# A Review of Validation Methods for the Intracranial Response of FEHM to Blunt Impacts
## 2 Experimental Procedures Used in FEHM Validation
### Cadaver Experimentation
#### 2.1.1 Intracranial Pressure Response
The six impacts were simulated and the peak pressure response magnitudes compared to the injury outcome from the original experiment. A significantly higher peak pressure of 227 kPa was recorded for the case presenting injury than the non-injuring group, where it was \(136\pm 55\) kPa. This was used to indicate that a contusion threshold could be developed through future work. [PERSON] et al. [38] studied the intracranial response of three cadavers across six impacts with the intention of creating a tool to validate FEHM, particularly for use in automotive crash research. These authors also conducted an investigation into factors influencing the ICP response. Two of the cadavers (labeled as MS408 and MS428 in the original publication) had pressure transducers fitted in the arachnoid space of the frontal, parietal and occipital regions. Further transducers were inserted into the third and lateral ventricles in test MS428. Accelerometers were fitted to the skull and set into the brain tissue in four locations to compare the relative motion of the bodies. Limited preparation time was available for cadaver MS429 so instrumentation was reduced to a single intracerebral and frontal and occipital pressure transducers. The exact location of each piece of \begin{table}
\begin{tabular}{l l l l l l l l l l l l} \hline \hline  & \multicolumn{3}{c}{**Impactor Properties**} & \multicolumn{6}{c}{**Pressures (kPa)**} \\ \hline
36 & 5.36 & 8.75 & 7.78 & 2.30 & 136 & 79 & \(-27\) & \(-10\) & \(-64\) & \(-\) \\
37 & 5.59 & 9.94 & 7.90 & 2.00 & 141 & 74 & \(-45\) & \(-48\) & \(-60\) & \(-\) \\
38 & 5.32 & 9.60 & 10.80 & 2.42 & 139 & 66 & \(-27\) & \(-\) & \(-65\) & \(-\) \\
41 & 23.09 & 12.83 & 14.84 & 2.42 & 428 & 189 & 114 & \(-\) & \(-57\) & 47 \\
42 & 5.23 & 12.95 & 5.20 & 3.90 & \(-\) & 9 & \(-\) & \(-\) & \(-44\) & 73 \\
43 & 5.23 & 12.95 & 10.59 & 2.23 & 271 & 222 & 64 & \(-\) & \(-18\) & 108 \\
44 & 5.23 & 4.36 & 6.53 & 1.52 & 102 & 20 & 15 & \(-\) & \(-2\) & 115 \\
54 & 5.23 & 8.41 & 10.84 & 2.34 & 275 & 181 & 33 & \(-\) & \(-64\) & 48 \\ \hline \hline \multicolumn{10}{c}{Series 2} \\ \hline
46 & 5.23 & 4.42 & 1.50 & 0.31 & \(-\) & \(-\) & \(-\) & \(-\) & \(-\) & \(-\) \\
47 & 5.23 & 4.42 & 1.22 & 0.29 & \(-\) & \(-\) & \(-\) & \(-\) & \(-\) & \(-\) \\
48 & 5.23 & 4.21 & 4.27 & 1.28 & \(-\) & \(-\) & \(-\) & \(-\) & \(-\) & \(-\) \\
49 & 5.23 & 8.35 & 9.35 & 3.42 & \(-\) & \(-\) & \(-\) & \(-\) & \(-\) & \(-\) \\
50 & 5.23 & 8.35 & 6.28 & 1.49 & \(-\) & \(-\) & \(-\) & \(-\) & \(-\) & \(-\) \\
51 & 5.23 & 8.29 & 16.60 & 5.39 & \(-\) & \(-\) & \(-\) & \(-\) & \(-\) & \(-\) \\
52 & 5.23 & 8.69 & 13.34 & 4.29 & \(-\) & \(-\) & \(-\) & \(-\) & \(-\) & \(-\) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Summary of impact conditions and peak response values across all scenarios tested experimentally on cadavers by [PERSON] et al. [34]. instrumentation is reported by [PERSON] et al. [38], confirmed via an X-ray image of each cadaver taken after transducer installation. Impacts were generated by striking a stationary cadaver with a 23.4 kg impactor at velocities between 5 and 7 m/s. [PERSON] et al. [38] summarised the conditions of each impact by location, velocity and the profile of the impactor. Impact responses are reported and described through the peak linear accelerations of the skull in the \(x\) (posterior-anterior) and \(z\) (inferior-superior) directions and the peak rotational acceleration and velocity about the \(y\) (medial-lateral) axis. The intracerebral acceleration peaks are given in a single direction at each transducer as well as the peak ICP at each monitored location. Table 2 lists the reported impact conditions, whole head (skull) accelerations and pressures for each test. Further to this, the full time-history recordings of each transducer are included as appendices, as exemplified for MS428-2 in Figure 2.  
Despite there being sufficient information available to replicate all the scenarios in Table 2, test MS428-2 is the sole impact to have been applied to the validation of prominent FEHM.