Geometric and Electric Characteristics
Tissue | Radius (mm) | Conductivity(S/m) |
Scalp | 92.0 | 0.450 |
Skull | 85.0 | 0.00563 |
Cortex | 80.0 | 0.450 |
Source 1 [3] | Source 2 [4] | Source 3 [2] | |
Bone | 0.010 | ||
White matter | 0.117 | 0.133 | 0.129 |
Grey matter | 0.228 | 0.400 | 0.200 |
Skin | 0.346 | 0.778 | 0.270 |
CSF | 1.611 | 1.538 | 1.668 |
[1] Roth,B.J.,Saypol.J. M., Hallet.,M. and Cohen,L.G. (1991 ) A theoretical calculation of the electric field induced in the cortex during magnetic stimulation. Electroencephalogaphv and Clinical Neurophyswlogy, 81 , 47-56.
[2] Holton, K. S. and Walker C. F. (1990) Correlation of a magnetic resonance brain image and tisue impedance. IEEE EMBS 92-93.
[3] Geddes L.A. and Baker L.E. (1967) 'The specific resistance of biological material: a compendium of data for the biomedical engineer and physiologist. Medical and Biological Engineering, 5 271 - 219.
[4] Geddes, L. A. (1989) Optimal stimulation duration for
extracranial cortical stimulation. Neurosuyey, 20, 94-99.