A wearable functional-brain-imaging system with full-head coverage and enhanced spatiotemporal-resolution to study complex neural circuits in human subjects

一种可穿戴的功能性大脑成像系统，具有全头部覆盖和增强的时空分辨率，用于研究人类受试者的复杂神经回路

• 批准号: 10697355
• 负责人: Peter D. D. Schwindt
• 金额: $ 102.56万
• 依托单位: SANDIA CORP-SANDIA NATIONAL LABORATORIES
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-21 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10697355
• 关键词: Adult; Auditory area; Brain; Brain imaging; Brain region; Calibration; Cerebellum; Child; Communication; Compensation; Complex; Computer software; Cortical Column; Development; Discrimination; Electroencephalography; Electronics; Environment; Epilepsy; Evaluation; Frequencies; Functional Magnetic Resonance Imaging; Goals; Grant; Head; Helmet; Human; Image; Individual; Lasers; Location; Magnetism; Magnetoencephalography; Maps; Measurement; Measures; Methods; Modeling; Monitor; Morphologic artifacts; Movement; Neurons; Neurosciences; Noise; Optics; Performance; Persons; Physics; Positioning Attribute; Premature Infant; Pump; Resolution; Rest; Saccades; Sampling; Scalp structure; Shapes; Signal Transduction; Somatosensory Cortex; Source; Structure; Subject Headings; Support System; System; Techniques; Technology; Temperature; Time; United States National Institutes of Health; Validation; Visual Cortex; advanced system; aged; clinical application; cortex mapping; cost; cranium; cryogenics; data acquisition; density; design; experimental study; human subject; imaging approach; imaging modality; imaging system; improved; magnetic field; millimeter; millisecond; neural; neural circuit; neuroimaging; neuronal circuitry; operation; prototype; scale up; sensor; signal processing; simulation; spatiotemporal; superconducting quantum interference device; temporal measurement; tool; usability; vector

PROJECT SUMMARY/ABSTRACT To develop maps at multiple scales of neuronal circuits in the human brain and study the brain dynamics, there is a need for non-invasive functional brain imaging with high spatiotemporal resolution operating in natural environments. Among non-invasive functional brain imaging methods, magnetoencephalography (MEG) is the only technology that can map cortical activity down to millimeter spatial resolution with millisecond time resolution. Current cryogenic MEG systems employ superconducting quantum interference device (SQUID) magnetometers. The cryogenic operation requires sensor arrays that are rigid and fixed in a helmet, and the helmet size is optimized to fit the largest adult heads. The rigid helmet limits source-to-sensor distances to >3 cm which compromises the maximum achievable signal-to-noise ratio (SNR) and hence spatial resolution. Furthermore, due to their design, these SQUID-based MEG systems are costly and impractical for experiments in natural environments. Recent simulation studies have shown that on-scalp MEG can maximize SNR and achieve spatial resolution approaching 1 mm. Optically pumped magnetometers (OPMs) are a valid candidate for MEG sensors, as they operate above room temperature, and the sensor layout can be conformal to the scalp. The overall objective of this project is to develop a wearable, conformable, full-head coverage, 108- channel, OPM-based MEG system with unprecedented spatial resolution approaching 1 mm. The first Aim will develop the whole-cortex 108-channel OPM array along with the supporting systems (optical, electronic, software, etc.). The OPM MEG will be installed in a magnetically shielded room so that the array can be worn and move with the subject, enabling more naturalistic study paradigms. The second Aim will leverage the high- frequency spatial features available to the on-scalp OPMs to enhance the spatial resolution of the MEG system. Given unique subjects' head shapes, adaptive sampling of the magnetic topography (image) is essential to maximize the captured spatial frequency. Hence, information-theoretic analysis will be used to maximize the spatial resolution by optimizing the sensors locations. With the array being reconfigurable, rapid calibration techniques will be developed to determine the position of each OPM for each subject. To eliminate external magnetic noise and compensate for movement-induced distortion, physics-based models will be employed. The final Aim cross validates the performance metrics of the new OPM MEG system with a commercial SQUID system. By measuring retinotopy in the visual cortex, spatial localization between the MEG systems will be compared. By stimulating cerebellar activity, it will be studied if the conformal OPM array can better capture activity in this difficult-to-study region of the brain. Finally, by measuring resting-state MEG, intrinsic network connectivity in the human brain will be captured. This project will provide a whole-head OPM array that improves MEG measurements for people of all head sizes (from premature infants to the largest adults) and enable new experimental paradigms with a wearable array operating in semi-natural settings.

项目概要/摘要 为了绘制人脑神经元回路的多尺度图并研究大脑动力学， 需要在自然条件下进行具有高时空分辨率的非侵入性功能性脑成像 环境。在非侵入性功能性脑成像方法中，脑磁图（MEG）是最先进的 唯一能够在毫秒时间内将皮质活动映射到毫米空间分辨率的技术 解决。当前的低温 MEG 系统采用超导量子干涉装置 (SQUID) 磁力计。低温操作需要刚性的传感器阵列并固定在头盔中，并且 头盔尺寸经过优化，适合最大的成人头部。刚性头盔将源到传感器的距离限制为 >3 cm，这会影响最大可实现的信噪比（SNR），从而影响空间分辨率。 此外，由于其设计原因，这些基于 SQUID 的 MEG 系统成本高昂且对于实验来说不切实际 在自然环境中。最近的模拟研究表明，头皮 MEG 可以最大限度地提高信噪比和 实现接近1毫米的空间分辨率。光泵磁力计 (OPM) 是一个有效的候选者 对于 MEG 传感器，因为它们在室温以上工作，并且传感器布局可以与 头皮。该项目的总体目标是开发一种可穿戴、舒适、全头覆盖、108- 通道、基于 OPM 的 MEG 系统具有前所未有的空间分辨率接近 1 毫米。第一个目标将 开发全皮质 108 通道 OPM 阵列以及支持系统（光学、电子、 软件等）。 OPM MEG将安装在磁屏蔽室中，以便阵列可以佩戴 并随着主题的变化，实现更自然主义的研究范式。第二个目标将利用高 头皮 OPM 可用的频率空间特征，以增强 MEG 的空间分辨率 系统。考虑到独特的受试者头部形状，磁性地形（图像）的自适应采样是 对于最大化捕获的空间频率至关重要。因此，信息论分析将用于 通过优化传感器位置来最大化空间分辨率。由于阵列可重新配置，因此可以快速 将开发校准技术来确定每个受试者的每个 OPM 的位置。消除 外部磁噪声和补偿运动引起的失真，基于物理的模型将 受雇。最终 Aim 交叉验证了新 OPM MEG 系统的性能指标 商业 SQUID 系统。通过测量视觉皮层的视网膜位置，MEG 之间的空间定位 系统将进行比较。通过刺激小脑活动，将研究保形 OPM 阵列是否可以 更好地捕捉大脑这个难以研究的区域的活动。最后，通过测量静息态 MEG， 人脑中内在的网络连接将被捕获。该项目将提供全头OPM 阵列可改善各种头部尺寸（从早产儿到最大的婴儿）的 MEG 测量 成人）并通过在半自然环境中运行的可穿戴阵列实现新的实验范式。