See how a magnetic pulse
reaches the brain.
Adjust the coil, frequency, and target region. Watch the field penetrate the cortex and trigger neuronal activity — all in 3D, in real time.
Three steps to try it
The simulator is educational — not a treatment-planning tool. Use it to explore how TMS parameters change what reaches the brain.
Pick a target
Choose a brain region — like L-DLPFC for depression or OFC for OCD. The coil moves to the right spot above the scalp.
Adjust the pulse
Change frequency and intensity to see how the magnetic field shape, depth, and reach are affected in real time.
Watch it work
Run a session to see neurons fire, the field penetrate, and the connected network light up in 3D.
The simulator
Drag to rotate · scroll to zoom · click any region to target it. Controls live inside the panel — they update the 3D model immediately.
How TMS actually works
Three physical steps. Each happens in under a millisecond, repeated thousands of times in a session.
Current enters the coil
A capacitor discharges roughly 1,500 amps through copper windings in under a tenth of a millisecond, producing a rapidly-changing magnetic field perpendicular to the scalp.
Field passes through skull
The field reaches about 1.5 tesla at the coil face — strong enough to pass through bone and dura. It peaks 1 to 3 cm below the scalp and falls off quickly with depth.
Neurons depolarize
The induced electric field reaches roughly 100 V/m in the target cortex, bringing pyramidal neurons to firing threshold. A single pulse triggers action potentials across millions of cells.
The evidence base
TMS has accumulated one of the largest bodies of randomized clinical trial data in psychiatry. A few of the milestones that mattered:
- 2008
First FDA clearance
NeuroStar approved for treatment-resistant major depressive disorder in adults.
- 2013
Deep TMS
BrainsWay's H-coil reaches deeper structures than standard figure-of-eight designs.
- 2018
iTBS · OCD
Theta-burst protocol (3 min) shown non-inferior to 37-min sessions. OCD indication added.
- 2020
SAINT protocol
Accelerated iTBS achieves ~90% remission in a small RCT for severe TRD.
- 2024
Adolescent (15+)
First TMS device cleared for adolescent major depressive disorder.
Ready to take the next step?
Find a verified TMS clinic that accepts your insurance and has availability in your area. No sign-up required.