename: John J
authors.initials: JJ
authors.lastname: Boyle
authors.affiliation: Department of Biomedical Engineering, Washington University, St Louis, MO 63130, USA.
authors.forename: Maiko
authors.initials: M
authors.lastname: Kume
authors.affiliation: Department of Biomedical Engineering, Washington University, St Louis, MO 63130, USA.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Wyczalkowski
authors.affiliation: Department of Biomedical Engineering, Washington University, St Louis, MO 63130, USA.
authors.forename: Larry A
authors.initials: LA
authors.lastname: Taber
authors.affiliation: Department of Computer Science and Engineering, Washington University, St Louis, MO 63130, USA.
authors.forename: Robert B
authors.initials: RB
authors.lastname: Pless
authors.affiliation: The Wallace H. Coulter Department of Biomedical Engineering, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA.
authors.forename: Younan
authors.initials: Y
authors.lastname: Xia
authors.affiliation: Department of Mechanical Engineering and Materials Science, Washington University, St Louis, MO 63130, USA genin@wustl.edu.
authors.forename: Guy M
authors.initials: GM
authors.lastname: Genin
authors.affiliation: Department of Orthopaedic Surgery, Washington University, St Louis, MO 63130, USA Department of Mechanical Engineering and Materials Science, Washington University, St Louis, MO 63130, USA Department of Biomedical Engineering, Washington University, St Louis, MO 63130, USA thomopouloss@wudosis.wustl.edu.
authors.forename: Stavros
authors.initials: S
authors.lastname: Thomopoulos
mesh_terms: D000465:Algorithms; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008954:Models, Biological
keywords: material failure; strain localization; texture correlation