In this work we demonstrate that functional infrared imaging is capable of detecting low frequency temperature fluctuations in intact human skin and revealing spatial, temporal, spectral, and time-frequency based differences among three tissue classes: microvasculature, large sub-cutaneous veins, and the remaining surrounding tissue of the forearm. We found that large veins have stronger contractility in the range of 0.005-0.06 Hz compared to the other two tissue classes. Wavelet phase coherence and power spectrum correlation analysis show that microvasculature and skin areas without vessels visible by IR have high phase coherence in the lowest three frequency ranges (0.005-0.0095 Hz, 0.0095-0.02 Hz, and 0.02-0.06 Hz), whereas large veins oscillate independently.

在这项工作中，我们证明了功能性红外成像能够检测完整人体皮肤中的低频温度波动，并揭示三种组织类别之间基于空间、时间、光谱和时频的差异：微血管系统、大皮下静脉和前臂剩余的周围组织。我们发现，与其他两种组织类别相比，大静脉在 0.005-0.06 Hz 范围内具有更强的收缩性。小波相位相干性和功率谱相关性分析表明，红外可见的微血管和没有血管的皮肤区域在最低三个频率范围（0.005-0.0095 Hz、0.0095-0.02 Hz 和 0.02-0.06 Hz）具有高相位相干性，而大静脉独立振荡。