Hitachi, Ltd., Advanced Research Laboratory, Hatoyama, Saitama, Japan.
J Biomed Opt. 2010 Jul-Aug;15(4):046002. doi: 10.1117/1.3462996.
Optical topography (OT) based on near-infrared spectroscopy is a noninvasive technique for mapping the relative concentration changes in oxygenated and deoxygenated hemoglobin (oxy- and deoxy-Hb, respectively) in the human cerebral cortex. In our previous study, we developed a small and light wearable optical topography (WOT) system that covers the entire forehead for monitoring prefrontal activation. In the present study, we examine whether the WOT system is applicable to OT measurement while walking, which has been difficult with conventional OT systems. We conduct OT measurements while subjects perform an attention-demanding (AD) task of balancing a ping-pong ball on a small card while walking. The measured time course and power spectra of the relative concentration changes in oxy- and deoxy-Hb show that the step-related changes in the oxy- and deoxy-Hb signals are negligible compared to the task-related changes. Statistical assessment of the task-related changes in the oxy-Hb signals show that the dorsolateral prefrontal cortex and rostral prefrontal area are significantly activated during the AD task. These results suggest that our functional imaging technique with the WOT system is applicable to OT measurement while walking, and will be a powerful tool for evaluating brain activation in a natural environment.
基于近红外光谱的光学拓扑（OT）是一种无创技术，用于绘制含氧血红蛋白（氧合血红蛋白，oxy-Hb）和去氧血红蛋白（去氧血红蛋白，deoxy-Hb）在人类大脑皮层中的相对浓度变化。在我们之前的研究中，我们开发了一种小型轻便的穿戴式光学拓扑（WOT）系统，覆盖整个前额，用于监测前额叶激活。在本研究中，我们研究了 WOT 系统是否适用于传统 OT 系统难以实现的行走时的 OT 测量。我们让受试者在行走时进行一项需要注意力的（AD）任务，即保持一个乒乓球在一张小卡片上，同时进行 OT 测量。测量到的氧合血红蛋白和去氧血红蛋白相对浓度变化的时程和功率谱表明，与任务相关的变化相比，氧合血红蛋白和去氧血红蛋白信号的步相关变化可以忽略不计。对氧合血红蛋白信号的任务相关变化的统计评估表明，在 AD 任务期间，背外侧前额叶皮层和额前区被显著激活。这些结果表明，我们使用 WOT 系统的功能成像技术适用于行走时的 OT 测量，并且将成为评估自然环境中大脑激活的有力工具。
