Rheological Response of Human Brain Tissue in Shear

Abstract

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.

Magnetic resonance elastography of the brain

“…Further improvements in the data acquisition and processing techniques will improve the precision of brain MRE and may allow for improved distinction between normal and pathologic tissue. Shear stiffness measurements in the literature of mammalian brain tissue (Arbogast et al 1998;Bilston et al 1997;Donnelly et al 1997;Estes et al 1970;Fallenstein et al 1969;Galford et al 1970;Green et al 2006;Hamhaber et al 2007;Hirakawa et al 1981;Ljung 1975;Metz et al 1970;Shuck et al 1972;Uffmann et al 2004;Walsh et al 1976;Wang et al 1972). The studies were performed in vitro, ex vivo and in vivo (denoted by *) using a variety of experimental techniques (shear/strain, load cell, pressure transducer, vibrating probe and MR elastography).…”

Fluid percussion injury device for the precise control of injury parameters

“…The mechanical response of non-linear viscoelastic brain tissues to a low strain rate deformation will likely be different than its response to a high strain rate (Shuck and Advani, 1972;Elkin and Morrison, 2013;Pamidi and Advani, 1978). Systemic investigation of relevant loading parameters and the resulting responses are important for understanding injury-induced pathophysiological mechanisms and developing experimental models that are relevant to the human clinical situation under different types of head trauma.…”

“…Tissues of the brain have viscoelastic behavior (Shuck and Advani, 1972;Cheng et al, 2008;Elkin and Morrison, 2013;Shulyakov et al, 2011;Pamidi and Advani, 1978;Wang and Wineman, 1972). At high rates of loading (peak pressure) viscoelastic materials behave stiffer and the magnitude of injury loading will induce higher stresses in the brain with lower amounts of deformation.…”

“…The term "rate" is defined as the rise time to peak pressure. Because brain tissue is viscoelastic, both rate and magnitude of the pressure will affect how the tissue responds mechanically and thus could lead to unique pathophysiologies (Magou et al, 2011;Shuck and Advani, 1972;Arbogast et al, 1997). Greatly contrasting examples would be a head impact from a fall vs. a blast wave; the latter being several order of magnitude higher in rate.…”

“…The contribution of the rate of injury was recognized in early head injury physical models (Sundaramurthy et al, 2012;Shuck and Advani, 1972;Arbogast et al, 1997;Smith et al, 1997;Liu et al, 1975;Adams et al, 1983;King et al, 2003), where injury was correlated with rotational acceleration of the head. Currently, there are no animal models directly examining whether the pathophysiological outcome of injury depends on the rate of the delivered injury.…”