TMS Devices

Controllable Pulse Parameter TMS

We have developed a new class of efficient transcranial magnetic stimulation (TMS) devices that allow adjustment of the magnetic stimulus parameters over a wide range. This degree of flexibility was not possible with existing technology. Pulse shaping is accomplished by employing high-power insulated-gate bipolar transistors (IGBTs) and high-energy storage capacitors, as well as snubber and control circuits, to enable switching of current up to 7 kA, with pulse widths ranging from microseconds to hundreds of microseconds. These devices could enable research trials and clinical applications not previously possible due to technical limitations. For instance, cTMS could be used to non-invasively characterize changes in neuronal membrane properties associated with brain pathology or pharmacological interventions. In addition, cTMS can produce briefer magnetic pulses than conventional TMS, which could reduce unpleasant scalp sensation. This has the advantage of making the treatment more tolerable and providing more effective blinding for randomized clinical trials.

cTMS generates nearly rectangular pulses that use less electrical energy and cause at most four times less coil heating than conventional devices.

This work is supported by the NIH, Columbia University Office of Technology Ventures, New York State Office of Science, Technology and Academic Research (NYSTAR), Coulter Foundation, and Rogue Research. The patents on cTMS technology were licensed by Rogue Research who are now producing prototype devices.