A viscoelastic study of scalp, brain, and dura

Galford, J.E.; McElhaney, James H.

doi:10.1016/0021-9290(70)90007-2

Cited by 296 publications

(182 citation statements)

References 4 publications

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“…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).…”

Section: Discussionmentioning

confidence: 99%

Magnetic resonance elastography of the brain

et al. 2008

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The purpose of this study was to obtain normative data using magnetic resonance elastography (MRE) to: [a] obtain estimates of the shear modulus of human cerebral tissue in vivo, and [b] assess a possible age dependence of the shear modulus of cerebral tissue in healthy adult volunteers. MR elastography studies were performed on tissue-simulating gelatin phantoms and 25 healthy adult volunteers. The data were analyzed using spatio-temporal filters and a local frequency estimating algorithm. Statistical analysis was performed using a paired t-test. The mean shear stiffness of cerebral white matter was 13.6 kPa (95% CI 12.3 to 14.8 kPa); while that of gray matter was lower at 5.22 kPa (95% CI 4.76 to 5.66 kPa). The difference was statistically significant (p < 0.0001).

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Section: Discussionmentioning

confidence: 99%

Magnetic resonance elastography of the brain

et al. 2008

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“…Here we assume that the mechanical properties of the woodpecker's brain and dura matter are the same as the human being's, [11][12][13][14][15] the components except the beak and hyoid are linear-viscoelasticity. Simply the viscosity parameters of the dead brain and dura matter are referenced to the work of Sack et al 12 and the viscosity of bone is referenced to those of Lunde et al 16 and Matthew et al 17 The wood is considered as the spruce wood, 18 which is a kind of the woodpecker's favorite trees.…”

Section: B Materials Properties and The Fe Modelmentioning

confidence: 99%

Numerical study of the impact response of woodpecker's head

Zhu

Guo

et al. 2012

AIP Advances

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Woodpecker can beat trees 20-25 times per second and lasts for several seconds, with a 1200 g deceleration, but it appears that they never get brain concussion. How does the stress wave propagate from the beak tip to brain and how does a woodpecker protect itself from brain damage? In this paper, we establish a finite element model of typical woodpecker head based on its X-ray tomography images and conduct the numerical analysis of the impact response of the woodpecker's head by using a viscoelasticity material model. Especially, the woodpecker head response to an impact speed of 7 m/s is investigated to explore the stress concentration zone and how the stress wave propagates in its head. The numerical results show that the stress wave in the head propagates from the upper beak to back skull and is reduced by the specific structure of hyoid and viscoelasticity of biomaterials. The maximum stresses in skull and brain are both below the safe level. The stress in skull almost disappears before the next impact. The stress in brain lasts for a little longer but shows smaller value with little variation. The stress is impossible to accumulate in the limited pecking time, so the brain damage can be avoided

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“…The instrumentation mounting bracket was attached securely to the skull, creating a rigid connection among the instrumentation, surrogate skull material, and head. A latex rubber material (Mold Builder [1.25 mm thick]; ETI, Fields Landing, CA) with properties similar to scalp 14,33,42 was used to cover the occipital portion of the polypropylene skull; this material remained adherent throughout the tests.…”

Section: Construction Of the Anthropomorphic Dummy Of An Infantmentioning

confidence: 99%

Anthropomorphic simulations of falls, shakes, and inflicted impacts in infants

Prange

Coats²,

Duhaime³

et al. 2003

Journal of Neurosurgery

164

117

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Object. Rotational loading conditions have been shown to produce subdural hemorrhage and diffuse axonal injury. No experimental data are available with which to compare the rotational response of the head of an infant during accidental and inflicted head injuries. The authors sought to compare rotational deceleration sustained by the head among free falls, from different heights onto different surfaces, with those sustained during shaking and inflicted impact. Methods. An anthropomorphic surrogate of a 1.5-month-old human infant was constructed and used to simulate falls from 0.3 m (1 ft), 0.9 m (3 ft), and 1.5 m (5 ft), as well as vigorous shaking and inflicted head impact. During falls, the surrogate experienced occipital contact against a concrete surface, carpet pad, or foam mattress. For shakes, investigators repeatedly shook the surrogate in an anteroposterior plane; inflicted impact was defined as the terminal portion of a vigorous shake, in which the surrogate's occiput made contact with a rigid or padded surface. Rotational velocity was recorded directly and the maximum (peak—peak) change in angular velocity and the peak angular acceleration were calculated. Analysis of variance revealed significant increases in the and associated with falls onto harder surfaces and from higher heights. During inflicted impacts against rigid surfaces, the and were significantly greater than those measured under all other conditions. Conclusions. Vigorous shakes of this infant model produced rotational responses similar to those resulting from minor falls, but inflicted impacts produced responses that were significantly higher than even a 1.5-m fall onto concrete. Because larger accelerations are associated with an increasing likelihood of injury, the findings indicate that inflicted impacts against hard surfaces are more likely to be associated with inertial brain injuries than falls from a height less than 1.5 m or from shaking.

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A viscoelastic study of scalp, brain, and dura

Cited by 296 publications

References 4 publications

Magnetic resonance elastography of the brain

Magnetic resonance elastography of the brain

Numerical study of the impact response of woodpecker's head

Anthropomorphic simulations of falls, shakes, and inflicted impacts in infants

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