title: Personalized heterogeneous deformable model for fast volumetric registration.
abstract: BACKGROUND
  Biomechanical deformable volumetric registration can help improve safety of surgical interventions by ensuring the operations are extremely precise. However, this technique has been limited by the accuracy and the computational efficiency of patient-specific modeling.
  
  
  METHODS
  This study presents a tissue-tissue coupling strategy based on penalty method to model the heterogeneous behavior of deformable body, and estimate the personalized tissue-tissue coupling parameters in a data-driven way. Moreover, considering that the computational efficiency of biomechanical model is highly dependent on the mechanical resolution, a practical coarse-to-fine scheme is proposed to increase runtime efficiency. Particularly, a detail enrichment database is established in an offline fashion to represent the mapping relationship between the deformation results of high-resolution hexahedral mesh extracted from the raw medical data and a newly constructed low-resolution hexahedral mesh. At runtime, the mechanical behavior of human organ under interactions is simulated with this low-resolution hexahedral mesh, then the microstructures are synthesized in virtue of the detail enrichment database.
  
  
  RESULTS
  The proposed method is validated by volumetric registration in an abdominal phantom compression experiments. Our personalized heterogeneous deformable model can well describe the coupling effects between different tissues of the phantom. Compared with high-resolution heterogeneous deformable model, the low-resolution deformable model with our detail enrichment database can achieve 9.4× faster, and the average target registration error is 3.42 mm, which demonstrates that the proposed method shows better volumetric registration performance than state-of-the-art.
  
  
  CONCLUSIONS
  Our framework can well balance the precision and efficiency, and has great potential to be adopted in the practical augmented reality image-guided robotic systems.
authors.affiliation: Department of Computer Science and Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.|Shenzhen Key Laboratory of Virtual Reality and Human Interaction Technology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, 503644, Shenzhen, China.
authors.forename: Weixin
authors.initials: W
authors.lastname: Si
authors.affiliation: Shenzhen Key Laboratory of Virtual Reality and Human Interaction Technology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, 503644, Shenzhen, China.
authors.forename: Xiangyun
authors.initials: X
authors.lastname: Liao
authors.affiliation: Shenzhen Key Laboratory of Virtual Reality and Human Interaction Technology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, 503644, Shenzhen, China. wangqiong0319@gmail.com.
authors.forename: Qiong
authors.identifier: http://orcid.org/0000-0001-9515-7745
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Computer Science and Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.|Shenzhen Key Laboratory of Virtual Reality and Human Interaction Technology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, 503644, Shenzhen, China.
authors.forename: Pheng Ann
authors.initials: PA
authors.lastname: Heng
mesh_terms: D000005:Abdomen / Q000601:surgery; D001696:Biomechanical Phenomena; D019245:Compressive Strength; D016208:Databases, Factual; D006801:Humans; D055595:Mechanical Phenomena; D008954:Models, Biological; D066230:Patient-Specific Modeling; D019047:Phantoms, Imaging; D025321:Surgery, Computer-Assisted
keywords: Biomechanical deformable volumetric registration; Coarse-to-fine scheme; Data-driven parameters estimation; Tissue–tissue coupling