title: Anisotropic material behaviours of soft tissues in human trachea: an experimental study.
abstract: BACKGROUND
  Human trachea is a multi-component structure composed of cartilage, trachealis muscle, mucosa and submucosa membrane and adventitial membrane. Its mechanical properties are essential for an accurate prediction of tracheal deformation, which has a significant clinic relevance. Efforts have been made in quantifying the material behaviour of tracheal cartilage and trachealis muscle. However, the material behaviours of other components have been least investigated.
  
  
  METHODS
  Three human cadaveric trachea specimens were used in this study. Trachealis muscle, mucosa and submucosa membrane and adventitia membrane were excised to perform the uniaxial test in axial and circumferential directions. In total, 72 tissue strips were prepared and tested. Tangent modulus was used to quantified the stiffness of each tissue strip at various stretch levels.
  
  
  RESULTS
  The obtained results indicated that all types of tracheal soft tissues were highly non-linear and anisotropic. Trachealis muscle in the circumferential direction had the most excellent extensibility; and the adventitial collagen membrane in the circumferential direction was the stiffest.
  
  
  CONCLUSIONS
  This study is helpful in understanding the material behaviour of trachea. Obtained results can be used for computational and analytic modelling to quantify the tracheal deformation.
authors.affiliation: University Department of Radiology, University of Cambridge, Cambridge, UK. zt215@cam.ac.uk
authors.forename: Zhongzhao
authors.initials: Z
authors.lastname: Teng
authors.forename: Olfa
authors.initials: O
authors.lastname: Trabelsi
authors.forename: Ignacio
authors.initials: I
authors.lastname: Ochoa
authors.forename: Jing
authors.initials: J
authors.lastname: He
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Gillard
authors.forename: Manuel
authors.initials: M
authors.lastname: Doblare
mesh_terms: D000328:Adult; D000368:Aged; D016880:Anisotropy; D003238:Connective Tissue / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009130:Muscle, Smooth / Q000502:physiology*; D020545:Respiratory Mucosa / Q000502:physiology*; D013314:Stress, Mechanical; D013718:Tensile Strength; D014132:Trachea / Q000502:physiology*; D055815:Young Adult