IMAGE SURFACE SENSOR ARRAY FOR BIOMAGNETIC MEASUREMENTS

我们建议完成一个新的全头超级， 用于脑磁图（MEG）的传导图像传感器系统 人脑，实验校准和验证系统使用 物理幻象，并通过直接 与商业全头MEG阵列进行比较。成本效益的 全头系统将提供重要的能力， 用于临床应用和 基础研究MEG直接测量神经元的物理效应， 电流的时间分辨率不受缓慢的血管 与PET和fMRI测量血液学变化不同， 与神经元活动有关。高时间分辨率是 对于研究神经系统疾病尤其重要， 癫痫的时间信息是一个主要的诊断， 同步和振荡大脑活动的基础研究。 本文提出的全头部MEG系统在1999年得到了NIH的支持。 该项目的初始阶段。该系统是基于洛杉矶 Alamos-超导图像表面梯度测量的专利原理 其中磁源在表面上成像， 该表面感测组合场，就好像传感器是MEG一样 系统.完成了全头脑磁图系统的设计、制作和 组装完成约90%。其他主要成就包括 (A)实验验证了超导成像原理; (B)铌和铅成像表面性能的比较 证明了电极导线的上级性能;（C）新的低温 传感器支撑材料获得专利;（D）开发新的 软件和模拟背景抑制技术。支持现在 要求（1）完成全头脑磁图系统的组装 将所有的SQUID磁强计;（2）完成磁通锁定环的设计 实施我们新的控制和背景消除技术;（3） 实现一个功能强大实时数据采集系统 管理、显示和分析;（4）使用体模测量来测试 并校准灵敏度、成像和噪声性能以及屏蔽 传感器阵列的特性;（5）实验验证系统 使用复杂的体模;以及（6）获取实验数据， 在与NIH资助的实验相同的条件下， 视觉和躯体感觉系统的研究。 这里提出的工作将导致一个功能齐全的全头脑磁图 系统基于新的物理应用，传感器设计， 有望大幅降低系统成本的制造技术 和复杂性，同时提高系统性能。这样的系统将 对基础神经科学和临床应用都有重要价值。

We propose to complete construction of a novel whole-head super- conducting image sensor system for Magnetoenceph-alography (MEG) of the human brain, to experimentally calibrate and validate the system using physical phantoms, and to demonstrate system efficacy by direct comparison with a commercial whole-head MEG array. A cost-effective whole-head system will provide important capabilities for non-invasive functional human brain measurements for both clinical applications and basic research. MEG directly measures a physical effect for neuronal currents with temporal resolution not limited by the sluggish vascular response; unlike PET and fMRI that measure hematological changes associated with neuronal activity. High temporal resolution is particularly important for studying neurological disorders such as epilepsy where temporal information is a major diagnostic, and for fundamental studies of synchronization and oscillatory brain activity. The whole-head MEG system proposed here has been supported by NIH during the initial project period of this grant. The system is based on the Los Alamos-patented principle of super-conducting image surface gradiometry where magnetic sources are imaged on the surface and magnetometers near this surface sense the combined fields as if the sensors were MEG systems. The whole-head MEG system design is complete; fabrication and assembly are about 90% complete. Additional key accomplishments include (A) the super-conducting imaging principle was experimentally verified; (B) comparison of niobium and lead imaging surface performance demonstrated superior performance in the lead; (C) a new cryogenic sensor support material was patented; and (D) development of novel software and analog background rejection techniques. Support is now being requested to (1) complete assembly of the whole-head MEG system will all SQUID magnetometers; (2) complete flux-locked loop design implementing our new control and background cancellation techniques; (3) implement a powerful real-time data acquisition system with data management, display and analysis; (4) use phantom measurements to test and calibrate sensitivity, imaging and noise performance, and shielding characteristics of the sensor array; (5) experimentally verify system using a sophisticated phantom; and (6) acquire experimental data for human subjects under the same conditions as NIH-funded experimental studies of the visual and somatosensory systems. The work proposed here will result in a fully functional whole-head MEG system based on new physics applications, sensors design, and fabrication techniques that promise to dramatically reduce system cost and complexity while improving system performance. Such a system will be of great value to both basic neuroscience and clinical applications.