Development of a Novel TMS Device with Controllable Pulse Shape (cTMS)

描述（由申请人提供）：该提案响应PA-06-278（神经技术研究、开发和增强），该提案要求“显著增强现有技术……在基础或临床研究中研究大脑或行为。”我们提出了一种新的装置设计，通过引入连续的用户控制脉冲形状，大大扩展了经颅磁刺激（TMS）作为一种具有治疗潜力的无创脑功能探针的功能。经颅磁刺激通过短暂的磁脉冲诱导大脑电流来调节大脑活动。经颅磁刺激已显示出显著的抗抑郁作用，但与最佳临床结果相关的剂量参数尚未确定和优化。虽然已知神经反应对刺激脉冲的形状高度敏感，但现有的TMS设备只能对刺激波形进行有限的控制。传统的经颅磁刺激装置会诱发正弦波-指数脑电流脉冲，而研究表明矩形脉冲会更有效。此外，临床应用中使用的高频TMS设备会诱导双向电流，而研究表明单极电流会更有效。最后，已知脉冲宽度会影响刺激效率，但在传统的TMS设备中无法控制该参数。我们的目标是设计、模拟、实现、台架测试和表征一种具有可控脉冲形状（cTMS）的新型TMS装置，能够诱导具有可控脉冲宽度和形状的近似矩形、主要为单极的大脑电流。cTMS装置使用最新的高功率半导体器件，在正、负电容器组之间切换刺激线圈。我们给出了支持cTMS系统可行性的仿真，以及矩形脉冲效率的提高。这是首个脉冲形状为矩形、宽度和方向性可控的经颅磁刺激装置，将有助于优化经颅磁刺激作为脑功能探测和更接近人类大脑生理的潜在治疗干预手段。经颅磁刺激有望用于研究和治疗精神和神经系统疾病，如抑郁症和精神分裂症，但其有效性在一定程度上受到设备限制。所提出的电子设备扩展了该技术的功能，有助于实现其实质性的临床治疗潜力。

DESCRIPTION (provided by applicant): This proposal responds to PA-06-278 (Neurotechnology Research, Development, and Enhancement) which calls for "significant enhancement of existing technologies ... to study the brain or behavior in basic or clinical research." We present a novel device design that substantially expands the functionality of transcranial magnetic stimulation (TMS) as a noninvasive probe of brain function with therapeutic potential by introducing continuous user-control of pulse shape. TMS modulates brain activity through the induction of cerebral currents by brief magnetic pulses. TMS has demonstrated significant antidepressant effects, but the dosing parameters associated with the best clinical outcome have yet to be identified and optimized. Although neural response is known to be highly sensitive to the shape of the stimulating pulse, existing TMS devices allow only limited control over stimulus waveform. Conventional TMS devices induce sinusoidal-exponential cerebral current pulses, while studies suggest that rectangular pulses will be more efficient. Further, high-frequency TMS devices used in clinical applications induce bidirectional current flow, while research suggests that unipolar currents would be more effective. Finally, pulse width is known to influence the efficiency of stimulation, but this parameter cannot be controlled in conventional TMS devices. We aim to design, simulate, implement, bench test and characterize a novel TMS device with controllable pulse shape (cTMS), capable of inducing approximately rectangular, predominately unipolar cerebral currents with controllable pulse width and shape. The cTMS device switches the stimulating coil between a positive and a negative capacitor bank, using newly available high-power semiconductor devices. We present simulations supporting the feasibility of the cTMS system, and the increased efficiency of rectangular pulses. The first TMS device with rectangular pulse shape with controllable width and directionality will facilitate optimization of TMS as a probe of brain function and as a potential therapeutic intervention more closely matched to the physiology of the human brain. TMS holds promise for studying and treating psychiatric and neurological illnesses such as depression and schizophrenia, but its effectiveness has been constrained in part by device limitations. The proposed electronic device expands the functionality of this technique, helping to bring its substantial clinical therapeutic potential to fruition.