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利用超导磁体线圈代替室温线圈进行经颅磁刺激（TMS）的新型仪器的可行性。这种超导 TMS 装置 (sTMS.) 利用由铌钛铜制成的 II 型超导线可承载的高电流密度。与传统室温铜基TMS磁体的大约1A/mm2相比，这种导线可以承载横截面积密度为1kA/mm2数量级的电流。由于TMS线圈产生的磁场B取决于导线中的电流、横截面积和导线匝数，因此可以使用相对较小的TMS线圈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，不需要像室温 TMS 那样需要特殊的散热器，从而使我们能够构建高密度 sTMS。在我们的初步测试中，我们能够构建一个具有 2.2 厘米直径线圈的 TMS 系统，该系统可以产生 18,000 特斯拉/秒 (T/s) 的磁场斜坡 (dB/dt)，这与刺激器尺寸为 8-12 厘米的传统 TMS 系统的 20-40 kT/s 相当。在第一阶段项目中构建的原理验证设备将采用可在约 1000V 电压下运行的电容器，而初步测试中的电容器为 100V。这将使我们能够使用直径为 2.0 cm、匝数约为 4 且优化电感为 1-2 5H 的 TMS 线圈构建能够提供 ~40 kT/s dB/dt 的 sTMS 设备。我们将在 sTMS 线圈正下方的盐溶液浴中测量电场 E，以验证该 sTMS 能够在 2-3 cm 的距离（与人脑新皮质的距离相当）处产生 ~100 mV/mm 的电场梯度。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约为 3 cm 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 sTMS 线圈可以组合起来产生线段形状的焦点涡流。通过改变施加到四个 sTMS 线圈的电流，可以连续调整该电流线的方向，以刺激具有特定方向的目标神经元。通过改变施加到所有通道的电流，可以沿着大脑表面连续调整涡流线的位置。如今，TMS 是唯一能够刺激大脑局部区域的技术，不仅可以研究大脑回路的基本功能，而且可以作为抑郁症和其他神经/精神疾病的有效治疗方式。基于所提出的设计的 TMS 设备可以显着提高 TMS 设备在其他领域的实用性，包括促进中风和其他疾病患者的损伤后重组。公共健康相关性：第二阶段将开发的多通道超导 TMS (sTMS) 和可能在商业化阶段（第三阶段）开发的全头 sTMS 系统将为 TMS 应用提供重大进展，以无创刺激人脑。这将提高 TMS 在治疗患有各种神经和精神疾病的患者方面的有效性，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。