Bagherzadeh Hedyeh, Meng Qinglei, Lu Hanbing, Hong Elliott, Yang Yihong, Choa Fow-Sen
Department of Computer Science and Electrical Engineering, University of Maryland, Baltimore County, Baltimore, MD 21250, USA.
Neuroimaging Research Branch, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA.
BME Front. 2022 Mar 5;2022:9854846. doi: 10.34133/2022/9854846. eCollection 2022.
. There is a need to develop rodent coils capable of targeted brain stimulation for treating neuropsychiatric disorders and understanding brain mechanisms. We describe a novel rodent coil design to improve the focality for targeted stimulations in small rodent brains. . Transcranial magnetic stimulation (TMS) is becoming increasingly important for treating neuropsychiatric disorders and understanding brain mechanisms. Preclinical studies permit invasive manipulations and are essential for the mechanistic understanding of TMS effects and explorations of therapeutic outcomes in disease models. However, existing TMS tools lack focality for targeted stimulations. Notably, there has been limited fundamental research on developing coils capable of focal stimulation at deep brain regions on small animals like rodents. . In this study, ferromagnetic cores are added to a novel angle-tuned coil design to enhance the coil performance regarding penetration depth and focality. Numerical simulations and experimental electric field measurements were conducted to optimize the coil design. . The proposed coil system demonstrated a significantly smaller stimulation spot size and enhanced electric field decay rate in comparison to existing coils. Adding the ferromagnetic core reduces the energy requirements up to 60% for rodent brain stimulation. The simulated results are validated with experimental measurements and demonstration of suprathreshold rodent limb excitation through targeted motor cortex activation. . The newly developed coils are suitable tools for focal stimulations of the rodent brain due to their smaller stimulation spot size and improved electric field decay rate.
需要开发能够进行靶向脑刺激的啮齿动物线圈，用于治疗神经精神疾病和理解脑机制。我们描述了一种新型的啮齿动物线圈设计，以提高在小型啮齿动物大脑中进行靶向刺激的聚焦性。经颅磁刺激（TMS）在治疗神经精神疾病和理解脑机制方面正变得越来越重要。临床前研究允许进行侵入性操作，对于TMS效应的机制理解以及疾病模型中治疗结果的探索至关重要。然而，现有的TMS工具缺乏靶向刺激的聚焦性。值得注意的是，在开发能够对啮齿动物等小动物的深部脑区进行聚焦刺激的线圈方面，基础研究有限。在本研究中，将铁磁芯添加到一种新型的角度调谐线圈设计中，以提高线圈在穿透深度和聚焦性方面的性能。进行了数值模拟和实验电场测量以优化线圈设计。与现有线圈相比，所提出的线圈系统显示出明显更小的刺激光斑尺寸和增强的电场衰减率。添加铁磁芯可将啮齿动物脑刺激的能量需求降低多达60%。通过靶向运动皮层激活对阈上啮齿动物肢体兴奋进行实验测量和演示，验证了模拟结果。新开发的线圈因其较小的刺激光斑尺寸和改进的电场衰减率，是啮齿动物脑聚焦刺激的合适工具。
