Table 2.
Observed and computed centers of gravity displacements for ventricles and tumor. X, Y, and Z directions are as in Figure 1. The computations were done using geometrically non-linear finite element procedures. During the craniotomy, gravity acceleration acted in the XZ plane and formed a 24.5° angle with the Z axis.
| Center of Gravity Displacements (mm) | ||||||
|---|---|---|---|---|---|---|
| Material Model | Ventricles | Tumor | ||||
| ΔX | ΔY | ΔZ | ΔX | ΔY | ΔZ | |
| MRI Determined | 3.4 | 0.2 | 1.7 | 5.5 | −0.2 | 1.7 |
| Hyperviscoelastic material | 2.6 | −0.1 | 2.1 | 5.2 | −0.4 | 2.7 |
| Hyperelastic material | 2.6 | −0.1 | 2.1 | 5.2 | −0.4 | 2.7 |
| Linear elastic material | 2.6 | −0.1 | 2.1 | 5.0 | −0.5 | 2.7 |