Tracking Brain Development From Neonates to the Elderly by Hemoglobin Phase Measurement Using Functional Near-Infrared Spectroscopy
Liang, Tian, Yang, Arimitsu, Takahashi, Sassaroli, Fantini, Niu, Minagawa, Tong (2021) Tracking Brain Development From Neonates to the Elderly by Hemoglobin Phase Measurement Using Functional Near-Infrared Spectroscopy IEEE J Biomed Health Inform (IF: 7.7) 25(7) 2497-2509Abstract
The biological and neurological processes during the lifespan are dynamic with significant alterations associated with different stages of life. The phase and coupling of oxy-hemoglobin (Δ[HbO]) and deoxy-hemoglobin concentration changes (Δ[Hb]) measured by functional near-infrared spectroscopy (fNIRS) are shown to characterize the neurovascular and metabolic development of infants. However, the changes in phase and coupling across the human lifespan remain mostly unknown. Here, fNIRS measurements of Δ[HbO] and Δ[Hb] conducted at two sites on different age populations (from newborns to elderly) were combined. Firstly, we assessed the influence of random noise on the calculation of the phase difference and phase-locking index (PLI) in fNIRS measurement. The results showed that the phase difference is close to π as the noise intensity approaches -8 dB, and the coupling strength (i.e., PLI) presents a u-shape curve as the noise increase. Secondly, phase difference and PLI in the frequency range 0.01-0.10 Hz were calculated after denoising. It showed that the phase difference increases from newborns to 3-4-month-olds babies. This phase difference persists throughout adulthood until finally being disrupted in the old age. The children's PLI is the highest, followed by that of adults. These two groups' PLI are significantly higher than those of infants and the elderly (p < 0.001). Lastly, a hemodynamic model was used to explain the observations and found close associations with cerebral autoregulation and speed of blood flow. These results demonstrate that the phase-related parameters measured by fNIRS can be used to study the brain and assess brain health throughout the lifespan.
生命周期中的生物和神经过程是动态的，与生命的不同阶段相关的显着变化。通过功能性近红外光谱 (fNIRS) 测量的氧合血红蛋白 (Δ[HbO]) 和脱氧血红蛋白浓度变化 (Δ[Hb]) 的相位和耦合可以表征婴儿的神经血管和代谢发育。然而，人类一生中相位和耦合的变化仍然大多未知。在这里，结合了在不同年龄人群（从新生儿到老年人）的两个地点进行的 Δ[HbO] 和 Δ[Hb] 的 fNIRS 测量。首先，我们评估了随机噪声对 fNIRS 测量中相位差和锁相指数 (PLI) 计算的影响。结果表明，随着噪声强度接近-8 dB，相位差接近π，耦合强度（即PLI）随着噪声的增加呈现出U型曲线。其次，计算去噪后0.01-0.10 Hz频率范围内的相位差和PLI。它表明，从新生儿到 3-4 个月大的婴儿，相位差会增加。这种相位差异在整个成年期都持续存在，直到最终在老年时被破坏。儿童的PLI最高，其次是成人。这两组的PLI明显高于婴儿和老年人（p<0.001）。最后，使用血流动力学模型来解释观察结果，发现与脑自动调节和血流速度密切相关。这些结果表明，fNIRS 测量的相位相关参数可用于研究大脑并评估整个生命周期的大脑健康状况。
Links
http://www.ncbi.nlm.nih.gov/pubmed/33493123http://dx.doi.org/10.1109/JBHI.2021.3053900
