Significance: Functional near-infrared spectroscopy (fNIRS) is a technique for detecting regional hemodynamic responses associated with neural activation in the cerebral cortex. The absorption changes due to hemodynamic changes in the scalp cause considerable signal contamination in the fNIRS measurement. A method for extracting hemodynamic changes in the cerebral tissue is required for reliable fNIRS measurement. Aim: To exclusively detect cerebral functional hemodynamic changes, we developed an fNIRS technique using reflectance modulation of the scalp surface. Approach: The theoretical feasibility of the proposed method was proven by a simulation calculation of light propagation. Its practical feasibility was evaluated by a phantom experiment and brain activation simulation mimicking human fNIRS experiments. Results: The simulation calculation revealed that the partial path length of the scalp was changed by reflectance modulation of the scalp surface. The influence of absorption change in the superficial layer was successfully reduced by the proposed method, using only measurement data, in the phantom experiment. The proposed method was applicable to human experiments of standard designs, achieving statistical significance within an acceptable experimental time-frame. Conclusions: Removal of the scalp hemodynamic effect by the proposed technique will increase the quality of fNIRS data, particularly in measurements in neonates and infants that typically would require a dense optode arrangement.

中文翻译：

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通过头皮表面的反射调制在功能性近红外光谱中独家检测脑血流动力学。

意义：功能性近红外光谱 (fNIRS) 是一种检测与大脑皮层神经激活相关的区域血流动力学反应的技术。由于头皮血液动力学变化引起的吸收变化会导致 fNIRS 测量中相当大的信号污染。可靠的 fNIRS 测量需要一种提取脑组织血流动力学变化的方法。目的：为了专门检测脑功能性血流动力学变化，我们开发了一种使用头皮表面反射调制的 fNIRS 技术。方法：通过光传播的模拟计算证明了该方法的理论可行性。通过模拟人类 fNIRS 实验的幻影实验和大脑激活模拟来评估其实际可行性。结果：模拟计算表明，头皮表面的反射率调制改变了头皮的部分路径长度。在体模实验中，仅使用测量数据，所提出的方法成功降低了表层吸收变化的影响。所提出的方法适用于标准设计的人体实验，在可接受的实验时间范围内实现统计显着性。结论：通过所提出的技术消除头皮血流动力学效应将提高 fNIRS 数据的质量，特别是在通常需要密集光极排列的新生儿和婴儿的测量中。在体模实验中，仅使用测量数据，所提出的方法成功降低了表层吸收变化的影响。所提出的方法适用于标准设计的人体实验，在可接受的实验时间范围内实现统计显着性。结论：通过所提出的技术消除头皮血流动力学效应将提高 fNIRS 数据的质量，特别是在通常需要密集光极排列的新生儿和婴儿的测量中。在体模实验中，仅使用测量数据，所提出的方法成功降低了表层吸收变化的影响。所提出的方法适用于标准设计的人体实验，在可接受的实验时间范围内实现统计显着性。结论：通过所提出的技术消除头皮血流动力学效应将提高 fNIRS 数据的质量，特别是在通常需要密集光极排列的新生儿和婴儿的测量中。