基于扩散光学断层技术进行人脑血氧活动实时成像研究

A new probe for the neuroscience to explore the brain is the technology of functional neuroimaging, which can provide dynamic process of brain areas involving into certain cognition, behavior or in a brain disease. The hemodynamics is a critical index to reflect neuronal activity. Functional magnetic resonance imaging and functional near infrared spectroscopy (NIRS) are widely used to detect the hemodynamics signals non-invasively. But they are limited by inherent shortages due to system complexity and low spatial resolution, respectively. In order to increase the spatial resolution and capture the hemodynamics in real time, the project is supposed to improve the diffusion optical tomography (DOT) to detect the hemodynamics of human brain in real time. In the project, it is the first step to configure a high-density DOT imaging system and arrange optodes covering the region of the interest optimally to detect the hemodynamics in different depth. This technique will overcome the unite depth in existing NIRS systems and obtain the oxygenation of different depth. The second step is to propose a real-time reconstruction algorithm, which is to reconstruct the brain hemodynamics from the changes of near infrared. The algorithm will take the place of existing off-line reconstruction and present a real-time hemodynamics. The seamless integration of DOT imaging system and real-time reconstruction algorithm will present a way of visualizing the hemodynamics in a portable system. It not only can lend itself to study brain functional activity under certain task, but also provides a new brain-computer interface to be employed as a inline feedback technique for the neurology rehabilitation.

脑功能活动检测技术为神经科学的开展提供了新的研究手段，可以提供脑区参与认知、行为或在疾病下的动态变化过程。脑部血氧信号是反映脑功能活动的重要指标。功能磁共振和近红外光谱技术能够采集到脑区血氧信号，但是它们分别由于系统庞大和空间分辨率低使得在应用中存在先天不足。为了既能保持较高的空间分辨率，又能实时获得脑血氧活动信息，本项目提出基于扩散光学断层成像技术的人脑血氧活动实时成像研究。首先将配置高密度扩散光学断层成像系统，提出覆盖感兴趣脑区的通道优化排布方案，突破一般功能近红外光谱成像的深度单一局限性，实现脑区血氧信号的多深度采集。然后将提出脑血氧实时重建算法，从多通道近红外光衰减信号中实时重建出脑血氧活动信息。通过该成像系统与实时重建的无缝结合，可以在便携平台上完成高分辨率脑血氧活动实时重建。这不仅能够用于研究特定任务下的脑功能活动，而且能够用于脑机接口技术，为神经功能康复等提供在线反馈技术。

脑功能活动检测技术为神经科学的开展提供了新的研究手段，可以提供脑区参与认知、行为或在疾病下的动态变化过程。脑部血氧信号是反映脑功能活动的重要指标。功能磁共振和近红外光谱技术能够采集到脑区血氧信号，但是它们分别由于系统庞大和空间分辨率低使得在中存在先天不足。为了既能保持较高的空间分辨率，又能实时获得脑血氧活动信息，本项目提出了基于扩散光学断层成像技术的人脑血氧活动实时成像研究。首先将配置高密度扩散光学断层成像系统，提出了覆盖感兴趣脑区的通道优化排布方案，突破一般功能近红外光谱成像技术的深度单一局限性，实现了脑区血氧信号的多深度采集。然后提出了脑血氧实时重建算法，从多通道近红外光衰减信号中实时重建出脑血氧活动信息。通过该成像系统与实时重建的无缝结合，形成了高分辨率脑血氧活动实时重建。这不仅能够用于研究特定任务下的脑功能活动，而且能够用于脑机接口技术，为神经功能康复等提供在线检测技术。