A finite element model (FEM) of cerebral contusion in the rat was developed and compared to experimental injury maps demonstrating blood-brain barrier (BBB) breakdown. The model was exercised at the nine unique loading conditions used experimentally. Logistic regressions of the following four variables demonstrated highly significant confidence in the prediction of the 50th percentile values (chi-squared, p less than 0.00001): maximum principal logarithmic strain (LEP), maximum principal stress (SP), strain energy density (SEN), and von Mises stress (MIS). However, only values for LEP were invariant across loading conditions. These results suggest that the BBB is most sensitive to LEP, and that breakdown occurs above a strain of 0.188 plus/minus 0.0324. (A)
Samenvatting