We demonstrated 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 vessels 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. A clinical protocol is underway to try to associate temperature oscillations with oscillations of microcirculation measured by laser speckle imaging and laser blood flow probes.
| Webb, R Chad; Ma, Yinji; Krishnan, Siddharth et al. (2015) Epidermal devices for noninvasive, precise, and continuous mapping of macrovascular and microvascular blood flow. Sci Adv 1:e1500701 |
| Chang, Ken; Yoon, Stephen; Sheth, Niral et al. (2015) Rapid vs. delayed infrared responses after ischemia reveal recruitment of different vascular beds. Quant Infrared Thermogr J 12:173-183 |
| Balageas, Daniel L; Roche, Jean-Michel; Leroy, François-Henri et al. (2015) THE THERMOGRAPHIC SIGNAL RECONSTRUCTION METHOD: A POWERFUL TOOL FOR THE ENHANCEMENT OF TRANSIENT THERMOGRAPHIC IMAGES. Biocybern Biomed Eng 35:1-9 |
