Development of Superconducting Transcranial Magnetic Stimulation (TMS)

超导经颅磁刺激（TMS）的发展

• 批准号: 7537079
• 负责人: DOUGLAS N PAULSON
• 金额: $ 11.99万
• 依托单位: TRISTAN TECHNOLOGIES, INC.
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-15 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7537079
• 关键词: Area; Automobile Driving; Bathing; Brain; Brain region; Caliber; Copper; Count; Depth; Development; Devices; Dimensions; Disease; Effectiveness; Electronics; Evaluation; Feasibility Studies; Fund Raising; Head; Heating; Helium; Human; Injury; Liquid substance; Marketing; Measures; Mental Depression; Mental disorders; Modality; Mood Disorders; Neocortex; Neurologic; Neurons; Niobium; Numbers; Patients; Phase; Physiological; Positioning Attribute; Public Health; Ramp; Rehabilitation therapy; Reporting; Resistance; Saline; Scalp structure; Shapes; Solutions; Staging; Stroke; Surface; System; Tail; Techniques; Temperature; Testing; Titanium; Today; Transcranial magnetic stimulation; Traumatic Brain Injury; Work; base; commercialization; cryogenics; density; design; fiberglass; instrument; magnetic field; novel; size; voltage

DESCRIPTION (provided by applicant): We propose to test the feasibility of developing a novel instrument for transcranial magnetic stimulation (TMS) utilizing superconducting magnet coils instead of room-temperature coils. This superconducting TMS device (sTMS.) takes advantage of high current density that can be carried by type II superconducting wires made of niobium-titanium-copper. Such a wire can carry currents with a density on the order of 1 kA/mm2 of cross- sectional area compared to about 1 A/mm2 for conventional room-temperature copper-based TMS magnets. Since the magnetic field B generated by a TMS coil depends on the current in the wire, cross sectional area and number of turns of wire, it is possible to use relatively small TMS coils for eventually constructing a high- density multi-channel or even whole-head sTMS. No heat will be generated by the superconducting segment of the TMS circuit. Thus there is no need for a special heat sink as it is necessary for room-temperature TMSs, allowing us to construct a high-density sTMS. In our preliminary test we were able to construct a TMS system with a 2.2 cm diameter coil that could produce a magnetic field ramp (dB/dt) of 18,000 tesla/sec (T/s), which is comparable to 20-40 kT/s for conventional TMS systems having stimulator dimensions of 8-12 cm. The proof- of-principle device to be constructed in this Phase I project will employ capacitors that can operate at ~1000 V compared to 100V in the preliminary test. This will allow us to construct an sTMS device capable of delivering dB/dt of ~40 kT/s using a 2.0 cm diameter TMS coil with ~4 turns having an optimized inductance of 1-2 5H. We will measure the electrical field E in a bath of saline solution just below the sTMS coil to verify that this sTMS is capable of generating an electrical gradient of ~100 mV/mm at a distance of 2-3 cm comparable to the distance of the neocortex of a human brain. Once we establish the feasibility of constructing a single-channel sTMS, we propose to construct a 37-channel sTMS in Phase II to demonstrate that a high-density sTMS with a channel spacing of ~3 cm can be constructed. Compared to conventional TMS devices, this multichannel system is expected to provide many significant advantages. Four diagonal sTMS coils can be combined to produce a focal eddy current shaped like a line segment. The orientation of this current line can be adjusted continuously by varying the currents applied to the four sTMS coils in order to stimulate target neurons with a specific orientation. The position of the eddy current line can be adjusted continuously along the surface of the brain by varying the currents applied to all the channels. Today, TMS is the only technique capable of stimulating focal regions of the brain to study not only basic functions of the brain circuit, but also to serve as a useful treatment modality for depression and other neurological/psychiatric disorders. TMS devices based on the proposed design could significantly increase the usefulness of TMS devices in other areas including facilitation of post-injury reorganization in patients with stroke and other disorders. PUBLIC HEALTH RELEVANCE: The multichannel superconducting TMS (sTMS) to be developed during Phase II and a whole-head sTMS systems to be developed possibly during the commercialization stage (Phase III) would provide significant advances in applications of TMS to stimulate the human brain noninvasively. This will increase the effectiveness of TMS in treating patients with various neurological and psychiatric disorders including depression and mood disorder in general, and stroke and traumatic brain injury that require rehabilitation.

描述（由申请人提供）：我们建议测试开发一种新型经颅磁刺激（TMS）仪器的可行性，该仪器使用超导磁体线圈代替室温线圈。这种超导TMS装置（sTMS.）利用了由铌-钛-铜制成的II型超导导线可以携带的高电流密度。与传统的室温铜基TMS磁体的密度约为1 kA/mm2的横截面积相比，这种导线可以携带密度约为1 kA/mm2的电流。由于TMS线圈产生的磁场B取决于导线中的电流，横截面积和导线的匝数，因此可以使用相对较小的TMS线圈来最终构建高密度多通道甚至全头sTMS。TMS电路的超导部分不会产生热量。因此，不需要特殊的散热器，因为它是室温tms所必需的，允许我们构建高密度的sTMS。在我们的初步测试中，我们能够构建一个直径为2.2厘米的TMS系统，该线圈可以产生18,000特斯拉/秒（T/秒）的磁场斜坡（dB/dt），这与具有8-12厘米刺激器尺寸的传统TMS系统的20-40 kT/s相当。与初步测试的100V电压相比，在第一期项目中构建的原理验证装置将采用可在~ 1000v电压下工作的电容器。这将使我们能够构建一个sTMS器件，能够使用直径2.0 cm的TMS线圈提供~40 kT/s的dB/dt，约4匝，优化电感为1-2 5H。我们将在sTMS线圈下方的盐水溶液中测量电场E，以验证该sTMS能够在2-3厘米的距离上产生~100 mV/mm的电梯度，与人类大脑新皮层的距离相当。一旦我们确定了构建单通道sTMS的可行性，我们建议在第二阶段构建37通道sTMS，以证明可以构建通道间距为~ 3cm的高密度sTMS。与传统的TMS设备相比，这种多通道系统有望提供许多显着的优势。四个对角的sTMS线圈可以组合在一起产生线段形状的聚焦涡流。通过改变施加在四个sTMS线圈上的电流，可以连续调整电流线的方向，从而以特定的方向刺激目标神经元。通过改变施加在所有通道上的电流，可以沿着大脑表面连续调整涡流线的位置。今天，经颅磁刺激是唯一一种能够刺激大脑的焦点区域来研究大脑回路的基本功能的技术，也是一种有效的治疗抑郁症和其他神经/精神疾病的方法。基于所提出设计的TMS装置可以显著提高TMS装置在其他领域的有用性，包括促进脑卒中和其他疾病患者损伤后重组。公共卫生相关：多通道超导经颅磁刺激（sTMS）将在第二阶段开发，全头部经颅磁刺激系统可能在商业化阶段（第三阶段）开发，这将为经颅磁刺激在无创人脑刺激方面的应用提供重大进展。这将提高经颅磁刺激治疗各种神经和精神疾病患者的有效性，包括一般的抑郁症和情绪障碍，以及需要康复的中风和创伤性脑损伤。