TMS training simulator · SimNIBS real head model
SimNIBS · Individual E-field · ernie
A real SimNIBS simulation: MagVenture MC-B70 coil, 80 A/µs, a 7-position star sensitivity sweep. The coil is shown on the skull in the exact pose the simulation used; watch how the cortical |E| (V/m) pattern and its peak shift as the position changes.
In this simulation set the coil handle points forwards and inwards: the placement was defined as "handle towards CP5", but SimNIBS assigns that direction to the coil's +y axis, and in the MC-B70 model +y is opposite the handle. The current in the brain is therefore AP rather than PA; the |E| magnitude is almost the same because of the figure-of-eight's symmetry.
How to read it: The grey body is the coil and the holder arm seen from that direction; the part lying over the head is drawn faded so the anatomy beneath stays visible. The bright yellow line is where the slice plane cuts the coil body, the light grey line where it cuts the holder; the copper rings are the two windings inside the body. Coil position and angle come from the matsimnibs pose SimNIBS used in this simulation, the body from SimNIBS's MagVenture MC-B70 model (the drawing is scaled to 80% for legibility; the field was computed with the full-size coil); the holder arm is schematic. The blue layer is |E| in grey matter; the colour scale saturates at the highest 99.9th-percentile value across positions. The white ring marks the peak in the baseline slice, the red + the selected position's own 3D peak (faded if it lies outside this slice). dI/dt only scales the absolute V/m linearly. While the peak moves by up to 15 mm, the intensity stays almost constant: the uncertainty is in where stimulation lands, not how strong it is. For research use; not validated for clinical decisions.
Pulse animation: The magnetic field was computed in these slices with SimNIBS's MC-B70 model (dipole coil); the time course is the real biphasic waveform of the MagPro X100 (peak current ≈ 3.6 kA at 80 A/µs). The ~0.3 ms pulse is slowed down to ~5 seconds. In reality the field builds up everywhere at once (quasi-static); the "spreading" you see is a given |B| value (the iso-lines) being pushed away from the coil as the current grows. The moving dots show the in-plane direction of the field lines and reverse when the current changes direction. The E-field is proportional not to |B| itself but to its rate of change (dI/dt): E is zero at peak current and largest when the current changes fastest.
© 2026 Prof. Dr. Burhanettin Uludağ. All rights reserved; may not be reproduced or republished on another site without permission.