http://spectrum.ieee.org/biomedical/devices/electromagnetic-depression-treatment-nears-approval
Electromagnetic Depression Treatment Nears Approval
Deep transcranial magnetic stimulation adds to psychiatry’s arsenal of electronicremedies
Deep transcranial magnetic stimulation (TMS), as its name suggests, uses magnetic fields to stimulate activity in structures deep in the brain. The patient wears a helmet in which powerful, specially designed electromagnets have been carefully positioned. When a pulse of electricity flows through the magnets’ coils, the resulting magnetic field induces current to flow through a portion of the brain.
There are subtle differences between deep TMS and repetitive transcranial magnetic stimulation (rTMS), a brain stimulation tool widely used in research and also marketed as a treatment for depression. The electromagnetic elements in deep TMS are designed to produce a magnetic field that reaches its greatest strength deep within the brain. Ordinarily, magnetic fields fall away quickly inside the brain, but the orientation and structure of the coils in deep TMS lessens that effect. “The concept was to reduce the rate of reduction of the magnetic field as a function of distance,” says Abraham Zangen, coinventor of the technology. In contrast, rTMS typically uses a single coil that produces a tightly focused field just a few centimeters below the brain’s surface.
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