title: Three-dimensional reconstruction and modeling of middle ear biomechanics by high-resolution computed tomography and finite element analysis.
abstract: OBJECTIVE
  To present a systematic and practical approach that uses high-resolution computed tomography to derive models of the middle ear for finite element analysis.
  
  
  METHODS
  This prospective study included 31 subjects with normal hearing and no previous otologic disorders. Temporal bone images obtained from 15 right ears and 16 left ears were used for evaluation and reconstruction.
  
  
  METHODS
  High-resolution computed tomography of temporal bone was performed using simultaneous acquisition of 16 sections with a collimated slice thickness of 0.625 mm. All images were transferred to an Amira visualization system for three-dimensional reconstruction. The created three-dimensional model was translated into two commercial modeling packages, Patran and ANSYS, for finite element analysis.
  
  
  RESULTS
  The characteristic dimensions of the model were measured and compared with previously published histologic section data. This result confirms that the geometric model created by the proposed method is accurate except that the tympanic membrane is thicker than when measured by the histologic section method. No obvious difference in the geometrical dimension between right and left ossicles was found (P > .05). The three-dimensional model created by finite element method and predicted umbo and stapes displacements are close to the bounds of the experimental curves of Nishihara's, Huber's, Gan's, and Sun's data across the frequency range of 100 to 8000 Hz.
  
  
  CONCLUSIONS
  The model includes a description of the geometry of the middle ear components and dynamic equations of vibration. The proposed method is quick, practical, low-cost, and, most importantly, noninvasive as compared with histologic section methods.
authors.affiliation: Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan.
authors.forename: Chia-Fone
authors.initials: CF
authors.lastname: Lee
authors.forename: Peir-Rong
authors.initials: PR
authors.lastname: Chen
authors.forename: Wen-Jeng
authors.initials: WJ
authors.lastname: Lee
authors.forename: Jyh-Horng
authors.initials: JH
authors.lastname: Chen
authors.forename: Tien-Chen
authors.initials: TC
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D004432:Ear, Middle / Q000502:physiology*; D005260:Female; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional; D007368:Interferometry; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D011446:Prospective Studies; D012016:Reference Values; D012680:Sensitivity and Specificity; D013701:Temporal Bone / Q000502:physiology*; D014057:Tomography, X-Ray Computed / Q000379:methods*