Integrated EEG/NIR Sensor System for Infants

描述（由申请人提供）：拟议项目的长期目标是设计一种具有成本效益、重量轻、集成的全头部EEG/NIR脑成像和数据分析系统，用于无创记录新生儿和幼儿的脑活动。该系统将允许床旁监测立即处于危险中的新生儿，并早期识别和干预预测发育障碍和认知缺陷的异常。位于头皮表面的128个组合光电电极的密集阵列将同时记录脑电活动（脑电图，EEG）和脑血氧变化（近红外光谱，NIRS），为大脑功能的时间和位置提供补充措施。对于第一阶段，第一个具体目标是为新生儿开发一个原型EEG/NIR传感器网络。源和传感器光电极将被组装到一个柔性聚合物网络中（建立在EGI现有的用于128通道EEG记录的测地线网络结构上）。除了容纳用于EEG采集的银-氯化银电极外，每个源光电极将包含用于将NIR通量传输到头部的微型双波长LED，并且每个检测器光电极将包含用于测量恢复的NIR通量的光检测器和前置放大器（通量变化分数与氧合和脱氧血红蛋白浓度的变化相关）。微型屏蔽线将光电电极连接到子系统，该子系统将调制电流驱动到源LED或执行EEG和NIR信号的模数转换。多个独特的调制频率将使得使用FFT解调在检测器处驱动和区分所有光源成为可能。EEG、NIR、实验刺激和其他记录的生理信号（例如，EKG、EMG）将使用EGI现有的Amp服务器技术进行同步。通过反复的内部测试，婴儿蚊帐和系统设计将进一步完善，以改善传感器接触，最大限度地减少运动伪影，解决舒适性和稳定性问题，并确保系统整体的实用性。第二个具体目标是实地测试原型系统的数据完整性，功能和可用性。将通过与在新生儿医院病房拥有研究特权和新生儿密集阵列脑电图专业知识的研究员合作，在出生后24小时内收集10名新生儿的同时静息状态脑电图和近红外数据。将正式评估光电电极网的贴合性、安全性和舒适性，包括传感器定位、接触和压力以及应用的便利性。将通过专家评审评估EEG数据的完整性，以确定与之前使用EGI标准HCGSN EEG系统采集的静息EEG数据在信号质量、噪声和运动伪影方面的可比性。将评估NIRS数据完整性，以确定信号恢复随与光学扩散计算模型一致的发射器距离的下降，以及是否存在易于识别的心脏脉冲。目标3是定义一个商业上可行的婴儿综合EEG/NIR系统的架构和在第二阶段开发它的路径。公共卫生相关性：该项目的目标是开发第一个能够提供有关新生儿和幼儿神经功能的实时空间和时间脑成像信息的轻量级设备。这样的发展将有利于立即处于危险中的新生儿的床边监测，并为我们提供了一个令人难以置信的机会，以确定在非常年幼的婴儿的结构和功能异常，可能会导致后来出现的发育障碍。这种早期识别对于制定早期干预措施至关重要，这些干预措施可能会减轻甚至阻止疾病的出现。

DESCRIPTION (provided by applicant): The long-term objective of the proposed project is to design a cost-effective, light-weight, integrated, whole- head EEG/NIR brain imaging and data analysis system for non-invasive recording of brain activity in neonates and young children. This system will permit bedside monitoring of immediate at-risk neonates, and early identification and intervention for abnormalities that predict developmental disabilities and cognitive deficits. A dense-array of 128 combined opto-electrodes sitting on the surface of the scalp will simultaneously record brain electrical activity (electroencephalography, EEG), and cerebral blood oxygenation changes (near-infrared spectroscopy, NIRS), providing complementary measures on the timing and location of brain function. For Phase I, the first Specific Aim is to develop a prototype EEG/NIR sensor net for neonates. Source and sensor opto-electrodes will be assembled into a flexible polymer web (building on EGI's existing geodesic net structure used for 128-channel EEG recording). In addition to housing silver-silver chloride electrodes for EEG acquisition, each source opto-electrode will contain miniature dual-wavelength LEDs for transmitting NIR flux into the head and each detector opto-electrode will contain light detectors and pre-amplifiers for measuring recovered NIR flux (the fractional flux changes being related to changes in oxygenated and deoxygenated hemoglobin concentrations). Miniature shielded wires will connect the opto-electrodes to subsystems that either drive modulated currents to the source LEDs or perform analog-to-digital conversion of the EEG and NIR signals. Multiple unique modulation frequencies will make it possible to drive and distinguish all light sources at detectors using FFT demodulation. EEG, NIR, experimental stimuli, and other recorded physiological signals (e.g., EKG, EMG) will be synchronized using EGI's existing Amp Server technology. Through iterative in-house testing, the infant net and system design will be further refined to improve sensor contact, minimize movement artifact, address comfort and stability, and ensure practical usability of the system as a whole. The second Specific Aim is to field-test the prototype system for data integrity, functionality and usability. Simultaneous resting state EEG and NIR data will be collected on 10 neonates within 24 hours of birth through collaboration with the Subcontractor, who has research privileges at a neonatal hospital unit and expertise in neonatal dense-array EEG. The opto-electrode net will be formally evaluated for fit, safety and comfort, including sensor positioning, contact and pressure, and ease of application. EEG data integrity will be assessed by expert review for comparability to resting EEG data previously collected with EGI's standard HCGSN EEG system in terms of signal quality, and noise and movement artifact. NIRS data integrity will be assessed for fall-off in signal recovery with distance from emitters that is consistent with the computational model of optical diffusion, and for the presence of a readily identifiable cardiac pulse. Aim 3 is to define the architecture for a commercially viable integrated EEG/NIR system for infants and the path for developing it within Phase II. PUBLIC HEALTH RELEVANCE: The goal of this project is to develop the first lightweight device capable of providing real-time spatial and temporal brain imaging information regarding newborn and young infant neural functioning. Such a development would facilitate bedside monitoring of immediate at-risk newborns and offer us the incredible opportunity to identify in very young infants the structural and functional abnormalities that may contribute to later emerging developmental disabilities. Such early identification is vital to the development of early interventions that may mitigate or even preclude the emergence of the disorder.