Contents Part IV: Post Tutorials | Chapter 1: Calculate Ooccupant Injury Criterion | Print page 1.5. Pre-filtering ExplainedFigure 7 illustrates the concept of pre-filtering the acceleration signal before calculating HIC. The computation is performed as follows:X, Y, and Z components of acceleration are filtered.Resultant acceleration is plotted.HIC is calculated. « 1.4. Plot HIC with Pre-filtering 1.6. Plot CSI with Pre-filtering »