Table 2.
Changes in Model Predictions with Increasing Complexity in the Head Model
| Tissue properties1 | Metric2 | ||
|---|---|---|---|
| load (kΩ) |
MAD Φ3 (%) |
MAD Vth3 (%) |
|
| homogeneous, isotropic | 0.82 | N/A | N/A |
| heterogeneous, isotropic3 | 0.98 | 24 | 22 |
| heterogeneous, anisotropic (Tuch CPR)4 | 0.68 | 37 | 190 |
| heterogeneous, anisotropic (classical) 4 | 0.87 | 19 | 97 |
| heterogeneous, anisotropic (volume conservation) 4 | 0.96 | 4.8 | 56 |
| heterogeneous, anisotropic (load preservation) 4 | 1.01 | 1.9 | 48 |
| heterogeneous, anisotropic (load preservation), dielectric dispersion5 |
1.07 | 0.6 | 0.30 |
1
The different approaches (italicized) for defining anisotropy are summarized in section 2.3.
2
The electrical load of contact 0 (Model 3387) in the subthalamic nucleus at t = 70 µs, the median absolute difference (MAD) in the electric potentials, and the MAD in the stimulation thresholds of corticospinal track axons.
3
MAD is between the heterogeneous, isotropic case and the homogeneous, isotropic case.
4
MAD is between the heterogeneous, anisotropic cases and the heterogeneous, isotropic case.
5
MAD is between the heterogeneous, anisotropic case with load preservation and the same case with dielectric dispersion