Brain Stimulation Technology Research

Controllable Pulse Shape TMS (cTMS)

We are developing a new class of efficient transcranial magnetic stimulation (TMS) devices that allow adjustment of the magnetic stimulus parameters over a wide range, which had not been possible with existing technology. Pulse shaping is accomplished through the use of high power insulated-gate bipolar transistors (IGBTs), high energy storage capacitors, and requisite snubber and control circuits, enabling switching of currents up to 7 kA with pulse widths from microseconds to hundreds of microseconds. These controllable pulse TMS (cTMS) devices could enable research and clinical applications not previously possible due to technological limitations. For instance, the cTMS machine can 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 both making the treatment more tolerable, and providing more effective blinding for randomized clinical trials. Further, cTMS can generate high frequency trains of unipolar pulses which may have more potent therapeutic effect, but have not been feasible with existing devices. Finally, cTMS generates near-rectangular pulse shapes that use less electrical energy and cause as much as four times less heating of the stimulating coil compared to conventional devices. These developments can substantially benefit TMS applications where power consumption and coil heating pose major constraints, such as in magnetic seizure therapy (MST) which is being investigated as an alternative to electroconvulsive therapy (ECT) with less cognitive side effects. This work is supported by an NIH R21 award to Dr. Peterchev and a New York State Office of Science, Technology and Academic Research (NYSTAR) award to Dr. Lisanby.

Principal Investigator

Angel Peterchev

Related Publications

• Peterchev, A. V., Spellman, T. J., and Lisanby, S. H. (2006). cTMS: A novel TMS device inducing near rectangular pulses with controllable pulse width. Neuropsychopharmacology 31(S1): S130.
• Peterchev, A. V., Kirov, G., Ebmeier, K., Scott, A., Husain, M., and Lisanby, S. H. (2007). Frontiers in TMS Technology Development: Controllable Pulse Shape TMS (cTMS) and Magnetic Seizure Therapy (MST) at 100 Hz. Biol Psychiatry 61 (8): 107S.
• Peterchev, A. V., Jalinous, R., and Lisanby, S. H. (2008).  A transcranial magnetic stimulator inducing near rectangular pulses with controllable pulse width (cTMS). IEEE Trans Biomed Eng 55 (no. 1): 257-266.
• Ugawa, Y., Huang, Y.-Z., Sommer, M., Thickbroom, G., Hamada, M., Pascual-Leone, A., Paulus, W., Classen, J., Peterchev, A., Zangen, A. (2008).  "Consensus: New Methodologies for Brain Stimulation." Brain Stimulation (accepted).
• Peterchev, A.V., Luber, B., Westin, G.G., Wager, T.D., and Lisanby, S.H. (2008). First human study of controllable pulse shape transcranial magnetic stimulation (cTMS): Effect of pulse width on corticospinal response and scalp sensation. Am Coll Neuropsychopharmacol Ann Mtg Abstr (accepted).