Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA.
J Neural Eng. 2011 Jun;8(3):036016. doi: 10.1088/1741-2560/8/3/036016. Epub 2011 May 4.
The characteristics of transcranial magnetic stimulation (TMS) pulses influence the physiological effect of TMS. However, available TMS devices allow very limited adjustment of the pulse parameters. We describe a novel TMS device that uses a circuit topology incorporating two energy storage capacitors and two insulated-gate bipolar transistor (IGBT) modules to generate near-rectangular electric field pulses with adjustable number, polarity, duration, and amplitude of the pulse phases. This controllable pulse parameter TMS (cTMS) device can induce electric field pulses with phase widths of 10-310 µs and positive/negative phase amplitude ratio of 1-56. Compared to conventional monophasic and biphasic TMS, cTMS reduces energy dissipation up to 82% and 57% and decreases coil heating up to 33% and 41%, respectively. We demonstrate repetitive TMS trains of 3000 pulses at frequencies up to 50 Hz with electric field pulse amplitude and width variability less than the measurement resolution (1.7% and 1%, respectively). Offering flexible pulse parameter adjustment and reduced power consumption and coil heating, cTMS enhances existing TMS paradigms, enables novel research applications and could lead to clinical applications with potentially enhanced potency.
经颅磁刺激（TMS）脉冲的特性影响 TMS 的生理效应。然而，现有的 TMS 设备只能对脉冲参数进行非常有限的调整。我们描述了一种新颖的 TMS 设备，该设备采用一种电路拓扑结构，其中包含两个储能电容器和两个绝缘栅双极晶体管（IGBT）模块，可产生具有可调脉冲数、极性、持续时间和脉冲相位幅度的近矩形电场脉冲。这种可控制脉冲参数 TMS（cTMS）设备可以产生相位宽度为 10-310 µs 且正/负相位幅度比为 1-56 的电场脉冲。与传统的单相和双相 TMS 相比，cTMS 分别将能量耗散降低了 82%和 57%，并将线圈加热降低了 33%和 41%。我们在高达 50 Hz 的频率下展示了 3000 个脉冲的重复 TMS 训练，电场脉冲幅度和宽度的变化小于测量分辨率（分别为 1.7%和 1%）。cTMS 提供了灵活的脉冲参数调整以及降低的功率消耗和线圈加热，增强了现有的 TMS 范式，可实现新的研究应用，并可能在潜在增强功效的情况下导致临床应用。
