Modeling of Brain Mechanical Properties for Computer-Integrated Medicine

Many modern applications of technology to medicine, such as robotic surgery, non-rigid registration, virtual reality operation planning and surgeon training systems, and surgical simulators, require knowledge of mechanical properties of very soft tissues. In this paper we describe and identify a model of mechanical properties of brain tissue aimed in particular at integration with interactive brain atlases. A non-linear, viscoelastic model based on the generalization of the Ogden strain energy hyperelastic constitutive equation is proposed. The material parameters are identified using in-vivo experimental results. The model accounts well for brain tissue deformation behavior in both tension and compression (natural strain e〈 − 0.3, 0.2〉 ) for strain rates typical for surgical procedures. It can be immediately applied in large-scale finite element simulations and, therefore, offers the possibility of incorporating mechanics into surgical planning and training systems such as NeuroPlanner and BrainBench. Finally we show that the brain model identified based on in-vivo experiments can be applied in the more realistic in-vivo setting.