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Characterization of Closed Head Impact Injury in Rat.

Hua Y, Akula P, Kelso M, Gu L - Biomed Res Int (2015)

Bottom Line: Results revealed that impact depth and impactor shape were the two leading factors affecting intracranial responses.An indentation depth instead of impact depth would be appropriate to characterize the influence of a large deformed rubber impactor.This work could be used to better design or compare CHI experiments.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588-0656, USA.

ABSTRACT
The closed head impact (CHI) rat models are commonly used for studying the traumatic brain injury. The impact parameters vary considerably among different laboratories, making the comparison of research findings difficult. In this work, numerical CHI experiments were conducted to investigate the sensitivities of intracranial responses to various impact parameters (e.g., impact depth, velocity, and position; impactor diameter, material, and shape). A three-dimensional finite element rat head model with anatomical details was subjected to impact loadings. Results revealed that impact depth and impactor shape were the two leading factors affecting intracranial responses. The influence of impactor diameter was region-specific and an increase in impactor diameter could substantially increase tissue strains in the region which located directly beneath the impactor. The lateral impact could induce higher strains in the brain than the central impact. An indentation depth instead of impact depth would be appropriate to characterize the influence of a large deformed rubber impactor. The experimentally observed velocity-dependent injury severity could be attributed to the "overshoot" phenomenon. This work could be used to better design or compare CHI experiments.

No MeSH data available.


Related in: MedlinePlus

Verification of rat head model with [13]. (a) Coronal view of rat head subjected to controlled cortical impact and (b) peak MPS comparisons at four different locations of the brain.
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fig3: Verification of rat head model with [13]. (a) Coronal view of rat head subjected to controlled cortical impact and (b) peak MPS comparisons at four different locations of the brain.

Mentions: The published CCI injury data [13] were used to verify the FE model. To simulate the cortical impact, a 7 mm diameter craniotomy was created on the left skull. The impactor shape and impact direction were accurately defined according to the settings in the cited publication. The relative position between the impactor and brain is shown in Figure 3(a). The impact depth and velocity were assumed to be 1.5 mm and 4 m/s, respectively. The peak maximum principal strain (MPS) was extracted at four different locations of the brain (Figure 3(a), locations 1–4), corresponding to the superior cortex, deep cortex, hippocampus, and thalamus as measured in [13].


Characterization of Closed Head Impact Injury in Rat.

Hua Y, Akula P, Kelso M, Gu L - Biomed Res Int (2015)

Verification of rat head model with [13]. (a) Coronal view of rat head subjected to controlled cortical impact and (b) peak MPS comparisons at four different locations of the brain.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4588353&req=5

fig3: Verification of rat head model with [13]. (a) Coronal view of rat head subjected to controlled cortical impact and (b) peak MPS comparisons at four different locations of the brain.
Mentions: The published CCI injury data [13] were used to verify the FE model. To simulate the cortical impact, a 7 mm diameter craniotomy was created on the left skull. The impactor shape and impact direction were accurately defined according to the settings in the cited publication. The relative position between the impactor and brain is shown in Figure 3(a). The impact depth and velocity were assumed to be 1.5 mm and 4 m/s, respectively. The peak maximum principal strain (MPS) was extracted at four different locations of the brain (Figure 3(a), locations 1–4), corresponding to the superior cortex, deep cortex, hippocampus, and thalamus as measured in [13].

Bottom Line: Results revealed that impact depth and impactor shape were the two leading factors affecting intracranial responses.An indentation depth instead of impact depth would be appropriate to characterize the influence of a large deformed rubber impactor.This work could be used to better design or compare CHI experiments.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588-0656, USA.

ABSTRACT
The closed head impact (CHI) rat models are commonly used for studying the traumatic brain injury. The impact parameters vary considerably among different laboratories, making the comparison of research findings difficult. In this work, numerical CHI experiments were conducted to investigate the sensitivities of intracranial responses to various impact parameters (e.g., impact depth, velocity, and position; impactor diameter, material, and shape). A three-dimensional finite element rat head model with anatomical details was subjected to impact loadings. Results revealed that impact depth and impactor shape were the two leading factors affecting intracranial responses. The influence of impactor diameter was region-specific and an increase in impactor diameter could substantially increase tissue strains in the region which located directly beneath the impactor. The lateral impact could induce higher strains in the brain than the central impact. An indentation depth instead of impact depth would be appropriate to characterize the influence of a large deformed rubber impactor. The experimentally observed velocity-dependent injury severity could be attributed to the "overshoot" phenomenon. This work could be used to better design or compare CHI experiments.

No MeSH data available.


Related in: MedlinePlus