Department of Electrical and Electronic Engineering, NEWCAT Research Institute, College of Engineering, Fukushima, Japan.
Department of Neurological Surgery, School of Medicine, Nihon University, Tokyo, Japan.
Adv Exp Med Biol. 2018;1072:301-305. doi: 10.1007/978-3-319-91287-5_48.
Multi-channel NIRS, so-called optical topography (OT), allows functional mapping of the cortex; however, it takes a long time to set optodes on the head and is relatively expensive. Thus, OT is not suitable as a screening test of brain disorders evaluating many subjects. Recently, a wearable two-channel continuous wave NIRS (CW-NIRS) device has been developed. Such a simple NIRS device may be applicable as a screening test of brain disorders; however, its reliability in measurements of brain function is not yet clear. Here, we tested a two-channel CW-NIRS, which employs single LED (800 nm) for measurement of total hemoglobin (t-Hb) changes. We measured t-Hb changes in the bilateral prefrontal cortex (PFC) during mental arithmetic tasks, employing the CW-NIRS and time-resolve NIRS (TNIRS). The left-right asymmetry of the PFC activity was evaluated by calculating the laterality index (LI; (R-L)/(R + L) of t-Hb), which reflects mental stress. The interval between CW-NIRS and TNIRS measurements was 1-13 days. A significant positive correlation was observed between LI measured by CW-NIRS and TNIRS. These results suggest the reliability of the simple CW-NIRS, and it may be applicable to prevent stress-induced various diseases. Finally, it should be emphasized that the left-right asymmetry of PFC activity is relatively stable.
多通道近红外光谱（NIRS），也称为光学拓扑（OT），可以对皮质进行功能映射；但是，在头部放置光极需要很长时间并且相对昂贵。因此，OT 不适合作为评估许多受试者脑障碍的筛选测试。最近，开发了一种可穿戴的双通道连续波近红外光谱（CW-NIRS）设备。这种简单的 NIRS 设备可能适用于脑障碍的筛选测试；但是，其在脑功能测量中的可靠性尚不清楚。在这里，我们测试了一种双通道 CW-NIRS，该设备使用单个 LED（800nm）测量总血红蛋白（t-Hb）的变化。我们使用 CW-NIRS 和时间分辨近红外光谱（TNIRS）测量双侧前额叶皮层（PFC）在计算任务期间的 t-Hb 变化。通过计算 t-Hb 的左右不对称性指数（LI；（R-L）/（R + L））来评估 PFC 活动的左右不对称性，该指数反映了精神压力。CW-NIRS 和 TNIRS 测量之间的间隔为 1-13 天。CW-NIRS 测量的 LI 与 TNIRS 之间存在显著正相关。这些结果表明了简单 CW-NIRS 的可靠性，并且它可能适用于预防应激引起的各种疾病。最后，应该强调的是，PFC 活动的左右不对称性相对稳定。
