Rheological Response of Human Brain Tissue in Shear

Head injury is often attributed to transient shear stresses arising from rotation of the brain in the cranial cavity. This paper deals with the experimental determination and analytical characterization of in vitro human brain dynamic constitutive properties in pure shear. A closed loop, feedback torsional system with a self mass cancelling torque transducer is used for the experimental study. Values of the storage and loss components of the dynamic shear modulus are computed and a four parameter, linear, visco-elastic model representing brain tissue properties up to 350 Hz is presented. In addition, failure criterion in terms of limiting strains and strain rates are identified.