MRC Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX1 3TH, United Kingdom.
Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, United Kingdom.
J Neural Eng. 2022 Apr 12;19(2). doi: 10.1088/1741-2552/ac60c9.
Transcranial magnetic stimulation (TMS) is a clinically effective therapeutic instrument used to modulate neural activity. Despite three decades of research, two challenging issues remain, the possibility of changing the (a) stimulated spot and (b) stimulation type (real or sham) without physically moving the coil. In this study, a second-generation programmable TMS device with advanced stimulus shaping is introduced that uses a five-level cascaded H-bridge inverter and phase-shifted pulse-width modulation. The principal idea of this research is to obtain real, sham, and multi-locus stimulation using the same TMS system.We propose a two-channel modulation-based magnetic pulse generator and a novel coil arrangement, consisting of two circular coils with a physical distance of 20 mm between the coils and a control method for modifying the effective stimulus intensity, which leads to the live steerability of the target and type of stimulation.Based on the measured system performance, the stimulation profile can be steered ±20 mm along a line from the centroid of the coil locations by modifying the modulation index.The proposed system supports electronic control of the stimulation spot without physical coil movement, resulting in tunable modulation of targets, which is a crucial step towards automated TMS machines.
经颅磁刺激（TMS）是一种临床有效的治疗工具，用于调节神经活动。尽管已经进行了三十年的研究，但仍存在两个具有挑战性的问题，即无需物理移动线圈就有可能改变（a）刺激点和（b）刺激类型（真实或假刺激）。在这项研究中，引入了一种具有先进刺激成形功能的第二代可编程 TMS 设备，该设备使用五级级联 H 桥逆变器和相移脉冲宽度调制。本研究的主要思想是使用相同的 TMS 系统获得真实、假刺激和多焦点刺激。我们提出了一种基于双通道调制的磁脉冲发生器和一种新颖的线圈布置，由两个具有 20mm 物理距离的圆形线圈组成，并提出了一种用于修改有效刺激强度的控制方法，从而实现了目标和刺激类型的实时可操纵性。基于测量的系统性能，通过修改调制指数，可以将刺激轮廓从线圈位置的质心沿一条线±20mm 进行引导。所提出的系统支持刺激点的电子控制，无需物理线圈移动，从而实现目标的可调谐调制，这是实现自动化 TMS 机器的关键步骤。
